The time-domain airborne electromagnetic (AEM) method is an efficient geophysical exploration technique. Yet, due to the presence of the induced polarization (IP) effect, electromagnetic (EM) data from late-time channels often exhibit a phenomenon known as sign reversal. The traditional imaging and inversion methods without considering the IP effect cannot recover the real electrical structure of the underground, so it is necessary to develop the EM forward and reverse modeling technology with IP effect. This study introduces a three-dimensional (3D) forward algorithm for AEM with IP effect in the time-domain built upon the unstructured finite-element method. To capture the IP effect within the medium, we use the Debye model, transforming it into a derivative form in the time-domain through frequency-time conversion. For temporal discretization, an unconditionally stable second-order backward Euler's scheme is applied. Maxwell’s equations are discretized in space using a vector finite element method based on an unstructured tetrahedral mesh. The algorithm's accuracy is verified through a comparison with the 1D semi-analytical solution of the uniform half-space model. We compute EM responses for both a half-space and 3D geological formations under various polarization conditions. We observe that the polarization characteristics of surrounding rocks and anomalous bodies can be effectively identified according to the attenuation characteristics of the AEM response curves. In addition, by studying the characteristics of the influence of IP parameters on the time-domain AEM system, we show that the larger the resistivity of the geological body or the larger the chargeability, the stronger the IP effect.

The recognition and classification of lithological information hold significant importance for categorizing oil and gas reservoirs and evaluating the compressibility of reservoir rocks. This study presents enhancements to the deep learning  network U-Net and conducts a comparative validation using experimental data from  central depression  of  Songliao Basin. We propose a more suitable feature attention fusion Unet (FAF-Unet) designed for well logging data. The selection of logging data primarily involves sensitivity analysis to identify characteristic parameters, including natural potential, acoustic time difference, photoelectric absorption cross-section index, wellbore diameter, density, natural gamma, and deep and shallow lateral resistivity. These parameters are analyzed to understand reservoir rock lithology. FAF-Unet is a network that amalgamates residual blocks and channel attention mechanisms. Residual blocks can better retain the data with lower-level features of the depth direction, and channel attention mechanisms can make up for the problem of ignoring the connection between  horizontal channels during vertical convolution. Comparing the accuracy and recall of six recognition methods, including support vector machine, decision tree, U-Net, U-Net with effective channel attention (ECA) mechanism, U-Net with residual block (Res-Unet), and FAF-Unet with both ECA and residual block, experimental results demonstrate that FAF-Unet achieves an accuracy and recall rate exceeding 89.00%. FAF-Unet outperforms the other five methods in terms of recognition performance and exhibits a narrower fluctuation range between accuracy and recall.

Due to surface obstacles or economic constraints, seismic data recorded is often incomplete. Consequently, seismic data reconstruction is an important topic in seismic research. This study presents a seismic data reconstruction approach based on joint accelerated proximal gradient and log-weighted nuclear norm minimization. The process begins by subjecting the original seismic data to low-rank preprocessing through texture-patch operators. Subsequently, the accelerated proximal gradient algorithm is employed for an initial reconstruction of the low-rank seismic data. Finally, an algorithm based on the log-weighted nuclear norm is presented to tackle the optimization problem and reconstruct the missing data. For synthetic seismic data and real seismic data, the reconstruction results of the joint accelerated proximal gradient and log-weighted nuclear norm method have improved both in quantitative and qualitative analysis: The signal-to-noise ratio of the synthetic data set with a 40% missing rate is 26.135 7 dB and the reconstruction error is 6.789 4; The signal-to-noise ratio of the Mobil Avo Viking Graben Line 12 data set with a 30% missing rate is 17.247 8 dB and the reconstruction error is 4.762 5; The signal-to-noise ratio of the Netherlands F3 data set with a 60% missing rate is 26.058 1 dB and the reconstruction error is 7.464 1.

Reverse-time migration (RTM) is widely employed for its ability to produce high-resolution imaging results. Nevertheless, wavefield extrapolation based on the two-way wave equation often leads to pronounced low-frequency noise under cross-correlation imaging condition. This issue significantly impacts the quality of the resulting images. In this study, we introduce a convolution-deconvolution neural network (DeCNN) built upon the U-Net architecture to mitigate the presence of low-frequency noise in RTM. We utilize source-normalized imaging results with  low-frequency noise as training data， and the Laplace filtering results   as labels to abtain  the neural network model, grounded in a data-driven approach. The comparison results of   model trials and transfer learning demonstrations highlight the superior denoising proficiency of  DeCNN. It outperforms  U-Net, effectively suppressing noise in scenarios such as the transfer  SEG/EAGE standard salt dome model and  Marmousi model. In contrast to conventional techniques aimed at mitigating low-frequency noise through up and down traveling wave decomposition, DeCNN  can input the source-normalized imaging results into the network after training, and the network can output high resolution imaging results in seconds. The efficiency is much higher than that of conventional low-frequency noise suppression methods using wavefield decomposition, and it has certain advantages in noise suppression effect.

Aiming at the problems of underwater distributary channel sand body, such as thin single layer thickness, serious superimposition and crossing, strong lateral heterogeneity, and poor consistency of well seismic relationship, this study presents a prediction method of CV-XGBoost reservoir thickness based on cross validation. Firstly, correlation analysis and multicollinearity evaluation are used to remove redundant attributes, then the model training and parameter set optimization are carried out, and finally thickness prediction is carried out with verification set. The results show that: 1) For reservoir prediction with few samples, it is necessary to do cross validation to improve the accuracy of reservoir prediction; 2) XGBoost uses a regular term with the second order partial derivative to control the convergence progress of the model, and its prediction accuracy is better than that of conventional LASSO (least absolute shrinkage and selection operator) regression, GBDT (gradient boosting decision tree) and SVM (support vector machine) methods; 3) The reservoir prediction results with low verification set ratio can be used to understand the macro distribution of sand body, and the higher verification set ratio is helpful to improve the accuracy of sand body description; 4) The average amplitude, average energy, arc length and dominant frequency in this study area are the attributes that contribute greatly to thickness prediction.

This study focuses on measuring the physical parameters of rock samples sourced from diverse geological units within the geological corridor of western Liaoning Province. For igneous and sedimentary rocks, we establish both qualitative and semi-quantitative relationships between density, elastic wave velocity, magnetic susceptibility, resistivity and spectral data, and study the correlation between petrophysical properties and rock characteristics, so as to study the diagenetic environment of rocks. Through statistical analysis of correlation coefficient curves specific to different rock types, we present a comprehensive summary of the interplay between rock types and strength of correlation coefficient between spectral reflectance and the intensity of correlations with density, elastic wave velocity, magnetic susceptibility, and resistivity. According to the characteristics of strength of correlation, it is analyzed that the difference of diagenetic environment leads to different physical properties of different rocks. The physical sedimentary environment of sedimentary rocks fosters a robust correlation between its spectral reflectance and both density and elastic wave velocity. The stable diagenetic setting of igneous rock yields a strong connection between its spectral reflectance and magnetic susceptibility. The spectral reflectance of both sedimentary and igneous rocks exhibits a positive correlation with density and elastic wave velocity.

Understanding the characteristics of urban land expansion is essential for managing the uncontrolled growth of construction areas during the urbanization process. Four representative cities, namely Shenyang, Dalian, Chaoyang, and Dandong, located in various directions within Liaoning Province, were chosen for this study. Employing remote sensing image data from 1990, 2000, 2010, and 2020, the research employed metrics such as the proportion of construction land, expansion intensity index, expansion intensity difference index, and the public edge measurement method to investigate the distinctive attributes of urban construction land within the designated area. The findings reveal significant variations in the spatial expansion of construction land across the four cities. Between 1990 and 2020, the overall share of construction land expanded considerably from 4.74% to 11.58%. During this period, the order of expansion intensity shifted from high to low as follows: Shenyang, Dalian, Dandong, and Chaoyang. Notably, Dalian exhibited rapid expansion, Shenyang and Dandong initially underwent slow expansion, transitioning to higher rates during the second and third phases, Chaoyang expanded from low speed to high speed, and then to medium speed. Over the same period, the divergence in urban expansion trends of  Shenyang, Chaoyang, and Dandong diminished gradually, while Dalian experienced an increasing discrepancy in its expansion pattern. The four cities employed a combination of three expansion modes, with predominant reliance on sprawl development, followed by enclave development, infill development was relatively minimal. The overarching urban growth trend revolved around outward development. However, distinct development needs led to variations among the cities.

Sulfur plays an important role in the formation of magmatic sulfide deposits. Based on the drill core data of the Voisey’s Bay nickel-copper sulfide deposit in Labrador, Canada, the correlation between nickel and copper mass fraction and sulfur mass fraction was analyzed by support vector machine (support vector machine, SVM) and kernel function based on radial basis function (radial basis function, RBF), and the prediction model of sulfur was established based on     sulfur mass fraction. In the prediction model, nickel and copper mass fractions are used as independent variables, sulfur mass fraction is used as the dependent variable, the predicted value of sulfur mass fraction is calculated by SVM to fit the original value. According to the calculation results of the fitting curve, the sulfur evolution can be divided into three stages: In the sulfur saturation stage, the mass fraction of sulfur element is 3.12×10-6-20.80×10-6, the variance is less than 1.44×10-7, the fractal dimension is 0.35, λ>0, and the stage is chaotic; In the mineralization stage, the mass fraction of sulfur element is 6.60×10-7-17.80×10-7, the variance is less than 1.37×10-9, the fractal dimension is 0.60, λ>0, and the stage is chaotic; In the sulfur loss stage, the sulfur mass fraction is 2.00×10-8-38.0.×10-8, the variance is less than 1.56×10-10, the fractal dimension is 0.94, λ=0, and the stage is stable. The results show that the mass fraction of nickel, copper and sulfur in the immiscible sulfur-saturated magma is not linearly or simply nonlinearly correlated, but staged nonlinearly.

The Erdaokan Ag-Pb-Zn deposit is a large Triassic Ag-Pb-Zn deposit newly discovered in the Duobaoshan metallogenic belt, Heilongjiang Province. Till now, little research has been conducted on  its formation mechanism, and its genesis is not clear yet. We selected the hydrothermal rhodochrosite as the research object, and systematically studied its mineralogical properties and geochemical characteristics by using optical microscope and LA-ICP-MS dating. The results show that the rhodochrosite is characterized by strong negative Eu anomaly and positive Ce anomaly, enrichment of light rare earth elements, and depletion of heavy rare Earth elements. In addition, the fractionation degree of light rare Earth elements  is significantly higher than that of the heavy rare earth elements, showing an overall right REE  distribution curve. On this basis，it is considered that the rhodochrosite in the Erdaokan Ag-Pb-Zn deposit was formed in a reducing environment, and the ore-forming materials  came from mixed sources. The deep ore-forming materials from the mantle, the carbonaceous shale and limestone near the ore all have important contributions to the formation of rhodochrosite.

Quartz porphyry veins and granite porphyry veins are developed in the Dubi area of Zhengxiangbai Banner, Inner Mongolia, and are structurally located in the Bainaimiao island arc belt on the northern margin of the North China craton. Through LA-ICP-MS zircon U-Pb dating, the diagenetic ages of the quartz porphyry and granite porphyry are (127.8±2.1) and (128.8±0.7) Ma, respectively, and both are products of the Early Cretaceous magmatism. Petro-geochemically, the quartz porphyry is rich in silica (w(SiO₂) 76.06%-77.20%) and potassium (w(K₂O) 4.66%-6.48%), high TFeO/MgO ratio (10.42-12.55), higher 10000Ga/Al ratio (2.71-3.27), low w(CaO)(0.58%-0.70%). w(Al₂O₃) is 11.63%-12.67%, and the aluminum saturation index(A/CNK) is 1.08-1.15. The granite porphyry is rich in silica (w(SiO₂) 70.67%-71.88%) and potassium (w(K₂O) 5.83%-6.45%), high TFeO/MgO ratio (10.91-12.10), higher 10000Ga/Al ratio (2.64-3.03), and low w(CaO) (0.33%-0.44%). w(Al₂O₃) is 14.47%-15.14%, and the aluminum saturation index is 1.14-1.16. Their REE distribution curves show “seagull” right-leaning  pattern with obvious negative Eu anomalies. They are relatively rich in Rb, Th, K, Zr, Hf etc., and depleted in Sr, Ba, Ti, P, etc., indicating the characteristics of aluminous A-type granite. The zircon εHf(t) values of quartz porphyry and granite porphyry are －1.56-1.85 and －0.87-2.14, respectively, and the two-stage model ages(TDM2) are 1 281-1 067 Ma and 1 240-1 046 Ma, respectively, indicating that the two rocks are the products of  mixed materials from the crust and mantle. Combined with the regional tectonic evolution, it is considered that the quartz porphyry and granite porphyry were formed in the intraplate extensional environment during the thinning of the Early Cretaceous lithosphere on the northern margin of the North China craton.

The large-scale gold mineralization in Jiaodong Peninsula occurred in 125-110 Ma. Coincided with the mineralization period, the Early Cretaceous the Dazeshan and Tianzhushan plutons  are distributed in the eastern margin of the North China craton. Based on the studies of the petrography, geochemistry, zircon LA-ICP-MS U-Pb dating, and Lu-Hf isotopic constitution, in this paper, the petrologic classification, forming age, magmatic source, petrogenesis and tectonic dynamic background are discussed. The Dazeshan and Tianzhushan plutons are characterized by w(Na₂O) >3.68, 1.0δEu=0.49-0.64). They are a set of weakly peraluminous high potassium calc-alkaline rocks, showing the characteristics of I-type granites. The LA-ICP-MS zircon U-Pb ages of the Dazeshan and Tianzhushan plutons are (120±1) and (112±2) Ma, respectively. They are the late Early Cretaceous magmatic rocks of the Mesozoic in Jiaodong, and the products of different evolution stages of the same period. Their zircon εHf(t) values are －15.3-－10.7 and －21.8-－14.1, respectively, and the two-stage Hf model ages (TDM2) vary in the range of 2.15-1.86 Ga and 2.55-2.07 Ga, respectively. According to their petrology, geochemistry and Lu-Hf isotopic constitution, combined with the results of previous studies, the authors believe that the Dazeshan and Tianzhushan granites are the products of lithospheric thinning and intracontinental extension, and the diagenetic materials are mainly derived from the partial melting of the ancient crustal materials with the addition of some mantle materials. In the early stage, the Dazeshan pluton was formed at the same time as a large number of dark dykes in the Jiaodong area, and more mantle materials were added, which led to the decrease of the two-stage Hf model ages of the Dazeshan pluton.

The Erdene granite in Southern Mongolia is located on the western margin of the massive Cretaceous magmatic granite in the whole Northeast Asia. The zircon U-Pb geochronology, rock geochemistry and zircon Hf isotopes in the Erdene region were studied to determine the formation age, petrogenesis, and tectonic setting.The main rock type is biotite granite. The zircon LA-ICP-MS U-Pb dating yields  a weighted mean age of (123.4±1.4) Ma, indicating that it formed in the Early Cretaceous. The granite has high silicon(w(SiO₂）=71.01%-72.66%), high alkali(w(Na₂O+K₂O)=8.52%-8.90%), poor phosphorus(w(P₂O₅)=0.06%-0.11%), low magnesium and calcium（w(MgO)=0.27%-0.39%, w(CaO)=1.10%-1.27%)，and A/CNK=(1.05-1.07），indicating that it belongs to the metaluminous-peraluminous rock. It is characterized by enrichment of LILE(such as Rb, U,Th), depletion of HFSE(such as Ta, Zr, Hf) and depletion of Nb,Sr,Ba elements, with obvious negative Eu anomalies(δEu=0.11-0.15).The average magmatic temperature is 816  ℃. It belongs to A1 type granite. The εHf(t) of the rocks ranges from 2.54-7.92, and the TDM2 varies from 1 016-673 Ma, indicating that a little young materials might have been  added in the source region. Based on the regional extensional tectonics, it is believed that the large Erdene granite formed in an extensional thinning environment, which is related  to the decompression and melting of the middle and lower crust.

The basin edge slope area of Changling fault depression in Songliao basin is mainly composed of intermediate-basic volcanic rocks. At present，there is a lack of in-depth understanding of the lithology, lithofacies distribution pattern， and high-quality reservoir stratum development law of the intermediate volcanic rocks in the basin edge slope area. By taking Longfengshan area in Changling fault depression as an example, the spatial distribution characteristics of volcanic edifice and volcanic facies were described by making a comprehensive use of well drilling, well logging, and seismic data,the volcanic facies model and eruption model were established, and the development law of the high-quality reservoir stratum was discussed. The research results indicate that the volcanic eruption center is located in the basin edge slope zone near the high place of the basin edge and distributed along the fault. The proximal facies belt of the volcanic edifice is featured with interlayers of effusive facies and explosive facies. The central facies belt of the volcanic edifice is mainly composed of pyroclastic flow of thick explosive facies. The pyroclastic flow is further advanced to the sub-concave center of the basin and then transformed into volcanic deposit facies. The volcanic facies is jointly controlled by  multi-stage Plinian eruptions, the transport and placement of volcanic eruptions, and other factors. High-quality volcanic rock reservoirs are dominated by volcanic tuff and vesicular andesite with strong dissolution, which are located in the medial facies belt of the volcanic edifice on the basin edge slope. The proximal facies belts with lava flow developed are the favorable development parts of the volcanic reservoir stratum in the area. The research has certain directive significance in the oil-gas exploration of intermediate-basic volcanic rocks in the slope belt of the basin margin of a fault depression basin.

In order to clarify the strata and sedimentary filling characteristics of the Lower Jurassic Lianggaoshan Formation in eastern Sichuan basin, for effectively guiding the hydrocarbon exploration, this study comprehensively utilizes the research tools of outcrop survey, core observation and analysis of sedimentary petrology and petroleum geology. On the basis of systematically sorting out the stratigraphic structure and sedimentary facies in the study area, we further discuss the synergistic reservoir-forming rule between shale oil and gas and tight oil and gas under the constraints of sedimentary sequence. The results show that typical dichotomy sequence stratigraphic structure is developed in the study area. In the early lake transgression stage, the Lower Lianggaoshan Formation formed a landward stepping parasequence set, which was composed of delta front, prodelta, semi-deep lake and deep lake. In the late lake regression stage, a seaward stepping parasequence set is developed in the Upper Lianggaoshan Formation, which can be subdivided into three parasequences or subsections, showing the evolution from semi-deep lake to delta front, shore and shallow lake. The mudstones and shales of semi-deep lake, deep lake and prodelta facies are vertically superimposed with the sandstone bodies of underwater distributary channel in the delta front subfacies, forming various source-reservoir contact relationships, such as “self-generation and self-storage, lower generation and upper storage, side generation and side storage”. This provides a geological basis for the coordinated accumulation of shale oil and gas in the Lower Lianggaoshan Formation and tight oil and gas in the Upper Lianggaoshan Formation.

Aiming at clarifying the strongly heterogeneous Archean metamorphic rock buried hill reservoir in    Jinzhou   south,   the main controlling factors of the buried hill reservoirs are studied, and the development model of the buried hill reservoir in this area was established. Based on the data of drilling, coring, thin section, logging, and seismic, the characteristics of metamorphic buried hill reservoir are defined, the key factors controlling the reservoir development are discussed and the reservoir development model is established. The results show that: 1) Plagioclase gneiss, monzonite gneiss, cataclastic rock and diabase are developed in the study area, among which gneiss and cataclastic rock are the main lithology for reservoir development; Tectonic fractures, fractured intergranular pores and dissolution pores constitute a variety of reservoir spaces, among them tectonic fractures are the dominant. 2) Tectonic movement, lithology and weathering have an important control action on the high quality reservoirs distribution: reservoirs development degree of granite gneiss with high brittleness mineral content is superior to the basic intrusion; the reservoir thickness is large in the multi-stage fault superposition position; high position of the Paleo-geomorphology suffered strong weathering to further enhance the quality of the reservoir. Based on the above analysis, a reservoir development model considering tectonic position was established. Stably distributed reservoirs are developed in the platform area, thicker reservoirs are developed in the high slope area, the reservoir thickness changes fastest in the uplift area, the reservoir development in the low slope is relatively thinner, and the reservoir development in the depression area is the worst.

Modern geochemical analysis and biomarker analysis methods, the characteristics of Chang 7 Member and Chang 9 Member source rocks in Zaoyuan exploration area of Ordos basin were studied, and oil source correlation of Chang 4+5 Member Chang 61 Member and Chang 8 Member crude oil samples were carried out. The results show that the organic matter abundance of the source rocks of Chang 7 Member in the study area is higher, the type of organic matter is Ⅱ1-Ⅱ2, and the configuration of regular sterane C27-C28-C29 is V-shaped or partially V-shaped, which is the characteristic of sapropel; The organic matter abundance of Chang 9 Member source rocks is lower, the type of organic matter is Ⅱ2, and the configuration of regular sterane C27-C28-C29 is L-shaped, which is the characteristic of close mixing with terrestrial higher plants. The results show that the crude oil Pr/Ph ratios of Chang 4+5 Member, Chang 61 Member and Chang 8 Member are between 0.78 and 0.85, which indicate that their sedimentary environment belongs to a freshwater reducing environment; The crude oil of Chang 4+5 Member, Chang 61 Member and Chang 8 Member come from the same set of continental freshwater lake source rocks similar to Chang 61 Member, belonging to medium low mature crude oil. The crude oil of Chang 8 Member is more mature than that of Chang 4+5 Member and Chang 61 Member. The crude oil of Chang 4+5 Member, Chang 6 Member and Chang 8 Member in Zaoyuan exploration area is mainly from the dark mudstones, the main contributor is the Zhangjiatan shale of Chang 7 Member, and the dark mudstone of Chang 9 Member also makes a small contribution. 

 In Guyang, Inner Mongolia, a significant occurrence of Late Neoarchean (quartz) diorite-tonalite-trondhjemite-granodiorite (DTTG) rock assemblages has been identified. LA-ICP-MS zircon U-Pb dating has yielded crystallization ages of (2 504±11) and (2 514±7) Ma for the quartz dioritic and tonalitic gneisses, respectively. Additionally, the dioritic gneisses exhibit inherited zircon ages of ca. 2.6 Ga. The quartz dioritic (D) gneisses in Guyang display a relatively low w(SiO2) (62.08%-62.62%), Sr/Y ratios (23.3-39.8), and elevated concentrations of w(MgO) (2.08%-3.06%) and w(TFe2O3) (5.43%-6.01%). Notably, these rocks demonstrate either negligible or weak Eu negative anomalies (Eu/Eu* = 0.91-0.98) and show subtle differentiation between light and heavy rare earth elements ((La/Yb)N = 7.59-21.60). These features are indicative of island arc calc-alkaline geochemical signatures. Combining these characteristics with zircon Hf isotope compositions suggests that the late Neoarchean diorites likely formed through crustal partial melting under relatively low-pressure and shallow conditions. In contrast, the late Neoarchean tonalitic-trondhjemitic (TT) gneisses in the Guyang area exhibit higher w(SiO2) (67.95%-77.01%), elevated Sr/Y ratios (120.00-941.00), and lower w(MgO) (0.14%-1.29%) and w(TFe2O3) (0.63%-2.66%). They also feature significant Eu positive anomalies (Eu/Eu* = 1.48-8.73) and prominent differentiation between light and heavy rare earth elements ((La/Yb)N = 29.70-140.00). While the consensus attributes the origins of TTG rocks to partial melting of hydrated altered basalts, the geochemical signatures of the   Late Neoarchaean (quartz) diorite-tonalite-trondhjemite (DTT) rocks in the Guyang area allude to fractional crystallization of amphibole. A mixing simulation involving Guyang cumulative hornblendite and trondhjemite accurately reproduces the composition of quartz dioritic gneisses in the Guyang area. Thorough thermodynamic and trace element quantitative modelling reveals that the Late Neoarchean tonalic-trondhjemitic rocks likely formed through multistage fractional crystallization from dioritic magma in a water-rich and relatively low-pressure condition. Amphibole is the primary mineral phase involved in fractional crystallization, with minor amounts of plagioclase and sphene. The high whole-rock Sr/Y and Eu/Eu* values do not indicate sufficient conditions for a relatively high-pressure source.

Based on the comprehensive research on field geology, petrography, geochronology and geochemistry of the Early Cretaceous intermediate-acidic magmatic rocks of Xiaoxinancha copper (gold) deposit in Yanbian, Jilin Province, the isotopic ages are determined to be(101.69±0.61) Ma (quartz diorite), (101.14±0.58) Ma (tonalite), (100.82±0.62) Ma (granodiorite) and (100.20±1.10) Ma (diorite porphyrite). The magmatism occurred at the end of the Early Cretaceous (102-100 Ma), which is the product of the same tectonic evolution process. The diorite porphyrite has the geochemical characteristics of typical adakitic rocks, with w(SiO₂)=61.419%-62.153%， w(Al₂O₃)=16.872%-17.329%,w(MgO)=2.339%-2.643%,w(Na₂O)=5.749%-6.623%, w(K₂O))=1.483%-1.786%, w(Sr)=(691-888)×10^-6,w(Yb)=(0.71-0.83)×10^-6,Sr/Y=87.4-120.0.The enrichment of LREE is formed by the in-situ intrusion of adakitic magma generated by partial melting of the subducted oceanic slab. The adakitic magma mixed with the acidic magma produced by the remelting of the lower crust during the upwelling process to form the enriched mantle source magma which was upwardly emplaced, and formed the calc-alkaline granitic complexes such as quartz diorite, tonalite and granodiorite. The magmatic hydrothermal fluid is mixed with atmospheric precipitation during the ascent along the regional faults, extracted the metallogenic materials in the surrounding rocks, and formed the metallogenic hydrothermal fluid rich in copper (gold) components, and unloaded and precipitated at a suitable location to form vein-type copper (gold) mineralization. Yanbian area was located in the continental margin environment where the paleo Pacific plate subducted to the Eurasian plate in the Late Mesozoic. The subduction of the paleo-Pacific plate was the direct driving force for the formation of Early Cretaceous quartz diorite, tonalite, granodiorite, diorite porphyrite (dikes)and hydrothermal vein-type copper (gold) mineralization in Xiaoxinancha deposit.

The skarn-type scheelite deposit is an important type of tungsten deposits in eastern Jilin and Heilongjiang of Northeast (NE) China. The large-scale Cuihongshan Wo-polymetallic deposit in Xunke area of Heilongjiang Province and medium-scale Baishilazhi scheelite deposit in Wangqing area of Jilin Province are two representative skarn deposits. To determine their ore-forming fluid characteristics and metallogenic mechanism, scheelite single minerals were selected from these two representative deposits for in-situ LA-ICP-MS trace elements analysis. The results show that the scheelite in Cuihongshan deposit was formed in a Na- and Nb-rich ore-forming fluid system with left-dipped rare earth element (REE) distribution patterns and weak positive Eu anomalies. The substitution of REE3+ for Ca2+ in scheelite from Cuihongshan deposit can be accounted for the substitution mechanism: 2Ca2+ = REE3+ + Na+ and Ca2+ + W6+ = REE3+ + Nb5+. The scheelite in Baishilazi deposit was formed in a Na- and Nb-poor ore-forming fluid system with right-dipped REE distribution patterns and positive Eu anomalies. The substitution mechanism of REE3+ for Ca2+ in scheelite of Baishilazi deposit is 3Ca2+ = 2REE3+ + □Ca (where □ is a site vacancy). The obvious correlation between EuN and Eu*N and the high Mo content in scheelite samples indicates that the ore-forming fluids in two skarn-type tungsten (-polymetallic) deposits in eastern Jilin and Heilongjiang are oxidizing fluids. The Eu anomalies of scheelite in these two deposits are higher than those of their ore-forming intrusions, indicating that water-rock reaction occurred during the fluid evolution. The obvious correlation of Y and Ho contents between the scheelite in different deposits and their ore-forming intrusions, as well as the differences between Y/Ho and La/Ho, reveal that their initial ore-forming fluids are derived from magmatism, and water-rock reaction and fluid mixing occurred during the fluid evolution. Due to data from this studies and previous references, it can be concluded that the water-rock reaction and fluid mixing during ascending of the magmatic hydrothermal are major mechanisms of scheelite mineralization in the skarn-type tungsten (-polymetallic) deposit in eastern Jilin and Heilongjiang.

The Gema Pb polymetallic deposit was discovered by our team in 2010. It is currently the only medium-sized Pb-Zn-Ag polymetallic deposit in the eastern section of Bangong Lake-Nujiang metallogenic belt. The deposit is located in the eastern section of the Anglonggangri-Bange-Tengchong magmatic arc zone. The ore bodies are produced in the surrounding rocks of the outer contact zone of the Early Cretaceous granodiorite in the form of veins. The shapes and locations of the ore bodies are strictly controlled by two groups of faults in the nearly east-west and northwest directions. The ore-bearing surrounding rocks are sandstone and siltstone of the Mali Formation (hornfelization) of the Middle Jurassic. Based on the geological characteristics of the Gema Pb polymetallic deposit and the studies of the geochemistry of the surrounding rocks and ores, and the LA-ICP-MS zircon U-Pb chronology of granodiorite, this paper examined the source of ore-forming materials, the ore-forming age and the ore-forming geological background, also discussed the ore-forming process of the deposit, and established a preliminarily metallogenic geological model of the Pb-Zn-Ag polymetallic deposit in the eastern section of the Bangong Lake-Nujiang  metallogenic belt. The results show that the granodiorite in the area has low silicon, high aluminum and relatively rich potassium, which is the product of magmatism in the subduction stage before plate collision. The LA-ICP-MS zircon U-Pb dating of granodiorite yields an age of (119.86 ± 0.45) Ma, indicating an Early Cretaceous diagenetic age. The rare earth element (REE) of granodiorite, ore and surrounding rocks show enrichment in light REEs, depletion in heavy REEs, and a negative Eu anomaly, suggesting a common origin. Compared to the abundance values of Chinese continental crust, the granodiorite contains relatively enriched Pb and Ag, while Zn is deficient. In the metamorphic siltstone of Mali Formation, Pb and Ag are extremely strong enriched elements, and Zn is also strongly enriched. The ore-forming materials of this deposit are derived not only from granodiorite but also from the surrounding rocks of Mali Formation, indicating obvious “double source” feature. The deposit was formed in an island arc environment before the closure of the Bangong Lake-Nujiang Ocean basin. The ore forming age is Early Cretaceous, and the genetic type of the deposit is a post-magmatic hydrothermal deposit.

Accurate prediction of shallow underground temperature is of great significance for reducing investment risks and promoting the development and utilization of shallow geothermal energy. In this study, a hybrid model based on particle swarm optimization (PSO) and extreme gradient boosting (PSO-XGB) was developed and compared with single models including K-nearest neighbors (KNN), support vector regression (SVR), random forest (RF), and extreme gradient boosting(XGB). Firstly, 54 sets of borehole data were collected, and the dataset was expanded using Kriging interpolation. Latitude and longitude coordinates, annual average rainfall, annual average temperature, and distance to faults were used as input features for predicting the temperature at a depth of 100 meters underground. Then the performance of the models was evaluated using metrics such as root mean squared error, mean absolute error, coefficient of determination, andmean squared error. The results showed that the PSO-XGB hybrid model outperformed the single models in terms of predictive performance. The ERMS is 0.070 6, the EMA is 0.054 9, the R2 is 0.962 0, and the EMS is 0.005 0, which is significantly higher than the other models in terms of precision and degree of fitting. Therefore, the PSO-XGB hybrid model is superior to the single model in prediction performance.

The lunar penetrating radar (LPR) data play an essential role in studying the lunar soil layer structure of the Von Karman crater on the back of the moon and analyzing the lunar chronological activities. Because the geological conditions of the Chang’e-4 landing area are complex, using advanced radar data processing technology and methods to obtain high-precision LPR imaging results is an important basis for lunar-related scientific research. Based on previous studies, the focusing algorithm based on the synthetic aperture focusing technique (SAFT) migration imaging is performed on the Chang’e-4 LPR 500 MHz data in this paper. Compared with the traditional f-k migration results, the method improved the imaging resolution. The proposed SAFT method can more finely reflect the vertically layered structure and horizontal interface fluctuation of the lunar soil layer. The LPR data interpretation section indicates that the lunar soil layer contains a shallow topsoil layer of about 12 m from Finsen crater within a depth of 40 m, about 17 m from the sputter layer of the crater around Von Karman and the lowest basaltic rock layer. 

Hainan Island is located at the intersection of Pacific, Indo-Australian and Eurasian plates. It is an ideal location to reveal the tectonic evolution of plate tectonics. In order to gain a better understanding of the Early Paleozoic tectonic evolution of the island, systematic zircon U-Pb geochronological and Hf isotopic analyses of the andesite from the northwestern Hainan Island have been carried out. The results of zircon U-Pb dating show that two representative andesite samples yield ages of LA-ICP-MS(448±5) Ma and (447±11) Ma, respectively. This suggests that Early Paleozoic (Late Ordovician) magmatism occurred on the Island. In-situ zircon Hf isotopic results show that the εHf(t) values of the andesites are -16.48-5.22 and their two-stage model ages (TDM2) are 2 030-953 Ma. Combined with regional geological data, it is evident that the andesites were produced by mixture of mafic and felsic magmas, and their formation is related to the subduction of the Proto-Tethys Oceanic crust.

In the long-term mining process of the fractured thermal reservoir of the enhanced geothermal system (EGS), due to the constant extraction of heat from the high-temperature dry hot rock mass, the temperature of the high-temperature granite mass drops, which induces the secondary fracture of the rock mass, and even the occurrence of fluid short circuit reduces the mining efficiency of the geothermal system. In order to ensure the stable extraction of EGS heat energy, it is necessary to establish the coupling model of fluid-solid heat transfer, hydrodynamic and fracture deformation in the test site, and analyze the influence of hydrodynamic and thermal effects on the fracture development law of the reservoir. Based on the test data of circulating water injection at the EGS development site in Matouying Bulge area, Hebei Province, this paper established a coupling model of thermo-hydro-mechanical (THM) of microfractures in the site. The accuracy of the THM coupling model was verified by comparing the model simulation results with the field observation results. The increase of permeability of EGS reservoir and the spatial range of stimulation zone reveal that the range of stimulation zone of reservoir fracture is affected by temperature, pressure and injection flow. The results show that increasing the water injection pressure can stimulate the shear fracture of existing fractures and broaden the area of stimulation zone. Reducing the temperature of water injection can improve the permeability of fluid and expand the reservoir stimulation zone. In the initial stage of hydraulic fracturing, the proper use of cold water injection is conducive to improving the reservoir permeability, and increasing the injection flow will expand the range of reservoir stimulation zone.

 In order to analysis the temporal and spatial evolution characteristics and influencing factors of groundwater level in the mountain-front alluvial plain of Hutuo River in Shijiazhuang under the influence of human activities, based on the data of precipitation, groundwater level depth, groundwater exploitation, population and GDP in the study area, the average groundwater level variation map and groundwater flow field of different stages are drawn, and the temporal and spatial evolution characteristics of groundwater flow field are discussed. On this basis, the mechanisms by which human activities (groundwater extraction, artificial governance), natural factors (precipitation) and other factors (population, GDP, land-use type) influence the dynamics of the groundwater level are fully analised. The results show that: 1) On the time scale, the buried depth of groundwater level in the study area increases slowly from 1980 to 2000, increases rapidly from 2000 to 2015, and decreases from 2015 to 2021, and 2016 is the turning point. 2) Groundwater funnel area in Shijiazhuang urban area is large from 1980 to 2015, and groundwater confluence occurs in the funnel area. After 2015, groundwater funnel area in the study area gradually decreases and the confluence gradually disappears. 3) Precipitation and agricultural exploitation of groundwater are the dominant factors in the change of groundwater table from 1980 to 2000, industrial exploitation of groundwater is the dominant factor from 2000 to 2015, and artificial governance is the dominant factor from 2015 to 2021. 4) Population, GDP and land use types indirectly affect the groundwater depth in the study area, and the variation of groundwater depth in the mountain-front alluvial plain of Hutuo River in Shijiazhuang has obvious stage characteristics.

 The ophiolite mélange is an ideal laboratory for studying the process of ocean-continent transition and plate tectonics to intracontinental tectonic transition. In this paper, the petrology and geochemical characteristics of major and rare earth elements of siliceous rocks were studied to judge the origin and forming environment of Bangong Lake ophiolite mélange in Tibet. The siliceous rocks occur as intercalated beds in Shamuluo Formation or fault-fragments in basalt, exhibit cryptocrystalline texture, bioclastic texture and massive structure, and contain abundant Late Jurassic-Early Cretaceous radiolarite. They have a SiO2 content of 73.80% to 90.44%,  and a high Al2O3 content of 3.67% to 12.33%. The ratios of MnO/TiO2, Fe2O3/SiO2, Fe2O3/TiO2, and Al2O3/(Al2O3+Fe2O3) range from 0.14 to 0.91, 31.44 to 141.88, 1.83 to 11.80, and 0.66 to 0.96, respectively. After standardization of rare earth elements in North American shale, it shows a flat rare earth distribution pattern, with Ce showing a negative anomaly overall and Eu showing a weak positive anomaly overall; δCe values is 0.77 to 2.03, δEu value is 0.99 to 2.11. The values of (La/Yb) N, (La/Ce) N, (La/Lu) N, (La/Sm) N, (Ce/Yb) N, and (Gd/Lu) N are 0.43 to 1.12, 0.51 to 1.27, 0.44 to 1.26, 0.59 to 1.12, 0.41 to 2.01, and 0.82 to 1.16, respectively. After standardization, the rare earth element chondrite shows a right-leaning rare earth distribution pattern, with overall Ce showing weak positive anomalies and overall Eu showing negative anomalies. The authors propose that the formation environment of the siliceous rocks is not a typical continental margin, but rather a certain distance from the continental margin between ocean basin and continental margin. In combination with the results of area studies, the formation environment of the Bangong Lake ophiolite mélange is preliminarily identified as a back arc ocean basin environment, which is the product of the northward subduction of the Bangong Lake-Nujiang Ocean basin in the Late Jurassic. 

As an essential part of seismic data acquisition, a seismic source directly affects the seismic exploration effect. In seismic exploration, the ground surface is complex in many areas. Therefore, it is necessary to study the directional theory of phased-array vibrator systems under complex surface conditions. In this paper, based on the excitation principle of a phased-array vibrator system on a complex surface, the finite-difference numerical simulation method, and the theory of wave equation seismic illumination analysis, we carry out the forward modeling and seismic illumination analysis of the seismic wave field of the phased-array vibrator system for the simple theoretical model and the Marmousi model of the undulating surface. The model test results show that the phased-array vibrator system can excite the seismic wave directionally under complex surface conditions, and changing the seismic source's excitation delay can adjust the wave field's propagation direction to improve the signal-to-noise ratio of the target data. The method applies to the simple model of horizontal layers, the model of the wedge-shaped structure, and the complex Marmousi model. 

The FY-3B satellite has the characteristics of a high frequency of observation and wide imaging range, which can provide long-term observation data for maize leaf area index (LAI) inversion research. Long short-term memory (LSTM) algorithm has the ability to extract temporal features from multi-period data and solve complex nonlinear problems between spectral data and LAI. The study was conducted based on   LAI and reflectance spectrum data of spring maize in Jinzhou City,Liaoning Province  measured  near the ground. To construct the LAI inversion model, the spectral response functions were used to simulate the FY-3B multi-spectral band data combined with 28 vegetation indices highly correlated with spring maize LAI. The inversion models were conducted using LSTM of different hidden layers, and the accuracies of the LSTM models were compared with the accuracy of the partial least-squares regression (PLSR) model. The results showed that the number of hidden layers greatly influences the fitting ability of the LSTM model. The three-layer LSTM model increased the LAI estimation accuracy R2 from 0.818 3 (single-layer LSTM), 0.780 0 (PLSR) to 0.869 2; correspondingly reducing the RMSE from 0.509 1,0.490 6 to 0.372 6. In short, the accuracy of the model was significantly improved.

The paleosedimentary environment during the preservation of volcanic materials is one of the key factors influencing the volcanic oil-gas reservoir. During the interval of volcanic eruption, the deposited thin sedimentary lithologic layer has sedimentary characteristics. The trace elemental characteristics in the thin sedimentary layers are closed related to the paleosedimentary oxide-reductive environment and are important parameters for paleoenvironment identification. Thus, the paleosedimentary environment can be identified indirectly based on the trace element analysis on cores of the thin sedimentary layers during volcanic eruption intervals. Thin sedimentary lithologic layers, including mudstone and siltstone, had deposited during the interval of volcanic eruption in the Upper Carboniferous Haerjiawu Formation of Malang sag, Santanghu basin, Xinjiang. Eleven types of trace element ratios of these fine sediments, including U/Th, authigenic U, V/Cr, Ni/Co, V/Sc, V/(V+Ni), Cu/Zn, Fe3+/Fe2+, Sr/Ba, V/Zr, and B/Ga are used to trace the oxide-reductive paleoenvironment during the interval of volcanic eruption. Seven kinds of parameters, V/(V+Ni), V/Sc, Sr/Ba, V/Cr, V/Zr, Cu/Zn and B/Ga of mudstone, carbon mudstone, and siltstone indicate an underwater reduction environment and the coastal shallow sea environment with frequent water-land transition; It is concluded that the volcanic rocks of the Haerjiawu Formation are mainly deposited by eruption and preserved in underwater environment, and the complex sedimentary genetic environment of frequent water-land transition also exists.

 The fast dynamic time wrapping (fastDTW) algorithm  has the shortcomings of singularity in logging curves similarity measurement, and it's hard to find an appropriate search boundary. To overcome this issue, we combine the fastDTW algorithm with the SDTW (summation dynamic time warping) algorithm to obtain the fastSDTW algorithm,which solve the problem of outliers by reconstructing logging curves and integrating time series gradient information and numerical information. Next, an adaptive search boundary is proposed combined with  well-trajectory data. The fastSDTW algorithm is applied to measure the similarity of inclined and horizontal wells' logging curves based on the new boundary. The result shows that the fastSDTW algorithm based on adaptive search boundary has higher accuracy and time complexity of O(N), which ensures the operation speed of the algorithm. Furthermore, the algorithm is applied to the identification of water-flooded layers， and the  water-flooded layers are identified by comparing adjacent wells and  a good application effect is achieved.

In order to scientifically analyze the geological disaster susceptibility. This paper is based on the investigation and zoning of geological disasters in Helong City, and through the analysis of the distribution rules and influencing factors of geological disasters. Considering terrain, geology, meteorology, hydrology, soil vegetation and human engineering activities, combined with GIS technology and methods, 13 disaster causing factors including elevation, slope, aspect, curvature, lithology, distance from fault, rainfall, distance from water system, NDVI, soil texture, water erosion degree, population density and distance from road are extracted. Logistic regression and random forest model were used to evaluate the susceptibility of geological disasters, and the susceptibility zoning map was drawn. The result of random forest model shows: The very low susceptibility area is highest, reaching 56.98% of the total area, which is mostly located in the south of the study area; And the high and very high susceptibility areas account for up to 12.89%, which are located in the central and northeast, it is the key area for geological disaster prevention and management. NDVI, elevation, population density and rainfall are the main factors affecting disaster development, with a cumulative contribution rate of 58.12%. The ROC (receiver operating characteristic) curves and existing disaster density statistics of Logistic regression and random forest models show that the susceptibility zoning map are highly consistent with the actual disaster distribution, and their AUC (area under ROC curve) values are 0.856 and 0.907, respectively, which can achieve effective prediction and have good applicability. However, random forest model shows higher accuracy and stability, and its prediction performance is better than Logistic regression model.

The balance of exploitation and reinjection is an effective model for the sustainable development and utilization of hydrothermal geothermal resources. In order to simulate the temperature and pressure response of geothermal reservoir under different exploitation and reinjection scenarios, and to provide theoretical support for the sustainable development of geothermal resources, a mathematical model of Jixian system carbonate geothermal reservoir in Rongcheng geothermal field in Xiongan New Area was established by using numerical simulation technology. Firstly, COMSOL software was used to simulate the exploitation history data of existing geothermal wells in 300 km2 area. The simulation results are in good agreement with the monitoring data. Then, on this basis,the variation trends of temperature and pressure field of Jixian geothermal reservoir in the future 50 years under the single well exploitation model were predicted. Finally, according to the the declining trend of water level, the reinjection scheme was established, and the influence degree of different well spacing on the temperature field and pressure field of geothermal reservoir was analyzed. The results show that in the non-reinjection mode, the buried depth of water level decreases to 150 m in about 40 a, and the water level decreases about 1.13 m/a. The geothermal doublet system of  “one exploitation and one reinjection” scheme is adopted, and the well spacing is considered to be 600, 800 and 1 000 m respectively. Although increasing the well spacing reduces the number of arranged wells, it increases the exploitation amount and prolongs the thermal breakthrough time, so that more heat can be exploited. In practical engineering, the well spacing should be optimized by numerical simulation method to ensure the increase of production and prolong the thermal breakthrough time, so as to extract more heat.

The Tuanjiegou deposit, located in Jiayin County, Heilongjiang Province, is the largest epithermal gold deposit in Northeast China. This study systematically investigated the petrography, zircon U-Pb dating, whole-rock major and trace elements, LA-ICP-MS zircon in-situ trace elements and Hf isotopes of granodiorite porphyry and granite porphyry. Additionally, single mineral Pb-He isotope and LA-ICP-MS in-situ S isotope analyses of gold-bearing pyrite were conducted. The zircon U-Pb ages of granodiorite porphyry and granite porphyry are (105.9±1.1) Ma and (102.3±1.2) Ma, respectively, belonging to calc-alkaline to high-K calc-alkaline series. These rocks are enriched in light rare earth elements and large ion lithophile elements such as Rb and K, but depleted in P, Ti, Nb, Ta and other high field strength elements. The Ce4+/Ce3+ values of zircons in granodiorite porphyry range from 165 to 656 ℃ (mean 322 ℃), with Ti saturation temperatures ranging from 605 to 715 ℃ (mean 658 ℃). On the other hand, the Ce4+/Ce3+ values of zircons in granite porphyry range from 359 to 868 (mean 480), with Ti saturation temperatures ranging from 606 to 680 ℃ (mean 646 ℃). Zircon εHf (t) values of these two rocks are 6.9-8.1 and 5.6-8.2, respectively. The δ34S value of pyrite ranges from -7.8‰ to -0.2‰ with an average of -3.5‰, and the common Pb isotope ratios are 206Pb/204Pb=18.160-18.399, 207Pb/204Pb=15.538-15.590, and 208Pb/204Pb=38.135-38.340. The R/Ra values of fluid inclusions in pyrite range from 0.75 to 1.23. Comprehensive characteristics suggest that the mineralization-related magma is derived from the evolution of homologous crystalline magma, and the of magma emplacement occurred during the Early Cretaceous. The initial magma may have originated from the partial melting of the young lower crust material during the subduction of the Paleo-Pacific plate, with some mantle-derived materials mixed in during the formation process. The ore-forming fluid comes from deep magma and exhibits the characteristics of a mixed crust-mantle source (with the crust being the main source and mantle fluid accounting for 8.23% to 13.62%). The higher oxygen fugidity and lower magmatic crystallization temperature of granite porphyry provide favorable conditions for gold accumulation and migration, thus facilitating large-scale gold mineralization.

 N2O is an important greenhouse gas, and farmland is considered to be one of the major sources of its emission. Exploring the reduction potential of N2O not only provides theoretical and technical support for farmland carbon emission reduction measures, but also provides a scientific basis for the realization of China's "double carbon" goal. In order to reduce N2O emissions in Jilin Province, the denitrification-decomposition (DNDC) model was used for point simulation, result verification and sensitivity analysis based on the data of greenhouse gas emissions from Jilin University Functional Agriculture Base (Hunchun). At the same time, the N2O emissions were simulated from 1991 to 2020 under the conditions of corn planting in Jilin Province, its temporal and spatial characteristics were obtained, and the optimization measures for increasing corn production and reducing N2O emissions were proposed. The result shows that the DNDC model was effective in the simulation of N2O emissions from farmland in Jilin Province. Among all the  factors,  nitrogen fertilizer application rate had the greatest influence on N2O emission, followed by  organic fertilizer application rate, soil organic carbon content  also had a certain infulence on N2O emission,while temperature, rainfall and  proportion of straw returning to field had little influcence on N2O emission. As a result of corn cultivation, N2O emissions are highest in the west, middle in the central region and lowest in the east. In order to reasonably control N2O emissions from farmland in Jilin Province, different field management should be carried out in different regions, and the optimal nitrogen application rates are 400, 330 and 480 kg/hm2 with the best base to topdressing application ratios of 7∶3, 9∶1 and 9∶1 in the west, central and east, respectively. The proportion of straw returned to the field has little effect on N2O emissions. While maintaining production, reducing the mass fraction of organic carbon can decrease N2O emissions from agricultural land.

 In order to explore the drainage status and the associated impact of loess in engineering practice, strain increment ratio by triaxial test are used to investigate the shear behavior of saturated remolded loess subjected to five drainage conditions, which are no drainage condition, forced water absorption condition, free drainage condition, forced drainage condition, and partial drainage condition. The results show that, the shear behavior of saturated remolded loess are closely related to drainage conditions. In no drainage condition and forced water absorption condition, the loess samples exhibit strain softening behavior. Taken broadly, under the condition of forced water absorption, the shear expansion of the sample is forcibly exerted. In free drainage condition and forced drainage condition, the loess samples exhibit a strain hardening behavior, and the dilatancy is inhibited in the imposed drained samples. In partial drainage condition, the loess samples show a strain softening behavior or a transition state from strain softening to hardening, in which it is not only related to the strain increment ratio, but also to the void ratio. The closer the strain increment ratio is to 0, the more obvious the softening degree of the sample is. While the smaller the pore ratio of the sample, the more obvious the shear expansion trend is in the initial shear stage, and the higher the peak strength and residual strength of the sample. Besides, based on the asymptotic state equation and the stress-dilatancy relationship, the asymptotic behavior of loess and the associated dilatancy are analyzed. The result shows that the stress ratio of remolded loess at asymptotic state is negatively correlated with the sample dilatancy. 

To further explore the geothermal storage resources in the Chengning uplift region of Shandong, it is necessary to make reasonable and sustainable development plans to provide scientific basis for further exploration and comprehensive development of geothermal resources . In this paper, the geological survey data and field test results are used to analyze the genesis of geothermal fluids. Using the thermal storage method and comprehensive index method to estimate the resource quantity and analyze the development prospects of the Cambrian-Ordovician karst geothermal resources and provide scientific basis for further exploration. The result shows that the available geothermal resources of Cambrian-Ordovician karst heat reservoir are 1.97×1019 J, equivalent to 6.72×108 t of standard coal; The annual recoverable amount of geothermal fluid is 29 777.40×104 m3 /a. The area available  for development is 1 538.29 km2, accounting for 86.18% of the total karst geothermal area. The Cambrian-Ordovician karst geothermal reservoirs in the area have great potential for development and utilization, so that exploration efforts should be increased to promote the development and utilization process.

The salt lake area of the Qaidam basin has abundant reserves of underground brine resources, the regional brine reservoirs have the characteristics of lower porosity, strong heterogeneity and anisotropy, and large differences in regional brine-rich properties. In order to accurately detect the underground brine enrichment area and determine variation range of salt rock distribution density difference of the Mahai Salt Lake, it is aimed at the unique salt rock medium, the high salinity of intercrystalline brine, and the coexistence of various brine storage modes such as pore brine storage and structural brine control in the salt lake area of the Qaidam basin. The multi-scale and multi-geophysical exploration method including pumping test, high-precision gravity method, audio magnetotelluric method and high-resolution seismic method were used to detect the distribution density difference variation range of salt rock layer, the electrical change of crystalline salt layer and brine-rich stratum. The pumping test shows that the brine enrichment area composed of Wells K12, K13, K14 etc. has a water yield of 37 297 m3/d in brine rich area Ⅰ. The brine enrichment area composed of T1, K1, K4 etc. has a water yield of 35 736 m3/d in brine rich area Ⅱ. Based on pumping test and integration technology of various geophysical exploration information, two underground brine enrichment areas that can be sustainably and stably exploitated were determined, stratigraphic structure and geological structure in the Mahai Salt Lake were delineated and established.

In order to investigate the effect of sepiolite addition on the construction workability and permeability of soil-bentonite slurry barrier wall, as well as the retardance of heavy metal cation contamination in groundwater, natural sepiolite was used to modify the soil-bentonite slurry barrier wall. Lead was used as a representative contaminant and slump， permeability and adsorption tests were carried out. The results show that the addition of sepiolite not has much impact on the construction workability of the soil-bentonite-sepiolite barrier material. Increasing the sepiolite dosage from 0 to 30% increases the optimum water content of the barrier material by only 1% when meeting the target slump requirement. Sepiolite has little effect on the permeability performance of the slurry barrier material in the experimental dosage range, and the permeability coefficients of the materials are less than 10-7 cm/s, which can meet the engineering requirements. The adsorption of Pb2+ by the soil-bentonite-sepiolite material is an adsorption process dominated by chemical adsorption, and the adsorption amount of Pb2+ by the material was 89.73, 112.52, 140.85, 183.40 mg/g in the order of 0, 5%, 10%, and 20% of sepiolite doping, and the adsorption amount was reduced when the temperature was decreased. Under the corrosion of Pb2+, the permeability coefficient of the soil-bentonite-sepiolite barrier material gradually increases, but the presence of sepiolite can delay the corrosion of Pb2+ to the barrier material. Changes in pH and lead mass concentration of the exudate indicate that the soil-bentonite-sepiolite barrier material still acts as a blocking material during the experimental time.

 Ammonia nitrogen is one of the main inorganic pollutants in groundwater, which mainly comes from agricultural, industrialy and domestic pollution. Excessive ammonia nitrogen will endanger human health. Temporal and spatial distribution of ammonia nitrogen is affected by factors such as meteorology, hydrology, hydrogeology, and land use type, so groundwater ammonia nitrogen analysis based on limited sampling points will generate great uncertainty. In this study, firstly, the Songhua River basin in the Sanjiang Plain was taken as an example, and soil organic matter mass fraction, soil total nitrogen mass fraction, soil cation exchange capacity (CEC), soil pH value, groundwater depth, thickness of clay layer in vadose zone and land use type were selected as potential influencing factors, a machine learning model for fitting ammonia nitrogen concentration was established. Secondly, significant influencing factors were identified using the shapley additive explanations (SHAP) method of interpreting machine learning models. Finally, a machine learning prediction model was established according to the significant influencing factors, and the data of groundwater ammonia nitrogen in the study area was interpolated. And the temporal and spatial variation of ammonia nitrogen was analyzed. The results showed that groundwater depth, land use type, CEC and soil organic matter mass fraction were the main influencing factors of groundwater ammonia nitrogen in this area. The area of groundwater ammonia nitrogen in the Ⅰ-Ⅲ water quality level showed an increasing trend. The proportion of area increased from 31% to 87%. And the area of Ⅳ-Ⅴ water quality showed a decreasing trend. The proportion of area decreased from 69% to 13%. The overall water quality was improved from 2011 to 2018.

Traditional lithology identification methods are based mainly on drilling cores, curves, and rock images. These identification methods have high requirements on geological conditions and cannot meet real-time identification while drilling. For this reason, a new intelligent recognition method of lithology classification based on acoustic signals is proposed. This method first solves the problem of data sparseness through data enhancement technology based on the audio data obtained by the collision between the collected drill bit and the rock formation. Then, the deep learning model based on CGRU （CNN+GRU,convolutional neural networks+gated recurrent unit）  is used to conduct deep learning and training on the collected three types of rock audio data. Finally, to improve the model’s recognition ability in a complex background, the attention model is introduced for optimization. The attention model can realize key learning of lithology information in a complex environment and improve the recognition performance of the model. The experimental results show that, compared with GMM (Gaussian mixture model)-SVM (support vector machine), CNN and CGRU models, the accuracy of CGRU-AttGRU (attention mechanism model+GRU) hybrid model is about 81.17%, which is 13.31%, 9.99% and 5.93% higher than GMM-SVM, CNN and CGRU models respectively.

 Volcanic facies model in the basin is an important basis for reservoir distribution and identification. There are still some problems including stratigraphic unit inconsistency, unsystematic drilling, and large differences between basins. It is necessary to establish a system of facies models of basic stratigraphic units. This paper summarizes the definitions of facies, lithofacies and volcanic facies. Volcanic facies are divided into three classification schemes, which are for geological mapping and mineral survey in field, modern volcanoes and volcanic rocks in basin. It is considered that it is preferancial to apply the modern volcanic research results to guide the study of volcanic facies in the basin. The deposited units of volcanostratigraphy highlight the elements of rock fabric and geometric shape, and the volcanic facies division scheme of 5 facies, 15 subfacies and 44 microfacies is summarized. The eruptive facies is divided into pyroclastic flow, base surge, volcaniclastic apron, and volcaniclastic diatreme subfacies. The effusive facies is divided into subaerial lava flow, subaqueous lava flow, and subaerial eruption-subaqueous emplacement lava flow subfacies. The extrusive facies is divided into subaerial lava dome, underwater lava dome, and early subaqueous-late subaerial lava dome subfacies. The volcano-sedimentary facies is divided into lahar and debris avalanche subfacies. The subvolcanic facies is divided into dikes, laccolith and sill/lopolith subfacies. The characteristics of the fabric and structure of each microfacies are pointed out. Lava with different chemical compositions can form the same subfacies or microfacies. For example, rhyolite and basalt can both form the braided lava flow subfacies of the subaerial lava flow, while rhyolite, dacite, andesite, and basalt can all form the subaerial lava dome. With respect to the reservoir potential, the braided lava flow microfacies is better than the various microfacies of the subaerial lava dome. Therefore, the classification scheme in this paper can establish a detailed correlation between the subfacies/microfacies and the reservoir, and can be suitable for reservoir prediction and volcanic facies comparison in the basin.

 The study of shale lithofacies is the basic work of shale gas geological evaluation and layer selection. This paper takes the Wufeng Formation-Member 1 of Longmaxi Formation in Changning area of Sichuan basin as the research object. By using outcrop, drilling, and logging data, combined with rock and mineral, thin section, and geochemical data, the mineral composition, lithofacies characteristics, and their influence on gas content of shale are systematically studied, the favorable lithofacies are determined, and the spatial distribution characteristics of shale lithofacies in Changning area are characterized. The results show that there are five lithofacies in this area: Clay-siliceous mixed shale, mixed shale, siliceous shale, calcareous-siliceous mixed shale, and calcareous shale. Vertically, the volume fraction of carbonate minerals gradually decreases from bottom to top, and the integral number of clay minerals gradually increases. The lithofacies is a transition of calcareous siliceous shale-siliceous shale-clay-siliceous mixed shale. The subsidence center of the study area is located in the northeast of Changning area, and the lateral thickness of the siliceous shale lithofacies shows an increasing trend from southwest to northeast. The siliceous shale has the characteristics of high biogenic siliceous mass fraction, high w(TOC), high brittleness, and high pore structure parameters, so it has the best gas content. Although the clay minerals in the clay-siliceous mixed shale can generate secondary pores through diagenetic transformation, their plasticity is high, and the pores are difficult to preserve due to compaction. In addition, the higher plasticity leads to undeveloped shale fractures, which further reduces the physical properties of the reservoir, and the clay-siliceous mixed shale has poor gas-bearing properties.

Airborne gravity magnetic gradient and tensor gradient measurements can effectively reduce the impact of environmental noise, describe the distribution of geological bodies, and highlight shallow geological bodies with higher resolution. With the develpment of measurement equipment, it has been applied in oil, gas, and mineral resource exploration. This article systematically summarizes the research progress of airborne gravity (magnetic) multi-components gradient detection technology, providing a reference for subsequent related research. The progress development of equipment at home and abroad is summarized based on the research background of airborne gravity and magnetic multi-components gradient technology. The data processing process is introduced based on the characteristics of multi parameter gradient data in airborne gravity and magnetism. Obtained from the airborne gravity and magnetic multi-components gradients’resolution characteristics, we summarize the current high-resolution inversion and joint inversion methods for gravity and magnetic multi-parameter gradients. Derived from the application characteristics of airborne gravity and magnetic multi-components gradient detection technology in mineral，oil and gas resource exploration, the application prospects of this technology in deep resource exploration are analyzed, such as identifying underground structures, searching for mineral resources, and detecting small underground target bodies.

A typical vertebrate assemblage has been discovered in the Cretaceous Quantou Formation in Changchun area of Jilin Province. It is represented by eight main fossil vertebrate groups, including the basal Ornithopoda, Iguanodontia, Ceratopsia, Theropoda, Sauropoda, Crocodilia, Eutheria and dinosaur eggs. The basal ornithopod Changchunsaurus parvus is the most dominant taxon, with a large number of fossil bones. Herein, we define this assemblage as “Changchunsaurus Fauna”. In order to study the diversity of this fauna, the theropod dental materials in our collections have been studied in detail. The selected measurement data from the specimens are plotted on a two-dimensional scatter diagram for analysis, and the morphological comparison and identification of the specimens are carried out in combination with the features of the teeth. The study found that there are at least four different types of theropods in the fauna, respectively allosaurs, dromaeosaurs, tyrannosaurs, and a large indeterminate theropod. Among them, dromaeosaurs are reported for the first time in the Mesozoic strata in Songliao basin. The high diversity of theropods in Changchunsaurus Fauna indicates that this assemblage should be a vertebrate community with a rich species composition.

 The geological processes and their interactions in the earth not only control the formation and evolution of global geological patterns, but also control the formation of geothermal resources and the occurrence of seismic activities. Through systematic investigation and summary, this paper systematically discusses the symbiotic deep driving mechanism of geothermal resources and seismic activities. Firstly, the background of the formation of global high-temperature geothermal and large/ultra-large seismic zones are summarized. Most high-temperature geothermal and large earthquakes overlap in spatial distribution and are formed  at  active plate margins, while medium-low-temperature geothermal is often formed in  plates and accompanied by seismic activities. Secondly, the deep driving factors of the symbiosis between geothermal resources and seismic activity are summarized, and it is found that fluid and fault structure play a crucial role in the release of heat energy and earthquake, and are the main controlling factors of geothermal resources and seismic activity in deep depth. Thirdly , the results of deep geophysical exploration of geothermal resources and seismic activity are summarized, indicating that the homology and causality relationship between geothermal and earthquake can be revealed by magnetotelluric methods, and geothermal and earthquake are derived from the exchange of deep matter and energy. Finally, the research methods and development direction of the deep driving mechanism of the co-occurrence of geothermal resources and seismic activities are prospected.

Ultra-heavy oil is a strategic material for industry and national defense. Steam-assisted gravity drainage (SAGD) leakage is a critical problem to be solved urgently in the most advanced ultra-heavy oil development mode. The monitoring and characterization of the SAGD leakage channel are the most important. The three-dimensional electrical resistivity tomography is used to characterize the SAGD leakage channel. According to the resistivity change of oil and water in the leakage  channel after logging calibration, the resistivity of the leakage channel in the study area is lower than 3 Ω· m. The leakage channel is nearly north-south, narrow at the bottom, and wide at the top. Based on the geological and seismic data, it is considered that the SAGD leakage channel is a “cavity-crack” mode. There was no  leakage in the early stage of SAGD development. With the formation of the SAGD steam chamber, it gradually communicated with the upper stratum fracture zone during upward expansion, and the steam channeled up to the ground vertically along the fracture.

 In order to conduct a systematic study of thick dark mudstone and coal seams in the deep Late Paleozoic strata at the eastern foot of Taihang Mountains, Henan Province, taking the Late Paleozoic strata as the research object and using methods of sedimentology and sequence stratigraphy, the high resolution stratigraphic correlation and sedimentary facies division of the Upper Paleozoic Taiyuan Formation, Shanxi Formation and Xiashihezi Formation in the study area were carried out. A total of 5 rock types, 16 lithofacies types, 5 sedimentary facies and 10 sedimentary subfacies are identified. Three sequence boundaries and two key system tract boundaries were further identified, and 10 third-order sequences and corresponding system tracts were divided. Therefore, the sequence stratigraphic framework of coal measures strata in this area were established, the lithofacies paleogeographic characteristics in the isochronous stratigraphic framework were established, and its sedimentary evolution history was analyzed. It further defines the horizontal and vertical spatial distribution, evolution characteristics and the response relationship with the structure of each group of sedimentary facies, revealed that the sedimentation has a control relationship with all kinds of reservoirs, and established two typical coal accumulation models. On this basis, combined with gas logging data, the water and gas barriers and gas bearing systems are identified and divided within the sequence stratigraphic framework, the vertical distribution characteristics of coal seam gas content and the sealing characteristics of sequence structure on gas bearing systems are revealed, and the division of gas bearing systems of Late Paleozoic Coal measures are completed. There are two gas-bearing systems about Class I in sequence 2 of Taiyuan Formation and sequence 4 of Shanxi Formation.

China is not only a major consumer of cobalt resources but also a big importer of cobalt resources. Influenced by the new energy electric vehicle industry, cobalt ore resources have attracted more and more attention in recent years. In order to scientifically evaluate the potential of cobalt resources, guide the deployment of prospecting and exploration, and improve the guarantee capacity of cobalt resources in China, we carried out cobalt resource potential evaluation of cobalt resources in 9 key provinces (regions) from 2019 to 2021. Based on the perspective of the distribution and geological characteristics of cobalt deposits, the types of cobalt deposits predicted for prospecting in China are determined, including: weathering type, chemical deposit type, sandstone type and submarine hydrothermal-sedimentary type, all of which related to the sedimentary geological processes; marine and continental volcanic rock type that related to the volcanic geological processes; magmatic type, skarn type (contact metasomatic type), hydrothermal vein type and porphyry type, all of which associated with intrusive magmatism; sedimentary metamorphic type and a small number of metamorphic core complexes type that related to the metamorphism. And the metallogenic geological bodies related to various types of cobalt deposits are also sorted out and summarized. By analyzing the geological characteristics and spatio-temporal distribution of cobalt deposits in China, and synthesizing prediction elements such as geological, geophysical, geochemical, and remote sensing information, a prospecting prediction model was established, prospecting potential areas were delineated, and resource reserves were estimated. The results show that the cobalt deposits in China include six main prospecting prediction types: weathering crust nickel-cobalt deposit, hydrothermal-sedimentary copper-cobalt deposit, marine volcanic rock copper-cobalt deposit, marine volcanic rock massive sulfide copper-zinc cobalt deposit, magmatic copper-nickel cobalt deposit and hydrothermal veined cobalt deposit; 416 cobalt ores were delineated,  64 prospecting potential areas were delineated, 99 prospecting targets were optimized, and further exploration suggestions were put forward. A total of 453 000 t of cobalt resources have been identified in 9 key provinces (regions), and the estimated cobalt resources are about 420 million t.

In order to remove a large amount of methylene blue in water, copper alginate (CA), a good biocompatibility material, was used as the carrier to prepare laccase and biochar encapsulated copper alginate spheres (Lac-BCA) to remove methylene blue. The loading characteristics and stability of the laccase were also investigated. The experimental results showed that the Lac-BCA had a wider operating range of pH (3-7) and temperature (10-80 ℃) compared with the free laccase. The relative activity of Lac-BCA could still be 79.4% when stored at 4 ℃ for 15 d. The Lac-BCA could remove 100.0% methylene blue (15 mg/L) after 8 h, and 93.4% methylene blue could still be removed after five times of reuse. Moreover, due to the addition of highly adsorbent biochar, the removal efficiency of Lac-BCA on pollutants was increased from 46% to 100% compared with CA. 

 Seismic exploration technology has the characteristics of large penetration depth and high resolution and is an essential geophysical technical means to achieve the goal of exploring deep mineral resources in China. Compared with non-seismic geophysical exploration methods, seismic exploration methods provide intuitive and straightforward structural imaging, providing powerful guidance for identifying magma migration channels and finding favorable mineralization spaces. At the same time, it can also explore hidden ore bodies in-depth and find mineralization parent materials. It thus can provide strong technical support for developing and utilizing deep mineral resources. This paper reviews the technological development of active source and passive source seismic exploration methods for metal deposits, respectively, and points out the technical advantages and progress of active and passive source joint exploration methods. Multi-source joint seismic exploration method and technology based on active and passive source data fusion, seismic data processing and interpretation method and technology based on scattering theory, high-precision signal-to-noise separation technology, and metal mine seismic exploration method and technology based on artificial intelligence are the key and potential methods to solve the problems of high-precision and high-resolution detection of deep metal mineral resources.

In order to compare the effects of different water-rock interactions on the damage and deterioration of filled jointed rock. The longitudinal wave velocity test, static uniaxial compression test and dynamic impact test are carried out on the filled jointed rock under the conditions of dry-wet cycle and continuous immersion. The effects of two different water-rock interactions on the wave velocity value, static and dynamic compressive strength，energy dissipation characteristics of filled jointed rocks are analyzed. Furthermore, the differences are compared in the degradation effects of mechanical parameters of filled jointed rock under different states (dry and water containing) after dry-wet cycle. The results show that, when the number of water-rock interactions is less than 10, the wave velocity of the rock sample under dry-wet cycle is significantly lower than that under continuous immersion. Howerver, with the increase of the water-rock interaction times, the difference in wave velocity values between the two cases is constantly narrowing. With the increase of the number of water-rock interactions, the static compressive strength, dynamic compressive strength and energy dissipation rate of the filled jointed rock decrease. Under 20 dry-wet cycles and continuous immersion, the static compressive strength of filled jointed rock decreased by 27.16% and 18.94%, the dynamic compressive strength decreased by 23.33% and 21.76%, and the energy dissipation rate decreased by 74.29% and 59.71%, respectively. It can be seen that the damage and deterioration of the filled jointed rock caused by the dry-wet cycles is greater than that caused by continuous immersion. In addition, the static compressive strength of the dry state rock sample is higher than that of the water-containing state rock sample after the action of dry-wet cycle, while the dynamic compressive strength of the dry state rock sample is lower than that of the water-containing state rock sample.

Pore structure is an important feature of oil shale, which directly affects the storage and transport of shale oil and gas. Therefore, studying the evolution of pore structure is of great significance to guide the in-situ exploitation of oil shale. In this paper, taking Balikun oil shale as the research object, based on thermogravimetric (TG), low-temperature nitrogen adsorption (LTNA) and mercury intrusion porosimetry (MIP) tests, combined with LTNA-MIP joint accurate characterization methods, to reveal the law of pyrolysis weight loss and pore development characteristics of Balikun oil shale during heating, and study the evolution process and mechanism of pore structure. The results show that the thermal weight of Xinjiang oil shale can be divided into low temperature slow weight loss section (20-360  ℃), medium temperature rapid weight loss section (360-500  ℃), and high temperature slow weight loss section (500-600  ℃). The internal pore types of Balikun oil shale are complex, and during the heating process, the micro and small pores evolve from slit type to conduit shape. The medium and large holes are always mainly inkbottle-shaped. The inkbottle-shaped pores developed intensively in the two temperature ranges of 300-400  ℃ and 500-600  ℃, and the effective pores developed in large quantities at 400-500  ℃. Native macropores dominated the low-temperature section, and the pore structure changed little under the combined influence of free water vapor pressure, mineral thermal expansion, and asphaltene softening. The concentrated pyrolysis of organic matter in the middle temperature section produces a pore expansion effect, the pore volume is significantly increased, and the pore type is mainly mesoporous. The expansion pressure is generated by the water loss of clay minerals and the phase change of quartz in the high temperature section, and the large pores and middle pores are further expanded.

 Applying the microtremer H/V method in urban areas faces many complex artificial noises. The microtremer data with a large number of noise needs to be denoised and extracted. In this paper, a   multiple weighted HVSR method based on XGBoost (extreme gradient boosting) is proposed to solve the problems that the existing methods are difficult to deal with the microtremer data with considerable interference and the signal extraction process is cumbersome. Firstly, the amplitude and frequency of the microtremer data are analyzed.  Amplitude-weighted spectral ratio, frequency-weighted spectral ratio, and multiple weighted spectral ratio are established. Then, the denoised HVSR curve is calculated by the XGBoost method. The proposed method is compared with the STA/LTA (short-time average/long-time average) method  to analyze the actual high-noise data, the results show that the proposed  method is better than the STA/LTA method for high-noise data extraction. 

 High-precision, high-resolution global seafloor topography models are critical foundational datasets for studying the Earth’s shape and interior structure. They are significant in multiple domains, including seafloor plate movement research, early tsunami monitoring, deep-sea resource exploration, underwater marine construction projects, ensuring maritime safety, and delineating marine territorial boundaries. The extensive and profound realms of the oceans present a formidable challenge for meticulously mapping the seafloor topography. However, satellite altimetry, with its global coverage, high precision, high resolution, and the ability to conduct regular observations of ocean dynamics, has emerged as the primary method for obtaining global bathymetric data. This paper provides an overview of the current state and recent developments in recovering bathymetry from satellite altimetry-derived data. It encompasses fundamental principles, major modes, and missions in satellite altimetry, marine gravity field inversion, methods for seafloor topography inversion, and seafloor topography model products. Additionally, the paper provides insights into the trends and prospects for constructing high-precision, dynamic global seafloor topography models.

Spring water is the important drinking water source for the village of Tuguanpu to the Da’an Town on the west side of the Hanzhong basin. The Study on the hydrochemical characteristics and genetic mechanism is of great significance to guide the development and protection of local water resources. In this study, 13 spring water samples were collected for water quality analysis. Mathematical statistics, Piper trigram, Gibbs diagram, saturation index method  and major ion ratios were used to comprehensively analyze the hydrochemical characteristics and genetic mechanism of the spring water in the study area. The results show that the spring water in the mountainous area on the west side of Hanzhong basin is weakly alkaline and low salinity water. In the hydrochemical composition, the cation is dominated by Ca2+ and Mg2+, while the anion is dominated by HCO3-. The main hydrochemical type of the spring water is HCO3-Ca·Mg，which is mainly controlled by the weathering of rocks. The CO2(g) in all water samples is not saturated and could be redissolved in groundwater. The dolomite and calcite of most spring water are in an unsaturated state, and the dissolution of them can still occur. The calcite and dolomite of Taixingya spring (S06), Jinjiakan spring (S07), Shuimogou spring (S08) and Chenjiaying spring (S11), and the calcite of Nangoumen spring (S12) have been oversaturated and are about to precipitate. Human activities slightly influence on the hydrochemistry of spring water. The ions in the spring water samples in the study area are mainly from the dissolution of carbonate rocks, and partly from the dissolution of silicate rocks.

To solve the freight ropeway path planning in the mountainous region, we proposed a comprehensive method of construction site selection and path planning of freight ropeway. The calculation and analysis methods were studied to process the geographic information data, select the loading and unloading position, screen and optimize the trestle position, and estimate construction quantity. The ropeway cost analysis formula was proposed based on the main influencing factors of ropeway construction, which provides a basis for ropeway path sequencing and analysis. The ropeway paths of three iron towers in typical areas were planned, and 110, 17, and 32 ropeway paths that meet the requirements were obtained, respectively. The average calculation time was 2.34 h, much lower than the 1-2 days of the manual path planning method. It can be seen that the proposed method can effectively shorten the path-planning cycle of material transportation.

Based on the sporopollen analysis of the strata in the 21.47-38.26 m section of ZK004 borehole in the Lishu fault depression, Songliao basin, and combined with the quantitative analysis results of oxide samples, this stratum is divided into two sporopollen assemblages from bottom to top, of which the ZK004-Ⅰ assemblage is dominated by Classopollis-Cedripites-Schizaeoisporites-Callistopollenites-Borealipollis, reflecting the transition from semi-humid   tropical-subtropical  climate to  humid subtropical climate; the ZK004-Ⅱ assemblage is dominated by Cedripites-Rugubivesiculites-Schizaeoisporites-Deltoidospora-Cyathidites-Borealipollis, reflecting the transition from  humid subtropical climate to semi-humid subtropical climate, which generally displays semi-humid northern subtropical climate, providing new evidence for the recovery of the paleoclimate and paleovegetation of the second member of Nenjiang Formation in the Late Cretaceous.

In order to quantitatively characterize the complexity of shale pore structures of Longmaxi Formation in Zhaotong national shale gas demonstration zone, Yunnan Province and its influence on shale gas, 24 pieces of shales collected from Longmaxi Formation were tested for TOC mass fraction, whole rock mineral composition and low-temperature nitrogen adsorption. And their influence on fractal dimension of shale pores was analyzed and discussed from two aspects of shale pore structures and mineral composition. The results show that there is a strong heterogeneity in pore development among different sub-layers in Member 1 of Longmaxi Formation in Zhaotong area, with the highest content of organic matter in the Layer 1, with a “three-stage” variation of decreasing-increasing-decreasing in the longitudinal direction. Shale pores are segmented, with fractal dimension D2 ranging from 2.699 4 to 2.912 4, with an average of 2.826 5 and fractal dimension D1 ranging from 2.617 4 to 2.719 4. The pore structures are complex and the fractal dimension is highest in the Layer 1 and gradually decreases upwards. The correlation between fractal dimension of shale with pore structure parameters and geological factors shows that TOC mass fraction and quartz volume fraction control the development of micropores, provide the main specific surface area, and have a good positive correlation with fractal dimension, which is conducive to the occurrence of shale gas, with higher total gas content and adsorbed gas ratio; The volume fraction of clay minerals and dolomite mainly controls the development of mesopores and macropores, provides the main pore volume, and has a negative correlation with fractal dimension. The combination of hydrocarbon generation, reservoir and development factors suggests that Layer 1 and Layer 3 are beneficial to shale gas retention due to their high TOC content, large fractal dimension and strong brittleness, making them become favorable horizons for shale gas development.

The impregnated diamond bit is a micro-cutting edge formed by exposing diamond in the matrix, and realizes the drilling of broken rock by crushing and grinding the rocks under the action of drilling pressure and torque. It can be widely used in hard formation and complex formation drilling. However, conventional diamond drill bits have problems such as low drilling speed, slow footage and high costs in hard formations. Firstly, rock samples, which were sampled in different depths form holes adjacent to the borehole S2Z-45 in GanQing  tunnel, were taken for testing and analysis of their hardness, mineral composition, and drillability. It was determined that most of rock layers were mainly diorite, and the rock’s drillability level was eight. Then, according to the geological characteristics of Ganqing tunnel, the matrix hardness and bottom lip shape of impregnated diamond were optimized. The influencing factors of the performance of impregnated diamond bit was analyzed by field tests. The experimental results showed that the impregnated diamond bit had the best performance when its matrix hardness was HRC 15-20, a diamond particle size was 40-50 mesh, the volume fraction of diamond was 20%, and a bottom lip with a ring groove sharp tooth shape. It has a lifespan of 321 m and a drilling speed of approximately 1.17 m/h. Under the same diamond parameters, the hob type impregnated diamond bit with a matrix hardness of HRC 10-15 had advantages in drilling speed, which the drilling speed of the drill bit could reach 1.44 m/h. The sharp tooth bottom lip surface of the ring groove and high matrix hardness helped to improve the life of the drill bit, while the rolling tooth bottom lip surface and low matrix hardness were beneficial for improving drilling efficiency, but the life of the drill bit was relatively low.

In the forced regressive system at the top of the Cambrian Zhangxia Formation in the Zhucaoying section of Qinhuangdao, Hebei Province, a set of leiolitic bioherms with a thickness of tens of meters were intensively developed, indicating that these leiolitic bioherms formed in shallow sea and high energy environment. Field investigation and microscopic observation, the formation mechanism and sedimentary environment of leiolitic bioherms are analyzed.The results show that the leiolitic bioherms  dense and homogeneous massive micritic limestone,  obvious macro fabric and directly the lower stromatolite bioherms.Under the microscope, the leiolite is composed of dense micrite and a small amount of sparry. The dense micrite contains a variety of calcified cyanobacteria sheath fossils, including Hedstroemia, Epiphyton, Renalcis,   and Girvanella. The results showed that the leiolite was formed by the complex metabolism of microbes and  in-situ. More specifically, oolith and dolomite crystals, indicating that the microtexture related to the calcification of globular microbial film and the selective expression of dolomite in the process of leiolite production under eutrophic conditions. There are not many related examples of leiolite since its, therefore the leiolitic bioherms in Zhangxia Formation of Qinhuangdao provide a typical example for understanding the formation mechanism and depositional environment of leiolite.

 The qualitative and quantitative characterization of the microscopic pore structure of the reservoir can benefit the efficient development of the reservoir in the later stage. In this study, the microscopic pore structure of Chang 4+5 ultra-low permeable reservoir was characterized in  Baibao area of Wuqi oilfield by using blue-dye thin section， SEM， high pressure mercury penetration. A local pore structure classification standard of the study area was established. Based on the experimental results, a real sandstone model is built up to evaluate the quality of the pore structure by the oil-water two-phase seepage experiment, and the existence types and causes of the micro residual oil in different pore structures are analyzed through the microscopic visualization of the oil-water displacement experiment. The results show that the combination type of class Ⅰ pore structure is intergranular pore-dissolved pore, oil and water two-phase seepage characteristics are the best, after water flooding, the micro residual oil mainly exists in the form of small contiguous clusters, oil displacement efficiency is 35%; Type Ⅱ pore structure is dissolved pore-residual intergranular pore, oil-water two-phase seepage characteristics is similar to class Ⅰ, water storage capacity and water flooding effect are the best, oil displacement efficiency is 43%, after water flooding, the micro-residual oil mainly exists in cluster and ring form; Class Ⅲ pore structure combination type is intercrystalline pore-dissolved pore, it has the worst physical properties, oil and water have the worst seepage characteristics, oil displacement efficiency is only 21%, after water flooding, the micro residual oil exists in the form of contiguous clusters. The diagenesis and the pore filling content in the study area mainly affect the pore structure development, thus affecting the microscopic residual oil distribution of different pore structures after water flooding.

 The Tenth International Conference on Gas Hydrates (ICGH10) was held in Singapore on July 9-14, 2023, with over 700 attendees, hosted by the National University of Singapore. ICGH10 received 538 abstracts, including 292 orals and 246 posters. ICGH10 summarized the research progress of gas hydrate in the past six years. This paper reviewed three aspects of them including energy exploration and development, flow assurance and hydrate application technology. As a clean and low-carbon energy source, natural gas hydrate has made many breakthroughs in basic theory and field production engineering, but there is still a certain distance from commercial development and utilization; To achieve efficient transportation of oil and gas pipelines, flow assurance technologies related to hydrate blockage have been widely studied. Many environment-friendly hydrate kinetic and thermodynamic inhibitors have been developed. In addition, hydrate technology is gradually moving from experimental research to commercial application in carbon sequestration, water treatment, and gas storage and transportation. This paper summarized the main content of ICGH10, aiming to introduce the latest international research progresses of gas hydrates.

The Sanhetun gold deposit in Heilongjiang Province is located at the southwest end of the Nenjiang-Heihe tectonic melangite gold metallogenic belt. Due to the thick Quaternary overburden and insufficient deep geophysical work, the breakthrough of the deep prospecting and the research of metallogenic model are restricted. In this study, the two-dimensional electrical structure of the study area was obtained by the two-dimensional data inversion of the audio geomagnetic long profile (about 8.5 km) across the deposit using the nonlinear conjugate gradient method. The results show that the 100 m shallow layer of the Sanhetun gold deposit has the characteristics of low resistivity. It reflects the shallow Cretaceous sand-mudstone and Quaternary weathering in this area. The continuous distribution of low resistance layers and the underlying high resistance anomalies in the northwest side of the section indicates the Cretaceous volcanic rocks and Carboniferous intrusive rocks. The high and low resistance transition zones under the section reveal the deep distribution characteristics of ductile shear zones and faults. These are important ore guiding and storage structures. In this paper, the metallogenic model of the Sanhetun gold deposit is established based on the regional geological data. In the Early-Middle Jurassic tectonic extensional period, the ore-forming fluid migrated upward along the fault and ductile shear zone, and then leached the gold elements from the Late Carboniferous intrusive rocks，which contributed to the first phase of mineralization in the study area. In the Early Cretaceous, the study area was again in an extensional and pull-apart setting, and the gold elements carried by the deep magmatic eruptions were transported along the newly formed and reactivated ductile shear zones and basin margin fractures toward the edge of the Sanhetun volcanic basin with the magmatic hydrothermal fluids,and gradually precipitated and  superimposed on the top of the earlier mineralization phase with the temperature decrease in the later period.

 

How to mitigate and eliminate the impact of debris flow on bridge pier is crucial to the safety of bridges. Taking the three-pile unit with trefoil-shaped distribution as the protective structures, a design principle for the size of this structures is proposed considering factors such as the characteristics of debris flow movement and the width of bridge piers. Firstly, an optimal arrangement of piles is obtained by simulating the impacts of block stone on different types of pile group structures. Then the impact of the debris flow with block stone on the bridge pier under pile structure was analyzed by using SPH-FEM method. The results show that the impact force of large stones and debris flow slurry on bridge piers is 3 843 kN, which is much greater than the impact force of debris flow slurry on bridge piers without protection, which is 1 840 kN, and the impact force of debris flow slurry on bridge piers with protection, which is 1 452 kN. The pile layout with a column spacing of 3.0 m and a row spacing of 1.0 m is the most stable. And after the protective structure was set up, the peak impact force of debris flow slurry, peak stress and peak displacement at the pier bottom whent=8.0 s were reduced by about 21.1%, 79.0% and 29.3%, respectively. Therefore the pile group structure has a significant protective effect on bridge piers impacted from debris flow.

 Coal mining has resulted in large areas of goaf and numerous abandoned mines. There are a large amount of coalbed methane resources in these abandoned mines. Different from conventional coalbed methane resources, the exploration and development of coalbed methane resources in abandoned mines are affected by the distribution of open areas, overburden, surrounding rock conditions, development of fissure zones, and conditions of the roof and floor of coal seams, coal mining methods, groundwater in goaves, etc., and geophysical exploration technology can provide technical support for developing coalbed methane in abandoned mines. This article provides an overview of coal geology in Shanxi and explores the factors contributing to the collapse and water accumulation in goaves. It also examines surrounding rocks and goafs' seismic wave, electrical, induced polarization, and radioactive radon anomalies characteristics. Furthermore, the article introduces various detection methods such as seismic, direct current, controlled source audio-frequency magnetotelluric, transient electromagnetic, induced polarization, radioactive prospecting, microtremor exploration, aviation, and semi-aviation transient electromagnetic methods. It is pointed out that developing and researching new geophysical techniques, establishing a multi-method, multi-dimensional, and multi-space comprehensive goaf detection system, making full use of geophysical big data, and in-depth exploration of artificial intelligence inversion technology can provide valuable information for coalbed methane resources in abandoned mines in my country. It is providing technical support for exploration and development.

The northern continental slope of the South China Sea is a large-scale submarine slope that extends in a belt-like configuration from the southeastern waters of Hainan Island to the southwestern waters of Taiwan Island. Several canyons and numerous steep slopes are located at this area. Due to the complex geological structure and earthquake-prone nature of the area, various geo-hazards such as landslides are active. In particular, due to the large topographic relief and frequently seismic activity, earthquake-induced landslides often occur in the region. So it is important to scientifically assess the seismic stability of large submarine landslides. In this study, a three-dimensional numerical model was developed using Scoops3D and GIS technology to investigate the seismic stability of typical steep slope groups located at canyons in the northern continental slope of the South China Sea. The results show that ：Most of the canyon profiles in the study area are in the shape of “U”, and it is inferred that the canyons are type Ⅱ submarine canyon system. Strong seismic action can substantially weaken the stability of submarine slopes located at canyons, in which the regional minimum safety factors of steep slope groups in C1 canyon dramatically decreases to 0.50 while the horizontal seismic coefficient with the increase to 0.40. The seismic-induced destabilization range of the steep slope groups in the western canyon is significantly higher than that in the eastern region, and most of the landslides are concentrated in the valley walls on both sides near the crests of the peaks, while a considerable portion of the landslides are located at the eastern valley walls of the southern section in C1 and C2 canyons, with the overall distribution being a belt-like shape. 

 Large-scale outbreaks of Dendrolimus superans infestation have led to severe losses of forest ecosystems and economies. It is of great significance to identify the area of Dendrolimus superans infestation quickly and accurately. In this study, knowledge graph technology was used to screen the sensitive features related to forest pests, and a random forest model with three different data combinations was constructed by comprehensive use of multi-source data to identify the Dendrolimus superans infestation occurrence area in the study area by remote sensing. The results are as follows: 1) The knowledge graph can be constructed and screened according to the graph construction process. In this study, the characteristics of forest insect pests were established by remote sensing, and the characteristics of Dendrolimus superans infestation in Northeast China were screened by remote sensing. 2) The combination of knowledge graph and remote sensing technology can provide practical features for constructing the pest identification model; 3) Compared with a single data source, the identification effect of Dendrolimus superans infestation based on multi-source data is better. In this study, the overall accuracy and Kappa coefficient of Sentinel-1A, Sentinel-2A and topographic data were 92.78% and 0.876 6, respectively. 

In order to accelerate the exploration and development process of deep tight sandstone gas in the southern Songliao basin, the formation mechanism of tight sandstone reservoir and the main controlling factors of reservoir formation are studied. At present, the discovered deep tight gas can be divided into three types: Stable thick sandstone, sandstone-mudstone interbedding, and muddy wrapped sandstone according to the petrological characteristics of tight sandstone. The physical properties of the reservoir are generally poor, the main porosity is below 6%, and the main permeability is less than 0.10×10^-3 μm², which belong to ultra-low porosity and ultra-low permeability reservoir. Based on the mineral composition and microscopic characteristics of typical tight reservoirs, it is found that the formation of effective reservoirs of tight sandstone is mainly controlled by three factors: First, chlorite enclaves are developed in the early diagenetic stage, which effectively inhibit the occurrence of intergranular calcareous cementation and siliceous cementation during the middle and late diagenesis, and protect the original residual intergranular pores; Second, secondary pores are formed by the dissolution of volcanic rock debris; Third, hydrocarbon generation pressurization produces a large number of micro fractures, which improves the seepage characteristics of the reservoir. The controlling factors of tight sandstone gas reservoir formation  are summarized as followings, the sufficient gas source, the sandbody controlled by slope paleo-valley and fault, the reservoir controlled by secondary dissolution and microfracture, the enrichment controlled by fault activity and stable cap rock.

 Effective reservoir rocks and their genesis in a heterogeneous petroleum reservoir are a critical geological issue of deep exploration. The Lower Jurassic Sangonghe Formation in the Fukang sag, central Junggar basin has been used as a case study to examine the dynamic relationship between diagenetic evolution and oil chargeing in sandstones, and discuss effective reservoir rocks and their formation using an integrated approach of petrography, SEM, stable carbon and oxygen isotopes, and fluid inclusion analyses. The results show the sandstones in the Sangonghe Formation consist mainly of ductile lithic-rich, very fine-to fine-grained, and medium- to coarse-grained petrofacies. The two defined petrofacies are interbeded, and represent demonstrable differences in diagenetic evolution and oil charge. Ductile lithic-rich, very fine-to fine-grained sandstones had a limited diagenetic process in which compaction and neomorphism of easily deformed, clay-rich lithic grains predominated, resulting in a very rapid loss of porosity during burial. They have become relatively nonporous before the first oil arrival and have never been charged later. By contrast, diagenetic events in the relatively coarser-grained sandstones with less abundant ductile-lithic grains included dissolution and cementation as well as ductile compaction. At least two episodes of oil charge occurred. Diagenesis progressed alternately with oil emplacement. The nonreservoir, ductile lithic-rich, very fine-to fine-grained sandstones can constitute impermeable barrier interbeds embedded in permeable reservoir rocks, probably resulting in heterogeneous oil migration.

Echinoderms is one of the most primitive animal groups, and its evolutionary history is crucial for understanding the origin and early evolution of multicellular animals. In this paper, some echinoderm fossils, collected from the Meitan Formation in Wudang area of Guiyang, are identified as thecal plates of the Glyptocystitoida and Hemicosmitoida in the Rhombifera, belonging to Polycosmites and Macrocystella. We also conduct a study of the Ordovician paleogeographic distribution of the two superfamilies, and find that the presence of Polycosmites and Macrocystella in the Meitan Formation expands the biogeographic distribution of the two genera in Yangtze plate. At the same time, this discovery reveals the diversity of echinoderms in Wudang area, and provides new information on the evolutionary radiation of echinoderms during the Early Ordovician.

 Laser drilling has the advantages of high energy, high directivity, cleanliness, non-contact cutting drilling, etc. In the process of laser thermal melting through the ice, meltwater has a great impact on the laser penetration efficiency. In order to explore the influence of meltwater on laser penetration efficiency, CO2 laser with higher ice absorption efficiency was selected to conduct fixed-point penetration experiments on ice samples prepared by simulated polar ice cores under different irradiation angles and different laser power. The results show that when the negative incidence Angle is -90°--15°, the penetration velocity is 0.67-2.20 mm/s, which is only 21%-40% of the theoretical velocity, and the aperture reaches 3-5 times of the spot diameter. When the Angle of incidence is 15°-45°, the melt water is removed in time due to gravity, and the penetration velocity is 13.19-36.50 mm/s, which is 2.2-6.5 times of the theoretical velocity.

Based on the accumulation of previous research on deep strata and the progress of oil-gas prospecting in northern Songliao basin and its surrounding areas in recent years, this paper first introduced the characteristics of regional geology and geophysical fields, and then according to the features of the target stratum of deep strata, studied the structural and stratigraphic characteristics of the deep strata in the northwest Songliao basin by comprehensive geophysical prospecting methods such as broadband seismic and wide-field electromagnetic method. The petrophysical parameters of Songliao basin and its surrounding areas were sorted out, and the physical characteristics of strata with different formation ages were summarized, with emphasis on the analysis of the physical differences between the Upper Paleozoic and its upper and lower strata. It is concluded that there are obvious differences in physical properties between the Permian and its overlying Meso-Cenozoic, the underlying strata and various types of rocks in this area, which is the precondition to study the distribution of the Upper Paleozoic by geophysical methods. On this basis, this paper expounds the progress of combined geophysical investigation of gravity, magnetism, electricity and seismic in the key target area. The quality of broadband seismic imaging for the deep strata is significantly improved compared with the previous seismic explorations, and we have obtained clearer geophysical information. According to the above geophysical information, several geological survey wells were deployed, and successively drilled into the argillaceous rocks with anomaly of gas logging in deep Permian. In addition, this paper also discussed the challenges faced by the deep hydrocarbon geological survey and the future research directions in the study of petrophysical properties and integrated geophysical prospecting methods.

Sipingshan gold deposit is located in the Wandashan epicontinental accretional terrane in eastern Heilongjiang, China. The ore bodies are mainly hosted in the Lower Cretaceous Sipingshan Formation, showing obvious two-stage mineralization. To further determine the mineralization and genesis of the deposit, this study analyzes its metallogenic geological characteristics, metallogenic chronology and source of metallogenic materials. The samples from the ore-related granite porphyry have relatively high SiO₂ (70.07%-72.93%) and （K₂O+Na₂O）(7.17%-8.42%), which belong to A-type granite. The ore-bearing siliceous rocks are characterized by Al/(Fe+Al+Mn)<0.32, Fe/Ti>20, (Fe+Mn)/Ti >20, Fe₂O₃ (0.18%-1.79%), FeO(0.17%-0.96%), MnO (0.03%-0.12%), TiO₂ (0.03%-0.04%), Al₂O₃ (0.30%-2.79%), (K₂O+Na₂O)(0.07%-1.76%), indicating that Sipingshan gold deposit is formed in a hydrothermal depositional environment related to magmatic activity in the tectonic setting of active continental margins. The granite porphyry is identified as the parent rock of Sipingshan gold deposit, with a U-Pb zircon age of (113.5±0.7) Ma. The H(δD=-182.3‰--84.0‰),O(δ¹⁸O_V-SMOW=6.5‰-14.3‰), and S(δ³⁴S=-12.4‰-29.7‰) isotopic results indicate that the ore-forming fluid is mainly atmospheric precipitation, and the ore-forming materials have stratigraphically dominated multi-source features. To sum up, Sipingshan gold deposit is a hydrothermal sedimentary deposit formed in the Late Yanshanian active continental margin tectonic background. The continuous subduction of the Pacific plate caused large-scale delamination, resulting in a transition from extrusion to extension. This granite porphyry magma formed at this period migrated to the shallow crustal magma chamber to heat the overlying stratum, and formed a temperature and pressure gradient zone in the shallow crust, which prompted the atmospheric precipitation on the surface to enter the stratum along the fissures to form a fluid circulation system, and continuously extract Au elements in the formation to form ore-bearing fluids. In the early stage,when the pressure drived the ore-bearing fluids to be ejected from the surface, it encountered the surface water and cooled rapidly, and the ore-forming materials precipitated rapidly, forming the  layered ore-bearing siliceous rocks and siliceous cemented conglomerates, which formed layered orebodies by metasomatism of the underlying rhyolite porphyry. This process was weakened with the thermal power provided by the magma chamber dying down. In the later stage, the ore-bearing fluids stayed in the fissure channels or penetrated into the fissures of the early consolidated ore-bearing layer, then precipitated to form vein-like and reticulated-vein-like ore bodies.

Based on the chain transfer process of seawater intrusion hazard, this study established a risk assessment index system of coastal region in Laizhou City according to the risk of disaster causing factors, vulnerability of disaster bearing body, disaster loss and disaster prevention and mitigation capability and ascertained the weight of each index by combined method of the analytic hierarchy process (AHP) and the entropy weight method (EWM) based on the minimum information entropy, ultimately the total risk value and corresponding ranking were obtained by the comprehensive weighted evaluation method to figure the hazard degree and influencing factors of seawater intrusion in Laizhou City. The calculation result of the total risk index showed that Chenggang Road had the highest risk, with a value of 5.76, and Jincang Street had the lowest risk, with a value of 4.03. According to the total risk value, research zone was divided into the highest risk, high risk and lower risk zone. Pearson correlation test and comparison of risk value of indexes presented that groundwater exploitation intensity with correlation index of 0.917 is the control index of regional seawater intrusion risk assessment and the key factor to prevent seawater intrusion disaster.
Key words: seawater intrusion; AHP; EWM; risk evaluation; Laizhou City

Gangdong fault is a critical reservoir-controlling fault in the north of Qikou sag. In order to study the oil and gas distribution of Sha-1 Lower Submember in the Gangdong fault of Qikou sag, there are two cases of oil and gas transporting forms recognized: The distribution position of the entire oil and gas transporting form from the Gangdong fault to the Sha-1 Lower Submember sand body was predicted based on the overlapping of the following three key factors, the transport site of the Gangdong fault in Sha-1 Lower Submember, the regional mudstone cap sealing site of Sha-1 Middle Submember, and the connected sandbody distribution site of Sha-1 Lower Submember. The distribution position of the partial oil and gas transporting form from the Gangdong fault to the Sha-1 Lower Submember sand body was predicted based on the overlapping of the following four key factors, the transport location of Gangdong fault within Sha-1 Lower Submember, the unsealed location of regional mudstone cap of Sha-1 Middle Submember, the distribution location of connected sandbodies of Sha-1 Lower Submember, and the overlying regional mudstone cover of Minghuazhen Formation. The results show that: The entire oil and gas transporting form is mainly distributed in the east and west, while partial oil and gas transporting form is mainly distributed in the middle and locally in the east. The distribution position of the entire and partial oil and gas transporting form controls the distribution of the entire oil and gas fault in Sha-1 Lower Submember of Gangdong fault.

 In colleges and universities with large population and density, scientific planning of earthquake evacuation paths in earthquake-prone areas is of great significance to the life and property safety of teachers and students. Based on the extraction of spatial distribution information and relevant survey  of Chaoyang Campus, Jilin University,    this study realizes the scientific planning of the evacuation paths of  daytime and nighttime simulated scenarios in the study area using  location allocation (LA) model  and  Dijkstra optimal path algorithm, combined with service domain analysis and  optimal path analysis. The results show that playgrounds, outdoor basketball courts, open meadows, and some large parking lots can be used as backup safety zones in the earthquake evacuation plan of universities. LA model and Dijkstra algorithm can meet the requirements of earthquake evacuation planning when evacuation directions do not conflict, and the capacity of the safety zone is large. In view of  the unbalanced space distribution of earthquake evacuation safety places in campus, some suggestions are put forward to improve the earthquake escape system in colleges and universities, such as balanced distribution of open space, increasing the facilities of earthquake evacuation, and strengthening the skills of earthquake evacuation.

 Since the 20th century, the frequency of geological disasters appearing in the form of disaster chains has significantly increased. Currently, there are few researches on the evolution process and impact scope of the disaster chain. In this paper, the evolution process of the disaster chain was illustrated taking the high-level remote landslide debris flow disaster chain in Tiejiangwan, Hongya County, Sichuan Province on April 5, 2021 as an example. The initiation source is high-level collapse, and a large number of falling rock blocks impact and load the rock and soil mass on the lower slope to form a landslide, and then the avalanche debris flow material of the landslide develops into a debris flow towards the Shuangxi River under the influence of rainfall. RAMMS software was used to numerically simulate and analyze the movement process of the debris flow, and its impact range was delineated under different rainfall frequency. The results show that the impact scope covers some scattered farmers in the upstream of Shuangxi Village under the frequency of rainfall in 20 a, the impact area covers the densely populated area of Shuangxi Village under the frequency of 50 a, and the impact area will continue to develop downstream and extend to the residential area of Laozhaohe under the frequency of 100 a. During the disaster chain, the maximum rainfall in the vicinity of Tiejiangwan close to the frequency of 10 a rainfall. It was found that the simulated results of the 10 year return period was consistent with the actual impact range, indicating that the simulation results were reliable.

Qinghai Province is located in the Northeastern Qinghai-Tibet Plateau, where the Qinling-Qilian-Kunlun and the northern Qiangtang-Sanjiang orogens are amalgamated. It has experienced the formation and development of the basement, spreading, subduction, closure and collision of the Proto-Paleo-Neo Tethys Ocean, and plateau uplift process. In the long-term geological tectonic evolution, different metallogenic processes occur and are accompanied by a series of ore deposits in a specific time and space. Based on the latest mineral exploration achievements obtained since the implementation of the “Qinghai 358 Geological Exploration Engineering” and “Strategic Action of Prospecting Breakthrough”, 137 kinds of minerals, 895 deposits and 4 597 ore (chemical) points have been analyzed. A systematic summary and study of the tectonic environment, metallogenic geological conditions, metallogenic characteristics, metallogenic processes, genetic types, metallogenic ages and metallogenic regularities, using the metallogenic series theory proposed by Chen Yuchuan et al., 14 metallogenic series groups, 46 metallogenic series, 76 metallogenic sub-series and 131 ore deposit types of major deposits in Qinghai Province were divided. Finally, 11 metallogenic series groups, 25 metallogenic series, 44 metallogenic sub-series and 63 typical ore deposit types with the most prospecting prospects are proposed, and a brief summary and analysis are made according to metallogenic zones.

 The dispersed soil has very poor water stability and is prone to damage such as pipe surges, caves, gullies and other damage. The seasonal frozen soil may enhance its dispersion during the freeze-thaw cycle in seasonal freezing area. In order to study the effect of different calcium agents on soil dispersion improvement and the influence of freeze-thaw cycle on the improvement effect, first，two kinds of calcium ionizers, calcium oxide and calcium chloride, were used to improve the dispersed soil in the western area of Jilin, and the optimum mixing dosage was determined to carry out the freeze-thaw cycle test. Then, the influence of freeze-thaw cycle on the improvement of soil dispersion was discussed by dispersive identification test, unconfined compressive strength test and microstructure test respectively. The test results showed that the improvement effect of calcium chloride on soil dispersion in western Jilin was better than that of calcium oxide, and the optimum mixing dosage of calcium oxide for improving dispersed soil was 1.6%, while the optimum mixing dosage of calcium chloride for improving dispersed soil only was 0.4%. The calcium chloride improved soil of 0.4% was used in freeze-thaw cycle test, it was still non-dispersive soil after different times of freeze-thaw cycle, and its unconfined compressive strength was a significant decline in the number of freeze-thaw cycles of 0-5 times. However, the decline tendency slowed down and the compressive strength was basically at 60 kPa after more than ten freeze-thaw cycles. By observing the scanning electron microscope images of the improved soil with 0.4% calcium chloride in different times of freeze-thaw cycles, it is assumed that the state of the cracks and pores of the improved soil tend to be stable after 10 times of freeze-thaw cycles. The above test results show that calcium chloride can be used as a good ameliorator to improve the soil dispersion in seasonal freezing zone.

 The bender element is a commonly used method for testing small strain dynamic parameters of soil. However, when using bender element for testing, the waveform, frequency, peak value, and sample size can have a certain impact on the determination of the travel time of the wave in soil. At present, the influence of input wave on the travel time of output signal is mostly studid from the aspect of the frequency of input wave, but the the impact of the input wave peak and input waveform on the output signal is soldom studied. Therefore, in this paper the small strain dynamic parameters of dry Fujian standard sand were studied by bender element, and the effects of parameters such as input frequency, input wave peak, input waveform, relative density, and confining pressure on the constrained modulus, shear modulus, and Poisson’s ratio were analyzed. The results show that the input frequency has a significant effect on the travel time of S-wave(shear wave), and basically has no effect on P-wave(primary wave). The magnitude of the input wave peak has no effect on the travel time of S-wave or P-wave discrimination. The input waveform has a significant effect on the travel time of the S-wave or P-wave. The constrained modulus, shear modulus, and Poisson’s ratio of soil vary exponentially with the increase of confining pressure and pore ratio. Based on the small strain modulus prediction model proposed by Hardin, a three-dimensional model formula considering the coupling effect of confining pressure and pore ratio was fitted, which can provide certain reference for the estimation of constrained modulus, shear modulus, and Poisson’s ratio in practical engineering.

Hongshuihe iron deposit in the Eastern Kunlun orogenic belt, Qinghai Province, is a middle-sized one in which iron formations are localized within the phyllite of the Langyashan Formation. The ore types are mainly massive magnetite quartzite type, and minor banded type, which was generally considered as sedimentary metamorphic iron deposit by predecessors. Based on previous researches, this paper presents new data from major, rare earth and trace elements as well as Fe isotope analyses for massive iron ores in the iron formations of the Hongshuihe iron deposit. New Fe isotope results yield variableδ56FeIRMM-014values mostly ranging from 0.97‰to1.97‰, with one exception, showing similar Fe isotope compositions with typical Neoproterozoic iron formations of the world. The results of major, rare earth and trace elements show that these ores have high SiO₂+Fe₂O₃ contents (78.56%-98.06%)and very low Al/(Al+Fe+Mn) ratios of 0.00-0.06, indicating that they are typical chemical sedimentary rocks. The total rare-earth-element contents (∑REE) vary from 16.49×10^-6 to 80.89×10^-6, with no obvious Ce abnormally, and light-rare-earth-element are slightly depleted, which shows a similar characteristic to the Neoproterozoic iron-bearing structures. Based on the comprehensive comparison of Fe isotope compositions, depositional ages and geochemical characteristics of iron formations in the Hongshuihe iron deposit, we can conclude that there was a passive continental margin tectonic environment of the Qaidam-East Kunbei block in the Neoproterozoic during iron formation, and iron and other ore-forming materials were predominantly derived from marine hydrothermal fluids. The marine hydrothermal fluids rich in Fe²+ upwelled and gradually evolved into low-temperature hydrothermal fluids which then mixed with oxygen-bearing surface seawater in a sub-oxidized condition. Finally, Fe²+ was partially oxidized and formed ferric hydroxides, which subsequently deposited on the continental slope and eventually formed iron formations. The genetic type of the Hongshuihe iron deposit can be classified as the Neoproterozoic Rapitan-type iron formations.

[WTHZ]Key words:[WTBZ] 

 Due to the influence of equipment and environmental factors, the signals collected by ground-penetrating radar (GPR) are vulnerable to varying degrees of noise interference. Traditional variational mode decomposition (VMD) suppresses noise by searching for the optimal solution of variational modes to separate the components with different center frequencies. However, the selection of optimal mode number is challenging and subjective, resulting in the reconstructed signals being affected by different degrees of oscillation. To solve these problems, we proposed a combined denoising method based on the adaptive VMD and singular spectrum analysis (SSA). Firstly, the energy loss ratio is defined to facilitate the adaptive selection of the optimal mode number, and the Pearson correlation coefficient method is employed to extract the valid signal. Secondly, to solve the problem of the low-frequency oscillation phenomenon in VMD, SSA is further used to perform secondary filtering to improve the signal-to-noise ratio (RSN). The effectiveness of the proposed method is verified by the synthetic wavelet experiment, numerical simulation experiment, and field experiment. In the synthetic wavelet experiment, the SNR of VMD-SSA processing is improved maximum by 13.587 8 dB over the ensemble empirical mode decomposition (EEMD) and the traditional VMD methods; in the numerical simulation experiment, the SNR of the processed B-scan using the VMD-SSA method is improved by 3.765 9 dB and 2.655 7 dB respectively compared with the EEMD and traditional VMD methods; in addition, the background noise and the random noise are also properly suppressed in the field data processing. The proposed method not only solves the oscillation problem but also highlights the features of the abnormal signals more effectively.

The observation of seismic resistivity plays an important role in earthquake monitoring and prediction. Due to the acceleration of urbanization, the observation environment of surface resistivity stations is seriously disturbed. In order to suppress environmental interference, geoelectric scientists have carried out underground geo-resistivity observation and research since the 1980s. In this paper, the research on the development of underground geo-resistivity observation in China is reviewed. The suppression ability of stray current and metal pipelines, the relationship between annual variation of underground geo-resistivity caused by seasonal variation and observation device, and the seismic reflection efficiency are evaluated and analyzed. The advantages of underground geo-resistivity observation are described: it can suppress the interferences caused by abnormal bodies and seasonal changes, weaken the influence of surface stray current obviously, reduce the annual variation range of resistivity effectively, and solve the problem of increasingly serious surface environmental interferences. With the development of seismic monitoring and prediction from empirical prediction to physical prediction, more and more attention will be paid to the establishment and application of underground geo-resistivity observation system.

In order to study the geochemical characteristics and enrichment patterns of the organic-rich black fine-grained rock series in the Middle Ordovician Yanxi Formation in the central and southern Hunan， samples from Ningyuan Mianhuaping (MHP)， Shuangpai Hejiadong (HJD)， Quanzhou Shazitang (SZT) and other sections are collected and analyzed for TOC, major elements,  trace elements and rare earth elements. The results show that the organic geochemical index of the Middle Ordovician Yanxi Formation in the central and southern Hunan is good, and the SiO2 content is high, which belongs to the high-quality source rock;The organic matter abundance of the black shale is relatively high， the average w（TOC）is 2.12%， which is generally higher than 2%， and the brittle mineral content is more than 50%， so it has good gas generating capacity. The large number of siliceous layers developed in the Yanxi Formation are mainly of sedimentary origin. The redox parameter U/Th,V/(V+Ni) and other indicators indicate that the overall water body is an oxygen-limited reductive environment， and the productivity of the Yanxi Formation was high； The terrigenous material input， redox environment， relative changes of sea level, and paleoproductivity affect the enrichment of organic matter together. The enrichment of organic matter in the shale of Yanxi Formation is mainly controlled by the anoxic environment, which belongs to the enrichment model of “deep-water retention basins”.

In order to reveal the provenance and geological significance of the Paleogene in Sunwu-Jiayin basin, this paper studies the detrital zircon dating and geochemical characteristics of samples from Paleogene Wuyun and Sunwu Formations. The age peaks of 72 measuring points of detrital zircons in Wuyun Formation are 57, 97, 188, 262, 380, 496, and 1 854 Ma, and the age peaks of 64 measuring points of detrital zircons in Sunwu Formation are 52, 65, 92, 181, 220, 472, 1 884, and 2 318 Ma, indicating that the provenance of Wuyun Formation and Sunwu Formation is complex and diverse. The contents of MgO, Al2O3, CaO, K2O and Fe2O3 in the samples are relatively low. The chemical alteration index CIA value ranges from 64.30 to 81.72, and the composition variation index ICV value ranges from 0.44 to 0.70. Th/Sc values are positively correlated with Zr/SC values. The total amount of rare earth elements (∑REE) changes from 97.44×10-6 to 154.87×10-6 and 85.65×10-6 to 315.62×10-6, respectively. La/Yb ratios vary from 10.94 to12.84 and 13.26 to 20.74. Combined with the characteristics of major, trace and rare earth elements and the age peaks of detrital zircon, it is concluded that the Paleogene sources are the Paleoproterozoic geological body in the eastern margin of Songnen-Zhangguangcai range Massif and the felsic igneous rocks produced by magmatic events in various times. The tectonic background of the source area is active continental margin and continental island arc. There are apparent differences between Paleogene and Upper Cretaceous provenance in the basin. Combined with the characteristics of regional tectonic evolution, we speculated that it was caused by the Pacific plate retreat or drawback and subducted direction changes in the process of Pacific plate subducting to the East Asian continent. 

Hongqiling magmatic Cu-Ni sulfide deposit is located in the southeastern margin of the Central Asian orogenic belt (CAOB). In this paper, the multi-degree vertical derivative and 2.5-D interactive inversion technique are used to predict the mineralization of the hidden orebodies in the deep (500-1 000 m) Cu-Ni deposit, and to study the ore-bearing properties of the mafic-ultramafic rocks (such as #1, #3 and new #3 plutons). The results show that the high-precision gravity anomaly can effectively determine the spatial distribution of deep hidden orebodies by carrying out data processing on the upper edge of different heights and the vertical first-order derivative, and the 2.5-D interactive inversion technique can be used to detect the weak anomaly caused by deep orebodies. It is speculated that there are 5 blind vein-shaped orebodies in the #3 pluton in the study area with a burial depth of 700-1 100 m. After drilling verification, 32 259 t of Ni ore was successfully discovered (the average grade of ore is 0.36%), of which No. 2 ore body is the thickest ore body, the ore penetration depth is 700-1 100 m, the average Ni ore grade is 0.39%, and the reserves are up to 27 433 t.

Because of the advantages of surface nuclear magnetic resonance, such as direct, quantitative and unique inversion, it is widely used in hydrological environment investigation, early warning of disaster water source, and other fields. However, in practical applications, the nanovolt level SNMR signals is often submerged in the environmental noise and difficult to break down, which makes the result inaccurate. In this paper, a method for extracting SNMR signal envelopes based on local mean decomposition (LMD) is proposed. First, the real and imaginary envelopes of the noisy SNMR signal are decomposed sequentially from high frequency to low frequency. Then the noise interferences in the signal are removed, and the required signal components are extracted. Finally, the effective real and imaginary components are synthesized to obtain the target SNMR signal envelope. The results indicate that the fitting error of the initial amplitude of the SNMR signal envelope extracted by LMD  is within ±4.17%, and the error of the average transverse relaxation time is within±5.63%. The signal-to-noise ratio is improved by 30.3-37.2 dB.

 In order to explore the mechanism of the effect of temperature changes on the permeability of clayey soil at 5-30 ℃, while considering the fluid properties induced by temperature changes and the influence of soil deformation on the hydraulic conductivity, and improve the application range and accuracy of the model, in this paper combination of laboratory experiments and theoretical models were used to study. Then, based on the experimental data of variable temperature seepage, a relationship equation between soil strain and medium void ratio was constructed. Finally, further modifications were made to the modified model of the Kozeny Carman model (REN model). The results show that in the common temperature range of 5-30 ℃ in groundwater, the deformation of soil caused by temperature changes has a significant impact on the hydraulic conductivity of clayey soil. The maximum calculation error of hydraulic conductivity can reach 40% under considering only the variation of fluid viscosity with temperature and ignoring the effect of clayey soil deformation. The modified model has better performance compared to existing hydraulic conductivity models. Through the analysis of the modified hydraulic conductivity model, it was found that the main controlling factor for the change in hydraulic conductivity is fluid viscosity when the temperature is in the range of 5-20 ℃, and has a small impact on the hydraulic conductivity with a degree of less than 10%. When the temperature is in the range of 20-30 ℃, the contribution rate of hydraulic conductivity induced by soil deoformation caused by temperature increase, and an maximum impact on the hydraulic conductivity exceeding 40%.

Controlled-source electromagnetic method (CSEM) signals are often contaminated by strong human noise, and the resolution of CSEM exploration is greatly affected. In order to improve the quality of CSEM data, in this paper, a new intelligent data processing method is proposed based on support vector machine (SVM) algorithm. Firstly, the baseline-drift noise is removed by complementary ensemble empirical mode decomposition (CEEMD) algorithm, and then the data is classified by SVM to select high-quality signals. In order to validate the proposed method, a targeted experiment was conducted using simulated noise and measured high-quality data, and then the method was applied to the measured data by the wide-field electromagnetic method (WFEM). The results show that the recognition accuracy of SVM is greater than 92.00%. After the treatment of the proposed method, the apparent resistivity changes from jumping shape to continuous and smooth.

The seismoelectric effect is an important representation of the seismoelectric transformation phenomenon in underground porous media. It can be used to detect underground oil, gas, and other pore fluids. In the numerical simulation of seismoelectric effect, traditionally the quasi-static approximation is adopted for the theoretical simulation of electromagnetic response. However, the quasi-static approximation ignores the influence of seismic shear waves, leading to significant errors in the simulation of electromagnetic field, and may not satisfy the premise of applying quasi-static in some cases. In order to accurately reveal the mechanism of seismoelectric effect, a finite difference method in frequency domain based on Maxwell’s full equation is proposed to simulate the frequency electromagnetic response of seismoelectric  effects, and the seismoelectric characteristics of the layered and anomalous conductivity models in an elastic homogeneous medium are analyzed and discussed. The results show that the reflection and transmission of electromagnetic wave field can be characterized by the Maxwell’s full equation numerical simulation more accurately at the interface of different media, and the abnormal position can be more accurately identified. This provides a new idea for improving the resolution of deep underground oil and gas detection.

The topography of geophysical exploration areas is often undulating and complex, and the traditional long-offset transient electromagnetic method (LOTEM) 3D forward modeling generally does not consider the influence of topography. However, the topographic factors seriously affect the reasonable interpretation of LOTEM data. The 3D forward modeling of LOTEM under real topography by the unstructured edge finite element method is developed in this study. Firstly, the 3D modeling software Blender is used to accurately build a complex geoelectric model, and the unstructured tetrahedral mesh is used to finely describe the real topography. Secondly, the dipole discrete field source processing technique is used to separate the long conductor source into several electric dipoles, and the second-order backward-Euler scheme is used to complete the time discretization. In this way, fast and high precision 3D forward modeling of LOTEM can be realized. The transient electromagnetic field response characteristics of the complex geological model under real topography conditions are simulated on the premise of guaranteed computational accuracy. The results demonstrate that due to the influence of topography, the LOTEM electromagnetic field response is severely “distorted”, which can weaken or even completely “cover up” the transient electromagnetic field response of underground targets, and it seriously affects the effective detection of underground targets.

To study the influence of thermal physical parameters of rock mass on seepage heat transfer results, based on discrete element 3DEC software, the heat-flow coupling numerical model of granite with parallel double fractures was established, and the model was verified by comparing with the analytical solution. Based on the numerical model, the distribution characteristics of the rock mass temperature field under different parameters were studied. Combined with the orthogonal experiment method, the sensitivity analysis of the parameters affecting the heat-fluid coupling was carried out. The results showed that the maximum error between the numerical solution and the analytical solution was 3.45%, which indicated that the model is accurate and reliable in studying the heat transfer problem of water flow in fractures. After the model runs for 24 h, the temperature of the inlet and outlet of the fracture is different under different schemes, which indicates that different parameters have different effects on the seepage heat transfer. Along the flow direction of fracture fluid, the sensitivity of model temperature to test parameters tends to decrease. The range values of specific heat capacity of rock mass, fluid velocity and fracture opening at the fracture inlet (point B) are 10.25, 13.80 and 13.25 respectively. The specific heat capacity of rock mass, fluid velocity and fracture opening were the main factors affecting the temperature of heat flow coupled model. The extreme difference values of rock mass heat conductivity and fluid rock heat transfer coefficient were 6.53 and 4.66, respectively. The rock mass heat conductivity and fluid rock heat transfer coefficient had little influence on the model temperature.

Transient electromagnetic method(TEM) is a type of time-domain electromagnetic detection method, which is widely used in mineral resource exploration, coal mine, water and mud inrush investigation, karst investigation, and other issues. In conventional TEM data inversion，smoke-ring fast imaging and linear iterative inversion methods are used, which have the disadvantages of low accuracy, easy to fall into local minimum, and large calculation amount of sensitivity matrix. In this paper, a nonlinear optimization algorithm is proposed for transient electromagnetic data inversion, and the particle swarm optimization (PSO) algorithm and firefly algorithm are used for comparative analysis.  Typical three-layer and four-layer geoelectric models are established, and the convergence and anti-noise characteristics of the two methods are analyzed. The research results show that the PSO algorithm has high computational efficiency, however the data processing accuracy is low and the anti-noise ability is poor. The firefly algorithm has great advantages over the PSO algorithm in terms of noise resistance and data processing accuracy. We processed the measured data by using the two methods and compared the results, the above conclusions are verified.

 With the increasing requirements for large-depth and fine-structure detection of geological targets, the research on further improving the relative resolution of the controllable source electromagnetic method has gradually become a research hotspot. In order to improve the high-frequency signal-to-noise ratio, suppress human interference, increase the depth of exploration, we proposed high frequency power supply technology based on capacitor compensation, data acquisition and processing technology based on frequency optimization and digital filtering to suppress power frequency interference, and interpretation technology based on direct inversion of observed electromagnetic field. First, the capacitor network unit is connected to the power supply circuit, and by calculating distribution circuit inductance and selecting compensation branch，the closest resonant capacitance is combined to the theoretical value, so as to increase the sending current of sending signals at different frequencies by putting capacitors with different capacitance values in series for different frequencies of 1 000-10 000 Hz. Then, by optimizing the sampling rate and sampling length, and by digital filtering, the influence of 50 Hz power frequency and its harmonics on the observed data can be corrected. Finally, through extending the frequency of conventional CSAMT low frequency observations from 0.100 Hz to 0.025 Hz, the exploration depth can be improved by direct treating and inversing the observed electromagnetic field components. On this basis, the theoretical model of numerical simulation was established. The deep exploration tests of known geothermal fields were carried out in the disturbed area. The results show that the depth of CSEM can reach 3 000-5 000 m, which effectively enhances the exploration depth of the artificial source electromagnetic method.

Magnetic resonance sounding (MRS) is a geophysical method for directly detecting groundwater. It is widely used in water resources investigation and other fields, as it is quantitative, accurate, and efficient. The quality of MRS signal strongly affects the interpretation of magnetic resonance data. In this paper, the random noise suppression of MRS signal under strong environmental interference is studied. Based on the framework of convolutional neural networks (CNN), the nonlinear mapping relationship between the time spectrum of noise signal and the time spectrum of original noiseless signal is obtained by using the training method of supervised learning, so as to suppress the noise of magnetic resonance signal. The simulation results show that the signal-to-noise ratio of noisy MRS signal can be improved by more than 15 dB. The noise suppression effect of CNN is analyzed and compared with that of the time-frequency peak filtering (TFPF) method. The effectiveness and superiority of this method is proved by the noise suppression of the measured field data. 

The degree of salinization is serious in the south of Xinjiang Uygur Autonomous Region. Due to the frost heaving and salt heaving damage of saline soil foundation, the stability of channel slope in irrigation area is greatly damaged. A mathematical model of optimizing channels with quadratic parabolic cross section on saline soil was established using artificial atomic algorithm to avoid the problems of redundant calculation, large cumulative error and low precision by using iterative calculation method. The mathematical model used quadratic parabolic shape parameters as independent variables and was given channel bottom slope and roughness. According to the ratio coefficient between the optimal hydraulic section and the quadratic parabolic practical economic section of medium and small channels, the shape parameters were optimized by this algorithm to determine the practical economic section of the channel. The mathematical model was applied to Xiaosi branch canal in Tarim irrigation area of Xinjiang to verify the validity. Compared to the trial algorithm, this method was more suitable for the section optimization design of small and medium-sized channels. The calculated flow error was only 0.85% of the error of the trial algorithm. The results showed that the concrete quantity of parabola shaped optimization section was reduced by 3.34%.

Based on the composition of natural gas, stable carbon isotope, light hydrocarbons composition characteristics and geological background, the geochemical characteristics, genetic types and sources of natural gas in the Shahejie Formation of Niuju-Changtan sag were analyzed and discussed. The following research results were obtained. First, the natural gas is methane-dominant, and the content of heavy hydrocarbon is relatively high, mainly characterized by wet gas. The non-hydrocarbon gases are mainly N2 and CO2. Second, the δ13C1 value of natural gas is between －42.8‰ and －31.2‰, and the δ13C2 value is between －27.3‰ and －24.7‰. Carbon isotope reverse of natural gas is caused by the mixing of homologous different period gases. Third, organic matter types of gas source rock are mainly humic-prone and humic type. The δ13C-Ro relationship and the maturity-depth relationship curve were used to calibrate the maturity of natural gas. The natural gas in the middle and south of Niuju-Changtan sag is mature coal-type thermal degradation gas, which is derived from the source rocks in and Ess3, while the natural gas in the north is oil-coal pyrolysis gas, which is derived from the source rocks in Esz3 and Esx3.

Sulfur is an important non-metallic mineral and one of the dominant minerals in North China. North China is an important production area of pyrite and natural sulfur with abundant and concentrated sulfur resources. Based on the summary of resource endowment, deposit type, spatial and temporal characteristics, main ore controlling factors and metallogenic evolution, this paper comprehensively analyzes the main characteristics and metallogeny of sulfur deposits in North China. From the perspective of ore genesis, sulfur deposits are classified into five types, including sedimento-metamorphic type, sedimentary type, magmatic hydrothermal type, skarn type and natural sulfur type. There are 18 mineral prediction types based on mineral prediction factors, of which sedimento-metamorphic type, sedimentary type and magmatic hydrothermal type pyrite are the most developed. Sulfur deposits are mainly distributed in rift zone, uplift zone, arc-basin system, active continental margin, etc. The metallogenic age, type and scale of the deposits formed in different tectonic environments are different. According to their regularity, they can be divided into five metallogenic stages: Including Archean, Mesoproterozoic, Late Paleozoic, Mesozoic and Cenozoic. The sulfur mineralization has undergone multiple phases of tectonic evolutionary cycles. which are divided into volcanic eruption-sedimentation events during Neoarchean-Paleoproterozoic accretion and amalgamation of continental crust, exhalaive hydrothermal-sedimentary events during Neoproterozoic-Mesoproterozoic extensional rifting of North China craton, volcanic eruption-intrusion events during uplift of North China block and deposition of epicontinental basin in Late Paleozoic, tectono magmatic events during the superposition and transformation of the Paleo-Pacific tectoinc domain in Mesozoic, salt lake deposition during extension and thinning of intracontinental basin in Cenozoic. On the basis of the evaluation of mineral resource potential, 22 important sulfur prospecting areas are divided in North China, showing good metallogenic conditions and prospects.

The East Kunlun Metallogenic Belt (EKMB) is an important Au-Cu-Co-Ni-Fe-Pb-Zn and other polymetallic metallogenic belts in China. The discovery of the Xiarihamu super-large Ni deposit in the summer of 2011 made East Kunlun become an important Cu-Ni resource base in China. After years of exploration, great breakthroughs have been made in the prospecting of Cu-Ni deposits in the EKMB, and a number of mafic-ultramafic complexes with great prospecting potential have been discovered successively, such as Shitoukengde, Akechukesai, Langmuri and Gayahe intrusions. Based on the researches in recent years, the metallogenic regularity and characteristics of the magmatic Cu-Ni sulfide deposits in the EKMB are preliminarily summarized, and the prospecting target for the next step is pointed out. Main understandings are as follows: At least four stages of Cu-Ni-Co-(PGE) metallogenesis with different intensities occurred in the EKMB, i.e., Cambrian-Ordovician (535-445 Ma), Silurian-Devonian (440-394 Ma), Permian-Early Triassic (271-239 Ma) and Late Triassic (233-208 Ma), among which the Silurian-Devonian has the largest number of intrusions and the highest mineralization rate, and produces the largest number and scale of ore deposits, while other stages have less number of intrusions, smaller scale and weaker mineralization. Different from other ore-forming plutons scattered throughout the EKMB, the Silurian-Devonian intrusions are strictly distributed in the north of the Central Kunlun fault, and most of them occur in the Central Kunlun belt with significant clustering. They have significant metallogenic specialization with the most important ore-bearing rocks belonging to ultramafic rocks enriching in chrysolite and orthopyroxene. The primary magma is derived from the large proportion of partial melting of the asthenospheric mantle, and crustal contamination is one of the most important key factors of sulfide saturation. The Silurian-Devonian intrusions have the greatest prospecting potential, mainly distributed in the Central Kunlun belt, which is the main prospecting target and area for future prospecting and exploration. The intrusions of other stages have less prospecting potential, but the Cu-(PGE) ore-bearing of Cambrian-Ordovician intrusions still need to be further evaluated.

 The basic geological research of Akchukesai area in the western Segment of the East Kunlun orogenic belt is weak. The granite gneiss in this area was designated as the Jinshuikou Group by predecessors. In field work, it was found that the Jinshuikou Group gneiss should be a granite gneiss intrusion. In order to determine the geochronology and petrogenesis of the intrusion， the rock geochemistry, zircon U-Pb geochronology and Hf isotope studies were carried out in this paper. The results show that: the lithology of the sample is gneissic biotite monzogranite, major element data show that the SiO₂ content is 74.44%-76.36%, Na₂O and K₂O contents are respectively 0.06%-0.07% and 3.89%-4.35%, Al₂O₃ content is 9.76%-10.95%, A/CNK is 0.92-1.09，TiO₂ and MnO contents are respectively 0.32%-0.38% and 0.10%-0.13%；CaO content is 2.70%-3.46%，Mg^# is 25.42-29.69；The rare earth elements of the samples are higher, ΣREE is 200.04×10^-6-215.30×10^-6, LREE/HREE is 6.94-7.88. Trace elements show the characteristics of enriched in Rb, U, Th, K and Nb, Ta, P, Ti, Sr showed“V”type depleted. The age of formation is Early Neoproterozoic ((966±3)Ma，MSWD=4.1), zricon in situε_Hf(t)=-3.38-3.14, Hf isotope two-stage model ages T_DM2 range from 2 033-1 625 Ma. Petrogeochemical and Hf isotopic results show that the gneissic biotite monzogranite is peraluminous-weak peraluminous high-K calc-alkaline I-Type granite. The magma source area should be dominated by new basaltic crust, with the addition of Paleoproterozoic silical-aluminum crust, which may be the partial melting of plagioamphibole and gneiss of  Paleoproterozoic Jinshuikou Group. The petrogeochemical characteristics show that the samples were formed under the tectonic background of subduction to collision transformation in the Early Neoproterozoic. Based on the comprehensive analysis of regional tectonic background, it is concluded that Early Neoproterozoic magmatism and tectonic activity are prevalent in the East Kunlun region, which responds to the global Rodinia supercontinent convergence event. The samples studied in this study are the concrete manifestation of the collision formation of Rodinia supercontinent convergence in the western segment of East Kunlun, this indicates that the region was transitioning from subduction to collision orogenic stage at  about 966 Ma.

In order to realize effective classification of low-permeability and tight sandstone reservoirs and clarify the classification boundary, and effectively guide the selection of reservoir development countermeasures, this paper used the methods of grey correlation, multivariate analysis, information superposition and cluster analysis to carry out comprehensive reservoir classification and determine the classification boundary. In this paper, firstly, based on grey correlation, the reservoir quality factor IRQ, main throat radius, movable fluid saturation, sorting coefficient and displacement pressure are selected as the main controlling factors for reservoir evaluation. Secondly，the comprehensive quantitative evaluation of the reservoir is completed by the information superposition of the multivariate analysis and the grey evaluation results, and K-means clustering method combined with probability distribution function is proposed and the boundary of each factor is clarified. Finally, a clustering method combined with probability distribution function is proposed. The results show that the average error between the calculated value of IRQ conversion model obtained from logging and experimental data and the measured value of core is 8.60%, which confirms the reliability of the model. The average errors of the optimized clustering algorithm and the single factor classification method are 13.57% and 19.63% respectively, and the former is more accurate. The rationality of the method is verified by the single well productivity: The daily oil production in stable production period of type Ⅰ well is above 7.48 t/d, that of type Ⅱ well is 4.37- 7.48 t/d, and that of type Ⅲ well is less than 4.37 t/d. 

In order to investigate the genesis of high quality reservoir, we compare the diagenesis characteristic and the genesis of tight sandstone within sequence stratigraphical framework based on sequence stratigraphical framework division in the Shahezi Formation by making full use of thin-section, SEM, physical properties, X-ray and trace elements analysis. We divide the Shahezi Formation into four 3rd-order sequences and fourteen system tracts. The distinguishing characteristic of diagenesis within the sequence framework is made up of sequence boundary and sequence unit. Cementation and dissolution are under the control of sequence boundaries. The cementation content and compaction strength in sandbody above the sequence boundary are greater than below. There are many more dissolutions in sandbody below the sequence boundary than above. Diagenetic events within different system tracts correspond to periodic evolution of formation fluid and medium environment. The diagenesis is mainly featured by chlorite and calcite cementation in LST, intense feldspar dissolution and illite cementation in TST, mechanical compaction and authigenic quartz in HST, feldspar and rock debris dissolution and kaolinite cementation in RST. The sedimentary environment differences in various positions within the sequence framework influence the sedimentary characteristics and control the physical fundament of diagenesis and primary porosity. Because of the periodic evolution of water properties and environment, the early diagenesis is differentiated in LST, TST, HST, and RST, which makes the sandbody in RST and TST the best reservoir for gas accumulation.

The Jiapigou gold metallogenic belt is one of the important gold concentration areas in the marginal-Pacific metallogenic belt. The Shajingou gold deposit is located in the southeast of Huadian City, Jilin Province, which is in the eastern part of the northern margin of the North China plate, the southern side of the JiHei orogenic belt and the central part of the Jiapigou gold metallogenic belt, with superior metallogenic geological conditions. A number of large, medium and small gold and silver deposits have been discovered in the exploration area and surrounding area, such as Erdaogou gold deposit, Miaoling gold deposit, Yunfeng lead-zinc deposit and Majiadian gold deposit in the northwestern area, Bajiazi gold deposit in the north area and Dayangcha gold deposit in the exploration area. With the same geological background as the above gold deposits, the Shajingou gold deposit has the geological conditions of producing large and medium-sized gold deposits. Based on the comprehensive study of geophysics, geochemistry and geology, it is concluded that the ore-bearing structures in study area are characterised by low resistance and high polarization. The development of low resistance areas often indicates the existence of fracture structures, and the medium and high resistance zones within the low resistance zones are striped and have more potential for mineralisation. The soil geochemical anomalies are Au-Ag-As-Cu-Hg-Sb and so on. The distribution of ore bodies in the northwest and northeast of study area is equidistant, the ore bodies are spatially correlated with the vein rocks, and the ore bodies are enriched in elements, and the multi-causal coupling of mineralisation is discussed. The next prospecting should be fault-controlled ore and magmatic intrusion system controlled ore.

The Triassic granites in the Lancang-Menghai area of western Yunnan belong to the southern part of the Lincang granite belt, which are distributed in a nearly north-south direction. The main lithology is biotite monzogranite with weathered crusts, which has favorable metallogenic conditions for ionic rare earth deposits. In order to understand the internal relationship between the Triassic granite and REE mineralization, the petrological and geochemical characteristics of the Triassic biotite monzogranite and its weathered crust have been studied. The medium-grained (medium-coarse) or porphyritic biotite monzogranite in the inner facies zone of Triassic granite is more favorable for mineralization than the fine-grained biotite monzogranite in the outer facies zone. Under the effect of weathering and leaching, rare earth elements in biotite monzogranite are separated from rare earth independent minerals or rare earth-containing accessory minerals and then adsorbed into the whole weathered regolith clay minerals for mineralization. The biotite monzogranite is characterised by high silicon, rich potassium and rich aluminum. The completely weathered layer is more aluminum-rich, while the contents of MgO, TFeO and CaO decrease, and the content of trace element Ce decreases significantly. The characteristics of other major elements, trace elements and rare earth elements inherit the characteristics of parent rocks. A comprehensive study shows that the Triassic biotite monzogranite in the study area has the basic condition for the mineralization of adsorbed rare earth deposits, and the contents of dissociable rare earth independent minerals and rare earth-containing accessory minerals are important factors for the formation of ionic rare earth deposits.

 The paleo-Pacific tectonic system controls the formation and evolution of the East Asian continental margin, but there is still controversy over the onset of the subduction of the paleo-Pacific plate and its detailed evolution process.  Shiren Village in Helong Lity is located in south Jilin Province, in the eastern part of the northern margin of the North China plate, which is a favorable area to study the evolution of the paleo-Pacific Ocean. This paper presents a synthesis study of zircon U-Pb geochronology, geochemistry and Hf isotopes on the granodiorites. The studied rocks yield an average zircon LA-ICP-MS U-Pb age of (173±1) Ma, suggesting a Middle Jurassic magmatic event. The rocks are characterizd by high Mg^#(65.23%-65.92%), abnormally high w (Sr)（(1 657-2 467)×10^-6）, and low w (Y)（(7.50-7.98)×10^-6） and w(HREE), very similar to the low Si adakite defined by Martin et al.(2005), reflecting that the initial magma is derived from the mantle wedge metasomatized by plate melting. The significance lies in the existence of very hot subduction in this area around 173 Ma, which may be caused by an oblique subduction or oceanic ridge subduction, and also means that the subduction direction of the paleo-Pacific plate towards Eurasia deflected or the subduction mode changed in the Early Middle Jurassic. However, the studied rocks are different from the typical low Si adakites, while their w (SiO₂) values (61.13%-62.31%)are significantly greater than 56%.The traces of magmatic mixing were observed in both the field and under the microscope, reflecting that the magma experienced the evolution process of magmatic mixing in an open system during the emplacement process.

The tectonic environment of the formation of the Zaheba ophiolite, an important component of the Aermantai ophiolite belt in East Junggar, Xinjiang, remains highly debated. In order to determine the physicochemical condition and tectonic environment of the formation of the Zhaheba ophiolite in Xinjiang, fresh unaltered chromites were selected for electron microprobe analysis. The result shows that chromites contain uniform compositions of Cr2O3 (52.62% to 56.66%), Al2O3 (7.87% to 12.69%) and TFeO  (16.70% to 19.56%), with Cr# values of 73.58-83.80, Mg# values of 55.30-63.09, Yfe values of 4.02-8.00 and Fe2+#values of 36.91-44.70. They are mainly  chromites and a few high-iron spinel-rich chromites. The estimated average temperature and pressure for crystallization of the chromite are 1 307.84 ℃ and 4.08 GPa, respectively, inferring a formation depth of approximately 126.34 km. It is inferred that the Zhaheba chromite-hosting peridotite could be derived from the garnet lherzolites in the depleted upper mantle with mantle oxygen fugacities of 0.14 to 1.21 log units (average 0.59 log units) and degrees of partial melting of the mantle from 22.67% to 23.23% (average 22.91%). Therefore, the chromites show the characteristics of a super-subduction zone, and we suggest that the Zhaheba ophiolite was formed in the intra-oceanic back-arc basin in a subduction zone.

 Qaidam basin is the main salt storage ore belt in China. At present, there have discovered 12 kinds of minerals with proven reserves and resources, among which the reserves of potassium chloride, magnesium chloride and lithium chloride rank first in China. At the same time, many deposits/ore bodies in new regions, new horizons, new types and new depths have been discovered, showing that Qaidam basin has great prospecting potential. Based on the division of national metallogenic units, using the latest research results, on the basis of Qaidam basin in the Cenozoic geological tectonic environment, highlighting the principle of salt minerals, this paper comprehensively analyzes the lithofacies, paleoclimate, hydrological conditions, salt metallogenic laws and metallogenic characteristics of salt bearing minerals, and systematically divides the salt metallogenic units of Qaidam basin. In this paper, it is proposed that the Grade Ⅰ metallogenic domain belongs to the Qin-Qi-Kun metallogenic domain, the Grade Ⅱ metallogenic province belongs to the Kunlun metallogenic province, and the Grade Ⅲ metallogenic belt is the Li-B-K-Na-Mg-salt-oil-gas-glauber’s salt-natural alkali metallogenic belt in the Qaidam basin; It is further divided into five Grade Ⅳ metallogenic subzones: The boron-lithium-potassium mineralization subzone in the northern margin of Qaidam basin, the central potassium-halite-magnesium-lithium-celestite-mirabilite metallogenic subzone, the boron-potassium-halite-mirabilite mineralization subzone in the north of Kunlun, the Chaerhan potassium-halite-magnesium-lithium-boron-trona metallogenic subzone, and the Delingha halite-trona metallogenic subzone; and 21 Grade V ore concentration areas.

The Qinhuangdao area of eastern Hebei is located in the eastern part of the North China plate, where Mesozoic volcanic rocks are widely developed. In order to further study the tectonic setting and movement mechanism of Mesozoic magmatism in this area, the LA-ICP-MS zircon U-Pb geochronology, Hf isotopic compositions, major and trace elements of the rhyolitic crystal tuffs in Rugezhuang were analyzed. The results show that zircons have a clear oscillatory zoning, and the Th/U value of zircons is 0.37-0.83, indicating they are magmatic zircons with the weighted average age of (113±1) Ma. The rocks are characterized by high silicon (75.95%), high alkali (8.47%) and low calcium (0.39%). HFSE (Th, U, Ce, Nd, Zr, Hf) are enriched and LILE (Ba, Sr, P, Ti) are depleted in analyzed samples. The REE distribution patterns dip slightly to the right, andδEu (0.02-0.30) is obviously negative anomaly, suggesting that a large amount of plagioclase was crystallized. During the evolution of the magma, along with the crystallization of apatite, ilmenite and other minerals, the value of Nb/Ta is close to that of the continental crust, suggesting that analyzed rocks have the characteristics of crustal rocks. Zircon Hf isotopic compositions and temporal variations show that the magma source of the rocks is the product of partial melting of the ancient lower crust of the North China plate in the Late Early Proterozoic to Middle Mesoproterozoic due to the heating from mantle-derived magma. The results show that the rhyolitic crystal tuffs in Rugezhuang are the products of magmatic activities in the Early Cretaceous, and was formed in the intraplate extensional environment driven by the subduction and roll-back of the Paleo-Pacific plate.

Zhangguangcai Range is located in the central-southern part of Heilongjiang Province and the central part of Jilin Province. The north-south magmatic arcs developed in the Zhangguangcai Range are the products of collision-collage of microplates, which can effectively determine the collision-collage age of Songnen block and Jimusi block. In this paper, systematic zircon U-Pb geochronology and petrogeochemistry of the Middle Jurassic porphyritic monzogranites in Qingsong, Southern Zhangguangcai Range, have been carried out to explore its geological significance. The zircon U-Pb geochronology shows that the petrogenic ages of porphyritic medium-fine grained monzogranites and porphyritic medium-coarse grained monzogranites are (172.1±1.3) Ma and 172.1-172.4 Ma respectively, indicating their diagenetic ages belong to the Middle Jurassic. Geochemical results indicate that the porphyritic monzogranites are low in Si and Al, high in alkali, K and TFeO/MgO values. The chondrite-normalized REE patterns of porphyritic monzogranites with a slight dipping to the right display enrichment in elements of (Rb, K,  U, Th, La and LREE and depletion in elements of Nb, P, Ti, Y, Yb, Lu and HREE The porphyritic monzogranites belong to type I granites, and their magma originatesd from the crust-mantle mixed source area. Combined with the characteristics of chronology and geochemistry, the Middle Jurassic porphyritic monzogranites were formed in the syncollisional tectonic setting, which is closely related to the collision-collage of the Jiamusi block and the Songnen block.

The Shabaosidong pluton located 5 km east of the Shabaosi gold deposit in Mohe area, Heilongjiang Province, is a newly discovered Early Paleozoic granitic intrusion in the Northern Great Xing’an Range. In this paper, LA-ICP-MS zircon U-Pb dating, major and trace elements, and isotope geochemistry were carried out. Zircon U-Pb dating results indicate that the formation age of the intrusion is (509±4) Ma. The pluton has high SiO2=66.20%-71.83%, Al2O3=14.61%-15.08%, K2O+Na2O=6.37%-8.10%, and belongs to weak peraluminum, high potassium and calcium alkaline series. It also shows enrichment in light rare earth elements, large-ion lithophile elements (Rb) and high field strength elements (Th and U), depletion in heavy rare earth elements, high field-strength elements and large-ion lithophile elements (Ba and Sr). The zircon  εHf(t) values range from 2.7 to 5.6 and the two-stage model age is 1.3 to 1.1 Ga. The Shabaosidong granite was formed in a post-collisional orogenic tectonic environment and was the products of partial melting of the juvenile lower crust.

 The Petrogenesis of the Awengcuo-Yanhu magmatic arc in Lhasa terrane is the key to solve the subduction polarity and time of the Bangong-Nujiang Tethy Ocean. In this paper, the monzonitic granite in the north Awengcuo was selected for petrography, geochemistry, zircon U-Pb geochronology and Hf isotopic studies. The zircon ²⁰⁶Pb/²³⁸U weighted mean age of the monzonitic granite is (107.0±0.5) Ma, MSWD＝2.6, belonging to the Late Early Cretaceous. The samples are a series of high-silicon and potassium-rich high-potassium calc-alkaline rocks with A/CNK values ranging from 1.006 to 1.019, belonging to weak peraluminum. The trace elements are enriched in large ion lithophile elements Rb, K, U, Th and LREE, depleted in high field strength elements such as Nb, Ta, P, Ti, with moderate to weak negative Eu anomalies (δEu = 0.55-0.78), belonging to a weakly peralumious undifferentiated I-type granite. The monzonitic granite yields the zircons ε_Hf(t) values of 3.7-6.3 with a mean of 5.0, except for one characteristic value of 11.1, and the model ages (t_DM2) range from 928 Ma to 765 Ma. Based on integrated isotopic and geochemical data, the north Awengcuo pluton is probably formed by the heterogeneous mixing of felsic magma and mafic magma generated by the melting of the juvenile crust, with the participation of a small amount of mantle-derived materials. Combined with Hf isotope analysis of magmatic rocks in the north-central Lhasa terrane, the Awengcuo-Yanhu magmatic arc was formed under the tectonic regime of the backward subduction of the Bangong-Nujiang Tethy Ocean, and the formation age of the pluton from the north Awengcuo (107-104 Ma) represents the time for the transformation from the end of slab break-off to the collision environment.

Halongxiuma molybdenum polymetallic deposit is the only medium-sized porphyry deposit in the eastern part of the East Kunlun metallogenic belt. Based on the detailed study of fluid inclusions and H-O-S isotopes, this paper finds out the nature of ore-forming fluids and the source of ore-forming materials, and constructs the metallogenic model of this deposit. Petrography and microthermometry of fluid inclusions show that two types of inclusions, namely gas-liquid two-phase and CO₂ containing three-phase, are developed in Halongxiuma deposit. The ore-forming fluids are characterized by medium to high temperature (concentrated in 280-340 ℃), high salinity (concentrated in 6.00%-18.00%) and medium density (concentrated in 0.64-0.92 g/cm³), and the metallogenic depth is 2.4-4.1 km, suggesting that the deposit was formed in a meso-epithermal environment. The results of H-O isotope show that the ore-forming fluids are derived from the mixing of magmatic and atmospheric water, and the main component is magmatic water; The results of S isotope show that the ore-forming materials mainly come from the deep magma. Combined with the regional tectonic evolution, it is considered that the metallogenic model of Halongxiuma deposit is as follows: Firstly, intense crust-mantle mixing occurred in East Kunlun area during the Late Indosinian, producing a mixed magma rich in ore-forming elements; Then the ore-bearing fluids boiled during the ascent of the mixed magma and cooled down due to the addition of [JP2]atmospheric water, resulting in the changes in the physical and chemical conditions of mineralization, and promoting the precipitation of metallogenic materials.

 The genetic mechanism of Chang’an gold deposit in the southern section of  Ailaoshan metallogenic belt in Southwest China remains to be restricted. To understand the source of ore-forming materials and fluids, and to illustrate its genetic type of deposit could provide a basis for the mine prospecting and reserve increasing. In this paper, the source and evolution of metallogenic materials and fluids in Chang’an gold deposit are studied based on detailed geological features, ore H-O-S-Pb isotope analysis and temperature measurement of fluid inclusions, and then the genesis of the deposit is restricted and the metallogenic model is established. The results show that the near-SN-trending F₆ considered by predecessors is not a fault, but a cryptoexplosive breccia tube, which is the main ore hosting structure of Chang’an gold deposit. In the main metallogenic stage, the freezing point temperature of the inclusions is mostly -2.9--0.7 ℃, the corresponding salinity (w (NaCl)) is 1.22%-4.79%, and the homogenization temperature is 162-226 ℃, which belongs to the low temperature and low salinity fluid system. The δ¹⁸O_H2O of quartz in the main metallogenic stage is between 4.4‰ and 5.2‰, and the δD is -93.9‰--85.9‰, which falls between the evolution line of magmatic water and atmospheric water, indicating that the ore-forming fluid is a mixture of magmatic fluid and atmospheric water. The averageδ³⁴S of pyrite in Chang’an gold deposit is 2.1‰ (n = 32), most of which are between 0.0 and 3.6‰, with obvious characteristics of magmatic sulfur suggesting that S comes from magmatic rocks. The lead isotopic composition of pyrite has obvious duality, reflecting the dual contribution of magmatic and upper crustal surrounding rocks. Therefore, it is considered that the ore-forming materials and fluids are mainly derived from magma, and the later atmospheric water and surrounding rocks also contribute to the metallogenic fluids. Chang’an gold deposit, which has similar characteristics to low-sulfidation epithermal gold deposits, is dominated by cryptoexplosive breccias, although its surrounding rocks are not traditional volcanic rocks.

The Huangyanggou diorite porphyrite pluton intruded in the limestone of the Late Jurassic Hongqilafu Formation, which is located in Tianshuihai-Kalakunlun Terrane. In order to determine its formation age and reveal the petrogenesis and tectonic background, LA-ICP-MS zircon U-Pb geochronology and whole-rock geochemical analysis of Huangyanggou diorite porphyry were carried out.The zircon U-Pb age of the pluton is 159.9 Ma, which is formed in a post-collisional extensional environment. The magma source is characterized by mantle source, with the assimilation and mixing of crustal materials, which indicated the formation conditions were low pressure, strong oxidation environment and experienced intermediate differentiation. The pluton is characterized by low silicon (w(SiO₂)=56.11%-57.36%), high calcium (w(CaO)=4.29%-6.59%), and alkali-rich (w(Na₂O+K₂O)=6.00%-7.96%), and belongs to quasi-aluminous (A/NCK=0.79-0.95) rocks. It is also enriched in large ionic lithophile elements (K, Rb, Ba, Th, U) and depleted high field strength (Nb, Ta, Zr, Hf) elements, with a weak Eu negative anomaly (δEu mean 0.97). Through the comparative study of the regional magmatic activities, the Huangyanggou pluton has a strong affinity with the Pa’a I-type granite in the Geji area of the Bangonghu-Nujiang suture zone, and is consistent with the formation ages of the magmatic rocks exposed in this suture zone. It indicates that the Huangyanggou diorite porphyrite in the south of the Tianshuihai terrane is a magmatic response to the southward subduction of the Meso-Neo-Tethys Ocean in the northern Bangonghu-Nujiang suture zone.

  Aritekshan Cu-Mo deposit is a newly discovered concealed porphyry deposit, located in the central-north part of the northern Qaidam basin. The orebodies occurred in the contact area between the Late Hercynian-Indosinian granodiorite (porphyry) and Paleoproterozoic Dakendaban Group. In order to explore the characteristics of ore-forming fluids, the ore-forming mechanism and genesis of the deposit, this paper systematically studied the field geological characteristics, fluid inclusions and stable isotope composition of the deposit. According to the relationship between different types of ore veins, the hydrothermal metallogenic stages can be divided into the early mineralization quartz stage, molybdenum-polymetallic sulfide-quartz stage and late mineralization quartz-calcite stage. The fluid inclusions are mainly Type Ⅰ (liquid-rich L+V two-phase aqueous inclusions), Type Ⅱ (gas-rich L+V two-phase aqueous inclusions) and Type Ⅲ (three-phase aqueous solution inclusions containing daughter minerals). The results of microthermometry and inclusion Raman spectrum analysis show that the ore-forming fluid system is NaCl-H₂O system with medium-high temperature, medium-low salinity, and medium-high density. In the late stage of mineralization, the properties of the fluids changed to low temperature, low salinity and high density fluid, with the deposit formation depth of 0.40-4.00 km. The values of D_V-SMOW and δ¹⁸ O_H2O range from -92.9‰ to -78.4‰ and -7.4‰ to 2.0‰ respectively, indicating that the ore-forming fluids are mainly mixed fluids. With the evolution of ore-forming fluids, the continuous mixing of meteoric water affects mineralization. Theδ³⁴S of metal sulfide in the ore ranges from 9.4‰ to 11.7‰, with an average value of 10.2‰, showing obvious characteristics of strata sulfur, which is caused by the interaction between magmatic hydrothermal fluid and surrounding rock strata. It is believed that  Aritekshan Cu-Mo deposit is a skarn-porphyry type deposit, which was formed in the subduction and collision during Late Hercynian-Indosinian, which is consistent with the diagenetic age of granodiorite. The strong immiscibility of mixed ore-forming fluids is the main mechanism of the formation of porphyry Cu-Mo deposit.

A set of epimetamorphic marine volcano-sedimentary rock series developed in Tuolugou cobalt (gold) mining area, Qinghai Province, of which the formation ages and tectonic attributes are controversial. In this paper, zircon LA-ICP-MS dating, Lu-Hf isotopic and geochemical analysis were carried out on the phyllites from Tuolugou deposit, and their protolith depositional ages, sediment provenance and tectonic affinity of the basement were discussed. The chronological results show that the youngest age group of detrital zircons is 433-412 Ma with weighted average age of (422.8±6.8)Ma. Combined with the data of regional tectonic magmatic events, the upper limit of the protolithic depositional age is the Late Silurian. Theε_Hf(t) values of zircons in age group of 433-412 Ma range from －2.02 to 5.47, with an average of 1.80, indicating that the parent rocks of this zircon group are mainly new crustal materials. The T_DM1 age ranges from 1 124 to 829 Ma, indicating that the zircons originated from the crust mantle interaction during the convergence of the Rodinia supercontinent in the Grenvillian period. The petrogeochemical results show that the protolites of the Tuolugou phyllites may be a set of mud-sandy sedimentary rocks, and the depositional environment is a stable passive continental margin. It is consistent with the result of regional tectonic evolution which is: The subduction of the middle Kunlun Ocean ended around 430 Ma, and the whole east Kunlun area began to enter the intraplate extension setting, while the southern part of the south Kunlun block entered the passive continental margin in the Late Silurian. The comprehensive analysis of the U-Pb age spectrum of detrital zircons shows that the original properties of detrital zircons during the Archean is not clear, and the basement of the south Kunlun in the Mesoproterozoic has obvious affinity with the South China craton. Since the Grenvillian orogeny formed the United Continent of Cathaysia-Yangzi-Kunlun-Qaidam-Qilian, the Kunlun block may have been separated from the United Continent during the Pan-African period (about 650-550 Ma)

Physical model test is an effective means to study the deformation and fracture characteristics, dynamic process, and genetic mechanism of geological disasters. Limited by the size of model box, the boundary effect is significant in the test process, so how to reduce the influence of boundary effect has always been the focus of researchers. In this study, the physical model test of the rupture propagation of buried ground fissures was taken as the research object， and the boundary effect of physical model box was systematically analyzed by means of phenomenal analysis of the physical model tests and numerical simulation verification. The results show that the main controlling factor of the boundary effect of the model box is the ratio of sidewall damping to box size. The sidewall damping is positively correlated with the amplitude of the boundary effect. When the sidewall friction angle is smaller than the internal friction angle of the soil, the cohesion is the main factor affecting the boundary effect. When the friction angle of the sidewall is larger than the friction angle of the soil, the friction is the main factor affecting the boundary effect. The box size ratio affects the amplitude of boundary effect, and the aspect ratio is positively correlated with the amplitude of boundary effect. The box boundary effect has a significant influence on the results of the physical model test on the fracture propagation of buried ground fissures. The optimal size ratio of the experimental model box is determined to be 5∶3∶2.2.

For the exploration of deep earth resources in China, the authors developed a high-power borehole induced polarization system ( referred to as borehole IP system) for mineral resources exploration within 3 000 m. Compared with  ground induced polarization method,  borehole IP system conducts exploration through drilling and its transceiver is closer to the target body, which has more advantages in the exploration of deep concealed minerals and oil and gas resources. The acquisition control and data processing of  borehole IP system is the center of the whole system. In the work, it is necessary to solve the technical problems such as data acquisition, long-distance remote communication, high-speed data transmission, and transceiver synchronization under the condition of high temperature and high pressure. Based on the high expansibility of the logging ACME (acquisition control management expert), the authors developed a set of acquisition control and processing software matched with  borehole IP system. The acquisition control software of borehole IP system is connected to  ACME  through a dynamic library to realize the functions of data acquisition, real-time data transmission, display, monitoring, storage, processing and mapping, and has been successfully applied to the borehole detection experiment of copper iron metal mine in Daye City. The data processing results are highly consistent with the known data and meet expectations.

Shuangyang Qijia water source in Changchun City is close to the oil field, and the original division of one-level water source protection zone is not enough to reconcile the increasingly prominent contradiction between oilfield exploitation and water quality safety of water sources. In order to protect the groundwater drinking water source from the influence of oilfield development activities, a new division is needed to help the oilfield development layout in the area where the drinking water source is located. Firstly, the hydrogeological conditions in the study area were analyzed, the groundwater flow models and solute transport models of the water sources were established by using the MODFLOW and MT3DMS modules in the numerical software GMS (groundwater model system) on the basis of the original primary water source protection area. Then the secondary protected area division study was carried out in Shuangyang Qijia water source area in Changchun City to determine the degree and scope of pollution caused by the oilfield development activities. The simulation results show that after 1 000 d transportation in groundwater, the pollutants are 400-800 m away from the pollution source. On this basis, a total of 33.5 km2 of the secondary protected area is designated, and the oil wells originally planned in and around the designated area should be cancelled or properly relocated.

Thallium is highly toxic to mammals. Tl(Ⅰ) is a common stable and migratory form in water, and hard to remove. In this study, Fe-Mn binary oxide composite active aluminosilicate mineral (FMAAM) was prepared via coprecipitation method by loading Fe and Mn oxides on active aluminosilicate mineral (AAM) and applied to Tl(Ⅰ) removal in water. The effects of the initial pH, ionic strength and FMAAM dosage as well as the removal mechanism of Tl(Ⅰ) were studied. The results showed that the adsorption of Tl(Ⅰ) by FMAAM reached its equilibrium at 120 min, and the removal rate was more than 89.0% at the solution pH range of 3-9. The adsorption process of Tl(Ⅰ) by FMAAM was more consistent with Langmuir model. The maximum adsorption capacity of Tl(Ⅰ) by FMAAM was 61.50 mg/g at 293 K (pH=7, a dosage of 1.00 g/L). The specific surface area (SBET), average pore size and total pore volume of FMAAM were tested, which showed that the SBET of FMAAM (36.830 m²/g) was significantly higher than that of AMM(0.165 m²/g), with a difference of more than 200 times. According to the analyses of energy-dispersive X-ray spectroscope (EDX), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), the adsorption mechanism of Tl(Ⅰ) by FMAAM is related to ion exchange, complexation reaction, and oxidation precipitation.

 Tuolahaihe graphite deposit is the first super-large scale crystalline graphite deposit discovered in Qinghai Province, which is located in the southern margin of Qaidam basin and the middle part of East Kunlun. The ore bodies appear in bedded and near bedded within gneiss, calcareous gneiss, quartz schist and marble of the Lower Proterozoic Jinshuikou Group, which belong to a typical gneiss graphite deposit. In order to discuss ore genesis, detailed petrography, whole-rock geochemistry and isotope geochemistry studies have been carried out on the ore-bearing strata. The results show that ΣREE in graphite gneiss and graphite quartz schist containing graphite is 82.95×10-6-154.86×10-6,enriched in light rare earth elements, with obvious Eu negative anomaly and weak Ce negative anomaly, showing the protoliths formed in anoxic depositional environment of the shallow sea at the continental margin. The protoliths of ore-hosting metamorphic rocks are organic-rich sandy rocks, greywacke and calcium silicate rocks, and the material sources are mainly terrigenous debris and a small amount of them are shallow marine carbonate rocks. The δ13C isotopic composition of graphite gneiss and marble indicating that   the carbon in graphite comes from bioorganic carbon, while and carbon of marble is inorganic carbon. Tuolahaihe graphite deposit is a regional metamorphic graphite deposit that formed in Paleoproterozoic.

Kast pools often lead to a trailing of breakthrough curve (BTC) in karst conduits. It is of great significance to study the influence of the pool on its breakthrough curve for predicting and controlling groundwater pollution. Different sizes and number of pools were designed and the indoor tracer experiments were performed to investigate the influence of the pool volume on its breakthrough curve. The experimental results showed that as the pool volume (pool size or pool number) increased, the BTC tailing increased and the peak mass concentration decreased; As the flow rate increased, the BTC trailing decreased and the peak mass concentration of both symmetrical and asymmetric pools increased first and then decreased. The penetration time of main solute plume in the symmetrical pool was basically constant with the increase of pool size, and increased exponentially with the number of pools. The other time characteristic parameters basically increased linearly with the pool volume, and the adjusted peak mass concentration showed a power function relationship with the pool volume. When the pool volume was the same, the time variance, the penetration time of the descending solute plume, and the tracer duration time for different pool sizes were larger than for different number of pools, while the mean migration time was basically the same for the two pool distributions. The penetration time of the main solute plume and the adjusted peak mass concentration in the asymmetric pool were basically the same for the two pool distributions. The mean migration time basically increased linearly with the pool volume in the symmetric and asymmetric pools, the penetration time of the main solute plume and the adjusted peak mass concentration respectively showed a good linear and power function relationship with the volume of the asymmetric pool. It is indicative to predict the volume of pools in karst conduits by using these three characteristic parameters of the breakthrough curve in the field.

In order to deeply understand the water cycle mechanism of Ziquejie Terrace in Hunan Province, a comparative study between the Ziquejie region and the surrounding areas was carried out to reveal the superior precipitation condition behind the terraces with the help of the concentration degree (DC) and rainfall standard index (ISP) methods, based on the precipitation data of 11 meteorological stations in the Ziquejie region and the surrounding areas from 1986 to 2015. The results show that the annual average rainfall in the Ziquejie region is 1 638.7 mm, which is 177.4 mm higher than that of the eight outer stations. The average rainfall in summer (from June to August) is 675.1 mm, which is 122.4 mm higher than the eight outer stations. The average DC of ten-day rainfall sequence of the three stations in Ziquejie is 0.373, which is significantly higher than the average value of 0.354 of the eight outside stations. Summer is the main predominant period of rainfall for the Ziquejie Terrace region. The average rainfall peak period in the Ziquejie Terrace region is in mid-June, later than the eight outside stations in early June or late May. The drought frequency of the three-month time scale shows the characteristics of “small first and then large”  from May to August in the Ziquejie region： The values of drought frequency in May and June are markedly less than the average value of the whole region, while the values in July and August are just the opposite. The main irrigation period of rice in the Ziquejie region lasts from mid-June to mid-August. The seasonal distributions of rainfall and drought frequency form a good match with the rice growth-period in the Ziquejie Terrace region, which is one of the important supporting conditions of the artesian irrigation system.

Epithermal deposits are important sources of nonferrous and precious metals as well as rare and critical metal resources such as indium. Due to their vectors toward deep porphyry mineralization, they have attracted the attentions of global geologists. The continental margin of Northeast China is one of the areas where epithermal ore deposits are widespread, characterized by epithermal Au and Ag-Pb-Zn-Cu polymetallic deposits being occur. According to the deposit geology, these epithermal-type deposits in Northeast China were divided into three types, low-sulfidation type (LS), intermediate-sulfidation type (IS) and high-sulfidation type (HS). The mineralization occurred in the Late Jurassic to Early Cretaceous volcanic basins and uplift areas spatially close to granite complex margins, comprising four separated mineralizationstages as a function of time, including (1) 151 to 141 Ma, (2) 140 to 131 Ma, (3) 123 to 120 Ma, and (4) 110 to 100 Ma. Stage 1 is restricted in the eastern portion of the Great Xing’an Range, characterized by regional epithermal HS copper polymetallic deposits. Stage 2 is developed in the western portion of the Great Xing’an Range, where large-scale epithermal LS-IS Ag-Pb-Zn mineralization. Stage 3 occurs in middle portion between the north of the Great Xing’an Range and the Lesser Xing’an Range and in Yanbian and western Liaoning, characterized by epithermal IS Cu and LS Te-Au mineralization. Stage 4 occurs in the Northern Great Xing’an Range-the Lesser Xing’an Range-Raohe-Dongning-Yanbian area. There is a younger mineralization time from the eastern portion of the Great Xing’an Range-the western portion of the Great Xing’an Range-the northern margin of the North China platform (Liaoxi+Yanbian)-the northern margin of the eastern portion of the Great Xing’an Range (Heihe) to the northern portion of the Great Xing’an Range-the Lesser Xing’an Range-Wanda Mountains-Taiping Mountains-Yanbian. There is a transition in mineralization type, from Cu polymetallic to Ag-Pb-Zn to Cu-Au + Te-Au to Au (± Sb) +large-scale Au and Cu. The tectonic environments for the various mineralization are related to the episodic subduction of ate Mesozoic Paleo-Pacific plate towards the eastern end of Eurasia, in which there is a transition from compressional to crustal extensional conditions. Except the mineralization in the Yanbian area occurring in the late stage of intermediate-basic volcanic eruption-hypabyssal emplacement, the remnant mineralization formed in the late stage of bimodal volcanic eruption-hypabyssal emplacement. Considering the genetic relation between epithermal metallic and porphyry Cu and Mo mineralization, the early-stage epithermal Ag-Pb-Zn-Cu mineralization and the coeval porphyry mineralization constitute the porphyry Mo-epithermal Ag-Pb-Zn system, whereas the epithermal LS Ag-IS Pb-Zn-HS Cu polymetallic and porphyry Cu-Mo mineralization constitute the porphyry Mo-Cu-epithermal Ag-Pb-Zn hydrothermal system. Similarly, the intermediate- and late-stage epithermal Au mineralization and Au-rich porphyry Cu mineralization constitute the Au-rich porphyry Cu-epithermal IS Cu-Au hydrothermalsystem and the Au-rich porphyry Cu-epithermal IS Cu-Au-epithermal HS Au (Cu) hydrothermal system. Nevertheless, more evidence is needed to clarify whether the epithermal LS Te-Au, Sb-Au, and Au deposits are individual ore system or not. Late Mesozoic epithermal ore systems are the results  the underplating of mantle-sourced basaltic magmas and their interactions with lower-crustal magmas during a roll-back of subducting slab and a thinning crust episode from Late Jurassic to Early Cretaceous.

 Due to its unique physical and chemical properties, cobalt is widely used in modern advanced technology fields, so some countries have listed it as an important strategic critical resource. There are few independent cobalt deposits, and co-associated deposits are the main cobalt deposits. China is a country with relatively poor cobalt resources, with external dependence exceeding 90.0%. Many large and medium cobalt deposits have been discovered and explored in northeast China, including Cu-associated deposits and Cu-Ni-Fe co-associated deposits. Therefore, it is necessary to further summarize its metallogenic geological characteristics, analyze its resource potential, and provide a reference for future exploration. In this paper, cobalt deposits are classified into four main types, i.e., sedimentary-metamorphic type, magmatic type, marine volcano-sedimentary-metamorphic type, and skarn type. The sedimentary-metamorphic type and magmatic type cobalt deposits are widely distributed, mainly in the Paleoproterozoic Liaoning-Jilin rift zone. Combined with the geological characteristics of typical deposits, regional geochemical and geophysical characteristics, 28 prospect areas were further delineated, including 4 prospect areas of class A, 8 prospect areas of class B, and 16 prospect areas of class C. Finally, four class A prospect areas are recommended as the priority areas to focus on in the deployment of prospecting and exploration in the future.

In order to further understand the origin and tectonic setting of basaltic dyke related to Middle and Late Pleistocene volcanic activities in the Heishigou area of Tianchi volcano, based on remote sensing interpretation and field geological investigation, the  geochemistry, whole rock Sr-Nd isotope and geochronology analysis of the basaltic dykes were carried out. The results show that: 1) The major elements of the dykes have relatively high MgO, CaO, K2O and relatively low Na2O, belonging to the series of potassium, metaaluminous and subalkaline basalts. They are enriched in LILEs, such as Li, Cs, Be, Rb, Ba and Sr, and weakly enriched in HFSEs, such as Nb, Ta, Zr, Hf, U and Th, and the corresponding ratios of Zr/Hf, Nb/Ta and Th/U are 40.92-45.10, 15.77-16.34 and 3.49-3.76, respectively. 2) The values of (87Sr/86Sr)i and (143Nd/144Nd)i in the whole rocks range from 0.704 570 to 0.704 690 and 0.512 552 to 0.512 571, respectively, the εNd (t) values range from 0.87 to 1.45. The K-Ar isotopic ages of (0.35-0.34 Ma) obtained by previous research in dykes and tectonic-magmatic evolution together suggest that the basaltic magmatism occurred in the Chibanian stage of Late Pleistocene, and the diagenetic parent magma has the characteristics of enriched Ⅰ-type mantle source, with a small amount of lower crust components were added during the ascent of the magma, showing the characteristic of ocean island basalt (OIB). The formation of the basalt dykes and the contemporaneous volcanic activities occurred in a compressional tectonic environment at 0.35-0.34 Ma, which may be related to the rollback or subsidence of the Pacific plate after it was subducted into the northeastern Eurasia continent.

The monzogranite in the Jiazishan of Inner Mongolia is located in the middle part of the Daxing’anling Mountains. To determine its intrusive age and tectonic environment, the geochronology and petrogeochemistry of the monzogranite have been systematically studied. The results show that the zircon U-Pb age of the monzogranite is (302.9±1.2) Ma, which is the product of Late Carboniferous magmatism. The monzogranite is characterized by high silica (w (SiO2)=74.73%-76.60%), rich alkali (w (Na2O+K2O)=6.20%-7.03%) and high aluminum saturation index (A/CNK=1.43-1.58), belonging to the high-K calc-alkaline series. Rb, K, Th and U are enriched, while Ba, Sr, Ti, Nb and P are obviously V-shaped depleted. The REE pattern shows a right-leaning enrichment type of LREE, with negative Eu anomaly (δEu=0.46- 0.67). The high differentiation index (ID) (88.89-91.55) and low solidification index (IS) (1.68-4.78) indicate that the monzogranite has undergone the evolution of high differentiation and is a type highly differentiation I-type granite with a tendency to evolve to A-type granite. The 176Hf/177Hf value is 0.282 850-0.282 951, the εHf (t) value is 9.2-12.5, and the two-stage mode age (TDM2) is 910-603 Ma, suggesting that the monzogranite may be the product of partial melting of juvenile crust in Neoproterozoic. The monzogranite in the Jiazishan area of Inner Mongolia was formed in the post-orogenic stage, and its formation may be related to the transformation of the tectonic setting from extrusion to post-collisional extension after the closure of the Paleo-Asian Ocean.

 The Middle Jurassic acidic volcanic-subvolcanic rocks are widely distributed in  Derbur area of the northern part of the western slope of the Great Xing’an Range. The rock assemblages are mainly composed of rhyolite, rhyolitic lithic tuff and quartz porphyry, and no systematic chronological and geochemical studies have been carried out on their diagenetic age, petrogenesis and diagenetic dynamic mechanism. In this paper, petrography, LA-ICP-MS zircon U-Pb dating, geochemistry and zircon Hf isotope studies were carried out on the rhyolites in  Biliya leal-zine polymetallic mining area. LA-ICP-MS single grain zircon U-Pb concordance age is (164.2±1.6) Ma (MSWD=7.7, n=14), belongs to Middle Jurassic. They have relatively high contents of major elements Si, K and Al, and belong to high-K, calc-alkaline and peraluminous rock series. Trace elements show that they are enriched in large ion lithophile elements, weakly enriched in high field strength elements, and obviously depleted in Ba, Sr, Ti and other elements.The ratios of Nb/Ta, Zr/Hf and Th/U are 13.05-22.36, 39.57-43.57 and 3.37-3.51, respectively. There are negative Eu anomalies in REE (the values of  δEu are 0.69-0.76), the ratios of LaN/YbN, La/Ce and La/Yb are  9.95-10.12, 0.48-0.50 and 14.13-15.05, respectively. In addition, they also have low 10 000Ga/Al (2.33-2.34) and (K2O+Na2O)/Cao (9.54-9.96) ratios. According to the calculation of Ti element in zircon, the saturation temperatures of zircon are between 683 and 756 ℃. These characteristics indicate that the Middle Jurassic rhyolite has the property of I-type rhyolite, and the diagenetic magma has the characteristics of volcanic arc or active continental margin magma. The 176Hf/177Hf ratios in zircons are 0.282 853-0.282 990, the corresponding εHf(t) values range from 6.22 to 10.83, and the two-stage Hf model ages range from 734.2 to 474.0 Ma, which are similar to the one-stage Hf model ages (592.6-410.1 Ma), indicating that their diagenetic magma is mainly derived from the partial melting of the juvenile lower crust. The magma was contaminated by crustal materials during the process of emplacement or diagenesis, and constituted the characteristics of “bimodal volcanic rocks” with the contemporaneous intermediate-basic volcanic rocks in this area. Combined with the temporal and spatial distribution of regional magmatic rocks and the evidence of geophysical data, it is further believed that the diagenetic geodynamic background of the Middle Jurassic acid lavas (rhyolite, rhyolitic lithic tuff and quartz porphyry) in this area is closely related to the passive continental margin which influenced by the subduction of the paleo-Pacific plate into Eurasia.

 Longgang volcanic area is located in Huinan and Jingyu County, Eastern Jilin Province, and is an important part of the Quaternary continental volcanic rock area on the continental margin of Northeast China. In order to further explore the genesis and tectonic significance of basaltic lava in the study area, based on field geological investigation, Rb-Sr isotopic dating, element geochemistry and whole rock Pb isotopic analysis were carried out. The experimental results show that: 1) The Rb-Sr isochron age of whole rocks, plagioclase and amphibole from seven trachybasalt lava samples is (1.81 ± 0.34) Ma (MSWD=0.17, n=7). 2) The values of Na2O + K2O in trachybasaltic lavas range from 6.44% to 6.65%, with high A/CNK (1.24-1.27) and Mg# (39.09-39.81) values. Compared with the primitive mantle, the trachybasaltic lavas significantly enriched in Rb, Ba, Sr and other large ion lithophile elements (LILE), enriched in light rare earth elements (LREE), weakly enriched high field strength elements (HFSE) such as Nb, Ta, Zr, Hf, U and Th, depleted heavy rare earth elements (HREE), with weak Eu anomalies (δEu=0.95-1.07) and weakly enriched in Pb. 3) The (87Sr/86Sr) i values in the studied rocks range from 0.705 074 to 0.705 206, and the ratios of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb in the whole rocks are 17.984-18.329, 15.490-15.523 and 38.315-38.400, respectively. Combined with the recent research results and the existing understanding of regional tectonic evolution, it shows that the diagenetic age of basaltic lava is the Calabrian stage of the Early Pleistocene. The diagenetic magma is mainly formed by mantle-derived magma, with a small amount of young lower crust components added, showing the attributes of oceanic island basalts (OIB) or intraplate metasomatic basalt. In addition, the formation of trachybasaltic lava and its associated volcanic activity occurred in an extensional tectonic environment at about 1.81 Ma, which may be related to the roll-back after the subduction of the Pacific plate under the northeastern Eurasia continent.

Shale oil is currently a hot and difficult topic in unconventional oil and gas research. The analysis of the types and genesis of fine-grained sedimentary lithofacies is an effective way to study the “source and reservoir” characteristics of shale oil and predict its “sweet spot”. The fine-grained sediments of the Qingshankou Formation in the Songliao basin are widely developed and are effective intervals for shale oil enrichment. Based on four parameters, including organic matter abundance, mineral composition, lithology, and sedimentary structures, six kinds of lithofacies of fine-grained sedimentary rocks of the Qingshankou Formation in the Songliao basin are divided in this paper, as clay shale with high content of organic matter and mud-grade lamination(A), felsic shale with medium-high content of organic matter and fine silt-grade lamination(B), felsic shale with medium-low content of organic matter and coarse silt-grade lamination(C), layered siltstone with low content of organic matter(D), layered ostracoid limestone with low content of organic matter (E) and layered dolomite with low content of organic matter (F). Then, the genesis of different lithofacies types were discussed from the perspectives of hydrodynamics and organic matter enrichment, and corresponding sedimentary models were established. In the static and salty water environment below the base of storm waves with high lake productivity, planktonic algae and clay flocs are uniformly suspended and settled, forming organic-rich clay lamination and lithofacies A is deposited. In a relatively static and brackish water environment below the normal wave base (with local turbulence near the wave base) with high lake productivity, the fine silt particles brought by delta runoff and flood flow continue to move towward the center of the lake basin, forming a felsic lamination through uniform suspension and sedimentation, and a clay lamination is formed during the period of intermittent suspension and sedimentation, and lithofacies B is deposited. Below the normal wave base, the flood which carries silt-grade particles are transported to the outer front of delta along the underwater distributary channel, and enter the front delta in the form of stable turbidity current. As the flow velocity gradually decreases, it forms a coarse to fine silt lamination, clay lamination is formed during the period of intermittent suspension and sedimentation, and lithofacies C is deposited. Below the normal wave base, the early sediments of the delta front, under the action of paroxysmal turbidity currents, collapse into deeper water, forming lithofacies D and E. Between the normal wave base and storm wave base, lithofacies F is formed in saline water environment under a relatively dry climate.

 The southern part of Jilin is located in the eastern section of the northern margin of the North China craton, which has experienced a long geological evolution in the Archean, Proterozoic, Paleozoic, Mesozoic and Cenozoic. The alkali-feldspar granite enriched in rare earth elements in the Late Mesozoic is widely developed in this area. In this paper, the Dachuan granite enriched in rare earth elements was selected to carry out petrography, zircon U-Pb dating and Hf isotope, petrogeochemistry analysis. The results show that the granite is mainly composed of fine-grained, medium-grained and coarse-grained biotite alkali-feldspar granite, followed by granite-pegmatite. The main elements have the characteristics of high silicon (w (SiO2) =72.56%-84.09%), low aluminum (w (Al2O3) =8.15%-14.76%), quasi aluminum-strong peraluminum (A/CNK= 0.98-1.60), belonging to the high potassium calc-alkaline series. The samples have a high rare earth mass fraction (w (ΣREE) =88.53×10-6-839.95×10-6), (La/Yb)N=2.30-41.24, enriched in light rare earth elements, depleted in heavy rare earth elements. The partition pattern of rare earth elements is right-leaning type, with obvious negative Eu anomaly and δEu value ranging from 0.05 to 0.60. The differentiation index (ID=86.72-97.69) is high, and the consolidation index (IS=0.16-1.13) is low, indicating that the magma evolution has experienced different degrees of separation and crystallization of plagioclase, biotite, apatite and other minerals. Combined with the petrographic characteristics, the Dachchuan alkali-feldspar granite is preliminarily considered as highly differentiated granite. The single zircon U-Pb isotopic age of coarse-grained biotite alkali feldspar granite is (120.8±1.6) Ma. The εHf(t) values of zircons are all negative (-10.7--5.2), and the corresponding Hf isotope second-order model ages of the zircons are 2 587-2 090 Ma. Based on isotope and petrogeochemical data, the initial magma originated from partial melting of the Neoarchean and Paleoproterozoic continental crust, and the rock mass was the product of magma emplacement after magma crystallization differentiation in the homologous magma chamber. Mineral identification and whole rock trace elements show that with the evolution of magma, the quartz content gradually increased, the biotite content gradually decreased, and the total rare earth contents also gradually decreased. The rare earth elements are mainly enriched in coarse-grained biotite alkali feldspar granite phase.

 Hydrothermal copper mineralization in the Dashihu-Dataizi area of Ji’an area, southern Jilin Province is closely related to the intermediate-acid complexes such as monzonite diorite, diorite porphyrite, monzonite porphyry and syenite granite. In order to determine the lower limit of metallogenic ages and geodynamic background, the lithography, zircon U-Pb isotopic geochronology, geochemistry and zircon Lu-Hf isotope of the medium-acid complex have been studied on the basis of field investigation. The results reveal that monzonite diorite, diorite porphyrite, monzonite porphyry and syenite granite are all products of the Early Cretaceous magmatism, and the zircon U-Pb crystallization ages are (122.7±1.8)(122.0±1.9)(120.1±1.5) and (121.4±1.9) Ma, respectively. The magma emplacement of the mineralized system occurred in the Early Cretaceous (122.7-120.1 Ma), indicating that the mineralization age of the Dashihu-Dataizi copper mineralization area was later than or approximately equal to 120.1 Ma. The geochemical data reveal that they are all enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), relatively depleted in high field strength elements (HFSEs) such as Nb, Ta and Ti, and the Eu anomaly is not obvious. All of them present high potassium calc-alkaline quasi-aluminous rocks, which are the products of different evolutionary sequences of homologous magmas. The results of zircon Lu-Hf isotope analysis shows that εHf(t) values of monzonite diorite range from -7.5 to -5.2 and TDM2 range from 1 647 to 1 500 Ma, and εHf(t) values of syenite granite range from -13.1 to -4.2 and TDM2 range from 2 004 to 1 445 Ma， fLu/Hf ranges from -0.99 to -0.95, indicating that the magma originated from the partial melting of ancient crustal materials in the Mesoproterozoic, during which there was the addition of mantle end-member materials, and the ancient materials were mixed during the ascent and emplacement of the syenogranite magma. Combined with relevant research results, it is concluded that the Early Cretaceous granitic magmatism in the study area was formed in the extensional environment formed by the subduction and roll-back of the Paleo-Pacific plate to Eurasia.

The Jiapigou gold ore concentration area, located in the collage section between the northeastern margin of the North China craton and the Xing’an-Mongolian orogenic belt, is one of the most important gold-producing areas in China. However, the origin of the ore-forming fluids and genetic types of the gold deposits in the Jiapigou gold ore concentration area  are still widely disputed. Moreover, there is still a chronic lack of systematic research on evolution of the ore-forming fluids and ore-forming mechanism. To address the problems above, this paper selects the most representative Sandaocha gold deposit in the Jiapigou gold ore concentration area  as an example to carry out a detailed analysis of fluid inclusions, laser Raman spectroscopy and H-O isotopes. Four stages of mineralization have been identified in the Sandaocha gold  deposit: (Ⅰ) milky quartz, (Ⅱ) quartz-pyrite, (Ⅲ) quartz-polymetallic sulfide, and (Ⅳ) quartz-carbonate. The stages Ⅱ and Ⅲ represent the main gold mineralization. Three types of primary fluid inclusions (FIs) are identified in quartz formed at different stages: NaCl-H2O-CO2 (C-type), NaCl-H2O (W-type) and pure CO2 (PC-type). The early-stage quartz contains C- and W-type FIs, which have homogenization temperatures of 283-411 ℃ and salinities of 4.26%-17.48% NaCl equiv. The main-stage quartz contains all three types of FIs, with homogenization temperatures of 210-288 ℃ and salinities of 2.07%-15.76% NaCl equiv. The late-stage quartz contains only W-type FIs with homogenization temperatures of 131-210 ℃ and salinities of 2.57%-14.04% NaCl equiv. The H-O isotope results indicate that the initial ore-forming fluid is the mixture of magmatic water and a small amount of meteoric water, and the meteoric water was continuously added to the ore-forming fluids during mineralization. The ore-forming fluid system evolved from a moderate-temperature and moderate- to low-salinity NaCl-H2O-CO2 system in the early stage to a NaCl-H2O system with a low temperature and salinity in the late stage. Water-rock interactions generally occurred between ore-forming fluids and metamorphic wall-rocks during fluids migration. The sudden decompression and the addition of meteoric water led to fluid immiscibility and the exsolution of CO2, H2S, and other volatiles. This process destroyed the stability of Au-S complexes and facilitated the precipitation of gold and other ore-forming elements. Comprehensive studies of geology, fluid inclusions and H-O isotopes confirm that the Sandaocha gold deposit is a mesothermal hydrothermal vein gold deposit.

 Lengshuigou Cu-Mo-Au deposit is located in the Shanyang-Zhashui ore concentration area, and is one of the representative deposits of the Late Mesozoic porphyry-skarn Cu(Mo) deposits in the South Qinling orogenic belt. In addition to the porphyry-skarn Cu-Mo mineralization, structural-altered rock-type Au mineralization in the Lengshuigou deposit is also developed, but there are always doubts about whether there is a genetic connection between Cu-Mo mineralization and Au mineralization. Therefore, Re-Os dating of molybdenite from the porphyry-skarn Cu-Mo mineralization and 40Ar-39Ar dating of altered potassium feldspar and sericite from structural-altered rock-type Au mineralization were carried out, respectively, in order to be able to pass mineralization ages to determine their genetic relationship between the two mineralization types. The results show that the Re-Os isochron age of molybdenite is (147.4±8.4) Ma, the 40Ar-39Ar ages of the altered potassium feldspar and sericite are 144 Ma, and these ages are consistent within the error range. It indicates that the porphyry-skarn Cu-Mo mineralization and structural-altered rock-type Au mineralization were formed in the Late Jurassic-Early Cretaceous, and they are the products of the same mineralization and magmatic events in the South Qinling orogenic belt. Combined with the regional tectonic evolution, the results show that the Lengshuigou Cu-Mo-Au deposit was formed in the background of the tectonic regime transition of the Qinling orogenic belt during the Late Mesozoic. In addition, the metallogenic epoch of Lengshuigou Au mineralization also shows that the Late Jurassic-Early Cretaceous Au mineralization existed in the South Qinling orogenic belt, which has important indicative significance for regional gold exploration.

 The Early Jurassic medium-grained syenogranite in Kaoshan area of central Jilin Province is exposed in the southern part of Zhangguangcai range, and emplaced in contact with the Middle Triassic granitoids and Devonian-Carboniferous intrusive rocks. Its main rock-forming minerals are composed of K-feldspar, quartz, plagioclase and biotite. In order to explore the diagenetic age, geochemical characteristics and geodynamic background of the granites in Kaoshan area, we carried out petrographic, chronological, geochemical and Hf isotope studies on the Early Jurassic non-orogenic A-type medium-grained syenogranite exposed in the study area. Zircon U-Pb geochronology and geochemical studies show that: The concordant age of the medium-grained syenogranite in the study area is (193.2±0.9) Ma, and the diagenetic time should be attributed to the Early Jurassic. It has a high SiO2 (75.49%-75.82%) and total alkali (8.28%-9.17%) mass fraction, together with high A/CNK (1.08-1.13), LREE (20.89×10-6-46.38×10-6) and FeO/MgO (3.29-5.83) values. It is also enriched in large ionic lithophile elements (LILE, such as Rb, K and Pb) and high-field strength elements (HFSE, such as Th, U, Hf, Nb and Zr). It has low MgO (0.06%-0.14%), TiO2 (0.05%-0.12%), P2O5 (0.02%-0.04%), Sr (24.20×10-6-62.59×10-6), HREE (5.14×10-6-11.80×10-6) mass fraction and medium δEu (0.41-0.56) value, which is similar to the lithogeochemical characteristics of non-orogenic A-type granite.  Hf isotopic analysis results of zircons show that the εHf (t) values range from 9.7 to 15.7, and the two-stage Hf-isotope model ages (TDM2) range from 612 to 225 Ma. Combined with the regional research data, we think the diagenetic parent magma of the medium-grained syenogranite in the Kaoshan area was probably derived from the juvenile lower crust in an extensional environment. The tectonic environment of asthenosphere mantle upwelling and back-arc extension caused by the subduction of the early paleo-Pacific plate, may be an important geodynamic factor for the Early Jurassic non-orogenic A-type granitic magmatism in the study area.

Jinya gold deposit is one of the typical Carlin-type gold deposits in the “Golden Triangle” area of Yunnan, Guizhou and Guangxi provinces. The ore bodies are obviously controlled by fault structures and are mainly layered, pod-shaped, and lenticular in argillaceous siltstone and silty mudstone of the Middle Triassic Baifeng Formation. In order to explore the metallogenic fluid properties and mineralization mechanism, the petrographic study, micro temperature measurement and Laser Raman spectroscopy analysis on the fluid inclusions in the study area were carried out. The metallogenic hydrothermal process of this deposit can be divided into three metallogenic stages: Quartz-pyrite stage (Ⅰ), pyrite-arsenopyrite stage (Ⅱ) and quartz-carbonate stage (Ⅲ), and stage Ⅱ is the main metallogenic stage. The petrographic study of fluid inclusions shows that the fluid inclusions in the metallogenic period are mainly two-phase vapor inclusions, and the liquid phase is mainly water; The gas composition is mainly CO2, N2, SO2 and CH4, and the average homogenization temperature from Ⅰ stage to Ⅲ stage is 189, 157, and 137 ℃, respectively; The average w(NaCleq) is 6.01%, 4.18%, and 2.01% in sequence. The initial ore-forming fluid is characterized by H2O-NaCl system fluid with medium-low temperature, low salinity, low density and contains volatile components such as CO2, N2 and SO2. In the early stage of mineralization, the hot brine in the basin with medium-high temperature and reducibility had a strong water-rock reaction with the surrounding strata, activating and migrating Au and S; In the main metallogenic period, the ore-forming fluid continuously flows upward driven by abnormally high pressure and faulting activities, and reacts with Fe and other elements in dolomite to form pyrite and arsenopyrite. At the same time, it mixes with atmospheric precipitation, the temperature and salinity drop rapidly, and Au and other ore-forming elements are unloaded in large quantities. In the late stage of mineralization, the ore-forming elements in the fluid were consumed, the atmospheric precipitation continued to mix in, the temperature and salinity dropped significantly, and the mineralization ended. The mineralization mechanism is fluid mixing and water-rock reaction.

The isotopic composition of seafloor hydrothermal sulfides can not only trace their sources but also record the fluids and their precipitation processes. This article analyzes the isotopic compositions of metals (lead, rhenium, osmium, iron, copper, zinc), non-metal (sulfur), and rare gases in fluid inclusions of global seafloor hydrothermal sulfides, and explores the relationship between the isotopic compositions of metals, non-metal, and rare gases in sulfides. The results indicate that there is a negative correlation between sulfur isotopic composition and osmium, iron isotopic compositions, as well as between iron, lead, and helium isotopic compositions in seafloor hydrothermal sulfides. There is a positive correlation between osmium isotopic composition and iron isotopic composition, and between xenon isotopic composition and lead, osmium isotopic compositions. During the stage of magma degassing and material injecting fluid, sulfides are formed with the characteristics of low δ34SVCDT values (about 0‰) and high 3He/4He (>8 Ra), 40Ar/36Ar (>300), and 129Xe/132Xe (>0.99) ratios. In the stage of fluid-rock interaction, as lead-containing minerals in the rock continue to dissolve, i.e., the degree of fluid-rock interaction increases, the lead content of pyrite, chalcopyrite, and sphalerite precipitated in the fluid increases, accompanied by a slight decrease in the 206Pb/204Pb ratios. In the fluid-seawater mixing stage, with the increase of seawater influence degree, the Os content (about 0×10-9) in sulfides can sharply decreased, and the δ57Fe value (<-1.6‰), the 187Os/188Os ratio (>1)  significantly increases; With the enhancement of fluid-seawater mixing degree, the δ34SVCDT values of pyrite in sulfides will increase with a slight decrease in the 3He/4He, 40Ar/36Ar, and 129Xe/132Xe ratios in its fluid inclusions, while their 3He/4He ratios will decrease with a decrease in its 130Xe/132Xe ratios. The above indicates that by comprehensively analyzing the isotopic composition and content of metals, non-metal, and rare gases, and discussing their relationships, the effects of magma degassing, fluid-rock interaction, and fluid-seawater mixing on seafloor hydrothermal circulation can be revealed, and the degree of fluid-rock interaction and fluid-seawater mixing during sulfide precipitation can be understood.

At present, the monitoring methods of personnel motion trajectory mainly rely on camera networks and thermal imaging and radar systems. However, these methods have limited monitoring range and are easily affected by light, heat sources, obstructions and distance. In response to the above problems, we have developed a new method of using distributed acoustic sensing（DAS）to recognize human vibration signals to monitor personnel motion  trajectory, which can be undisturbed and unaffected by environmental changes such as light, heat sources, and obstructions over long distances. First, the DAS signals are automatically picked up by the long-to-short time window ratio (STA/LTA) method, and then the picked-up signals are analyzed and can be divided into three types: personnel motion, hammer, and noise. Further, a convolutional neural network (CNN) architecture is constructed, and the three types of signals are input into the network as a CNN database for learning and training. Finally, the results of the three types of signal classification results are obtained through the actual data test. The accuracy reaches more than 80.00%. The recognized signal by CNN classification result can be used to determine the person's fiber channel to track the position of the person, the personnel motion trajectory can be monitored by input the updated DAS signal continuously to identify the personnel motion signal, and the motion speed can be calculated by the number of personnel movement  channels  identified per unit time.

 The Jiapigou mining district (JMD) is famous in the world for its numerous quartz vein- and altered rock-type gold deposits. The gold deposits in the JMD belong to mesothermal gold deposits and are characterized by fluids with moderate temperature and low salinity, Middle Jurassic mineralization, and genesis related to synchronic magmatism. In order to depict the process of synchronic magmatism-hydrothermalism, and tace the process of Au mineralization in this region, we present the deposit geology, petrology, and mineralogy, geochronology, and geochemistry of zircon from the Binghugou gold deposit in the JMD. The results show that: 1) Gold mainly occurs in cements of the shattered breccia; 2) Based on the morphology, internal structure, trace element composition, and U-Pb age, the zircons in the cements of the hydrothermal breccia and breccia-type ore can be divided into the captured (Group Ⅰ: 195-185 Ma), inherited (Group Ⅱ: 175-172 Ma) and hydrothermal zircons (Group Ⅲ: 176-173 Ma), and the U-Pb age of the hydrothermal zircons (Group Ⅲ) at 176-173 Ma indicating that Au mineralization occurred in the Middle Jurassic; 3) The zircons in the Groups Ⅱ-Ⅲ have low w(Y) values and high Y/Ho ratios, indicating that the late stage granitic melts coexist with the P- and Ti-rich hydrothermal fluids, and have systematic trends between w(Hf)-Th/U and w(Hf)-Yb/Gd, indicating that magma experienced gradual cooling and differentiation, and finally formed hydrothermal fluid; 4) The Ce/Ce* and Eu/Eu* ratios of the Group Ⅱ zircons are obviously higher than those of the Group Ⅲ zircons, indicating that the magma has high oxygen fugacity, and the hydrothermal fluid has low oxygen fugacity, while the values of the incompatible elements (P, Y, LREE, Nb, Th, and Pb*) gradual increase with the increase of the values of w(Hf) of the zircons (from the Group Ⅱ to Ⅲ), indicated that incompatible elements gradually entered the hydrothermal fluid phase and enriched during magmatic differentiation and magmatic-hydrothermal transition. Combined the geological observations, the magma is characterized by high temperature, high oxygen fugacity and volatile-rich components, which hindered the crystallization of sulfides in the early stage of its evolution, and promoted the enrichment of Au, S, Fe and incompatible elements in the late stage of its evolution/ hydrothermal fluid, resulting in the formation of the initial ore-bearing fluids. In the process of upward migration, abundant gold and sulfides precipitated from the ore-bearing fluids due to its unstable state caused by the intense fluid-rock interaction and decrease of pressure, temperature and oxygen fugacity, resulting in the formation of gold deposit. Combined with the regional metallogenic setting, ore geology, element geochemistry, ore-bearing fluid, and chronology of magmatism and mineralization, the above geological process is likely to have resulted in the giant gold mineralization observed in the JMD.

 Yidong Linchang gold polymetallic deposit is a recently discovered gold deposit in Lesser Xing’an range. The volcanic-subvolcanic rocks are widely distributed in the mining area, among which the diorite porphyrite and dacite are closely related to the mineralization. In this contribution, we reported petrogeochemistry，zircon U-Pb ages and Sr, Nd and Hf isotope compositions of the diorite porphyrite and dacite at Yidong Linchang gold polymetallic deposit. Geochemical studies show that the volcanic-subvolcanic rocks closely related to mineralization are peraluminous calc-alkaline volcanic rocks. All these rocks have arc magma characteristics related to subduction and are enriched in LREEs and weak negative Eu anomaly, enriched in large-ion lithophile elements (Rb, Ba) and incompatible elements (Th, U), and relatively depleted of high field-strength elements (Nb, P and Ti). Zircon U-Pb ages of diorite porphyrite and dacite are (99.60±0.62) Ma and (98.50±0.50) Ma, respectively, both formed in the Early Cretaceous. Sr-Nd-Hf isotope analysis showed that the samples have high (87Sr/86Sr)i ratios (0.707 20-0.707 70), low εNd(t) values (-3.47--2.42) and εHf(t) values (-2.22-4.11), revealing that the source area is mainly mantle with the strong contamination of crustal materials. Research results reveal that the diorite porphyrite and dacite in Yidong Linchang gold polymetallic deposit were formed in the continental arc environment of the active continental margin. The magmas were likely derived from deep-formed magmas by the partial melting of the overlying mantle wedge by the fluids released by the dehydration of the subducting Pacific Oceanic plate, and are strongly contaminated by the crust during the evolution process. On the basis of the above research and combined with the regional geological background, it is inferred that the volcanic-subvolcanic rocks of the Early Cretaceous were formed in the tectonic background of lithospheric extension as a consequence of the rollback of the subducted Paleo-Pacific Oceanic plate.

Baituyingzi molybdenum deposit is located in the south of the Xilamulun molybdenum metallogenic belt, which is a new exploration discovered medium porphyry type molybdenum deposit in recent years. This paper reports the geological characteristics, Re-Os age of molybdenite, fluid inclusions and H-O-S-Pb isotope data of  Baituyingzi molybdenum deposit to determine its metallogenic age and fluid characteristics. Molybdenum mineralization mainly exists in veinlet-disseminated, breccia-type and vein-type forms in Indosinian granite porphyry. The Re-Os isochron age of (245.4 ± 4.1) Ma for the molybdenite indicates that molybdenum mineralization occurred in the Middle Triassic. Four types of inclusions were identified: gas-liquid two-phase inclusions (W), CO2-bearing three-phase inclusions (C),  daughter crystals-bearing three-phase inclusions (S) and pure gas-phase inclusions. The Ore-forming fluid in the early stage of mineralization belongs to the CO2-H2O-NaCl system with medium-high temperature and medium-low salinity, while the main mineralization stage is characterized by medium temperature, high-salt and low-salinity coeval, and the gas-phase composition is gradually transformed into H2O-based. The fluid undergoes immiscibility during the ore-forming process, accompanied by the separation and precipitation of a large number of metal minerals. With the continuous reduction of temperature and pressure, and the addition of atmospheric water, the fluid evolved into H2O-NaCl system with medium-low temperature and low salinity and low CO2 in the late stage of mineralization. Combined with the H-O-S-Pb isotopic data, it is believed that the ore-forming materials are mainly derived from the mantle, the crust-derived materials are added in the late stage of mineralization, and the source of the crust-mantle mixture as a whole. The ore-forming fluid is derived from magmatic hydrothermal solution in the early stage, atmospheric water is added in the late stage. Therefore, we suggest that  Baituyingzi porphyry-type molybdenum deposit was formed in the post-orogenic extension environment in the Early-Middle Triassic. The source of the ore-forming materials in porphyry molybdenum deposits is mainly crust-mantle mixed or crust, while the source of ore-forming materials of copper is mantle. The oxygen fugacity and pH value of the fluid are two of the main factors for the precipitation of molybdenite.

 Aiming at the characteristics of diversity of land use requirements, various types of land cover and multiple functions in the agro-pastoral ecotone, this article introduces the land classification system to scientifically and reasonably simplify and summarize the land types, in order to achieve the sustainable economic growth of the ecologically fragile land in the agro-pastoral ecotone. Based on the interpretation data of land utilization from 1990 to 2020, and on the basis of land use classification system of production-living-ecological space （PLES）and function scores, the  agriculture and pasture interlaced area in western Jilin  Province is selected as the demonstration area, and the characteristics of spatial-temporal differentiation of PLES in the research area and its coupling and coordination changes for nearly 31 years are discussed by using the coupling and coordination model. The results show that: 1) From 1990 to 2020, the production and living space began to expand, while the ecological space showed a decreasing trend. 2) The distribution pattern and change of PLES in western Jilin Province are obviously different, the expansion of production space is mainly located on the western edge of the Songnen plain, the distribution of living space is relatively scattered with the most expansion in the core area of prefecture-level cities, and the reduced scope of ecological space basically coincides with the expanded scope of living space. 3) The overall development process of coupling and coordination in western Jilin Province is in a running-in and moderate state, and it is increasing year by year. For different levels of development in different counties, it shows the characteristics of “high in the east and low in the west”. The seriously imbalanced areas are Tongyu County and Da’an City, with poor coordination. According to the research results, it is suggested that the distribution pattern and evolution of PLES should be the basis to formulate the relevant policies and regulations, so as to support and promote the construction of ecological civilization and the coordinated development of regional economy and ecological protection.

The quantitative evaluation of pore throat microstructure has always been a hot and difficult point in the study of tight sandstone reservoirs. Taking fractal dimension as a breakthrough point, 12 core samples of Chang 6 Member of Yanchang Formation of Upper Triassic were collected from different wells in Zichang area of Ordos basin. The pore throat structure and fractal characteristics of tight sandstone samples were studied by means of scanning electron microscope, casting thin section, high pressure mercury injection and other experimental methods and fractal theory. The results show that the pore types of tight sandstone reservoirs in the study area are mainly composed of residual intergranular pores, dissolution pores and intercrystal pores. There is a obvious negative correlation between total fractal dimension and porosity and permeability, which indicates that the complexity and heterogeneity of pore throat structure of tight sandstone reservoirs in the study area have a certain impact on the physical properties. The correlation between the fractal dimension of mesopores and pore throat structure parameters is better, which indicates that the heterogeneity and surface roughness of mesopores mainly affect the reservoir space and seepage properties. There is a positive correlation between the quality of tight sandstone reservoir and the fractal dimension. The more favorable the reservoir is for oil and gas enrichment, the smaller the corresponding fractal dimension is.

The environment plays a fundamental role in the development of karst reservoirs and affects the scale and strength of karst bodies. Strengthening the study of sedimentary environments can be beneficial to the exploration and prediction of high-quality karst reservoirs. In order to deeply understand the sedimentary characteristics of the Middle and Lower Ordovician in Tahe area, the sedimentary environment is finely identified and divided by using core, logging, seismic and regional macro-sedimentary data on the basis of field survey. At the same time, the petrological and petrographic indicators, such as rock color, type and combination, structure, paleontology, geochemical characteristics, and so on, are also used to identify sedimentary environments. The results show that the rock types in the study area are mainly granular limestone, micritic limestone, biological limestone and transitional rocks. There are five types of sedimentary environments developed in total. The Penglaiba Formation is dominated by restricted and semi-restricted platform, and the Yingshan Formation is dominated by semi-restricted platform and open platform, while the Yijianfang Formation is dominated by open platform, platform margin and submerged platform. A total of 11 seismic facies are developed, which have an obvious corresponding relationship with various sedimentary facies. In general, the study area is dominated by platform facies, with obvious differences in space-time evolution. Vertically, the sea waterbody gradually deepens from the Penglaiba Formation to the Yijianfang Formation, and the sedimentary environment gradually changes from restricted to open platform. Laterally, the main body of the study area is dominated by open platform and platform margin, and gradually transits to slope and basin facies from east and south to the outside of the study area. Based on previous data, the evolution model of the study area is established. This model shows that the sedimentary environment has evolved gradually from restricted platform of the Lower Ordovician Penglaiba Formation →semi-restricted platform → open platform of the Middle and Lower Ordovician Yingshan Formation → platform margin of the Middle Ordovician Yijianfang Formation → submerged platform of the late Yijianfang Formation and the Tumuxiuke Formation.

The study of micropore structure in reservoirs is of great significance for oil and gas exploration and development. This article uses experimental methods such as nitrogen adsorption, blue-dye thin section observation, scanning electron microscopy (SEM) observation, X-ray diffraction (XRD), and nuclear magnetic resonance to study the micropore structure of the tight sandstone in the Yanchang Formation 7 Member of the Zhijing-Ansai area. The pore structure parameters and distribution are calculated, and the types of micropores are analyzed. The mineral composition, particle size, and sorting parameters that affect the development of micropores are discussed. The results show that the lithology of the Chang 7 Member is mainly feldspar sandstone. The micropore structure of tight sandstone is complex, mainly existing in the form of clay intergranular dissolution pores, feldspar dissolution pores, etc. The Chang 7 Member mainly develops small pore throats, with an average pore volume of 6.19 × 10-3 mL/g, indicating poor pore development. In the sandstone samples of the Chang 7 oil layer, the average BET (Brunauer-Emmett-Teller) specific surface area of the Chang 7 Member is 4.252 m2/g, the average total pore volume is 0.018 3 mL/g, and the average maximum pore size is 185.9 nm. The sandstone pores are mainly mesopores, followed by macropores and micropores.

Laozuoshan gold deposit in Heilongjiang Province is a large-scale gold deposit located in the north-central part of Jiamusi block, Xing-Meng orogenic belt. The ore bodies are closely related to skarn, and hosted in the contacting belt between granodiorite and calcium marble and gneiss schist of Mashan Group, as well as in the ore-controlling structures such as the NW and NWW-trending extensional fractures. The studies of deposit geology, petrography, zircon U-Pb isotope chronology and geochemical characteristics reveal that Laozuoshan gold deposit develops two superimposed mineralization stages, including the skarn-type mineralization in late Middle Permian of Variscan and the hydrothermal mineralization in Yanshan Peried. The skarn-type mineralization during the main metallogenic period is closely related to the granodiorite, and its diagenetic age is (262.6±3.9) Ma. The Variscan granodiorite in this deposit is a kind of weak peraluminous and high potassium calc-alkaline rock series, characterized by high w(SiO2), low Mg# value and MgO, with features of enrichment of large ion lithophile elements and light rare earth elements, while depletion of high field strength elements and heavy rare earth elements, showing the characteristics of I-type granite, and the magma source originates from partial melting of crustal materials. The comprehensive studies show that the Variscan skarn-type mineralization and magmatism occurred during the transition period of the tectonic regime from ocean-continent subduction to continental collision, and the granodiorite is the product of partial melting of crustal materials.

 Duhuangling gold deposit is one of the high-sulphidation epithermal gold deposits in  Yanji area, northeast China, where a large number of Early Cretaceous igneous rocks are developed. In order to understand the magmatism, magma sources and ore-forming condition of  Duhuangling gold deposit, integrated with the results of previous research, we conducted trace element analyses of zircons from the ore-bearing quartz diorite, granodiorite and granodiorite porphyry in ore district. The majority of zircons possess high Th/U values (>0.1), and their chondrite-normalized REE patterns of all zircons are characterized by HREE enrichment relative to LREE and MREE with distinctive positive Ce and negative Eu anomalies, which are typical of magmatic zircons. All the zircons yield different Ti-in-zircon temperatures, with most zircon crystals between 700 to 900 ℃. Zircon trace elements provide that the ore-bearing rocks were derived from the partial melting of the lower crustal materials and formed in the arc environment related to the plate subduction. In addition, the zircon grains have higher Ce4+/Ce3+ values and lower temperature in the melt of ore-forming granodiorite porphyry than pre-ore rocks, indicating that granodiorite porphyry has high oxygen fugacity, water contents and ore-forming potential. Therefore, the difference in magmatic oxygen fugacity and water contents may be the reasons why the quartz diorite and granodiorite are not mineralized

Oilfield A in Enping sag was located in the ancient Pearl River delta front in the Neogene period. The sand bodies were generally thin, which made it difficult to predict the reservoir. The alternating of fluvial and oceanic processes also complicated the sedimentary microfacies transformation. These factors affect the increase of reserves and production in the future. Concerning the above problems, based on fine layer correlation and logging interpretation results, the average sandstone volume fraction in sand sets is used to characterize the relative sea level changes according to the characteristics of flat terrain and fewer changes in stratum thickness of ancient delta. Research shows that the average sandstone volume fraction of Zhujiang Formation and Hanjiang Formation in the study area can better represent the relative sea level changes and accurately describe the fifth order relative sea level change. By analyzing the sedimentary microfacies of sand sets, it revealed a good correspondence between relative sea level changes and the sedimentary microfacies evolution of deltas. The feasibility of characterizing relative sea level changes based on the average sandstone volume fraction of sand layers was verified, which can be used to predict the evolution of deltas and the superposition relationship of sand bodies.

The east side of Huilu low uplift is Lufeng south hydrocarbon rich depression. In order to clarify the source and sedimentary reservoir distribution law on the east side of the low uplift, the research comprehensively uses the drilling and 3D seismic data to restore the ancient source area, describe the source to sink system elements, predict the plane distribution of sand rich sedimentary bodies, and discuss the control factors of sand body differential enrichment. The results show that Huilu low uplift develops a complete source and sink system controlled by paleogeomorphology. The lower Wenchang Formation of Paleogene in the study area can be further divided into eight uplift group units: A-H. On the basis of paleogeomorphology restoration, the eight uplift group units can be divided into 17 source and sink systems composed of independent watersheds and corresponding sedimentary areas. Among them, six independent source and sink systems composed of Watershed 1-6 are developed on the east side of Huilu low uplift, and Watershed  2, 4, and 6 have a large denudation range and denudation strength, and a large number of water systems, which are relatively concentrated. They are the main dominant source supply areas. The large denudation area, granite and volcanic rocks in Watershed 2 (eastern gentle slope of Lufeng 13 east sag) provide the material basis for the development of a large braided river delta and high quality reservoirs. The advantageous convergence of multiple water systems provides good development conditions for high-quality underwater distributary channel sandstone reservoirs.

As an important oil and gas enrichment depression in the northwestern margin of Junggar basin, Shawan depression has significant oil and gas discoveries in Hongche fault zone and slope area. In order to clarify the source of crude oil in the structural periphery of Shawan depression, the geochemical indexes of four sets of hydrocarbon source rocks and crude oil in the northwestern margin of Junggar basin were analyzed, and the oil-source correlation was studied using the whole-hydrocarbon geochemistry. It is believed that the crude oil in Shawan depression can be divided into five types with different characteristics in biomarkers and carbon isotopes. Based on the geochemical characteristics of each set of hydrocarbon source rocks, it is considered that the Subtype A1  of crude oil in Shawan depression origins from the high matured source rocks of the Xiawuerhe Formation of Permian, the Subtype A2  of crude oil comes from the normal matured source rocks of the Xiawuerhe Formation, the  Type B of crude oil derives from the intermixture of the products of the source rocks of the Fengcheng Formation and the Xiawuerhe Formation, the  Type C of crude oil originates from the normal to high matured source rocks of the Fengcheng Formation of Permian, and the  Type D of crude oil are the product of the Jurassic source rocks.

In order to study the distribution law of oil and gas near oil source faults in petroliferous basins, based on the study of spatial distribution of oil and gas migration and accumulation in different layers controlled by oil source faults, through the oil source faults transporting favorable positions of oil and gas in the lower reservoir, the spatial distribution position of oil and gas migration and accumulation between source rock and lower cap rock controlled by oil source faults is determined. The spatial distribution of hydrocarbon migration and accumulation between source rock and middle cap rock controlled by oil source faults is determined through the oil source faults transporting favorable parts of oil and gas in the lower reservoir and the leakage parts of regional mudstone caprock in the lower reservoir. The spatial distribution of oil and gas migration and accumulation from the source rock to the upper cap rock controlled by oil source faults is determined by the oil source fault in the favorable part of oil and gas transmission in the lower reservoir and the leakage parts of the lower and central regional mudstone cap rocks. A prediction methods of hydrocarbon migration and accumulation space distribution positions in different layers controlled by oil source faults was established by the combination of the three. The results show that, except the western end, the rest parts are the spatial distribution parts of oil and gas migration and accumulation from the source rock of the Es3 Formation to the caprock of the Es1z Formation controlled by Gangdong fault. The spatial distribution of hydrocarbon migration and accumulation in the source rock of the Es3 Formation and the caprock of the Ed2 Formation, which are controlled by Gangdong fault, are distributed in its middle part, the former is slightly larger than the latter. These position are respectively beneficial to oil and gas generated by the source rock of the Es3 Formation migration and accumulation to the reservoirs under the regional mudstone caprock of the Es1z Formation, the Ed2 Formation and Nm Formation near Gangdong fault, it is consistent with the oil and gas distribution found in the reservoirs under the regional mudstone caprock of the Es1z Formation, the Ed2 Formation and Nm Formation near Gangdong fault at present, indicating that the method is feasible to predict the hydrocarbon migration and accumulation space distribution positions in different layers controlled by oil source faults.

The distribution pattern of volcanic rocks in a scale of fault depression requires a unified analysis, starting from the deep magma chamber, to the transport system, and then to the eruption and distribution. However, the dominating of individual factor analyses in research process generally leads to an insufficient understanding. To fully understand the spatial distribution of the Lower Cretaceous Yingcheng Formation volcanic rocks in Changling faulted depression, the controlling effects of the magma chamber and ascending pathways are analyzed based on drilling data, seismic data and deep structures. The results are as follows: Laterally, the volcanic rocks of the Yingcheng Formation exhibit characteristics of east-west zonation and north-south blockiness, concentrating in the central depression zone. Horizontal fault throw is a sensitive parameter for determining the development of volcanic rocks, while vertical fault throw has a more significant impact on volcanic rock thickness. Faults are only a necessary condition for the development of volcanic rocks, not a sufficient one. The distribution of volcanic rocks is also constrained by up-doming of the asthenosphere and thinning zones in the crust due to extension. Volcanic material filling corresponds to the basin subsidence center in general. When the volume of volcanic rocks is limited, hydrocarbon source rocks can form a good source-reservoir combination with volcanic rocks. However, when the volume of volcanic rocks is large, it significantly reduces the deposition space for fine-grained sedimentary rocks and limits the spatial extension of hydrocarbon source rocks.

In order to analyze the Mesozoic-Cenozoic tectonic transition and its significance for oil and gas distribution in the southern Jizhong depression， based on seismic data, geological structure characteristics, structure evolution and tectonic transfer of the southern Jizhong depression are analyzed, at the same time, the geological significance for petroleum exploration are discussed. The study shows the differences in the geological structure and evolution on the two sides of the Hengshui accommodation zone (HAZ). The northern part of the HAZ is characterized by a half-graben controlled by double detachment faults with opposite dips, and the southern part of the HAZ is characterized by a compound half-graben controlled by a single detachment fault with multiple faults. The Mesozoic-Cenozoic evolution of the southern Jizhong depression can be divided into the following five periods: basement evolution stage (Mesozoic), initial rift evolution stage (Ek-Es4), strong rift evolution stage (Es3-Es2), weak rift evolution stage (Es1-Ed) and post-rift evolution stage (after Ng). The southern Jizhong depression has experienced a tectonic transition from basement NNE structural systems to Cenozoic NE systems, and the change of the stress field during the Mesozoic to Cenozoic is the dynamic reason for the formation of multi-directional complex structures. The Cenozoic transition affects the distribution of effective source rocks by affecting the migration of troughs, and influences reservoir sand distribution by controlling sand entry channels. The gradient change of displacement of main faults during structural transformation results in transverse anticline forming a favorable position indicating oil and gas enrichment. The transform structures formed by the tectonic transfer in different scales have a certain exploration potential.

Shale is mainly composed of organic kerogen and inorganic clay minerals, and the adsorption of kerogen and clay minerals on CH4 is the main source of shale adsorbed gas. In order to study the adsorption behavior of CH4, competitive adsorption behavior of CH4-CO2 and the law of CO2 embedding in inorganic clay minerals, using Na-montmorillonite to characterize clay minerals in shale, and using Lammps software to simulate fluid adsorption at different pressures, temperatures and pore sizes based on the grand canonical Monte Carlo method. The results show that with the increase of pressure, the excess adsorption capacity of CH4 increases first and then decreases at each pore size, and reaches a peak value between 11 and 12 MPa. With the increase of temperature, the excess adsorption amount of CH4 decreased gradually at each pore size. With the increase of pore size, the excess adsorption amount of CH4 decreased gradually. At small pore size, CH4 mainly exists in the form of adsorption in Na-montmorillonite, and with the increase of pore size, the adsorption state and the free state of CH4 coexist in Na-montmorillonite, and the action type of Na-montmorillonite on CH4 is physical adsorption. The CO2 displacement efficiency increases with the increase of initial CO2 pressure and pore size. CO2 storage decreases with increasing temperature, increases with increasing injection pressure, and decreases with increasing pore size. The competitive adsorption ratio of CO2 and CH4 decreased with the increase of pressure and increased with the increase of pore size.

The Shaximiao Formation in the transition zone between the central and western Sichuan basin has great potential for natural gas exploration, which has become a hot spot of exploration in  Sichuan basin in recent years. At present, there are many aspects restricting the exploration and development of tight sandstone natural gas in the Shaximiao Formation. The formation mechanism and synthesized prediction of “relatively high-quality reservoirs” are one of the key issues that need to be resolved urgently. In this paper, a series of analysis methods were performed, including systematic physical property analysis, blue-dye thin section identification, scanning electron microscopy analysis, and reservoir geochemical analysis, to determine the genetic mechanism of relatively high-quality reservoirs in the Shaximiao Formation. The results indicate that the tight Shaximiao sandstones are dominated by lithic feldspar sandstone and feldspar lithic sandstone. The average volume fraction of quartz，feldspar，and rock debris in the Second Member of the Shaximiao Formation (SMSF) are 35.27%,  35.37%, and 29.36% respectively. The average volume fraction of quartz，feldspar，and rock debris in the First Member of the Shaximiao Formation (FMSM) are 37.79%, 24.01%, and 38.20% respectively. The volume fraction of feldspar is relatively high compared to the FMSM，and the volume fraction of rock debris is relatively high compared to the SMSF. In terms of type and content of lithic fragments, sandstones in the SMSF are dominated by metamorphic fragments, accounting for 55% of the whole lithic fragments. By contrast, those in the FMSF are dominated by magmatic fragments, making up to 43% of the whole lithic fragments. In addition, the reservoir pore system is predominately composed of primary pores followed by feldspar dissolution pores, in which the FMSF is characterized by a higher content of those pores than the SMSF. In the SMSF, samples with porosity above 12%  account for 38.00%, but with permeability above 1×10-3μm2 account for 25.25%. Those values in the FMSF are 3.09% and 41.22%, respectively. It is generally reflected that some relatively high-quality reservoirs tend to be developed under a tight background. The fact, that the SMSF reservoir is characterized by better porosity and the FMSF has better permeability, demonstrates that the pore structure of the FMSF reservoir is relatively better. Besides, The tight sandstone reservoir in Shaximiao Formation is controlled by litho-mineral association, hydrocarbon source system and diagenetic system. The litho-mineral association provided a material basis for the diagenetic evolution. The hydrocarbon source system controlled the dissolution intensity, and provided ions for main authigenic minerals precipitation in sandstone. The opening degree of the diagenetic system had an effect on the ions’ in-and-out, and affected the dissolution and precipitation of the diagenetic products. The difference of litho-mineral association, variation of sedimentary environment, hydrocarbon source system and opening degree of diagenetic system in SMSF and FMSF are the main reasons for the differential diagenesis.

In order to study the optimal combination depth of suspended impervious curtain and dewatering well filter in deep foundation pit dewatering project, and optimize the dewatering scheme of deep foundation pit, the deep foundation pit debasement project of Qingnian Road Station of Nantong metro was chosen as a case study, and the groundwater seepage theory and Terzaghi one-dimensional consolidation theory, a coupling mathematical model of three-dimensional groundwater seepage and land subsidence considering the variation of soil parameters with the consolidation process was established and solved by the finite element method. Using pumping test data, the visual numerical model was identified and verified. By controlling the water level in the pit and the ground settlement outside the pit, the number of pumping wells and the pumping rate were optimized, and the optimal position of the filter under three working conditions of plugging the impervious curtain into the aquifer was simulated and predicted. And the three schemes from the construction period, cost and safety and reliability and other aspects of comparative analysis, it is concluded that when the impervious curtain is inserted into the aquifer at a depth of 1/2, the filter of the dewatering well is inserted at about 9/50-9/20, that is , the buried depth at the bottom of the impervious curtain is 46.2 m,and the buried depth of the filter is 33.7-42.7 m, 17 pumping wells are adopted for dewatering as the optimal scheme.

Target detection is a fundamental and routine task in remote sensing image processing. In this paper, we design a target detection algorithm for remote sensing images based on the YOLOX network. Firstly, ASFF is added to the feature extraction module PANet to deeply mine the fine features with inconsistent scale in target detection. Secondly, an ECA-based feature extraction module is designed with efficient channel interaction to reduce the complexity of the model while paying more attention to the positive sample feature information in the feature map. Then, to avoid the problem of gradient disappearance and weak activation effect caused by overfitting, the use of swish activation function is proposed. Finally, experiments are conducted on DOTA to verify the best mechanism and effectiveness of the improved method through qualitative analyses of the ablation experiments and quantitative comparison experiments. With the addition of ASFF and ECA mechanisms and the optimization of the swish activation function, the improved network model achieves an mAP of 74.42%, an improvement of 12.75% over the original network. Compared with the current widely used target detection algorithms Mobilenet-YOLOv4, YOLOv4, YOLOv5 and YOLOX, the proposed  algorithm achieves an improvement of 11.42%-17.84% in mAP accuracy.

With the significant improvement of high-density acquisition and daily acquisition efficiency, the amount of exploration data is growing exponentially. In order to save storage space and improve transmission efficiency, the research on high-fidelity compression and reconstruction of prestack seismic data is extremely urgent. EZW (embedded zerotree wavelet) algorithm has excellent compression performance. The traditional EZW algorithm for seismic data compression is based on data in the t-x domain. Because the wavenumber of prestack seismic data is wide and the frequency band is limited, the energy of the discrete cosine transform (DCT) data is mainly concentrated in the low-frequency in the DCT domain. This paper proposes a frequency division seismic data compression technology. Firstly, 2D-DCT is performed on the t-x data, and then frequency division is applied to the 2D-DCT data to obtain high-frequency and low-frequency data. By separately coding high-frequency and low-frequency data based on EZW, the low-frequency data has a high coding level to ensure the signal-to-noise ratio (SNR) of the reconstructed data, and the high-frequency data has a low coding level to improve the data compression ratio (CR). The synthetic data and field data experiments show that the compression ratio with the proposed method is higher than that with the conventional EZW at the same SNR.

 Enormous breakthrough have been made in shale oil exploration of Fengcheng Formation in Mahu sag, Junggar basin. However, according to generally accepted evaluation standard of shale oil source rock, the quality characteristics of source rocks in this area are not ideal. In order to scientifically evaluate the quality of source rocks in Mahu sag, the sedimentary environment of Fengcheng Formation was studied, and the source rocks was evaluated according to the mineral composition of fine-grained rocks on the basis of systematic core observation and organic geochemical analysis. Fine grained rocks of Fengcheng Formation in Mahu sag were mainly deposited in normal semi deep lake, salinized semi deep lake and semi-salinized semi deep lake, hydrothermal semi deep lake and shallow lake. The organic matter characteristics of fine grained rocks in each environment are different, and the semi-salinized semi deep lake was favored to enrich organic matter, and the averaged TOC was nearly 1%. Further combining with the discrimination diagram of organic matter types, it showed that the source of organic matter in salinized semi deep lake and hydrothermal semi deep lake was dominated by aquatic organisms, while there were mixed organic matter sources of lacustrine and land in other environments. Based on the hydrocarbon generation potential evaluation and maturity estimation of organic matter (Vre=0.74%), it was revealed that the source rocks of Fengcheng Formation were in the mature stage of hydrocarbon expulsion, and the free hydrocarbons in fine-grained rocks were identified as primary hydrocarbons. Finally, due to the difference of adsorption capacity of different mineral composition of source rocks, the classification evaluation is carried out according to continental argillaceous source rocks and carbonate source rocks. The results showed that the Fengcheng Formation deposited effective source rocks with a cumulative thickness of nearly 250 m, with organic matter dominated by algae.  

Geothermal energy exploitation and utilization are closely related to groundwater transport and the evolution of water environment. In this study, wereviewed the development status and typical mining technologies for the shallow geothermal energy stored in the soil and phreatic aquifers, median-to-high-temperature geothermal energy in deep aquifers, and high-temperature geothermal energy stored in the hot dry rocks for informational purposes of sustainable development and utilization of large-scale geothermal resources. In particular, the shallow geothermal energy can be classified into ground source heat pump and ground water heat pump according to the subsurface heat source; Median-to-high-temperature geothermal energy can be exploited mainly by direct mining, combination of production and injection and standing column well system; And high-temperature geothermal energy can be exploited using enhanced geothermal systems (EGS) through reservoir reconstruction technique such as hydraulic fracturing or chemical stimulation. Furthermore, the potential impact of geothermal energy exploitation on the groundwater resources was analyzed and summarized following the reported site cases, mainly focused on the cold and heat accumulation brought by heat pump technology, the decline of groundwater level caused by hydrothermal exploitation and the possibility of microseismic events or fracturing fluid leakage caused by hydraulic fracturing of hot dry rocks. In the end, the approaches were proposed to promote the sustainable development of geothermal resources and reduce the negative impacts on groundwater resources, including improving the recharge capacity, maintaining the water balance in the process of mining and irrigation, maintaining the heat exchange efficiency and the re-balance of underground heat, and adopting new materials. 

Affected by geological conditions, acquisition environment and other factors, it is always impossible to obtain complete seismic data in the process of geological exploration, which seriously reduces the efficiency of subsequent geological interpretation work. With the development of computer GPU hardware and seismic data processing methods based on convolutional neural networks, more and more deep learning methods are applied to seismic data regularization. At present, such methods are usually limited to processing in the time domain, which often leads to too smooth reconstructed data and a lack of texture detail information. In this paper, a convolution neural network model with joint time-frequency domain characteristics is proposed. Through joint constraints in the time domain and Fourier domain of seismic data, the multi-dimensional distribution characteristics of seismic data in the time-frequency domain are extracted, and the weight of the joint loss function could be modified to adjust the attention of convolution neural network learning. The middle layer of the convolutional neural network is constructed by multi-level adjustable residual blocks to improve the ability of feature extraction. The number of residual blocks can be adjusted according to the needs of the task to balance the accuracy and efficiency of the network. Experiments show that the proposed method in this paper has a better detail retention effect and robustness than other methods.

As one of migration channels between sediment source and sink, the influence of paleochannel on sedimentary budgets has attracted much attention from marine sedimentologists. In order to study the sedimentary characteristics of buried paleochannel in the Shapa area of Yangxi, Guangdong, paleochannels on coastal shelves have been characterized in western Guangdong. Based on the survey data of shallow strata profile of offshore wind farms and boreholes, several buried paleochannels have been firstly identified by the acoustic pulse characteristics. The results show that the channel cross sections are mainly in the shape of wide “U”, with width of 768-2 743 m and a maximum incision depth of 16.90 m, and there is a local confluence of paleochannels. Based on the modern river type discrimination method, the regional paleochannel belongs to the gravel branch type, mainly transporting sand and gravel, with an average annual transport volume of 3.87×108 m3/a. Regional paleochannels were formed in the early to middle Holocene originating from the ancient Moyang River system, and covered by the shallow marine deposits since the middle Holocene. This finding makes up the gap in the distribution of paleochannels in the shallow coastal area of western Guangdong.

In order to explore the impact of human activities on the habitats within the ecological conservation redline, improve the supervision ability of the ecological conservation redline and provide scientific support for improving the supervisory system of the ecological edprotection red line. Taking Zhenlai County of Jilin Province as an example, the high-resolution remote sensing images and related human activity data were used to assess the habitat risk of the area of ecological conservation redline form grid scale based on InVEST model and the spatial analysis capability of GIS. The results showed that: The total habitat risk value in the study area ranges from 0.00 to 1.32. High, medium and low habitat risk areas respectively accounted for 2.31%, 3.26% and 22.12% of the ecological conservation redline area. The impact of human activities disturbance on the habitat in the entire assessment area was dominated by low habitat risk. Among various habitats, the average habitat risk value of forest land was the highest, among which the average habitat risk values of arbor forest land, shrub forest land and other forest land were 0.58, 0.88 and 0.79 respectively, and the highest habitat risk value (shrub forest land) also appeared in the forest land habitat. Compared with other human activities, the cumulative habitat risk values and average habitat risk values of urban village and industrial and mining land were the highest, which were 2 933 161.90 and 1.24 respectively, followed by highway land, which were 1 086 264.68 and 1.19 respectively. Human activities such as dryland, paddy field and fishery had limited impacts on the habitat.

The Dashihugou porphyry copper deposit in eastern Liaoning Province is located in the Liao-Ji orogenic belt at the northeastern margin of the North China craton, and its mineralization is spatially closely related to the diorite porphyrite veins intruded into Dashihugou granites. This paper reports for the first time the formation age of diorite porphyrite and its zircon genesis, discusses its metallogenic potential, and provides a theory for regional prospecting. Zircon U-Pb isotopes and trace elements of diorite porphyrite were determined by LA-ICP-MS. Zircon U-Pb dating results show that the emplacement time of diorite porphyrite is 225.6-218.7 Ma, which belongs to the Late Triassic. The study indicates that the magmatic activity of this period is closely related to the first stage of copper mineralization at the same time. Zircons have a typical magmatic origin, and trace elements have characteristic of high REE abundance values with ΣREE content of （216.3-1 305.9）×10-6. Meanwhile, zircons have positive Ce anomaly and weak negative Eu anomaly. The formation temperature of zircons is 568-913 ℃ using Ti thermometer and the oxygen fugidity ranged from ΔFMQ-0.05 to ΔFMQ+4.05, which indicates that the granite has metallogenic potential of porphyry-type copper deposit. Combined with the regional geological tectonic history and zircon trace element characteristics, the magmatic activity of this period may be related to the partial melting of the lower crust caused by the upwelling of the asthenospheric mantle related to plate segment detachment during the continental deep subduction process.

Mesozoic volcanic rocks widely developed and show significant hydrocarbon potential in Bozhong Sag, Bohai Bay basin. However, there is still a lack of in-depth understanding of the reservoir-forming mechanism of high-quality Mesozoic volcanic reservoirs. Based on the analysis results of blue dye thin section, scanning electron microscopy, physical property test, high-pressure mercury injection, nuclear magnetic resonance, and nitrogen adsorption, the reservoir spaces, porosity and permeability, microstructure of pores are analyzed, and the forming mechanism and distribution of high-qualitty reservoir are discussed. The Mesozoic volcanic reservoirs were divided into two types, high porosity with mid-low permeability (Class Ⅰ reservoir), and mid porosity with low permeability (Class Ⅱ reservoir). The low porosity with low permeability volcanic rocks can not form effective reservoirs (Class Ⅲ, non-reservoir). The Class Ⅰ reservoir is composed of intermediate-acid vesicular lava altered by cryptoexplosive brecciation and dissolution. The Class Ⅱ reservoir is composed of massive intermediate-acid lava altered by cryptoexplosion brecciation and dissolution, or basic vesicular lava altered by dissolution. The main forming mechanism of favorable volcanic reservoirs in the Bozhong sag benefitted from the primary pore, fracture, dissolution, and devitrification. A reservoir development model is established, which is characterized by vertical multi-layers and lateral multi-centers of high-quality volcanic reservoirs under weathering background. Two types of volcanic bodies, multi-eruption unit, multi-mound superimposed acid composite lava volcano, and intermediate-acid intrusive lava dome, are important exploration targets for high-quality volcanic reservoirs in the Bozhong sag.

Existing drilling and seismic data reveal that Mesozoic strata are widely developed in the southern South China Sea (SCS)．In order to further understand the distribution characteristics and oil and gas geological significance of the Mesozoic strata in the southern SCS，the latest satellite gravity data are used to invert the depth and thickness of Mesozoic strata in this paper．Firstly，the gravity field forward modeling technique is used to eliminate the influence of the sea water，and the Bouguer gravity anomaly in the southern SCS is obtained． Secondly，in order to eliminate the influence of the Cenozoic sedimentary layer，this layer is divided into three layers： 0-3 km，3-6 km and 6-10 km． According to the relationship between density and depth obtained by predecessors in the SCS，the gravity influence of Cenozoic sedimentary layers is calculated by using the variable density Parker forward modeling method, and it is subtracted from the Bouguer gravity anomaly． The Pre-Cenozoic gravity anomaly was obtained. On this basis，the wavelet multi-scale decomposition technique is used to eliminate the gravity influence of deep Moho and local rock mass，so as to calculate the gravity anomaly derived by Mesozoic strata．Finally，the depth and thickness of Mesozoic strata in the southern SCS are derived by using the 3D Parker variable density interface fast inversion technique． The inversion results correspond well with the known Mesozoic wells． The Mesozoic strata in southern SCS are mainly distributed in Liyue Bank, the north part of Palawan Island and Wan’an area，with the thickness less than 9 km，while in most other areas less than 1 km or no Mesozoic strata．The Mesozoic is the most developed in Liyue Bank area, followed by the northern part of Palawan Island. Combined with the previous research results of oil and gas geological conditions in this area, it is concluded that the Mesozoic of Liyue Bank area in the southern SCS has a good oil and gas exploration prospect.

Peridynamic theory uses integral form of motion equations, which can effectively avoid the problem that the spatial partial derivative does not exist. It is widely used in simulating discontinuous problems such as crack propagation and fracture damage in different material models. However, there are few studies on wave propagation and dispersion characteristics in peridynamic theory model. In order to study the propagation law of waves in peridynamic theory model, in the case of plane stress, the equations of motion in integral form are established, and the wavefield numerical simulation of isotropic plate model and plate model with parallel cracks are carried out, and the wavefields of longitudinal and shear waves in the classical continuum theory are compared and analyzed. Based on motion equations of ordinary state-based peridynamic theory, the dispersion relations for 1D and 2D are derived in detail. The influences of peridynamic parameters such as the number of material point, the radius of the horizon and the shape parameter on the dispersion curves are comprehensively discussed. In wavefield numerical simulation, the wavefield numerical simulation results of the linear peridynamic solid (LPS) model and the linear elastic solid of the classical continuum theory are in good agreement. The existence of cracks in the model will cause reflection and diffraction of waves during propagation. In the analysis of dispersion characteristics, the dispersion characteristics of LPS model are more consistent with those of the classical continuum model when the  radius of the horizon is smaller and the  shape parameter is larger.

The Bojitian gold deposit in southwestern Guizhou Province is located in the eastern section of the Huijiabao anticlinal ore field, and is a nearly super-large Carlin-type gold deposit discovered in recent years. In this paper, the breccia in the Zaofanshan ore section developed in Bojitian gold mining area was taken as the research object. Through detailed drill core observations and combined with the previous basic geological information of the mining area, we analyzed the occurrence and petrological characteristics of the breccia and their relationship with mineralization. Research shows that Zaofanshan breccia is a tectonic breccia and can be divided into two types: Tectonic hydrothermal breccia and tectonic crackle breccia. The ore-forming stages of the deposit include three stages: Quartz-dolomite,  natural gold-pyrite-arsenopyrite, and  orpiment and realgar-cinnabar-quartz-calcite. The ore-forming process of the Bojitian gold deposit is summarized as the formation of the Huijiabao anticline first, the formation of the Zaofanshan ore-bearing tectonic breccias, and finally the migration of ore-bearing hydrothermal fluids, the extraction of metallogenic materials and the formation of ore bodies. The metallogenic model of  “two rich and two poor”  in Bojitian gold deposit is constructed: The closer to the center zone of the Zaofanshan tectonic breccia pipe, the richer the orebody is, and the farther away from the central zone of the tectonic breccia pipe, the poorer the orebody is; The orebodies produced in the deep position of breccia pipe and on its both sides are richer, the orebodies produced in the upper position of breccia pipe and on its both sides are poorer.

Abstract： With the help of core observation, thin section identification, well logging identification, and compaction physical simulation experiments, aiming at the scientific problem of the vertical evolution characteristics of compaction diagenetic fractures in glutenite reservoir, taking the glutenite of Kongdian Formation in Bozhong 19-6 condensate gas field as the anatomical object, comprehensive research was carried out, and the following understandings were obtained: 1）Fractures in the glutenite reservoir of Kongdian Formation in Bozhong 19-6 are generally developed, including inherited fractures and noninherited fractures. Inherited fractures developed earlier and occurred following the original cracks along the clastic particles. Noninherited fractures mainly broke along the feldspar cleavage in the form of conjugate shear fractures. 2）Fractures are more developed in gravel particles than sand particles, and in feldspar particles than quartz particles. The degree of crushed fracture development is proportional to the brittleness index, and inversely proportional to the interstitial content. 3）Three stages of glutenite fracture development zones have been developed vertically during physical modeling, and the second fracture development zone is consistent with the distribution of fractures in the study area, which controls the development of high-quality reservoirs.

The recently discovered Malkansu Mn carbonate metallogenic zone in the West Kunlun orogenic belt, represents a significant breakthrough for economic prospecting in China. In this paper, based on the existing age of the strata in the Malkansu Mn carbonate belt, U-Pb dating is carried out on the zircons from volcanic-bearing breccia, sandy limestone and interbedded tuff in the manganese-bearing rock series in order to determine the depositional age of this strata. In combination with the background of regional structure and supergene system evolution in the same period, the geological significance of the Malkansu manganese ore belt is further discussed. Zircons from the volcanic-bearing breccia limestone in the first lithological member and sandy limestone of the second lithological member, and the youngest three zircons in interlayered tuff of the third lithological member in the manganese-bearing Kalaatehe Formation yield 206Pb/238U ages of (322.9±1.8) Ma and (322.0±5.3) Ma, respectively. In combination with the newly reported Re-Os ages of the manganese carbonate ores, the deposition of the manganese-bearing rock series can be roughly limited to the Late Carboniferous (about 320 Ma). The manganese-bearing rock series of the Kalaatehe Formation may represent a back-arc basin sedimentary sequence related to the northward subduction of the Paleo-Tethys Ocean in the Late Paleozoic. The manganese-bearing rock series deposited during the Late Paleozoic glacial period (340-285 Ma), and the manganese carbonate ores also have (REE+Y)PAAS distribution similar to modern oceanic ferromanganese deposits, indicating that the original manganese oxides precipitated slowly and were in equilibrium with seawater. This can be compared to the formation process of other sedimentary manganese carbonate deposits related to glaciers in the Neoproterozoic around the world, that is, the gradual melting of glaciers leads to the slow precipitation of dissolved Mn2+ in the form of manganese oxides. Based on this, it is speculated that the dynamic glacial activity developed in the Gondwana continent in the southern hemisphere in the Late Paleozoic had a certain impact on the geochemical cycle of Mn in the Paleo-Tethys Sea area.

Dayangshu basin is a Late Mesozoic residual basin with a low degree of exploration and research. It shows a good exploration prospect with the industrial oil flows obtained from several wells in recent years in the southern depression. A systematic understanding of the source rocks and the hydrocarbon origin of Jiufengshan Formation is still uncertain. Based on the geochemical analysis data of source rocks and crude oils, including TOC、Rock-Eval、GC-MS, and carbon isotope, the hydrocarbon generation potential of source rocks of Jiufengshan formation are evaluated, the properties of crude oils and oil source are studied. The results show that medium-good source rocks are developed in the first member (K1j1) and the third member(K1j3) of Jiufengshan Formation, with w（TOC） of 1.76% and 2.59%, w（ S1 + S2） of 4.44 mg/g and 7.36 mg/g, bitumen of 0.21% and 0.09% respectively. The organic matter type of the K1j1 is mainly type Ⅱ1 including some typeⅠ, K1j3 is mainly type Ⅱ1 including some typeⅡ2, and the vitrinite reflectance (Ro) of the source rocks in K1j1 is mainly 0.70% to 1.60%, at the mature to high mature evolution stage. Ro in K1j3 is mainly from 0.50% to 1.10% and at the mature evolution stage. The hydrocarbon generation threshold of the source rock is about 1 300 m, and the hydrocarbon generation peak is about 1 750 m. The source rock has the characteristics of early hydrocarbon generation. The crude oils are light to medium, characterized by high viscosity, high wax, low sulfur, and high saturated hydrocarbon. The crude oil enriches light carbon isotope with δ13Coil from -30.40‰ to -29.38‰, δ13C sat from -30.78‰ to -29.07‰, and δ13Caro from -29.73‰ to -27.91‰, which indicates the source of lacustrine algae. The main peaks of alkane in oil are nC19 and nC21, OEP is 1.07 to 1.08, and Pr / Ph is 0.83 to 1.10. The crude oil can be divided into two groups based on terpenoid steroid marker. Group one includes the crude oil of Wells YC1 and Y3, with relatively high tricyclic terpane, C30D, Ts/Tm, C29Ts/C29 hopane, sterane C27R/C29R, regular sterane / hopane, rearranged sterane / regular sterane, C2920S / 20 (S+R), C29ββ/(ββ++αα) and low β-carotene. Group two includes the crude oil of Well YX4 and Well Y6, with high β-carotene and relatively low sterane terpane ratios, indicating that the maturity of Well YC1 and Well Y3 oil is higher than that of Well YX4 and Well Y6, and there are slight differences in sedimentary environment and parent material source. The oil and rock correlation of biomarkers shows that the crude oil of Wells YC1 and Y3 mainly comes from the source rock of K1j1, and the crude oil of YX4 and Y6 wells mainly comes from the source rock of K1j3. The potential hydrocarbon accumulations in this area are source-reservoir integrated accumulations and lower source rocks generation-upward migration accumulations.

 A lot of geological work has been carried out in the prospecting for sandstone-type uranium deposits in the southern Songliao basin, resulting in significant achievements. In contrast, the geological exploration work for uranium deposits in the northern Songliao basin is currently inadequate. In this paper, based on the analysis of uranium mineralization conditions, such as uranium-bearing rocks, basin tectonic evolution, paleoclimate, stratigraphic evolution, distribution of sedimentary facies, development of sand bodies and epigenetic reformation, etc., the mineralization potential of sandstone-type uranium deposits in the northern Songliao basin is comprehensively evaluated, and its prospecting direction is discussed. The northern Songliao basin is rich in uranium sources and has good metallogenic conditions. Since the Cretaceous, the basin has experienced four periods of tectonic inversion, forming two main uranium prospecting targets, Upper Cretaceous Yaojia Formation and Sifangtai Formation. Inside the basin, the Yaojia and Sifangtai Formations have well-developed sedimentary facies and sandbody conditions, and the oxidation is noticeable in some areas, and the oxidation zone and uranium mineralization are also relatively developed, providing important clues for ore prospecting. Comprehensive analysis shows that the overall uranium metallogenic conditions are good in the northern Songliao basin, with the Yaojia Formation being the key prospecting strata in the eastern section, and the Sifangtai Formation in the western section. The ore exploration type is interlayer oxidation zone type.

The Jianbian farm area in Heilongjiang Province is located at the intersection of the Great and Lesser Xing’an Ranges. The multi-stage magmatic and tectonic evolution history in this area has resulted in a complex and diverse geological background for mineralization. Based on the interpretation of Landsat ETM image data in the Jianbian farm area of Heilongjiang, this paper combined the mineral spectral characteristics and the basic geological data, and used the method system of “de-interference, principal component analysis, and ratio method combined with anomaly screening” to extract the mineralized alteration information, such as iron staining and hydroxylation in the study area. Thirteen hydroxyl mineralization alteration anomalies and seventeen iron-stained mineralization alteration anomalies were identified. The mineralized alteration anomalies were mainly found in Cretaceous volcanic strata and were mainly distributed along the intersection of NE- and NW-trending faults, NNW- and SN-trending faults. They were closely related to the contact zone of Mesozoic volcanic rocks and Early Cretaceous-Early Carboniferous intrusive rocks. Combining the known geological and mineral data and field verification results, it is found that iron-stained anomalous minerals such as limonite and hematite, as well as anomalous hydroxyl minerals such as carbonation and chloritization, were commonly developed in this area. The extracted iron-stained and hydroxyl mineralized alteration anomalies closely matched physical and chemical exploration anomalies, and were highly consistent with known Au, Cu and Mo occurrences and mineralized occurrences. This provides a theoretical basis and direction for the next step of mineral exploration in the study area.

In order to effectively solve the problem of iron and manganese overload in groundwater, this paper proposes a new method of removing iron and manganese by combining powdered activated carbon (PAC) and ozone, and explores the mechanism of the effect of PAC in treating iron and manganese in water by ozone oxidation. The effect of PAC and ozone on the treatment of Fe and Mn alone was firstly investigated; Then the effect of PAC and ozone on the treatment of Fe and Mn in combination was investigated, and the effect of different conditions (pH, temperature, PAC dosage, and oxidant concentration) on the removal of Fe and Mn in water was investigated; Finally, the mechanism of the effect of PAC on the treatment of Fe and Mn in ozone oxidation water was investigated. The results showed that PAC could enhance the oxidation of Fe and Mn by ozone under different conditions. Under the conditions of PAC dosage of 0.3 g/L, ozone mass concentration of 5 mg/L, pH of 7.0, and room temperature, the mass concentration of Fe and Mn mixed solution rapidly decreased from 0.5 mg/L to 0.1 mg/L within 5 min, which met the requirements of corresponding emission standards; With the increase of PAC dosage, the residual concentrations of Fe and Mn gradually decreased, which indicated that the reaction was highly dependent on the active sites on the surface of PAC, further confirming the effect of PAC on the removal of Fe and Mn from water. The characterization results such as scanning electron microscopy (SEM) and Mapping analysis showed that the reaction formed iron oxide and manganese oxide coatings on the surface of PAC, and these oxide coatings would further accelerate the removal of free iron and manganese from water.

Channel sand is one of the important oil and gas reservoirs. The quantitative prediction of sand body thickness is the key to improve the efficiency of oil and gas development. With the enhancement of non-homogeneity of target reservoir, the relationship between seismic attribute and reservoir lithology, physical property and pore fluid becomes more complicated. How to achieve efficient and intelligent quantitative prediction of complex reservoirs under the condition of limited geological information is currently a hot and difficult topic in the field of reservoir prediction. To achieve high accuracy and intelligent prediction of the tight sandstone reservoir, a reservoir effective sand thickness prediction method based on deep fully connected neural network is proposed in this paper. The method constructs a multilayer stacked fully connected neural network to optimize the seismic attributes predicted for the effective sand thickness of the reservoir layer by layer, and maps the optimized attributes directly to the sand thickness. We first analyze the influence of training samples on fully connected neural network modeling, and then compare the performance of the deep and shallow morphology of this network in the case of small samples when the model size is larger than the number of training samples and the model size is smaller than the number of training samples, and find that the deep network outperforms the shallow one when the training samples are small, provided that the number of training samples is larger than the model size. Finally, we apply the deep fully connected neural network to the effective sand body thickness prediction from real data of Shengli oilfield, and the application results show that the method achieves effective identification of sand bodies around 4 m in a tight sandstone reservoir, reflecting the ability of this end-to-end intelligent modeling method to mine latent geological information from seismic attributes, thus confirming its effectiveness in quantitative reservoir prediction.

A large number of Indosinian granites are widely developed in Guide basin, Qinghai Province, but there is a lack of research on their geochemical characteristics, petrogenesis and origin of granites. The resolution of these problems is very important to resolve formation background of indosinian granites in West Qinling. Therefore, LA-ICP-MS zircon U-Pb dating, whole-rock geochemistry and Lu-Hf isotope analysis of granodiorite from drilling hole ZR2 from Zhacanggou area, Guide basin were selected as research objects. Zircon U-Pb isotopic dating results show that the emplacement age of granodiorite is (225.3 ± 1.3) Ma, which is the characteristic of Late Triassic magmatic activity. Characteristics of major and trace elements show that granodiorite is a weak peraluminous, high-K calc-alkaline series rock, showing moderate Eu negative anomalies (δEu=0.59-0.91), enrichment of large ion lithophile elements (Rb, U) and depletion of high field strength elements (Nb,Ta,Ti). Zircon Hf isotopic composition shows that the εHf(t) values of granodiorite range from -7.70 to 0.22, and the corresponding two-stage model ages (TDM2) range from 1 747 to 1 243 Ma, indicating that the granodiorites in Zhacanggou area of Guide basin are the products of melting and mixing of lower crust and lithospheric mantle. Combined with the previous research results, it is considered that the granodiorite in the study area is a transitional tectonic system from syn-collision to post-collision extension after the closure of A’nimaqing-Mianlue Ocean.

In order to reveal the formation mechanism of the NE trending strike-slip faults in the north slope of Tazhong region, based on previous studies, this paper designed a structural physical simulation experiment platform by using the principle of similarity analysis, completed three sets of structural physical simulation comparison experiments, simulated the formation and evolution process, and analyzed the formation mechanism of the NE trending strike-slip faults in the north slope of Tazhong region.The results show that the NE trending strike-slip faults are controlled by the adjustment of pre-existing basement faults and thick mudstone (detachment zone) of the Upper Ordovician, and formed under the action of the surrounding tectonic activities. The NE trending strike-slip faults in Tazhong area experienced two stages of formation and resurrection, and were compressed by paleo-stresses from the southwest and southeast successively.

The Shalong iron formation located in the Central Tianshan block is one of the newly discovered Neoproterozoic iron formations. Previous studies have reported the deposit characteristics, formation age and tectonic settings of the Shalong iron formation, and discussed the genesis and sedimentary environment of the deposit on the base of the whole-rock element geochemistry and iron isotope analysis of the ore. However, there is little attention paid to micro-geochemical analysis of ore minerals in Shalong iron formation, which restricts the in-depth understanding of the iron mineral formation process and formation environment. This study focuses on the magnetite and hematite of the representative iron ores from the Shalong iron formation. Based on the detailed mineralogical study, in-situ geochemical analysis of magnetite and hematite using femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry (fs-LA-ICP-MS) was carried out, so as to further reveal the formation process and environment of magnetite and hematite. The hematite in the Shalong iron formation is mainly presented as subhedral micro-fine grained tabular texture, and distributed along the layer of rocks, the magnetite is presented as euhedral to subhedral granular. The results of the in-situ geochemical analysis show that magnetite has a high mass fraction of Si, Ca and Mn and a low mass fraction of Ni, Cu and Zn. The mass fraction of V  of magnetites from different samples  are relatively consistent, and the mass fractions of Ti vary greatly. Hematites have a higher mass fraction of Si, Ca, Ti,  Cr and a lower mass fraction of Mn, Ni and Zn than magnetites. The total rare earth elements in magnetite are low (w(ΣREY)=1.49×10-6-51.16×10-6, average 12.15×10-6), showing the characteristics of depletion in light REEs (LREEs) and enrichment in heavy REEs (HREEs), with no observed Eu anomalies and positive La anomalies. Magnetite and hematite in different samples have similar REE distribution patterns as those of the whole ore, indicating that magnetite and hematite in iron formation  are the main carriers of rare earth elements, and the trace element characteristics of magnetite and hematite can provide a new insight for revealing the source of ore-forming materials and redox conditions during the formation of iron formation. Our results, in conjunction with previous studies, suggest that the magnetite in the Shalong iron formation is the product of hematite recrystallization, and rare earth element characteristics of magnetites indicate that the Shalong iron formation has a source of mixed ore-forming materials of low-temperature hydrothermal solution and seawater, while the lack of Ce anomalies and the relatively consistent mass fraction of V and Cr indicate that the iron formation was formed in a relatively anoxic environment, and the changes in oxygen fugacity were small during the formation process.

 

In order to increase the retardance of soil-bentonite slurry wall backfill materials to pollutants, activated carbon was used to modify it. Through slump test and simulation column experiments, the influence of activated carbon (AC) addition on the workability, permeability and compatibility of soil-bentonite slurry wall were studied, and the effect law of AC addition on the permeability and compatibility was clarified. The results indicated that the water content required to achieve a target slump increased with the AC content. The hydraulic conductivities of soil-bentonite slurry wall materials with 2%-10% AC were less than 1.0×10-7   cm/s, which met the requirement of hydraulic conductivity of vertical cut-off wall. When the content of AC was less than 2%, the addition of AC had no effect on the compatibility of the barrier materials with phenol solution. With the increase of the amount of AC, the adverse effect of phenol solution on the barrier materials was intensified. When the content of AC increased to 10%, the AC modified soil-bentonite slurry wall wasn not suitable for phenol contaminated groundwater environment.

Karst rocky desertification is one of the serious ecological and environmental problems in Southwest China. As the inheritance and continuation of Landsat and SPOT (systeme probatoire d’observation de la terre) series satellite data, Sentinel data has better application prospect in ecological and environmental monitoring. By the traditional method, the Karst rocky desertification mapping extracted from Sentinel-2A is only at 20 m resolution and this method wastes the detailed information. In order to extract the Karst rocky desertification more accurately, this research constructs 10  m resolution rocky desertification index for rocky desertification mapping of Beimen River basin in Wenshan, Yunnan based on the characteristic of Sentinel-2A data and analyzes the geological causes. By comparing four fusion algorithms, à trous wavelet transform has the better effect than high pass filtering, principal component analysis and  Gram-Schmidt transform  in short-wave infrared band (B12). The results show that the 10 m  normalized differential rocky index (NDRI) and rock exposure rate (fr )  have good correlation with 20 m NDRI and fr (the correction coefficients are 0.90 and 0.81, respectively), and they can provide more information of different ground objects. It indicated that the 10 m resolution index of Sentinel-2A has better performance for Karst rocky desertification mapping in this study.  The geological causes analysis of Karst rocky desertification in  Beimen River basin shows that the Karst rocky desertification mainly consists of  potential Karst rocky desertification and light Karst rocky desertification, which account for  40.66% and 16.97% of the total  basin area.  Karst rocky desertification is distributed mostly in the Gejiu  Formation and Banna  Formation. Within slope range of 0°-25°, all types of Karst rocky desertification are concentrated development , accounting  for 82.71% of the total area of Karst rocky desertification. 

Gaobei felsic dikes are exposed in the middle of the Yushan metallogenic belt, south Jiangxi Province, intruding into the Precambrian metamorphic strata, and their rock type is mainly granite porphyry. In order to reveal the emplacement age, petrogenesis and relationship with mineralization in the Gaopi ore deposit in south Jiangxi Province, petrography, geochemistry, zircon U-Pb dating and Hf isotopic analyses were carried out on the Gaopi granite porphyry. The results show that the Gaobei granite porphyry is characterized by high silicon (74.53% on average), high potassium (4.34% on average) and aluminum-rich (15.36% on average), and belongs to the high-k calc-alkaline series or k-basalt series granite; It has a low Nb/Ta, Zr/Hf ratio, and the REE fractionation is not obvious with strong Eu negative anomaly, proving to be highly differentiated granites. Zircon LA-ICP-MS U-Pb data has yielded concordant age of (135.73±0.46) Ma (MSWD=1.7), and a mean age of (135.62±0.92) Ma (MSWD=0.27), indicating that the Gaobei granite porphyry was emplaced in Early Cretaceous. Zircon Hf isotope analysis results show that the 176Hf/177Hf=0.282322-0.282450, εHf（t）=-13.3--8.5, and the two-stage model age TDM2 varies from 2.03 Ga to 1.73 Ga, inferring that the Gaobei granite porphyry may be mainly derived from the melting of the Proterozoic crustal materials. The field investigations found that the surrounding rocks around the Gaobei ore deposit have undergone intense hydrothermal alterations such as argillization, beresitization, and silicification, and are distributed in a planar pattern. Meanwhile, the borehole has revealed net-vein molybdenum mineralization, inferring that the deep area has the potential for porphyry molybdenum deposits.

There are numerous Late Paleozoic acidic intrusive rocks in Wenquan area, which is located on the northern margin of the Yili block. In this paper, we present new zircon U-Pb geochronology, Lu-Hf isotopic and geochemical studies of the Early Devonian granites from Wenquan area, aiming to confirm their timing, discuss their petrogenesis, and explore their tectonic evolution process. The zircon LA-ICP-MS U-Pb age of the monzogranites is (418±7) Ma which indicates that their crystallization age is the product of Early Devonian magmatic activity. Meanwhile, the zircon Hf isotope compositions of the monzogranite are typically characterized by high εHf(t) values (8.2-14.0, with an average of 11.3), and the young two-stage model ages (TDM2=863-492 Ma), implying their derivation from a relatively juvenile crust. These two types of granites are characterized by high SiO2, weakly peraluminous, as well as low CaO and MgO contents. The trace elements of the granites are characterized by depletion in high field strength elements (Nb, Ti, P), and enrichment in large ion lithophile elements (K, Rb). The standardized distribution pattern of rare earth elements in chondrites is enriched in light rare earth elements and depleted in heavy rare earth elements, with significant negative Eu anomalies. The low zircon saturation temperature, negative correlation between P2O5 and SiO2, and other geochemical features suggest the granites are I-type granites. Several tectonic discrimination diagrams shows that they were formed in a continental magmatic arc setting. Combined with the regional tectonic background and the evolution information of magmatic rocks in the adjacent area, it is speculated that the granites were mainly derived from the crustal accretion in response to subduction of the Junggar-Balkhash Ocean. 

In order to study the law of hydrocarbon enrichment at the oil-source fault in the petroliferous basin, based on the study on the conditions and evolution stage of oil-source fault transport, the method of determining the evolution stage of oil-source fault transport is established by determining the activity period of oil-source fault and the formation period of the oil-source fault transport in the oil source and the oil source outside the oil transfer station. The method is used to determine the evolution stage of oil and gas transport from Nandagang fault to the Lower Member of the Shahejie Formation in Qikou sag, Bohai Bay basin. The results show that, the oil and gas stage of Nandagang fault to the Lower Member of the Shahejie Formation to the Third Member of the Shahejie internal transfer station starts from the deposition of Guantao Formation to the middle deposition of Minghuazhen Formation; The oil and gas stage of the transfer station of the third stage is from the middle deposition to the end of the Minghuazhen Formation. After two evolutionary stages, the oil and gas transporting period is relatively long, which is conducive to the large-scale accumulation and accumulation of oil and gas from the underlying source rocks of the Third Member of the Shahejie Formation in the Lower Member of the Shahejie Formation. According to the method of this paper, it can reasonably explain the phenomenon of oil and gas enrichment in the lower sub-member of the Nandagang fault. This method is suitable for determining the evolution stage of oil and gas transport by oil-source faults.

The volcanic rocks in the Yitong area of central Jilin Province are located in the eastern segment of the northern margin of the North China plate. This paper presents zircon LA-ICP-MS U-Pb geochronology and geochemical data of the volcanic rocks in this area, aiming to explore their petrogenesis. The zircons in the andesite present euhedral-subhedral, and obvious magmatic oscillation zone, with Th/U ratios of 0.06-0.95, indicating their magmatic origin. Zircon dating results indicate that basaltic andesites were formed at (285±2) Ma, the Early Permian. The rock assemblage of the Early Permian volcanic rocks is basaltic andesite and andesite. The SiO2 mass fraction of the samples is 51.29%-58.91%, and the Mg# values are 39-66, belonging to the tholeiitic series, relatively enriched in light rare earth elements (LREEs), large ion lithophile elements (LILEs), and depleted in high field strength elements (HFSEs). Comprehensive studies suggest that the Early Permian volcanic magma originated from the depleted mantle wedge metasomatized by subducting fluids, and was formed in the active continental margin environment of the southward subduction of the Paleo-Asian Ocean. Combined with regional research results, it is believed that the northern margin of the North China plate was under the southward subduction of the Paleo-Asian Ocean in the Early Permian.

Using Landsat 8 TIRS thermal infrared data, the surface temperature of Guide basin was identified by remote sensing through single window algorithm and split window algorithm, and the location of high temperature anomaly area was determined. Based on the formation conditions of dry hot rock, a multi information dry hot rock target prediction model including 12 factors, including strata, rock mass, faults, annular structure, linear structure, hydrothermal alteration anomaly, surface temperature anomaly, hot spring, geothermal drilling, regional gravity anomaly, regional aeromagnetic anomaly, and electromagnetic exploration information, was constructed, and the dry hot rock target in Guide basin was predicted. The results show that: 1) The Neogene, Triassic and Quaternary strata are the heat preservation covers of the dry hot rocks in Guide basin, the large NW trending Late Triassic intermediate acid concealed granite is the heat storage rock mass, the NNW trending Waligong Mountain deep fault and granite body are the heat conduction channels, the lower mantle asthenosphere heating and the partially molten layer heating are the main heat sources, and the rock radioactive heat generation is the superposition heat source. 2) The concealed rock mass prediction area, surface temperature anomaly area and hydrothermal alteration anomaly area in the basin all have the characteristics of distribution along the northwest southeast direction, and the distribution positions confirm each other. 3) According to the model, there is a large dry hot rock belt distributed along the northwest southeast direction in guide basin, with an area of about 820 km2. 

In order to determine the best well layout of groundwater source heat pump, to explore the variation characteristics of aquifer temperature field and the sensitivity of hydrogeological parameters. Based on the geothermal geological conditions and thermophysical parameters of the thermal reservoir, a three-dimensional water heat coupling numerical simulation model was constructed by using FEFLOW software in Xiaojiaying-Dongzhaotong groundwater source heat pump suitable area of Shijiazhuang. Under the pumping and irrigation capacity of 2 000 m3/d, the temperature field of aquifer with different well spacing, different well layout mode was simulated to explore the possibility of thermal breakthrough, and the sensitivity of thermal conductivity, permeability coefficient, porosity and other parameters of the temperature field were studied. The results showed that: 1) For the single pumping and double irrigation mode, Scheme C (the reinjection well was located at the downstream of the pumping well and the connecting line was perpendicular to the groundwater flow direction, and the two reinjection wells and the pumping well form an isosceles right triangle), the well layout scheme had the least impact on the temperature field of the aquifer and was the optimal scheme; 2) Under the single pumping and double irrigation mode, when the pumping and irrigation volume was 2 000 m3/d, the spacing of pumping and irrigation wells in Scheme C was set at 40-50 m, which was more reasonable; 3) In the process of pumping and irrigation, the temperature field was more sensitive to the change of permeability coefficient, but less sensitive to the change of porosity and thermal conductivity.

Supraglacial lake is an important part of the ice sheet hydrological system, which can reflect the characteristics of ice sheet surface meltwater and influence the polar climate and environmental changes. In this paper, a fine extraction method of the supraglacial lake by spectral information and morphology information in northern Greenland is proposed based on WorldView-2 images. Firstly, the ice surface water was segmented from ice with index of water body suitable for ice environment NDWIice and threshold. Then, the ice surface water is divided into three types: Independent supraglacial lake, independent supraglacial runoff and mixed area, by morphological rules. Finally, Fourier descriptor-assisted watershed algorithm is introduced to extract the ice lake. In order to verify the feasibility of the method, WorldView-2 image sequences of nine periods in one ablation period were selected for experiment. Compared with other automated methods and manual digitalization results, the extraction accuracy and integrity of the proposed method are higher than 90%, and the average error rate is lower than 0.2%, which shows obvious advantages.

Land use change affects the surface runoff, and analyzing its change law and driving force is helpful to realize the rational utilization of land resources and water resources. Taking the Suzi River basin in the upper reaches of Dahuofang Reservoir as the research object, this study evaluates the effects of climate factors, human factors and land use change on the water volume of Dahuofang Reservoir by using transfer matrix analysis and correlation analysis methods, and discusses the reasons for the increase of water area of the reservoir mainly from the perspective of land use. The results show that the area of reservoir water increased year by year from 2000 to 2020, and the two main land use changes were the increase of forest area and the decrease of farmland area, both of which had positive effects on the water yield of the basin. At the same time, climate change also had a positive effect on the increase of reservoir water quantity.

The Lufeng 22 subsag is a magmatic diapir reformed subsag in Dongsha uplift，Pearl River Mouth basin. In order to clarify the structural deformation characteristics and evolution process of such kind of subsag, the research reconstructed the evolution process of the study area based on the structural interpretation of seismic data, the analysis of residual stratum thickness, and the balanced profile technology. it is found that, The west slope and the east sub-depression of Lufeng 22 subsag was subjected to three stages of strong magmatic diapirism, and the most active diapri is in member 4 of Wenchang Formation. The effect of magma diapirism on the depression structure is mainly shown in three aspects. First, magma diapir destroyed the initial structural style of the subsag, caused the boundary fault to bend and even break, showed a characteristics of plane zoning; Second, the strong uplift of magma lead to the strong tilting of the strata, thus the gentle slope strata was greatly uplifted and subjected to strong denudation; Third, the magma diapir produced secondary bulge, which influenced the location, scale and evolution of the sedimentary center, thus showed a very complex structural characteristics and evolution process. The west slope and eastern subsag with strong magmatic diapirism only experienced evolution stages of fault-down thrown basin and faulted-sag basin, while the western subsag, high-in-sag and east slope with weak magmatic diapirism completely developed three evolution stages of fault-down thrown basin, faulted-sag basin and sag basin. The tectonic units showed lateral zoning characteristics.

During underground engineering construction in gypsum-enriched formations, the reaction between  gypsum and groundwater leads to the dissolution of Ca2+ and SO42-, which enhances the erosion effect on the concrete foundation of underground structures and affects the safety of underground engineering. In order to investigate the erosion characteristics and mechanisms of concrete under different  formation environmental conditions, commonly used C20 and C30 concrete in underground engineering construction were studied. The study focused on the gypsum-containing formation  conditions in the southern part of Chengdu basin and explored the erosion characteristics and mechanisms of concrete in both gypsum-containing and non-gypsum-containing formations under changing underground temperature conditions. The results show that: 1) The erosion degree of C20 and C30 concrete in gypsum-containing formations is significantly greater than in non-gypsum-containing formations. Under the erosionby different geological groundwater, the  maximum mass change rates of C20 and C30 concrete are 1.80% and 0.87%, with the maximum compressive strength reduction rates of 20.14% and 12.80%, respectively. C30 concrete exhibits a smaller attenuation in compressive strength under different groundwater conditions, making it more suitable as a construction material for underground engineering. 2) Increasing temperature enhances the erosion effect of SO42- on concrete, leading to a decrease in compressive strength. Among them, the maximum compressive strength reduction rates of C20 concrete under Quaternary and Guankou  Formation groundwater erosion reach 6.89% and 3.89%, respectively. 3) Concrete erosion occurs from the outside to the inside, where Ca2+ and SO42- in groundwater recrystallize to form gypsum on the  external surfaces of the concrete and then diffuse along cracks towards the interior, resulting in the formation of ettringite crystals, expansion forces, crack formation, and a decrease in compressive strength. Through correlation analysis, a relationship equation between the mechanical properties of concrete and temperature was established, achieving quantitative calculation of long-term changes in the mechanical properties of concrete in gypsum-containing formation engineering construction.

The Qitaihe fault depression in the Boli basin is rich in coalbed methane resources, but the exploration level is low, and the understanding of the enrichment and accumulation laws and mechanisms is insufficient, which restricts exploration practice. Based on a detailed dissection of the geological conditions of coalbed methane in the Qitaihe fault depression, this article reveals the enrichment characteristics and reservoir formation mechanism of coalbed methane in the study area. The study found that the coalbed methane reservoir in the Qitaihe fault depression has good conditions, with many coal seams in the Lower Cretaceous Chengzihe Formation, a large total thickness of coal seams, multiple developed coal rich centers, and a high degree of thermal evolution. The physical properties of coal reservoirs are favorable, and the gas content of coal seams is generally characterized by high in the west and low in the east. The structure, the hydrology,  the sealing and other preservation conditions benefit coalbed methane reservoir formation. There are three types of models of coalbed methane reservoir formation, syncline-hydraulic sealing, fault sealing-hydraulic sealing, and fault-multi seam self-sealing. Under moderate burial depth and slow stagnant water environment, the reverse fault sealing area, secondary structural high point, and middle coal seam stratification are favorable locations for coalbed methane enrichment. On this basis, a multi-level fuzzy mathematics evaluation model for coalbed methane selection was established, and favorable areas were evaluated. Seven coalbed methane favorable areas were selected, including Qinglongshan-Taoshan district and Machang district.

 In Northeast China, snowmelt is an important source of spring runoff, and the reliable simulation and forecasting of snowmelt runoff can provide a reference for reasonable management and scheduling of water resources during the spring flood season. There are two runoff-generating models of snowmelt runoff and rainfall runoff in the cold Northeast region during the year. The differences in the physical and spatial properties of the basin have a significant impact on the snowmelt runoff generation. To solve the problem of spatial heterogeneity of snowmelt runoff, and to improve the simulation and forecasting accuracy of the SWAT model, we propose a single-site and multi-site combined parameter calibration for the SWAT model. Firstly, the initial parameter calibration of single station was carried out by using the inflow of Baishan Reservoir, and then the snowmelt runoff parameters were calibrated by multi-station, and the parameters were transplanted to the initial parameter set of single station. The correlation coefficients (R2) of monthly average flow in validation periods of the annual (January-December), flood season (June-September), and spring season (March-May) were 0.76, 0.74, and 0.58, the daily average flow R2 were 0.71, 0.75 and 0.51, after the initial parameter rate determination at a single station. The correlation coefficients R2 in validation periods of the annual (January-December), flood season (June-September), and spring season (March-May) were 0.80, 0.74 and 0.79, the daily average flow R2 were 0.74, 0.78 and 0.61, after using a combined single-site and multi-site parameter calibration strategy. The results showed that the simulation accuracy of snowmelt runoff was improved by 20% and 10% respectively.

Abstract： To carry out engineering geological evaluation of hydraulic reclamation areas such as Chongming Dongtan, this paper aims at the change in shear strength of the underlying clayey soil layers in Chongming Dongtan. Considering different reclamation times, soil samples from boreholes in five different reclamation areas (within the 1949 cofferdam, 1949-1964, 1964-1976, 1976-1990, and 1990-1998) were selected for direct shear tests, and the variation of shear strength of soils in different periods and layers were analyzed.  Moreover, the microstructure of the soil samples was observed by scanning electron microscopy, and the change in shear strength was analyzed qualitatively and quantitatively from a microscopic perspective. The results revealed that: 1) The shear strength of the clayey layer varied as， the clay layer in the 1949-1964 reclamation zone had the largestshear strength, and the peak shear stress at 50, 100, 200, and 300 kPa is 33.31, 46.68, 102.10 and 147.15 kPa, respectively. Little difference in shear strength between boreholes in silty clay layer was observed under various levels of vertical pressure. From west to east, the shear strength indexes of the clay layer showed an opposite trend to that of the silty clay layer, in relation to the trend in natural water content. 2) From west to east, significant changes in the microstructure of the soil samples were observed. The soil microstructure in clay layer changed from a flocculent/aggregate to a matrix structure， and the soil microstructure in silty clay layer gradually transitioned from a skeletal/aggregate structure to a matrix structure and to a flocculent/aggregate structure. 3)  The average pore diameter of the particle was negatively related to the cohesion and positively related to internal friction angle. In addition, the average shape coefficient of the particle was positively related to the cohesion and negatively related to internal friction angle. This indicated that average pore diameter  and the average shape coefficient of the particles were directly related to the shear strength indexes of the soil.