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.

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.

 It is of great significance for the efficient development of sandy braided river reservoirs to clarify the different characteristics and genesis of the same level architecture elements. Based on modern deposit, field outcrop, and core, the quantitative architecture characterization was carried out in typical layers by taking the sandy braided river of lower He8 Member in Sulige gasfield as the study subject. Architecture differences were emphatically compared from the fifth to third level in typical layers of H8x2-2, H8x1-3, and H8x1-1. Influenced by source condition and base level change, the braided belt scale of lower He8 Member changes from 650.0 m to 1 750.0 m. The single braided belt has three different distribution patterns: Isolated type, lateral splicing type, and vertical superposition type. Architecture differences in individual sandbody are remarkably affected by flooding, channel erosion, and chute scour. The scale of braided river bar is greater with an average thickness of 7.2 m in the layer of advantage lithofacies probability higher than 80%. The average length and width are 1 402.0 m and 809.0 m in H8x2-2. The architecture differences of the third level are minor in braided bar. Falling-silt layers have the similar feature of thin, gentle and lenticular distribution. They are 0.1-0.4 m thick and with a dip angle of 1-3 degrees. Single lateral accretions are 360.0-565.0 m wide. The number of lateral accretions and the single size control the difference in the average bar scale in every layer. With the constraint of architecture differences in different levels, a three-dimensional geological model is built up to accurately reflect the distribution of sandy braided river architecture in Sulige gasfield, which can provide a reference for later development adjustment of the reservoir.

In order to reveal the characteristics and genesis mechanism of the deep reservoir in Lufeng sag of Pearl River Mouth basin, this study systematically analyzed the influence of sedimentary environment, abnormal pressure, geothermal gradient, and hydrocarbons charging on the anti-compaction ability of reservoir. The results show that the Paleogene reservoirs with a buried depth of more than 4 000 m in Lufeng sag are still featured by primary pores. The mineral composition of the reservoir is mainly quartz sandstone, and the overall performance is low-medium permeability reservoir. The underwater distributary channel of braided river delta has stable flow action. The long distance transport makes the grain size distribution of rock more uniform and the integral number of mixed matrix less, which are favorable conditions for the development of primary pores. The abnormal pressure formed by mudstone undercompaction transferred to sandstone reservoir can effectively reduce the damage of compaction to pore space. The plasticity and ductility of rock are relatively weak under low geothermal gradient, which slows down the compaction rate of rock. In addition, the oil and gas generated from the source rocks of the fourth member of Wenchang Formation occupied the reservoir space after entering the reservoir, which effectively inhibited the damage of the later compaction and cementation to the reservoir pores. Under the coupling control of four controlling factors, the primary pores of deep reservoir in Lufeng sag are widely developed.

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.

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.

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.

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.

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.

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 study the variation of soil pressure in the process of jacked pile penetration. A model test of jacked pile driving in saturated clay was carried out. The double-wall model pipe pile was used to separate the internal and external friction resistance, and a micro-soil pressure sensor was installed on the pile to monitor the soil pressure at the pile-soil interface. The variation law of pile pressure and pile tip resistance in pile driving process was analyzed. The distribution characteristics of soil pressure at the pile-soil interface in the process of pile sinking under static pressure were discussed. It was clear that the soil pressure at the pile-soil interface had obvious degradation effect in the process of pile driving. The change mechanism of soil pressure at the pile-soil interface during the process of pile sinking in saturated clay was revealed. The test results showed that the pile compression force increased linearly with the penetration depth, and the pile compression force of the closed pile was obviously larger than that of the open pile in the later period of penetration. The pile tip resistance increased linearly, accounting for 62.3% of the pile pressure in the process of piling. The soil pressure at the pile-soil interface increased at a low rate at the initial stage of the static pile penetration, but increased linearly and at a high rate with the gradual penetration of the static pile. At the same depth, with the gradual penetration of the static pile into the pile-soil interface, there was an obvious phenomenon of earth pressure degradation. The research results could provide reference for the study of soil pressure at the interface between piles and soil under static pressure. At the depth of 20, 30, 40, 50, 60 and 70 cm, the earth pressure degraded by 14.6%, 13.8%, 13.2%, 9.2%, 7.2% and 6.1% on average.

The dynamic strength and deformation characteristics of gravelly soils are the basis for analyzing the seismic permanent deformation of gravelly soil foundation and their structures. Therefore, a series of undrained cyclic triaxial tests on two kinds of gravelly soils were performed by use of a large dynamic triaxial apparatus in this paper. The effects of cyclic stress ratio, mean consolidation stress, consolidation stress ratio, initial void ratio and number of loading cycles on the deformation and excess pore pressure characteristics of gravelly soils were investigated in detail. The test results showed that the cumulative axial strain and excess pore pressure ratio of gravelly soils increased with the increase of cyclic stress ratio, mean consolidation stress and initial void ratio, and the excess pore pressure ratio decreased with the increase of consolidation stress ratio. When the number of loading cycles was less than 20, the consolidation stress ratio had little influence on the cumulative axial strain. When the number of loading cycles was more than 20, the cumulative axial strain decreased with the increase of consolidation stress ratio. Based on the test results, the empirical models of undrained dynamic strength and excess pore pressure were proposed in which the effects of mean consolidation stress, initial void ratio, number of loading cycles, and cumulative axial strain were taken into account. Comparisons of the computed values by models with the measured ones by tests showed that the proposed models could accurately describe variations in undrained dynamic strength, excess pore pressure and cumulative deformation for two kinds of gravelly soils under cyclic loading.

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.

 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.

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.

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.

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.

In marine seismic exploration, the severe seabed undulation and velocity difference have great influence on the kinematic and dynamic characteristics of reflected waves in the underlying strata. In this paper, submarine steep slope model, submarine depression model, submarine uplift model and submarine volcano model are established for the rugged seabed, and the effects of rugged seabed on the reflection wave characteristics of the underlying horizontal strata are studied by the optimized eight-order finite difference method and the optimized four-order Runge-Kutt (RK) method under the staggered grid simulation. Numerical examples show that submarine steep slope, submarine depression and submarine uplift not only distort the reflected waves and converted waves of the underlying horizontal strata, but also affect the energy distribution of the reflected waves, thus easily causing the structural illusion. Submarine volcano causes more complex distortion of reflected and converted waves from the underlying horizontal strata, which brings difficulties to the data processing and interpretation in marine seismic exploration.

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.

The characteristics of conventional logging curves under different fracture scales were analyzed, the logging curve classification methods of Class Ⅰ (well diameter expansion ratio >18%, deep resistivity < 20 Ω·m, interval transit time >260 μs/m, density <2.4 g/cm3), Class Ⅱ(well diameter slightly expanded, deep resistivity <30 Ω·m, interval transit time > 235 μs/m, density < 2.55 g/cm3), and Class Ⅲ (no significant changes in well diameter expansion, deep resistivity, interval transit time and density) fracture scales were established, and the fuzzy identification sample space was constructed on the basis of considering the fracture scale, and the membership degree function and equation of whether the reservoir capacity of the extended formation of Honghe oilfield was low or high production was determined. If the low yield degree of membership is greater than or equal to the high yield degree of membership, it is a low yield oil layer, otherwise it is a high yield oil layer.After the identification verification of 20 oil layers, the accuracy rate of this model is 85%, and a good identification effect has been achieved.

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.