Addressing the challenge posed by the uneven distribution of various features and the low classification accuracy of urban remote sensing images, we propose a novel method for remote sensing image classification that integrates parallel attention and weight balance algorithm. Leveraging the semantic segmentation network architecture of DeepLabV3+ and ResNet50, our method combines channel attention and spatial attention algorithms in parallel to improve the network's feature extraction capability. Additionally, to address the issue of imbalanced feature category proportions in remote sensing images, we propose a feature category weight balance algorithm to improve the classification accuracy of minority feature categories. To validate the effectiveness of our network model for classification, we conduct experiments using Vaihingen and Postdam datasets. The experimental results demonstrate promising performance metrics: The remote sensing image classification algorithm that integrates attention mechanism and weight balance is validated in the Vaihingen dataset with pixel accuracy, mean intersection over union, and mean F1 values of 96.66%, 90.35%, and 96.66%, respectively. In the Postdam dataset, the pixel accuracy, mean intersection over union, and mean F1 values of the validated data are 95.74%, 81.47%, and 91.82%, respectively. From the classification details, incorporating an attention mechanism and a weight balance algorithm significantly enhances the recognition accuracy of cars, which account for a relatively small proportion. Specifically, the pixel accuracy of cars in Vaihingen dataset has improved by 26.44%, and in  Postdam dataset, it has increased by 21.84%, leading to commendable classification results.

 The pilot demonstration area of Well MH1 in the northwest margin of  Junggar basin (MH1 well  area) exhibits fractures of varying scales in the Permian and Triassic formations. The formation mechanism of these fractures is complex, the subsequent stimulation is frequent, and the existing forms are various, which seriously restrict the development process of horizontal wells. Based on improving the signal-to-noise ratio and resolution of seismic data, this paper establishes the small-scale hidden fault identification process and model, and further guides horizontal well drilling through a combination of optimal azimuth superposition scheme, continuous wavelet transform seismic data frequency boosting, matrix singular value decomposition for denoising, iterative processing of structure-guided filtering, fracture enhancement filtering, multi-attribute fusion, and artificial intelligence (AI)-based fault recognition. The results show that by combining various geophysical methods with AI technology, this paper establishes a small-scale concealed fault identification process and model suitable for MH1 well area, significantly improves the fault identification accuracy, optimizes the drilling trajectory of horizontal wells in MH1 well area, successfully avoids high-risk fault zones, reduces the incidence of leakage events by about 20%, and reduces the problem of pressure and channel interference by about 15%.

Numerical simulation of seismic wave fields is crucial for seismic exploration, seismic data processing, and the study of Earth’s structures. The wave equation numerical simulation method takes into account the dynamic and geometric characteristics of seismic wave propagation, providing a solid theoretical basis for studying the mechanism of seismic wave propagation and interpreting complex geological structures. It is currently one of the most widely used methods for simulating seismic wave fields. This article surveys five wave equation-based numerical simulation methods: The finite difference method is easy to understand, but suffers from numerical dispersion issues; The pseudo spectral method offers high accuracy but low efficiency; The finite element method is suitable for complex models but requires substantial computational resources; The spectral element method is appropriate for high-precision problems but demands significant computational memory; And the deep learning method based on physics-informed neural networks demonstrates strong adaptability, though it comes with high training costs. The theoretical foundations, applicable conditions, and latest advancements of these five numerical simulation methods are described respectively. In the future, seismic wave field numerical simulation methods should integrate cutting-edge technologies such as deep learning, optimize boundary conditions to simulate actual boundary reflections, and enhance the precision and efficiency of simulations.

Fine reservoir description has always been the focus of development and production of unconventional oil and gas resources, but the vertical resolution of conventional logging curves is difficult to satisfy the effective identification of thin layers at centimeter or even millimeter scale. Aiming at this problem, this paper proposes a two-level knowledge migration super-resolution method for large-scale difference in logging curves to improve the vertical resolution of logging curves, thus realizing high-resolution target reservoir fine description in low-cost cases, using integrated machine learning as the basic tool and the perspective of multi-view and multi-scale as the core. The microsphere resistivity, natural gamma ray, and acoustic time difference curves with better formation response are selected as the target curves, and the construction of a mapping model from the information of high-resolution imaging resistivity curves to the target logging curves is realized, which in turn realizes the large-scale difference super-resolution of target logging curves , and the super-resolution results are compared with different super-resolution methods. The results show that the correlation coefficients between the super-resolution curves obtained by the method of this paper and the real high-resolution curves are greater than 0.9, which are improved by 3.6% to 16.0% compared with the comparison methods, and the mean square error,the root mean square error, the mean absolute error, the mean absolute percentage error, the symmetric mean absolute percentage error  are reduced by 28.9% to 90.8%, 15.7% to 69.8%, 24.4% to 74.7%,  25.0% to 74.2%, and 25.2% to 77.4% , respectively. Therefore, the method of this paper is able to largely realize the millimeter-level super-resolution processing of the existing conventional logging curves, and the obtained super-resolution curves are able to roughly capture the formation changes, which alleviates the difficulty of the problem of effective identification of fine reservoirs.

The traditional spectral blueing frequency broadening methods have a limitation in the calculation of spectral blueing operators, leading to poor effects when applied to post-stack seismic frequency enhancement. To address this, a frequency-division spectral blueing broadening technique based on matching pursuit is proposed. Firstly, the matching pursuit method is employed to accurately divide the post-stack seismic data into multiple frequency-split seismic bodies. Then, during the calculation of the spectral blueing operators for each frequency band, a weighting approach is introduced to determine the weights of the optimized spectral blueing operators for each frequency band based on the differences in energy across different frequency bands. Finally, the optimized spectral blueing operators are convolved with seismic reflection coefficients to obtain high-resolution seismic data. Actual tests on post-stack seismic data demonstrate that, compared with traditional spectral blueing methods, the frequency enhancement method proposed in this paper improves the high-frequency component information of post-stack seismic data. After frequency expansion, there are more seismic event axes and  the  resolution is higher. Through a series of operations such as attribute extraction, well seismic calibration, and inversion of the seismic data before and after processing, it is verified that the high-frequency components of the frequency-enhanced seismic data are effective and can more accurately delineate faults and identify thin-layer sand bodies.

Fractured reservoir is a kind of fluid-bearing fracture-porous medium, and the quantitative characterization of fracture parameters plays a critical role in the exploration and development of unconventional hydrocarbon reservoirs. However, conventional reservoir prediction methods primarily based on amplitude information are limited in revealing the complex characteristics of fractured reservoirs. This paper focuses on fluid-saturated orthogonal fractured reservoirs and thoroughly analyzes the velocity dispersion and attenuation characteristics of media containing both horizontal and vertical orthogonal fractures. An anisotropic reflectivity method is employed to simulate the frequency-dependent amplitude variation with offset (AVO) response of a single-interface dispersive sandstone reservoir. Based on this, a Bayesian inversion framework driven by the responses of horizontal and vertical orthogonal fracture models is developed to achieve multi-parameter quantitative inversion of porosity, fracture density, and fracture radius in fractured reservoirs. The results demonstrate that porosity, fracture density, and fracture radius are highly sensitive to velocity dispersion. At low frequencies, the frequency-dependent PP wave reflection coefficient exhibits significant variations with both frequency and incidence angle, and the amplitude increases linearly with the incidence angle. This highlights the substantial influence of fracture parameters on the frequency-dependent AVO response. Inversion results show that the proposed method achieves high accuracy in posterior probability distributions under varying fracture parameter conditions, with particularly improved applicability and reliability in predicting fracture radius in small-scale fractured reservoirs.

The study of well log cyclostratigraphy is mainly based on the Milankovitch astronomical theory, using logging data as a proxy for astronomical cycles to investigate scientific issues in geology, environment, climate, and other fields. Currently, there is still a lack of specialized software for the processing and analysis of well log cyclostratigraphy both domestically and internationally. In this paper, a well log cyclostratigraphy analysis module is developed using Java language based on the CIFLog software, which includes necessary functions such as preprocessing, astronomical testing, filtering and tuning. The effectiveness of each function is verified using theoretical curves as test data. We select the Th content data from natural gamma ray spectroscopy  logging of  Qingshankou Formation in Well SK-2 in  Songliao basin for processing and successfully identify and extract 13 long eccentricity signals. The sedimentation rate is estimated to be 5.6 cm/ka, and a floating astronomical time scale has been  established.

 As a material and energy exchange process between deep fluids and shallow depositional systems, hydrothermal activity exerts a crucial control on depositional environments, diagenesis, and organic matter enrichment, and shows significant spatial-temporal distribution in typical petroliferous basins of China. Based on mineralogical, lithological, and elemental-isotopic evidence, this study systematically summarizes and identifies hydrothermal mineral assemblages (e.g., dolomite, pyrite, and authigenic quartz) and geochemical fingerprints (e.g., enrichment of Fe, Mn, and light rare earth elements, Eu anomalies, and low δ18O values), and further outlines characteristic lithologic associations (e.g., siliceous rock-black shale and carbonate-organic matter interbeds). Within a regional comparative and multi-proxy framework, the geological records and paleoenvironmental changes related to hydrothermal activity in sedimentary basins are synthesized. Hydrothermal fluids alter redox gradients, supply nutrients (N, P, Fe, Si, etc.), and regulate temperature-salinity structures and water column stratification, thereby modifying salinity and local carbon cycling, which indirectly or directly affect primary productivity and organic matter preservation. Overall, hydrothermal activity exerts a dual “promotion-inhibition” effect on organic matter enrichment, with the final outcome controlled by multiple factors including temperature, fluid composition, and tectonic setting. Therefore, exploring the spatial-temporal distribution and environmental impacts of hydrothermal activity can improve our understanding of source rock formation and evolution, and provide a scientific basis for hydrocarbon potential assessment.

Globally, granite buried-hill oil and gas reservoirs have been revealed in 25 basins across 17 countries, with proven reserves exceeding 3 billion tons of oil equivalent. In China’s basins, proven reserves exceed 1.5 billion tons of oil equivalent. Granite has become an important target for oil and gas exploration in China, and rich achievements have been made in reservoir space types, rock physical properties, reservoir distribution patterns and genesis. Studies show that there are 7 categories and 12 types of reservoir spaces, mostly secondary pores and secondary fractures, with a small number of vesicles. The characteristics of reservoir space types vary among different oil and gas reservoirs. Granite buried-hill reservoirs are mainly of low to ultra-low porosity and medium to low permeability. The weathering crust thickness mostly ranges between 40 and 280 meters. The physical properties of granite buried-hill reservoirs decrease with increasing distance from the top of the weathering crust, though in rare cases, high porosity zones also exist at depth. Most oil layers/suspected oil layers/gas layers/oil-bearing water layers/gas-bearing water layers are distributed within about 200 meters to the top of the weathering crust, mostly concentrated within 150 meters. Granite buried-hill reservoirs exhibit zonation: The residual zone and weathering dissolution zone are mainly porous, the weathering fracture zone is mainly porous-fractured, and the bedrock zone is mainly fractured. Structural fractures exhibit a “sweet spot” distribution pattern. Parameters such as uniaxial compressive strength, permeability, and chemical alteration index can be used to establish quantitative relationships for the vertical zonation of the weathering crust. The reservoir formation mechanisms are mainly tectonic activity, weathering, erosion, and burial dissolution. Rock mechanics test results indicate that favorable internal conditions for fracture formation include coarse-grained crystals, high quartz and potassium feldspar content, etc.. Favorable external conditions include rapid cooling processes of the rock, and strong stress transformation during surface exposure. Weathering can form abundant weathering intergranular pores, weathering fractures, mold pores, sieve-like pores, intragranular micropores, and dissolution fractures in the residual zone and weathering dissolution zone. Erosion affects the preservation of the residual zone and weathering dissolution zone. A gentle slope on the top surface of the buried-hill favors the preservation of the residual zone and weathering dissolution zone. Burial dissolution can further expand pre-existing dissolution pores and fractures, promoting the development of inner reservoir zones in the bedrock zone. It is pointed out that inner reservoirs are more developed in the basin subsidence center areas. The porosity evolution of the reservoir at the top of the residual zone and weathering dissolution layer under compaction conditions follows a modified Athy formula. The average particle size and plagioclase content are negatively correlated with the porosity reduction amount while the chemical alteration index is positively correlated with the porosity reduction amount. Differences in rock fabric and the coupling relationship between the buried-hill uplift process and tectonic stress action result in differential fracture effects in buried-hills. In summary, favorable exploration areas for granite buried-hills are identified as regions with coarse grains, high quartz content, high potassium feldspar content, rapid exhumation, gentle slope surface, proximity to the basin subsidence center, and strong late tectonic modification. 

 Land subsidence risk inducing factors are complex and spatial distribution varies greatly, in order to scientifically carry out land subsidence risk assessment, this paper proposes the raster information quantity method for the evaluation of land subsidence risk. Firstly, the information value between each rasterized evaluation index and surface variables is calculated to quantitatively characterize the strength of the association between the influencing factors and the risk of land subsidence; Then, an evaluation system with 11 indexes is constructed, including hazard, vulnerability, and exposure; Then, the subjective-objective comprehensive weighting method is used to determine the weights and calculate the risk value, and the risk evaluation is carried out through the reliability test of the working characteristic curve of the subjects; Finally, the above methods were applied to the risk evaluation of land subsidence in Cangzhou City, Hebei Province, in 2022. The results show that the raster informativeness values of the hazard and exposure evaluation indicators are high compared to the vulnerability evaluation indicators. Among the hazard evaluation indicators, the annual average land subsidence rate is a high-risk indicator, and when the annual average land subsidence rate is -127--17 mm/a, the informativeness value is 1.538, which is the most hazardous for the risk of land subsidence; Among the exposure evaluation indicators, the population density is a high-risk indicator, and when the population density is >5 430 people/km2, the informativeness value is 1.923, which is the most hazardous for the risk of land subsidence. At 1 km spatial resolution, the area proportions of land subsidence risk levels in Cangzhou City are distributed as follows: 9.90% high risk, 24.91% relatively high risk, 31.12% medium risk, 23.05% relatively low risk, and 11.02% low risk; The high-risk areas were mainly concentrated in the main urban area of Cangzhou City, Suning County, Huanghua City and other areas, and the medium-risk areas were mainly distributed in the western area of Cangzhou City; The reliability of the raster information quantity method to evaluate the risk of land subsidence in Cangzhou City is good, and the accuracy reaches 0.714.

The Hexi area is the main emergency groundwater source for Xiangtan City, Hunan Province, ensuring the urban water supply safety demand. Identifying the spatio-temporal evolution process of water supply hydrochemical components under the long-term influence of climate change and human activities has important practical guiding significance for the local development and utilization of groundwater resources and pollution control. In order to quantitatively reveal the evolution processes of karst hydrochemistry under long-term controls of precipitation and human activities, as well as the spatio-temporal distribution and evolution patterns of hydrogeochemical characteristics in the karst areas of Southern China, this study applies multivariate statistical analysis, geostatistical analysis, hydrochemical methods，and Piper diagrams, Gibbs models, and major ion ratios to analyze the spatio-temporal variation patterns and influencing factors of karst hydrochemistry in the study area, based on national groundwater quality monitoring data (2002—2021). The results show that: The karst hydrochemistry in the study area exhibits horizontal zonation in space, which can be divided into Hydrochemical Zone Ⅰ and Hydrochemical Zone Ⅱ. Along the overall flow direction of karst water from Zone Ⅰ to Zone Ⅱ, the hydrochemical components show a “positive increase”. The concentration of karst water chemical components has shown a phased change on the annual time scale over the past 20 years, with the overall evolution process being “stationary-rising-declining-stationary”. The key time nodes are 2007, 2011, and 2017. The spatial differences in karst hydrochemistry are mainly influenced by human activities. On the one hand, agricultural non-point source pollution and urban domestic sewage enter the aquifer through surface infiltration, increasing the concentration of some components in Zone Ⅱ; On the other hand, artificial groundwater exploitation alters the local karst water flow field, causing hydrochemical components within the study area to exhibit “reverse change” characteristics along the overall flow direction of karst water. The evolution process of karst hydrochemistry on the annual time scale is influenced by changes in annual precipitation, and the influence time can be traced back to 2-3 years ago. This study comprehensively applied mathematical and chemical methods to quantitatively reveal the evolution process of karst hydrochemistry under the long-term control of precipitation conditions and human activities, which can provide reference for analyzing the spatio-temporal distribution and evolution law of hydrogeochemistry in karst areas of Southern China.

During paleoclimate analysis using sediment chromaticity, some intermediate tools are always dependent and the results are usually indirect or general. Coupling relationship study of the modern sediment chromaticity and its corresponding climate parameters can find direct climate indication of the chromaticity parameters, which is helpful to promote the chromaticity application in paleoclimate research. In this paper, 210Pb dating is used for Xinfa Reservoir Inner Mongolia sediments. Combined with the local corresponding meteorological data, the sediment chromaticity and meteorological data are statistically analyzed. Four types of sediment chromaticity-climate parameter models were found in the northern section of the Greater Khingan Mountains between 1965 and 2022. Type Ⅰ, brightness negatively indicates the average annual precipitation, redness and yellowness positively indicate the average annual temperature, which corresponds to rainless cold and gentle breeze character. Type Ⅱ, brightness negatively indicates the average annual precipitation, and positively indicates the wind speed; The redness and yellowness are negatively indicating the average annual temperature, which corresponds to rainy chilly and gentler breeze. Type Ⅲ, the brightness and yellowness negatively indicate the average annual precipitation, and the redness is weak as climate indicator, which corresponds to a temperate rainy and moderate breeze climate. Type Ⅳ, brightness negatively indicates the average annual precipitation, redness and yellowness positively indicate the average annual wind speed, which corresponds to temperate rainy and more gentle and more light-gentle breeze. Among these models, brightness is mainly influenced by precipitation, redness is mainly influenced by evaporation, and yellowness is much complex.

The different micro pore throat structure characteristics of tight reservoirs lead to different permeability and corresponding development strategies. Taking the Chang 6 reservoir in the Jiyuan area of the Ordos basin as an example, this study comprehensively analyzes the pore throat structure, connectivity, and fluid mobility of the tight reservoir using analysis and testing methods such as casting thin sections, scanning electron microscopy, constant velocity mercury injection, nuclear magnetic resonance, and computed tomography (CT). The study also uses core multiphase permeability experiments and real core visualization microscopic permeability experiments to study the permeability characteristics of different types of pore throat structures. Research has shown that the average porosity of the Chang 6 reservoir in the Jiyuan area is 12.1%, with an average permeability of 0.48×10-3μm2. The reservoir pore types are mainly intergranular pores, followed by feldspar dissolution pores, and are accompanied by a small amount of intercrystal pores and rock debris dissolution pores. According to the physical properties and pore throat structure characteristics of the reservoir, the pore throat structure types of the Chang 6 reservoir can be divided into three categories. Among them, Type Ⅰ is mainly composed of intergranular pores, supplemented by feldspar dissolution pores, with well-developed pores and good connectivity between throats. The movable space is developed, and the microseepage is mainly uniform. Type Ⅱ reservoirs are still dominated by intergranular pores, followed by feldspar dissolution pores. However, the proportion of intergranular pores in Type Ⅱ reservoirs decreases, while the proportion of dissolution pores increases, and the pore throat radius decreases compared to Type Ⅰ reservoirs. The connected pore structures are sparsely clustered and connected, with more developed movable spaces. Microseepage is mainly network-like. The pore types of Type Ⅲ reservoirs are mainly feldspar dissolution pores, followed by intergranular pores. The proportion of intercrystal pores increases, and the throat connectivity between effective pore reservoirs is poor. The three-dimensional pore structure space shows strong heterogeneity, and the movable space is not developed. Microseepage is mainly finger-shaped. The comprehensive analysis between macroseepage methods and microscopic pore throat structures shows that reservoir physical properties, pore throat combination methods, and degree of throat development determine different types of seepage methods. Reservoirs with good physical properties and well-developed throats have better water flooding effects, thereby improving the final recovery efficiency.

Halk Mountains are situated in the northern Tianshan range. Their complex geological structure and intense topographic dissection have resulted in well-developed fractures and well-developed fissures within river valleys. This area significantly impacts the overall water resources and ecological environment of the northern Tianshan piedmont. To evaluate groundwater infiltration capacity in this region and explore the permeability characteristics of bedrock fractures in Halk Mountains area, this study proposes a coupled simulation method of discrete fracture-equivalent continuous medium based on the theoretical foundations of discrete fracture network (DFN) model and equivalent continuous medium (ECM) model. Firstly it analyzes the spatial characteristics of regional fissures by integrating the hydrogeological background and natural fissure network characteristics, then performs discrete fissure network simulation according to the natural fissure network characteristics to establish a discrete fissure network model consistent with the regional actual geological conditions, and finally achieves fissure-geological unit coupling based on the equivalent medium model theory to calculate the equivalent permeability of the fissure network. The results indicate that: Fractures in the study area are influenced by Halk Mountain fault structure, with an overall strike predominantly NWW and NEE; The fissure widths follow a log-normal distribution, and the spatial distribution of fissures adheres to a Fisher distribution; The equivalent radius of the fissures ranges from 312.9-780.6 m, the fissure width spans 1.43-25.19 mm, the permeability varies from 2.3-66.7 mD, and the fissure density ranges from 0.10-5.25 m^-1; The equivalent permeability values are 0.050-1.877 mD in the xx direction, 0.050-1.947 mD in the yy direction, and 0.100-2.825 mD in the zz direction, with the permeability of the entire region being less than 3 mD. The bedrock fissure network in Halk Mountains area exhibits relatively low permeability, with fault zones and river valley fissure development zones serving as the primary pathways for groundwater flow in the mountainous region. Comparing the simulation results with previously conducted hydrogeological test results shows good agreement, validating the reliability of the coupled discrete fracture-equivalent continuum simulation method.

In order to determine the shale oil resource potential of Da’anzhai Member, Jurassic Ziliujing Formation of Sichuan basin, the hydrocarbon generation potential, reservoir property, oil content, and shale oil mobility conditions were comprehensively evaluated by FE-SEM, CLSM, He-measured porosity and permeability, N2 adsorption, and rock pyrolysis experiments. The results show that the hydrocarbon generation potential is poor, reaching mature to high mature stage, and oil and gas coexist in the Da’anzhai Member. The intercalated limestone is dense. The inter-calite pore connectivity is poor. The foliation fracture, interlayer fracture, and calcite cleavage constitute the main occurrence space of shale oil. The oil content of foliated clay shale is good, and fracture development is the premise of shale oil mobility and high yield. Vertically, the fractures of the interbedded combination of shale and limestone are relatively developed, making it the preferred sweet spot for shale oil. Layered structures are conducive to the formation of bedding planes. Layered shale has exploration potential in areas with high levels of thermal evolution. Based on the organic matter abundance, oil property, and lithofacies combinations, it is proposed that the northern Yilong and southern Dazhou are favorable exploration areas for interlayer type shale oil. While the areas between Yilong and Dazhou are favorable exploration areas for pure shale type shale oil.

Due to the presence of obstacles in the observation site or the unique characteristics of the target object, it is not always possible to lay out survey lines for electrical resistivity tomography in a straight manner. In some cases, even the electrode array cannot be placed directly above the target body. As a result, there are limitations on the application of resistivity tomography method under certain site conditions. This paper focuses on studying 3D electrical resistivity tomography technology for restricted observation sites. The study begins by designing three electrode array observation systems specifically tailored for restricted observation sites: “□” shaped observation system, “U” shaped observation system, and “L” shaped observation system. Subsequently, we investigate the 3D inversion imaging method for determining resistivity using any type of observation system. Finally, we analyze the detection effectiveness of different observation systems through model testing and apply “□” shaped observation system to detect the base structure of an ancient tower in Zhejiang Province. Based on both geoelectric model detection results and the actual site conditions, all three special observation systems for 3D electrical resistivity tomography can effectively capture 3D electrical characteristics below the restricted observation site, thereby providing valuable references for analyzing anomalies within the target area. Among them, the “□” shaped observation system demonstrates the best imaging performance, followed by the “U” shaped observation system, while the “L” shaped observation system shows relatively weak performance. In practical applications, it is essential to consider site conditions and exploration objectives when selecting the electrode array geometry and the number of electrodes, in order to optimize the imaging results.

 Greenhouse gas emissions have caused severe global climate change, and countries around the world are taking measures to mitigate the greenhouse effect caused by carbon emissions. Carbon dioxide capture and storage (CCS) is emerging as a large-scale greenhouse gas reduction technology and is gradually becoming one of the most important means of mitigating the greenhouse effect. There are a series of issues in the implementation of this technology, among which the geomechanical problems caused by injection and storage cannot be ignored. This paper reviews the impacts and risks caused by geomechanical problems due to injection and storage in CCS. The results indicate that CO2 injection triggers pore pressure variations, thermal stress, and coupling effect of chemistry and mechanics, leading to reduced reservoir rock strength, intensified deformation, and subsequent surface deformation. InSAR technology effectively monitors surface deformation, while site-specific microseismic monitoring reveals a direct correlation between injection rates and seismic activity. Controlling injection rates and pressures can significantly reduce the probability of caprock fracturing and fault reactivation. Furthermore, numerical simulation serves as a primary tool for assessing geomechanical risks at storage sites. Simulations demonstrate that selecting caprock with low-permeability and low-reactivity lithology minimizes leakage risks, and comprehensive evaluation of fault stress states is essential to avoid high-activity fault zones.

It is scientifically significant to establish soil remediation standards for the synergistic management of soil and groundwater. Previous studies often assumed that contaminant sources directly affect the saturated zone, with little consideration for the lag, attenuation, and variations in pollutant sources during migration in the vadose zone. Addressing this issue, in this paper coupling the one-dimensional vertical transport analytical solution of pollutants in soil with the three-dimensional transport analytical solution of pollutants in groundwater, the influence of factors affecting pollutant migration and transformation on the synergistic remediation threshold of soil and groundwater is investigated. The results indicate that without considering the synergistic remediation of soil and groundwater, based on the screening values of soil for the first category of land use in current standards, benzene and chlorobenzene should be remediated to 1 mg/kg and 68 mg/kg respectively. Considering the synergistic remediation of soil and groundwater and aiming for compliance with downstream groundwater quality standards, the calculated synergistic remediation thresholds for soil and groundwater are 0.150 mg/kg and 150.000 mg/kg respectively. Failure to consider the synergistic remediation of soil and groundwater may result in inadequate or excessive soil remediation at the site.

 In recent years, large and medium-size uranium deposits such as Qianjiadian, Baolongshan and many uranium minings have been discovered through uranium exploration in the southern Songliao basin. Diabase is widely developed in the uranium ore concentration area, mainly distributed around the uranium deposit, near the oxidation fronts of Yaojia Formation, exhibits a spatial correlation with uranium mineralization. While the relationship between diabase and uranium mineralization remains debated, core observation, microscopic identification, and fluid inclusion analysis suggest a significant hydrothermal influence of diabase on uranium mineralization. The microscopic identification shows brannerite formed at a higher temperature and metasomatized the early ilmenite, filling along the fissures, and co-existing with automorphic pyrite, revealing that the formation of uranium deposits in southern Songliao basin may be superimposed on the factors of late magmatic hydrothermal activity. Fluid inclusion studies yield an average temperature of 115.7 ℃, characterizing the ore fluid as low-temperature hydrothermal, exceeding the temperature of uranium-containing oxygen-containing fluids (24.5  ℃) in Yaojia Formation oxidation zone. The inclusion salinity distribution shows low, medium, and high salinity areas (three intervels), representing three distinct fluid activity periods. Combining the existing chronology, geochemistry and exploration results, the uranium mineralization in the southern Songliao basin is divided into four stages: primary preconcentration (96.0-87.0 Ma), uranium-containing and oxygenated water infiltration mineralization (67.0-53.0 Ma), hydrothermal superimposition and reworking (43.0-37.0 Ma), and interlayer oxidation continuous superimposition (17.0-0.7 Ma). Notably, the  hydrothermal superimposition period (43.0-37.0 Ma) coincides with the major intrusion age (49.4-39.1 Ma) of diabase.

To investigate deformation mechanisms and surface settlement patterns of subway deep foundation pit retaining structures under composite geology, this study focuses on a metro station excavation in Changchun through integrated field monitoring and numerical modeling. The foundation pit is located in the terrace geomorphic unit of the alluvial valley. The excavation process of the foundation pit (bored pile with steel support, bored pile with anchor cable) was simulated by MIDAS GTS NX, a finite element simulation software. By comparing the field monitoring data with the numerical simulation results. The variation rules of horizontal displacement and surface settlement of two supporting forms of piles in composite stratum were analyzed.The results show that the horizontal displacement curve of the pile support section shows a “bow” shape with the increase of the depth of foundation pit, which is small at both ends and large in the middle. In the pile-anchor support section, the horizontal displacement of pile body shows a trend of approximate “funnel” shape with the change of foundation pit depth.As the distance from the monitoring point to the edge of the foundation pit increases, the surface settlement value presents a trend of increasing first and then decreasing, and the maximum value appears in the position within 3-5 m from the edge of the foundation pit. Reasonable setting of steel support axial force and anchor cable tension is beneficial to effectively control foundation pit deformation and surface settlement. The numerical simulation results are basically consistent with the change law reflected by the actual monitoring data, which verifies the rationality and reliability of the model. 

This paper aims to conduct the first analysis and evaluation of the oil and gas geological conditions and exploration potential of the Lower Carboniferous strata in the Santanghu basin, which has the lowest level of exploration and the most uncertain resource prospects. Based on field outcrop observations, geochemical analysis, and reservoir thin section observations, the vertical sedimentary environment evolution, hydrocarbon source rocks, and reservoir geological characteristics of the target layer are revealed. The study indicates that the Santanghu basin in the Early Carboniferous was a residual back-arc basin with shallow marine sedimentary characteristics. The vertical sedimentary environment of the Lower Carboniferous strata experienced four stages of evolution: Island arc volcanic activity, closure of ancient oceans leading to semi-deep water environments, compression and uplift of continental-derived clastic sediment filling shallow water environments, and orogenic uplift basin contraction. Among them, hydrocarbon source rocks are widely distributed in the semi-deep water environment and shallow water sedimentary environment, and the organic matter type meets the standard of moderate hydrocarbon source rocks. The presence of abundant asphalt in rock thin sections also confirms that the hydrocarbon source rocks of the Lower Carboniferous not only have hydrocarbon generation ability but also have undergone a large amount of hydrocarbon expulsion processes. The Lower Carboniferous strata developed two major types of reservoirs: Igneous rocks and clastic rocks. Although the reservoirs are generally tight, the development of fractures and dissolution pores has improved the conditions for oil and gas accumulation, especially the development of granite fractures, which has a significant connectivity effect on dissolution pores. Comprehensive analysis suggests that around the hydrocarbon source rocks of the Lower Carboniferous, two types of oil and gas reservoirs can be developed: Self-generated and self-stored, and lower-generated and upper-stored. Among them, self-generated and self-stored oil and gas reservoirs are developed in structurally stable areas far from the oil source faults and have the characteristics of primary reserves. Lower-generated and upper-stored oil and gas reservoirs are developed near oil source faults within the Carboniferous system and are related to fault lithology oil and gas reservoirs.

 In order to clarify the oil and gas exploration prospects in the middle and deep layers of Nanbaxian area in the northern margin of Qaidam basin and predict the distribution area of favorable reservoirs, this paper takes the Upper Member of Xiaganchaigou Formation in the Late Oligocene of Paleogene as the research object. Based on the comprehensive analysis of detailed core observation and drilling (logging) data, combined with the comprehensive analysis results of casting thin sections, clay mineral assemblages, chloride ion content of mudstone cuttings, porosity and permeability variation characteristics, the sedimentary environment of the Upper Member of Xiaganchaigou Formation in this area during the sedimentary period, the characteristics of clastic reservoir physical properties and their controlling factors were studied deeply. The results show that: (1) The sedimentary period of the Upper Member of the Xiaganchaigou Formation in the Nanbaxian area is the sedimentary environment of the braided river delta front. The lake water is mainly fresh-brackish, and the reservoir is mainly lithic feldspar sandstone and feldspar lithic sandstone. The compositional maturity of sandstone varies greatly and the structural maturity is low. The climate is dry and warm, and the clay mineral assemblage is dominated by illite and illite-montmorillonite mixed layer. The content of kaolinite and chlorite is low, and montmorillonite is absent. (2) The favorable reservoir of the Upper Member of Xiaganchaigou Formation in Nanbaxian area is the underwater distributary channel sand body and the mouth bar sand body of the braided river delta front in the Ⅳ-1-Ⅳ-4 sand group, with an average porosity of 16.3% and an average permeability of 37.4 × 10-3μm2. It is a medium porosity and low permeability reservoir and a medium porosity and medium permeability reservoir. The primary intergranular pore is the main pore type. Among them, the physical properties of the sand body of theⅣ-1-Ⅳ-4 sand group are better than those of the Ⅳ-5 sand group, and the physical properties of the underwater distributary channel sand body are better than those of the mouth bar sand body. (3) The controlling factors of reservoir physical properties in the Upper Member of Xiaganchaigou Formation in Nanbaxian area are mainly sedimentary facies and cementation, followed by compaction and dissolution. The high content of secondary calcite cement is the main reason for the poor reservoir physical properties of Ⅳ-5 sand group.

 The propagation matrix theory considers the effects of transmission loss and inter-layer multiple waves on seismic responses. It provides the reflection coefficient spectrum for longitudinal and transverse waves in multi-layer media at arbitrary incident angles. This theory can yield higher accuracy in amplitude-versus-angle (AVA) multi-parameter inversion results than the Zoeppritz equations and their simplified versions. The inversion of the time-domain propagation matrix method requires a significant amount of memory because it involves computing the full-frequency Jacobian matrix. In contrast, frequency-domain inversion only focuses on specific frequencies, resulting in lower memory usage. The propagation matrix method effectively meets the requirements for frequency-domain inversion by solving the reflection coefficient spectrum in the frequency domain. This paper computes the gradient of the objective function in the frequency domain, and employs the L-BFGS (limited-memory Broyden-Fletcher-Goldfarb-Shanno) algorithm to accelerate inversion convergence. To validate the effectiveness of the frequency-domain propagation matrix method, we conduct inversions on both simulated and real data. The application of the propagation matrix seismic prestack inversion method in the frequency domain can stabilize the inversion of layer parameters. Compared to the results from the Zoeppritz equations, the frequency-domain propagation matrix inversion shows higher accuracy.

 Grain size analysis is a very important method in the field of sedimentation. It is widely used in the evaluation of oil and gas reservoirs and the identification of sedimentary environment for terrigenous clastic rocks, but is rarely applied to endogenous clastic rocks such as phosphorus rocks. In this paper, the sedimentary phosphorite of Yangchang phosphate mine in Zhenxiong County, Yunnan province, is taken as the research object. The grain size information is obtained by measuring thin sections under the microscope, and the grain size distribution histogram, frequency curve, cumulative frequency curve, and probability cumulative curve are drawn and analyzed. The sedimentary environment of the study area is analyzed by using Cent-Median diagrams and structural parameter scatter diagrams. The research results indicate that grain size parameters are closely related to the hydrodynamic conditions of sedimentary water bodies. High energy hydrodynamic environments are prone to the formation of phosphate rocks with larger average grain size, poor sorting, bimodal and flat kurtosis. Low energy stable environments often form phosphate rocks with smaller average grain size, good sorting, single peak and sharp kurtosis. Based on various parameters and diagrams as well as the structural and texture characteristics, the grain size parameters of the sample exhibit the characteristics of beach sand. It is concluded that the Zhenxiong Yangchang phosphate mine was deposited in a shallow marine environment with continuous sea level oscillations and strong hydrodynamic forces.

 At present, deep learning-based fault recognition methods are emerging in an endless stream, focusing on the U-shaped network. However, the U-shaped network uses a large number of conventional convolutions, ignoring the problems of feature redundancy and over-fitting while improving the effect of feature extraction, resulting in high network complexity. In order to ensure the recognition effect and reduce the problem of feature redundancy, this paper proposes a lightweight fusion semantic segmentation network (LF-SeNet) for three-dimensional fault recognition. Compared with the traditional fault recognition network, LF-SeNet combines the idea of skip connection and feature fusion. The feature fusion module includes three-dimensional separable convolution, simple attention mechanism (SimAM), Dropout layer and finite matrix product operation, forming a lightweight feature fusion module. The effect of feature extraction is effectively guaranteed. In order to effectively reduce the complexity of the network, this paper combines the dilated convolution and the lightweight feature fusion module. On the one hand, it reduces the computational complexity of the network, and on the other hand, it reduces the feature redundancy problem caused by conventional convolution. In addition, this paper uses the Dropout layer and data enhancement method to improve the generalization ability of the network and alleviate the problem of overfitting. The method is tested on the FaultSeg3D dataset. The results show that the parameter amount of LF-SeNet is 2.56M, the number of floating-point operations is reduced by 95.59G, and the intersection-over-union ratio is increased by 2% compared with the traditional U-shaped network. Finally, this paper uses three-dimensional data synthesis technology to visualize the fault identification map. The experimental results show that the faults identified by LF-SeNet are continuous and clear, indicating that the network has better generalization ability, which proves the effectiveness of LF-SeNet in fault identification. 

 The exploration potential of the Panyu low uplift in the Pearl River Mouth basin (PRMB) is considerable. However, the level of research remains low and is limited to individual depressions, lacking systematic analysis of the impact of fault structures on the sedimentation of depressions and the source-sink system. This limitation hinders subsequent exploration and development activities. Therefore, this paper systematically analyzes the relationship and evolutionary sequence of the source-sink response under the control of tectonic activity in the Panyu low uplift area of the PRMB, based on the latest 3D seismic data and drilling information. The Cenozoic fault activity in the Panyu low uplift area exhibits significant zonation and periodicity under the influence of two existing fault systems, NE-NEE and NW-NWW, during the Late Mesozoic. In the Early Wenchang period, the faulting controlled the depression, with NE-NEE direction dominating in the western region and EW direction in the eastern region, while the fault activity increased during the Wenchang period compared to the Enping period. Three types of fault-controlled depressions developed within the area: Migration-type, combination-type, and inheritance-type. The source-sink system in the area utilizes the felsic granite from the uplift area and the ancient Pearl River as the material source with steep slope faults, gentle slope transition trenches, and reverse fault steps acting as transportation pathways, while half-graben depressions serve as the sedimentation zones. In the Early Wenchang period, a source-sink system dominated by nearby material sources and large source areas developed in small lake basins; In the Late Wenchang period, a coexistence of nearby and distant material sources in the small source area of large lake basins occurred; And during the Enping period, a large lake basin system developed with distant sources in the western region and nearby sources in the eastern region. Overall, the highest quality semi-deep lake facies hydrocarbon source rocks developed in the Late Wenchang period characterized by high tectonic activity rates and low material source supply; Large-scale distant deltaic sedimentary sand bodies widely developed in the Enping Formation period marked by low tectonic activity rates and high material source supply, the source rocks and the sand bodies formed the most favorable vertically combination of source, reservoir and cap rocks.

At present, most constitutive models are difficult to simultaneously reflect the creep behavior of soft and hard rocks, and their applicability is limited. To construct a more widely applicable rock creep model, based on the generalized Kelvin-Voigt model, the theory of fractional calculus operators and damage mechanics theory were introduced to construct a new rock fractional creep model considering time-dependent damage, which is extended to three-dimensional stress space. Model validation analysis is found that: 1) Simulating uniaxial compression creep tests on marble and triaxial compression creep tests on sandstone using newly constructed one-dimensional and three-dimensional models, the average R² (goodness of fit) was of 0.994 4 and 0.994 2 respectively, proving the feasibility of the newly constructed models; 2) At the same time, the newly established model and the fractional-order creep model in related literature were used to simulate the triaxial creep data of sandstone, and the average R² was 0.994 2 and 0.992 7, respectively, and the average R2 of the newly established model was 0.001 5 higher than that of the previous model; 3) The simulation of triaxial compression creep test data for four types of rock hardness, namely granite, slate, mudstone, and fully weathered granite, showed an average R² of 0.989 9, demonstrating the applicability of the new model.

The Wulanhada-Chuludaban area in Inner Mongolia is located in the middle section of the Zhalantun volcanic rock-type uranium mineralization prospecting zone and is one of the hydrothermal uranium polymetallic mineralization clusters in Northern China. The area experienced intense and frequent Mesozoic volcanic eruptions, providing excellent geological conditions for mineralization and promising exploration prospects. Through the collation of previous data, comprehensive mapping, and uranium geological survey and evaluation, the geological characteristics and ore-controlling factors of volcanic rock-type uranium deposits in the Wulanhada-Chuludaban area have been preliminarily summarized. Through drilling verification, it is found that the volcanic rock-type uranium deposits in the research area can be classified into two types based on the main ore-controlling factors: subvolcanic rocks and altered fracture zones. It is believed that the peak period of uranium mineralization in the research area was from the Late Jurassic to the Early Cretaceous, mainly concentrated between 149 and 99 Ma, with the characteristics of a large time span and multiple stages. Uranium mineralization anomalies are mainly distributed along the NE-trending F_W2 trans-shell faults and are mostly found in the NE and NW-trending secondary faults and structural fracture zones. Uranium mineralization is mainly controlled by uranium source, strata and structure, subvolcanic rocks, and hydrothermal alteration. Hematitization, fluoritization, and silicification can be used as direct exploration indicators. The next exploration work should focus on searching for altered fracture zone-type uranium mineralization on both sides of the NE-trending F_W2 ore-controlling faults, and secondly, strengthen the exploration of uranium mineralization around volcanic structures and subvolcanic rocks.

The method of seismic data reconstruction is an important way to improve sampling density and obtain complete wavefield information in seismic signal processing. The data collected from field exploration is often incomplete or irregularly sampled due to limitations in surface conditions and cost control. Therefore, studying methods for reconstructing irregular seismic signals is of great significance. Based on the assumption that irregular seismic data can be regarded as random sparsity of regular complete data, the mathematical statistical distribution of the two data is highly consistent in the data interval and the performance in the sparse domain is extremely similar, this paper proposes a method of data reconstruction by using residual convolutional encoder-decoder to reduce the dimensionality of the data to the sparse domain and then increase it. Furthermore, this paper proposes amplitude consistency correction processing on the input data of the network to balance energy, in order to address the serious impact of inconsistency in amplitude depth and shallow layers caused by seismic attenuation, as well as significant differences in mathematical statistical distribution between different data, on the training and generalization of neural networks. The synthetic data example proves that the proposed method has higher accuracy than traditional two-dimensional prediction error filter and residual network interpolation methods, and is more efficient than traditional three-dimensional prediction error filter interpolation method. Different field land and ocean data examples have achieved good reconstruction results, proving that this method greatly increases the generalization ability of the network and reduces the training difficulty of the network.

 The helium gas (He) is one of the important strategic scarce resources, and the understanding of depletion mechanisms and resource potential is extremely weak. The Xinchang gas field from the Sichuan basin is taken as an example in this study to analyze the abundance and origin of helium, and the depletion mechanisms and main controlling factors are revealed with the resource potential being further discussed. The study indicates that natural gas from different strata of the Xinchang gas field displays the He content ranging from 0.007 7% to 0.040 0%with a low He content. The R/Ra ratio ranges from 0.010 to 0.050, suggesting a typically crustal source with little contribution by mantle-derived He. The He content displays positive and negative correlations with the N2 content in natural gas and the content of total dissolved solids (TDS) in reservoir water, respectively. The depletion of helium is mainly attributed to the source of helium being the strata themselves rather than the basement rocks due to the underdevelopment of deep faults, the high gas generation intensity of source rocks and charging intensity of natural gas, as well as the small uplift amplitude and weak dissolution effect since the Cretaceous. The Xinchang gas field is a medium helium gas field with a proven helium reserve of 25.45×106 m3. The exploration of high-helium and helium-rich gas resources in the Sichuan basin is suggested to pay attention to the areas with the development of basement faults, medium gas generation intensity of source rocks, and high uplift amplitude after gas accumulation.

The widespread Mesozoic granitoids in the Great Xing’an Range play a pivotal role in deciphering the tectonic-magmatic evolution of Northeast China. To constrain the emplacement age, petrogenesis, and tectonic setting of granites in the northern segment of the Great Xing’an Range, this study conducts integrated petrographic, LA-ICP-MS zircon U-Pb geochronological, zircon Hf isotopic, and whole-rock geochemical investigations on the Kuzhong granitic pluton. Zircon U-Pb geochronology yields a crystallization age of (136.5±1.7) Ma, placing the magmatic event in the Early Cretaceous. Whole-rock geochemical data reveal that the pluton represents a highly fractionated calc-alkaline I-type granite, characterized by high silica (w(SiO₂)=70.40%-73.54%), elevated alkalis (w(Na₂O+K₂O)=8.77%-9.30%), enrichment in large-ion lithophile elements (e.g., Rb, Ba), and depletion in high-field-strength elements (e.g., Nb, Ti, P). Chondrite-normalized rare earth element patterns exhibit right-dipping trends with pronounced negative Eu anomalies. The homogeneous zircon Hf isotopic compositions (εHf(t)=5.1-8.8, mean 6.7) suggest magma derivation predominantly from partial melting of juvenile lower crust. Synthesizing regional tectonic evidence, we propose that the Kuzhong granite formed in a post-orogenic extensional setting following the closure of the Mongol-Okhotsk Ocean, overprinted by lithospheric thinning and asthenospheric upwelling driven by Paleo-Pacific plate rollback. This thermotectonic process facilitated melting of juvenile lower crustal materials, ultimately generating highly fractionated calc-alkaline I-type granites.

In the domains of oil and gas exploration and geoengineering, precise lithology identification holds paramount importance for the assessment and utilization of resources. The inherent complexity of geologic data and the imbalanced distribution of lithology samples pose significant challenges to traditional methods in terms of lithology identification. In this paper, we propose a methodology for lithology identification that combines SMOTE (synthetic minority over-sampling technique) with extra trees. Firstly, the SMOTE method is employed to enhance the representation of minority class samples, thereby improving the balance of the training data. Secondly, the lithology classification model is constructed using the high efficiency and strong generalization ability of extra trees. The experimental findings demonstrate that the recognition accuracy of extra trees is 85.54%, which is 5.58%, 2.55%, 2.35%, and 2.08% higher than that of other machine learning methods—gradient boosting decision tree (GBDT), extreme gXGBoost), light gradient boosting machine (LightGBM), and random forest method, respectively. The prediction bias of the model caused by sample imbalance is mitigated by SMOTE sampling, resulting in enhanced recognition accuracy for specific lithology categories within each model. Consequently, this leads to an overall enhancement in the performance of the model. The extra trees model exhibits the best performance, achieving an identification accuracy of 86.62%, which represents improvements of 4.71%, 2.56%, 1.55%, and 2.02% over GBDT, XGBoost, LightGBM, and random forest, respectively. These results confirm the effectiveness of combining SMOTE with extra trees for lithology identification.

The western Jilin is located in a transitional zone between agriculture and animal husbandry, characterized by arid climate, fragile ecology, and relatively lagging economic development. Investigating the relationship between land use transitions and ecological quality is crucial for sustainable utilization of land resources. This paper analyzes the characteristics of land use transitions and changes in habitat quality from 1990 to 2020 in western Jilin using ArcGIS and the InVEST model. By quantifying the contribution rate of habitat quality, it examines the impact of land transitions on habitat quality in this region. The results show that  land conversions were concentrated in cultivated land, grassland, and unused land. Specifically, cultivated land significantly increased to 54.72% of the total area by 2020, while grassland decreased annually, becoming the primary source for cultivated land expansion. Habitat quality in western Jilin experienced a process of initial improvement followed by decline, with habitat quality indices of 0.411, 0.423, 0.386, and 0.370 respectively, indicating overall low levels. The conversions between ecological lands, cultivated land, and unused land were the main drivers of habitat quality changes. Furthermore, the local spatial distribution of habitat quality in western Jilin shows a relatively clustered pattern with separately aggregated high and low-quality habitat areas, characterized by “large concentration, small dispersion.” This research provides insights into the complex dynamics of land use and ecological quality in ecologically fragile regions, offering valuable information for sustainable land management practices.

 A typical low resistivity reservoir is developed in the NgⅢ Formation (3rd Member of Neogene Guantao Formation) of C oilfield， Bohai Bay basin. Analyzing the influential factors of reservoir resistivity is of great significance to the efficient development. In this research， X-ray diffraction (XRD)， scanning electron microscopy （SEM）， blue-dye thin sections， and cation exchange capacity test (CEC) were used to quantitatively characterize the micro-features, including the clay mineral content and morphology， rock framework grain contact， and reservoir conductivity. The results showed that the content of smectite in clay minerals of the normal resistance reservoir is 23%-44%， while that of the low resistance reservoir is 39%-64%. According to the CEC experiments of reservoirs in different regions， the content of illite-smectite mixed layers is positively related to the cation exchange capacity. The smectite in the study area mainly exists in the form of illite-smectite mixed layers, and the illite-smectite mixed layers are distributed in two types. The first type is thin film， which wraps rock framework grains， leading to the formation of a conductive film on the surface of rock framework grains， this type accounts for about 80%; The second type exists between rock grains in flocculent and dispersed form， and accounts for about 20%， this type is relatively dispersed and fails to form a continuous conductive structure. Moreover， the low resistivity reservoir in the study area is mainly in Guantao Formation， according to the observation of blue-dye thin section, the rock framework grains are in point contact to line contact due to compaction, which leads to the contact of illite-smectite mixed layers conductive film on the surface of rock framework grains and the formation of continuous conductive structure. When illite-smectite mixed layers are in film shape and rock framework grains are in contact with each other, illite-smectite mixed layers can easily form a continuous conductive structure.

In the vicinity of Wujianfang Village, Lianggang Town within the Trans-North China orogen (TNCO) of the North China craton (NCC), we have discovered a set of garnet amphibolitesduring the 1/50 000 regional geologic survey. The garnet amphibolites were exposed as lenses in the paragneisses of Yuanfang Formation of the Fuping Group, showing typical “white-eye socket” structure, indicating that they were probablyretrograded eclogites or high-pressure mafic granulites. In order to gain a deeper understanding of the metamorphic genesis and geological significance of this suite of garnet amphibolites, detailed studies were conducted on their petrology, mineral chemistry, geochemistry, metamorphic evolution, and zircon U-Pb geochronology. The results suggest that they underwent three stages of metamorphic evolution: An early prograde metamorphic stage (M₁), a peak high-pressure granulite facies stage (M₂), and a retrograde stage (M₃). The early prograde stage features mineral assemblages of Am+Pl+Q inclusions within garnet, with metamorphic p-T conditions of approximately 756.0 ℃/ 6.0×10⁸ Pa; The peak high-pressure granulite facies stage shows a mineral assemblage of Grt+Cpx+Pl+Q+Melt, with p-T conditions of 884.1-987.5 ℃ / (12.2-14.2) ×10⁸ Pa; The retrograde stage is characterized by a “white-eye” structure around garnet and partial replacement of clinopyroxene by late amphibolewith residual ilmenite, forming a mineral assemblage of Am+Pl+Q+Ilm ± Grt and showing p-T conditions of 706.6-776.7 ℃/(3.7-4.2)×10⁸ Pa; The metamorphic evolution of these garnetamphibolites generally exhibits aclockwise p-T includinga near-isothermal decompression (ITD) process. LA-ICP-MS zircon U-Pb dating indicates a retrograde metamorphic age range of 1.86-1.84 Ga. The geochemical characteristics reveal that their protoliths were tholeiitic basalt formed under an island arc environment of convergent plate margin. Combined with previous studies, the garnetamphibolites exposed in the Lianggang region are retrograde products of high-pressure granulites,which are similar to the formation process of the Hengshan-Huai’an-Xuanhua-Chengde high-pressure granulite belt of the TNCO. This suggests they may also be a result of the collision between the eastern and western block that occurred at about 1.85 Ga. This understanding extends the high-pressure granulite and retrograde eclogite belt in the north-central part of the TNCO southeastward to the Yixian-Laiyuan area in Hebei Province.

To investigate the heavy metal pollution status and ecological and exposure risks in agricultural soils of the water town area in Dongguan City, vegetable bases and agricultural land of large traffic arteries both sides within the water town area were selected as study sites. A total of 32 soil and vegetable samples each were collected from vegetable bases and agricultural land of large traffic arteries both sides for analysis. Firstly, the pollution characteristics of eight heavy metals, including Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni, were evaluated using the single-factor pollution index (IP) and the Nemerow comprehensive pollution index (PN). And then, ecological risk assessment and agricultural product quality and safety assessment were conducted, and the causes of heavy metal pollution were finally investigated. The results showed that the mean values of the mass fractions of the remaining seven heavy metals in vegetable bases soils were lower than the city’s soil background values, except for Ni; The mean values of the mass fractions of the remaining six heavy metals in agricultural land of large traffic arteries both sides were lower than the  mean values in the water town area, except for Pb and Ni; And the mean values of the mass fractions of the remaining heavy metals, except for Pb, Zn, and Ni, were lower than the city’s soil background values. Based on the single-factor pollution index, heavy metal accumulation is observed in the soil of vegetable bases and agricultural land of large traffic arteries both sides. Within the vegetable bases, 6.67% of the sampling sites exhibit Cd mass fraction surpassing the risk screening values for agricultural soil. In agricultural land of large traffic arteries both sides, 17.64%, 23.53%, and 5.88% of the sampling sites display Cd, Pb, and Cu mass fraction exceeding the risk screening values for agricultural soil, all remaining below the regulatory thresholds for pollution risk. Evaluation of the Nemerow comprehensive pollution index showed that agricultural land of large traffic arteries both sides were slightly polluted to varying degrees, with 40.00% and 64.70% in the mildly polluted category, respectively. The ecological risk evaluation showed that the potential ecological hazard index (Ie) of Hg reached the medium ecological risk level in 6.67% of the study sites in the vegetable bases, and the ecological risk hazard index (Ir) was at the medium ecological risk level in 6.67% of the study sites. For agricultural land of large traffic arteries both sides, 11.76% of the study sites had Cd Ie at medium ecological risk level, 17.64% of the study sites had Hg Ie at medium ecological risk level, and 5.58% of the study sites had Ir at medium ecological risk level. The evaluation of the quality and safety of agricultural products showed that there were Cd exceedances in the soil of vegetable bases and in agricultural products in agricultural land of large traffic arteries both sides. The reason for the excess of heavy metals in vegetable bases is related to the application of chemical fertilizers and pesticides and agricultural land of large traffic arteries both sides have heavy metal pollution from transportation sources and pollution inputs from agricultural sources.

The tuff lava of the Yingcheng Formation in the Yingshan fault depression of the Songliao basin is characterized by ultra-low porosity and low permeability. In order to characterize the nanometer to micron multiscale reservoir space and evaluate qualitatively and quantitatively, the factors influencing tuff lava reservoir development in the Yingcheng Formation are discussed. Based on core observation and thin section identification, combined with FE-SEM, LTNA, HPMI, CPMI, and NMR, the micropore characteristics of the Yingcheng Formation tuff lava were characterized qualitatively and quantitatively at multiple scales. The results show that: The tuff lava of the Yingcheng Formation is mainly composed of vitric debris and rhyolitic debris. The reservoir space types are mainly devitrification pore, feldspar dissolved pore, and illite intercrystalline pore. A great number of secondary pores and fissures are formed during the devitrification process, and provide about 66.8% of pore volume, which is vital to improving the reservoir physical properties. 

The Yishu fault zone is located in the middle section of the Tanlu fault zone, consisting of multiple nearly north-northeast trending faults. Significant variations in crustal structure are present on both sides of the fault zone. The seismic velocity and velocity variations are important parameters for understanding the deep structural characteristics of the earth and the potential damage of the medium. Based on the continuous seismic waveforms from permanent stations in the Yishu fault zone and surrounding regions from January 2011 to December 2014, we perform ambient noise tomography to monitor the phase velocity variations of Rayleigh wave. The results show that the velocity variations correlate well with the small earthquake activities. The earthquakes (M>2) are mainly concentrated near the velocity reduction and velocity transition zones. The velocity variations near the Yishu fault zone are not significant, indicating that the fault activity is relatively weak recently. The velocity variations in the Jiaobei uplift are notable between 2013 and 2014, which is related to surface deformation. It is speculated that the compression effect of regional stress is the main factor for the velocity increase in the Jiaobei uplift.

The Jinchang copper-gold deposit in Dongning Country, Heilongjiang Province, is a superlarge deposit in eastern Jilin-Heilongjiang, mainly developing three types of ore bodies: Cryptoexplosive breccia type, veinlet disseminated type, and fracture-filling type. Among them, the breccia type and veinlet disseminated type orebodies together consitutec a hydrothermal Cu-Au mineralization system with a shallow epithermal high-sulfidation type and a deep porphyry type. This paper focuses on the J-0 breccia type Cu-Au ore body, the J-1 breccia type Au ore body, and No.18 veinlet disseminated ore body. Through microthermometrry of fluid inclusions, laser Raman microprobe, rare gas isotope analysis, hydrogen-oxyen isotope analysis, with latest geochronological results, the properties, origin, and evolution of these ore-forming fluids in this copper-gold hydrothermal deposit are systematically studied. The underlying mantle-derived magma forms high-salinity, highly oxidizing Cu-rich metallogenic fluids through primary boiling. During the ascent process, these fluids undergo secondary boiling and react with the surrounding rocks, forming the J-0 breccia type copper-gold ore body in the shallow cryptovolcanic zone and the No. 18 disseminated veinlet type copper-gold ore body in the deep fracture filling zone. The addition of late atmospheric precipitation further promotes the precipitation of residual metallogenic elements. The magma chamber in the shallow crust directly exsolves high-salinity ore-bearing fluids. During the ascent of this fluid to the shallow crust and reaction with the surrounding rocks, the decrease in temperature and pressure leads to the precipitation of a large amount of gold and other metallogenic elements in the breccia and cement, forming the J-1 breccia type gold ore body.

The Jiufotang Formation has huge hydrocarbon resources in the Ludong depression of Kailu basin, but there is less research on the relationship between Milankovitch cycle and sedimentation patterns, especially fine-grained sedimentation, which restricts the prediction of source rock distribution. In this study, wavelet and spectrum analyses of natural gamma log data were used to divide the Milankovitch cycle of the Upper Member of the Jiufotang Formation, and the sedimentary environment at that time was compared with the divided cycle to clarify the stratigraphic sedimentary response characteristics. The results show that 13 Class Ⅳ cycles, 25 Class Ⅴ cycles and 66 Class Ⅵ cycles can be identified in the Upper Member of  Jiufotang Formation. According to the lithology and long eccentricity characteristics of the sedimentary rocks in the Upper Member of  Jiufotang Formation, it can be divided into two stages of sedimentary environment evolution: Warm and humid climate half-cycle and cold and dry climate half-cycle. In the warm and humid climate half-cycle, the increasing depth of waterbody benefits the deposition of fine-grained sedimentary rocks. The warm and humid climate period is the period of hydrocarbon source rock development, and the cold and dry climate period is the period of reservoir development. Combining with relevant geochemical data, the development sites of reservoirs and hydrocarbon source rocks can be predicted.

The intelligent identification of shale scanning electron microscope (SEM) images can rapidly analyze shale reservoir minerals, which is one of the important means of predicting the “sweet spot” of shale oil reservoirs, and is also a future technological development trend. Traditional methods have problems such as low automation, low sample suitability, and limited feature extraction when identifying mineral components. To this end, this paper proposes a BlendMask-based SEM image characterization method for shale. Firstly, image preprocessing techniques such as bilateral filtering, Laplacian, and image normalization are used to denoise, sharpen, and unify the pixel of original images to improve the quality of training samples; Then, image augmentation methods such as rotation, scaling, and luminosity change are used to construct augmentation strategies to expand the number of datasets; And finally, the BlendMask network is improved by using the attention mechanism and the depth separable convolution which is used to realize the component segmentation and recognition of images. The experimental results of shale SEM images applied to Haita basin show that the segmentation accuracy and recall of the improved method are improved by 0.02-0.20 and 0-0.59, respectively, and the segmentation time is reduced by 1.29-2.70 s compared to the BlendMask model.

 The Yanbian region of eastern Jilin Province, located on the southeastern margin of the Xingmeng orogenic belt and western Paleo-Pacific tectonic domain, provides a critical area for understanding their superposition and transformation. Dark microgranular enclaves within granitic rocks serve as valuable probes into deep Earth dynamics, recording crucial information on magma source characteristics and evolution. This study investigates Early Jurassic Yueshandong and Mingnandong granitic plutons in the Yanbian area, focusing on the genesis of the granitic rocks and their enclaves by petrogeochemical and zircon Lu-Hf isotope analyses to ascertain the tectonic background of Early Jurassic magmatism. The w(SiO2) of the dark enclaves in the Yueshandong pluton and the Mingnandong pluton are 51.09% to 53.52% and 49.53% to 51.96% respectively; The w(Cr) are 1 192.00×10-6 to 3 219.00×10-6 and 72.68×10-6 to 194.90×10-6 respectively; The w(Ni) are 330.60×10-6 to 693.20×10-6 and 58.61×10-6 to 81.06×10-6 respectively; The w(V) are 595.10×10-6 to 800.70×10-6 and 599.80×10-6 to 619.60×10-6 respectively; The w(SiO2) of the host rocks in the Mingnandong pluton is 65.75% to 68.19%, the w(Cr) is 33.20×10-6 to 57.54×10-6, the w(Ni) is 19.25×10-6 to 30.45×10-6, and the w(V) is 181.80×10-6 to 229.20×10-6. All the samples show the characteristics of being rich in sodium and poor in potassium, relatively enriched in light rare earth elements, relatively depleted in heavy rare earth elements, and being enriched in large ion lithophile elements (LILE) such as Rb, Th, U, and K, and relatively depleted in high field strength elements (HFSE) such as Nb, P, and Ti. The values of Nb/Ta and Rb/Sr are close to the mantle average values. The petrogeochemistry indicates that the magmatic source regions of the quartz diorite, granodiorite and their enclaves have mantle-source characteristics. The εHf(t) values of the zircons in the Yueshandong pluton are -3.2 to 2.4, with single-stage model age (TDM1) and two-stage model age (TDM2) of 1 004 to 746 Ma and 1 991 to 1 442 Ma, respectively, and its initial magma originated from the depleted mantle or the newly formed lower crust. The elliptical to circular shape and lack of baking rims of the dark microgranular enclaves, coupled with weak fractional crystallization trends, point to magma mixing. It is speculated that these dark enclaves in the Yueshandong and the Mingnandong plutons represent residues of the magma mixing process. The granitic magmatism in the study area during the Early Jurassic was likely formed in an active continental margin setting related to the subduction of the Paleo-Pacific plate.

 The accurate prediction of reservoir brittleness is of great significance for underground geotechnical engineering disaster warning and oil and gas extraction. A brittle intelligent prediction method is proposed based on the acoustic emission signals generated during rock compression and fracture. Four types of rocks with the same size but different brittleness were experimentally prepared for indoor uniaxial rock fracturing, and the collected fracture signals were preprocessed to create a sample dataset. To address issues such as insufficient training data and limitations of traditional data augmentation methods, an improved deep convolutional generative adversarial network (DCGAN) is proposed. A deep convolutional attention generative adversarial network model based on spectral normalization (CS-DCGAN) is designed to output high-quality time-frequency images of samples, enrich the original sample dataset, and serve as input for the residual network; Extracting, learning, and iteratively training effective information from images to establish an intelligent brittleness prediction model, and continuously adjusting the hyperparameters of the model to improve its prediction accuracy; Finally, a multi-criteria evaluation is performed. The experimental results show that compared with traditional DCGAN, the improved model generates higher sample quality, with a minimum Frechet inception distance (FID) of 67.96, which can alleviate overfitting and improve the performance of the residual network. The average recognition accuracy for different brittleness can reach up to 94.95%, proving the effectiveness of the proposed method.

Cu polymetallic deposits are developed in the Bolishuangxing area, Heilongjiang Province. The ore-forming rock masses (granodiorite and granodiorite porphyry) are closely related to Cu deposits. In order to determine its mineralization era and geodynamic background, based on field survey work, this paper investigate the petrographic, chronological, and geochemical characteristics of intrusive rocks in Cu deposits of Bolishuangxing area, and explores the formation age, petrogenesis, and tectonic background of the intrusive rocks in the study area.The results show that the LA-ICP-MS zircon U-Pb products of Late Mesozoic Early Cretaceous magmatic activity (granodiorite at (120.94 ± 0.70)Ma, granodiorite porphyry at (120.88 ± 0.61)Ma ), which indicates that the formation time in Cu deposits of Bolishuangxing area was approximately 120.9 Ma, consistent with the peak period of mineralization in the region. Research on rock geochemistry shows that granodiorite and granodiorite porphyry contain(w(SiO₂)(61.04%-67.08%), w(Al₂O₃)(14.07%-15.86%), w(Na₂O+K₂O)(6.40%-7.15%),w(TFeO)(4.52%-6.69%), w(CaO)(2.30%-4.43%), δEu(0.74-1.27)), the europium anomaly is not obvious. They are enriched in light rare earth elements and large ion lithophile elements(Rb, Ba, Sr, etc.), and relatively deficient in heavy rare earth elements and high field strength elements (Nb,Ta,Zr, etc.). The magma source area is partial melting of newly enriched lower crustal material, showing I-type granite characteristics. Based on relevant research results, it is considered that the geodynamic setting of the formation of granodiorite and granodiorite porphyry in the study area is an extensional environment formed by the subduction and retreat of the ancient Pacific plate towards the Eurasian continent.

 In order to solve the problems of fault system development, formation fragmentation, rapid spatial variation of thickness, and difficulty in fine stratigraphic division and correlation in a certain area of western depression of Liaohe basin, the corresponding relationship between different stratigraphic fine divisions and correlation methods, such as traditional stratigraphic division and correlation methods. Vail classical sequence stratigraphy and high-resolution sequence stratigraphy, was determined first. On the basis of clarifying the sedimentary genetic model, the key wells are optimized, the stratigraphic subdivision scheme is determined, and the geological and geophysical information is fully excavated. The high-precision isochronous stratigraphic framework of single-layer level in the target layer of the study area is established by using the information of strong reflection of seismic event, lithology change of coring wells, sedimentary cycle, conductivity curve, resistivity curve value change, and fine secondary interpretation results of logging. The correctness of stratigraphic subdivision results is verified by using different single-layer top surface structure maps. The results show that the Yulou Oil-bearing sets in the study area can be divided into 29 short-term base level cycles (single layers), which correspond to the high resolution sequence stratigraphy and medium-term base level cycle(geological age 0.01 Ma). The band developed formation is generally in the direction of NE-SW, and the local highs are in a dome shape, mainly affected by sedimentation and differential compaction.

 The timing of lithospheric thinning and cratonic destruction in the Eastern North China craton (NCC) during the Mesozoic remains controversial. This study investigates the petrogenesis and tectonic environment of the Linjiagou pluton in the Liaodong Peninsula using petrology, zircon U-Pb dating, zircon Hf isotopes, and geochemistry. The Linjiagou pluton, composed primarily of medium-fine grained biotite-bearing monzogranite, formed at (220.8±1.2) Ma. Geochemically, the granite exhibits high SiO2(w(SiO2) = 69.24%-71.33%) and total alkali (w(Na2O+K2O)=8.37%-8.64%) contents, low MgO contents (w(MgO)=0.45%-0.60%), enrichment in large ion lithophile elements (e.g.,Rb,K,Ba,Th), depletion in high field-strength elements (e.g.,Ta,Nb,P,Ti), right-inclined REE patterns ((La/Yb)N average= 20.12), and negative Eu anomalies (δEu=0.38-0.46). Zircon Lu-Hf isotopes reveal negative εHf(t) values (-18.1 to -12.7), suggesting a parental magma source from partial melting of ancient crust. These geochemical characteristics suggest a within-plate post-orogenic extension environment, potentially related to the collision between the Yangtze craton and the North China craton. The widespread Late Triassic magmatism in the Liaodong Peninsula suggests that the decratonization of the NCC may have begun during this period.

The Qimantage area is one of the important metallogenic belts in China, known for large scale deposits of Fe-Cu-Pb-Zn-W-Sn-Au-Co and other polymetallic mineral. The Nalingguolehexi area, located in the eastern section, is particularly rich in iron, copper, and zinc skarn polymetallic minerals. However, exploration and research of polymetallic minerals in the area are hampered by thick gravel, stones and sand dunes, limiting geological and geochemical measurement methods. This article focuses on the magnetic anomaly zones (M1 and M3) ofthe Nalingguolehexi (Naxi)  iron polymetallic ore. Using Surpac three-dimensional modeling software, three-dimensional solid models of each ore-controlling geological elements were established. Through advanced three-dimensional visualization technology, geological structure models were constructed. By integrating and analyzing abundant geological data, the spatial distribution laws of ore bodies and their spatial relationship with mineralization structures were clarified. This enhanced understanding of mineralization laws allows for a transparent view of the key Naxi area down to 1 500 m and identifies eight deep marginal prospecting target areas, supporting mineral resource prediction, evaluation, and exploration planning in the Naxi mining area.

The ore-bearing rock mass of Xiaogushan gold deposit in western Liaoning is a suit of pyroclastic rock assemblage, which was originally divided into Yixian Formation of Lower Cretaceous of Mesozoic. In order to accurately determine the age of this rock body, and to explore the petrogenesis and tectonic significance of the rocks in the western part of the Liaoxi region, petrography, LA-ICP-MS zircon U-Pb dating and petrogeochemical analysis were carried out on the ore-bearing tuff of the Xiaogushan gold deposit. The results show that the weighted average age of the tuff is 2 510.7-2 508.9 Ma, which is the product of Late Neoarchean magmatism. The geochemical characteristics of the major elements show that the tuff is rich in silicon (w (SiO₂) is 68.99%-71.82% ), rich in alkali and potassium (w (Na₂O+K₂O) is 7.13%-8.82%, w (K₂O) is 6.94%-8.59%), poor in magnesium (w(MgO) is 0.51%-0.66%), and poor in calcium (w (CaO) is 0.43%-0.90%). The aluminum saturation index (A/CNK) ranges from 1.16 to 1.42, which belongs to the peraluminous calc-alkaline shoshonite series rocks. The rocks are enriched in LREEs and LILEs such as Rb, Th, U, K and Pb, and depleted in HREEs and HFSEs such as Nb, Ta and P. The rare earth distribution pattern shows a right-leaning gentle low “V” curve, with obvious fractionation of light and heavy rare earth elements. (La/Yb)_N is between 15.19 and 38.23, with weak Eu anomaly (δEu is 0.60-0.72). Petrogenesis and magma source discrimination show that the rocks have the characteristics of S-type granite, and the magma originated from the partial melting of metamorphic mudstone in the lower crust. Combined with the regional tectonic evolution, tectonic discrimination and geochronological characteristics, it is believed that the ore-endowed tuffs of the Xiaogushan gold deposit were formed in the tectonic environment of syn-collision after the subduction of the Longgang block and the Langlin block in the eastern part of the North China craton, which reflects the formation and evolution of the consolidated basement of the North China craton in the Archean period, and provides evidence for the tectonic mechanism of the North China craton in the Archean.

 Groundwater is the main source of production and living water for local rural residents in Chaoshan area，Guangdong Province. However, as a prominent groundwater environmental problem in recent years, the acidic shallow groundwater has had different degrees of impact on the health of residents and the balance of ecological environment. In this study, the groundwater drinking water source area in Fenghuang Town, Chao’an district was taken as the study area. The spatial and temporal distribution characteristics, hydrochemical types, characteristics and formation mechanism of pH value of acidic shallow groundwater in groundwater drinking water source area were analyzed by means of mathematical statistics and hydrochemistry. The results show that the groundwater in the study area has the characteristics of weak acidity and low total dissoloved solid （TDS）, and the hydrochemical types are mainly HCO3-Na type and HCO3-Na·Ca type. The rainfall in the study area is acidic as a whole, and there is no obvious pollution source related to pH change in the surrounding area. pH value is obviously affected by water-rock interaction and cation exchange. The weathering of silicate minerals and the dissolution of CO2 are the main sources of HCO3-. The dissolution and leaching of granite is the main source of H+. In summary, the acid shallow groundwater in the study area is mainly affected by acid rain leaching, leaching in aquifer media and cation exchange. In this study, through the analysis of the distribution characteristics and formation factors of acidic groundwater in the groundwater drinking water source area of Chaoshan area, it is of great significance to the rational utilization and development of shallow groundwater and the protection of groundwater resources.

Aiming at the problem of the in-situ stress field in long and deep buried tunnels, taking the deep buried tunnel of  Yellow River to Xining diversion project in Qinghai Province as the background, the regional tectonic evolution analysis, on-site hydraulic fracturing testing, and numerical deduction methods were used to determine the in-situ stress characteristics of each section of the tunnel. The research results show that the tunnel of  Yellow River to Xining diversion project is affected by the compression movement of the blocks in the northeast margin of the Qinghai-Xizang Plateau, and the main compressive stress direction is NE-NEE direction; The stress field of the tunnel  can be divided into three regions, with the maximum horizontal principal stress lateral pressure coefficient of 2.0 in the Laji section; The maximum buried depth of the tunnel when crossing the Laji Mountain exceeds 1 400 m, and the maximum horizontal principal stress exceeds 70 MPa, which may have a significant impact on the stability of the tunnel surrounding rock.

 Urban road collapse is a serious safety issue in urban areas that can result in casualties and transportation disruptions, threatening urban operations and social development. Accurately predicting urban road collapse and analyzing its spatial and temporal dynamics are of great significance for urban safety. In this study, we focused on Futian District in Shenzhen City, Guangdong Province as the study area. We developed a model to predict the susceptibility of urban road collapse by integrating multi-source remote sensing data with the random forest algorithm. Additionally, we examined the primary indicators affecting the prediction performance of the model and the primary factors influencing the vulnerability of urban roads to collapse. The spatiotemporal prediction results of urban road collapse susceptibility show that the urban road collapse susceptibility prediction model, constructed by combining optical data and radar data, can predict the spatial and temporal changes of road collapse susceptibility  accurately. The predicted coefficient of determination is 0.65, indicating high prediction accuracy. From 2017 to 2022, the risk of roadway collapse in Futian District exhibited an overall increasing trend. There was a decrease in the area of zones with very low and low susceptibility, and an increase in the area of zones with medium and high susceptibility. The results of the random forest feature importance analysis indicate that the texture features extracted from image data make a significant contribution to the prediction model. Based on the geodetector results, it is known that population, GDP, and underground facilities are three key factors influencing urban roadway collapse.

The pore structure of low-permeability sandstone is complex. The three-dimensional (3D) quantitative characterization of micro-nano scale fluid flow characteristics and the analysis of occurrence mechanisms are of great significance for fine reservoir description and enhanced oil recovery. Two water-wet sandstone samples with similar micro-pore structure characteristics from the upper Es₄ Member in G Oilfield were selected, and X-ray CT coreflooding experiments under relatively low and relatively high flooding rates were performed. The distribution of oil, water and particle phases in 3D pore space at different water flooding stages was obtained by image processing technology. The occurrence states and changes of oil phases in 3D pore space and individual pores during the water flooding process were discussed. In addition, combined with the finite volume method, the fluid flow characteristics under the control of multiple factors (e.g. microscopic pore structure heterogeneity, displacement mode and waterflooding rate) were also determined. The results indicate that the large and continuous oil drops were broken up and gradually separated into small oil droplets during the water flooding process, and the small oil droplets distributed in a discrete state in the 3D pore space. After water flooding, the connectivity of oil droplets becomes poorer and the geometry becomes smoother and more regular. The dominant fluid flow channels are generally well developed in the sandstones with strong microscopic heterogeneity and good pore connectivity, resulting in the development of the flow around and crossflow behaviors. Therefore, the water sweep efficiency in the sandstones with strong microscopic heterogeneity is low. The water flooding rate is also an important factor affecting the oil displacement efficiency and oil/water migration path. Increasing water displacement rate can significantly increase the number of water injection capillaries, thus enhancing oil recovery rate. This study also indicates that the oil displacement efficiency of low-permeability sandstones can be effectively improved by increasing the oil-water viscosity ratio and the injected capillary number under an appropriate interfacial tension. The research results provide an important theoretical basis for enhancing oil recovery (EOR) of low-permeability and water-wet sandstone reservoirs.

The western slope of Songliao basin is an important oil sands metallogenic belt in China. In order to further clarify the characteristics of Cretaceous oil sands resources in the central and southern parts of the area, the basic geological survey work has been implemented with five oil sands investigation wells and one hydrological investigation well in the Dagang area of Jilin. Based on core observation, geophysical log interpretation, and oil content test of core samples, a comprehensive geological study was carried out. The results show that, the oil sands of the Cretaceous Yaojia Formation are located at a depth from 175 m to 208 m, and the lithology is mainly siltstone and fine sandstone. The oil content level of the core reaches oil immersion grade, with a maximum oil content of 16.02% and an average oil content of 8.23%. The oil sand formation logging curve is characterized by low natural gamma value, high acoustic velocity value, medium to high resistivity and low density. The oil sands formation is divided into four sub-layers (S1, S2, S3, S4) and oil content characteristics are analyzed. Vertically, the oil content is non-homogeneous and increases gradually with depth. The average oil content of S3 and S4 in the lower part of the reservoir is 10.80 % and 11.40 %, respectively, reaching the grade of rich ore. The effective thickness of each sub-layer varies widely in the vertical direction, with a maximum value of 3.10 m and a minimum value of 1.20 m. The average effective thickness of the lower S3 and S4 sub-layers is 2.90 m and 1.90 m respectively, which is obviously better than the upper S1 and S2 sub-layers. On the scale of oil-sand development, the distribution area of S3 sub-layer is the largest, and the area of sand body with effective thickness≥2 m is about 270 m×160 m, and the thickness center is located in the southeast of the well area, and the thickness is thinned from the thickness center to the northwest; The distribution area of S4 sub-layer is the second largest, and the area of sand body with effective thickness≥2 m is about 250 m×120 m, its thickness center is located in the middle of the well area. In terms of planar spreading, its distribution area is large in the southeast and northwest directions, and the distribution area in the middle zone is slightly smaller, with a nearly dumbbell shape, the thickness thins from the thickness center to the north-east and south-west directions. On sand deposition characteristics, controlled by the sedimentary evolution of the regional shallow water delta, high-quality oil sands are mostly deposited in the fine sandstone of the divergent river channel, especially the S3 and S4 sub-layers located in the lower part of the reservoir have obvious deposition patterns of multi-phase superimposed river lateral accumulation sand bodies. In general, the S3 and S4 sub-layers have high oil content, large effective thickness and considerable spreading area, and are the main reservoir of high-quality oil sands in the area.

Iron containing minerals are earth-abundant, low cost, and able to tragger H₂O₂ and persulfate (PS). Biotite contains Fe²⁺ and has reducing properties, and there are limited studies on its activation of PS to remove pollutants. In this study powdered biotite (PB) was used to activate PS for degradation of a reactive azo dye, reactive green 19 (RG19). Results showed that PB was able to efficiently activate PS to produce OH· and SO₄^-·, which were responsible for the degradation of RG19. Approximately 95% of 5.0×10^-5 mol/L RG19 was decolorized in 15 min and azo bonds were completely broken down under the conditions of 5.0×10^-3 mol/L PS,1.0 g/L PB, initial pH 6.0, and 55 ℃. Decolorization process followed a pseudo-second-order (PSO) kinetics. The American dye manufacturers institute (ADMI) color scale and total organic carbon removal were both taken in consideration and the oxidative degradation efficiency at 98.2% and 71.2%, respectively. The high activation energy of 34.96 kJ/mol indicated that the reaction was significantly affected by temperature. PB can be used as an efficient activator for PS to degrade dye wastewater.

 Microseismic event recognition is a key part of the data processing of hydraulic fracturing microseismic monitoring, but there are some limitations in effective event feature extraction and noise resistance for current microseismic event recognition methods based on deep learning, which cannot meet the requirements of subsequent microseismic source localization and inversion. In this paper, a microseismic event recognition method based on an improved U-Net model is proposed. In this method, residual shrinkage modules are introduced during the downsampling process of U-Net. The residual blocks are used to implement shortcut connections of the network structure to reduce the loss of feature information during model training, and the soft thresholding shrinkage technology is combined to weaken the interference of noise features in microseismic data and enhance model noise resistance. The attention gate mechanism is introduced during the upsampling process to weight the extracted microseismic data feature vector by gating signal, so that the model focuses on the area of the data containing microseismic events, thereby improving the extraction ability and identification accuracy of the model’s effective feature. The experimental results of synthetic and actual microseismic data show that the proposed method can adequately extract the characteristics of effective microseismic events. Compared with the traditional convolutional neural networks and residual networks, it  can recognize microseismic events more accurately,  the accuracy of test datasets is improved by 6.28% and 3.70% respectively.   Especially for  the  recognition accuracy of  microseismic signals with weak energy,it is higher than that of similar network models. And it has better noise resistance and generalization ability.

 Studying the characteristics and genetic mechanisms of structural fractures and predicting their distribution patterns are of great significance for guiding the exploration of volcanic gas reservoirs. This article focuses on the volcanic rocks of the Huoshiling Formation in Chaganhua subsag of Songliao basin. By comprehensively utilizing data of structural evolution, rock cores, imaging logging, rock physics experiments, and faults, the characteristics of structural fractures are analyzed to determine their formation periods. A three-dimensional geological model of the study area is established, and stress field simulation is carried out using the geostress module of Petrel software. The results show that structural fractures are mainly formed during the fault depression and inversion periods. Fractures formed during the fault depression period have high inclination angles and are mostly filled, they are mainly ineffective fractures. Fractures formed during the inversion period have low inclination angles and are partially filled, they are mainly effective fractures. Fractures formed during the inversion period cut through the fractures formed during the fault depression period. The maximum principal stress during the inversion period is horizontal principal stress, with a direction near east-west direction and a maximum stress value of 114.5 MPa. During the fault depression period, the maximum principal stress is vertical principal stress, with a direction near north-south direction. The stress field simulation results show that the current maximum horizontal principal stress direction is roughly east-west, consistent with the regional compressive stress direction. During the fault depression period, the maximum horizontal principal stress direction is roughly north-south, and the stress direction is basically consistent with the fault strike; The geostress is biased by the influence of faults. In areas with dense fault distribution, the stress direction is disorderly. In areas with sparse fault distribution, the stress direction is basically consistent with the principal stress direction. At the end of the fault, there is a clear phenomenon of stress concentration. It is concluded that effective fractures can be developed in areas with high maximum horizontal principal stress values, which can improve reservoir permeability. Therefore, drilling should be carried out in areas with high stress values and basically consistent stress directions.

 The Xin’antun molybdenum deposit in central Jilin Province, located within the Lesser Khingan-Zhangguangcai Range metallogenic belt, features simple stratigraphy with widespread distributed granodiorite, monzonitic granite and alkali granite in the southwest part of the mining area. During the early Yanshanian, frequent tectonic and magmatic activity, driven by the subduction of the Paleo-Pacific plate, facilitated molybdenum mineralization. The ore bodies, hosted in granodiorite and controlled by NE-trending faults, are mainly quartz veinlet-stockwork and veinlet-disseminated types, belonging to quartz vein-porphyry molybdenum deposit. To assess the prospecting potential comprehensively, this paper integrates geological characteristics with physical and chemical exploration data. Principal component analysis of soil geochemistry shows multi-stage metallogenesis from high temperature to medium-low temperature and indentifies a target area based on combined anomalies of Mo, W, Cu and Bi. Electric and magnetic surveys show magnetic anomalies correlating with distribution of the rock bodies and strata; Fault zones show positive and negative magnetic anomalies. Medium-high-resistivity and high-polarisation induced polarization anomalies delineate ore bodies and mineralised zones. Electrostatic bathymetry, combined with geological sections, confirms the shallow ore bodies are within a high-polarisation body, extending at depth, indicating potential for large-scale porphyry molybdenum ores. This comprehensive geological, physical and chemical exploration indentified 4 prospective metallogenic zones.

Based on the abundant seismic, wells and geochemical data, studies were carried out on the formation mechanism and hydrocarbon accumulation controlling factors of sublacustrine fans of the third member of Dongying Formation in LD10 structural area, Liaozhong depression, Bohai Bay basin, and the hydrocarbon enrichment regularity was discussed. According to the research, the “chain island” type paleogeomorphology of Liaoxi uplift controlled the source condition, and the area near the main sand passages had a better development environment with bigger thicknesses and more periods. Single event fans and external configuration fans were confirmed by borehole seismic calibration, and boundary description methods were established by integration between geology and geophysics.  The deep structural background, the distance between the fans and source rock, and the pattern between the fault and the fans jointly controlled the hydrocarbon charging intensity in the LD10 structural area. Under the conditions of double deep ridges, smaller distance from the main source rock layers, and forward charging from fault to fans, the goal fans could form high hydrocarbon columns. These new understanding and methods were used to guide the exploration practice, with LD10-6 medium-large sublacustrine fans oilfield discovered in the Dongying Formation in the western slope of Liaozhong depression, which is a breakthrough in the exploration of sublacustrine fan of Paleogene in Bohai sea area.

The direct current resistivity method, as one of the important methods in geophysical exploration, has played a significant role in various geological exploration fields. This paper conducts a study on the electrical response characteristics of intrusive rock models using a three-dimensional direct current numerical algorithm based on space-wavenumber hybrid domain. The total electric field normalization coefficient T₃ is introduced, and the electric field response characteristics of pole-dipole array and dipole-dipole array configuration of non-mineralized and mineralized intrusive rock models are comparatively analyzed. Special consideration is given to the effects of isotropic and anisotropic mineralization zones, as well as the induced polarization effect, in order to reveal the response differences under different electrical conditions. The analysis results show that the total electric field normalization coefficient has a more pronounced response to the underground medium than electric field components. The T₃ response anomaly detected by dipole-dipole array is superior to that of pole-dipole array, and different electrical mineralized zones exhibit significant differences in T₃ response features. Compared to polarizability anisotropy, resistivity anisotropy has a more profound impact on the observation results. The response characteristics of the mineralized model are far more complex than those of the non-mineralized model, especially when the mineralized zone is electrically anisotropic, the observed T₃ morphology of different electrical parameters is quite different.

 Aiming at the deficiency that it is over subjective to determine index weights in the regional groundwater pollution risk assessment system, this paper takes Shallow groundwater in Baoding plain, Hebei Province as the study area, using random forest algorithm to construct the mapping relationship between groundwater pollution risk assessment indicators and nitrate concentration in order to optimize the weights of each index，and on this basis, the risk of groundwater nitrate pollution in shallow groundwater in Baoding plain is evaluated. The results show that when the number of decision trees is 130, the minimum sample number required for decision tree splitting is 82, and the maximum depth of decision trees is 2, the optimal weight is obtained. The results showed that the depth of groundwater level, types of vadose zone media, the net recharge rate of groundwater, and the ratio of cultivated land area account for larger weights, with weights of 5.00, 4.20, 4.14, and 3.40 respectively. The Spearman correlation coefficient between groundwater nitrate pollution risk assessment results and measured groundwater nitrate concentration has significantly increased based on random forest method, and the prediction accuracy was improved by 25.6%. 

Ground subsidence, a slowly occurring and irreversible geological disaster, is an environmental geological problem which commonly occurs in the process of urbanization. In order to solve the problems of incomplete subsidence information obtained by the existing ground subsidence monitoring network and the lack of precision in monitoring urban ground subsidence, it needs to be optimized. In this paper, taking the ground subsidence monitoring network of Nanjing Yangtze River floodplain as an example, using the regionalized variable theory of geostatistics and the variational function theory, Kriging interpolation method is used to establish the variational function model for the ground subsidence monitoring network of the study area, and the standard deviation distribution characteristics of each monitoring network of the Yangtze River floodplain in Nanjing area are investigated for the optimization of the deployment. The results show that the ground subsidence monitoring networks in the study area has the problem of unreasonable distribution. After the optimization, 34 redundant and marginal monitoring wells are eliminated and 16 new monitoring wells are added; 49 redundant and marginal level points are exempted and 21 new level points are added; 18 groups of stratified settlement monitoring network are eliminated and 13 groups of stratified settlement monitoring points are added. The improved monitoring well network can maximize the acquisition of monitoring data while meeting the accuracy requirements, and efficiently optimizes the arrangement of the settlement monitoring network, with reasonable results.

The fracture conductivity is an important index to determine the fracturing effect of deep coalbed methane reservoirs. The three-dimensional digital core of a deep coal-rock reservoir in Daning block was constructed by using high-resolution CT scanning technology and the advanced mathematical algorithm of Avizo visualization software, and the microscopic pore structure characterization of different types of coal-rock reservoirs was carried out from multiple dimensions. On this basis, the linear flow fracture conductivity experimental device was used to evaluate coal rock fracture conductivity. The effects of proppant particle size, sanding concentration, different proppant particle size combinations, closure pressure, proppant embedding and pore throat structure on the fracture conductivity of coal rock were systematically studied. The results show that the pore structure characteristics of different types of coal rock samples in the study area are significantly different. The distribution form of pore throat is mainly continuous or isolated. The pore radius is distributed primarily in 5.23-34.85 μm, the throat radius is mostly 1.31-12.27 μm, and the pore throat coordination number is small. With the decrease in permeability, the connectivity of the pore throat worsens and the heterogeneity strengthens. The fracture conductivity under the support of large particle size proppant is stronger, but the fracture conductivity under the support of small particle size proppant is more stable. The fracture conductivity increases significantly with the increase of sanding strength but decreases with the increase of closure stress. When the propping agent is embedded in the coal and rock strata, the flow space of the fluid in the fracture will be compressed and blocked, and the fracture conductivity can be decreased by 12.2%. Under different proppant particle size combination ratios, the higher the proportion of large particle size proppant, the greater the conductivity. In general, the main controlling factors of fracture conductivity of coal-rock pressure in this area are sanding concentration, proppant particle size, and fracture closure stress.

Shale oil in-situ mining technology has many advantages and can effectively improve mining efficiency. However, the operating conditions for shale oil in-situ mining are harsh, and the pipes used in these conditions will experience severe high-temperature corrosion over a long period. Hence, the material selection is key to a safe and effective in-situ shale oil exploitation. In this study, common oil well pipe materials J55, P110, and 3Cr were selected as research objects. Microstructural characterization, cross-sectional observation, and oxidation kinetics curve were used to study their high-temperature corrosion resistance performance at 600 ℃. The research results show that with the increase of corrosion time, the thickness of the oxide film on the surface of the three samples increases, the J55 has the thickest oxide film, and the 3Cr has the thinnest. Secondly, the oxidation weight gain of the three samples increases with the extension of corrosion time, the J55 has the highest oxidation weight gain, and the 3Cr has the lowest. Finally, the surface products of the three samples all contain Fe₂O₃, and the surface of 3Cr also has chromium oxide. The above results indicate that the 3Cr has the best high-temperature corrosion resistance performance among the three materials. In the high-temperature underground environment of shale oil in-situ mining, the chromium content is an important reference for material selection.

In order to provide evidence for the Neoproterozoic great oxidation event on the northern margin of the North China craton, this paper investigates the sedimentary environment of the Nanfen Formation in Tonghua area. Petrology, geochemistry, and isotope geochemistry have been used on marlstones and shales to explore the tectonic setting, the degree of oxidation and reduction, and its response to the Neoproterozoic great oxidation event. The results show that the Nanfen Formation is composed of purple and yellow-green shales and marlstones, with marine sedimentary characteristics. Ni/Co ratio, V/Cr ratio, V/(V+Ni) ratio, Mo content, and total organic carbon content indicate that the sedimentary environment was oxidized during the forming period of Nanfen Formation. The oxidation degree of the Nanfen Formation fluctuated in the early evolutionary stage, and remained stable in the late stage. This proves that the Neoproterozoic great oxidation event occurred on the northern margin of the North China craton and responded well to the Neoproterozoic great oxidation event in South China.

 As critical strategic mineral resources, dispersed metals play an irreplaceable role in national economic development, security, and technological innovation. They serve as fundamental supports in cutting-edge fields such as high-tech industries, precision manufacturing, clean energy, and next-generation information technology. Constrained by their geochemical properties, these elements typically occur in a highly dispersed state in nature, seldom forming independent minerals and instead mainly existing as associated components hosted in major metal minerals. Within Pb-Zn deposit systems, sphalerite is widely recognized as a key host mineral for critical dispersed elements such as gallium (Ga), germanium (Ge), cadmium (Cd), and indium (In). This paper systematically reviews recent research advances on the enrichment patterns of dispersed elements in Pb-Zn deposits, with a focus on elucidating their occurrence states and enrichment mechanisms. Studies indicate that elements such as Ga, Ge, Cd, and in primarily occur in an isomorphous form within the crystal lattice of sulfide minerals like sphalerite, while independent minerals are extremely rare and generally negligible in abundance. Specifically, Ga, Ge, and In tend to couple with ions such as Cu+, Ag+, and Fe2+ to jointly replace Zn2+ in sphalerite, whereas Cd, due to its geochemical similarity to Zn, can directly substitute for Zn2+ in the crystal lattice. Consequently, sphalerite becomes the most significant host for these dispersed elements. It is noteworthy that elevated iron content in sphalerite significantly inhibits the isomorphic substitution of Cd, demonstrating the strong influence of crystallochemical conditions on its enrichment behavior. Additionally, Ge can occur isomorphously in silicate minerals such as quartz. From a regional metallogenic perspective, the concentrations of dispersed elements vary considerably among different genetic types of Pb-Zn deposits. Even within deposits of similar geological settings, their spatial distribution often exhibits pronounced heterogeneity. In terms of enrichment environments, Ga, Ge, and Cd are more readily enriched in low-temperature hydrothermal Pb-Zn deposits, whereas In is predominantly concentrated in intermediate- to high-temperature magmatic-hydrothermal systems or tin-bearing polymetallic Pb-Zn deposits. In terms of research methodology, modern microanalytical techniques, particularly electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), have played a pivotal role. With their high spatial resolution and in-situ analytical capabilities, these techniques enable precise characterization of the occurrence and spatial distribution of dispersed elements in minerals at the nanoscale, thereby providing indispensable technical support for understanding their geochemical behavior and enrichment mechanisms. Future research should focus on key scientific issues such as identifying the material sources of dispersed elements, understanding their migration forms in ore-forming fluids, clarifying precipitation mechanisms, and deciphering their coupling relationships with the mineralization processes of major metals. Such efforts will deepen the understanding of the super-enrichment mechanisms of dispersed elements and provide theoretical guidance for integrated exploration and efficient utilization.

 The boundary layer fluid and its viscosity changeshave a significant impact on the flow of fluids in low permeability media. Existing low-velocity non-Darcy flow models usually ignore the change of fluid viscosity, or simply treat the fluid viscosity as a function of pore radius. The viscosity of boundary layer fluids is usually related to contact angle. In this paper, based on capillary model and fractal theory, a new low-velocity non-Darcy flow model is proposed considering the influence of contact angle on the viscosity of boundary layer fluid. The reliability of the model was verified through experiments and the sensitivity analysis of key parameters was conducted. The results show that the contact angle has a significant impact on the viscosity of the boundary layer fluid, which in turn affects the flow behavior of the fluid. After considering the change of fluid viscosity in the boundary layer, the flow velocity decreases. In this experiment, compared with ignoring the change of fluid viscosity, the decrease in flow velocity can reach 57.1%. The flow velocity decreases with the increase of fractal dimension of pore distribution (Df) and increases with the increase of contact angle. In this paper, under the same pressure gradient, when Df increases from 1.2 to 1.8, for every 0.2 increase, the flow velocity decreases by 18.4%, 23.3%, and 29.1%, respectively; When the contact angle increases from 0° to 80°, for every 20° increase, the flow velocity increases by 10.9%, 12.3%, 14.0%, and 16.3%, respectively. As the pressure gradient increases, the boundary layer fluid participates in the flow, and the effective seepage section and fluid effective viscosity increase. The increase of fluid viscosity has retarding effect on the flow, but the effect is smaller than the gain effect of the increase in flow section on the flow velocity. Therefore, in general, the flow velocity increases with the increase of the pressure gradient.

High resolution is one of the goals of seismic data processing. Inverse Q filtering is a common method to achieve high resolution of seismic data. When the signal-to-noise ratio (SNR) of seismic data is low, the conventional stable inverse Q filtering method has the challenge of enhancing the noise energy. In this paper, an inverse Q filtering method with adjustable amplitude compensation operator under SNR constraints is proposed based on self-adaptive gain-limited inverse Q filtering method. This method presents a new amplitude compensation operator. By calculating the SNR of seismic data, the cutoff frequency of the effective frequency band is obtained, enabling the amplitude compensation operator to be dynamically adjusted according to the characteristics of the seismic data itself. The high-frequency noise energy is further suppressed by introducing a dynamically adjustable amplitude compensation curve. The test results of theoretical synthetic data and field data show that: the method proposed in this paper can compensate the amplitude well and improve the seismic data resolution. Compared with the traditional stable inverse Q filtering method and the self-adaptive gain-limited inverse Q filtering method, the method proposed in this paper has a better ability to suppress noise energy enhancement, and the SNR of the processing result is higher.

 Due to the limitation of acquisition conditions and costs, the pre-stack seismic data may be irregularly distributed or incomplete in space, which  brings difficulties to the subsequent processing and interpretation of seismic data. In recent years, the convolution neural network method widely used in the reconstruction of missing seismic data lacks attention to the global information, while the network model with multiple downsampling brings low-frequency signal loss, and the reconstruction results of the low-amplitude missing part still need to be further improved. Therefore, this paper proposes a multi-scale feature self-attention model. A multi-scale wavelet fusion block based on the self-attention mechanism is designed at the bottleneck of the U-Net backbone network, and the outputs of all encoders are fused by discrete wavelet transform and self-attention mechanism, which effectively balances the global and local feature processing and reduces the signal loss caused by downsampling. A multi-scale receptive field is inserted into the network to improve performance and enhance spectral learning of different frequencies by learning multi-scale features for different degraded data. Compared with the classical reconstruction methods for seismic data, the reconstruction results of the algorithm in this paper are improved in both qualitative and quantitative assessments. On the synthetic dataset and the real dataset with 30% continuous missing  data,  the signal-to-noise ratios  of the reconstruction results   are 21.748 7  and 14.954 0 dB  respectively; On the synthetic dataset with 50% random missing and regular missing data, the signal-to-noise ratios of the reconstruction results are 28.832 0  and 37.724 2 dB  respectively.

 Through ongoing exploration efforts, the distributions of mineral resources within the upper 500 m have been largely mapped across most regions. However, over two-thirds of China’s territory is covered by complex terrain such as marshes, forests, deserts, and medium-to-high mountain ranges. Mineral exploration in these challenging terrains has reached a critical juncture requiring urgent breakthroughs. The airborne-ground-borehole gravity-magnetic multi-parameter detection technology   (encompassing raw field, component field, and gradient field measurements) forms a rapid breakthrough chain of ‘rapid delineation-detailed verification-precise targeting’. This constitutes an effective approach for the rapid and accurate exploration of mineral resources within complex terrain areas. This paper, guided by the exploration requirements for mineral resources in complex terrain areas, systematically outlines research advances in  principles, equipment, data calibration and processing, platform technologies, and inversion methods of  airborne-ground-borehole multi-parameter gravity-magnetic detection. We clarify the complementary hierarchical structure of aerial, ground-based, and downhole detection within the three-dimensional exploration technology system, elucidating its practical application logic and future development trends towards miniaturisation and intelligent operation. This provides technical reference for the upcoming strategic initiatives aimed at achieving breakthroughs in mineral exploration.

In order to prove the existence of water migration in ice under vibration loading and to investigate the law of water migration in ice, vibration tests were carried out under negative temperature conditions with artificial column ice as the research object, and the migration of liquid water in ice was investigated by changing the ambient temperature and loading frequency. First, in combination with the load characteristics of heavy fully loaded trucks borne by highways in permafrost areas, with 55 kPa as the load amplitude and the cyclic vibration frequency set to 2 880-28 800 times, the cyclic vibration loaded layered column ice water migration test was carried out under the conditions of －3 ℃, 0.5 Hz; Then, the vibration test was carried out under the conditions of -5 to the water migration test of artificial column ice under cyclic vibration loading was carried out at －1.0 ℃ and 0.1-0.5 Hz; Finally, the test data were fitted. The results show that: Under vibration loading, the liquid water in the ice migrates along the structural cracks in the loading direction; At different ambient temperatures, the amount of water migration increases exponentially; At different loading frequencies, the amount of water migration grows in stages in the form of a segmented function. When the loading frequency and load amplitude are constant, the amount of water migration and the peak growth rate increase with the increase of ambient temperature and decrease with the decrease of temperature, and the moisture migration measured at -1 ℃ is about 3.75 times of that at -5 ℃; The closer to the melting point, the faster the peak growth rate occurs, and the slower the opposite is. When the ambient temperature and load amplitude are constant, the moisture migration and the peak growth rate increase with the increase of frequency and decrease with the decrease of frequency, and the amount of water migration measured at 1.0 Hz is about 2.04 times of that at 0.1 Hz; The faster the loading frequency is, the faster the peak growth rate appears, and the slower the opposite is.

Understanding the formation and source characteristics of andesite in continental arc environments holds significant implications for revealing arc magmatism. This study focuses on the Suolun area of the Great Xing’an Range, using a combined approach of chronology and geochemistry to thoroughly investigate the genesis of trachyandesite and andesite in the region and their magmatic source characteristics. Zircon U-Pb dating indicates that the trachyandesite and andesite formed during the Early Cretaceous (134-129 Ma). The studied andesite and trachyandesite have SiO2 contents of 57.13% to 58.16%, total alkali (K2O+Na2O) contents of 6.10% to 6.40%, Al2O3 contents of 17.09% to 17.59%, TFe2O3 contents of 6.71% to 6.92%, and Mg# values of 41.52 to 43.94, featuring high-potassium calc-alkaline weakly peraluminous rock characteristics. These samples exhibit enrichment in light rare earth elements and large ion lithophile elements (such as K, Rb, Ba) and relative depletion in high field strength elements (such as Nb, Ta, P, and Ti), with a slight negative Eu anomaly (δEu=0.88- 0.89), indicating that they are products of continental arc magmatism. Additionally, both types of samples have high zircon εHf(t) values (5.81 to 11.29) and whole-rock εNd(t) values (0.6 to 1.3), suggesting that the intermediate magmas in the Suolon area originated from partial melting of a subduction-fluid-modified, depleted lithospheric mantle fluids.

The Shilu large-scale Cu-Mo skarn deposit in western Guangdong is situated along the northwestern margin of the Yangchun basin within the Yunkai area. The orebodies are predominantly hosted in skarn and skarnized marble at the contact zone between Early Cretaceous granodiorite and Lower Carboniferous strata, structurally controlled by NE-trending faults. To better understand the metallogenic processes, this study employs EPMA and LA-ICP-MS in-situ microanalysis methods, focusing on garnet and vesuvianite to investigate their elemental geochemical characteristics based on detailed detailed geological investigations. Analytical results demonstrate that: Garnet in the Shilu deposit is predominantly andraditic (Gro0-36And63-100), while pyroxene is overwhelmingly diopside (Hed0-14Jo0-6Di81-99); The mineral assemblage indicates early-stage fluid evolution occurred under high oxygen fugacity conditions;  Vesuvianite exhibits more complex compositions, primarily belonging to common vesuvianite with minor Al-rich, Mg-Al, and Mg-Fe varieties. Garnet formed in a weakly acidic, open-system environment characterized by high water/rock ratios and dominantly infiltrative metasomatism. Both garnet and vesuvianite mainly originated from magmatic-hydrothermal fluids associated with granodiorite and quartz diorite. During the transition from skarn to retrograde alteration stages, the fluid composition shifted from Fe3+-rich to Al-rich, accompanied by significant reduction in w(∑REE). This trend reflects changing physicochemical conditions (e.g., pH) and suggests the involvement of external fluids (e.g., meteoric water) into the open-system alongside magmatic fluids. Additionally, the study identifies considerable tungsten exploration potential but limited tin mineralization potential in the deposit.

As a common environmental pollutant, accurate determination of the bioavailability of arsenic is essential for assessing potential health risks. In order to evaluate the environmental quality of agricultural soils more rationally, this paper explores a reliable and efficient method to extract bioavailable arsenic （the sum of the water-soluble, weakly acid-extractable, reducible, and oxidizable fractions of arsenic）  from soil. Based on the property that L-cysteine solution can effectively form chelates with arsenic, L-cysteine solution was selected as the extractant, and optimized around the parameters of mass fraction of extractant, extraction temperature, and ultrasonic time, etc. The mass concentration of arsenic in the soil in the effective state was determined under the conditions of different extraction temperatures and different mass concentrations of the extractant, respectively, and compared with the results of the sequential extraction to determine the optimal extraction conditions. The results showed that when the mass concentration of L-cysteine was 10 g/L, the ultrasonication temperature was 40 ℃, and the ultrasonication time was 30 min, the bioavailable  arsenic extracted of  DT-1 sample was 7.37 μg/g, closely matched the results of bioavailable arsenic obtained by sequential extraction （7.83 μg/g）.  Compared with the sequential extraction method, this method requires only one step of extraction and the extraction time is shortened by 65 h, which greatly improves the efficiency.

The Benxi area, situated within the northeastern segment of the eastern block of the North China craton, represents a critical region for investigating Archean evolution and holds significant importance for understanding the formation and evolution of the Precambrian continental crust of the North China craton. To elucidate the petrogenesis and tectonic setting of the newly identified Liujiapuzi pluton in Benxi (within the Jiao-Liao-Ji orogenic belt), an integrated study of petrology, whole-rock geochemistry, and zircon U-Pb geochronology was conducted. The Liujiapuzi pluton is compositionally defined as porphyritic fine- to medium-grained biotite monzogranite, displaying metaluminous to weakly peraluminous characteristics and high-K calc-alkaline affinities typical of I-type granite. Geochemically, it exhibits enrichment in large-ion lithophile elements (e.g., Sr, La, Th) and depletion in high-field-strength elements (e.g., Nb, P), with a right-sloping REE pattern and negative Eu anomaly. Zircon U-Pb dating yields an emplacement age of ((2 518±21) Ma), indicating formation during the Late Neoarchean. Petrogenetic modeling suggests a hybrid magma source involving crustal assimilation with mantle-derived components, generated in an active continental margin environment characterized by oceanic subduction. This implies the Longgang and Langlin blocks of the eastern North China craton were not amalgamated at ((2 518±21) Ma). The Liujiapuzi pluton represents an early accretionary product distinct from the post-collisional Majiagou pluton ((2 490±21) Ma) in the same area. This event likely represents the last major magmatic episode before stabilization of the Archean basement in the North China craton.

 The accurate reconstruction of the formation and evolution of ancient ocean basins, as represented in the orogenic belts, constitutes an important research content in geotectonics. Focusing on the Meso-Tethys (Bangong-Nujiang suture zone) of northern Tibet, this study systematically examines the characteristics of ocean islands (seamounts) and therir geological significance in understanding paleo-oceanic basin dynamics. Ocean islands (seamounts) within orogenic belts exhibit not only widespread distribution but also remarkable diversity.In addition to the traditional hotspot-type ocean islands (seamounts), they also include slow- and fast-spreading mid-ocean ridge-type ocean islands (seamounts) and intra-oceanic arc-type ocean islands (seamounts). Their common characteristics are the development of ultrabasic-basic magmatic rock assemblages and pelagic colluvial conglomerates. Ocean islands (seamounts) are the main components of “oceanic crust fragments” in orogenic belts and serve as important carriers of information on the formation and evolution of ancient ocean basins. Particularly, they provide critical insights, particularly in revealing the nature of ancient ocean basins, reconstructing their convergence and termination processes, and analyzing the temporal duration of ancient oceanic crust. 

 With the depletion of shallow resources, refined exploration of deep metal deposits has become a key focus in geophysical prospecting. Underground electromagnetic (EM) methods demonstrate distinctive potential in deep mineral exploration owing to their proximity to target bodies, strong anti-interference capability, and high-resolution imaging. Internationally, these methods have been established as core technologies for exploring deep (>500 m) massive sulfide and disseminated deposits. This paper systematically reviews recent advances in borehole, crosswell, and borehole-to-surface EM methods both domestically and internationally, analyzing the developments of high-power transmitters, high-sensitivity receivers, and multicomponent observation systems, and summarizing numerical modeling, inversion algorithms, and intelligent data processing under complex well conditions. Within the workflow of deep mineral exploration, application strategies of underground EM techniques at different stages are summarized, including constraining metallogenic background, guiding metallogenic models, supporting target prediction, and locating ore bodies. Results indicate that underground EM methods are evolving toward multi-source integration and multi-parameter fusion, forming deep-exploration frameworks of “multi-parameter cascading with near-far integration” and “strong-source close-receiving with dense irradiation and wide-area coverage”, providing technical support for deep mineral exploration.

Due to the limitation of setting the upper boundary at the free surface located at the water table, the Theis well model in unconfined aquifers has some problems such as unsound theoretical basis and unreasonable physical meaning of parameters. To overcome these issues, firstly, the well model is revised by moving the free surface from the water table to the air entry plane, and takes the Boussinesq equation located at the air entry plane as the governing equation, and derives the analytical solution of the model; Then, a parameter inversion model is constructed to calibrate the model parameters. By comparing the revised model drawdown and the theoretical drawdown of the classical model with the measured drawdown, it verifies the rationality of the well revised model proposed in this paper. Then, the variation characteristics of the air entry plane elevation under the modified well model are discussed by using parameter sensitivity analysis. Finally, the computational method and variation characteristics of seepage velocity in the vertical direction of the air entry plane are discussed. It is found that the drawdown curve obtained by the revised model coincides with the measured drawdown curve; The air entry plane elevation increases with increasing distance from the center of the well and the specific yield and decreases with increasing pumping flow rate. In the early stage of pumping, the air entry plane elevation decreases with increasing hydraulic conductivity, but the opposite is true in the late stage of pumping. The calculation results of the analytical expressions of the seepage velocity in the vertical direction based on the water balance relation at the air entry plane (based on the linearized or non-linearized equation, using complete solutionor approximate solution) and based on continuity equation of seepage flow at the air entry plane (based on the linearized equation, using complete solution) under five conditions are basically consisent, and the trends of the curve are consistent with each other, showing a nonlinear increase with the prolongation of pumping time.

 The disturbance signals generated by ferromagnetic objects in a magnetic field provide a non-contact and passive means for target localization and tracking. However, traditional magnetic vector localization methods based on physical modeling suffer from degraded accuracy and limited robustness in complex environments. In this paper, we propose a magnetic anomaly tracking convolutional neural network (MagTrack-CNN) for high-precision spatial dynamic localization of ferromagnetic objects. The proposed method employs a dual-layer magnetic vector observation architecture to enhance localization sensitivity along the depth direction by incorporating vertical gradient information. A dual-branch independent prediction network is designed to mitigate gradient competition among spatial components, while a multi-scale feature extraction framework is constructed to effectively capture magnetic anomaly patterns at different spatial scales. Experimental results in stable magnetic field regions for localization scenarios involving a single uniformly magnetized target demonstrate that MagTrack-CNN achieves an overall positioning accuracy of 1.98 cm on the test set, and exhibits superior accuracy in z-axis localization. In dynamic localization tests across different trajectory types, the method consistently produces correct dynamic positioning. Meanwhile, noise sensitivity experiments show that under measurement noise levels of 0.5%-3.0%, the model maintains low errors (the mean absolute error  increases from 0.42 cm to 0.46 cm). Furthermore, the per-sample inference time remains within 2.3 ms, highlighting its promising potential for practical applications.

To enhance the economic efficiency of engineering geological investigations for construction projects and accurately reveal the correlations between the physical and mechanical parameters of cohesive soils, in this study taking the cohesive soils in central urban area of Changchun as the research object, based on the data from 1 092 physical tests, compression tests and direct shear tests, two multiple regression models were constructed to emphatically analyze the rationality of the model’s premise assumptions and the interaction effects among explanatory variables. The results show that: 1) The residual probability density plot and residual normal Q-Q （quantile-quantile） plot confirm that the model error terms follow a normal distribution, with homogeneous and mutually independent variances, satisfying the basic assumptions of the multiple regression model. 2) The two-factor interaction effect plots and Johnson-Neyman plots indicate significant interaction effects among water content, density, void ratio and liquidity index. A regression model considering interaction effects can more accurately predict the compression coefficient. It is feasible to use multiple linear regression to analyze the correlations between physical and mechanical parameters of cohesive soils.

 Adjusting the derivative order of fractional-order magnetic gradient (FMG) can tune the resolution of magnetic materials at different depths. However, direct FMG measurement methods remain lacking. Therefore, this article focuses on the research of fractional-order magnetic gradient measurement method. This article uses the external source terms of the Laplace equation solved in a spherical coordinate system as the model of the magnetic field inside the sphere, calculates the fractional-order derivatives in the corresponding directions of the model, and achieves FMG measurement. We evaluate sensitivity to measurement position error and field-measurement error through simulation, showing that the normalized root mean square error  increases monotonically with the derivative order. An experiment is conducted to verify the measurement method, and the relative error between the experimental results and the theoretical values does not exceed 6.00%, verifying the correctness of the measurement method.

The Tugurige gold deposit is a large-scale gold deposit which is located in the Xing’an-Mongolia Orgenic Belt(XMOB). In order to investigate the source of its ore-forming fluids, a systematic study of the carbon and oxygen isotopes of the deposit was conducted. Results show that the average carbon isotope δ13CV-PDB value of the green calcite is -8.85‰, while the average oxygen isotope δ18OV-SMOW value is 11.65‰. The trends in δ13C and δ18O reflect a transformation of calcite from low to high enrichment levels, indicating two distinct mineralization stages. On the basis of previous research, this study proposes that the origin and composition of ore-forming fluids differ across these stages of mineral deposit formation: In the stage Ⅱ, the ore-forming fluids mainly originated from deep-seated magmatic water, whereas in the stage Ⅲ, seawater-derived carbonates were mixed. Comparing the C-O isotope compositions between the Baoyintu Group and regional formations revealed significantly depleted oxygen isotopes, indicating water-rock interactions during the ore-forming process. Simulations of water-rock reactions indicate that soluble carbon in the ore-forming fluids mainly existed in the form of HCO3-. The simultaneous δ13C and δ18O values of the ore-forming fluid, -9.2‰ and 8‰ respectively, imply that the initial fluid originated from magma and subsequently interacted with marine carbonate rocks in the surrounding rocks during the evolution process. Comprehensive research on the Tugurige gold deposit highlights it typical characteristics of a magmatic hydrothermal gold deposit, with geological features, mineral symbiosis, and fluid characteristics all indicating a close relationship with magmatic hydrothermal activity.

The Fengning Xingyuan superlarge fluorite deposit in Hebei Province is located in the western section of the north Hebei-west Liaoning fluorite metallogenic belt. While previous studies have established fundamental geological characteristics of the deposit, but the formation age, metallogenic dynamics background, material sources and genetic classification of the deposit are still unclear. This study integrates zircon U-Pb dating, rock geochemical analysis and Sr-Nd isotope studies of the mineralised granite porphyry, building upon comprehensive field investigations. The results show that fluorite mineralization occurs within granite porphyry veins and their hanging wall/footwall of fracture zones, exhibiting vein, reticulate-vein, breccia, and banded structures, and accompanied by pervasive silicification and sericitization of surrounding rocks. Zircon U-Pb dating yields an Early Cretaceous age (（137.9±3.4） Ma) for the granite porphyry, which displays distinctive geochemical features of high silica (w(Si2O)=72.48%-75.70%), high alkalinity (w(Na2O+K2O)=5.28%-10.23%), calcium-poor (w(CaO)=0.35%-2.52%), magnesium (w(MgO)=0.10%-1.47%), belonging to the peraluminous, calcium alkali-potassium basalt series. The trace element spider diagrams show enrichment in Rb, Th and Zr but depletion in Sr, Ba, Nb and Ta, and the relative enrichment of light rare earth elements and the strong Eu-negative anomalies, toghther indicating A-type granite characteristics. Integrated with regional tectonic evolution, these features suggest the granite formed during large-scale extension and thinning of the North China craton. The Sr-Nd isotopes show that the granite porphyry likely originated through partial melting of crustal source materials. The geological and geochemical characteristics of the deposit suggest that the Ca in the mineralizing fluids originates from the hydro-rock interaction between the hydrothermal fluid and the volcanic host rocks/Ca-rich strata, while the F derives principally from the magma, and the deposit constitutes a medium-low-temperature magmatic-hydrothermal fluorite deposit genetically related to the granite porphyry.

 Most seismic data processing techniques have been designed to solve specific practical geophysical problems, with limited focus on the fundamental properties of seismic data. Seismic data vary simultaneously in time, space, and frequency, making conventional signal classification methods inadequate. Currently, there is no clear definition of the essential attributes of seismic data, which limits the development of advanced processing techniques. Here, we propose a new definition of nonstationarity tailored to seismic data, based on the unique ordering relationships of data in seismic acquisition systems and the presence of practical nondeterministic factors. Under this framework, we identify six representative nonstationary features, including statistical properties of random seismic noise, and amplitude compression, energy spectrum predictability, time-frequency spectral attenuation, waveform similarity and amplitude periodicity of effective signals. To address these features, we review the recent advances in seven corresponding processing strategies, including median filtering, sparse transformation, predictive filtering, time-frequency analysis, inverse Q-filtering with Q (quality factor) estimation, similarity analysis, and chaotic system modeling. These methods support the emerging of “two-wide and one-high” integrated acquisition schemes for massive datasets collected in “three-complex” environments—complex near-surface conditions, structural complexity, and heterogeneous lithologies—and target the “three-high and one-fast” processing goals: high signal-to-noise ratio, high resolution, high fidelity, and fast computation. This work lays the theoretical and technical groundwork for high-precision seismic exploration.

The Cenozoic basalts in Fujian are widely developed and contain abundant mantle xenoliths, whose mineralogical characteristic provide insights into the properties of lithospheric mantle. This study conducted electron microprobes, clinopyroxene LA-ICP-MS trace element, and in-situ Sr isotopes analyses on the minerals in Cenozoic basalts and peridotite xenoliths from Xiamen along the Fujian coast, as well as Mingxi and Minqing in the inland region. The results indicate that the clinopyroxenes in both basalt and peridotite xenoliths are predominantly diopside. The peridotite xenoliths are divided into two groups based on mineralogical characteristics: Group A (Mg# > 90), representing an ancient, refractory lithospheric mantle, and Group B (Mg# < 90), representing a younger, modified enriched lithospheric mantle. Group A clinopyroxene exhibit slight negative anomalies in high-field strength elements Nb and Ti, and strong negative anomalies in Hf, Zr, and Ta. In Group B peridotite, clinopyroxene shows differences, with slightly negative anomaly in high high-field strength elements Zr and Hf and a pronounced negative anomaly in the large ion lithophile element Ba. The clinopyroxene in both the phenocrysts and matrix of the basalt exhibits LREE enrichment and HREE depletion, with the rims showing greater depletions in high-field strength elements Th and Nb compared to the cores, along with enrichments in large ion lithophile elements Sr and Eu. Most clinopyroxenes in both Group A and Group B xenoliths have experienced silicate melt metasomatism, while a few Group A clinopyroxene suggest a mix between silicate and carbonate melt metasomatism. In-situ Sr isotope ratios for clinopyroxene range from 0.702 57 to 0.703 67, with most rims showing higher 87Sr/86Sr ratios than the cores, like due to interaction with materials of higher 87Sr/86Sr ratios. The Fujian peridotite probably represents a newly modified lithospheric mantle of the Pacific plate subduction asthenosphere mantle, following decompression ascent.

Addressing the complex engineering challenges of a excavated metro station in Chengdu that partially traverses existing buildings, this study adopted a localized undercut and expansion excavation strategy through comprehensive comparative analysis and finite element simulation. The research proposed a scientific method for determining the boundary between open and undercut excavation, and delved into various aspects of key construction technologies such as settlement control, primary support for undercut excavation, and secondary lining, including pre-construction dewatering, ground surface grouting reinforcement, and numerical simulation analysis, as well as advanced support during construction, excavation sequence control, and secondary lining structure construction. The research results indicate that, compared to the traditional open-cut method, the undercut and expansion excavation technique can significantly reduce demolition difficulties, It has significantly cut the investment in project costs by approximately 104 million yuan and shortened the construction period by two months. The key to successful construction lies in accurately determining the boundary between open and undercut excavation, which is recommended to be set outside the structural haunch and 3 m away from the building foundation. Meanwhile, combining sleeve valve pipe ground surface grouting with tube well dewatering measures can effectively control ground surface settlement. During construction, it is necessary to flexibly select construction methods based on the span of the undercut tunnel and the characteristics of surrounding rocks, properly handle the nodes of the primary support structure, ensure effective connection between secondary lining construction and the removal of the primary support structure, and attach great importance to the application of construction monitoring.

 During the Indosinian period, small granitic bodies or stocks were wildly developed in the Songpan-Garze orogenic belt. This study focuses on the granitic body in Qiuzhi area of Qinghai Province, located along the southern margin of Songpan-Garze orogenic belt. The petrogenesis and tectonic setting of the granitic body are discussed through petrography, zircon U-Pb chronology, zircon Lu-Hf isotope, Sr-Nd isotope of whole rock and whole rock geochemistry. The results show that the granites in Qiuzhi area are mainly granodiorite, characterized by weak sodium enrichment (Na2O/K2O =0.97-1.34) and a low aluminum saturation index (A/CNK=0.99-1.08), thus classified as weak peraluminous calc-alkaline series granites. Rare earth element patterns show enrichment of light rare earth elements and depletion of heavy rare earth elements, along with a right-leaning distribution. The rocks are enriched in Rb, K,U, Th, La, Ce, Nd, Zr, Hf and Y, while being depleted in Ba, Sr ,Ta, Nb, P and Ti. The weighted average age of granodiorite zircon 206Pb/238U is (215.4±1.4) Ma (MSWD=1.05, n=23), indicating a Late Triassic diagenetic age. Zircon Hf isotopic values (176Hf/177Hf)i range from 0.282 377 to 0.282 437, with εHf(t) between -9.44 and -7.19, and two-stage model ages (TDM2) from 1 840 to 1 702 Ma. The initial Sr isotope values (87Sr/86Sr) i of whole rock range from 0.709 783 to 0.710 530, εNd(t) ranges from -8.2 to -7.8, and the two-stage model ages (TDM2) range from 1 659 to 1 630 Ma. These findings suggest that the magma source is the partial melting of the ancient crust material, exhibiting characteristics of calc-alkaline I type granite. By correlating regional geological data with the geochemical characteristics of the petrosphere, it is concluded that Qiuzhi granitic body is a product of lithospheric delamination, asthenosphere material upwelling, and lower crustal partial melting within the background of Late Triassic post-collision environment.

 Currently, the exploration potential for mineral resources in China’s plains and gently undulating hilly areas is relatively limited. Future prospective areas for mineral exploration are mainly distributed in the deeply incised, high-altitude regions of western China. These areas are characterized by rugged topography, challenging accessibility, and sensitive ecosystems, which impose significant constraints on the implementation of traditional ground-based geophysical exploration methods. As an efficient geophysical detection technique, the time-domain airborne electromagnetic (TDEM) method holds great application value for mineral exploration in deeply incised complex terrain. This study conducts three-dimensional forward modeling research for TDEM surveys based on the finite volume method and octree mesh technology. The correctness of the forward algorithm is first verified using a half-space model. Ridge and valley terrain models are constructed to compare and analyze the differences in electromagnetic responses under different flight modes. Furthermore, by embedding low-resistivity anomalous bodies beneath undulating terrain, the coupling mechanism between topographic effects and ore body responses is investigated. Finally, the method is performed to forward modeling based on an actual geological profile from the Xiarihamu area. The research demonstrates that in areas with steep terrain such as ridges and valleys, the early-time responses are generally enhanced, while the late-time responses significantly decrease at ridge tops and increase markedly at valley bottoms, revealing characteristic terrain-induced distortions. Additionally, topography causes complex multi-faceted distortions in the responses of mineralized anomalous bodies: early-time and late-time responses may be obscured by terrain-induced distortions, but the variations caused by the anomalous bodies remain identifiable during the mid-time response stage. Lastly, the modeling results from the real geological profile verify the practicality of this method in deeply incised terrain and complex geological conditions, providing reliable theoretical support for three-dimensional inversion of TDEM data.

Deep dolomite has been a key focus of deep exploration in recent years, with dolomite cementation commonly found in its internal pores. However, there is relatively less research on the combination of dolomite cement grain occurrence and its effect on pores. Therefore, taking the Longwangmiao Formation of the Lower Cambrian in the Gaomo area of the Sichuan basin as an example, comprehensive data such as core samples, thin sections, cathodoluminescence, carbon-oxygen isotopes, and inclusions were used to study the types, characteristics, structures, volume fraction, and their effects on pores of dolomite cement. The crystals of dolomite cement mainly have shapes such as semi rhombus, rhombus, ring shaped, saddle shaped, etc., with particle sizes ranging from powder crystals to giant crystals. Cement crystals and pores form three types of structures: lining, bridging, and embedding. Using the frequency of development (the number of samples that develop a certain structure/the total number of samples of granular dolomite or grain dolomite) to characterize the degree of development of a certain structure, the embedding structure is the most developed in dolomite (48.3%-89.5%), followed by the bridging structure (22.4%-73.7%), and the lining structure is the weakest (8.6%-55.2%). The inner lining structure and bridging structure are mainly developed in granular dolomite, with volume fraction of 0 to 15% and 25% to 50%, respectively, and their development degree increases with the volume fraction of fine-grained dolomite cement. Embedding structures are commonly developed in dolomite, with a volume fraction mainly ranging from 50% to 100%, and their development is positively correlated with the volume fraction of medium crystalline to giant crystalline dolomite. The inner lining structure and bridging structure are mainly formed during the syndiagenetic stage to the middle diagenetic stage, while the embedding structure is mainly formed during the late diagenetic stage. The formation of inner lining and bridging structures earlier can reduce the damage to pores caused by solution compaction during diagenesis, while the embedding structure can damage residual pores. Based on the porosity of the layers with mainly developed embedding structures, the porosity of the layers with mainly developed inner lining and bridging structures can be increased by 50%.

As the oldest seamount and the biggest guyot found in the South China sea (SCS) central basin, Guanshi guyot is located on the 17°N fossil spreading center near the Manila trench. The dredged plagiogranite sample on Guanshi guyot shows trace element and isotopic composition similar to those of mid-oceanic ridge basalts (MORB), and its pyroxene and whole-rock 40Ar/39Ar dating yields ages of (32.3±0.5) Ma and (28.9±1.9) Ma, which is inconsistent with popular research acquired from marine magnetic anomalies identifying (~23.6 Ma). So further study is required to inspect the opening history of SCS central basin. The density of the dredged plagiogranite sample is measured for many times, which ranges from 2.757 3 to 2.941 6 g/cm3, and the median density is 2.846 5 g/cm3. The stratum velocity field originated from multi-channel seismic (MCS) data is used to transform the time-domain MCS interpreting data into the depth-domain. By creating many crust density models across Guanshi guyot with constraint of the depth-domain sediment basement and gravity anomalies, we infer that the most possible internal density of Guanshi guyot  mainly ranges from 2.70 to 2.75 g/cm3, higher than the average density of younger seamounts with SCS central basin (2.60-2.70 g/cm3), and lower than the average density of gabbro from lower oceanic crust (2.80-2.90 g/cm3). To be precise, higher density (>2.80 g/cm3) rock which can be drilled in the local area in the southern part of Guanshi guyot can’t be excluded in this study. Comprehensive considering the crust density models across Guanshi guyot, MCS interpreting data, and life cycle of seamount, we infer that Guanshi guyot is an intraplate seamount (or oceanic island) during the seafloor spreading period of SCS central basin. Further studies have to be done to understand the relationship between dredged plagiogranite sample and Guanshi guyot. For better understanding the origin of the plagiogranite during the evolution of intraplate seamount, a more reasonable tectonic model should be explored.

 The microtremor horizontal-to-vertical spectral ratio (HVSR) method is an efficient and non-invasive geophysical technique widely used in urban geological surveys and engineering investigations. However, transient interferences caused by pedestrians and vehicles can distort the shapes of HVSR curves. Existing transient interference elimination methods have limitations: the STA/LTA (short-term-average over long-term-average) method is prone to misjudgment and requires complex parameter tuning; The manual rejection method is inefficient; And the frequency-window based rejection algorithm considers only peak-frequency information. To address these issues, this study proposes a machine-learning-based interference suppression method for microtremor HVSR data. First, curve-shape features are extracted to train a curve-rejection model for identifying and removing HVSR curves that significantly deviate from the mean trend. Then, peak-related features are extracted to train a peak-identification model for recognizing valid resonance peaks within the  curves. Finally, a density-based spatial clustering of applications with noise (DBSCAN) algorithm is applied to cluster and further eliminate curves containing peaks with abnormal frequencies or amplitudes. The curve-rejection and peak-identification models achieve F1 scores of 0.967 and 0.985 on the test set, respectively, demonstrating excellent classification performance. Case studies show that the proposed method exhibits higher stability and accuracy in eliminating abnormal curves than the STA/LTA and frequency-window based rejection methods. The processed HVSR curves display more concentrated spectral distributions, more convergent standard-deviation curves, and clearer, more stable peaks. Moreover, the proposed method achieves efficient automatic processing while maintaining strong consistency with manual rejection results.

Great Xing’an Range is located in the eastern part of the Central Asian orogenic belt. It is a composite part of the Paleo Asian Ocean, circum Pacific Ocean and Mongolia Okhotsk Ocean. Having strong tectonic magmatic activity, it is the best window to study the Mesozoic tectonic magmatic evolution in Northeast China. The authors studied the Jurassic granitoids in the Jinjianggou of Central Great Xing’an Range, and performed systematic analyses of zircon U-Pb chronology and whole-rock elemental geochemistry. The zircon U-Pb age data indicate that petrogenic ages of medium-fine grained granodiorite is (165±1)Ma, the diagenetic ages belong to Middle Jurassic, the petrogenic ages of medium-fine grained syenogranite and medium-coarse grained monzogranite are (152±1)Ma, (147±1)Ma and (148±1)Ma, with their diagenetic ages belong to Late Jurassic. Geochemical data show that the granodiorite and monzogranite samples have low silicon, and are poor in magnesium, iron and titanium, TFeO/MgO ratio and Zr/Hf ratio; They are enriched in Th, Rb, U, Ce, La, Hf and poor in Sr、Nb、Ba、Ti、P, and have geochemical characteristics of type I granite. The magma was originated from the source area of partial melting of igneous material in the lower crust. The syenogranite samples are enriched in silicon, high in potassium, poor in magnesium, iron and titanium, low in TFeO/MgO ratio and Zr/Hf ratio, relatively high in differentiation index, strong europium negative anomaly, relatively rich in Th, Rb, U, Hf, Ce, La, Nd elements, and deficient in Sr, Nb, Ba, Ti, P and other elements, and has geochemical characteristics belonging to highly differentiated type I granite. The magma was originated from the source area of partial melting of igneous material in the lower crust. Combined with the chronology and geochemical characteristics, the medium-fine grained granodiorite was formed in the syn-collision tectonic setting, and medium-fine grained syenogranite and medium-coarse grained monzogranite were formed in post-orogenic extensional tectonic environment, which were related to the scissor closure of the Mongol-Okhotsk Ocean from west to east. We believe that the final closing time of the western section of the Mongol-Okhotz suture zone is the Late Middle Jurassic.

Rock thermal physical properties are key parameters in the fields of geothermal, engineering geology, and oil and gas geology. In order to have a clear understanding of the influence of factors such as pore fluid medium and saturation on the thermal conductivity of clastic rocks, in this study, typical clastic rock samples from the Cenozoic of  Qaidam basin were selected, and their thermal conductivities were measured by applying the unsteady state method. The thermal conductivity of clastic rocks decreases with the increase of porosity, and the decrease of thermal conductivity can be up to 37.6% in the samples of dense reservoirs with porosity lower than 5.0%. The thermal conductivity of  clastic rocks showes a significant positive correlation with the saturation degree, and the effect of water saturation on  transverse and longitudinal thermal conductivity is more significant than that of oil saturation. The ranges of thermal conductivity anisotropy coefficients of clastic rocks in dry state and in water-saturated state are 0.648-1.546 and 0.840-1.200, respectively, indicating that the saturation degree has an attenuating effect on the anisotropy of thermal conductivity. The greater effect of quartz content on the thermal conductivity of the rocks and the brittleness of the quartz-rich clastic rocks result in more developed microfractures in the rock samples, whereas microfractures in situ formation are usually saturated with pore fluids, it is hypothesized that the development of fractures negatively affects the actual stratigraphic thermal conductivity and its anisotropy in dry conditions, but under water-bearing conditions, groundwater convection along the microfractures significantly increases the thermal conductivity.

 The petrogenetic age and magmatic evolution of large granitic complexes are significant for elucidating petrogenesis and deep-seated dynamic processes. The Huangyangshan pluton in eastern Junggar, Xinjiang Province, a typical granitic complex within the Kalamaili alkali-rich intrusion belt, is featured by accompanying alkaline and aluminous A-type granites and hosting two large crystalline graphite deposit closely associated in its aluminous unit. However, the petrogenetic sequence of its lithofacies and the relationship between magmatic evolution and graphite mineralization remain debated. Based on detailed field geological investigations and previous data, this study conducted SIMS zircon U-Pb dating analyses on different lithofacies of the Huangyangshan pluton, and discussed its evolution sequence, the relationship between magmatic evolution and graphite deposit formation. The results reveal reveal a clear south-to-north progression: Fine-grained biotite alkali-feldspar granite ((312.7±1.4)Ma), medium-coarse-grained biotite alkali-feldspar granite ((313.5±1.5) Ma), medium-fine-grained amphibole alkali-feldspar granite ((302.4±1.9)Ma), medium-grained arfvedsonite granite ((297.7±1.5)Ma), and medium-fine-grained arfvedsonite granite ((297.1±1.5)Ma), all formed in the Late Carboniferous, showing a clear magmatic evolution sequence from early to late stages. The ~15 Ma duration of aluminous A-type magmatism likely controlled the super-large graphite deposit formation within the pluton. The formation of the Huangyangshan pluton initially involved dehydration melting of biotite and amphibole in calc-alkaline rocks in the magma source area to generate the aluminous A-type unit. Subsequent partial melting of hornblende (+ minor biotite) in the pre-existing calc-alkaline rocks, induced by mantle-derived high-temperature magma or alkali-rich fluid metasomatism, ultimately formed the alkaline A-type unit in the northern part of the pluton.

Deep learning-based methods for multiple attenuation have been a pivotal research focus in the field of seismic data processing. Traditional supervised neural networks are data-driven and rely on direct end-to-end mapping. The physical interpretability of the network model outputs is limited, and the effectiveness of multiple attenuation is constrained by the quality of labeled seismic data. This paper proposes an improved deep learning method that integrates the time-spatial physical information of 3D seismic data volume as prior knowledge with the neural network output to construct an implicit polynomial of multiple and full-wavefield. In this approach, the output of the neural network is not labeled seismic data but coefficients of polynomial function space. By incorporating prior knowledge into the loss function and minimizing this loss function, an implicit polynomial of multiple and full-wavefield is derived. This approach obviates the matching subtraction process in surface-related multiple attenuation. The results of synthetic and field data demonstrate that the proposed method surpasses traditional end-to-end deep learning methods in terms of efficacy and accuracy in free surface-related multiple attenuation.

The gold bearing granite porphyry in Xiacaodi Village, Jiuzhaigou County is located in the western extension of  Yangshan gold deposit belt in the West Qinling. In order to explore the relationship between magmatic activity and gold mineralization in this metallogenic extension zone, as well as characterize the parent rock of the ore bearing granite porphyry, petrographic, geochemical, and LA–ICP–MS zircon U–Pb dating studies were conducted on the gold bearing granite porphyry. The results indicate that the granite porphyry belongs to the calcium alkaline series, characterized by rich silicon aluminum and poor iron magnesium calcium; The trace elements are characterized by enrichment of K, Rb, Cs, U, Pb, while the mass fractions of Nb, Ta, Zr, Hf, Ti and other elements are low, while Ba, Sr, Nb, Ti and other elements are deficient. The δCe is 0.91 to 0.98, which is similar to the distribution pattern of volcanic arc granite, indicating genetic association with subduction collision environments; The total amount of rare earth elements is 74.78% to 90.28%, with characteristics of light rare earth element enrichment and heavy rare earth element depletion; The δEu value ranges from 0.62 to 0.79, indicating weak loss of europium and belonging to peraluminous granite. Zircon U-Pb dating yielded four distinct age populations: (217.7±2.2), (222.3±5.2), (216.5±5.5), and (758±11) Ma. Combined with previous comparative analysis of geochemical, isotopic, and other data from intermediate acidic intrusive rocks (veins) in  Yangshan gold belt, it is believed that the gold mineralization in  Yangshan gold belt is closely related to the Late Indosinian magmatic activity, and the granite originates from partial melting of the basement rocks (Bikou Group) in a collision environment. The granite porphyry in Xiacaodi Village is a typical post magmatic hydrothermal gold deposit type within  Yangshan gold belt. This type of granite porphyry rich in silicon and aluminum is a horizontal metallogenic indicator for gold prospecting, while vertically it may overlie gold-bearing bodies genetically related to early-stage intermediate-acidic veins in its lower part.

 In cold region engineering, the shear performance of frozen soil-structure interface is a key factor influencing the long-term service stability of facilities. However, the existing studies lack systematic characterization of the interface damage mechanism under the action of multi-physical field interactions. In order to reveal the mechanical behavior of frozen soil-structure interface by adjusting the ice-water phase transition process under the disturbance of thermodynamic conditions, this study systematically reviews the research progress of shear properties of frozen soil-structure interface from three aspects such as experimental methods, influencing factors and constitutive models. Firstly, by summarizing the methods of direct shear test, in-situ test and model pile test, the influence pathways of various factors on the mechanical behavior of the interface under the multi-field coupling condition of heat-water-salt-force are clarified. Furthermore, the mechanism of temperature, moisture, freeze-thaw cycle and salt on the interfacial shear performance by regulating the ice-water phase transition process was analyzed. Finally, the applicability and limitations of the existing constitutive model of frozen soil-structure interface are evaluated. The results show that the temperature gradient and water migration change the interfacial shear performance by regulating the ice cementation strength and the thickness of the unfrozen water film during the ice-water phase transition process. The pore reconstruction and ice crystal differentiation caused by freeze-thaw cycles lead to the deterioration of interface strength. Salt affects the interface space composition by changing the phase transition temperature threshold and salt crystallization expansion effect. The existing models have obvious deficiencies in ice-water phase transition, long-term freeze-thaw and multi-field coupling characterization. It is suggested that future work focus on developing a thermo-hyforr-salt-mechanical coupled interface model based on a “test-observation-model” framework integrated  with cross-scale observation technology, thereby providing a design basis and research direction for frost-heave prevention and disaster mitigation in cold regions.

The Tanchang-Yawan area in Gansu Province constitutes an important antimony mineralization area of the western Qinling metallogenic belt. This study presents a comprehensive geochemical investigation of silver (Ag), arsenic (As), gold (Au), bismuth (Bi), copper (Cu), mercury (Hg), manganese (Mn), molybdenum (Mo), lead (Pb), antimony (Sb), tin (Sn), and zinc (Zn) in stream sediments, coupled with systematic antimony prospecting prediction. Results show distinctive geochemical characteristics of antimony compared to other metal elements. Fundamental geochemical parameters including element concentration Clark value, global concentration coefficient (Kk), stacking intensity (D), and coefficient of variation (Cv) of Sb demonstrate significantly higher than those of other metal elements, reflecting the high enrichment of Sb, strong post-genetic superimposition, and highly uneven distribution. It has the highest value of mineralization index （β） for Sb, revealing the best ore-forming prospect among metal elements. The Triassic strata is considered as the main ore source beds of Sb, evidenced by average Sb concentrations（3.45-10.29）×10-6 exceeding crustal background levels by 17-40 times , with the Triassic Zhalishan Formation (T1z) and Guojiashan Formation (T2gj) representing optimal ore source beds of Sb. The spatial distributions of various element anomalies are cotrlled by  regional faults, generally. The locations of Sb mineralization is highly consistent with the its enrichment center, revealing that anomaly of Sb can directely indicate the ore-forming of itself. There is a strong correlation between the mineralization of Sb and anomalies of As, Au, and Hg, so that Sb-As-Au-Hg act as a combined prospecting geochemical indicator for antimony prospecting. According to the distributions of anomaly of antimony and indicator established in this study, 10 antimony perspecting target areas were divided into Tanchang-Yawan area, and 6 antimony mineralization points were newly found.

The main gas-bearing layer of Zhongmu sag has a relatively well-developed medium-small scale fractures. The complex geological structures in this area, coupled with the shielding effect of the coal seams, have led to both the resolution and the signal-to-noise ratio of the seismic exploration results being lower than the ideal values. The fracture parameters predicted by conventional methods are insufficient to characterize the development of local medium-small scale fractures. This has led to the need for a more suitable method. To address this issue, this paper refined and enhanced the 3D seismic data using maximum likelihood techniques to obtain the initial fracture orientation and fracture density. Based on the initial fracture orientation and density, the orientation guidance field was established, and a random discrete fracture network model was calculated through the orientation guidance field and fracture density. The random discrete fracture networks were connected to establish continuous random discrete fracture network models tailored to Zhongmu area, thereby reflecting the development patterns and distribution characteristics of medium-small scale fractures. And a comparative analysis was made between random discrete fracture network models and continuous random discrete fracture network models. It indicates that the threshold of the connected fracture distance has a significant impact on the modeling of random discrete fracture networks. The network of medium-small scale fractures in Zhongmu area is predominantly orientated in the direction of NEE, i.e., the azimuth of 60°-80°. The random discrete fracture network is coincided with the fractures in the layer. The orientation of the rose diagrams of the fractures located in the surrounding wells is well consistent with that of the fracture network model. The model yielded positive results in fracture prediction within the Lower Paleozoic fracture-developed zone of a pilot area in the south North China basin.

 To improve the quality of marine exploration signals, this paper investigates the stability control problem of a marine vibrator system with uncertain disturbances. Firstly, for the external and internal disturbances caused by the complex working environment in the ocean, an optimal fast finite-time extended state observer (FFTESO) is designed to observe the lumped disturbances of the system. Meanwhile, the observer can estimate the state variables of the system. Secondly, to improve the stability of the vibrator output waveform, a fractional-order finite-time sliding mode surface control scheme is designed to reduce displacement error and output chattering of the controller. Thirdly, the designed control system is proved to be fast finite-time stable via the Lyapunov’s integer and fractional order theorems. Finally, the simulation results verify the effectiveness and feasibility of the proposed control system combining a FFTESO with a fractional order finite time sliding mode control (FOFTSMC). The results show that the maximum relative error of the observer is reduced by 29.5%, and the peak-to-peak chattering value of the controller decreased by 25%.

The Gaojiadian pluton, located in the eastern Hebei Province on the northern margin of the North China craton, is a composite batholith that intruded during the early Yanshan period. It primary rock types include diorite, syenite, granite, with transitional varieties present. The pluton hosts hydrothermal vein-type gold deposits, primarily found in granite and diorite.To accurately determine the invasion period of the Gaojiadian pluton, four rock samples were analyzed by zircon chronology and trace element characteristics using LA-ICP-MS zircon U-Pb dating. The results indicate crystallization age of (197.4±1.9) Ma for quartz syenite, (176.7±1.2) Ma for fleshy-red biotite monzonitic granite, (175.8±1.7) Ma for gray-white biotite monzonitic granite, and (175.3±1.9) Ma for diorite-porphyrite, suggesting an intrusion age from the Early to Middle Jurassic. Dark diorite enclaves within the granite imply a mixed crust-mantle origin formed in an extensional tectonic setting. Zircon trace elements of all samples exhibit a left-leaning rare earth partitioning pattern with strong Ce positive anomalies and varying degrees of Eu negative anomalies. The zircon saturation temperature ranges from 682 to 824 ℃, representing the initial magma formation temperature. The magma exhibited a gradual cooling trend over evolutionary time and shares a similar partitioning pattern and crystallization temperature range with regional magmatic zircons. The high Ce4+/Ce3+ values of zircon represent relatively high oxygen fugacity, revealing the stronger mineralization potential of the Gaojiadian pluton, especially in the biotite monzonitic granite.

To simulate hydraulic fracturing and heat injection and extraction effect in hot dry rock reservoir, we established a  thermo-hydro-mechanical  coupling hydraulic fracture propagation and heat transfer model for simulating the complex fracturing fracture morphology of dry hot rock and conducting injection-production thermal analysis. Taking the hot dry rock（HDR） in Qinghai Gonghe basin as a reference, we constructed two case considered the geo-mechanical parameter characteristics and simulated the multi-well fracturing and heat recovery process, the numerical results of fracturing and heat injection and recovery show that: In HDR, the fracture initiation is influenced by the non-uniform stress field, exhibiting volumetric fracture characteristics. Fractures created through multi-well fracturing connect via natural fractures, providing over 95% of the heat exchange flow channels for heat injection and production. During heat injection and production, fluid mainly flows along the connected fractures, forming dominant heat exchange channels. This leads to a significant decrease in outlet temperature during the initial stage of heat injection and production, with the outlet water temperature dropping by 30-50 ℃ within the first three years, followed by a gradual slowdown in the later stages. Enhanced fracture complexity can increase effective heat transfer area, while optimized well placement and injection-production parameters improve thermal efficiency, enabling sustainable geothermal energy exploitation.

Forest ecosystems play an irreplaceable role in terrestrial ecosystems. The cross-border forests among China, North Korea, and Russia have abundant forest resources, providing wide habitats for numerous wildlife and plants. Scientific evaluation of forest health not only helps to protect and manage natural resources, but also effectively maintains biodiversity and promotes regional sustainable development. This article takes the border area among  China, North Korea, and Russia as the object, uses subjective and objective weighting methods to determine the initial weights of each evaluation indicator, and uses game theory to combine and optimize the weights. After determining the weights, based on the principle of extension, a matter-element extension model is constructed to evaluate the long-term forest health status. This research has shown that: 1) The weight allocation optimized through game theory shows that the vitality indicator dominates the four major categories of indicators in the indicator system, with a weight of 51.85%. This highlights the importance of vitality in forest health assessment, followed by indicators of system resilience (18.16%), site condition (16.43%), and soil quality (13.56%). 2) The results of the three periods in 2000, 2010, and 2020 show that the forest in the research area has the highest proportion of moderate health status, followed by good health status, and the lowest proportion of unhealthy status, with 16.50%, 15.53%, and 15.42%, respectively, showing a downward trend. This reflects that although some areas are in an unhealthy state, the forest health status is developing towards a better direction. 3) For many years, the multi-temporal and spatial characteristics of forest health in the research area have been dominated by a moderate health steady state, reflecting the stability of forest health. However, there are significant regional differences. In some regions of China, fluctuations coexist with high-quality steady states. While in North Korea, low steady states dominate but show signs of improvement. The health status of the western and eastern regions of Russia is diverse.

The U-Net encoder-decoder network structure is used to partition most buildings in mining areas, but the encoder-decoder structure does not make full use of the semantic and spatial features, resulting in low segmentation accuracy. Aiming at the defects of existing building extraction methods, a semantic spatial consistency semantic segmentation network (SSC-SeNet) is proposed. Firstly, the network uses a multi-channel structure to extract and integrate semantic features, spatial features, and consistency features. Secondly, a space extraction channel is introduced in the first three coordinate convolution of the main channel, and a Gabor Fourier filter is designed for further extraction of spatial features. Then, a semantic extraction channel is introduced at each layer of conventional convolution blocks in the main channel to improve the capability of semantic feature extraction. Finally, the feature fusion module is used to fuse the features of spatial extraction channel, semantic extraction channel and main channel, and the final segmentation image is generated. Experiments on the building data set of Xiangtan manganese mine with a resolution of 0.03 m show that the crossover ratio of SSC-SeNet is as high as 88.47% and the overall accuracy is 97.09%, both of which are ahead of mainstream traditional networks such as U-Net, and overfitting problems are overcome due to its lightweight characteristics.

In order to find selenium rich soil quickly, efficiently and accurately using selenium free data, it is necessary to build the best model to predict selenium rich soil. 502 data sets were selected from 1 277 1∶50 000 surface soil geochemical data. With w(Zn),w(K2O),w(P),w(Mo),w(Mn),w(Cr),pH,D（Devonian） as independent variables and Se rich or not as dependent variables, SPSS Modeler 18 software was used to build binary Logistic regression model, multi-layer perceptron neural network model, random forest model and support vector machine model (linear, multinomial, radial basis function, Sigmoid) for predicting Se rich soil, and the measured data of 35 soil samples were used for verification. The results show that, using binary Logistic regression model, multilayer perceptron neural network model, random forest model and support vector machine model (linear, polynomial, radial basis function, Sigmoid), the overall accuracy of prediction and verification of the seven prediction models and were 88.8% and 94.3%, 91.0% and 97.1%, 96.6% and 97.1%, 87.9% and 97.1%, 86.1% and 94.3%, 86.9% and 94.3%, 80.3% and 91.4%. The AUC were 0.948, 0.950, 0.993, 0.937, 0.945, 0.928 and 0.873, respectively. The accuracy and stability of the random forest model are the best. Meanwhile, this study identified clean selenium-rich soil and green selenium-rich mountain rice, indicating that this method is feasible in the prediction of selenium-rich soil, and it can be further extended to geological prospecting and environmental monitoring.

 To address the theoretical and technological bottlenecks in drilling and extraction under complex utilization, and to enhance China’s competitiveness in fields such as strategic resource development, new energy and extreme environment exploration, this study defines the concept of complex conditions, and separates it into four dimensions, namely, complex geological conditions, complex surface environments, complex resource resource conditions, and complex environmental protection requirements. It systematically reviews core literature, typical engineering practice cases, and achievements in key technological breakthroughs in the field of drilling and extraction under complex conditions at home and abroad. From five perspectives such as deep drilling technology and equipment, polar scientific drilling technology, unconventional energy and mineral drilling and extraction technology, bionic drilling and extraction theory and technology, and multi-process percussion-rotary drilling technology, the study conducts an in-depth analysis of the technological bottlenecks in this field. Aligning with major national strategic demands in the deep earth, deep sea, deep space, and polar regions, breakthrough pathways are proposed to shift from “passive response to complexity” to “proactive mastery of extremes”, based on four dimensions of deep earth extreme geology, cross-border extreme environments, low-quality and hard-to-extract resources, and stringent environmental constraints. This research provides a systematic technological framework and decision-making support for safeguarding national resource security, facilitating the transformation and upgrading of the energy structure, and implementing the strategy of building China into a leading science and technology nation.

Plane porosity is a key indicator for assessing the quality and resource potential of tight reservoirs. The current reservoir pore intelligent extraction and plane porosity calculation methods based on single image analysis technology have problems such as cumbersome pre-configuration, weak learning ability of sparse samples, and low accuracy of complex pore morphology recognition. For this reason, this paper proposes an intelligent calculation method of plane porosity in tight sandstone thin section by integrating SOLO (segmenting objects by locations) v2 algorithm and OpenCV (open source computer vision library) based on the idea of hybrid intelligence. Using the instance segmentation algorithm SOLOv2 to segment and label the pore regions in the image, and the distribution and percentage of pores are extracted in combination with OpenCV, then the plane porosity is calculated. Comparative experimental results show that this method is superior to the comparative algorithms such as YOLACT (you only look at coefficients), Mask R-CNN (mask region-based convolutional neural network) and SOLO in terms of Dice coefficient (0.88), pixel accuracy (0.91), and plane porosity calculation error (<0.1), with a faster execution speed.

 In Southwestern China, soil-rock mixtures characterized by loose structure, high porosity, and low strength are widely distributed. Tunneling through such strata often leads to, challenges such as poor stability, excavation collapse, and structural failure,posing serious risks to construction and operation. Based on a metro tunnel section in Chongqing, this study investigates the mechanical responses during tunnel excavation using physical model tests. It reveals the evolution of surrounding rock displacement, stress distribution, and surface settlement, and compares the effects of three excavation methods such as full-face, top-and-bottom heading, and core-soil-reserved methods. The displacement of the surrounding rock during excavation progresses through four stages, namely, undisturbed, slow deformation, abrupt change, and stable equilibrium. Deformation is most significant at the tunnel crown, where vertical displacement at 0.2 times the tunnel diameter above the crown is 1.96 times the horizontal displacement at the same distance from the haunch. Radial stress variations exhibit a zigzag trend. Stress-relief influence weakens from crown to shoulder to haunch, while stress-drop magnitude ranks shoulder, haunch, crown. Surface settlement also follows a four-stage pattern: insensitive, slow deformation, accelerated deformation, and stabilization. The curvature of surface monitoring points along the tunnel axis increases gradually as the excavation face approaches the monitoring section. The influence of different excavation methods on the disturbance of surrounding rock is decreased in the order of full section method, upper and lower bench method and reserved core soil method. The reserved core soil method can effectively reduce the deformation of surrounding rock, surface settlement and surface influence range.

 This review aims to elucidate the synergistic mechanisms, influential factors, and remediation potential of combined biochar-microbially induced carbonate precipitation (MICP) technology for addressing complex contamination in farmland soils. Recent studies were systematically analyzed to compare the physicochemical properties of biochar and the microbial mineralization pathways of MICP, assess their respective stabilization mechanisms for pollutants, and evaluate the performance and environmental implications of their combined application under different contamination scenarios. Biochar immobilizes pollutants via adsorption, complexation, and pH regulation, but its long-term stability is constrained by environmental aging. MICP achieves durable heavy-metal stabilization through carbonate precipitation and lattice incorporation, yet suffers from slow reaction rates and environmental sensitivity. Their combination produces notable synergistic effects: biochar serves as a microbial carrier and pollutant enrichment matrix to enhance urease activity and carbonate formation, while MICP-generated mineral layers reinforce biochar stability. The joint system reduces pollutant mobility and improves soil microbial diversity and enzymatic activity. However, issues such as ammonia accumulation, pore clogging, and uncertain long-term ecological impacts remain unresolved. The biochar-MICP combined approach integrates rapid adsorption with durable mineral stabilization, offering a promising strategy for farmland soil remediation. Future research should focus on microbial engineering, cost-effective calcium sources, targeted biochar modification, multi-process collaborative remediation systems, and long-term ecological risk assessment.

In recent years, the number of waste tires has continued to increase, and finding a reasonable way to dispose of waste tires has become an urgent problem. To find a way to deal with a large number of waste tires, this paper investigates the feasibility of using rubber fibers to improve expansive soil. Firstly, Direct shear tests were employed to investigate the effects of different rubber fiber contents on the mechanical characteristics of expansive soil. Then, a strength prediction model for rubber fiber reinforced expansive soil was developed based on the discrete model. The results shows that there is an enhancement in the strength of rubber fiber reinforced expansive soil with 5% and 10% fiber content compared to expansive soil, with the maximum strength enhancement at 10% rubber fiber content. Rubber fibers enhance the cohesion of expansive soil and have little effect on the internal friction angle. When the rubber fiber content is 15%, the rubber fibers adhere to each other and the fibers cannot be completely covered by the soil particles, which produces faults in the soil particles and thus reduces the soil strength. A strength prediction model for rubber fiber-reinforced expansive soil is proposed based on the discrete model, which effectively predicts the shear strength of rubber fiber-reinforced expansive soil.

In order to realize the fluoride solidification/stabilization of the lake and reservoir sediment, a compound of calcium hydroxide, potassium dihydrogen phosphate, iron sulfate and magnesium chloride was designed. Response surface methodology optimization experiments were conducted with the solidification/stabilization efficiency of fluorine-containing sediment as the dependent variable, and the calcium hydroxide addition, potassium dihydrogen phosphate addition, ferric sulfate and magnesium chloride addition as the independent variables. The results showed that the optimal solidification/stabilizing agent ratio was 3.572% calcium hydroxide, 4.342% potassium dihydrogen phosphate, 3.391% iron sulfate and 3.391% magnesium chloride. Using the optimal conditions simulated by the response surface method, experimental verification showed that the fluorine solidification/stabilization efficiency in the dredging sediment can reach 73.91%. The predicted value of 75.62% is in good agreement, indicating that the model is reliable and effective.

By using the large-scale model test system, the indoor model tests in the clay soil were carried out, and the macroscopic phenomena of the penetration characteristics of the static piles in the clay soil were obtained. In order to solve the problem of macro and meso mechanical response of the pile body during the pile driving process of the static pressure pile, the continuous penetration process of the static pressure pile was simulated by using two-dimensional particle flow numerical simulation software, and the variation law of the pile pressure force, the pile end resistance and the pile side friction resistance during the static pressure pile penetration process were studied at the fine level. The test results show that the mechanical characteristics of the static pressure pile are closely related to the diameter of the pile, the larger the pile diameter is, the greater the lateral extrusion pressure on the soil, the more obvious the lateral friction resistance of the pile, and the greater the pile compression force. With the increase of the depth of soil entry, the horizontal contact force chain of the soil at the position of the adjacent pile body increases, and the horizontal force chain closer to the pile end is larger, and the dense area of the contact force chain of the soil at the pile end shows a circle.

In order to investigate the beneficial effects of the combined drilling process of down-the-hole hammer and impact drilling, in this paper, the rock fragmentation process between rock and impact hammer head before and after the arrangement of small drill holes and under different hole diameters was investigated based on the HJC （Holmquist-Johnson-Concrete） constitutive model and the intrusion analysis method in the numerical simulation of LS-DYNA. At the same time, the rock fragmentation efficiency between the impact hammer drilling alone and the combined drilling process was quantitatively investigated in conjunction with the trial drilling test on site of the Jinyu Bridge in Quanzhou. The simulation results show that, with a constant number of small boreholes, as the diameter of the small boreholes drilled in the rock mass increases, the volume fraction of damaged rock mass increases. The increase in the diameter of the small boreholes reduces the energy required to break the unit volume of rock, which is beneficial for improving the fragmentation effect of the rock mass. The efficiency of energy transfer is related to the contact area between the impact hammer head and the rock. Under a constant number of small boreholes, an increase in the diameter of the small boreholes enhances the efficiency of energy transfer. However, beyond a certain value, an increase in the diameter of the small boreholes becomes unfavorable for the effective transfer of energy. During the process of the impact hammer impacting on the rock formation, the stress wave spreads out to the deeper part of the rock with time and gradually forms five  elongated fissures radiating from the center to the periphery. In addition, the results of on-site trial drilling tests show that the drilling efficiency of the combined drilling process can be improved by 54.47% on average compared with impact drilling alone. Comprehensive analysis shows that the implementation of the combined drilling process of down-the-hole hammer and impact drilling rig is conducive to improving the efficiency of rock crushing on site.

 The Songliao basin, a vital energy and industrial base in China, has substantial CO2 emissions and abundant underground saline water, possessing potential for CO2 geological sequestration. To enable the scientific selection of sites for CO2 geological storage in saline aquifer and to systematically evaluate the storage suitability of this region, this study focuses on the Central depression of Southern Songliao basin, analyzing the engineering geological conditions, sequestration potential, and socioeconomic conditions with a geographic information system (GIS) based multi-criteria decision analysis (MCDA) approach. Firstly, an evaluation indicator system comprising 3 primary indicators and 31 secondary indicators was established. Secondly, GIS was used to generate a 1 km-resolution raster layer of the data for each evaluation indicator. Then, reclassify the raster data according to the classification criteria. Finally, the raster layers for each indicator were overlaid with weighted values based on the weights determined by the analytic hierarchy process (AHP) and generate a  suitability map for CO2 geological storage in saline aquifers in the Central depression area of the southern Songliao basin. The results indicate that suitable areas are mainly located in the northern portion of the Honggang terrace and the southwestern part of the Changling depression, accounting for approximately 24.0% of the total regional area. Unsuitable areas are concentrated in the Fuxin uplift, accounting for only 6.8% of the total regional area. In total, nearly 56.0% of the area is suitable or relatively suitable for CO2 geological sequestration in saline aquifers. More than half of the areas within the Central depression in the southern Songliao basin meet the fundamental requirements for CO2 geological storage in saline aquifers. Further optimization and engineering deployment can proceed.

The production and living water of residents in Naozhou Island is mainly groundwater. In recent years, due to large-scale exploitation, groundwater in the region has been polluted to varying degrees. In order to explore the current situation of drinking groundwater source in Naozhou Island, this study comprehensively used mathematical statistics, piper three-line diagram, Gibbs diagram, ion ratio analysis and isotope analysis to study the water quality status, hydrochemical characteristics and genetic mechanism of 46 shallow groundwater points in Naozhou Island. The results show that the groundwater in the study area is generally neutral and weakly acidic. The cations of groundwater are mainly Na+ and Ca2+, and the anions are mainly HCO3- and Cl-. About a quarter of the points are saline water. The hydrochemical types are mainly mixed Cl-Ca·Mg type, Cl-Ca type and HCO3-Na·Ca type. The hydrochemical composition of shallow groundwater in the island is mainly affected by the combined effects of rock weathering and evaporation concentration, and some sites are affected by seawater intrusion.

 To construct a comprehensive anti-pollution system in mining areas, ensure the safety of soil and groundwater, and safeguard public health, it is of great scientific and practical value to investigate the release and migration patterns of heavy metals in mining areas and developing corresponding pollution assessment and numerical simulation methods. Based on sorting out existing research results, this review systematically summarizes the common experimental methods and kinetic models for studying heavy metal release from tailings and waste rocks, concludes the influence mechanisms of internal mineralogical characteristics and external environmental factors on heavy metal release behavior, and reveals the key roles of heavy metal occurrence forms, physical and chemical properties, and soil physical and chemical properties in their migration process. Meanwhile, this paper systematically reviews the common assessment methods and numerical simulation software currently used in the field of groundwater heavy metal pollution, conducts a comparative analysis of the applicable conditions and limitations of various methods and tools, and discusses the emerging application progress of machine learning technology in this field. Research shows that although existing achievements have made important progress in revealing the release and migration laws of heavy metals in the groundwater environment of mining areas and in pollution assessment and prediction, challenges still exist in comprehensively explaining the release and migration mechanisms under the coupling effect of multiple factors and realizing long-term dynamic and accurate prediction. Future studies should strengthen the combination of laboratory mechanism research and on-site monitoring, promote the in-depth integration of interdisciplinary collaboration and data-driven technologies, thereby providing more solid scientific basis and technical support for the prevention and control of heavy metal groundwater pollution and ecological environment protection in mining areas.

Selecting an appropriate method for assessing natural background levels (NBL) in groundwater is crucial for objectively understanding the NBL in groundwater. On the basis of reviewing the development process of NBL in groundwater, this article focused on summarizing the current methods for the assessment of NBL in groundwater with their advantages and disadvantages, and pointed out the development trend of the assessment for NBL in groundwater in the future. The methods for assessing NBL in groundwater can be roughly divided into five categories: Methods based on uncontaminated groundwater samples, pre-selection methods, statistics methods, exploratory data analysis methods based on graphs, and the combination of multi-methods. The method based on uncontaminated groundwater samples has been rarely adopted due to its inherent limitations. Pre-selection and statistics method are two commonly used independent methods in the study of groundwater NBL. Generally, the former one is more subjective than the latter one. Nowadays, the combination of multiple methods becomes a development trend in the research of groundwater NBL assessment, because some limitations of one method for assessing groundwater NBL may be avoided by the combination with another method. Among them, the combination of pre-selection and statistics methods is the most common way of combination. In addition, the combination of emerging exploratory data analysis methods based on graphs with pre-selection methods and/or statistics methods is commonly better than the combination of pre-selection and statistics methods. However, the use of the former combination often requires a good understanding of the hydrogeochemical characteristics in study areas. Therefore, the former ones for assessing groundwater NBL are less convenience and universality in comparison with the latter ones.

 Under low hydraulic gradients, low-permeability media often exhibit low-velocity flow. Investigating the mechanisms of low-velocity seepage is crucial for groundwater environmental protection research. Fluid flow in low-permeability porous media is influenced by a combination of multiple factors. This study systematically investigates the effects and mechanisms of low-velocity seepage in different types of cohesive soils at varying temperatures through laboratory constant-head permeability tests and nuclear magnetic resonance (NMR) experiments. The results indicate: 1) Temperature elevation significantly enhances the hydraulic conductivity of clayey soils. Within the 5-30 ℃ range, increasing temperature raised the hydraulic conductivity of white clay, loess, and silty clay by 289.9%, 210.4%, and 156.2%, respectively, while simultaneously decreasing the critical hydraulic gradient from approximately 10 to around 4. 2) Temperature elevation promotes the conversion of weakly bound water to free water. When temperature increased from 5 ℃ to 30 ℃, the bound water mass fraction of white clay, loess, and silty clay decreased by 23.1%, 22.8%, and 25.6%, respectively. Reduced bound water mass fraction increases effective pore space and lowers flow resistance, thereby enhancing hydraulic conductivity and decreasing the critical hydraulic gradient. 3) Temperature regulation of permeability coefficients exhibits a viscosity-bound water coupling effect, but bound water dominates permeability influence. Within the 5-30 ℃range, the contribution of bound water to hydraulic conductivity coefficients in cohesive soils increases with rising temperature. At constant temperatures, white clay soil exhibits the strongest influence of bound water on hydraulic conductivity, followed by loess, with silty clay showing the weakest effect.

Microwave heating technology as an alternative to conventional heating methods in oil shale exploitation microwave heating technology has gained significant attention as an alternative to traditional heating methods in the exploitation of oil shale reserves. In order to investigate the thermal response of oil shale under microwave radiation, as well as the changes in porosity, permeability, and internal displacement, numerical simulations were conducted using COMSOL Multiphysics software. These simulations were based on a coupled 3D electromagnetic-thermal-permeability-solid mechanics model. The results revealed the following key findings: Under microwave heating conditions, the temperature of the oil shale reservoir increases rapidly. Moreover, as the microwave power increases, the rate of temperature rise significantly accelerates. Different power levels result in distinct timeframes required for the reservoir to reach its pyrolysis temperature, with the fastest heating occurring at 800 W microwave power. With prolonged heating, porosity and permeability gradually increase, especially at higher power levels, where the growth is more pronounced. At the 500th day of microwave irradiation, the average permeability of oil shale reached its peak under different power levels, with a permeability of 1.93×10-16 m2 observed at 800 W. Microwave heating leads to the weakening of mechanical properties and increased formation damage in the reservoir. When the microwave radiation power reaches 800 W, the maximum displacement reaches 3.8 cm. In summary, selecting a microwave power of 600 W demonstrates significant engineering application benefits for the in-situ pyrolysis of oil shale reservoirs.

As a key region linking the West Pacific subduction system and the Central Asian orogenic belt, Northeast China witnessed a Mesozoic basins evolution closely related to multi-plate interactions. This study systematically investigates the geodynamic mechanisms of basin formation by analyzing tectonic-stratigraphic characteristics and lithospheric structures of NNE-trending Mesozoic sedimentary basins in Northeast China and adjacent areas, combined with both shallow processes and deep dynamic evolution of plate interactions. The results indicate that the Mesozoic basins in Northeast China exhibit a basin-and-range tectonic pattern, divided into western, central, and eastern basin groups, with a lithospheric structure thickening westward and thinning eastward. The basin evolution progressed through five stages: Early-Middle Triassic erosion and planation, Late Triassic-early Late Jurassic differential response to dual-sided subduction, Late Jurassic-early Early Cretaceous regional compression, middle-late Early Cretaceous extension dominance, and latest Early Cretaceous-Late Cretaceous alternating compression and extension. The superposition of two tectonic domains — the evolving subduction style of the Paleo-Pacific plate and the closure of the Mongol-Okhotsk Ocean—constitutes the core geodynamic control on basin evolution. Specifically, the regional extension triggered by the rollback of the Paleo-Pacific plate was the key driver for basin formation.

The Central Asian orogenic belt (CAOB), which experienced ~800 Ma of subduction–accretion associated with the Paleo-Asian Ocean, represents one of the largest and most complex accretionary orogenic systems on Earth. It records key geological processes, including oceanic subduction, crustal accretion, and subsequent tectonic overprinting, thus provides a crucial window for investigating Phanerozoic continental evolution within the Paleo-Asian Ocean tectonic domain. The Solonker suture, located in the south-central segment of the CAOB, records the evolution and final closure of this ocean and is widely regarded as its terminal suture. However, the eastward extension of this suture and the subduction polarity of the Paleo-Asian Ocean in this region remain subjects of significant debate. In recent years, two deep seismic reflection profiles of large dynamite shots have been developed across the Solonker suture, extending the detection depth to the lithospheric mantle and successfully revealing the seismic structural characteristics of fossil subduction zones beneath the suture. This study synthesizes and contrasts the seismic structures imaged by these two profiles and integrates them with newly acquired geophysical datasets to characterize the lithosphere-scale deformation architecture of the study area. The combined geological and geophysical evidence demonstrates that the Paleo-Asian Ocean underwent divergent double subduction in the south-central CAOB, culminating in its final closure along the Solonker–Tuquan between the Hegenshan and Xar-Moron sutures, with its eastern extension reaching into the central Songliao basin.

To reveal the subduction-accretion process of the Paleo-Pacific plate beneath the eastern margin of the Jiamusi block and to clarify the history of tectonic domain transition in Northeast China, this study focuses on reconstructing the subduction-accretion history of ancient oceanic plates. A comprehensive analysis was conducted on the material composition, accretion process, emplacement age, and tectonic setting of the Nadanhada terrane (Nadanhada accretionary complex belt) in Northeast China. The Nadanhada accretionary complex belt is divided into the Yuejinshan and Raohe accretionary complexes. The Yuejinshan accretionary complex is primarily composed of mafic-ultramafic rocks, siliceous rocks, marble, and metaclastic rocks. The mafic-ultramafic rocks formed between the Late Carboniferous and Late Triassic, wherein the protoliths of the metabasalt exhibit geochemical affinities of mid-ocean ridge basalt (MORB) and ocean island basalt (OIB), while the metagabbro originated in an active continental margin setting. The Yuejinshan accretionary complex records two major events: The subduction-accretion of the Panthalassa plate from the Late Carboniferous to Late Triassic, and the initiation of Paleo-Pacific plate subduction from the Late Triassic to Early Jurassic. Its emplacement age (Late Triassic to Early Jurassic) is broadly contemporaneous with the that of the Jilin-Heilongjiang high-pressure belt along the western margin of the Jiamusi block, collectively marking the initiation of the Paleo-Pacific domain in Northeast China. The Raohe accretionary complex constitutes an oceanic island assemblage, whose blocks include Carboniferous-Permian limestone, Middle Triassic-Middle Jurassic siliceous rocks and siliceous shale, Late Triassic-Middle Jurassic mafic-ultramafic rocks. The clastic matrix, which formed from the Middle Jurassic to Early Cretaceous, constrains the timing of accretion for the Raohe accretionary complex. The Raohe accretionary complex was emplaced along the eastern margin of the Yuejinshan accretionary complex in the Early Cretaceous. In summary, the formation of the Nadanhada accretionary complex belt completely records the continuous subduction-accretion history of the Panthalassa and Paleo-Pacific plates beneath the eastern margin of the Jiamusi block from the Late Carboniferous to the Early Cretaceous.

In order to unravel the spatiotemporal processes and dynamic mechanisms underlying Mesozoic multi-plate convergence in East Asia, this study focuses on the Mongol-Okhotsk tectonic domain—a critical region. By elucidating its Mesozoic tectonic evolutionary history as a vital component of the eastern segment of the Central Asian orogenic belt, this research seeks to provide constraints for reconstructing the interactions between regional plates. This study investigates the northern Heihe area of Northeast China through systematically integrating published zircon U-Pb chronology and whole-rock geochemical data of Mesozoic magmatic and sedimentary rocks, combined with detailed analysis of the sedimentary sequence in the Mohe basin, reconstructing the Late Mesozoic tectonic evolution history of this area. The present results show that the Mesozoic strata and magmatic activities in this area have comprehensively recorded the tectonic evolution process of the Mongol-Okhotsk tectonic domain from subduction, collision to post-collision extension. Zircon geochronology constrains the depositional age of the Emurhe Group in the Mohe basin to the Late Jurassic-Early Cretaceous (160-140 Ma), with the peak volcanic activity phase occurring at 125-110 Ma during the Early Cretaceou. Geochemical characteristics reveal a progressive transition of the magma sources from active continental margin arc settings to post-collisional extensional regimes. Quantitative crustal thickness reconstruction reveals an oscillatory “N” evolutionary trend (thickening-thinning-re-thickening), corresponding to three distinct geodynamic processes: subduction-related compression (~40 km), collision collapse (~35 km), and subsequent superimposed modification (~40 km). The Mongol-Okhotsk Ocean has undergone a temporally diachronous “scissor-like” closure process, with the middle section terminating during the late Middle Jurassic (~165 Ma) while the eastern section persisted until the early Early Cretaceous (~145 Ma). Following this collisional event, whole area transitioned into post-orogenic extension, subsequently overprinted by far-field effects of the Paleo-Pacific plate subduction. This study provides new evidence for understanding the ocean-continent transition process in the Mongol-Okhotsk tectonic domain and its mutual influence with the Paleo-Pacific tectonic domain.

To elucidate the mechanisms of reactive solute transport in heterogeneous rocks, it is essential to characterize their spatially heterogeneous structures. This study focuses on granite samples from Beishan in Gansu Province, China. Mineral composition segmentation is performed using both of the grayscale threshold segmentation and intelligent recognition method based on deep residual networks. Combined with geostatistical approaches, the semivariogram function is applied to establish the spatial correlation structures of sorption coefficients within the heterogeneous granite. The results indicate that the errors between the mineral segmentation results and the actual mineral components in the granite samples are less than 5%. Moreover, the intelligent recognition method can preserve the mineral continuity better. Among the major mineral components of the granite, the correlation lengths of the sorption coefficient for biotite are 3.75, 4.92, and 4.14 mm in the x, y, and z directions, while for feldspar they are 7.88, 6.15, and 5.94 mm, and for quartz, 5.25, 5.45, and 5.28 mm, respectively. These findings demonstrate that there is significant anisotropy in the granite's sorption properties.

The common reflection surface (CRS) stack imaging technique enhances the signal-to-noise ratio of seismic data by utilizing information from adjacent common midpoint gathers, making it a key technology for processing seismic data with low signal-to-noise ratios and low fold coverage. Whether using classical stepwise search or synchronous global search methods for CRS three-parameter optimization, a local optimization algorithm is ultimately required to enhance accuracy. The traditional Nelder-Mead simplex algorithm, with its simple search approach, suffers from relatively low computational efficiency. This paper adopts a derivative-free optimization algorithm called NEWUOA (new unconstrained optimization algorithm) as the precision enhancement method for CRS stacking. This algorithm dynamically constructs a quadratic interpolation model, employs a trust region iterative strategy, and utilizes curvature information of the objective function to improve computational efficiency. The algorithm was tested using a layered undulating model and the Marmousi2 model. The results show that for the simple layered undulating model and the complex Marmousi2 model, the NEWUOA generally outperformed or equaled the Nelder-Mead simplex algorithm in improving coherence values, with a computational efficiency increase of approximately 48% and 45%, respectively, compared to the Nelder-Mead simplex algorithm. This demonstrates that the NEWUOA can significantly enhance computational efficiency while maintaining the accuracy of CRS stack optimization, making it well-suited as a computational tool for precision refinement.

The Eastern Northern orogenic belt, located along the eastern margin of Eurasia, is composed of a series of microcontinents or terrenes, including, from west to east, the Erguna, Xing’an, Songliao, and Jiamusi-Khanka blocks. This belt preserves a complex Phanerozoic evolutionary history of multiple paleo-oceans, such as the Paleo-Asian, Heilongjiang, and Paleo-Pacific Oceans. However, the crustal evolution of these ocontinent microcontinents and their tectonic linkages to global supercontinent cycles remain relatively constrained, representing a key research frontier in modern geology. To address this, we first systematically compile published geochronological data from the Archean to Early Paleozoic to delineate the major evolutionary stages of the microcontinent group within the belt. We then integrate this temporal framework with the geochemical signatures of coeval magmatic records to evaluate the tectonic affinity of these microcontinents with ancient continental blocks throughout the supercontinent cycle since the Archean. Based on this integrated analysis, we propose a revised supercontinent evolutionary model for the microcontinent group. Our results indicate that the microcontinent group records five major geological events from the Archean to Early Paleozoic, which collectively define three distinct tectonic cycles.This history indicates their active involvement in the staged assembly and breakup of the Columbia, Rodinia, and Gondwana supercontinents. Furthermore, the tectonic evolution of the microcontinent group exhibits a persistent continental margin affinity, maintaining a close and dynamic tectonic relationship with the Tarim craton throughout these supercontinent cycles. During the Early Paleozoic, the microcontinent group in the Eastern North orogenic belt rifted from the northeastern margin of Gondwana and subsequently drifted northward to accrete to the southern margin of the Siberia craton. This migration established the fundamental regional tectonic framework that preconditioned the subsequent superimposition and transition of multiple paleo-oceanic systems along the eastern margin of Eurasia.

Superconducting magnetic measurement technology, especially the vector magnetic measurement system based on superconducting quantum interference device (SQUID), has extremely high magnetic sensitivity, broadband response, and excellent vector detection ability. The white noise of the superconducting magnetometer can reach 10 fT/Hz, and the noise of the full tensor gradiometer can reach 0.01 nT/(m·Hz). This technology has become a frontier research direction in the field of geophysical detection. In this paper, the basic principle of SQUID magnetic measurement technology, the device type (high temperature and low temperature SQUID) and its corresponding system configurations such as magnetometer, magnetic gradiometer, and tensor gradiometer are systematically reviewed. The key progress in the development of SQUID vector magnetic measurement systems at home and abroad in recent years has been analyzed, covering core technologies such as system integration and noise suppression. On this basis, the typical application cases and effects of this technology in mineral resources exploration, military target detection, archaeological investigation and other fields are elaborated in detail. The article also discusses the current status of SQUID preparation process, and looks forward to the future technology development trend and application prospects in view of the challenges faced by superconducting materials, system integration, data processing, etc., so as to provide a reference for the further development of superconducting geophysical vector magnetic survey technology in China.

The Yiwulüshan area in western Liaoning constitutes a key Late Mesozoic deformational tectonic unit in the northeastern segment of the North China craton (NCC). Its multi-stage deformation events preserve critical information regarding the transition of the regional tectonic regime. Through systematic analysis of the macro- and microstructural characteristics of strongly deformed rocks in Yiwulüshan metamorphic core complex, combined with quartz EBSD fabric analysis, this study identifies two distinct phases of extensional ductile shearing events: i.e., Late Jurassic high-temperature (550-650 ℃) ductile shearing (under low amphibolite facies conditions) and Early Cretaceous low-temperature (400-500 ℃) ductile shearing (under greenschist facies conditions). The early-stage deformation is characterized by LS-type tectonites dominated by dextral shearing, exhibiting prominent simple shear properties. In contrast, the late-stage deformation forms L=S type tectonites with sinistral shearing behavior, where the contributions of simple shear and pure shear are comparable. Zircon U-Pb geochronological constraints indicate that these two phases of events occurred during 156.9-146.7 Ma (Late Jurassic) and 132.6-126.8 Ma (Early Cretaceous), respectively. Analysis of the recrystallized grain size of quartz reveals that the high-temperature shear zone was associated with lower differential stress (20.53-22.16 MPa) and higher strain rate (8.41×10-13-5.56×10-11 s-1), whereas the low-temperature shear zone showed the relative slower strain rate (differential stress: 20.62-24.07 MPa; strain rate: 1.34×10-15-9.69×10-13 s-1). The early high-temperature extensional deformation is linked to the transition of the tectonic regime in the northeastern NCC—from the north-southward closure of the Mongol-Okhotsk Ocean to the subduction of the Paleo-Pacific plate. The late low-temperature extensional deformation is related to the roll-back of the subducting Paleo-Pacific plate.

The Fanjiatun Formation in central Jilin, situated on the northern margin of the North China craton, represents a key geological unit for constraining the closure of the eastern Paleo-Asian Ocean. Systematic petrography, detrital zircon U-Pb geochronology, Lu-Hf isotopes, and whole-rock geochemical analyses were performed on its metasedimentary rocks. The youngest detrital zircon population yields a weighted mean age of （233.6±5.0) Ma (N = 11), constraining the maximum depositional age to not earlier than the Late Triassic. Whole-rock geochemistry (Al2O3/TiO2=24.65-63.69, avg. 37.84) and elemental ratios (La/Sc, Th/Sc, Cr/Th, Eu/Eu*) indicate felsic to intermediate upper-crustal sources. Detrital zircon age spectra and predominantly positive  εHf(t) values indicate provenance mainly from the Northeastern block and the northern margin of the North China craton. Tectonic discrimination parameters together with time-series variations in zircon trace elements reveal a transition from compressional orogenesis to extensional stabilization in the study area, and suggest that Paleozoic to Early Mesozoic crustal evolution was characterized by three episodes of thinning and two of thickening, closely coupled with the late subduction-closure regime of the eastern Paleo-Asian Ocean.

The tectonic evolution of the Paleo-Asian Ocean exerted a decisive control on the formation and evolution of the East Asian continent, profoundly influenced magmatic activity, stratigraphic development, and tectonic frameworks within the Central Asian orogenic belt. However, the final closure timing of its eastern segment remains controversial. This study applies machine learning techniques to reconstruct Triassic crustal thickness variations along the eastern segment of the northern margin of the North China craton and adjacent regions, thereby providing new constraints on the mechanism and timing of the final closure of the Paleo-Asian Ocean. During the Early-Middle Triassic, average crustal thickness reached its maximum of approximately 66 km in the Siping area of Jilin Province, a region concurrent with adakitic magmatism. Crustal thickness generally decreased eastward, where the lithological assemblage is dominated by calc-alkaline intermediate-acidic intrusive rocks. These findings suggest that the Paleo-Asian Ocean underwent closed first in the Siping area of Jilin Province in the Early-Middle Triassic, triggering pronounced crustal thickening. In contrast, the easternmost Yanbian area remained an active tectonic seaway, evidenced by crustal thickness comparable to that of normal continental crust. During the Late Triassic, the eastern segment of the northern margin of the North China craton and adjacent regions exhibited an eastward-increasing crustal thickening trend, reaching a maximum thickness of 66 km in the Yanbian area of Jilin Province, again accompanied by synchronous adakitic rocks. Meanwhile, regions like western Liaoning Province and central Jilin Province, which had thickened earlier, now experienced significant crustal thinning accompanied by the emplacement of Late Triassic bimodal igneous rocks. These observations indicate that final closure of the Paleo-Asian Ocean occurred in the Yanbian area during the Late Triassic, while the previously closed western segments transitioned from a collisional-compressional to a post-collisional extensional environment. The systematic spatial-temporal variations in Triassic crustal thickness, integrated with contemporaneous igneous rock assemblages, further confirm a scissor-like west-to-east diachronous closure model for the eastern segment of the Paleo-Asian Ocean, culminating in the Late Triassic.

Sulfide and carboxymethyl cellulose (CMC) stabilization dual-modified nano zero-valent iron (S-CMC-nZVI) exhibits high reactivity and strong mobility, demonstrating significant potential for remediating organically contaminated groundwater. However, the effects of common groundwater anions on its surface-modified layer and contaminant degradation performance remains unclear. This study investigated the mechanisms and effects of common groundwater anions (SO₂^-4, HCO^-3, NO^-3, Cl^-) on the degradation of nitrobenzene by S-CMC-nZVI, using nitrobenzene as the target pollutant. The results showed that the presence of NO^-3 and Cl^- did not affect the sulfidation degree of the S-CMC-nZVI surface modified layer or the degradation efficiency of nitrobenzene. The addition of SO₂^-4 or HCO^-3 led to a reduction in the sulfidation degree of the surface modification layer, causing peeling and increase in the content of Fe2+ and S2- in the solution. Consequently, the actual n(S)/n(Fe) molar ratios of the material decreased to 0.013 2 and 0.019 1, respectively. The FeS and Fe²⁺ produced by the peeling of the sulfide layer can promote the degradation of nitrobenzene. However, SO₂^-4 will cause the formation of iron oxides on the surface of S-CMC-nZVI, thereby inhibiting the sustained degradation of nitrobenzene. In contrast, HCO^-3 accelerated the decomposition of the oxide layer, facilitating the sustained degradation of nitrobenzene, with a maximum efficiency of 99.6%. This study provides a theoretical reference for the efficient application of S-CMC-nZVI in groundwater remediation.

The Qikou sag in the Bohai Bay basin, as a significant Cenozoic depression basin in the eastern North China craton, holds key implications for understanding regional tectonic-sedimentary responses and hydrocarbon accumulation mechanisms during the Paleogene. This study presents a systematic analysis of detrital zircon U-Pb geochronology and trace elements from clastic rock samples of the first (Es1) and second (Es2) members of the Shahejie Formation, obtained from three coring wells (X, Y, Z) in the southern Qikou sag. Integrated with provenance contribution inversion and tectonic setting discrimination, we investigate the controlling effects of the Paleogene tectonic background on the provenance system. Results reveal distinct detrital zircon age spectra between Es1 and Es2 samples: Es1 samples are dominated by age peaks at 120 Ma, 284 Ma, 1 866 Ma, and 2 515 Ma, whereas Es2 samples exhibit clusters at 252-246 Ma, 320-291 Ma, 1 882-1 877 Ma, and 2 542-2 532 Ma. The primary source of the Es1 sediments, according to provenance analysis, was the northern domain of the plate-margin orogenic belt bordering the North China block. Additional provenances included the Jiaodong and Liaodong Peninsulas. In contrast, Es2 sediments were primarily sourced from the Central Asian orogenic belt and the Sulu orogenic belt. Provenance contribution modeling further reveals that Es1 was mainly supplied by the Jiaobei (76.48%), Jiaodong (12.14%), and Liaodong (6.65%) regions, whereas Es2 was significantly influenced by the Central Asian orogenic belt (9.46%) and the Sulu orogenic belt (5.65%). Based on cumulative curves of the time difference between zircon crystallization and deposition ages (CADA) and the evolution of regional fault systems, this study proposes that the Qikou sag was generally under an extensional tectonic setting during the Oligocene. However, a significant provenance shift occurred from Es2 to Es1, reflecting a tectonic transition from a NE-trending to an approximately EW-trending fault system. This shift led to a change in sediment routing from NS to EW, further evidencing the deep-seated control of regional stress field transformation on tectonic-sedimentary processes in the basin under the influence of Pacific Plate subduction.

Northeast China located at the intersection of the northern margin of the East Asian Monsoon and the westerlies, is highly sensitive to global climate changes. The lake sediments in this region feature strong continuity and abundant information carriers, making them ideal for reconstructing the evolution of paleo-environments and paleo-ecosystems. This study systematically reviews the climate changes, ecosystem responses, and impacts of human activities recorded by lake sediments in Northeast China since the last glacial maximum (LGM). Research shows that the climate in Northeast China generally showed a pattern of being dry and cold during the LGM and warm and humid during the Holocene. However, since the last deglaciation, spatiotemporal heterogeneity may exist in hydroclimatic variations on a millennial scale, and the quantitative temperature reconstructions also exhibit significant uncertainties and regional differences. Dust in Northeast China is mainly sourced from the deserts in northern China and the arid regions of Mongolia. Its flux and intensity variations are closely related to climate changes and human activities. Vegetation gradually evolved from the frigid grassland during the LGM to the coniferous-broadleaved mixed forest during the Holocene, and the lake ecosystem underwent phased transformations following changes in hydrology and nutrient status. In modern times, human activities have become an important driving factor of environmental change, leading to the accumulation of lake pollutants, an increase in dust input, and regional ecosystem degradation . High-resolution multi-proxy integration, the identification of human-nature coupled processes, and the integration of models and records should be strengthened in future research. These are better for understanding regional environmental evolution mechanisms and improving future prediction.

To compare the differences in flow and heat transfer properties between tensile and shear fractures, this study used a custom-built flow and heat transfer testing device to conduct flow and heat transfer experiments on granite samples containing either a single tensile fracture or a single shear fracture. The experiments were respectively performed under constant temperatures of 50, 100, 150, and 200  ℃, while the confining pressure in each test was gradually increased from 5 MPa to 20 MPa. The results show that, in terms of flow properties, both the hydraulic aperture and permeability of the tensile and shear fractures decrease with increasing confining pressure. However, the hydraulic aperture and permeability of shear fractures are higher than those of tensile fractures, with the hydraulic aperture being approximately 20%-24% higher and the permeability about 44%-56% higher. In terms of heat transfer, both the heat extraction rate and overall heat transfer coefficient decrease with increasing confining pressure, but shear fractures exhibit higher values at all tested temperatures. Specifically, the heat extraction rate and heat transfer coefficient of shear fractures are about 140% higher at 50  ℃ and about 80%-84% higher in the range of 100-200  ℃. These results demonstrate that shear fractures show better flow and heat transfer properties than tensile fractures. These findings on the flow and heat transfer properties of tensile and shear fractures under different temperature and confining pressure conditions are of great importance for understanding fluid flow and heat transfer behavior in real enhanced geothermal reservoirs.

The final closure of the eastern segment of the Paleo-Asian Ocean remains a hotly debated topic in geological research. However, the eastward extension of the Solonker suture and its exact closure location are further complicated by thick Mesozoic cover on the western margin of the Songliao basin. The recent discovery of the Tuquan ophiolite, which constitutes an important component of the ophiolitic fragments within the Solonker suture, provides key constraints on the eastward extension of the suture. LA-ICP-MS zircon U-Pb dating yields ages of (265.5 ± 3.5) Ma for serpentinized peridotite and (276.5 ± 4.6) Ma for gabbro are, indicating formaion of the Tuquan ophiolite from the late Early Permian to Middle Permian. Combined with the geochemical characteristics, it suggests that the Tuquan ophiolite originated in a forearc tectonic setting during the Early to Middle Permian, coinciding with bidirectional subduction and consumption of the Paleo-Asian Ocean. These findings further reveal that the final subduction and collision of the Paleo-Asian Ocean persisted at least until the late Permian. Collectively, the Tuquan ophiolite serves as direct geological evidence for the eastward extension of the Solonker suture and provides new constraints on the Late Paleozoic tectonic evolution of the southeastern Central Asian orogenic belt.

The ground-air frequency-domain electromagnetic (GAFDEM) method has broad application prospects in studying deep geological structures in complex terrains. However, current studies and applications mainly focus on ground resistivity imaging, with limited in-depth studies on the measurement of induced polarization effects. This paper aims to systematically investigate the influence of polarization effects on GAFDEM measurement results and proposes a method for simultaneous imaging of apparent resistivity and apparent polarizability. To this end,  based on Maxwell’s equations and the Cole-Cole model,a forward model of electric-source ground-air frequency-domain electromagnetic response considering polarization effect  is established.  The influence of parameters such as resistivity and polarization rate on the airborne magnetic field is analyzed, and a method for simultaneous calculation of apparent resistivity and apparent polarizability is proposed using Sobol sensitivity analysis and particle swarm optimization. Finally, simulation experiments are conducted to verify the effectiveness of this method in identifying low-resistivity, high-polarization targets. The results show that the apparent resistivity curves for all models exhibit a characteristic dip at the low-resistivity target layer, intuitively reflecting the low-resistivity properties of the target layer. Models including polarization effects display high values at the target layer, with the anomaly amplitude increasing as polarization rate rises. The zero-polarization model shows a relatively flat apparent polarization curve. Experimental results further indicate that both ground resistivity and polarizability significantly affect the amplitude of the airborne magnetic field, with low-resistivity, high-polarization anomalies generating significant magnetic field response anomalies. 

To reveal the near-surface structural characteristics of the Jiamusi block-Nadanhada terrane, this study applies the first-arrival traveltime tomography method based on  deep seismic reflection profile data to invert and obtain the  near-surface P-wave velocity structure model of the study area, and further depicted the spatial distribution characteristics of the fault zones. The inversion results show that the thickness of the sedimentary cover generally exhibits a regional distribution pattern of being thicker in the west and thinner in the east. There is significant lateral heterogeneity in the vicinity of the main fault zones. Specifically, the thickness of the sedimentary cover within the Jiamusi block is relatively thin (0.5-0.7 km), which increases rapidly when crossing the Dunhua-Mishan fault zone and the Yuejinshan fault zone, with the maximum local thickness exceeding 2 km. In contrast, the thickness of the sedimentary cover within the Nadanhada terrane is generally less than 0.5 km. The Yuejinshan fault zone is manifested as a significant lithospheric-scale velocity gradient zone, which further reveals its nature as a boundary fault separating different tectonic units. Meanwhile, the Dunhua-Mishan fault zone is characterized by a nearly vertical low-velocity anomaly zone, indicating that the physical properties of the rocks wihtin the fault zone have been weakened due to fragmentation caused by tectonic activities.

As the most significant geological units in Northeast China, the tectonic nature and evolutionary history of the Jilin-Heilongjiang high-pressure belt remain controversial. To reveal the crust-mantle-scale structure of this belt and constrain the subduction-accretion processes of the Heilongjiang Ocean, this paper constructs a deep geophysical model based on magnetotelluric  and deep seismic reflection data. The model reveals pronounced lateral heterogeneity in both electrical conductivity and seismic reflectivity across different tectonic units. A key finding is a west-dipping zone of high resistivity and strong seismic reflectivity, which extends from the crust into the lithospheric mantle within the tectonic convergence zone. We interpret this feature as a fossil subduction zone associated with the closure of the Heilongjiang Ocean. In the upper crust, both the Heilongjiang and the Zhangguangcai Range complexes exhibit consistent high resistivity and short, arcuate reflection packages. In contrast, the middle to lower crust of the Zhangguangcai Range is characterized by a pronounced high-conductivity anomaly and a distinctive reversed U-shaped reflection pattern. Integrating these geophysical observations with existing geological understanding, we propose that the Zhangguangcai Range complex is not an integral part of the Songliao block. Instead, our data support a model of westward subduction of the Heilongjiang Ocean, with successive accretion of the Zhangguangcai Range and the Heilongjiang complexes as major components of the accretionary wedge. The Zhangguangcai Range complex thus records the early stage of the subduction-accretion process.

Spatiotemporal analysis of recurring slope lineae (RSL) heavily relies on the effective integration and correlation mining of multi-source heterogeneous data to provide a reliable scientific basis for understanding RSL formation mechanisms. Based on this, an RSL knowledge graph covering the Coprates and Melas Chasma within the Valles Marineris canyon system was constructed using the Neo4j graph database, with HiRISE (high resolution imaging science experiment) high-resolution remote sensing images as the primary data source. Subsequently, key topographic and seasonal factors controlling RSL distribution were identified through graph queries and spatiotemporal correlation analysis. Furthermore, a quantitative relationship model between RSL activity, slope aspect, and solar longitude was established. Based on 364 time-series images from 101 RSL sites, the spatiotemporal distribution patterns of RSL were systematically analyzed. Finally, by integrating previous observational results and climate event records, the effectiveness of the constructed knowledge graph in revealing RSL spatiotemporal characteristics was validated. The results indicate that RSL distribution exhibits a significant westward preference, and seasonal activity is closely coupled with slope aspect, forming an alternating intra-annual activation pattern. Following the MY34 global dust storm, RSL activity was observed on all slope aspects in Garni Crater, marking a stark contrast to previous years when activity was limited to specific aspects, confirming the significant impact of climatic events on RSL scale.

To address the technical challenges associated with enhanced geothermal systems, including hydraulic fracturing stimulation, induced seismicity, and uncertainties in reservoir permeability, this study explores an alternative development pathway with improved environmental compatibility and operational stability, namely the closed-loop geothermal system (CLGS). Through a comparative analysis, the technical advantages of CLGS are systematically clarified. First, the research progress on the mechanical stability and efficient heat extraction modes of CLGS under long-term operation is comprehensively reviewed. Particular emphasis is placed on analyzing the effects of different injection-production parameters on heat extraction performance, and the thermal energy extraction efficiency of various heat production modes is comparatively evaluated. Furthermore, the stability mechanisms of the wellbore under coupled thermo-fluid-solid processes are investigated. The results indicate that, for CLGS, a spiral wellbore configuration can significantly enhance long-term heat exchange capacity, with the average heat exchange per unit wellbore length increased by 23.73% over a 50 a operation period. Intermittent heat extraction markedly improves heat transfer efficiency, resulting in an average thermal output increase of 3.95 kW and a cumulative heat production enhancement of 34.6%. In addition, the injection rate is demonstrated to play a critical regulatory role in the evolution of the heat extraction cycle and the stress disturbance process of the wellbore.

Deep continental scientific drilling is essential for directly sampling Earth’s interior and unraveling the mechanisms of continental formation and evolution. The sophistication of such equipment reflects a country’s capability in deep Earth exploration. This paper systematically reviews the development status, core challenges, and future trends in key technologies for deep scientific drilling equipment, with a focus on extreme downhole conditions such as high temperature, high pressure, and high load. Through literature review and case studies(including the Kola Superdeep Borehole, the Continental Deep Drilling Program of Germany(KTB),Songke-2 Well of China, and Well Shendi Take-1 of China)this paper analyzes critical technical issues such as precise weight-on-bit control, wireline coring, efficient tripping, drilling fluid cooling and circulation, and intelligent operation and maintenance. China has domestically developed systems like the “Crust-1” 10 000-meter rig and the Well Shendi Take-1 project have reached world-class levels in core quality and automation, achieving breakthroughs in top drive systems, wireline coring winches, automated wellhead equipment, and intelligent mud control. Nevertheless, gaps remain in high-temperature/high-pressure sensing, dynamic sealing in ultra-deep holes, and intelligent decision-making models. Future drilling equipment should evolve toward automation, intelligence, environmental sustainability, modularity, and rig-free downhole self-propulsion. Promote the evolution of drilling equipment from conventional mechanical tools to “intelligent probes” with geological sensing capabilities. This will provide crucial technological and equipment support for China’s deep resource exploration and energy security.

Since the Paleozoic, Northeast China has experienced the superimposition of multiple paleo-ocean tectonic regimes, including the Panthalassa, Mongol-Okhotsk Ocean, Paleo-Asian Ocean, and Paleo-Pacific Ocean. However, the processes of their superimposition and transition remain poorly understood. The Jiamusi-Khanka block, located at the easternmost end of the microcontinental blocks in Northeast China, represents a key a key tectonic nexus: It marks the final closure of the eastern segment of the Central Asian orogenic belt (Paleo-Asian Ocean tectonic domain), connects to the Mongol-Okhotsk tectonic domain in the northeast, and lies at the core of the superimposed influence of the circum-Pacific (Panthalassa) tectonic domain along the eastern margin of Eurasia. Consequently, it serves as a critical bridge for understanding the superimposition and transition processes among these paleo-ocean tectonic regimes. This study comprehensively analyzes the lithology, geochronology, and geochemical characteristics of the metamorphic basement, sedimentary cover, and peripheral tectonic mélanges of the Jiamusi-Khanka block, reconstructing its tectonic evolution from the Paleozoic to the Mesozoic. The findings provide key constraints on the tectonic regime superimposition and transition processes along the eastern margin of Eurasia. The Paleozoic-Mesozoic tectonic evolution of the Jiamusi-Khanka block can be divided into four stages: (1) Prior to the Early Paleozoic, the Jiamusi-Khanka block, together with other microcontinental blocks in Northeast China, formed a large composite block that originated in the Sayan-Baikal orogenic belt within the Siberian craton and collectively underwent Pan-African metamorphism (~500 Ma). (2) During the tectonic evolution of the Central Asian orogenic belt, these blocks drifted southward to the eastern segment of the orogen around 500 Ma. (3) In the Late Paleozoic, subduction of the Mongol-Okhotsk Ocean or Panthalassa induced a back-arc extension, leading to the opening of the Heilongjiang Ocean. This rifted the Jiamusi block from the composite block and caused its eastward drift, separating it from the eastern segment of the Central Asian orogenic belt. (4) From the Late Triassic to the Early Jurassic, the closure of the Heilongjiang Ocean and the subduction of the Paleo-Pacific Ocean in the east drove the re-amalgamation of Jiamusi block with the adjacent Central Asian orogenic belt. This event marked the final formation of the Central Asian orogenic belt and the regional transition to a new stage dominated by the Paleo-Pacific tectonic regime.

The extensive development of Permian to Jurassic magmatic rocks in the Zhangguangcai Terrane, Northeast China, provides important information for understanding the regional tectonic evolution. This study systematically summarizes the geochronological and whole-rock geochemical characteristics of 266-163 Ma magmatic rocks from this terrane, identifying four distinct episodes of magmatic activity: The 266-240 Ma magmatic activity is mainly composed of adakitic and I-type magmatic rocks, while the 229-210,209-185 and 184-163 Ma magmatic activities are mainly composed of adakitic, I-type and A-type magmatic rocks. Based on analysis of magma sources and tectonic settings, combined with regional geological constraints, we propose that the tectono-magmatic history of the Zhangguangcai Terrane was primarily controlled by the evolution of the Heilongjiang Ocean. Specifically, westward subduction of the ocean beneath the terrane occurred during 266-210 Ma, followed by ocean closure during 210-180 Ma, which culminated in the final collision between the Jiamusi-Khanka block and the Songliao block. The obduction of residual oceanic crust during 180-163 Ma triggered tectonic exhumation and final emplacement of the Heilongjiang accretionary complex. The occurrence of a magmatic lull (240-230 Ma) is attributed to low-angle subduction of the Heilongjiang Ocean. Our findings indicate that the Zhangguangcai Terrane represents a combination of Late Paleozoic to Early Mesozoic accretionary complexes and continental arcs, rather than an ancient block with Neoproterozoic basement.

With the increasing requirements for reservoir precision in oil and gas exploration, the traditional seismic wave propagation theory based on the pure elasticity assumption can no longer effectively describe the dispersion and attenuation characteristics exhibited by seismic waves during propagation caused by rock viscoelasticity and pore structure in complex media. Seismic forward modeling in poro-viscoelastic media has become an important research tool for accurately characterizing such coupling effects, among which the generalized standard linear solid model and its memory variable approach reduce computational complexity by introducing auxiliary differential equations to replace convolution integrals, thus realizing effective simulation of frequency-dependent attenuation. However, under the conditions of complex reservoirs with strong nonlinearity and strong attenuation, traditional algorithms still face the dilemma of balancing computational accuracy and efficiency. This paper introduces the generalized recursive convolution method to convert the time convolution term in the constitutive equation into a high-order recursive formula, directly updating the wavefield state recursively in the time domain, avoiding the global storage of historical data and repeated integral operations, and significantly reducing computational complexity and memory consumption. Numerical experiments show that in the homogeneous model, the proposed method in this paper improves computational efficiency by approximately 9% compared with the traditional memory variable method while achieving higher wavefield amplitude fidelity; In the two-layer anisotropic model, it can depict interlayer reflection and wave mode conversion more clearly than the memory variable method, significantly improving the accuracy of wavefield simulation; And in the complex heterogeneous Marmousi model, this method can effectively simulate the wavefield interference and slow-wave attenuation characteristics under strongly undulating interfaces.