The Luzon Arc in the eastern margin and Sunda-Java Arc in the southern margin of the South China Sea (SCS) are important volcano-seismic belts, with their volcanic glass serving as the main sediment source in SCS. Volcanic glass was identified in a large number of columnar cores to analyze its distribution characteristics, supplemented by ¹⁴C dating and oxygen-carbon stable isotope determination. The results show that the distribution characteristics of columnar volcanic glass are similar to those of surface sediment samples, peaking in the eastern SCS and spreading outward, indicating the primary source is still the Philippine Islands. However, the volcanic provenances from the Sumatra-Java Arc volcano-seismic belt since  Late Pleistocene exceed those from surface sediments. The volcanic glass content of MIS1 in the northeastern SCS is greater than in MIS2, suggesting enhanced volcanic activity of MIS1 in the northern Luzon Arc. The absence of volcanic glass in the northern shelf and slope area of the SCS indicates a lack of recent volcanic activity from the northern South China continent, exerting minimal influence on the near-surface sediments of SCS.

Based on core and cast thin section data, the reservoir characteristics, reservoir controlling factors,  and reservoir evolution of Mesozoic volcanic rocks in block Kenli-16 were studied by means of microscopic identification, scanning electron microscopy, porosity and permeability testing, constant velocity mercury injection, image analysis and burial history analysis. Seven  types of 16 reservoir spaces are identified in block Kenli-16. The reservoir type is pore-fracture type. It is characterized by large pore size and medium-big throat, and belongs to high-quality volcanic rock reservoir. The reservoir is controlled by lithology, dissolution diagenesis, and tectonism and has no obvious relationship with burial depth. The descending order of reservoir quality is tuff, lapilli, volcanic breccia, welded breccia, reworked volcaniclastics, ignimbrite, andesite, and dacite. The fluid contributes greatly to the porosity formed by the dissolution of feldspar porphyry and matrix, the results show that pre-burial weathering and burial fluid dissolution are important stages of reservoir formation. The amygdaloid, intergranular pores, explosive cracks, macroscopic and microscopic cooling fractures, and crypto-explosive fractures were generated during syn-eruption stage, and their contribution rate to pores was limited. The tectonic fractures of pyroclastic lava and lava are mainly formed in the pre-burial stage, the left-lateral strike-slip stress field of Tanlu fault zone in Cretaceous period and the extensional environment of Shahejie stage. The tectonic fractures of pyroclastic rocks are mainly formed in the post-burial stage, the right-lateral strike-slip stress field of Tanlu fault zone in Cretaceous period and the extensional environment of Shahejie stage. In conclusion, pyroclastic rocks that are subjected to strong structural transformation and weathering in shallow buried areas are favorable targets for exploration.

The natural gas reservoir in the deep sand and gravel strata of the Xujiaweizi fault depression in the Songliao basin is a typical unconventional resource type of “low porosity and low permeability”, with locally developed high porosity and high permeability zones, meeting the requirements for tight gas reservoir formation. Using techniques such as thin section identification, scanning electron microscopy, mercury intrusion detection, and two-dimensional nuclear magnetic resonance, an effective analysis of the sand and gravel reservoirs in the Shahezi Formation of the Xujiaweizi fault in the Songliao basin was conducted to reveal the structure of the sand and gravel reservoirs and their impact on productivity. The research results indicate that the lithology of natural gas reservoirs is mainly composed of sandstone and conglomerate, with low compositional and structural maturity. The reservoir space is mainly composed of secondary dissolution pores, and locally developed microcracks connecting pores, which improve the permeability of the reservoir; The distribution range of pore throat radius in gravel reservoirs is large (nanoscale to micrometer scale), belonging to the micropore throat type reservoir. Influenced by rock sorting, clay minerals, and the development degree of carbonates and other cementitious substances, the connectivity of pore throats in gravel reservoirs is better than that in sandstone, and that in coarse sandstone is better than that in fine sandstone. In the vertical direction, the pore throat structure of the fourth sequence is better than other sequences; The porosity of the reservoir is mainly distributed between 0.3% and 8.0%, and the permeability is mostly less than 0.987 0×10^-3 μm². Based on the empirical statistical method combining physical properties and gas production capacity, the minimum flow pore throat radius is estimated to determine the lower limit of porosity for tight sandstone as 3.0%, with a permeability of 0.019 7×10^-3 μm². The lower limit of porosity for tight conglomerate is 2.8%, and the permeability is 0.019 7×10^-3 μm².

 In order to ensure the hydrocarbon enrichment regularities and favorable exploration direction within the 4th Member of Quantou Formation in Wangfu area, seismic, geological, geochemistry, and testing data are used to analyze the main controlling factors and hydrocarbon accumulation mode of conventional and unconventional oil on the basis of reservoir classification and its distribution. There are two kinds of reservoirs in Wangfu area, conventional low-permeability reservoir and unconventional tight oil, and they are in order distribution. The hydrocarbon accumulations in the 4th Member of Quantou Formation are controlled by source rock, structure, fault, and reservoir. The distribution of low-permeability reservoir is controlled by strong hydrocarbon expulsion mudstone, while residual pressure is the main power for tight oil. The structure of the 4th Member of Quantou Formation is almost complete before the hydrocarbon expulsion, and north uplift with a low fluid potential is the target area for low-permeability reservoir migration. The open faults in NW direction are favorable channels for low-permeability reservoir migration in lateral and tight oil in vertical. Relatively high reservoir quality is the key factor of tight oil accumulation and low-permeability reservoir productivity. We recognized four kinds of accumulation modes in Wangfu area, such as “overpressure drive, vertical migration and enrichment in sweet points” within the deep depression, “fluid potential drive, lateral migration along the open fault and assemble in ancient culmination” among north uplift, “reservoir and source butt to butt, overpressure and fluid potential relay drive, fault and sandstone migrate together” in west steep slope, and “overpressure and fluid potential drive, sandstone migration and enrichment in sweet points” around gentle slope in the east.

The origin of dolomite is a key problem in Cambrian-Ordovician exploration in Tadong area of Tarim basin. In view of the above problem, the rare earth element (REE) characteristics of 30 dolomite samples from Well Milan 1 were analyzed based on the observation of cores and thin sections. The results show that the NASC normalized REE distribution patterns of all samples can be classified into five types: the type of δCe negative anomaly, the type of δEu negative anomaly, the type of δEu strong positive anomaly, the type of δEu positive anomaly, the type of “V” shape. Further study found that the δCe of most samples is negative abnormal, indicating that most dolomites have been affected by evaporation pump dolomitization, and many samples also show diverse δEu anomalies and distribution characteristics, indicating that many dolomites were transformed by buried fluids or (and) multiphase hydrothermal fluids in the late stage. Among them, dolomite with fine grains is mainly formed by an evaporation pump, and dolomite with large grains may be formed in a buried or hydrothermal environment, while siliceous dolomite is mostly subjected to a hydrothermal reaction.

The Wudun depression belongs to an area with a low degree of exploration. The oil source conditions in the Lower Jurassic outcrop area are good, and the oil and gas show well in many wells drilled. However, the sequence stratigraphic framework of the basin, the sequence spatial evolution characteristics and sedimentary distribution rules are not clear, which restricts the later exploration deployment, which restricts the next exploration deployment. The research on the sequence stratigraphic division and regional sequence stratigraphic framework of  Middle and Lower Jurassic in Wudun depression is carried out by comprehensively applying the data of logging, seismic, core, and analysis data. At first, the spectrum-attribute-trend analysis of logging, time-frequency analysis, geochemical analysis and other methods are used to divide the sequence, and six third-order sequences and 28 fourth-order sequences are divided. Then, the matching wavelet decomposition and reconstruction method is used to improve the resolution of seismic data, and the seismic multi-attribute dimensionality reduction fusion technology and multi-scale matching with well-seismic joint are used for sequence analysis, and then the Jurassic sequence stratigraphic framework is established in this area. At the same time, the logging sequence division results and seismic multi-attribute fusion analysis results are cross-verified to clarify the spatial evolution characteristics of the sequence. At the same time, the logging sequence division results and seismic multi-attribute fusion analysis results are cross-verified to clarify the spatial evolution characteristics of the sequence. On the basis of high-precision sequence analysis, under the constraints of fine structural interpretation and sedimentary palaeogeomorphology, the distribution characteristics of sedimentary facies belts at key horizons are finally determined by using the results of sequence interpretation at different levels. A set of ideas and methods for the establishment of regional high-precision sequence stratigraphic framework and the study of sedimentary laws in areas of low exploration degree have been formed.

Paleosol is a significant carrier for studying paleoclimate. Presently, the research on pedogenesis principally focuses on the migratory behavior of elements and the evolutionary process of pedogenesis, with limited reports on the manifestations of pedogenesis. The Upper Cretaceous Tangbian Formation in Xinjiang basin is dominantly composed of red sandstone with large cross-beddings, which is a typical representative of Cretaceous greenhouse climate terrestrial deposits in South China. Based on detailed field investigation, petrological and geochemical methods were employed to study the pedogenesis of red sandstone during the Cretaceous Tangbian Formation and explore paleoclimate characteristics of the Xinjiang basin during the Upper Cretaceous. The red sandstone of Tangbian Formation in the study area is primarily medium-grained arkose. The sediments have universally experienced pedogenesis, the key identification features of red sandstone include clay films on the edge of the detrital grains, micritic-sparry carbonate cement and gleization. The CIA (Chemical Index of Alteration) ranges from 50.20 to 83.30 (58.08 on average), indicating that the red sandstone is at a low level of chemical weathering. The analysis of microelement and the recognition of pedogenesis collectively indicate that the sandstone in the study area was formed in a hot and dry paleoclimate. This may be attributed to the high coastal mountain system that emerged during the Upper Cretaceous period in Eastern China, hindering the flow of moist water vapor from the Paleo-Pacific Ocean into the inland areas of Southeast China and forming a sedimentary paleogeographic environment dominated by aridity and torridity.

Numerical simulation technology has emerged as a crucial tool for exploring geodynamic processes. This paper reviews the current applicationsof numerical simulations in geodynamics, focusing on key methods, algorithms, and codes, with outlining future development prospects. By discretizing continuous equations and employing numerical algorithms, these simulations efficiently model geological processes and predict dynamic changes in the Earth’s system. The paper systematically discusses the principles, characteristics, and applicable conditions for mainstream numerical methods, including the finite element method, finite difference method, boundary element method, and finite volume method. It explores the finite element method for simulating tectonic stress fields and fault dynamics, the finite difference method for seismic wave propagation, and the boundary element and finite volume methods for fault mechanics and pore fluid flow. A comparative analysis highlights the strengths and weaknesses of each method, indicating that coupling various numerical methods is a key future direction in geodynamics. Furthermore, this paper anticipates the growing significance of numerical simulation technology in Earth system scientific research, propelled by advancements in high-performance computing and the era of big data.

The Dajinshan area is located in the Ning-Wu ore concentration zone along the Middle-Lower Yangtze metallogenic belt at the northern margin of  Yangtze plate. The area has favorable geological conditions for mineralization and shows potential for further prospecting. To identify the prospecting potentials in Dajinshan area, this study performed a correlation analysis between induced polarization(IP) medium gradient survey and soil geochemical survey results. The results show that a NW-trending fractured and broken zone exhibits high resistance and chargeability anomalies, which are indicative of controlling mineralization. These anomalies can thus serve as indirect guides for prospecting. Ten comprehensive anomalies were identified through soil geochemical surveys that indicate significant prospecting potential. Two drill holes were drilled in areas where high resistance, chargeability, and strong Au anomalies overlapped, leading to the discovery of three copper orebodies and three pyrite orebodies, achieving a major prospecting advancement. By comparing these findings with similar metallogenic characteristics (Dalinggang gold-copper deposit, Nanmentou copper deposit), and analyzing the primary halo in drill core samples, it is believed that the deeper parts of the Dajinshan area likely have promising prospecting potentials. Based on the ore-bearing rocks, tectonic environment, and the discovery of porphyritic monzonite granites in the deeper parts of porphyry-type copper-gold deposits, it is believed that blind orebodies may exist at depth, suggesting the potential for porphyry-type copper-gold deposits.

Erdaodianzi gold deposit located approximately 2 kilometers northwest of Erdaodianzi Town, Huadian City, Jilin Province, is a large gold deposit situated at the contact zone of Paleozoic schist, gneiss, and Mesozoic Early Jurassic granodiorite. It is controlled by a tectonic magmatic fluid mineralization system and NW-trending compressive and torsional faults. Our new research on mineral fluid inclusions, H-O-S-Pb isotopes, and mineralization ages has provided insights into its genesis and geological background. The main types of fluid inclusions are mainly gas-liquid two-phase and liquid phase inclusions, with uniform temperatures between 218.7 and 347.8 ℃, fluid salinities of 3.33% to 14.57%, densities of 0.69 to 0.89 g/cm3, and a mineralization depth of less than 1.4 km. The fluid inclusion δ¹⁸O_H2O values range from 5.23‰ to 9.50‰, δD values range from -83.8‰ to -111.1‰, and δ³⁴S values range from -8.25‰ to -2.00‰, with ratios of ²⁰⁶Pb/²⁰⁴Pb、²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb varying from 16.721 0 to 18.489 8,15.340 0 to 15.623 0 and 36.488 0 to 38.373 0, respectively. These characteristics reveal a medium temperature hydrothermal deposit with ore-forming fluids sourced from magma, involving water-rock interactions with surrounding rocks and the addition of atmospheric water. The mainly ore-forming material is derived from magma mixed with stratigraphic materials. Additionally, single grain zircon LA-ICP-MS U-Pb ages of （(192.7 ± 1.6) Ma） from biotite granodiorite align with the regional gold mineralization era. Comprehensive analysis suggests that the deposit is a magmatic hydrothermal gold deposit related to plutonic magmatism, suitable for an active continental margin orogenic extension environment influenced by the subduction of the Peleo-Pacific plate.

During  Late Ordovician and Early Silurian, multiple layers of K-bentonite were deposited on  Yangtze block and surrounding areas, indicating frequent volcanic activity. Previous studies primarily focused on the chronology of the Ordovician-Silurian boundary. This study carried out a lithostratigraphic division of the Shimenkan section in Yongshan County, Yunnan Province, western edge of  Upper Yangtze, dividing it into the Jiancaogou Formation, Wufeng Formation, Longmaxi Formation Ⅰ, Longmaxi Formation Ⅱ and Xintan Formation. Eleven K-bentonite layers, each over 1 cm thick, were identified. Zircon U-Pb dating of K-bentonite at the boundaries of each formation yielded ages of (449.9±4.3) Ma for the base of Jiancaogou Formation, (443.8±1.0) Ma for the Wufeng and Longmaxi boundary, (438.5±3.5) Ma for the Longmaxi Formation Ⅰ  and Ⅱ  boundary, and (437.8±5.6) Ma for the top of the Xintan Formation. The trace elements characteristics of zircons suggest that  Late Ordovician-Early Silurian bentonites originated from a subduction-collision orogenic environment due to the convergence of  Cathaysian and Yangtze blocks. Additionally, the first layer of bentonites reflects the presence of residual ocean basins in South China, with its zircon U-Pb age (449.9±4.3) Ma marking the initial time of Guangxi movement on the western margin of  Upper Yangtze. However, there is no direct link between high-frequency volcanic activities with mass extinction events.

To study the effect of thermal-mechanical coupling on fracture permeability evolution of enhanced geothermal systems (EGS), flow-stress loading and unloading coupling experiments were carried out on granite samples with rough single fracture under the normal temperature (e.g., 25 ℃) and high temperature (e.g., 150 ℃ and 180 ℃) conditions, respectively. The confining pressure of loading and unloading processes was between 5 MPa and 30 MPa. The evolution law of fracture permeability induced by elastic-plastic deformation was analyzed during stress loading and unloading. The results show that the fracture permeability has a logarithmic negative correlation with the confining pressure. When the temperature was 25, 150 and 180 ℃, the fracture permeability decreased by 78%, 90% and 92% in the loading stage, and only recovered by 63%, 26% and 19% in the unloading stage. This indicated that the rough fracture surface has occurred plastic deformation during loading and unloading processes, which leads to permanent attenuation of fracture permeability. When the temperature increased from 25 ℃ to 150 ℃ and 180 ℃, the permeability attenuation caused by plastic deformation increased from 15% to 64% and 73%, respectively. This indicated that the effect of plastic deformation on the fracture surface is related to the crushing of mineral particles, which becomes more significant in high temperatures.

In order to reasonably determine the creep long-term strength σs of marble under the coupling effect of hydration freeze-thaw, uniaxial compression tests and uniaxial compression creep test were carried out with three solution environments of acid, medium and alkali and different freeze-thaw cycles as the experimental control factors in an open-pit slope in northwest Hubei Province. Then, the long-term strength of marble was compared and analyzed by combining transition creep method, isothermal stress-strain curve cluster method, steady-state creep rate stress relationship method, strength failure time relationship method, and two new methods (long-term strength prediction method based on stress-strain curve and improved steady-state creep rate stress relationship method). The results show as follows: 1) under the same number of freeze-thaw cycles, the instantaneous and long-term strength under acidic environment is the smallest, followed by alkaline environment, and the neutral environment is the largest. 2) By using transition creep method, isothermal stress-strain curve cluster method, steady-state creep rate stress relationship method, long-term strength prediction method based on stress-strain curve, and improved steady-state creep rate stress relationship method, the average long-term strength values of the marble under different solution environments and freeze-thaw cycles is 46.70, 41.21, 39.74, 43.92 and 43.67 MPa, respectively. 3) The long-term strength prediction method based on stress-strain curve does not require time-consuming creep test, and can quickly predict the long-term strength of rocks based solely on the stress-strain curve determined by compression tests. Compared with traditional methods, the improved steady-state creep rate stress relationship method eliminates the strong subjectivity of taking inflection points.

In order to study the stress characteristics of micro-steel pipe pile-anchor support in soil-rock-bound stratum, as well as the internal force changes of steel tubular pile at different excavation depths and after the completion of anchor cable and anchor rod construction, a field test was carried out in a subway station in Qingdao. The foundation pit was strengthened by using the third-order micro-steel pipe pile combined with anchor cable and anchor rod, and the internal force test was carried out on two test piles in the first order of the foundation pit. The steel pipe piles in different excavation depth, anchor and anchor cable construction after the completion of the internal force of change. The results show that the bending moment near the excavation surface and the top of the pile is large, the measured bending moment value is up to more than 15 kN·m. The anchor cable lock can effectively suppress the development of bending moment. The law of the internal force changes in the pile body is obviously related to the earth rock geological conditions, and the maximum positive bending moment is 32.43 kN·m.  

For complex spatial distributed high and steep rock slopes, traditional surveying methods still face challenges in efficiency and accuracy. To obtain rock mass structural parameters quickly and accurately for evaluating the stability of rock slopes, a multi-attitude close-range photogrammetry method using unmanned aerial vehicles (UAVs) is proposed. Firstly, the conceptual slope model was established rapidly by measuring key points on site, and the flight route planning and attitude control model were combined to quickly plan the flight routes and camera orientations. Then, by implementing software on the remote controller instead of a PC, the method achieves real-time, on-site, coarse-flight-free, rapid multi-attitude close-range photogrammetry with high-quality image acquisition of high and steep slopes at millimeter resolution. Finally, the method is validated through a multi-attitude close-range photogrammetry experiment on a high and steep slope in Jingyue district, Changchun City, Jilin Province. The feasibility and reliability of the method are assessed based on model accuracy, texture clarity, and orientation interpretation accuracy. The results show that the accuracy of the model in x, y and z directions is 0.018, 0.016, and 0.033 m, respectively. The accuracy of dip direction and dip angle interpretation is 3.1° and 2.6°, respectively. Compared with conventional close-range photogrammetry, the multi-attitude close-range photogrammetry significantly enhances texture details and greatly reduces surface distortion effects. The Chinese PCQI (perceived clarity quality index) values are higher, while the NIQE (natural image quality evaluator) values are lower, indicating better image quality. The result of PCQI and NIQE metrics both showed that the image captured with 45° lateral tilt and 30° vertical tilt provide higher quality than those from other tilt angles. Multi-attitude close-range photogrammetry outperforms conventional close-range photogrammetry, effectively reducing dead angles and mitigating texture distortion, thereby substantially improving model image quality. The model was verified to be reliable by  point accuracy, distance, and orientation interpretation accuracy assessments. The rock mass structural parameters, such as trace lines, orientations, dominant joint sets, and RQD (rock quality designation), interpreted by this method provide reliable foundational data for slope stability evaluation.

In order to study the micro shear mechanical properties of clay during the shear process, a micro mechanism analysis of the shear mechanical properties of this silty clay was conducted using laboratory test results and discrete element simulation methods. Based on the results of experiments, a PFC^2D model that conforms to the shear test characteristics of clay was established to compare and analyze some micro parameters of clay and sand during the shear process. Then micro stress, micro deformation, and micro displacement of clay at different shear stages were analyzed, and the macroscopic shear mechanical properties of the sample were analyzed from a micro perspective. The results show that the shear stress in clay is mainly provided by the force chain between particles. The particles in clay are smaller and the force chain is finer, resulting in a lower bearing capacity. The maximum bearing capacity of the force chain in clay is only about 0.77 kN, while standard sand can reach 1.75 kN. Under the condition of overconsolidation, clay exhibits significant strain softening during shearing, which is related to the directional arrangement of particles and the reduction in the number of strong chains between particles. During the shearing process, the middle coordination number of the clay decreased by 1.70, which is due to the displacement of the clay particles, and an arch like structure between the particles were formed to increase the porosity, which results in an increase in the volumetric strain of the clay. During the shearing process of clay, the contour lines of particle displacement form an approximately diamond shaped area in the middle region of the PFC^2D model, and the shear band of clay is a narrow strip with relatively consistent displacement when sheared.

This study focuses on the adsorption characteristics of zinc in soil at different depths of a certain abandoned rare earth mine in the south of Ganzhou, Jiangxi Province. Static batch experiments were conducted. X-ray diffraction (XRD) and X-ray absorption fine structure spectroscopy (XAFS) were used to study the major phases and morphological changes of zinc in soil before and after adsorption reaction, in order to investigate the adsorption mechanism and mobility of zinc in soil. The results show that the adsorption equilibrium process of zinc in soil is fast. The adsorption capacity of soil for zinc gradually decreased from the surface soil to the deep soil and then to the middle soil. The pseudo-second-order kinetic model and Langmuir equation can describe the adsorption process of zinc in soil well. XRD and XAFS results show that iron and manganese exist mainly in the form of iron hydroxide and mixed valence state manganese oxide in soil. Differences in the physical and chemical properties of soil layers affect the adsorption behavior of soil towards zinc. Compared with clay minerals, iron and manganese oxides have a more significant effect on the adsorption of zinc in soil. XAFS indicates that the local coordination mode of zinc changes from Zn-O tetrahedron to a mixed coordination mode of Zn-O tetrahedron and octahedron after adsorption reaction. A complex similar to sulfate may form on the soil surface after the reaction. The form of zinc in soil changes from basic carbonate to a mixed form of sulfate and basic carbonate after adsorption reaction. Due to the influence of soil pH, the capacity of zinc retention in soil is limited. The readily available zinc in soil is prone to migrate downward with rainfall. The zinc content in soil increases with depth. The study provides a scientific basis for the prevention and control of zinc pollution in soil and groundwater in mining areas. 

In order to prepare calcium-iron modified biochar, optimize the removal effect of single iron-modified biochar on Pb(Ⅱ), and obtain biochar that can efficiently remove Pb(Ⅱ) from water and is easy to recycle, in this study, poplar and bamboo were used as raw materials to prepare eight kinds of biochar respectively, including poplar biochar (unmodified, FeSO₄ modified, CaCO₃+FeSO₄ modified, CaO+FeSO₄ modified) and bamboo biochar (unmodified, FeSO₄ modified, CaCO₃+FeSO₄ modified, CaO+FeSO₄ modified). First, the removal efficiency of different biochar on Pb(Ⅱ) in groundwater was evaluated through batch experiments. Then, the fixation mechanism of Pb(Ⅱ) in groundwater was explored by means of scanning electron microscopy (SEM) and X-ray absorption near-edge structure spectroscopy (XANES). The results show that the removal efficiency of Pb(Ⅱ) by calcium-iron (CaCO₃+FeSO₄, CaO+FeSO₄) modified biochars were significantly higher than those by iron (FeSO₄) modified biochar. In addition, the removal efficiency of Pb(Ⅱ) by calcium-iron modified biochar with CaO as the calcium source were all greater than 99%. While the removal efficiency of Pb(Ⅱ) by calcium-iron modified poplar biochar and calcium-iron modified bamboo biochar with CaCO₃ as the calcium source were 58% and 37% respectively. The removal efficiency of modified biochar on Pb(Ⅱ) from high to low was in the order of CaO+FeSO4 modification, CaCO₃+FeSO₄ modification, and FeSO₄ modification. The surfaces of calcium-iron modified biochar were porous and rough, which was beneficial for the attachment of Pb(Ⅱ) precipitation substances. Through the linear fitting of XANES of Pb(Ⅱ), the stable Pb(Ⅱ) components on the surface of calcium-iron modified biochar, such as basic lead carbonate and lead chlorophosphate, accounted for a higher proportion compared with other types of biochar. Among them, the proportions of basic lead carbonate and lead chlorophosphate on calcium-iron modified poplar biochar were 28% and 34% respectively, and those on calcium-iron modified bamboo biochar were 28% and 30% respectively. The formation of lead precipitates on the surface of biochar may be one of the main pathways for Pb(Ⅱ) removal.

The purpose of gravity topographic correction   is to eliminate the influence of terrain quality  on  observed gravity, including traditional topographic correction and intermediate layer correction,which  is the most important part of  external correction of gravity exploration, and  also the key factor affecting the accuracy of gravity exploration. For a long time, researchers have carried out a lot of research on  calculation models of topographic correction, calculation methods, and  influencing factors of calculation accuracy, but neglected the unification of topographic correction methods in the process of different measurement methods such as land gravity, ship-borne gravity, air-born gravity and well gravity, as well as  the discussion on the variation law and selection principles of different influencing factors. This paper introduces in detail the research progress and prospect of the fundamental theory, the calculation methods, and the influencing factors of topographic correction. Simultaneously, there are some problems in  topographic correction methods, such as the topographic correction methods of different gravity measurement techniques are not uniform, the significance of gravity anomaly is not uniform, and the research degree of influencing factors of topographic correction accuracy is different. According to the basic principle of topographic correction methods with different gravity measurement methods, it is necessary to formulate a unified topographic correction standard for the overall use of gravity data. Through discussing and analyzing the influence of topographic grid spacing, topographic correction radius and stratum density on topographic correction accuracy, it is proposed that   the regular relationship between topographic grid sapcing,topographic correction radius and stratum density  should be studied  to realize the flexible selection of grid spacing and correction radius in practical work and improve the applicability of  topographic correction methods.

Seafloor massive sulfide (SMS) deposits have emerged as a promising potential resource to address the growing global demand for precious metals, including copper, silver, and gold. The detection and assessment of these deposits are significantly challenging due to the rugged seafloor topography and complex depositional and mineralization environments. Particularly, the electrical anisotropy resulting from the orientation of mineral grains and veins poses additional challenges in interpreting electromagnetic detection data. To address these challenges, this study employs the mimetic finite-volume method  along with the backward Euler scheme to discretize the time-domain Maxwell equations. By utilizing the direct method solver PARDISO, we are able to solve the linear equation system, thereby facilitating a three-dimensional anisotropic forward simulation of the SMSs model. The primary objective of this research is to investigate the influence of the mound depositional environment on the transient electromagnetic response through forward simulation. Moreover, we conduct a detailed analysis of the effects stemming from the conductivity anisotropy of both  sedimentary surrounding rocks and SMSs, making comparisons among different electrical anisotropy models. The results demonstrate the significance of both the  sedimentary surrounding rocks anisotropy and the SMSs anisotropy in influencing the transient electromagnetic response. Additionally, our analysis reveals that the electrical anisotropy of the SMSs exerts a more pronounced impact on the electric field compared to the anisotropy of sedimentary surrounding rocks. Furthermore, we observe that horizontal anisotropy demonstrates a greater influence on the electric field than vertical anisotropy, as evidenced by the diverse electrical anisotropy models explored in this study.

The main oil and gas-bearing strata discovered in  Kaiping sag are primarily located in the Paleogene Enping Formation and Wenchang Formation. The depositional environment is mainly  braided river delta plain subfacies, and the microfacies of underwater distributary channel is dominant. Due to the lateral oscillation of multiple river channels, the strata have strong heterogeneity, making stratigraphic correlation extremely difficult. This paper utilizes the powerful data fitting capabilities of machine learning algorithm support vector machine to determine the optimal fusion frequencies and weights for low, medium, and high-frequency data segments. This process yields inversion results with enhanced vertical resolution and detailed lateral seismic characteristics, thereby improving the accuracy of interwell stratigraphic pinchout positions and the description of stratigraphic connectivity. The high-resolution v_P/v_S inversion results demonstrate that this method is capable of identifying reservoirs with a thickness of 6 m. It offers superior vertical and horizontal resolution, which is conducive to stratigraphic correlation within the study area.

The pore structure determines the storage and seepage capacity of the reservoir, and controls the initial production capacity of the oilfield and even the distribution of the remaining oil in the middle and late stages of development. However, at present, the characterization of the pore structure mostly stays in the core scale. To up-scale characterization of pore structure, pore structure types of cores are divided based on pore and throat size, fluid mobility and physical property parameters obtained from high-pressure mercury intrusion, nuclear magnetic resonance, and conventional physical property analysis experiments, and are used as learning supervised samples. LDA (linear discriminant analysis) algorithm is used to excavate log curves sensitive to pore structure features, and a nonlinear log prediction model is established in collaboration with SSOM (supervised self-organizing map) algorithm to evaluate pore structure of  low-permeability sandstones  in the fourth member of J oilfield in Bohai Bay basin. The results show that there are six types of pore structures developed, among which, microfractures are developed in the type Ⅰ pore structure, which is characterized by low porosity and relative high permeability. The type Ⅱ pore structure is mainly developed in fine sandstone and consists of residual intergranular pores and secondary dissolved pores. The type Ⅲ pore structure is mainly composed of secondary dissolution pores and a few residual intergranular pores, which are common in siltstone. The type Ⅳ pore structure is mainly composed of secondary dissolved pores, and pore-filled carbonate cements are commonly observed. The type Ⅴ pore structure is characterized by extensive carbonate cementation, and the pore system is dominated by micropore throats. The volume fraction of argillaceous matrix in type Ⅵ pore structure is high, and the phenomenon of relatively high porosity and low permeability often occurs. The overall accuracy rate of the LDA-SSOM prediction model attains 86.20%. In terms of the accuracy rate in blind tests, which stands at 82.67%, it outperforms prediction models like LDA-BP (back propagation) (77.00%), LDA (65.67%), and SSOM (73.33%). Moreover, it is capable of fulfilling the objective of escalating the research scale regarding pore structure.

Fracture-cavity reservoirs of Ordovician carbonate rock in Tahe oilfield have various types and complex structures. Acoustic remote detection technology can detect geological anomalies in the range of tens of meters outside the well, and has broad application prospects in the evaluation of fracture-cavity reservoirs. Firstly, the staggered grid finite difference method with perfectly matched layer (PML) absorption boundary conditions is used to simulate the acoustic remote detection logging response of fracture-cavity reservoirs in Tahe oilfield. Then, through the simplified modeling of fracture-cavity spatial distribution, the fracture distribution model with different lengths, openings and angles of  fractures passing through and beside the well and the fracture-cavity reservoir model with the changes of cave, hole size, number and distance beside the well are established. Then the wave field is simulated by finite difference, the wave field characteristics of cracks, caves and dissolution holes are analyzed, and the imaging results of cracks, caves and dissolution holes of acoustic remote detection  wave field are obtained by offset imaging processing method, and the corresponding imaging interpretation model of acoustic remote detection is established. At last, the acoustic remote detection logging data of real drilling are compared with conventional logging, electric imaging logging, seismic profile characteristics, and oil test results. The results show that the acoustic remote detection interpretation model established by this method is effective for the identification and evaluation of carbonate fracture-cavity reservoirs.

Aiming at target tracking and trajectory drawing of ships in satellite remote sensing images, a method combining the global attention mechanism (GAM) module improved YOLO (you only look once) v8 algorithm (GAM-YOLOv8) and the DeepSORT algorithm is proposed. The GAM module is added to the YOLOv8 network structure to enhance the model's ability to extract satellite remote sensing image features and improve the accuracy and stability of ship target tracking. The data enhancement technology based on the RGB (red, green, blue)-HSV (hue, saturation, value) fusion color space conversion convolution module is implemented to expand the data set, helping the model capture more dimensional feature information and further improve the recognition accuracy. The DeepSORT algorithm is used to enhance the stability and accuracy of the tracking process by combining the target's feature appearance and motion information, thereby effectively reducing identity switching and target loss. Experimental results show that the proposed method of combining GAM-YOLOv8 with DeepSORT shows significant performance improvement in remote sensing image ship target detection and tracking tasks compared with the original YOLOv8 model. The accuracy, recall rate, and average precision are increased by 7.6%, 7.9%, and 6.0%, respectively. Meanwhile, the frame rate, multi-target tracking accuracy, and multi-target tracking precision are improved by 17.7%, 6.9%, and 1.9%, respectively, and the number of identity switches is decreased by 10.0%.

The prediction and evaluation of deep-sea polymetallic nodules have entered into the data science paradigm, and the deep mining and fusion of big data for ore prospecting and ore indication are seriously needed. Through analyzing the research progress of  deep-sea polymetallic nodules evaluation, and discussing the application of big data approaches in mineral resources evaluation, the big data mining and fusion techniques towards resources evaluation of  polymetallic nodules are explored, in which, the major research contents and methods like the knowledge pedigree analysis for polymetallic nodules resources, the metallogenic characteristics mining methods based on data science, the fusion and integration methods based on spatial decision-making model with big data, the comparison and verification of quantitative prediction and evaluation on polymetallic nodules resource, are proposed. It creatively analyzes  conventional/unconventional resources evaluating data and its correlation with ore deposits, and establishes the spatial decision-making model with geological constraint and big data. On this basis,  feature extraction and fusion of the information from multi-source heterogeneous data are achieved to supply the technology solution based on big data for deep-sea mineral resources evaluation. The research on big data mining and fusion techniques could improve the accuracy and efficiency of polymetallic nodules resources evaluating, and has important theoretical value and practical significance to the efficient use of deep-sea resource-environmental data, the exploration and evaluation of new polymetallic nodules mining area, and the prediction and evaluation of other deep-sea minerals.