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

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

This paper briefly reviewed the history of the discovery and research of dinosaur eggs in Laiyang, Shandong Province, China. Combining with the new discoveries in the Laiyang basin in recent years, the composition of the Laiyang dinosaur egg fauna was revised from 4 oofamilies, 5 oogenera and 11 oospecies to 6 oofamilies and progress on the dinosaur eggs, 10 oogenera and 12 oospecies, 1 oofamily indet. and 1 doubtful oospecies. Compared assemblages with other dinosaur egg faunas in China, the Laiyang dinosaur egg fauna is a typical representative of the Late Cretaceous dinosaur egg fauna with diverse egg types and distinctive assemblage characteristics. At the same time, this combination also well reflects the high diversity of dinosaurs in the Wangshi Group of the Jiaolai basin during the Late Cretaceous. Further study on it will provide detailed paleontological evidence for further discussion on the paleogeography and paleoenvironment of Laiyang area in the Late Cretaceous.

Surface nuclear magnetic resonance (SNMR) emerges as a non-invasive geophysical method with widespread applications in the qualitative and quantitative detection of groundwater. Its utility extends to resource exploration, geological disaster warning, and environmental monitoring. However, the practical implementation of this method encounters challenges as weak SNMR signals often contend with the pervasive noise in complex environments, hampering effective signal acquisition. In response to this issue, we propose a novel SNMR data noise suppression technique based on a differential structure. This method involves the strategic placement of two receiving coils equidistantly above and below the transmitting coil. This configuration can cancel out a significant portion of ambient noise and mitigates the effects of transceiver coil coupling in real time. Numerical experiments verify that the new method can achieve noise suppression and the reliable acquisition of free induction decay (FID) signals.

Geomagnetically induced currents (GIC) are currents induced in conductive materials on the Earth’s surface due to Earth’s magnetic field variations. GICs have the potential to cause severe damage to manufactured infrastructure, including power grids, oil and gas pipelines, and high-speed railways, resulting in adverse consequences such as power system failures, communication disruptions, and damage to electronic equipment, ultimately affecting the stability and functionality of these systems. The significance of studying GIC lies in understanding their generation mechanisms and influencing factors, thereby providing a scientific foundation for developing effective prevention and mitigation strategies. Based on an in-depth review of the progress in GIC research, this paper elaborates on the mechanisms of GIC generation and the influencing factors, encompassing the impacts of space weather, Earth’s environmental conditions, and the power system on GIC. It provides an overview of the current state of GIC research, offering integrated assessments from space physics, geophysics, and electrical engineering. Furthermore, the paper provides a detailed description of the steps involved in estimating GIC, including using geomagnetic field data and modeling, along with calculating electric fields and GIC within conductors. It emphasizes analyzing how various geophysical parameters affect GIC estimates and their interrelationships. In conclusion, the paper discusses the challenges in GIC research, highlights the potential contributions of geophysics in addressing related issues, and provides a perspective on the future of GIC research.

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

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

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

As one of the important non-metallic strategic mineral resources, the metallogenic regularity, ore prospecting and exploration of fluorite are widely investigated byeconomic geologists. The Xingguo-Ningdu metallogenic belt in southern Jiangxi Province, located at the intersection of the NE-trending Wuyishan metallogenic belt and EW-trending Nanling metallogenic belt, develops a series of fluorite deposits. Previous studies have primarily attributed the deposits to fault control, but the quantitative characterization of the coupling relationship between fractures and the spatial distribution of the fluorite deposits is seldom reported. Based on fractal theory, this paper aims to describe the fractal textural characteristics between fractures and fluorite deposits in Xingguo-Ningdu metallogenic belt to identify key ore-forming and prospecting areas of fluorite. The results show that: 1) The NE-NNE-trending fracture capacity dimension, information dimension and correlation dimension of the study area are 1.609 0, 1.608 9, and 1.594 7, respectively, indicating superior metallogenic geological conditions and a strong relationship between NE-NNE faults and fluorite mineralization in the study area; 2) The capacity dimension, information dimension and correlation dimension of fluorite deposits are 0.937 9, 0.921 5 and 0.926  2, respectively. When there is a statistical center deposit, the fractal dimension of the number fractal distribution of fluorite deposits is 0.784 1, and the fractal dimension of the density fractal distribution is 0.784. When there is no statistical center deposit, the fractal dimension of the number fractal distribution of fluorite deposits is 1.129 6, and the fractal dimension of the density fractal distribution is 1.130; 3) According to the coupling characteristics of the fractal dimension value of fracture and the spatial distribution of fluorite deposits in the study area, as well as the fractal characteristics of the number and density of fluorite deposits, the three-level favorable metallogenic areas are comprehensively delineated, in which the I-level favorable metallogenic area is the area with the best metallogenic condition and the largest metallogenic potential; 4) According to the coupling characteristics of fracture dimension value and spatial distribution of deposits, the number and density fractal characteristics of deposits, the key ore forming and prospecting areas in the fluorite ore concentration area or metallogenic belt controlled by fracture system can be quickly and effectively delineated, which is expected to provide important reference information for the resource exploration of fluorite.

The Benxi area of Liaoning Province is located in the northeastern part of the eastern North China craton, where Neoarchean plutonic intrusive rocks and metamorphic supracrustal rocks are widely developed, but no kaligranites have been reported. The formation process of kaligranites is an important symbol of the maturation and stability of the early continental crust. The discovery of kaligranites is significant for the systematic study of the formation and evolution of the early continental crust in the North China craton. In this paper, the petrology, diagenetic age, and petrogeochemistry of kaligranites in Majiagou, Benxi area are studied, and the petrogenesis and tectonic setting of formation are discussed. Majiagou pluton is a gneissic medium-fine-grained biotite monzogranite. The  zircon U-Pb dating data show that the 207 Pb/ 206 Pb weighted average age is (2 490±21) Ma, suggesting the kaligranites formed in the Late Neoarchean. The granite is weakly peraluminous and high potassium calc alkaline kaligranite. The high field strength elements La, Zr, Th and large ion lithophile elements K, Nd are enriched, while high field elements P, strength elements Nb and large ion lithophile elements Sr, Ti are depleted. The REE partition curve is rightward with negative Eu anomalies, indicating S-type granite. The magma originated from the crust and the product of partial melting of metamorphic mudstone, which formed in an extensional environment after collisional orogenesis at active continental margins. It represents the last magmatic activity before the formation of the consolidated basement of the Archean craton in North China, and marks the completion of the collage of micro-blocks in Benxi area in the Late Neoarchean, and together with other regions, forming a stable North China Archean craton.

The granite gneiss in the Xinyi area is located on the western margin of the Sulu orogenic belt. This paper discusses its petrogenesis and tectonic environment by examining petrography, rock geochemistry, and zircon U-Pb isotopic chronology of the granite gneiss. It also reveals the repercussions of the breakup event of the Rodinia supercontinent in this area. The findings indicate that the granite gneiss in the study area belongs to the meta-aluminous-weak peraluminous A-type granite, characterized by high SiO2 content, rich alkali, low CaO and Al2O3 contents, and a right-dipping seagull-type rare earth distribution pattern. It is enriched in Rb, Zr, Hf elements, while being severely depleted in Sr, Eu, Nb, Ta elements. The age of the granite gneiss is 746.0-742.5 Ma. The granite gneiss in the Xinyi area originated from the partial melting of lower crustal material and a small amount of mantle-derived material. In the process of magma evolution, it underwent the separation and crystallization of potassium feldspar and plagioclase, and eventually formed through ultra-high pressure metamorphism. The granite gneiss in the Xinyi area was formed in a post-collisional extensional environment in the Neoproterozoic, marking the initial response to the Rodinia supercontinent breakup event in study area of the Sulu orogenic belt.

The characteristics of different stages of petroliferous basins are of great significance for the restoration of basin evolution and the evaluation of hydrocarbon generation, storage and transportation conditions. In this study, we systematically reviewed previous studies on the nature and evolution of the Cenozoic western Qaidam basin. Based on the interpretation of seismic profiles combining with the basin tectonic geometry, sedimentation rate, sedimentation phase, sedimentation cycle, sedimentation center migration and unconformity contact relationship within the basin, we concluded that the Cenozoic western Qaidam basin, as a large intracontinental depression in a compressional environment, has an asymmetric geometric configuration in the seismic section, high deposition rate but slightly lower than the western typical foreland basin, and migration of sediment centers due to strong shortening under overcompensation, with obvious reverse cycling sedimentary-tectonic development. Importantly, the deposition of Shizigou Formation is considered as the sedimentary boundary of the Cenozoic western Qaidam basin, showing that in the early stage, fine-grained far-source sediments were developed, belonging to a depression basin; While, in the later period, the sedimentation rate increased significantly, and the coarse-grained deposition developed, which had the characteristics of atypical foreland basin. The fact significantly suggests that it’s controlled by the combination of tectonic activity of the surrounding mountains and overcompensation state of the basin.

A large area of Permian basalt is exposed near Shawan District, Leshan City, which is an important part of Emeishan large igneous province. Petrological and geochemical analysis show that the basalts are mainly dense massive pyroxene basalts, oblique porphyry basalts and trachyte basalts. The major elements indicate  that basalts belong to high-titanium tholeiite series. The normalized rare earth element pattern of chondrites for basalts in the Shawan area exhibits right-dipping patterns with LREE enrichment and a high degree of fractionation of light and heavy rare earth elements. The normalized trace element distribution map of the primordial mantle shows that they are enriched in large ion lithophile elements (LILE) such as Th、 U etc, but depleted in trace elements related to fluids (Sr and P) with negative Eu anomalies. It is similar to the ocean island basalts (OIB) and high-titanium basalts that erupted in the late period near Binchuan, Yunnan, suggesting that the basalts around Emeishan were formed in an intraplate rift environment induced by a mantle plume. The magma originated from the low-degree partial melting of the garnet peridotite and the separation and crystallization of plagioclase, and weak crustal contamination occurred during the ascent. The geochemical comparison between the basalts in the intermediate zone and the basalts in the inner zone of the large igneous province reveals that the basalts in Shawan area are the product of late magmatism in the large igneous province, and the main body is characterized by the edge of the mantle plume itself.

Baolingshan tunnel is a key and difficult control engineering in the first section of a certain railway. The depth of survey Borehole DZ-06 is 2 118.00 m, which is the deepest survey borehole in this railway. Appropriate cores were selected at the depths of 2 072.53 m and 2 084.27 m, and in-situ stress test was carried out by anelastic strain recovery method（ASR）. The results show that in the depth range of 2 072.53-2 084.27 m, the average values of the maximum principal stress, intermediate principal stress and minimum principal stress obtained from the two measuring points of ASR method are 59.70, 54.03 and 30.74 MPa respectively. The maximum principal stress is nearly horizontal and the direction is close to SN direction, indicating that the area is dominated by horizontal tectonic stress. The average value of the maximum principal stress test result of ASR method is in good agreement with the regression value from the hydraulic fracturing method test, the consistency of the minimum principal stress test value and the regression value of the hydraulic fracturing method test result is in a reasonable range, and the horizontal principal stress direction test results from the two methods are basically consistent.

Soft soil has the characteristics of poor permeability and low bearing capacity. The treatment of soft soil foundation is always a major problem in geotechnical engineering. With the characteristics of free power in drainage, the siphon drainage method can be applied in soft ground the treatment to improve the properties of the soil. Based on the discretized Theis well flow model and the nonlinear layered summation method of settlement, this paper constructs a water level and settlement calculation model considering the changes in permeability coefficient and compressive modulus by settlement with porosity as the core for the unique fixed-deck precipitation model of the siphon drainage method. The effect of the siphon drainage method in soft foundation treatment is analyzed from the aspects of soil permeability coefficient, drainage board spacing, and site size. The results mainly focus on the following three aspects. First, the calculation outcomes are compared with numerical simulation results and the reliability of the calculation model is verified. And the siphon drainage method can perform well in drainage and consolidation for soils of different permeability coefficients in Zhejiang coastal areas. Second, adjusting the spacing of drainage plates can significantly control the drainage consolidation time and the groundwater level. Third, the additional stress caused by drainage will extend into the soil as the site area increases, and for a 50 m×50 m site, the effective influence depth can reach 27.31 m below the surface, which is far beyond the limit of siphon lift. Therefore, the siphon drainage method will get a better effect in practical large-area soft soil foundation treatment.

In order to grasp the comprehensive influence law of shield tunneling parameters and geological conditions on surface subsidence between shield intervals in sandy gravel stratum, a shield interval of Chengdu Metro is chosen as a case study, combined with the relationship between the surface subsidence and tunneling parameters of the our study team in the early stage, the total thrust，cutter head speed，screw machine speed，overlying soil thickness，groundwater level and gravel stratum thickness are determined as clustering indexes. The K-means algorithm is applied to cluster the actual monitoring data of each parameter index, and the influence of each index on the surface subsidence is analyzed comprehensively. The research results show that: 1) According to the results of K-means clustering, the monitoring points, corresponding to construction sections, are divided into three risk levels of surface subsidence, 1－3 is strong dangerous (Grade Ⅰ), 7－13, 16－19, 25－34 are weak dangerous (Grade Ⅱ), 4－6, 14－15, 20－24 are safe (Grade Ⅲ). 2) According to the clustering results, there is a positive and negative correlation between tunneling parameters, stratum structure and surface subsidence in a specific range. 3) Through an analysis of the relationship between geological structure, tunneling parameters and surface settlement, it is determined that when the overlying soil layer is thick, the groundwater level is low, and the gravel layer is thick, the control range of excavation parameters is a total thrust of 29 034.00-31 181.95 kN, cutterhead rotation speed of 1.25-1.32 r/min, and screw conveyor rotation speed of 6.13-6.98 r/min. When the overlying soil layer is thin, the groundwater level is low, and the gravel layer is thin, the control range of excavation parameters is a total thrust of 34 419.89-36 867.28 kN, cutterhead rotation speed of 1.44-1.45 r/min, and screw conveyor rotation speed of 5.74-6.99 r/min.

To describe the creep characteristics of rocks under hydration freeze-thaw coupling conditions, uniaxial compression creep and nuclear magnetic resonance tests were conducted on marble under acidic, alkaline, neutral solutions and different freeze-thaw cycle conditions. T2 spectrum distribution and creep test results were analyzed, and coupled damage evolution was carried out. Finally, a new creep damage constitutive model considering the coupling of hydration freeze-thaw and stress was obtained. The results show that: 1) The T2 spectrum of marble exhibits three peaks, and pore in the rock is mainly composed of large size pores. 2) The freeze-thaw cycle promotes the development of pores in marble, and the influence degree of different solution environments on pore development from high to lower is acidic, alkaline, and neutral. 3) The hydration freeze-thaw and load damage variables were constructed to establish a new creep damage constitutive model of marble under the coupling conditions of hydration freeze-thaw. 4) The average R2 of 50 freeze-thaw cycles of three different solutions of marble simulated by a new model is 0.985 4, while the average R2 of the basic model is only 0.919 4.

Disasters induced by rock creep in engineering are common, and soft rock creep is also more common in actual engineering. In order to explore the soft rock creep characteristics and accurately predict the soft rock creep deformation. In this study, firstly, a one-dimensional secondary consolidation creep test was carried out on the soft mudstone in Lund area of Guyuan City, Ningxia, and the creep characteristics of soft mudstone under the one-dimensional secondary consolidation creep test were analyzed. Secondly, the concept of fractional order theory was introduced to derive the fractional order Burgers model constitutive equation which can describe the nonlinear creep characteristics. Finally, the lsqcurvefit algorithm in Matlab was used to numerically solve the one-dimensional secondary consolidation creep test data of soft mudstone, and the effect of fractional order number on the one-dimensional secondary consolidation creep curve of soft mudstone was analyzed. One-dimensional secondary consolidation creep test shows that the creep mechanism of soft mudstone conforms to the three stages of transient deformation, consolidation deformation, and stable deformation in consolidation creep, and shows obvious nonlinear characteristics. And the undisturbed sample, remodeled sample in the consolidation process produced a large degree of secondary consolidation creep, the maximum deformation can account for 59% of the total deformation. Numerical simulation results show that the fractional order Burgers model can better describe the nonlinear characteristics of the sub-consolidation creep; Model fractional order γ has a strong sensitivity to reflect the elasticity of the fitted curve and the nonlinear viscoelasticity after the stage, and fractional order  β  sensitivity is poorer than the viscoelasticity stage of the creep tendency to make a subtle response.

In order to achieve the goal of restoring water to the river as long as possible and to restore the basic ecological functions, a SWAT (soil and water assessment tool) hydrological model for the Fuyang River basin was established based on the current status of water conservation measures and water transfer projects. The different ecological water replenishment scenarios were designed, the variation of runoff volume and the restoration of the annual number of days with water were analyzed for different scenarios. Ecological restoration effects were analyzed based on the ecological base flow standard. The results show that the river ecological restoration effect is better in the water conservation scenario and the water transfer scenario in the Handan section of Fuyang River basin, and 184 days of water restoration from May to October can be achieved through the upstream water conservation measures and the scenario of 1.00×108 m3/a of supplemental annual water transfer, and the restored runoff volume of 3 486.7×104 m3/a, the water replenishment can reach the ecological baseflow standard and guarantee the basic ecological function of the river. The Xingtai section in the lower reaches of Fuyang River has less restored runoff under water-saving and water transfer scenarios, so the number of days with water in the river does not meet the standard, and it needs to supplement the external water transfer volume of 1.50×108 m3/a under the upstream water conservation condition to achieve the restoration of the annual number of days with water is 304 days and the restored runoff volume of 1 906.5×104 m3/a, and Xingtai section under the scenario of achieving the target of restoring water. The ecological replenishment scheme of increasing water transfer for single point replenishment in different periods needs to be considered as it cannot reach the ecological base flow standard of the river.

Natural processes and human factors can activate and migrate the selenium into and out of the soil. Finding out the provenance and migration mechanism of selenium in soil is of great scientific and practical significance for selenium-rich land management and selenium-rich industrial development. The lithosphere and dry and wet deposition of atmosphere are the most basic sources of soil selenium. Surface runoff, groundwater lixiviation, crop harvesting and volatilization of plants and microorganisms are the main ways of selenium loss. The migration of selenium in soil can be attributed to hydrodynamic migration mechanism, solid phase adsorption mechanism and absorption, degradation and volatilization mechanisms. Soil composition and physicochemical conditions affect the migration and redistribution of selenium in soil by changing the process of the above mechanism. Climate, topography and agricultural activities indirectly affect the migration and redistribution of selenium in soil by changing soil composition and physicochemical conditions. Geological background, climatic conditions, and topographic factors are very important for the distribution of selenium on a regional scale (such as continents, countries and provinces), while on a local scale (such as counties, townships and farmland), the impact of human activities, especially agricultural farming, is more significant. Based on the behavioral characteristics of selenium in soil, a series of selenium resource management strategies have been developed:1) Biofortification and remediation regulate selenium distribution and bioavailability in soil through animal and plant transformation, which is considered to be an ecologically Selenium management solution. 2) The irrigation mode adjusts the physical and chemical conditions of the soil by changing the hydrodynamic conditions, thereby changing the solid phase adsorption of the soil and the transformation of animals and plants. The water management mode combining flood irrigation and aerobic irrigation is believed to improve the availability of soil selenium. 3) Agronomic measures such as applying selenium fertilizer, phosphate fertilizer, sulfur fertilizer and liming adjust the distribution and availability of soil selenium by directly changing soil composition and physical and chemical conditions. This is a traditional selenium-rich agronomic measure, but it may also produce certain ecological effects. risk.

Analytic signal is a common tool for magnetic data processing and interpretation. Based on the relationship of different order analytic signals and their vertical derivative, this paper introduced a magnetic source variable depth imaging function with a depth scaled factor. The new method can be used for determining the position of filed source by using the maximum value of depth imaging, and estimating structural index on basis of the inverted depth and imaging maximum value. In addition, we can use the imaging results with different depth scaled factors and different orders to improve the reliability and usability of the new method. Model tests and applications indicate that the new method can    abtain  stronger computational  stability, higher spatial imaging resolution and more accurate field source parameter inversion results using lower-order derivatives, compared with the DEXP (depth from extreme points) methods of analytic signal ratio and local wavenumber.

This study investigates the impact of different power supply direction excitation on the exploration effect of the three-dimensional (3D) induced polarization (IP) method, for a central gradient array of  multi-group power supply pole distance combinations. We employ the 3D unstructured finite element numerical simulation for direct current  point power supply and the incomplete Gauss-Newton 3D inversion. The goal is to provide a basis for the rational selection of power supply directions for 3D IP measurements. First, we design various 3D geoelectric models and conduct forward and inverse modeling for three power supply modes: transverse, longitudinal, and transverse/longitudinal bidirectional combinations. Then we perform 3D inversion on IP measured data obtained in a mining area under these three power supply modes. Finally, the 3D inversion results of theoretical model synthesis data and measured data and the existing geological data of the mining area are synthetically analyzed. We find that 3D inversion results for IP data under transverse, longitudinal, and transverse/longitudinal bidirectional combination power supply modes can effectively depict the lithological and structural distribution characteristics. In terms of revealing local anomaly information, the bidirectional combined power supply IP data yields the most abundant and complete information. By contrast, the inversion results of single-directional power supply IP data may lack some effective anomaly information, presenting incomplete anomaly details.

The traditional single-set one-dimensional(1D) inversion is the most widely used technique for the processing and interpretation of transient electromagnetic data in coal mines. However, this approach becomes inadequate when the stratum exhibits a significant dip, as the single-set horizontal layered model fails to accurately represent the electrical distribution characteristics. To address this limitation, we employ the weighted laterally-constrained inversion method to constrain the layer interface depth and incorporate the difference in geoelectric parameters between adjacent measurement points into the objective function as a constraint term. We describe the transient electromagnetic 1D forward and inversion theory, and detail the inversion method with weighted lateral constraints. The influence of the weighting factor on inversion results is analyzed using the H-type and K-type models with varying inclinations. Compared with  the traditional 1D inversion, the weighted laterally-constrained inversion is a pseudo-2D inversion method by establishing   layer parameters and  depth-weighted constraint equations  and synthesizing total inversion equations. The obtained resistivity profiles exhibit strong agreement with actual models and demonstrate good longitudinal and transverse continuity. The employed method effectively restores the electrical distribution of inclined strata, and the inversion results match the actual geological data.

In the context of seismic data processing, the presence of multiples poses inherent challenges to the imaging and interpretation of seismic data. The effective suppression of these multiples stands as a key issue in seismic exploration. Leveraging its high efficiency, the parabolic Radon transform emerges as a widely used technique for multiple suppression. However, in field seismic data acqisition, due to the limited offset, energy diffusion and illusions reduce the effect of multiple suppression in the Radon domain. In response to this challenge, we propose a L1/2-regularized high-resolution parabolic Radon transform with sparse inversion, where the inverse problem is solved by  generalized iterated shrinkage algorithm (GISA). The L1/2 regularization chosen for its robust sparse constraint capabilities plays an important role in enhancing the solution sparsity and improving the signal-noise separation. Compared with the least square inversion and the sparse inversion method based on L1 regularization, the L1/2-regularized sparse inversion of using the high-resolution parabolic Radon transform can suppress multiples effectively and ensure the consistency between the reconstructed data and the original data.

The traveltime formula based on Taylor expansion is a common method to calculate P-wave traveltime. The Taylor expansion is accurate only near the calculation point, and the inaccuracy of the traveltime approximation is further magnified in the medium of   transverse isotropy  with vertical  symmetry axis   (VTI). An improved method for calculating P-wave traveltime is presented in this paper. This method utilizes the 8th-order offset-traveltime equation based on the Taylor expansion, and the coefficient matching method is used to determine the coefficients of the series expansion. Then the integration processing is used to optimize the parameters. Finally, the 4th-order P-wave traveltime calculation method is formed  based on  coefficient matching and parameter integration. The test results for horizontal layered VTI medium models show that the proposed method has relatively small numerical errors and relatively good performance at the far offset. The experimental results for 3D VSP data show that after parameter adjustment, the method effectively analyzes the data, exhibiting stable performance at middle offsets and a certain advantage at far offsets. 

Lithology recognition plays an important role in reservoir logging evaluation, influencing the accuracy of critical parameters such as development degree and porosity. In Huizhou  26-6 well block within the Pearl River Mouth basin in the northern South China Sea, the lithology of igneous rocks is intricate, with widespread alteration significantly impacting conventional logging data. As a result, the conventional lithology identification faces difficulty in satisfying the exploration needs. To enhance the accuracy of identifying altered igneous rocks, we integrate conventional logging and element cutting logging to establish lithology identification methods through diverse machine learning algorithms. A comparative analysis leads to a comprehensive identification method of discerning altered igneous rocks. Initially, a core element data-based correction method for element cutting logging is established to obtain reliable data. Subsequently, the k-nearest neighbor (KNN) method and the support vector machine (SVM) method are employed to identify the lithology of six igneous rocks in the study area—diorite, tectonic schist, altered diabase, granodiorite, altered granite, and granite.  In the target layer of four wells with rock slice identification data in Huizhou 26-6 well block, data points (145 in total) are extracted according to the corresponding depth, of which 80% are used as training samples and the remaining 20% as test samples. Taking  sample test accuracy and  whole well lithology recognition effect as  evaluation indicators, the results of comparing the two algorithms indicate that the recognition accuracy of KNN and SVM algorithms is both 92.65%, but the whole well recognition effect of KNN algorithm is more in line with the distribution characteristics of stratigraphic lithology, indicating that the comprehensive lithology recognition based on KNN algorithm is more suitable for the study area.