This study investigates the petrography, zircon U--Pb geochronology, and whole-rock geochemical data of the No. 1 intrusion in the Hongqiling nickel deposit, determining its formation age, petrogenesis, and tectonic setting. The Hongqiling ore cluster area hosts over 30 mafic-ultramafic intrusions of varying sizes, whose distribution patterns are distinctly controlled by regional secondary faults, exhibiting an overall bead-like distribution trending northwest. The currently proven nickel resources amount to 220 000 tons, among which the No. 1 intrusion serves as one of the most important ore-forming intrusions in the study area. The intrusion is characterized by low silicon [w(SiO2 ) =43. 62%--43. 01% ], low titanium [w(TiO2 ) = 0. 35%--0. 54% ], high magnesium [w(MgO) = 33. 04%--34. 49% ], and alkali depletion [w(Na2O + K2O) = 0. 96%--1. 03% ], belonging to the subalkaline series. Its m/ f ratio ranges from 5. 39 to 5. 88, classifying it as mafic ultrabasic rock (m / f = 2. 0--6. 5). The chondritenormalized rare earth element distribution pattern of the rock exhibits light rare earth element enrichment, with (La / Yb) N ratios ranging from 1. 60 to 4. 28. The rock samples involved in the study exhibit distinct geochemical enrichment characteristics of large ion lithophile elements (LILEs), specifically manifested by significantly elevated mass fractions of elements such as Ba, Rb, Th, U, and K. In contrast, the high field strength element (HFSE) group, including Nb, Ti, Zr, Hf, and P, generally shows relative depletion. The La / Nb, Th / U, Ce / Pb, and Nb / U ratios of the intrusion indicate crustal contamination of the magma. This is further corroborated by the anomalously high Pb mass fraction, the presence of 2 461. 3 Ma captured zircons, and the characteristics of ( Ta / Th) N and (Th / Yb) N ratios, collectively confirming significant crustal material contamination during magma evolution. Zircon Hf isotope analysis reveals that the olivine pyroxenite exhibits εHf (t) values ranging from 9. 8 to 12. 6, with TDM1 ages of 543--417 Ma, indicating that the magma source of this intrusion was primarily derived from depleted mantle. The U--Pb age of No. 1 intrusion measured in this study is (236 ± 10) Ma, suggesting that its rock-forming and mineralization epoch belongs to the Indosinian period. This study proposes that the fractional crystallization of olivine and orthopyroxene, coupled with crustal contamination, served as the key mechanism driving the magma system to achieve sulfur saturation. The intrusion formed in an extensional setting following the closure of the Paleo--Asian Ocean.

The eastern segment of the Daqingshan area of Inner Mongolia lies within the Paleoproterozoic collisional orogenic belt along the northern margin of the North China Craton (NCC), serving as a key area for studying the early tectonic evolution of the NCC. To constrain the depositional age, provenance, and regional tectonic setting of the medium-low grade metamorphic sedimentary rocks in this region, the Erdaowa Group and Majiadian Group two sets of medium-low grade metamorphic sedimentary sequences within the study area were selected as the research objects. Systematic field geological surveys, petrographic studies, indoor microscopic petrographic identification, and detrital zircon LA--ICP--MS U--Pb geochronological testing and analysis were carried out as comprehensive research work. The results reveal that the metamorphic sedimentary rocks in the region have generally recorded multiple tectono-thermal events: two major magmatic events ( peaking at ~ 2. 40 Ga, and ~2. 14 Ga), two early metamorphic events ( ~ 2. 4 Ga, 2. 30 ~ 2. 10 Ga) and a significant regional metamorphic event between 1. 97 and 1. 86 Ga. Integrated with previous regional research findings, it is inferred that the detrital materials of the Erdaowa Group are mainly derived from the Early Paleoproterozoic arc magmatic rocks and basement rocks of the Ordos Block, while the provenance of the Majiadian Group is dominated by the Archean basement rocks of the Yinshan Block. The constraints from the youngest detrital zircon ages and the subsequent oldest metamorphic zircon ages indicate that the Erdaowa Group and Majiadian Group were deposited nearly synchronously, with the sedimentary age constrained between 2. 09 Ga and 1. 97 Ga, in an active continental margin tectonic setting. The research conclusions reveal that the regional tectonic evolution exhibits distinct phased characteristics: at ~ 1. 97 Ga, the Yinshan Block and the Ordos Block collided and accreted. Subsequently, the tectonic regime transitioned to a post-orogenic extension stage at ~ 1. 86 Ga. The intrusion of mafic dyke swarms at ~ 1. 78 Ga marks the basic completion of the cratonization of the North China Block, which then entered a stable sedimentary stage of cratonic cover. During the orogenic evolution process, the Erdaowa and Majiadian groups were incorporated into different crustal levels of the orogen belt, and experienced varying degrees of metamorphism ranging from amphibolite facies to greenschist facies.

To achieve efficient and accurate measurement of the small volumetric weight of dense massive ores with large mass and irregular shapes, and solve the problems of cumbersome operation, low efficiency and error  propagation in existing measurement methods, a mass-volume conversion method based on hydrostatic principles is proposed in this paper. First, the mass of the sample in air is weighed. Then, a graduated measuring jug filled with water is placed on an electronic balance and tared. The sample is suspended with a thin thread and fully immersed in water without touching the inner wall of the jug, and the stable reading of the balance is divided by the density of water to obtain the sample volume. This converts the ore volume, which is difficult to measure directly, into the mass measurement of the sample in water, and then the ore density is calculated. This method was applied to test the small volumetric weights of multiple altered and mineralized wall-rock samples from the Wudaoyangcha iron deposit in Jiangyuan District of Baishan City, and parallel experiments were carried out using the hydrostatic balance method as a control. The results showed that the small volumetric weights of the samples measured by the mass-volume conversion method were 3. 22 g / cm 3 , 2. 91 g / cm 3 , 2. 91 g / cm 3 and 3. 25 g / cm 3 , which were highly consistent with those obtained by the hydrostatic balance method. The relative standard deviations of volume measurement ranged from 0. 089% to 0. 175% , meeting industry requirements. Moreover, this method features simpler operation and higher efficiency, and has a theoretical advantage in measurement accuracy. Aiming at the problem of reading fluctuation caused by manually suspending the sample in this method, a new-type hydrostatic balance model was designed based on the above principle, which eliminates the random error caused by human operation from the structural perspective. The study indicates that the mass-volume conversion method is suitable for the determination of the small volumetric weights of dense massive ores, which provides a new idea for the measurement of volume and density of irregular ore samples in the laboratory, and the designed new-type hydrostatic balance also provides a practical equipment reference for relevant measurement work.

To clarify the genesis of low-resistivity oil layers and improve the accuracy of oil saturation evaluation in the third member of the Dongying Formation in the deep sag of the Qikou Sag, rock physics experiments, highpressure mercury injection, nuclear magnetic resonance (NMR) logging, and oil-test data were comprehensively integrated to analyze the main controlling factors of low-resistivity oil layers from the perspective of pore structure, and a saturation evaluation method suitable for the study area was established. By comparing reservoir properties, grain size, mineral composition, formation-water salinity, and pore structure between the deep sag and the slope area, the main controlling factors for the formation of low-resistivity oil layers were identified. Combined with highpressure mercury injection experiments and NMR logging data, the effects of pores of different sizes and bound water on reservoir conductivity were analyzed. The results indicate that the reservoirs in the third member of the Dongying Formation in the deep sag of the Qikou Sag are characterized by the development of medium and small pores, especially micro-capillary pores. High bound-water porosity favors the formation of a continuous conductive network and is the main cause of reduced oil-layer resistivity. Compared with the conventional interpretation of lowresistivity genesis based on bound-water saturation, analyzing the controlling effect of bound-water porosity on resistivity is more direct and can more effectively reflect the conductive characteristics and their variation of low-resistivity oil layers. Based on the pore-structure characteristics of the study area, the pore-size classification criteria of the threepore-section saturation model were optimized, and the boundaries of large, medium, and small pores were redefined, thereby improving the applicability of the model to complex low-resistivity reservoirs in the deep sag. The application results show that the average absolute error of oil saturation calculated by the optimized three-pore-section model is 8. 52% , which is significantly lower than that of Archie􀆳s equation (17. 16% ). The results indicate that high bound-water porosity is the main cause of low-resistivity oil layers in the study area, and that the optimized three-pore-section model is applicable to the saturation evaluation of such reservoirs. 

In order to clarify the controlling effect of the vertical segmented growth pattern of faults on the safe deployment of directional wells and accurately predict the safe distance for the production of remaining oil near faults, this study takes the F275 fault as the research object in the Xingbei area of the Songliao Basin, which is rich in oil and gas resources, has great development potential and features complex fault development. Based on vertical segmented growth mechanism of faults, various technical methods are comprehensively adopted, including fine structural interpretation of 3D seismic data, systematic observation of drilling cores, identification and homing of logging fault points, fine correlation of sublayers at the single sand body level, geological verification of field outcrops and theoretical analysis of fault-related folds. Vertical segmented growth evolution model and quantitative discrimination method of faults under extensional background in Songliao Basin are systematically established. Constraint mechanism of vertical segmented growth of faults on trajectory design and well deployment of directional wells is deeply analyzed. Results show that vertical growth process of faults in Songliao Basin can be divided into three evolution stages: isolated fault propagation, vertical segmented independent growth of faults, and hard connection and penetration of segmented faults. Based on characteristics of throw-burial depth curve, response characteristics of seismic profiles, evidence of logging fault points and fine correlation of sublayers, a comprehensive discrimination method for vertical segmented growth of faults suitable for clastic strata in Songliao Basin is established, which can effectively identify vertical segment interfaces and segmented overlap areas. Vertical segmented growth of faults is the core geological cause for widespread phenomenon of “one well with multiple faults” in vertical wells and directional wells during oilfield development. According to comprehensive calculation of fault damage zone width and overlap distance of segmented faults, safe deployment distance of directional wells in footwall of F275 fault is 69. 02 m. This result can provide a quantitative basis for the efficient tapping of remaining oil near faults, the safety of drilling engineering, and the reduction of the incidence of accidents such as lost circulation and well collapse.

This study aims to elucidate the key geological controls on deep coalbed methane (CBM) enrichment in the districts 3 and 4 of the Fukang mining area, Xinjiang, and to reveal the patterns governing gas reservoir formation and distribution. The findings are intended to provide a scientific basis for the exploration planning and prediction of favorable zones for deep CBM resources in this region. By integrating basin modeling techniques, the burial and thermal evolution histories (based on vitrinite reflectance, Ro) of the coal seams in the study area were reconstructed. Laboratory analyses of coal samples were conducted to determine key reservoir properties, including porosity and permeability. The data were combined with well-log interpretations, gas volume fraction measurements, and coal seam thickness evaluations to investigate the controlling influences of thermal maturity, tectonic uplift history, preservation conditions, and reservoir characteristics on CBM enrichment. The results indicate that deep CBM enrichment is primarily controlled by a relatively high degree of thermal evolution, with Ro values predominantly ranging between 0. 6% and 0. 7% , which provides a substantial material foundation for gas generation. The rate of late-stage tectonic uplift significantly affects preservation conditions, areas with uplift rates below 8 m / Ma are conducive to maintaining formation pressure and promoting gas adsorption and retention. The reservoirs generally exhibit low permeability, with values mostly below 0. 10 × 10 - 3μm 2 in the third district and ranging from 0. 09 × 10 - 3 to 12. 33 × 10 - 3μm 2 in the fourth district. Deep in-situ stress compression is identified as the main cause of permeability reduction. These reservoir properties primarily constrain productivity rather than significantly influencing gas content. A strong positive correlation is observed between coal seam thickness and gas volume fraction, indicating that thicker coal seams represent favorable zones for CBM enrichment. In summary, deep CBM enrichment in the third and fourth districts of the Fukang mining area follows a core geological model characterized by “substantial hydrocarbon generation, gradual uplift, and effective preservation. ” Sufficient thermal maturity forms the foundation for enrichment, slow late-stage tectonic uplift is critical for preservation, and competent roof sealing combined with structurally stable zones provides essential safeguards for gas accumulation. The coupled interaction of the three key factors exerts a joint control over the enrichment and distribution of deep coalbed methane.

Taking the mudstone-shales of the Lower Cretaceqous Nantun Formation in the Wuerxun --Beier Depression of the Hailar Basin as the subject of study, this research integrates data from core observation, thin-section analysis, mineral composition analysis, scanning electron microscopy, nitrogen adsorption, high-pressure mercury injection, and nuclear magnetic resonance ( NMR), and based on a detailed lithofacies classification of the mudstone-shales, we systematically compared the reservoir properties, pore structures, and oil-bearing potential of different lithofacies. This study identified the favorable lithofacies for shale oil and the key factors controlling their enrichment. The results indicate that the Nantun Formation mudstone-shales can be classified into six lithofacies: high-organic-matter felsic laminated mudstones, high-organic-matter felsic massive mudstones, medium-organic-matter felsic massive mudstones, medium-organic-matter clayey laminated mudstones, medium-organic-matter clayey massive mudstones, and low-organic-matter felsic massive mudstones. The porosity of the samples ranged from 0. 60% to 6. 80%, and the permeability ranged from 0. 000 1 × 10 - 3 to 0. 093 4 × 10 - 3 μm 2 . The correlation between porosity and permeability was weak, indicating that microfractures and pore throat connectivity play a significant role in controlling permeability. Clay-rich rocks have a higher specific surface area and well-developed micro- and mesopores, resulting in strong adsorption. Crude oil is primarily present in an adsorbed state and exhibits poor mobility. Felsic laminated mudstones with high organic matter content have moderate specific surface areas and well-developed pore-fracture interconnected systems. Two-dimensional NMR analysis indicates that their total oil content reaches 75. 00%, with free oil accounting for 42. 20%, making them the most favorable shale oil lithofacies type in the study area. The accumulation of shale oil in the Nantun Formation is primarily controlled by three factors: high TOC provides an ample source of hydrocarbon-generating material, the feldspar-quartz mineral matrix facilitates pore preservation and reduces adsorption constraints and the laminated structure promotes the development of bedding planes and microfractures while improving connectivity. The synergistic interaction of these three factors collectively enhances the accumulation and mobility of shale oil.

Continental rift basins are often characterized by complex uplift-sag structures and intricate tectonic palaeogeomorphology. To overcome the limitations of traditional palaeogeomorphology restoration methods, which focus only on sag sedimentary areas and neglect uplift source regions, this study takes the Lishu Fault Depression in the Songliao Basin as an example, integrating 3D seismic, well logging, and mud logging data to develop a comprehensive structural palaeogeomorphology restoration method spanning from uplift denudation areas to sag sedimentary basins. The proposed method combines multiple approaches, including the porosity / vitrinite reflectance ( Ro ) method, seismic stratigraphy trend analysis, buried hill structural deformation trend compensation, sedimentary volume balance principles, lithological decompaction, and cross-validation among these techniques, advancing palaeogeomorphological restoration from qualitative description to quantitative reconstruction and enhancing both accuracy and reliability. This approach enables a complete characterization of the source-channel-sink system, clarifying the scale and lithology of source areas over time, the type and distribution of transport pathways, and the pattern and sedimentary response of depositional areas, demonstrating the direct control of palaeogeomorphology on the source-sink dynamics. It establishes that the area, slope, and internal structure of catchment systems in uplift source regions are directly related to the type, scale, and spatial distribution of sedimentary systems in sag areas, and reveals that the Lishu Fault Depression underwent an evolution from a volcanic-rock uplift-fault joint control depression model to a dustpan-shaped fault depression source-sink system, providing a robust basis for more accurate prediction of sedimentary reservoir distribution.

As an important component of unconventional oil and gas resources, the development of shale reservoirs relies on effective reservoir stimulation technologies such as volumetric fracturing, and the effectiveness of volumetric fracturing is significantly influenced by the selection of well locations and fracturing stages. To enhance the accuracy of identifying optimal well locations and fracturing stages, a three-dimensional (3D) integrated modeling method for geological and mechanical properties based on multi-data synergy is adopted. Taking the shale oil reservoir of the Yanchang Formation in the Longdong area as the research object, a 3D geological structure model of the reservoir is established based on layered logging interpretation data, and a 3D mechanical property model is obtained by inverting the regional 3D rock mechanical distribution using logging-derived rock strength parameters, in-situ stress, and brittleness index. On the basis of evaluating reservoir fracturability using brittleness index and stress difference, fracture toughness parameters are introduced, and the spatial distribution of fracturability characteristics in the 3D reservoir space is derived by integrating a fracturability evaluation model, ultimately achieving the 3D scale evaluation of reservoir fracturability. The results indicate that in the study area, Poisson􀆳s ratio ranges from 0. 1 to 0. 3, Young􀆳s modulus from 10 to 50 GPa, maximum principal stress from 25 to 55 MPa, minimum principal stress from 25 to 50 MPa, brittleness index from 15% to 55% , and fracturability index from 0. 1 to 1. 0, with the accuracy of simulation results for Poisson􀆳s ratio, Young􀆳s modulus, maximum principal stress, and minimum principal stress all exceeding 80% . Combined with well testing data, the correlation coefficient between the fracturability index and daily oil production reaches 0. 891. According to the research results, the fracturability of the study area is mainly controlled by the horizontal stress difference, and the overall rock mechanical parameters and fracturability evaluation index exhibit a distribution pattern of “high in the southeast and low in the northwest”, which is inversely related to the stratigraphic depth, among which areas with significant variations in stratigraphic depth show better fracturability.

The increasing demand for target detection accuracy in applications such as land resource surveys, urban planning, ecological monitoring, and disaster early warning, when using high-resolution remote sensing images from drones and satellites, has exposed limitations in traditional detection methods. These limitations are particularly noticeable when there are significant scale differences, complex backgrounds, low contrast, and sparse samples. In particular, detecting small targets in multi-scale and complex background scenes has been challenging. To address these issues, the authors propose an improved YOLO (you only look once) small target remote sensing image recognition algorithm called PSC --YOLO ( parallel spatia channel YOLO). It is based on the YOLO11n framework and incorporates multiple feature enhancement and optimization mechanisms. These additions improve the model􀆳s ability to handle small targets and complex backgrounds. First, the PMKCA ( parallel multi-kernel channel attention) module is introduced into the backbone network. It uses parallel multi-core convolution and channel attention mechanisms to enhance multi-scale feature extraction and improve global feature modeling. Second, the SPPCA (spatial pyramid pooling channel attention) module is embedded into the SPPF (spatial pyramid pooling fast) feature fusion layer. It employs multi-scale pooling and channel attention mechanisms to boost small target perception. Next, the C3k2 HLCA ( hybrid local channel attention) module is integrated into the C3k2 structure. It enhances local feature representation and optimizes feature expression using channel attention mechanisms, which further improves small target detection accuracy. Finally, an adaptive confidence threshold adjustment function is designed to optimize the NMS (non-maximum suppression) process. This reduces redundant detection boxes and improves performance. Experimental results show that PSC --YOLO outperforms YOLOv5, YOLOv10, YOLO11n, and YOLO12 on the NWPU VHR--10 (Northwestern Polytechnical University very high resolution--10) dataset. For the mAP50 and mAP50--95 metrics, PSC--YOLO achieves a 0. 8% and 2. 0% improvement over YOLOv5, a 1. 5% and 2. 0% improvement over YOLOv10, a 0. 8% and 2. 0% improvement over YOLO11n, and a 1. 5% and 2. 0% improvement over YOLO12. The results demonstrate that PSC-- YOLO effectively reduces missed detections in complex background and multi-scale target scenarios. It also improves small target detection accuracy and provides better stability.

Foundation bearing capacity is a key parameter for evaluating the stability and load-bearing performance of foundations. In this study, the difficulty of simultaneously achieving accuracy, economy, and efficiency in the determination of foundation bearing capacity using the standard penetration test ( SPT) and the plate load test (PLT) is addressed. Therefore, a method for the rapid and accurate determination of foundation bearing capacity parameters is proposed, aiming to improve the efficiency and accuracy of geotechnical investigations. Taking the sandy foundation in the Xilinhot area as the research object, a method for determining foundation bearing capacity based on a deep learning model is proposed. The method is established using a multi-layer perceptron (MLP) regression model. A dataset consisting of 598 groups of standard penetration test (SPT) blow counts (N) and 13 groups of plate load test (PLT) measured bearing capacities ( f ak) from the study area is collected. The SPT blow count is used as the input variable, while the measured bearing capacity is adopted as the target output. Nonlinear fitting between the input and output variables is performed using the adaptive moment estimation (Adam) optimization algorithm. Traditional statistical regression, polynomial regression, and support vector regression models are selected as comparative models. Model performance verification and comparative analysis are conducted using the mean absolute error (MAE), mean relative error (MRE), and coefficient of determination (R 2 ) as evaluation metrics. The results indicate that the values predicted by the MLP model are in close agreement with those measured by the plate load test (PLT), with an average absolute error of 2. 3 kPa, an average relative error of 0. 9% , and a maximum error not exceeding 5 kPa. Moreover, the prediction accuracy of the MLP model is significantly superior to that of the three traditional regression models. The MLP model can effectively capture the complex nonlinear relationship between SPT and bearing capacity, and its prediction error is much smaller than the safety margin for foundation design, meeting the accuracy requirements of engineering investigation.

The debris flow in Shiren Village, Fuyu City, Jilin Province was selected as the research object, and a debris-flow hazard prediction based on numerical simulation was conducted to quantitatively reveal the motion characteristics, affected area, and hazard distribution of the debris flow under different rainfall return periods. Through field investigation and engineering geological mapping, the topographic and geomorphic characteristics, material source conditions, and developmental status of the debris flow gully were systematically obtained. A highresolution digital elevation model was constructed based on contour data with a 1 m interval, and the study area was divided into regular grids of 5 m × 5 m. The Flo--2D two-dimensional numerical simulation software was applied, the peak discharge of the debris flow was calculated using the rainfall-runoff method, and a single-peak discharge hydrograph was established. The flow depth, velocity, deposition thickness, and affected area of the debris flow under four rainfall return periods, including 10-year, 20-year, 50-year, and 100-year events, were simulated and analyzed, and the rationality of the simulation results was verified by comparison with the calculated total volume of a single debris flow event. On this basis, flow depth and the product of flow depth and flow velocity were selected as hazard classification indicators, and hazard zoning of the debris flow was conducted for the study area. The results indicate that obvious impacts on the downstream area of Shiren Village are produced under all rainfall return periods, and with the increase in rainfall return period, the maximum flow depth, maximum velocity, and affected area of the debris flow show a progressively increasing trend. Under the 100-year return period condition, large deposition thicknesses and flow velocities are formed in the gully and parts of the village, the extent of high-hazard zones is significantly expanded, and severe threats are posed to residential houses, roads, and farmland. The total debris flow volume obtained from numerical simulation is close to the calculated result, with errors remaining within a reasonable range, indicating that the numerical simulation results are highly reliable.

Geological hazard risk assessment is crucial for scientific prevention and control of geological disasters. Lianyungang City, located in northern Jiangsu Province, has extensive metamorphic rock distributions in its low mountain and hilly areas, making it one of the regions with the most developed landslides and collapses in Jiangsu Province. Conducting geological hazard risk assessment in Lianyungang City can provide a scientific basis for geological hazard prevention and control planning and risk management in Lianyungang. Based on the survey data from Lianyungang's geological hazard risk census, this study conducted susceptibility assessment using five indicators: historical disaster point density, terrain slope, engineering geological rock groups, etc. The information quantity   model was applied for analysis through the ArcGIS multi-source data processing platform. Hazard assessment was performed based on the temporal probability of a 50-year return period rainfall. The comprehensive vulnerability results were obtained by superimposing the vulnerability of buildings, population, and transportation facilities in the study area. Ultimately, the geological hazard risk zoning in the study area was evaluated. The results indicate that Lianyungang City is classified into three risk levels: low, medium, and high, accounting for 9. 71% , 1. 59% , and 0. 02% of the whole city area. The low-risk areas in the city are mainly distributed in the hilly areas of the northwest of Ganyu District and the northwest of Donghai County. The medium risk areas are mainly distributed at the foothills of Houyuntai Mountain in Lianyun District, Qianyuntai Mountain and Jinping Mountain in Haizhou District, Dayi Mountain in Guanyun County, Anfengshan, Fangshan, and Hushan in Donghai County, and Xushan--Dajinshan-- Liujiashan in Ganyu District. The high-risk areas are mainly distributed in the Maoheling--Yandunshan--Erzhijian area of Houyuntai Mountain in Lianyun District, and around the Qishi􀆳erdong of Qianyuntai Mountain in Haizhou District. The delineated risk zones align with the actual distribution of geological disasters, validating the applicability of the information quantity model in geological hazard risk assessment within the study area. This research provides scientific support for the dual control management of “hidden danger points + risk zones” for geological hazards in Lianyungang City, demonstrating practical value.