Volcanic oil and gas reservoirs are generally buried deep, which leads to a high whole-well coring cost, and the degree of development and size of reservoirs are controlled by volcanic facies. Therefore, accurately identifying volcanic facies by logging curves not only provides the basis of volcanic reservoir prediction but also saves costs during exploration. The Songliao Basin is a ‘fault-depression superimposed’ composite basin with a typical binary filling structure. Abundant types of volcanic lithologies and facies are present in the Lishu fault depression. Volcanic activity is frequent during the sedimentary period of the Huoshiling Formation. Through systematic petrographic identiffcation of the key exploratory well (SN165C) of the Lishu fault-depression, which is a whole-well core, it is found that the Huoshiling Formation in SN165C contains four facies and six subfacies, including the volcanic conduit facies (crypto explosive breccia subfacies), explosive facies (pyroclastic flow and thermal wave base subfacies), effusive facies (upper and lower subfacies), and volcanogenic sedimentary facies (pyroclastic sedimentary subfacies). Combining core, thin section, and logging data, the authors established identification markers and petrographic chart logging phases, and also interpreted the longitudinal variation in volcanic petro-graphic response characteristics to make the charts more applicable to this area＇s volcanic petrographic interpretation of the Huoshiling Formation. These charts can provide a basis for the further exploration and development of volcanic oil and gas in this area. 

  The naming of rock hand specimens is usually conducted by geological workers based on observed mineral composition, texture characteristics, etc., combined with their own knowledge reserves. The accuracy of identiffcation results is limited by the experience, research interests, and identiffcation level of the identiffer, as well as the complexity of the rock composition. To improve the efffciency of rock hand specimen identification, this paper proposes a method for rock image recognition and classification based on deep learning and the Inception-v3 model. It encompasses the preprocessing of collected photographs of typical intrusive rock hand specimens, along with augmenting the sample size through data augmentation methods, culminating in a comprehensive dataset comprising 12501 samples. Experimental results show that the model has good learning ability when there is sufffcient data. Through iterative training of the Inception-v3 model on the rock dataset, the accuracy of rock image recognition reaches 92.83%, with a loss of only 0.2156. Currently, several common types of intrusive rocks can be identified: gabbro, granite, diorite, peridotite, granodiorite, diabase, and granite porphyry. Software is developed for open use by geological workers to improve work efffciency. 

 The Erguna ductile shear zone is situated in the Erguna Massif, which has been exposed along the eastern bank of the Erguna River in northeastern China. The authors present comprehensive study results on the macro- and micro-structures, ffnite strain and kinematic vorticity, quartz electron backscatter diffraction (EBSD) fabrics, and geochronology of granitic rocks in the Erguna ductile shear zone. The deformed granitic rocks have experienced significant SE-trending dextral strike-slip shearing. Finite strain and kinematic vorticity in all deformed granitic rocks indicate that the deformation is characterized by simple sheardominated general shearing with S-L tectonites. Mineral deformation behaviors and quartz C-axis textures demonstrate that the deformed granitic rocks developed under greenschist to amphibolite facies conditions at deformation temperatures ranging from 450 to 550 ℃. New LA-ICP-MS zircon U-Pb ages indicate that these granitic rocks were formed in Early Triassic (~248.6 Ma) and Early Cretaceous (~136.7 Ma). All the evidence indicates that this deformation may have occurred in Early Cretaceous and was related to the compression resulting from the ffnal closure of the Mongol-Okhotsk Ocean. 

 The Longgang Block is one of the most important parts of the eastern North China Craton, characterized by extensive Late Neoarchean (~2.5 Ga) granulite facies metamorphism. However, it remains uncertain whether it was inffuenced by Paleoproterozoic magmatism-metamorphism. The authors provide a comprehensive analysis of amphibolite in Laojinchang area, southern Jilin Province, through petrographic, geochemical, mineralogical, and zircon dating. The main ffndings are as follows: The mineral assemblage of amphibolite is Hb+Pl+Cpx+Bi+Kf+Q, characteristic of amphibolite facies; zircon U-Pb dating indicates that the metamorphic age of amphibolite is 1 834±33 Ma; the amphibolite has geochemical characteristics of calcium alkaline, with depletion of Nb, Ta, Ti and P. The plagioclase in the amphibolite is oligoclase, belonging to acidic plagioclase. It is speculated that the protolith of the amphibolite is diorite; using geothermobarometer, the peak metamorphic P-T conditions of amphibolite are determined to be 536–593 ℃/ 3.4–5.0 kbar, and the post-peak conditions are 429–566 ℃/1.3–3.1 kbar. The above results indicate that the Paleoproterozoic metamorphism has been superimposed on Longgang Block, linked to a new orogenic event on the northern edge of North China Craton. 

  The reffnement of the 1cm geoid holds signiffcant importance in engineering applications, where the accuracy of the geoid is frequently constrained by its resolution. However, there has been limited exploration into the speciffc relationship between geoid resolution and accuracy. This article aims to address this gap by thoroughly examining said relationship. This study employs the CapRCR modification to calculate the geoid of Gongzhuling City. The ffndings indicate that the accuracy can be enhanced by 2% to 9% through encryption of the geoid resolution from 2.5′×2.5′ to 1.5′×1.5′. Furthermore, this improvement can be augmented by 15% to 21% through encryption of the gravity anomaly to the same resolution. The accuracy of the geoid exhibits a linear relationship with the resolution of gravity anomalies. The theoretical accuracy of the geoid, excluding integration errors, is determined to be 1.21 cm. In engineering applications, opting for a resolution of 30''×30'' can result in the geoid containing only an integration error of 2 mm. However, to attain an accuracy of 1 cm, it becomes imperative to further mitigate data errors. Consequently, the ffnal reffned quasi-geoid accuracy is established at 0.56 mm. 

 The Daerlong granitic complex in Linkou area is located at the convergence position of the Jiamusi and Songliao blocks. A systematic study of field geology, petrography, zircon U-Pb dating and wholerock major and trace elements has been conducted for the Daerlong granitic complex, aiming to determine its formation age, petrogenesis and tectonic setting, and further constrain the nature and evolution of the Mudanjiang Ocean. Field and petrographic observations show that the Daerlong granitic complex mainly consists of three rock types from old to young, i.e., biotite granodiorite, syenogranite and monzogranite. Geochemical data suggest that all the types of granitoids are high in silicon, rich in potassium, moderate in aluminum (A/CNK=0.94–1.10), poor in iron and magnesium, rich in LILEs and depleted in HFSEs, belonging to the weakly peraluminous high-K calc-alkaline series. Combined with mineral assemblages and geochemical discrimination diagrams, it can be determined that the studied granitoids are of igneous crustderived I-type origin, which underwent strong fractional crystallization and crystal accumulation during magmatic evolution. Zircon LA-ICP-MS U-Pb dating results show that the different types of granitoids were emplaced in a wide age range from 301 to 240 Ma, indicating a long-lived Late Carboniferous to Middle Triassic granitic magmatism occurred in the western Jiamusi Block. The Daerlong granitoids have similar geochemical characteristics of subduction-related igneous rocks. Considering the spatial and temporal distribution of Late Paleozoic to Early Mesozoic igneous rocks within eastern Heilongjiang Province, it is concluded that the Daerlong granitic complex was formed in an active continental margin setting rather than a continental rift environment. The results suggest that the Mudanjiang Ocean might not be a limited ocean evolved from the rifting of the uniffed Jiamusi-Songnen microcontinent. 

 The superparamagnetic effect arises from the superparamagnetism exhibited by a multitude of nano-sized magnetic mineral particles under an external electric ffeld. This phenomenon manifests in transient electromagnetic data primarily as a deceleration in the attenuation rate of late-stage signals, a characteristic difffcult to discern directly from airborne transient electromagnetic signals, consequently leading to signiffcant misinterpretations of subterranean electrical structures. This study embarks on 3D forward modeling of airborne electromagnetic responses in the frequency domain, accounting for the superparamagnetic effect, utilizing an unstructured finite element method. Superparamagnetic responses in the time domain were obtained through frequency-time conversion. This investigation explores the influence of various parameters—such as magnetic susceptibility, time constants, and ffight altitude—on the superparamagnetic effect by examining the response characteristics of typical targets. Findings indicate that in its late stages, the superparamagnetic effect can induce a relative anomaly of up to 300%. There is a positive correlation between magnetic susceptibility and the strength of the superparamagnetic effect. The inffuence of the time constant's upper and lower limits on the superparamagnetic effect is minimal; however, the range between these limits significantly affects the effect, showing a negative correlation with its intensity. Higher flight altitudes weaken the superparamagnetic signal. The impact is most pronounced when superparamagnetic minerals are shallowly buried, effectively shielding the underlying geology with the characteristics of a good conductivity anomaly, but this effect diminishes with greater depth. The insights from this study provide a theoretical framework for a deeper understanding of the superparamagnetic effect in transient electromagnetic signals and for more accurate interpretations of subterranean geological and electrical structures. 

 The basin marginal fault system is the key to understand the formation and evolution of Songliao Basin. In order to investigate the inffuence of marginal fault system on the structural evolution of Songliao Basin, a comprehensive study was conducted on Shiling Town and Zhuanshanhu area of Yehe Town in Siping City of Jilin Province, where is the southeastern margin of the Songliao Basin and there are a series of well-exposed fault, fold and intrusive bodies belonging to the main marginal fault system of the Songliao Basin known as the Jiamusi-Yitong (Jia-Yi) fault zone. Through proffle measurement and ffeld investigation, samples with various lithologies and distinctive features were collected. Detailed ffeld and laboratory works include component and microstructure analysis of these samples, rock-rock contact analysis, main strike measurement and statistics analysis. These data reveal the structural characteristics of the fold, fault and intrusive bodies in the study area. The research results show that the folds are distributed in the Mesozoic strata near the main fault of the eastern branch of the Jia-Yi fault zone, and the folded strata involve the Cretaceous Denglouku and Quantou formations. In addition, the section is dominated by high-angle strikeslip thrust faults. Light-colored veins and dark-colored veins are extensively distributed in the exposed granites. Statistical analysis of joint and fault attitudes in the study area reveals a right-lateral strike-sliping along the main fault. The large-scale right-lateral strike-slip and thrust fault system in Shiling Town occurred in right-lateral transpressive stage in Late Cretaceous. Based on the results above, tectonic evolution sequence in Shiling section of the Jia-Yi fault zone during the Mesozoic can be divided into ffve stages: Middle Jurassic left-lateral ductile strike-slip stage, Late Jurassic compression stage, Early Cretaceous tension stage, Early Cretaceous extension stage and Late Cretaceous right-lateral transpressive stage. These may have important constraint on understanding the Mesozoic evolution of the Songliao Basin. 

 A single-layer monument Svobodny, ancient man＇s parking lot-1, discovered in 2021 as part of archaeological work to study the zone of economic development of the Amur region was investigated lithologically and palynologically. Based on the results of geomorphological analysis of the territory, the study of artifacts, palynological data, as well as analogy with previously identiffed and sufffciently studied relics in the region, the existence of the Osinoozersk late Neolithic culture in this territory is assumed. The time of its expansion in the Amur region is determined within the framework of the second half of the IV millennium BC to the ffrst half of the II millennium BC. The preliminary results of palynological analysis suggest the existence of a temperate climate here, was close to the modern one, which does not contradict the reconstructed paleoclimate and environments of the region during the Holocene period. 

 The exploration of urban underground spaces is of great signiffcance to urban planning, geological disaster prevention, resource exploration and environmental monitoring. However, due to the existing of severe interferences, conventional seismic methods cannot adapt to the complex urban environment well. Since adopting the single-node data acquisition method and taking the seismic ambient noise as the signal, the microtremor horizontal-to-vertical spectral ratio (HVSR) method can effectively avoid the strong interference problems caused by the complex urban environment, which could obtain information such as S-wave velocity and thickness of underground formations by fitting the microtremor HVSR curve. Nevertheless, HVSR curve inversion is a multi-parameter curve fftting process. And conventional inversion methods can easily converge to the local minimum, which will directly affect the reliability of the inversion results. Thus, the authors propose a HVSR inversion method based on the multimodal forest optimization algorithm, which uses the efffcient clustering technique and locates the global optimum quickly. Tests on synthetic data show that the inversion results of the proposed method are consistent with the forward model. Both the adaption and stability to the abnormal layer velocity model are demonstrated. The results of the real ffeld data are also veriffed by the drilling information. 

Flood disasters can have a serious impact on people's production and lives, and can cause huge losses in lives and property security. Based on multi-source remote sensing data, this study established decision tree classification rules through multi-source and multi-temporal feature fusion, classified ground objects before the disaster and extracted flood information in the disaster area based on optical images during the disaster, so as to achieve rapid acquisition of the disaster situation of each disaster bearing object. In the case of Qianliang Lake, which suffered from flooding in 2020, the results show that decision tree classification algorithms based on multi-temporal features can effectively integrate multi-temporal and multi spectral information to overcome the shortcomings of single-temporal image classification and achieve ground-truth object classification.

  Plenty of high-resolution paleoclimate investigations of the last thousand years were carried out to potentially predict future climate changes. Mountainous ombrotrophic peatland is one of the best recorders for high-resolution paleoclimate studies in the forest area. Grain size analysis was carried out on ombrotrophic peat proffle in the eastern mountainous region of Jilin Province, Northeast China. The peat proffle lasts the past 2 000 a by four radiocarbon (AMS14 C) ages. The results showed that the inorganic minerals in the peat proffle are mainly silt, with some contribution from clay and a minor amount of sand, which are mainly due to wind dust and suspended transportation. Two paleoclimate stages are found in this peat proffle by phytolith analysis, peat cellulose isotope research and historical documents: ca. 45–1550 AD, relatively cold period; ca. 1550 AD–present, relatively warm period. This ffnding is important for the initial study of paleoclimatic changes over the last 2 000 a in the mountainous area of eastern mountainous area, Jilin Province, Northeast China.

Since the Paleozoic, the tectonic evolution of northeastern Eurasia has been primarily influenced by the Paleo-Asian Ocean and the Paleo-Pacific tectonic domains. However, the spatial and temporal frameworks, as well as the timing of the tectonic transition between these two oceanic domains, remain unclear. For addressing these issues, we present petrological, geochronological, and geochemical data for andesite and sandstone samples from the Seluohe Group along the Jilin-Yanji Suture between the Jiamusi Khanka Block and the North China Craton. The geochemical results indicate that the andesite sample is high-Mg andesite. Its magma source was generated by the metasomatized mantle wedge influenced by f luids derived from the subducted slab in a continental island arc setting. The high-Mg andesite gives the crystallization ages of Early Triassic (249±3 Ma). The sandstone is immature greywacke with a maximum depositional age of Early Triassic (247±1 Ma), and its sediments primarily originate from concurrent magmatic rocks within a juvenile continental arc. Based on our new findings, we propose that the Seluohe Group represents an Early Triassic volcanic-sedimentary association with continental island arc characteristics associated with the southwestward subduction of the Heilongjiang Ocean. We identified a sedimentary basin intimately associated with one or more continental arcs along the northeastern edge of the North China Craton. We suggest that the southwestward subduction of the Jilin-Heilongjiang Ocean in the Early Mesozoic accounts for this continental arc setting. There is a distinct temporal gap between the closure of the Paleo-Asian Ocean (ca. 260 Ma) and the onset of Paleo-Pacific plate subduction (234–220 Ma), which is essentially coeval with the southwestward subduction of the Jilin-Heilongjiang Ocean between 255 Ma and 239 Ma.

 Current data-driven deep learning (DL) methods typically reconstruct subsurface velocity models directly from pre-stack seismic records. However, these purely data-driven methods are often less robust and produce results that are less physically interpretative. Here, the authors propose a new method that uses migration images as input, combined with convolutional neural networks to construct high-resolution velocity models. Compared to directly using pre-stack seismic records as input, the nonlinearity between migration images and velocity models is signiffcantly reduced. Additionally, the advantage of using migration images lies in its ability to more comprehensively capture the reffective properties of the subsurface medium, including amplitude and phase information, thereby to provide richer physical information in guiding the reconstruction of the velocity model. This approach not only improves the accuracy and resolution of the reconstructed velocity models, but also enhances the physical interpretability and robustness. Numerical experiments on synthetic data show that the proposed method has superior reconstruction performance and strong generalization capability when dealing with complex geological structures, and shows great potential in providing efffcient solutions for the task of reconstructing high-wavenumber components. 

  Unmanned aerial vehicle transient electromagnetic (UAV-TEM) is a novel airborne exploration method that offers advantages such as low cost, simple operation, high exploration efffciency and suitability for near-surface exploration in complex terrain areas. To improve the accuracy of data interpretation in this method, the authors conducted a systematic three-dimensional (3D) forward modeling and inversion of the UAV-TEM. This study utilized the finite element method based on unstructured tetrahedral elements and employed the second-order backward Euler method for time discretization. This allowed for accurate 3D modeling and accounted for the effects of complex terrain. Based on these, the influence characteristics of ffight altitudes and the sizes, burial depths, and resistivities of anomalies are compared and analyzed to explore the UAV-TEM systems’ exploration capability. Lastly, four typical geoelectrical models of landslides are designed, and the inversion method based on the Gauss-Newton optimization method is used to image the landslide models and analyze the imaging effect of the UAV-TEM method on landslide geohazards. Numerical results showed that UAV-TEM could have better exploration resolution and ffne imaging of nearsurface structures, providing important technical support for monitoring, early warning, and preventing landslides and other geological hazards. 

A genus within the family Douvillinidae of the order Strophomenida from the Erdaogou Member of the Xibiehe Formation in the Early Devonian of central Jilin has been re-examined, with consideration

The quest for enrichment model of continental shale oil in the Zhanhua Sag of the Jiyang Depression in the Bohai Bay Basin to provide reference for exploration and development requires a comprehensive approach. Therefore, this study employs rock pyrolysis, Scanning Electron Microscopy (SEM), X-Ray diffraction analysis (XRD), Nuclear Magnetic Resonance (NMR), and other experiments to analyze the conditions for shale oil enrichment and establish its patterns. The results show that favorable hydrocarbon generation potential and appropriate thermal maturation degree control “in situ enrichment”; while the storage capacity and the mobility of shale oil determine “migration enrichment.” In the process, the TOC governs the oil-generating capacity of shale with medium to large pores and microfractures serving as the main enrichment spaces and migration pathways for shale oil. Based on the deposition model, the study area can be divided into five lithofacies stages (I-algal limestone, II-laminated marl, III-laminated recrystallized limestone, IV-laminated mudstones, and IV-blocky calcareous mudstones). Integrating the geochemical parameters into the sedimentary patterns makes it clear that the study area underwent two phases of hydrocarbon expulsion during the thermal evolution of source rocks (Stage II: 3 060–3 120 m and Stage IV: 3 020–3 040 m). However, judging by the observed TOC (2% to 5.6%), thermal maturity (Ro>0.8%), S1 (>2 mg/g) and OSI (>100 mg/g) as well as moderate basin size, climate, and quantity of terrestrial input, the blocky calcareous mudstones (Stage IV) have better oil-prone characteristics and potential to generate a substantial quantity of hydrocarbons at this stage. More so, with a brittleness index exceeding 60%, it exhibits favorable fracturability accounting for the main controlling factors and enrichment patterns of shale oil in the area. Hence, this study further enriches and develops the theoretical understanding of shale oil enrichment in the area, provides valuable insights for future exploration of continental shale oil in eastern China and other similar basin around the world.

To determine the geological age, petrogenesis, and tectonic setting of Mesozoic volcanic rocks in the Ningyuancun Formation in Xunke area, Lesser Hinggan Range, the zircon U-Pb geochronology, petrographic observations, and geochemical analyses of major and trace elements were conducted in this study. Zircon U-Pb dating showed that the volcanic rocks of the Ningyuancun Formation were formed in the Early Cretaceous (112.97±0.90 Ma). Major element analyses revealed that the content of SiO? weighted from 74.14% to 76.54%, indicating the volcanic rocks to be high-silica and felsic. The content of AlO varies from 12.48% to 13.65%. A total alkali content of the volcanic rocks range between 8.46% and 9.56%, with Na?O/K?O ratios from 0.69 to 0.89. This indicated that the volcanic rocks belonged to a highly differentiated calc-alkaline series. Additionally, A/CNK values range from 0.950 to 1.015, and A/NK values vary between 0.999 and 1.127, suggesting a peraluminous characteristic. Trace element analysis showed a right-sloping “V-shaped” REE pattern, with the enrichment in light REEs and a prominent negative anomaly of Eu. The volcanic rocks are enriched in Rb, Th, U, La, and Ce, while Ba, Sr, and Ti are depleted. Rb/Sr ratio ranges from 10.01 to 12.46, Ti/Y ratio is from 51.14 to 95.72, and Ti/Zr ratio is from 5.78 to 6.41. It is suggested that the magma was derived from the partial melting of crustal rocks. This evidenced that the Early Cretaceous high-silica rhyolites were formed in an intra continental extension in eastern Northeast China during the northwestward subduction of the Pacific Plate. The crustal extension, asthenospheric mantle upwelling and underplating of mantle-derived magmas resulted in the residual crystalline mush in Early Cretaceous mafic magma chambers to erupt.

During Early Cretaceous, NNE-trending extensional basins filling with various volcanic sedimentary formations developed in the northeastern Da Hinggan Ling (Mts.), northeastern China. This study investigates the formation age and geological background of Jiufengshan Formation, providing insights into its tectonic setting and formation mechanisms. Detrital zircons from four sandstone samples of Jiufengshan Formation in Nenjiang area indicate a maximum depositional age of 116±1 Ma, corresponding to late Early Cretaceous. Petrographic analysis and zircon age peak comparisons suggest these sandstones originated from proximal deposits with nearby provenances of earlier and contemporaneous volcanic rocks. Further research on the sandstone framework and trace elements in detrital zircons indicates that the formation process of Jiufengshan Formation was likely related to the low-angle subduction of the Paleo Pacific plate.

There have always been academic debates regarding the timing and geodynamics of the superimposition and transformation between the Paleo-Pacific Ocean and the Paleo-Asian Ocean. To resolve the relevant issues over this debate, the authors selected the Jilin–Heilongjiang high-pressure metamorphic belt (Ji–Hei HP Belt) between the Jiamusi–Khanka Block and the Songliao Block in NE China as the study area. This area preserves important records of the superimposition and transformation between these two tectonic domains. This study aims to address this issue through geochemical and zircon U–Pb dating analyses of the Yilan blueschist of Heilongjiang Complex exposed in the Ji–Hei HP Belt. In the geochemical analysis, it has been discovered that the protoliths of the blueschist in the Yilan area consist of subalkaline basalt, which displays geochemical characteristics of Ocean Island Basalt that indicated an oceanic island setting. The LA–ICP–MS zircon U–Pb analysis yields ages of 248±4 Ma and 259±2 Ma from the magma zircons of the blueschists, indicating that the basalt protolith was formed in Late Permian to Early Triassic (259–248 Ma). Based on the results of this study and the regional data, it is proposed that the Jilin–Heilongjiang Ocean opened during Late Permian to Early Triassic (259–248 Ma). This period marks a crucial stage from the closure of the Paleo-Asian Ocean to the initiation of Paleo-Pacific oceanic subduction.

The Tangjiashan lead-zinc deposit, located on the southwestern margin of the Sichuan Basin, is rich in bitumen, and the lead-zinc ore and bitumen coexist closely, indicating a close genetic relationship between lead-zinc mineralization and hydrocarbon reservoir formation. However, whether bitumen shares the same source as the current gas reservoirs within the basin or other destroyed gas reservoirs along the basin margins remains unknown. Here, we conducted an organic geochemical analysis of bitumen in this deposit and identified the sources of hydrocarbons by comparing biomarker compounds with those of potential source rocks. The authors found that the bitumen in the Tangjiashan lead-zinc deposit has good comparability with the hydrocarbon source rocks of the Cambrian Qiongzhusi Formation, suggesting that the primary sources of oil in this ancient hydrocarbon reservoir are muddy source rocks of the Qiongzhusi Formation. This research is important for enhancing the understanding of the genetic connection between lead-zinc mineralization and hydrocarbon formation, providing crucial insights for strategies to explore both metal ores and hydrocarbons and advancing the geological understanding of petroleum systems in the Sichuan Basin.?

This study presents LA–ICP–MS U–Pb dating and whole-rock geochemical analyses of the Late Triassic Gangshan harzburgite in the Qingyuan area, with the aim of elucidating its petrogenesis and further constraining the early Mesozoic tectonic evolution of the eastern segment of the northern margin of the North China Block (NCB). Zircons from the harzburgites exhibit typical oscillatory growth zoning or striped absorp tion in cathodoluminescence images. U–Pb analyses of zircons yield ages ranging from 2 525 Ma to 225 Ma, with two youngest ages (225±7 Ma) indicating that the harzburgites were formed during Late Triassic. Geochemical analyses of the Gangshan harzburgites show that the rocks have low concentrations of SiO2 (42.38%–42.85%) and Al2 O3 (3.31%–3.33%), along with high concentrations of MgO (41.32%–41.76%), Cr (4 856×10-6–5 191×10-6) and Ni (1 942×10-6–2 041×10-6). They also display low REE abundances (∑REE=4.38×10-6–4.69×10-6) and flat REE patterns with low (La/Yb)N ratios (1.24–1.56) and slightly po- sitive Eu anomalies (δEu=1.13–1.16). These features suggest that the Gangshan harzburgites are cumulates of basaltic magma derived from the depleted lithospheric mantle. Combined with previous studies, these Late Triassic mafic–ultramafic rocks, together with coeval granitoids in adjacent regions, constitute a typical bimodal association, suggesting that they formed in a post-orogenic extensional environment after the final closure of the Paleo-Asian Ocean.

This study selects geochemical data of basalts from different seamounts in the Mid-Pacific Mountains province and conducts analyses of major and trace elements as well as Sr-Nd-Pb isotopes to explore the tectonic evolution, petrogenesis, and mantle-source magama characteristics of the Mid-Pacific Mountains. The basalts from the Mid-Pacific Mountains are predominantly alkali basalts, rich in alkalies, and changing in potassium. They exhibit geochemical features of ocean island basalts (OIB), with distinct fractionation between light and heavy rare-earth elements and a pronounced Ce negative anomaly (δCe = 0.16–1.10, average 0.84), along with enrichment in large ion lithophile elements (LILEs). The Mid-Pacific Mountains are intraplate ocean island basalts formed by mantle plume (hotspot) activity, originating mainly from an enriched mantle magma source region, and most of them have undergone low degree of partial melting and a certain degree of crystalline differentiation, with negligible contamination from oceanic crust materials. The Mid-Pacific Mountains exhibit ratios of 87Sr/86Sr(i) (0.702 733–0.704 313, average 0.703 452) and 143Nd/144Nd(i) (0.512 698–0.512 996, average 0.512846) which are close to the HIMU mantle end member, and ratios of 206Pb/204Pb (18.953–19.803), 207Pb/204Pb (15.54–15.62) and 208Pb/204Pb (38.813–39.514) which are close to the EMII mantle end-member. Combined with the isotopic geochemical characteristics in the West Pacific Seamounts province, the basalts from the Mid-Pacific Mountains were considered to represent a certain proportion of mixing mantle end-members between the HIMU and EMII, possibly formed by the mixing of the HIMU superplume in the South Pacific hotspot region with the EMII secondary mantle plume in the transition zone during their ascent.

 The pore structure of rocks significantly influences the porosity and permeability of reservoirs and the migration ability of oil and gas, and being the key task on the development of volcanic gas reservoirs. Nine volcanic rock samples from the Yingcheng Formation and Huoshiling Formation in the Longfengshan area of the Changling Fault Depression in the Songliao Basin were selected for this study. The pore structures of the volcanic rocks in the study area were investigated using high-pressure mercury injection, X-ray diffraction combined with fractal theory. The relationships between the fractal dimension and physical properties characteristics, pore structure parameters, and mineral content were analyzed to provide guidance for the development of volcanic rock gas reservoirs. The results show that the reservoir can be divided into 3 types (I, II, and III) based on the shape of the capillary pressure curve, and the physical properties deteriorate successively. Different types of reservoirs exhibit different fractal characteristics. For types I, II and III, the average total fractal dimensions were 2.3418, 2.6850, and 2.9203, respectively. The larger the fractal dimension, the stronger the heterogeneity of reservoir. A small number of macro-pores primarily contributed to permeability. The fractal dimension was negatively correlated with porosity and permeability. The fractal dimension of the rock was strongly correlated with quartz and feldspar contents, and the mineral composition and content are closely related to the pore evolution of the reservoir, which are the internal factors affecting the fractal dimension of volcanic rock.

The lower member of Dalazi Formation is an important oil reservoir in the Songjiang Basin. Based on the research on its field-measured geological profiles, lithological combination characteristics and grain size distribution characteristics, combined with the analysis of the spatial distribution characteristics, sedimentary structural characteristics and hydrodynamic conditions of the sediments in this member, nine sedimentary microfacies of the fan delta plain subfacies, fan delta front subfacies and littoral-shallow lacustrine subfacies have been identified.The study reveals that lower member of Dalazi Formation in the research area follows a fan delta–shallow lacustrine depositional model in the steep slope zone of a rift lake basin. The sediments primarily originate from the Pre-Mesozoic strata in the steep southeastern and eastern margins. The basin center migrated from the early Xiaoshahe area to the Yangmucun–Shenglicun area, and the sedimentary system gradually transitioned from fan delta to littoral-shallow lacustrine facies.

To investigate the Early Cretaceous magmatic activity and tectonic evolution in the Xiaoqinggou mining area of Jilin Province, the authors conducted petrological, geochemical, and isotopic analyses of diorite rocks. The findings show that the zircons exhibit distinct magmatic growth zoning, confirming their magmatic origin. LA–ICP–MS zircon U–Pb dating yielded an age of 128.7±2.2 Ma, corresponding to Early Cretaceous. Geochemical data reveal that the diorite rocks are high and potassium but low in sodium, classifying them within the peraluminous, high-potassium calc-alkaline series. They are enriched in large ion lithophile elements (e.g., K, Ba and Rb) and depleted in high field strength elements (e.g., Nb, Ta and Ti). The δEu values range from 1.07 to 1.14, indicating weakly positive Eu anomalies. Regional comparisons and integrated studies suggest that the Xiaoqinggou diorite rocks formed in a volcanic island arc setting, associated with the westward subduction of the Paleo-Pacific plate beneath the Eurasian continent in an extensional tectonic environment. This study provides a theoretical basis for further exploration of the Xiaoqinggou deposit.

 Recurring Slope Lineae (RSL) are seasonally observed dark streaks on the Martian surface that exhibit distinct spatial and temporal distribution characteristics. Exploring their formation mechanisms can deepen our understanding of surface activity on Mars and provide scientific basis for future Mars exploration. This study aims to gain a comprehensive understanding of the spatial and temporal distribution characteristics and formation mechanisms of RSL by reviewing relevant literature and synthesizing various viewpoints and experimental results. RSL typically appear during warm seasons, disappear during cold seasons, and repeat over multiple Martian years. The formation mechanisms can be broadly categorized into three types: dry mode, wet mode, and mixed mode. However, a definitive explanation for the formation of RSL is still lacking, and both the dry and wet models have their respective limitations. It is likely that the formation of RSL is the result of the combined action of multiple mechanisms. The next step should be to search for terrestrial analogs of RSL and conduct research at high spatial and temporal resolutions to understand the forming processes of RSL.

Groundwater overexploitation is the main cause of city surface deformation. In Siping City, groundwater level had decreased since 1980 due to large-scale exploitation of groundwater. Subsequently, the level began to rise under governance while shown a declining trend in the whole Siping area. This paper obtained surface deformation of Siping City from 2017 to 2024 using 36 Sentinel-1B satellite images and 88 Sentinel-1A satellite images based on SBAS-InSAR and analysed the effect of groundwater on deformation. The results indicated that uplift occurs in the centre of the urban area with a maximum average velocity of about 5 mm/y and there were two main subsidence zones during these two time periods with average subsidence velocities of about 3 mm/y and 1.7 mm/y. Groundwater levels showed a high correlation with surface deformation, with rising the levels leading to surface uplift and falling the levels leading to surface subsidence.

There is an issue of groundwater overexploitation in Ningjiang District, Songyuan City, Jilin Province, which has led to land subsidence. To investigate the influence of hydrological elements on surface deformation in Ningjiang District, surface deformation data were obtained by the small baseline subset interferometry synthetic aperture radar (SBAS-InSAR) technique. Initially, Sentinel-1B data were utilized to observe surface deformation in Ningjiang District from 2017 to 2021 with SBAS-InSAR. Subsequently, the geographical detector was employed to quantitatively assess the relationship between land subsidence and its influencing factors. Furthermore, multivariate singular spectrum analysis (M-SSA) was employed to identify periodic fluctuations in surface deformation and groundwater level, revealing the temporal lag between f luctuations in surface deformation and groundwater level. The findings demonstrate that the distance to water bodies accounts for the largest share of subsidence variation, with subsidence shaped by the combined impact of many factors. The results of interaction detection indicate that the interplay between the distance to water bodies and precipitation exhibits the most significant joint explanatory capacity for surface deformation. The observed seasonal cyclical fluctuations in groundwater level and surface deformation indicate a substantial influence of groundwater on surface deformation in the Ningjiang District.

Five new small theropod teeth and one manual ungual have recently been recovered from the Upper Cretaceous Nenjiang Formation in the Songliao Basin. The specimens were examined for their morphological characteristics, leading to the identification of four distinct taxa. The first taxon consists of three foliodont teeth characterized by a pronounced basal constriction and large hook-like distal denticles, which can be attributed to Troodontidae. The second taxon is represented by an elongated tooth featuring prominent longitudinal ridges, allowing for its assignment to Paronychodon. The third taxon is a bladelike tooth with notably small distal denticles, corresponding to Richardoestesia. The fourth taxon comprises a manual ungual characterized by a transversely wide and nearly symmetrical proximal articular surface, fully enclosed ventral foramina, a flattened ventral surface, and the absence of a flexor tubercle, resembling Alvarezsauridae. These specimens significantly enhance the known dinosaur diversity of the Nenjiang Formation and provide crucial insights for understanding the terrestrial ecosystem in Northeast Asia during the Late Cretaceous.

 Evaluation of backfilling effectiveness plays a crucial role in the geological environment management and restoration of abandoned open-pit quarries, providing a scientific basis for subsequent greening efforts. Backfill soil, predominantly composed of silty clay, demonstrates high water retention capacity and elevated moisture content, leading to a pronounced resistivity contrast with the bedrock exposed by quarrying activities. To investigate the distribution of backfill soil subsurface and assess backfilling effectiveness in the study area, this study conducted a comprehensive geophysical investigation utilizing the high-density electrical resistivity tomography (ERT). A total of 19 ERT survey lines were deployed across three distinct areas in Liuyao Village, Huaibei City, Anhui Province, China. The inversion results, derived from both two-dimensional (2D) and three-dimensional (3D), reveal distinct electrical properties of the subsurface materials: the backfill soil layer shows low resistivity features, the fill stone layer exhibits medium to high resistivity, and the bedrock shows the highest resistivity. The 2D inversion results, from the data measured using the Wenner array effectively capture the spatial distribution and structural features of the backfill soil layer. The findings indicate a gradual east-west thinning of the clay layer within the quarry. Furthermore, the northern pit area exhibits a uniform distribution of backfill soil layer, indicative of effective backfilling operations. In contrast, the southern pit area lacks a well-defined clay layer, suggesting suboptimal backfilling effectiveness.

The large-scale acquisition and widespread application of remote sensing image data have led to increasingly severe challenges in information security and privacy protection during transmission and storage. Urban remote sensing image, characterized by complex content and well-defined structures, are particularly vulnerable to malicious attacks and information leakage. To address this issue, the author proposes an encryption method based on the enhanced single-neuron dynamical system (ESNDS). ESNDS generates high quality pseudo-random sequences with complex dynamics and intense sensitivity to initial conditions, which drive a structure of multi-stage cipher comprising permutation, ring-wise diffusion, and mask perturbation. Using representative GF-2 Panchromatic and Multispectral Scanner (PMS) urban scenes, the author conducts systematic evaluations in terms of inter-pixel correlation, information entropy, histogram uniformity, and number of pixel change rate (NPCR)/unified average changing intensity (UACI). The results demonstrate that the proposed scheme effectively resists statistical analysis, differential attacks, and known-plaintext attacks while maintaining competitive computational efficiency for high-resolution urban image. In addition, the cipher is lightweight and hardware-friendly, integrates readily with on-board and ground processing, and thus offers tangible engineering utility for real-time, large-volume remote-sensing data protection.

 The detection of unexploded ordnance (UXO) is critical for battlefield clearance and civilian safety. This study presents the development of a software for automated simulation based on the high frequency structure simulator (HFSS) and the MATLAB application programming interface (API), which together form the HFSS-MATLAB-API. This interface enables control over HFSS and conducts frequency-domain electromagnetic simulations for various types of UXO, including anti-tank mines, grenades, mortars, and aerial bombs. The software automates modelling, solving, data extraction, and analysis through MATLAB, enhancing the efficiency of simulation and enabling flexible settings for target models, coil parameters, and subsurface media. The research utilizes numerical simulation methods to analyze the response characteristics of different types of UXO in electromagnetic induction and explores the impact of the rotation angle of the target model on the attenuation characteristics of the measurement line. The results indicate that the electromagnetic response of UXO varies significantly based on type, burial depth, and spatial orientation. The findings provide a theoretical foundation for the electromagnetic detection, target identification, and classification of UXO.

The Longfengshan structural belt lies in the southern Changling Depression. The Yingcheng Formation is the primary gas-bearing unit. The Yingcheng Formation has low permeability and contains deep, tight gas that is challenging to extract. Industrial gas flow has been achieved from the B218 and B220 well blocks in the sandstone layer of the first member of Yingcheng Formation (Ying I), indicating the potential of this sandstone group for gas production. Although oil and gas are widely distributed in the Ying I sandstone layer, production capacity varies significantly across the formation. into six sublayers. Drilling, logging, and laboratory testing data were integrated to subdivide the Ying I sandstone layer into six sublayers. Core and well logging analyses indicate a braided river delta depositional environment. Data and seismic inversion identify the Ying I-5 sublayer as the primary exploration target. The effective reservoir in the eastern fan body, where porosity ranges from 5% to 13% and maximum effective thickness reaches 34 m. This study basis for optimizing well placement and estimating gas reserve parameters in the Ying I sandstone layer of the Longfengshan area. The findings can guide the development of other tight gas reservoirs.

Previous studies have shown that the Eocene oil shale sequences in the Green River Basin contain long-period astronomical age information. The fine-scale chronological characteristics of the oil shale laminae remain largely unexplored.We selected finely laminated oil shales formed in deep-water environments characterized by stable water column stratification as the primary focus of this study, using microscopy and micro-area X-ray fluorescence (μ-XRF) techniques. By integrating high-resolution elemental data with timeseries analysis, we identified significant periodic signals associated with solar activity (Hale and Schwabe cycles) and ENSO. The results indicate that the alternations of light and dark laminae in the Green River Formation oil shale correspond to alternating dry and wet climate regimes: the light laminae are dominated by carbonate minerals, reflecting drier and milder conditions, while the dark laminae are enriched in terrigenous clastics and organic matter, indicating periods of increased precipitation and warmer temperatures. The detected periodicities (23.5 years, 13.3 years and 5.8 years) are highly consistent with modern observations, demonstrating that the lower Eocene Green River oil shale effectively records short-term solar activity and climate variability. Furthermore, our findings confirm that a persistent "permanent El Niño" state did not develop under Early Eocene greenhouse conditions, providing a refined chronological framework for highresolution paleoclimate studies during greenhouse intervals.

The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution, marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks. These events provide valuable geological records for understanding the tectonic evolution of the Jiao-Liao-Ji Belt. This study focuses on the Paleoproterozoic Chibaisong meta-gabbro in southern Jilin, investigating the source of mafic magma, petrogenesis, and tectonic setting through systematic petrological analysis, zircon U-Pb dating, and geochemical studies. The findings contribute to constraining the dynamic mechanisms of Paleoproterozoic extensional rifting in the Jiao-Liao-Ji orogenic belt. Geochemical data indicate that the samples exhibit low SiO₂(47.99–50.66 wt.%), TiO₂(0.75–3.20 wt.%), Nb(3.22–8.09 ppm), and Ta(0.22–0.51 ppm) contents, along with high TFeO₃(11.97–15.82 wt.%) and MgO(5.67–12.66 wt.%) concentrations. They also show low Nb/La ratios and high (Th/Nb)N values, consistent with the geochemical characteristics of tholeiitic basalts. The samples display low total rare earth element concentrations, weak or absent Eu anomalies, slight enrichment in light rare earth elements, relatively flat heavy rare earth element patterns, and depletion in Nb, Ta, and Ti. The meta-gabbro from southern Jilin exhibits geochemical similarities to Paleoproterozoic metamafic rocks from other regions of the Jiao-Liao-Ji Belt, resembling enriched mid-ocean ridge basalts (E-MORB) with Nb, Ta, and Ti depletion. Integration of previous studies and geochemical data suggests that the 2.16–2.10 Ga metamafic rocks in the Jiao-Liao-Ji Belt experienced contamination by older crustal material. These results indicate that the 2.16–2.10 Ga metamafic rocks are unlikely to be associated with island arc, continental arc, or mid-ocean ridge settings. Instead, they are more likely related to intraplate magmatism associated with continental rifting

Slope units are divided according to the real topography and have clear geological characteristics, making them ideal units for evaluating the susceptibility to geological disasters. Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District, Shenzhen City, Guangdong Province, was selected as the study area. A total of 15 influencing factors,namely Fluctuation,slope, slope aspect, curvature, topographic witness index (TWI),stream power index (SPI),topographic roughness index (TRI), annual average rainfall,distance to water system, engineering rock group,distance to fault, land use,normalized difference vegetation index (NDVI),nighttime light, and distance to road, were selected as evaluation indicators. The information volume model (IV) and random points were used to select non-geological disaster units, and then the random forest model (RF) was used to evaluate the susceptibility to geological disasters. The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models. The results show that the area under the curve (AUC) values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model, which are 0.6% (IV-RF model) and 1.9% (RF model) higher than those for the hydrological slope unit. Based on a comparison of the evaluation methods based on the two types of slope units, the hydrological slope unit evaluation method based on manual correction is highly subjective, is complicated to operate,and has a low evaluation accuracy, whereas the evaluation method based on automatic slope unit division is efficient and accurate, is suitable for large-scale efficient geological disaster evaluation, and can better deal with the problem of geological disaster susceptibility evaluation.

The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region. The primary host rocks of the Mailong gold deposit consist of intermediate-acid intrusive rocks from the Varisian and Indosinian periods, as well as the Precambrian Jinshuikou Group, with mineralization controlled by northeast and northwest faults. The alteration of the host rocks is mainly characterized by silicification, sericitization, chloritization, and carbonatization. Based on the cross-cutting relationships of the veins, the hydrothermal mineralization of the gold deposit can be categorized into three stages: the quartz-pyrite stage, the quartzpolymetallic sulfide stage, and the quartz-carbonate stage. Microthermometry of fluid inclusions indicates that the Mailong gold deposit belongs to a low-density (0.73–0.86 g/cm3 ), medium-temperature (240–340 ℃), and medium-salinity (4.01–10.74 wt% NaCl) NaCl-CO2-H2O fluid system. The C-H-O isotopic analysis suggests that the mineralizing fluids is derived from magmatic water, with later contributions from atmospheric precipitation. In-situ S isotopic results indicate that the mineralizing materials mainly derive from igneous rocks. A comprehensive analysis concludes that the Mailong gold deposit is a mesothermal hydrothermal vein-type gold deposit controlled by structural factors.

The Solonker Suture records the termination of the Central Asian Orogenic Belt (CAOB), but its eastward extension beneath the Songliao Basin has not been clear. The Yaduwula ophiolite is one of the significant fragments within the Solonker Suture. LA–ICP–MS U–Pb dating of zircon grains from metamorphic basalts yield ages of 263±4 Ma and 274±3 Ma, constraining the Yaduwula ophiolite in the late Cisuralian and Guadalupian age. This might indicate that the subduction of Paleo-Asian Ocean continued until at least the Guadalupian (middle Permian). Geochemical analysis of the metamorphic basalts revealed enrichment in large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs) and show the characteristics of a supra-subduction zone. The results provide the evidence for the closure time of the Paleo-Asian Ocean after the middle Permian and also suggest that the Yaduwula ophiolite may be considered the eastern extension of Solonker Suture. Our study provides further insights on the evolution of the southeastern Central Asian Orogenic Belt.