Most Download articles

Published in last 1 year | In last 2 years| In last 3 years| All| Most Downloaded in Recent Month | Most Downloaded in Recent Year|

In last 2 years

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

Middle Neoproterozoic Tectonic Evolution of the Mianlue Tectonic Belt: Evidences from Detrital Zircon U-Pb Geochronology and Geochemistry of the Guantianmen Metasedimentary Rocks in Lueyang County WANG Zhaoyang, PEI Xianzhi, LI Ruibao, PEI Lei, LI Zuochen, LIU Chengjun, ZHAO Shaowei, WANG Meng, CHEN Youxin, ZHOU Hai, ZHAO Jie, XU Lili Geoscience    2022, 36 (03): 770-795.   DOI: 10.19657/j.geoscience.1000-8527.2022.015 Abstract （218）   HTML （15）    PDF（pc） （11669KB）（389）       Knowledge map    Save A suite of greenschist to lower-amphibolite-facies metasedimentary rocks is exposed at Guantianmen in the Mianlue tectonic belt, and is characterized by intense ductile deformation. The depositional ages and tectonic settings of these rocks have long been controversial, which limits our understanding on the regional tectonic evolution. To constrain their depositional ages and tectonic settings, we conducted petrology, petrogeochemistry, and LA-ICP-MS detrital zircon U-Pb dating on the metasedimentary rocks. The results show that protoliths of the Guantianmen metasedimentary rocks are a set of fine-grained clastic rocks with local carbonate interbeds. Our work indicates that the metasedimentary rocks have undergone low-degree chemical weathering and sedimentary recycling, and were mainly derived from felsic to intermediate igneous rocks with continental arc signature. Two samples yielded similar age distributions, displaying a dominant ca.880-800 Ma age group with a main age peak at ca.830 Ma. The youngest age group is 747-736 Ma(avg.742±6 Ma). Combined with previous work, we suggest that the main provenance region of the Guantianmen metasedimentary rocks is the Early-Middle Neopro-terozoic magmatic arc in the Bikou and Hannan-Micangshan microblocks. The depositional age of the Guantianmen metasedimentary rocks should be later than 720 Ma. The rocks were most likely deposited in an extensional rift system during the middle-Late Neoproterozoic, in response to the Rodinia supercontinent breakup. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochemical Characteristics and Genesis of Pinghe Crystalline Graphite Deposit in Sichuan Province XIA Jinsheng, SUN Li, ZHANG Peng, CHEN Changkuo, WANG Junzhu, SI Jiangfu Geoscience    2022, 36 (06): 1486-1496.   DOI: 10.19657/j.geoscience.1000-8527.2022.06.04 Abstract （222）   HTML （6）    PDF（pc） （6553KB）（387）       Knowledge map    Save The Pinghe scaly graphite deposit,one of the crucial graphite deposits in China,located on the Micangshan-Dabashan thrust belt of upper Yangtze Block.Field survey,mineralogical and geochemical analysis of graphite bearing metamorphic rocks were carried out to study the ore genesis of this deposit.The ore bodies are hosted in the Mawozi Formation of the Mesoproterozoic Huodiya Group.The ore bodies which conform to the wall rocks mainly display bedding to lenticular occurrence.The host rocks of the deposit are mainly graphite schists and minor graphite bearing dolomotic marbles.The average fixed carbon content of the ore bodies is 16.32%.Graphites in the ore bodies mainly show flake textures with big flakes (>0.15 mm) of 37% and small to middle flakes (<0.15 mm) of 63%.The analysis on major and trace elements indicates that the protolith of the graphite-bearing schist has affinity to terrigenious argillaceous siltstone.Zircon SHRIMP U-Pb dating yields the metamorphic age of the graphite-bearing schist at (751.6±4.5) Ma.The δ13C of graphites averages on -24.17‰,which indicates the genesis of graphite in the deposit is mainly attributed to organic carbon.Therefore,we infer that the formation of the Pinghe deposit is closely linked to an organic origin and regional metamorphism. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Site Selection Strategy for An Annual Million-Ton Scale CO2 Geological Storage in China WANG Zijian, TANG Xuan, JING Tieya, YOU Mingxin, ZHANG Jinchuan, LI Zhen, ZHOU Juan Geoscience    2022, 36 (05): 1414-1431.   DOI: 10.19657/j.geoscience.1000-8527.2022.044 Abstract （356）   HTML （18）    PDF（pc） （4500KB）（331）       Knowledge map    Save CO2 geological storage are very important technology for the sustainable development for the industries with difficulties in reducing CO2 emissions. Compared with some countries that have succeeded in large CO2 geological storage projects with storage capacity of over a million tons per year, China’s CO2 geological storage projects are still in early stage, most projects in the size of 100,000 tons per year. China still lacks experience in CO2 storage site selection, injection and monitoring of large(>1 m tons CO2/year) CO2 geological storage projects. We classify the storage space into two types in term of their geological type, e.g. structural traps (anticline, fault and fracture) and lithologic traps (sandstone and carbonate reef). Based on the study of 15 large CO2 geological storage projects around the world, four classes of indices for site determination were summarized, storage size, injecting capacity, safety and economic evaluation. The site selection principle and parameters for CO2 geological storage sites with an annual storage capacity of one million tons are defined. In terms of basin types and geological characteristics of China, different CO2 storage strategies need to be adopted. For instance, for large cratonic basins, such as the Ordos and Songliao basins, which contain wide distribution of sandbodies, and large-scale anticline and lithologic traps, they provid the potential for large-scale deep saline aquifers or depleted petroleum reservoir storage site. For the fault-bound basins such as the Bohai Bay and China offshore basins, well-developed faults or fault-related traps provide only small storage capacity and they are easily influenced by sealing effectiveness. It is thus necessary to adopt the strategy of comprehensive evaluation of trap groups with dynamic evaluation of fault activity; as for the superimposed basin in western China, the structural thrust belts on the basin margin have generally intensive tectonic stress, and great difficulty in CO2 injection. This brings high risk for CO2 injection and storage. Instead, the paleouplifts and slopes in the basin center may represent effective storage sites. Therefore, the evaluation strategy for basins in western China would need to consider zoning and stratification. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Development of the Chinese Continental Scientific Deep Drilling: Perspectives and Suggestions ZOU Changchun, WANG Chengshan, PENG Cheng, WU Caowei, GAO Yuan Geoscience    2023, 37 (01): 1-14.   DOI: 10.19657/j.geoscience.1000-8527.2022.101 Abstract （411）   HTML （43）    PDF（pc） （2533KB）（313）       Knowledge map    Save As the most direct and important method to detect the Earth’s deep interior, scientific drilling plays a key role in solving the strategic technological issue of deep Earth exploration. This study briefly reviews the development and current situation of domestic and international continental scientific drilling and deep drilling, and analyzes the characteristics and trends of continental scientific drilling development. We summarized the Chinese Continental Scientific Drilling, its key scientific and technological issues, as well as challenges and opportunities. Accordingly, we proposed the development goals, priorities and approaches of the Chinese Continental Scientific Drilling. Continental scientific deep drilling can provide a unique pathway for investigating global concerns in Earth sciences, such as geodynamic processes, geohazards, mineral and energy resources, and environmental changes. However, its implementation depth is constrained by ultra-high temperature and ultra-high pressure in harsh borehole environments. Modern scientific advances have promoted the development of various technologies in continental scientific drilling, which provide important support for ultra-deep and extra-deep drilling. The Chinese Continental Scientific Drilling should aim for 9,000-15,000 m extra-deep boreholes, focusing on scientific issues in the fields of ultra-deep, deep-time and deep-observation. Priority development directions can include deep Earth tectonics, deep-life, deep-climate, and deep-resources. The priority detection technologies can include those for drilling, logging, and long-term observation in ultra-high temperature-pressure environments. Priority should also be given to the experimental technique development for ultra-deep matter, dynamics processes, and petrophysics. This would promote a breakthrough in the capacity and level of Earth interior detection in China. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochronology and Petrogenesis of the Highly-Fractionated Early Cretaceous Narenwula Granite, Inner Mongolia, China LI Zhu, ZHANG Dehui, ZHANG Rongzhen, SHEN Cunli, JIAO Shihao, LI Lin, ZHU Penglong Geoscience    2022, 36 (03): 848-861.   DOI: 10.19657/j.geoscience.1000-8527.2021.064 Abstract （368）   HTML （8）    PDF（pc） （10778KB）（300）       Knowledge map    Save A number of rare metal deposits have been discovered in Narenwula area of Inner Mongolia, with high metallogenic potential. However, there are still many controversies about the chronology and genesis of Narenwula granite. LA-ICP-MS zircon U-Pb dating and geochemical analysis have been carried out to determine the age and genetic type of the Narenwula granite. The U-Pb dating results show that the medium-coarse biotite monzogranite and porphyritic monzogranite were emplaced in the Early Cretaceous, at (142.1±1.0)Ma and(142.3±1.2)Ma, respectively. Its diagenetic age is basically consistent with the ages of the extensive regional granite emlacement in the Late Jurassic-Early Cretaceous period. Whole-rock geochemistry shows that the granite is characterized by high silica(SiO2=73.69%-76.67%)and alkali(Na2O+K2O=8.40%-8.80%), but low P2O5, MgO, FeOT, CaO, and REE. The rocks have high LREE/HREE ratios(LREE/HREE=6.23-14.28) and marked negative Eu anomalies (δEu=0.20-0.36). They are obviously enriched in Zr, Hf, Rb, and Th, but strongly depleted in Ba, Sr, P, and Ti, and slightly depleted in Nb. The granite is high-K calc-alkaline and weakly peraluminous. Based on the characteristics of mineralogy, petrology and geochemistry, we concluded that the granite belongs to highly-fractionated I-type. Considering the structural features and regional geological background, we inferred that the Narenwula granite in the northern margin of the North China Plate was formed in the Early Cretaceous within-plate extensional setting. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics and Development Pattern of Pre-Mesoproterozoic Carbonate Subduction Reservoirs in the Qiaogu Area of the Tabei Uplift LIU Qian, FAN Tailiang, GAO Zhiqian, ZHANG Tonghui, MA Xiaoxuan, WEI Duan, LU Xinbian Geoscience    2022, 36 (05): 1391-1402.   DOI: 10.19657/j.geoscience.1000-8527.2022.048 Abstract （217）   HTML （5）    PDF（pc） （12322KB）（291）       Knowledge map    Save The buried hill formation of the pre-Mesozoic in Qiaogu area is the key area for the breakthrough of oil and gas exploration in Tabei Uplift, Xinjiang.The buried hill strata in this area are deep and complex in distribution, the reservoir is highly heterogeneous and strongly transformed by late fluid activity, and the law of oil and gas enrichment is unclear, which seriously restricts regional oil and gas exploration and target selection.In order to find out the characteristics of buried hill reservoir and the main controlling factors of reservoir development and establish the reservoir development model, the reservoir characteristics and controlling factors were systematically studied by using core, drilling and logging data and seismic data.The results show that the pre-Mesozoic reservoir lithology in Qiaogu area is mainly composed of three types: crystalline dolomite, siliceous dolomite and granular dolomite.The reservoir space is dominated by fractures, followed by dissolved pores, and locally developed karst caves.The physical properties of different lithofacies are obviously different. Fine silty dolomite, calcareous silty dolomite and sand-clastic micritic dolomite reservoirs are well developed, and the reservoir matrix has good physical properties.Micritic dolomite and siliceous dolomite are relatively compact and non-reservoir with poor physical properties.Based on the above research, the reservoir development model of the inner buried hill in Qiaogu area is extracted, that is, the reservoir development is mainly controlled by lithofacies, faults and burial-hydrothermal interaction, among which lithofacies is the material basis of reservoir development, faults are the key factors of reservoir development, and burial-hydrothermal transformation of reservoir development is superimposed.Compared with the reservoir unit characteristics of the target strata, there are five sets of small development strata in the upper member of the Xiaerbulak Formation, among which the first, third and fourth development strata have good reservoir physical properties and reservoir-cap combination, which are the preferred key targets for future oil and gas exploration and target areas. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics of Stromatolites and Its Significance in Depositional Environment Reconstruction of the Mesoproterozoic Longjiayuan Formation (2nd Member), Western Henan LI Qianqian, ZHENG Deshun Geoscience    2023, 37 (04): 845-857.   DOI: 10.19657/j.geoscience.1000-8527.2022.023 Abstract （152）   HTML （27）    PDF（pc） （12773KB）（281）       Knowledge map    Save Stromatolites recorded the life activities of early environment, cyanobacteria and microbial community, and their growth morphology was influenced by the sedimentary environment, which is of great significance for the paleo-environmental reconstruction. Stromatolites from the Longjiayuan Formation (2nd member)of the Mesoproterozoic Guandaokou Group in western Henan have various morphological types and concentrated in distribution, which is a typical area for stromatolites development. The distribution of stromatolites is closely related to global events, geochemical environment of the Precambrian ocean and the development of microbiolites, yet detailed research is still lacking. Based on this, we conducted a systematic field investigation and petrological examination on the microbialite structure on these stromatolites, studied the macroscopic and microscopic characteristics of the stromatolites, established the sedimentary environment evolution and sedimentary model, and compared with the stromatolites from other areas. The results show that the macroscopic morphology of the stromatolites can be divided into horizontal laminae, ripple, hilly, cone, and column. Microscopically, the stromatolites are light and dark laminae, with few ooids, spherular and detrital materials locally. The shape and scale of stromatolites are closely related to the hydrodynamic conditions and water depth. Horizontal laminated stromatolites were developed in the intertidal zone, whilst corrugated and mound stromatolites were developed in the intertidal high-energy zone and low-energy zone. Meanwhile, cone and columnar stromatolites were developed in the subtidal zone. Our comprehensive analysis shows that our stromatolite samples were formed in a tidal-flat environment, and were influenced by the sedimentary evolution process of intertidal, subtidal and intertidal zones. It is beneficial to analyze the Early Mesoproterozoic development environment of microbiolites in the southern margin of North China. Besides, we compared our results with the sedimentary environment of microbiolites in Jixian area (northern margin of North China), in order to explore the relationship between marine environment, atmospheric environment, and microbiolites around the North China Craton. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Advances on the Understanding in the Emeishan Mantle Plume and Dynamic Mechanism of the Permian Sichuan Basin Formation SUN Ziming, BIAN Changrong, LIU Guangxiang Geoscience    2023, 37 (05): 1089-1099.   DOI: 10.19657/j.geoscience.1000-8527.2023.043 Abstract （139）   HTML （18）    PDF（pc） （4559KB）（257）       Knowledge map    Save In recent years, significant research progress has been made on the Emeishan Large Igneous Province (ELIP) and its genetic mechanism of mantle plume, but the scope of the mantle plume on the Sichuan Basin and the dynamic mechanism for the Permian sedimentary basin formation remain unclear.Based on a number of literature research and recent studies, and the idea that deep mantle activity controls the evolution of crustal surface system, the characteristics of Emeishan LIP and its deep geology are systematically reviewed.It is recognized that the mantle plume is the dominant factor that induces the large-scale eruption of the Emeishan basalts and formed the LIP, and has direct influence on some parts of the Sichuan Basin, which is manifested by the differential denudation of the top Middle Permian Maokou Formation.This was likely caused by the upwelling of mantle plume and its control on the Permian sedimentation and sedimentary facies distribution in the central-southern part of the basin.Formation of the extensional troughs, and the alternating high-and-low sedimentary-tectonic framework in the central-northern Sichuan Basin during the Permian to Early Triassic may have been mainly controlled by the extension of the southern Qinling Ocean. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Deformation Characteristics and Evolution of the Eastern Xiangfan-Guangji Fault Zone ZHU Qingbo, CHENG Wanqiang, ZHOU Quan Geoscience    2022, 36 (03): 755-769.   DOI: 10.19657/j.geoscience.1000-8527.2021.142 Abstract （578）   HTML （124）    PDF（pc） （12716KB）（254）       Knowledge map    Save The Xiangfan-Guangji fault zone(XGF) is a boundary fault separating the Dabie orogen and the foreland fold-thrust belt on the northern Yangtze cratonic margin. Its geometry, kinematics and structural evolution characteristics have recorded the collision, assembly and interaction between two tectonic units in the north and south. Based on field investigation, structural and geochronological analyses, and combined with published regional geological and geophysical data, we considered that the eastern XGF is characterized by a “crocodile mouth” offset structure of deep south-directed thrust and shallow north-directed thrust, which differs significantly from the structural deformation style and sequence of the western XGF. The eastern part of the middle Yang-tze block is controlled by the N-S-directed tectonic system. Subduction of the northern Yangtze cratonic margin beneath Dabie oregen may have extruded the orogen from north to south. The nappe structure may have affected the Ruichang area, and the shallow thrust nappe from south to north may have affected the vicinity of Meichuan. The two structures are likely connected in the Qichun-Wuxue-Xishui area in the eastern XGF. The XGF has undergone various structural deformation stages, including the N-S-directed thrust nappe ductile shearing (end T2), Early-Middle Yanshanian shallow bipolar offset detachment (J1-3), Late Yanshanian normal faulting (K1-2), and minor early Xishanian thrusting (E1) from north to south. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Tectonic Evolution of Songnan-Baodao Sag in Qiongdongnan Basin and Its Relationship with Oil-gas Reservoir WANG Kai, WANG Genhou, JIA Qingjun, ZHANG Xiao Geoscience    2023, 37 (02): 245-258.   DOI: 10.19657/j.geoscience.1000-8527.2022.057 Abstract （285）   HTML （19）    PDF（pc） （17681KB）（254）       Knowledge map    Save The Songnan-Baodao depression is an important exploration area with great oil-gas exploration and development potential in the Qiongdongnan Basin (after the Yacheng-Lingshui Depression), and its tectonic evolution, tectonic style and prototype basin restoration are of great significance to understand the oil and gas accumulation regularities. Based on seismic data interpretation, we used 2DMove software to analyze the tectonic evolution period and the spread regularities of tectonic patterns of the Songnan-Baodao depression, and restored the characteristics of Paleogene prototype basins. The results show that the tectonic-sedimentary evolution of the Songnan-Baodao depression can be divided into six stages in three periods (pre-rift, syn-rift and post-rift), and the structural styles comprise three major categories and 14 sub-categories of simultaneous deformation styles, and simultaneous style and multistage style assemblages. Eight dustpan-like fault deposits were recovered in the local Paleogene prototype basins, with sediment thickness of 3,000-6,000 m. Preservation status of the three types of Paleogene prototype basins in the strong, medium and weak transformation areas were identified, and the local erosion thickness exceeds 5,000 m. The oil and gas transport characteristics of the Songnan-Baodao depression are characterized by source proximal, high maturity and late accumulation, and the Songtao bulge, Lingshui low bulge and Songnan bulge at the periphery represent both the oil-gas transport directional zones and effective traps of buried-hill and nappe structure, stratigraphic lithology, and inverted anticline. accumulation match the large-scale hydrocarbon generation period, which are favorable for oil and gas exploration. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Fluvial Geomorphology of the Eastern Altyn Tagh and Its Tectonic Activity Implications LU Fang, GAO Mingxing, ZHOU Shuxian, WANG Shun Geoscience    2023, 37 (05): 1100-1109.   DOI: 10.19657/j.geoscience.1000-8527.2023.020 Abstract （103）   HTML （11）    PDF（pc） （8829KB）（249）       Knowledge map    Save The Altyn Tagh strike-slip fault zone is the major control fault at the northern margin of the Qinghai-Tibet Plateau, and plays a vital role in the Cenozoic crustal deformation of the plateau.We extracted and calculated five geomorphic indices (slope, relief amplitude, fractal dimension, hypsometric integral, and stream length gradient) of 173 sub-basins by ArcGIS software.The geomorphic indices of each sub-basin were classified into five types.Their arithmetic mean values were used as relative tectonic activity indices, in order to quantitatively analyze the topographical features and the tectonic activity intensity.We show that Altyn Tagh strike-slip fault zone is the dividing line for the relative tectonic activity intensity of the whole study area, and the relative tectonic activity index level gradually decreases from south to north, and from high to low mountai-nous areas.From the spatial distribution of the relative activity tectonic index grade, the tectonic activity in the Danghe and Yemahe River basins appears to be stronger, and the intensity gradually decreases from west to east.In addition, we combine the influence of rocks, precipitation, and tectonics on the geomorphic index.Our results show that tectonics is the main factor controlling the geomorphic development in the watershed of the Altyn Tagh strike-slip fault zone, the relative tectonic activity intensity in the watershed where the seismic point is located, the watershed on both sides of the fracture zone, and the stress transition zone are higher than those in other surrounding watersheds. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Study on Organic Petrology Characteristics of the Wufeng-Longmaxi Formation Black Shale, Sichuan Basin LIU Siyi, GAO Ping, XIAO Xianming, LIU Ruobing, QIN Jing, YUAN Tao, WANG Xu Geoscience    2022, 36 (05): 1281-1291.   DOI: 10.19657/j.geoscience.1000-8527.2022.046 Abstract （365）   HTML （8）    PDF（pc） （7415KB）（239）       Knowledge map    Save At present, there is no unified classification and definition of organic macerals in the Wufeng-Longmaxi Formation black shale, which made it difficult for regional shale gas exploration and evaluation. In this study, organic macerals in the Wufeng-Longmaxi Formation black shale from the Sichuan Basin were identified and summarized via optical microscopic observation of polished blocks and organic geochemistry (TOC, δ13Corg), and their origins and organic matter types were determined. Our results show that organic macerals are mainly composed of the marine vitrinite, sapropelinite, organic zooclast and secondary groups. Among them, marine vitrinite group consists of round-/rod-shaped structureless vitrinite, and displays strong light reflection, but it is only locally distributed. The sapropelinite group is mainly composed of structureless sapropelinite, and is widely developed in organic-rich shale, which is the product of algal materials that underwent geological processes of thermal degradation. The organic zooclast group includes graptolite epidermis, chitinozoans and radiolarians. Meanwhile, the secondary group is composed of secondary bituminites, which is widely developed in matrix porosity of shales and is amorphous. The sapropelinite and secondary groups are the major types of organic macerals in the shales of Wufeng-Longmaxi Formation, whereas organic zooclast and marine vitrinite groups are less common. The organic matter type of studied shales is predominately type Ⅰ-Ⅱ1 kerogen. Moreover, the relative contents of sapropelinite and secondary groups increase, and organic matter type tends to oil-prone, contributing to their greater potentials of hydrocarbon generation. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geoscience    2022, 36 (03): 754-754.   Abstract （126）      PDF（pc） （2045KB）（237）       Knowledge map    Save Related Articles | Metrics | Comments（0）

Select

Route Planning and Ponder of Geoscience Study Travel in Hualong County, Qinghai Province LI Junlei, ZHANG Xujiao, WANG Yifan, ZHANG Xiangge, WANG Chongge, YUAN Xiaoning, LIU Xinlan, WANG Kaiya, RAO Haoshu, LIU Jiang, QIN Yuan Geoscience    2023, 37 (05): 1411-1422.   DOI: 10.19657/j.geoscience.1000-8527.2023.113 Abstract （94）   HTML （11）    PDF（pc） （12118KB）（230）       Knowledge map    Save Geoscience study travel is a new engine to utilize the resources of geological heritage to carry out the popularization of geoscience, which in turn leads to geotourism. Yet, due to the fact that the guiding ideology and methodology of study route planning are still unclear, there are problems such as limited study objects, superficial course contents, insufficient scientific inquiry, and emphasizing on touring but not on studying, etc. in geoscience study in general. Hualong County in Qinghai Province, which is located in the upper reaches of the Yellow River, preserving significant geological heritage such as the convergence of Rodinia supercontinent, the subduction and closure of the Proto-Tethys Ocean, the uplift of the Tibetan Plateau and the Yellow River evolution, etc., which is a unique resource to carry out geoscience study travel. This paper discusses the design ideas of geoscience study planning from the guiding ideology, scientific questions and supporting facilities, taking Huarong County as an example.Based on the detailed field geological survey, the characteristics, types, distribution and scientific value of geological heritage in Hualong County have been systematically researched and deeply excavated. Taking the Early Paleozoic Ophiolite Suite in Laji Mountain, Xining Group-Hualong Complex Angular Unconformity, Danxia landform, Red Soil Forest landform and paleoseismic dammed-lake as the key points of the study, we have planned out the Lamu Gorge-Heshijia “the Meeting of one Billion Years”, Ahetan Village-Gongbo Gorge “Flowing Water-the Sculptor of Nature”, Keba Village-Jinyuan Township “Double-edged Sword of Neotectonic Movement”, Yaoshuiquan-Ansiduo Township “Conversion of Sea and Land with Ophiolite”, Xiaqiong Temple-Gangshan Mountain “the Winding Yellow River, the Forest Sea of Plateau”, a total of five geoscience study routes. It also proposes the methods of planning and designing geoscience study routes oriented by geoscience questions and guided by the earth system view and the theory of harmonious coexistence between man and nature. It can provide a scientific basis for the development of geotourism in Hualong County, and also has a certain reference value for the development of geoscience study in other areas. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Division and Geological Evolution of Pre-Nanhua Tectonic Units in Qaidam Basin and Its Northern and Southern Margins ZHANG Jinming, WANG Bingzhang, FU Yanwen, TIAN Chengxiu Geoscience    2022, 36 (05): 1193-1205.   DOI: 10.19657/j.geoscience.1000-8527.2022.040 Abstract （450）   HTML （22）    PDF（pc） （4673KB）（229）       Knowledge map    Save Based on the comprehensive research and regional survey in recent years, we have studied the material composition, metamorphism and deformation of the Pre-Nanhua period in the Qaidam Basin and its northern and southern margins. Tectonic units in the Qaidam basin and its northern and southern margins are divided into five ancient land mass (i.e., Mesoproterozoic Huangyuan continental block, Neoarchean-Paleoproterozoic Quanji continental block, Paleoproterozoic Dakendaban continental block, Paleoproterozoic Jinshuikou continental block, and Mesoproterozoic Ningtuo continental block) and eight secondary structural units. The geological characteristics of each tectonic unit are discussed, and the geological process and evolution of the Qaidam Basin and its northern and southern margins in the pre-Nanhua geological stage are reconstructed. Compiling the key geological events in the region, tectonic evolution of the Qaidam basin and its northern and southern margin includes Neoarchean continental nuclei formation, Paleoproterozoic early rifting, the Late Paleoproterozoic-Mesoproterozoic ancient land mass formation, Early Neoproterozoic mid-stage intracontinental rifting, the Early Neoproterozoic continental convergence. Six Neoproterozoic continental riftings were in response to the global Kenorland, Columbia and Rodinia supercontinental cycle events. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Study on the Intrusive Ages of the Granites and Metallogenic Age from Zhongteng Copper Deposit, Pinghe, Fujian Province REN Chenghao, SHE Hongquan, KE Changhui, SUN Yandong, ZHOU Qunmao, JIAO Tianlong, LI Baoliang Geoscience    2022, 36 (06): 1447-1464.   DOI: 10.19657/j.geoscience.1000-8527.2022.06.01 Abstract （299）   HTML （23）    PDF（pc） （8509KB）（227）       Knowledge map    Save Zhongteng Cu deposit, located in the Shanghang-Yunxiao tectonic magmatic metallogenic belt on the southeast margin of Cathaysian Plate, is a magmatic hydrothermal deposit. Geochemistry of the three types of granitic intrusive rocks from the ore deposit indicates that they belong to high potassium calc-alkaline series, characterized by high K2O, low Si and low TiO2; some rocks belong to peraluminous. Analysis on REE and trace elements has shown the granites are enriched in light rare earth elements, have weak negative europium anomaly, enriched in large ion lithophile elements (K, Rb, Th, etc.), and depleted in high field strength elements (Nb, Ta, Ti, etc.). Zircon LA-ICP-MS dating of the granites gives (103.5±0.4) Ma, (102.2±0.4) Ma, (103±0.4) Ma,respectively. Zircon εHf(t) values of granites is between -2.9 and 2.0,the two-stage model ages (TDM2) are 1.04-1.35 Ga. Re-Os isotopic dating on the molybdenite samples from the ore body obtained an isochronic age of (105±2.5) Ma, indicating that the formation of Zhongteng copper deposit is mainly related to intrusive rocks formed at late stage of Yanshan period. Based on this study and newly other study results, it is reasonably to considered the granites at Zhongteng copper deposit belong to I-type, its formation and related mineralization were related to subduction of the Paleo-Pacific Plate occurred at southeast coastal area during late Early Cretaceous Period (110-90 Ma). Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Stable Isotope Characteristics of Geothermal Water and Calculation of Geothermal Reservoir Temperature in the Erdaoqiao Area of Kangding in Sichuan Province JIANG Zhe, ZHOU Xun, CHEN Binghua, TAO Guangbin, LI Zhuang, CAO Ruwen, SUI Liai Geoscience    2022, 36 (04): 1183-1192.   DOI: 10.19657/j.geoscience.1000-8527.2022.04.20 Abstract （298）   HTML （6）    PDF（pc） （4925KB）（222）       Knowledge map    Save In order to study the stable isotope characteristics of geothermal water and geothermal reservoir temperature in the Erdaoqiao area near Kangding in Sichuan, five hot springs including the Erdaoqiao hot springs (SC107 and SC107-2), Kangbarenjia hot spring (SC107-3), the flowing hot water well (SC107-4) and spouting hot water well (SC107-5) are investigated. The Yalagou fault and the Yala river valley control the occurrence of the hot springs in the study area. The water temperature of the hot springs in the study area ranges from 33.2 ℃ to 46 ℃, and pH value, from 6 to 6.5. The hot springs are of medium-low temperature. The stable isotope compositions of hydrogen and oxygen of the hot springs indicate that the hot water in the study area is of meteoric origin. Based on the altitude effect and temperature effect, the elevations of the recharge areas of the hot springs are estimated to be about 3 000-4 500 m, and the temperature of the recharge areas range from -3.5 ℃ to -0.3 ℃, indicating that the hot springs may be recharged partly by snow-melting water. The Na-K-Mg triangular diagram shows that the hot water in the study area is the unmature water, so it is impossible to calculate the temperature of geothermal reservoirs with the cation geothermometry. The temperature of the geothermal reservoir in the study area ranges from 65 ℃ to 75 ℃ by using the SiO2 geothermometry, multi-mineral saturation index method and Fix-Al method. The hot springs in the study area are recharged by precipitation and snow-melting water at the eastern part of the Paoma mountain and the western part of the Nongge mountain. The groundwater flows along the Daxue mountain-Nongge mountain fault and the Paoma mountain fault and undergoes a deep circulation. After heated by heat flow, the thermal groundwater rises and emerges as hot springs in the Yala River valley and near the Yalagou fault. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Spatial Prediction of Surface Soil Ore-forming Elements Based on Machine Learning: Taking Rare Metal Rubidium as An Example DAI Liangliang, NIE Xiaoli, GUO Jun, GONG Hao, WU Huanhuan, ZHANG Tao, TANG Yuanyuan, MAO Cong, PENG Zhigang, HE Can Geoscience    2022, 36 (03): 972-978.   DOI: 10.19657/j.geoscience.1000-8527.2022.03.17 Abstract （309）   HTML （11）    PDF（pc） （4325KB）（220）       Knowledge map    Save Mass geochemical data of surface soil have been obtained in recent years with the development of geochemical surveys of land quality. However, there is an obvious defect in the dataset of 1∶50 000 large-scale surface samples, i.e., the lack of ore-forming elements. In view of the important role of ore-forming elements in the prospecting of mineral resources, this article attempts to provide a supplementary plan based on existing data. Taking the rare metal rubidium as an example, 2,548 groups of 1∶250 000 small-scale surface soil data in the same area were divided into two groups randomly using the random forest algorithm according to the ratio of 8∶2, with 80% of the data for model training and 20% of the data for model verifying. The combination of variable importance metric ranking and learning curve construction was used to select 8 elements (K, B, Ni, V, Zn, As, Co, Cu) as predictors. The goodness of fitness(R2)of the model to the training data and test data reached 0.983 2 and 0.895 6, respectively, indicating that the optimal method of predictor variables is effective. Subsequently, the above-mentioned predictive variable data of 1∶50 000 surface soil was imported into the model as input variables, and the predicted Rb element content was obtained. The predicted results were in line with the actual characteristics. This study indicating that it is feasible to introduce the big data machine learning random forest algorithm into the spatial quantitative prediction of surface soil geochemical element content, and the service application dimension of land quality geochemical data can be further expanded. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics, Genesis and Evolution of Daigu Landform in Yimengshan UNESCO Global Geopark CAI Yinlu, WU Fadong, HAN Jinfang, HUANG Zhen, ZHOU Ying, LIU Baoyin, CHEN Yangyang Geoscience    2023, 37 (04): 1065-1074.   DOI: 10.19657/j.geoscience.1000-8527.2023.085 Abstract （539）   HTML （8）    PDF（pc） （12188KB）（218）       Knowledge map    Save The Yimengshan UNESCO Global Geopark (UGGp) is the origin of the “Daigu Landform”. Through field investigation of the characteristics of Gu landform, based on the measurement of river valley stratigraphy and profiles, and using the OSL dating of the river terrace to calculate the cutting rate, the formation time of Daigu Landform has been determined. The results show that the geomorphological features of the Daigu Landform are related to the strata lithology of the Gu body. Daigu Landform is a type of mesa structure, with a flat top, steep margin and gentle slope. Gu body is mainly composed of two strata with different lithologies: The top comprises Cambrian limestone with strong weathering resistance but develops many joints, while the Gu body with weak erosion resistance is dominated by mudstone and siltstone. We estimated that the formation time is about 1.77 Ma by using the erosion rate, based on the dating results of the river terrace. The Daigu Landform formation and evolution can be divided into four main stages: (1) the material was formed in the Early Cambrian; (2) tectonic uplift, and the strata gradually exhumed and the shaping stage began; (3) long-term weathering and denudation of various external forces, such as surface water that gradually created the mature Daigu Landform; (4) the landform ended its development when the upper limestone collapsed. The systematic study of the Daigu Landform has great importance in understanding the Daigu Landform and its scientific value, which also contributes to the spreading of geoscience knowledge of UGGps. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Controlling Factors and Types of Geomorphologic Landscapes in Danxiashan UNESCO Global Geopark of China GUO Fusheng, LING Yuanyuan, CHEN Liuqin, ZHOU Wanpeng, LI Hongwei, CHENG Liangkai, WU Zhichun, LI Guangrong, GUO Zhen, LI Bin Geoscience    2023, 37 (06): 1665-1679.   DOI: 10.19657/j.geoscience.1000-8527.2023.099 Abstract （39）   HTML （11）    PDF（pc） （50465KB）（215）       Knowledge map    Save Danxiashan UNESCO Global Geopark is characterized by well-developed Danxia landscape in humid climate of South China, where geomorphologic features and genetic analysis of individual landforms have received much attention in previous studies. However, the controlling factors of landscape development across the Danxia Basin remain poorly understood, and the relationship between fault systems and peaks is yet to be well recognized. In this study, methods such as field survey, rock hardness measurement, remote sensing interpretation of liner structures, and experimental analysis of rock samples were used to illustrate the roles of lithology, depositional facies, and tectonic uplift and dissection in shaping the landscape evolution and to propose a gene-tic and morphologic classification of Danxia landscape. The Upper Cretaceous continental red beds in the Danxia Basin consist of the Changba and Danxia formations. The Changba Formation has a larger outcrop area, forming gentle low hills, while the Danxia Formation is concentrated and characterized by well development of cliffs, representing the typical Danxia landscape. The Danxia Formation is composed of coarse clastic rocks of alluvial fans and eolian sandstones, and is featured by having great thickness, tight cementation, high density and hardness, and being resistant to weathering. In contrast, the Changba Formation consists dominantly of fine-grained muddy clastic rocks deposited in river and lake environments, which are less resistant to weathering and cannot support Danxia landscape with cliffs. The Himalayan tectonic movement likely caused the overall uplift of the Danxia Basin, which resulted in the formation of a series of NE-trending faults and NNE-, NW-, and nearly EW-trending joints. The fracture surfaces may have facilitated subsequent weathering and erosion, producing prominent cliffs, reticulated valleys, and peculiar peaks and rocks. The Danxiashan area is in a subtropical humid climate, where weathering, collapse, water erosion, and karst processes are the main landscape-shaping external forces. Accordingly, the genesis of Danxia landscape is classified into five categories, i.e., collapse-scour, collapse-accumulation, weathering-denudation, river erosion, and dissolution-sedimentation types. The cliff development is a key element of Danxia landscape, and the different combinations of cliff quantities and types formed hills and gorges. Based on these features, the morphological types of Danxia landscape in Danxia-shan are divided into six major categories and twenty-two specific types. This paper has theoretical significance and practical values because it provides a better understanding of the formation processes of Danxia landscape in humid climate, and foundational materials for construction of national park, scientific mountain, and geoscience study travel. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Dynamic Model Analysis of Formation and Evolution of the South China Sea LIU Chen, LI Jianghai, WANG Zhichen Geoscience    2023, 37 (02): 259-269.   DOI: 10.19657/j.geoscience.1000-8527.2022.033 Abstract （148）   HTML （15）    PDF（pc） （7680KB）（212）       Knowledge map    Save The South China Sea is located in the convergence zone of three tectonic plates. Due to the wide distribution and complex geodynamic background, its genesis and dynamic model are still controversial. Based on geological data, gravity, and magnetic data from the South China Sea, the structural characteristics of the South China Sea are analyzed in plane and profile. Accordingly, numerical simulation shows that the weaker lower crust has decoupled from the crust-mantle, and the rift has migrated to one side. Due to the insufficient magmatic heat supply, the upwelled mantle has cooled and stagnated. The new magma supply may have jumped to the opposite direction and formed a new spreading center. The weak rheological lower crust and high spreading rate may have together controlled the southward ridge migration. We analyze and summarize the existing dynamic models of the South China Sea. Based on tectonic interpretation and numerical simulation, we concluded that the South China Sea formation was mainly affected by three factors: the collision between the India-Australia and Eurasia plates, the subduction drag of the Proto-South China Sea, and the upwelling of the deep mantle. The tectonic stress field in the South China Sea was controlled by the Indo-Australia-Eurasia collision and the subduction and drag of the Proto-South China Sea, and the magma migration was controlled by the deep mantle upwelling. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Saturation Calculation Model With Variable Rock-Electrical Parameters for Tight Sandstone Reservoirs: A Case Study of the Shihezi Formation (8th Member) in Western Sulige Gas Field LU Junhui, ZHANG Xiaoli, YANG Zhen, LI Yajun, WANG Xiaolin, ZHAO Xi Geoscience    2022, 36 (04): 1131-1137.   DOI: 10.19657/j.geoscience.1000-8527.2021.183 Abstract （259）   HTML （5）    PDF（pc） （5324KB）（210）       Knowledge map    Save Tight sandstone reservoirs are one of the major regions for oil and gas exploration. Due to the characteristics of low porosity and permeability, complex pore structure, and strong heterogeneity in rock electrical parameters, logging interpretation process for tight sandstone reservoirs is different from that of conventional reservoirs. When interpreting tight sandstone reservoirs with the Archie formula, strong heterogeneity would lead to changes in the rock electrical parameters a, b, m and n with different reservoirs. In this study, a saturation model is established by using the variable rock electrical parameters for the tight sandstone reservoir in the Shihezi Formation (8th member) in the western Sulige gas field. According to the rock-electrical experiment on 25 cores, we found that the relationship between cementation coefficient m and lgϕ is a quadratic function, the relationship between m and lithology coefficient a is a power function, and the irreducible water saturation Swb has major influence on the saturation index n. Therefore, based on the analysis of porosity, irreducible water saturation and pore structure index, the saturation model with variable rock electrical parameters is established by integrating the various influence factors. The results show that the accuracy of this method is higher than that of the traditional Archie formula, which is effective for interpreting complex pore structure sandstone reservoirs. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochemical Characteristics and Influencing Factors of Germanium in Surface Soil of Lishui District, Nanjing City ZHOU Mo, LIANG Xiaohong, ZHANG Ming, WEN Bangyong, TANG Zhimin, ZHAN Long Geoscience    2023, 37 (01): 217-226.   DOI: 10.19657/j.geoscience.1000-8527.2023.01.23 Abstract （277）   HTML （15）    PDF（pc） （5884KB）（208）       Knowledge map    Save Germanium (Ge) is an essential trace element for life and has extensive health care effects on the human body. It is valuable to develop Ge-rich soil, whereas the research on soil Ge is still insufficient in China.Based on the results of land quality geochemical survey in Lishui district, Nanjing, the content and spatial distribution characteristics of Ge in surface soil and the influence of geological background on soil Ge were studied in this paper.The results revealed that the average Ge content in surface soil of Lishui district was 1.40 mg/kg, which was mainly controlled by geological background and its spatial distribution was highly consistent with geological background.The high value area of Ge content is mainly the outlying area of J3d1-2, and the lithology is mainly trachyandensite and andesite, while the Quaternary sediment distribution area has relatively low Ge content.There was no significant relationship between Ge and pH value in the soil, there was a certain negative correlation with organic matter content, and an obvious positive correlation with Cr, Co, Ni and As. The Ge-rich soil area in the study area is 84.18 km2, accounting for 10.84% of the total area of the whole region, and there is basically no Ge deficient area in the whole region.In this paper, the content, spatial distribution and influencing factors of Ge in surface soil of Lishui district, Nanjing were discussed, which can provide basic data for the ecological geochemical study of Ge in soil in China, and have guiding significance for the scientific development and utilization of Ge-rich soil resources. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics and Scientific Values of “Canyon and Danxia” Landform in Hualong County, Qinghai Province LIU Xinlan, ZHANG Xujiao, LI Junlei, WANG Yifan, ZHANG Xiangge, YUAN Xiaoning, WANG Kaiya, WANG Chongge, LIU Jiang, HOU Engang Geoscience    2023, 37 (01): 233-244.   DOI: 10.19657/j.geoscience.1000-8527.2023.031 Abstract （501）   HTML （34）    PDF（pc） （12319KB）（197）       Knowledge map    Save “Canyon and Danxia” is a composite landscape formed by both internal and external geological processes, and has great landscape and scientific value. The Lamu river in Hualong county (Qinghai Province) is a primary tributary of the Yellow River, where typical angular unconformity and Danxia landform are developed. This makes Hualong a suitable area for studying the Qinghai-Tibetan Plateau uplift and the Yellow River evolution. Aiming at elucidating its morphology, genesis, and chronology, this field study focuses on the rock formation, strata and tectonic setting of “Canyon and Danxia” landform. We systematically concluded the driving force and formation processes of the landscape in the Lamu canyon, and discussed its implications to the Qinghai-Tibetan Plateau uplift and the Yellow River evolution. The Lamu canyon is composed of the Neoproterozoic Hualong Complex gneiss (~900 Ma) and Paleogene Xining Group red glutenite (~54 Ma) with an angular unconformity. The Danxia landform in the canyon was developed when the Qinghai-Tibetan Plateau started uplifting at 8 Ma. After the Hualong Basin was cut by the Yellow River at 1.1 Ma, the canyon developed “Canyon and Danxia” landform via continuous river incision and gravitational collapse. The canyon is precipitous and the Danxia landform is lifelike, which are typical, unique and rare national-class geoheritage. It has important research value on the uplift of the Qinghai-Tibetan Plateau, the evolution of the Yellow River, and the Cenozoic climate and environment. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Development and Evolution Characteristics of Strike-slip Faults in Tarim Basin and Its Geological Significance: A Case Study of FⅠ17 Fault in Fuman Oilfield LIU Qiang, ZHANG Yintao, CHEN Shi, SONG Xingguo, Li Ting, KANG Pengfei, MA Xiaoping Geoscience    2023, 37 (05): 1123-1135.   DOI: 10.19657/j.geoscience.1000-8527.2023.058 Abstract （99）   HTML （15）    PDF（pc） （16110KB）（195）       Knowledge map    Save The strike-slip fault in the platform Tarim basin has the characteristics of “controlling reservoir, controlling reservoir and controlling wealth”, but because it is developed in ultra-deep layer and its activity intensity is low, the fine analysis and evolution characteristic analysis of the fault is the focus and challenge of the current research.To deepen the fine analysis process of strike-slip fault structure and explore the geological significance of fault activity, we took FⅠ17 fault as a case study.Based on the new high-precision 3D seismic data in the Fuman oilfield, combined with a variety of seismic attributes such as coherence, maximum likelihood and reservoir amplitude change rate, we analyzed the spatial distribution regularity, activity characteristics and evolution process of faults, and the characteristics of fault control and storage in combination with the reservoir development characteristics.Based on the reconstruction of the local structural characteristics of the Precambrian basement, the development mechanism of fault plane strike migration is preliminarily analyzed.The results show that the local FⅠ17 fault plane has changed many times and its strike shifted counterclockwise from south to north.Based on the changing characteristics of the fault strike, the fault can be divided into three segments: North (NE8°), middle (NE33°) and south (NE50°).The fault has the characteristics of vertical delamination defor-mation.According to the fault deformation characteristics, it can be divided into the deep structural deformation layer characterized by vertical strike-slip (below TO3t), and the shallow structural deformation layer with echelon normal fault (above TO3t).The fault has the characteristic of “stratified flowering” in the deep structural deformation layer, and several flower-like structures are developed vertically, which are mainly distributed near the bottom of the Upper Cambrian (T∈3) and the top of the Yijianfang Formation (TO3t).Three groups of echelon normal faults are developed vertically in the shallow structural layer, which are distributed in TO3t-TS, TS-TC and TC-TT from bottom to top.The fault evolution is likely multi-stage, and the evolution can be divided into five stages: early Caledonian, middle Caledonian Ⅰ, middle Caledonian Ⅲ, late Caledonian-early Hercynian, and middle-late Hercynian.The Precambrian basement rift structure likely affected the development and connection of the overlying strike-slip faults, resulting in the fault plane offset. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Magnetic Anomaly Inversion Based on Convolutional Neural Network XUE Ruijie, XIONG Jie, ZHANG Yue, WANG Rong Geoscience    2023, 37 (01): 173-183.   DOI: 10.19657/j.geoscience.1000-8527.2021.150 Abstract （222）   HTML （19）    PDF（pc） （11851KB）（192）       Knowledge map    Save To resolve the problems of traditional inversion methods, such as initial model dependence and long calculation time, we proposed a magnetic anomaly inversion method based on convolutional neural network. With this method, a number of magnetic anomalous body models were designed to perform forward simulation, which generated various sample data-sets. Subsequently, a new VGG magnetic anomaly inversion network (VGGINV) was designed based on the classic convolutional neural network VGG-13. After that, the sample data-set was used to train the network and optimize the network parameters. Finally, inversion experiment was performed based on this theoretical model and actual field data. The experimental results show that the proposed method can accurately invert the position and magnetization of magnetic anomaly, with strong learning ability and certain generalization ability, and can effectively solve problems in magnetic anomaly data inversion. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Application of GF-5 Satellite Hyperspectral Data to Uranium Ore Geological Prospecting in Longshoushan Area in Gansu Province FENG Bo, DUAN Peixin, CHENG Xu, LU Huixiong, LI Ruiwei, ZHANG En, WANG Bing Geoscience    2022, 36 (06): 1594-1604.   DOI: 10.19657/j.geoscience.1000-8527.2022.06.14 Abstract （453）   HTML （14）    PDF（pc） （16126KB）（192）       Knowledge map    Save Hyperspectral remote sensing technology is widely used in geological prospecting. Gaofen-5 (GF-5 for short) is China’s first hyperspectral comprehensive observation satellite, which has hyperspectral resolution remote sensing data of 330 spectral segments. To improve our understanding, it is necessary to explore the application effect and potential of GF-5 space hyperspectral remote sensing technology to unveil the relevant processes in uranium geological prospecting. This study used hyperspectral data in Longshoushan metallogenic belt, Gansu Province, to carry on hyperspectral data processing and alteration information extraction study. GF-5 hyperspectral band repair was innovatively realized. By constructing standard spectral library and diagnostic spectrum, MNF algorithm, PPI algorithm and SAM spectral angle mapping technology were used to complete alteration mineral end-member extraction and spectral matching. We finally achieved the extraction of albite, calcite, quartz, chlorite, hematite and kaolin alteration minerals in our study area. Comprehensive regional uranium ore-forming geological background, by conducting ground spectrum measurement and field investigation, on the basis of accuracy verification alteration, we analyzed the space hyperspectral alteration information and metallogenic regularities, built the regional prospecting orientation model, at the same time three prospecting prediction areas were delineated, and good prospecting results were achieved. This paper provides reference for the application of GF-5 hyperspectral remote sensing in geological prospecting. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochemical Characteristics and Source Analysis of Heavy Metals in Soils of Eastern Yinan, Shandong Province LIU Tong, LIU Chuanpeng, KANG Pengyu, ZHAO Xiufang, DENG Jun, WANG Kaikai Geoscience    2022, 36 (04): 1173-1182.   DOI: 10.19657/j.geoscience.1000-8527.2022.04.19 Abstract （410）   HTML （17）    PDF（pc） （5528KB）（192）       Knowledge map    Save In order to present the status of soil heavy metal pollution in Yinan County, Shandong Province, 4,779 surface soil samples were collected systematically in this area, and the concentration of Cd, Hg, Pb, As, Cr, Ni, Cu, Zn and pH value were analyzed. The geochemical characteristics of heavy metals and possible sources have been discussed by geostatistics, multivariate statistics, spatial analysis and other analysis methods. The results show that the Hg mean value in soil is slightly higher than the background value of surface soil in Linyi city, and the respective mean values of the other seven elements are equivalent to that of Linyi. Compared with the screening value of GB 15618—2018 (soil environmental quality risk control standard for soil contamination of agricultural land), the concentration over-standard rate of eight heavy metal elements in the research area is low. But the exceeding standard multiple of the maximum value is large, that shows local point and small pieces are seriously polluted. The concentration of 8 kinds of elements in the research area shows a three-step decline from west to east. The high concentration of Cd, Pb, Zn and As in the soil are mainly controlled by natu-ral source, parent rocks, superimposed different degrees of industrial and mining transportation and agricultural activities. Cr and Ni are almost completely controlled by parent rocks. Hg and Cu are controlled mainly by the mining and smelting activities of Yinan Jinchang and Tongjing gold mine, followed by industrial and traffic emissions, agricultural manure and pesticide application. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Comparison of Washing Oil Experiment of Core Samples from Shale Oil Reservoir WANG Zhihao, ZHAO Jianhua, PU Xiugang, LIU Keyu, LI Junqian, CHENG Bin Geoscience    2022, 36 (05): 1304-1312.   DOI: 10.19657/j.geoscience.1000-8527.2022.049 Abstract （346）   HTML （8）    PDF（pc） （2694KB）（192）       Knowledge map    Save Fractures and micro-/nano-scale pores in shale reservoirs are the main occurrence space of shale oil. Efficient and non-destructive washing oil of core samples is the key to the characterization of shale pore structure and shale oil occurrence, yet there is no unified scheme currently. In this study, we investigated and summarized the common “washing oil” schemes, and selected Soxhlet extraction, rapid extraction and gas flooding + Soxhlet extraction to compare their effects on shale block samples (1 cm×1 cm×1 cm) from the Kongdian Formation (Ek2, 2nd member) in the Cangdong depression. Rock-eval pyrolysis instrument and gas chromatograph were used to compare the experimental results and the pros and cons of the three methods, by analyzing the samples before and after washing oil and the extracted soluble organic matter. The results show that the heavy hydrocarbon components in the extract increase gradually with time. It is difficult for low-porosity/-permeability shale cores to achieve ideal washing oil effect under room temperature and pressure. Heating and pressurization can improve experimental efficiency, but heavy hydrocarbons and adsorbed components would partially break down into light hydrocarbons due to prolonged high temperatures, and the S1 value would rise when the rate of decomposition is higher than that of extraction. Appropriate pressure conditions can effectively promote the washing oil rate, but the samples or its pore structures may be destroyed under the unstable pressure. We suggested to use lower pressure, room temperature or slightly higher temperature in washing oil to speed up the process, which would produce better results when combining the displacement and extraction methods. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochemical Characteristics and Prospecting on Stream Sediment Survey in Qianhongquan Area of Beishan in Gansu Province, China CHEN Shiming, YANG Zhenxi, LEI Ziqiang, KANG Weiliang, ZHANG Jing, ZHAO Qinghu Geoscience    2022, 36 (06): 1513-1524.   DOI: 10.19657/j.geoscience.1000-8527.2022.06.07 Abstract （316）   HTML （6）    PDF（pc） （10807KB）（191）       Knowledge map    Save After the regional geochemical survey and natural heavy mineral survey with the scale of 1∶200 000, a detailed geochemical survey with the scale of 1∶50 000 was implemented in Qianhongquan area of Beishan in Gansu Province, China. The sampling media in this detailed survey is stream sediments sieved between 4 and 20 meshes and 17 elements (W, Sn, Mo, Bi,Cu,Pb,Zn, Cd,Au,Ag, As, Sb, Hg, Co,Ni,Cr, Nb) were analyzed. The geochemical characteristics such as the statistical parameters of elemental concentrations, elemental assemblages based on correlation analysis and R-type cluster analysis were reported and the geochemical anomalies were determined and assessed. Based on these results of geochemical survey, four metallic prospecting areas are recognized which are Wansuishan Au metallic prospecting area controlled by the fracture zone, Heishantou Au-polymetallic prospecting area controlled by the ductile shear zone, Zhangfangshan Cu-Co-Ni polymetallic prospecting area controlled by the basic rocks, and Hongliugeda W metallic prospecting area controlled by tectonic fractures formed in acidic intrusive rocks. Furthermore, four detailed metallic targets are delineated in these prospecting areas for the future exploration works. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Carboniferous Tectono-stratigraphic Division and Basin-forming Background in the Bogda Area, Eastern Tianshan FAN Dan, LI Di, HE Dengfa, HOU Shuoqin, SUN Tiange, YANG Hao, ZHEN Yu Geoscience    2022, 36 (05): 1206-1217.   DOI: 10.19657/j.geoscience.1000-8527.2022.043 Abstract （250）   HTML （13）    PDF（pc） （9707KB）（186）       Knowledge map    Save The Bogda area experienced the evolution processes involving the Paleozoic subduction-accretion and Meso-Cenozoic multi-stage intracontinental deformation, but controversies remain regarding the Carboniferous tectonic attribute and evolutionary stages in the Bogda Mountain, which restricts further research on the late Paleozoic tectonic framework in North Xinjiang. Integrating the outcrop geology, borehole and seismic data from the Bogda Mountain and its adjacent basins, we carried on a comprehensive comparative study of the Carboniferous stratigraphic framework and magmatic characteristics in a basin-orogen scale by the basin analysis theory and method. Accordingly, we divided the Carboniferous tectonic-stratigraphic units in the Bogda area and analyzed the Carboniferous tectonic setting. Our results show that the unconformity between the Lower Carboniferous and pre-Carboniferous strata (C1/AnC) are present in the Junggar Basin and Tuha Basin adjacent to the Bogda Mountain, while the unconformities, including the Upper and Lower Carboniferous (C2/C1), and Permian and Upper Carboniferous (P/C2) ones, are commonly developed in the Bogda Mountain and its adjacent basins. Thus, the Carboniferous strata in the Bogda area are subdivided into two tectono-stratigraphic units, i.e., Lower Carboniferous and Upper Carboniferous, which reveals that the study area has undergone two major tectonic evolutionary stages. Combining the structural deformation evolution, basinal subsidence characteristics and tectonic setting, we suggested that the Carboniferous Bogda represents a back-arc basin in the subduction-related extension regime, which underwent two stages of rifting. The peripheral collisional events may have caused the later tectonic inversion for both rift basins during the late period. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Inversion of Gravity Anomaly Based on AlexNet Deep Neural Network LIU Caiyun, LI Mengdi, XIONG Jie, WANG Rong Geoscience    2023, 37 (01): 164-172.   DOI: 10.19657/j.geoscience.1000-8527.2022.079 Abstract （250）   HTML （18）    PDF（pc） （9429KB）（180）       Knowledge map    Save In order to solve the problems of traditional inversion methods, such as dependence of initial model and long time for calculation, this paper proposes a noval gravity anomaly inversion method based on AlexNet deep neural network. This method designs an Alex inversion network (AlexInvNet) for gravity anomaly inversion inspired by classical deep neural network AlexNet firstly; constructs labeled datasets by forward modeling using a large number of synthetic density models secondly; uses the dataset train the AlexInvNet thirdly; and finally inputs the gravity anomaly data to the trained AlexInvNet to obtain the inversion result directly. The inversion experimental results of synthetic models show that this method can invert the position and density of anomaly body accurately, with good generalization and anti-noise ability, better than the full connected network deep learning inversion method. The field data inversion result demonstrates that this method can solve gravity anomaly inversion problem effectively. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics and Assessment of Geoheritage of the Proposed Hualong National Geopark in Qinghai Province WANG Chongge, LI Junlei, ZHANG Xujiao, YUAN Xiaoning, ZHANG Xiangge, WANG Yifan, WANG Kaiya, LIU Xinlan, RAO Haoshu, LIU Jiang, HOU Engang Geoscience    2023, 37 (02): 512-528.   DOI: 10.19657/j.geoscience.1000-8527.2023.047 Abstract （144）   HTML （16）    PDF（pc） （15398KB）（180）       Knowledge map    Save Establishing national geopark is an effective way to protect geoheritage as well as promote ecological protection and high-quality development of the Yellow River Basin. Also, investigation and assessment of geoheritage are significant to the design and construction of geopark. Hualong county is located at the northeastern margin of Qinghai-Tibetan Plateau, and has rich Yellow River cultural relics since the river flows through the county for 168 km. But systematic research is still needed to verify if the geoheritage distributed in the county can meet the requirements of geopark. Based on the geoheritage investigation, this paper quantitatively assesses the value of geoheritage distributed in Hualong county by analytic hierarchy process (AHP),and the boundary of the proposed Hualong National Geopark is confirmed. 40 geoheritages are found in the geopark, covering 6 large categories, 9 categories and 20 sub-categories, including 2 world-class, 6 national-class geoheritages. Among them, Early Paleozoic suture zone on Mount Lajishan, as well as angular unconformity between the Xining Group and Hualong Complex, have significant scientific and global correlation value on the evolution of the Proto-Tethyan Ocean and the uplift of the Qinghai-Tibetan Plateau, separately. The result shows that Hualong county is well of various, characteristic, significant-value and well-preserved geoheritages, which have the resource natural endowment for establishing National Geopark and the potential to be listed as a UNESCO Global Geopark. This paper provides not only scientific evidence for the application and construction of Hualong National Geopark, but also references for creating the Yellow River Cultural Tourism Belt. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Progress on Metallogenic Research of Granite-related Uranium Deposits from Luzong Ore District in the Middle and Lower Reaches of Yangtze River Metallogenic Belt ZHANG Shu, ZHANG Zanzan, HU Zhaoqi, SHI Lisheng, ZHOU Taofa, WU Ming'an, DU Jianguo Geoscience    2023, 37 (06): 1435-1448.   DOI: 10.19657/j.geoscience.1000-8527.2023.083 Abstract （81）   HTML （8）    PDF（pc） （12524KB）（178）       Knowledge map    Save The Lujiang-Zongyang ore district is one of the most important ore cluster regiones in the Middle and Lower Reaches of the Yangtze River Metallogenic Belt, and is also an important uranium prospecting area in the South China Uranium Province.Systematic uranium metallogenic study would benefit the understanding of the regional metallogenic theory and uranium prospecting.In this paper, we provide a review of the geological features, uranium-bearing intrusions, magmatic and metallogenic ages, ore-forming fluids, and uranium sources of the typical uranium deposits in the Lujiang-Zongyang ore district.The uranium deposits along the NE-trending A-type granite belt are controlled by intrusive contact, faults, and interlayer structures.The uranium deposits were formed at 114-108 Ma, whereas the ore-bearing granites are A1-type and were formed at 127-123 Ma with 115-110 Ma alkali feldspar granitic stocks.The ore-forming materials were derived from the ore-bearing intrusions and wall-rocks.The ore-forming fluids were the mixture of magmatic water and meteoric water.The uranium was likely originated from the leaching of the ore-bearing intrusions during the fluid circulation, and deposited by changes in the physicochemical condition.The uranium mineralization in the Luzong basin was controlled by concealed syenite and was formed at 131-129 Ma.The ore-bearing intrusions, which provide the ore-material sources, are of shoshonitic and were formed at 131 Ma.The ore-forming fluids were mainly of magmatic water.The uranium was probably fractionated from the F-B-rich melt into the magmatic fluids, and uraniferous veins were formed as the pressure and/or temperature dropped.We suggest that the granite uranium fertility indicator, high-precision dating of uranium deposits, and the genetic link between mantle-derived material and uranium mineralization are important research topics in future. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Development Characteristics and Evolution Model of FⅠ19 Fault in Fuman Oilfield, Tarim Basin ZHANG Yintao, CHEN Shi, LIU Qiang, FENG Guang, XIE Zhou, LIANG Xinxin, LI Ting, SONG Xingguo, KANG Pengfei, PENG Zijun Geoscience    2023, 37 (02): 283-295.   DOI: 10.19657/j.geoscience.1000-8527.2022.058 Abstract （282）   HTML （14）    PDF（pc） （5533KB）（177）       Knowledge map    Save At present, the Fuman oilfield is a hot area for oil and gas development of fault-controlled fracture-cave reservoirs in the Tarim basin. FⅠ19 fault zone belongs to a current key reservoir-increasing area, but the development characteristics and formation mechanism of the faults are unclear. By using various seismic attributes, such as coherence, maximum likelihood and reservoir amplitude change rate, the newly acquired and processed three-dimensional seismic data are accurately interpreted, the development characteristics of fault profile are determined, and the spatial fault structural distribution is characterized. Based on the vertical stratigraphic displacement and the fault zone width, the fault activity intensity is inferred. Combined with the characteristics of fault deformation and the activity patterns of the peripheral orogenic belts, the fault evolution stages are analyzed and the fault development model is established. Superimposing the reservoir development characteristics and the fault distribution patterns, the fault controlling effect on the reservoir is preliminarily analyzed. The study shows that the fault has remarkable plane segmentation characteristics, which can be roughly divided into three segments (north, middle, and south) according to strike variation, and into the lower structural layer (below T∈3), the middle structural layer (T∈3-TO3t) and the upper structural layer (above TO3t) according to the fault deformation characteristics. The fault formation and evolution are multistage, and the FⅠ19 fault evolution comprises roughly of three stages: Early Caledonian (late Middle Cambrian), Middle Caledonian (Ordovician) and Late Caledonian (Silurian), among which the Middle Caledonian stage is the most active stage. The reservoir plane is mainly distributed in the strike-slip fault zone, with major differences in the reservoir development strength along the FⅠ19 fault strike. It weakens gradually from south to north, which is related to the faulting intensity. Affected by the multistage Middle Caledonian faulting, the Ordovician carbonate reservoir distribution is featured by vertical multi-layer distribution. Under the joint influence of Tabei and Tazhong fault systems, the local maximum principal stress in the Early Caledonian may have deflected counterclockwise from south to north, and gradually transferred from NNE to near NS. Two groups of X-type small-angle intersecting faults were developed, which established the local distribution pattern of FⅠ19 fault. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geoscience    2022, 36 (05): 1192-1192.   Abstract （103）      PDF（pc） （1861KB）（174）       Knowledge map    Save Related Articles | Metrics | Comments（0）

Select

Sedimentary Environment of the Phosphorus-bearing Layers and Its Phosphate Enrichment Mechanism of the Cambrian Xinji Formation, Western Henan JIA Bingling, ZHANG Biyun, TANG Bin, ZHENG Deshun Geoscience    2023, 37 (04): 858-869.   DOI: 10.19657/j.geoscience.1000-8527.2022.094 Abstract （123）   HTML （16）    PDF（pc） （10935KB）（174）       Knowledge map    Save The Cambrian is an important period for global phosphate deposition, and the Cambrian Xinji Formation is an important phosphorus-bearing sequence on the southern margin of North China Craton. However, the relationship between the phosphorus-bearing stratigraphy and the sedimentary environment is poorly understood, and the phosphate enrichment mechanism needs to be further studied. Here, we studied the middle Xinji Formation at Baofeng, which contains a typical phosphorus-bearing layer. Field observations and laboratory analyses were conducted to reveal its depositional environment and explore its phosphorus source and enrichment mechanism. The results show that phosphorus nodules from the Xinji Formation are black, irregular flat disk-shaped, with size of 2 to 20 mm, and are distributed in the fine sandstone beds. Collophanite is the main mineral in the nodules. There are two forms: (1) cryptocrystalline rounded colloidal phosphorite with no internal structure and locally cracked; (2) microcrystalline oolitic colloidal phosphorite with fine veins. The depositional environment of the Xinji Formation was likely littoral-shallow marine transition. Phosphorus was likely derived from deep oceanic phosphorus-rich water and small shell biological activities. Formation of the phosphorus nodules was likely dominated by chemical deposition with indirect biological involvement. It has undergone syn-deposition and early diagenesis stages, and large amounts of phosphorus nodules were deposited in turbulent shallow water. Compared with the Cambrian phosphorus-bearing facies in the Yangtze Craton, the phosphate-bearing stratigraphy is clearly diachronic, and phosphate deposition occurred after the sedimentary hiatus. Initial deposition of the Cambrian phosphate was dominated by biological and chemical processes, and then the depositional environment and paleotectonics controlled the phosphorus-bearing stratigraphy and promoted the re-enrichment. We point out the relationship between phosphorus enrichment and the Early Cambrian sedimentary environment in the southern North China Craton, and provide abundant data for studying large-scale phosphate deposition. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geoscience    2022, 36 (04): 978-978.   Abstract （122）      PDF（pc） （1851KB）（171）       Knowledge map    Save Related Articles | Metrics | Comments（0）

Select

Value and Excavation of Geological Culture: Taking Ahetan Geological Culture Village in Hualong County, Qinghai Province as An Example WANG Yifan, ZHANG Xujiao, ZHANG Xiangge, LI Junlei, YUAN Xiaoning, WANG Kaiya, LIU Xinlan, WANG Chongge, RAO Haoshu, LIU Jiang, QIN Yuan Geoscience    2023, 37 (05): 1423-1434.   DOI: 10.19657/j.geoscience.1000-8527.2023.114 Abstract （98）   HTML （7）    PDF（pc） （16575KB）（169）       Knowledge map    Save The construction of geological culture villages is in full swing across the country. However, its theoretical basis is not very clear, and especially most villages’ geological culture has not been fully excavated and demonstrated. Therefore, the excavation of geological culture becomes an urgent problem to be solved in the construction of geological culture villages. In 2022, Ahetan Geological Culture Village was awarded the first three-star geological culture villages in Yellow River Basin and Qinghai Province. It has made beneficial attempts and obtained good effects on geological culture excavation and three-dimensional expansion of rural culture revitalization. Based on the investigation and evaluation of heritages in Ahetan, including Yellow River terraces, ancient springs, ancient city, hollow elm tree, etc., and the in-depth excavation of geological culture, this paper systematically summarizes the definition, value, and excavation method of geological culture, and proposes it should be the theoretical basis of the construction of geological culture villages. Geological culture is all the material and spiritual wealth formed by human beings in the process of understanding, adapting, utilizing, and reforming the earth. The excavation of geological culture should focus on the close connection between geological processes and human civilization, reconstructing the history of geological processes and the harmonious relationship between humans and the planet, and demonstrating it to the public by commentary system. Through systematic summarization of geological culture and its excavation method, this paper aims to provide references for the construction and development of geological culture villages across the country. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Effect of Methane from Natural Gas Hydrate Decomposition on Marine Life GUO Zihao, LI Canping, CHEN Fengying, GOU Limin, WANG Hongtao, ZENG Xianjun, LIU Yilin, TIAN Xinyu Geoscience    2023, 37 (01): 138-152.   DOI: 10.19657/j.geoscience.1000-8527.2022.034 Abstract （311）   HTML （23）    PDF（pc） （8487KB）（168）       Knowledge map    Save With changing seabed environment and the intensification of global warming, more natural gas hydrates have decomposed and released large amount of methane into the oceans. Some of the methane would ascend through the seawater and enter the atmosphere, which would increase the atmospheric greenhouse gas concentration, and thereby exacerbate global warming. From the perspective of methane release and migration pathways, the direct/indirect effects of methane on marine life are elucidated and summarized: (1) hydrates decompose to release methane, which is an indispensable compound in lifeform formation. This provides energy and material for autotrophic microorganisms, and supplies the food base of cold-spring biota. This maintains cold-spring biota based on a food chain of chemoautotrophic bacteria, which multiply in the cold-spring ecosystem; (2) some of the methane gas would diffuse and dissolve in the seawater, which causes seawater acidification. Seawater acidification would both affect the biosynthesis of calcium carbonate shells (calcification) and accelerate the shell dissolution; (3) as a strong greenhouse gas, the released methane in the atmosphere would exacerbate global warming. In addition, the melting of the polar permafrost would also release large amount of methane into the atmosphere, which generates an adverse cycle. The warming of seawater would affect the survival, metabolism, reproduction, development and immune response of marine life and other biological activities. Our findings provide important reference for future research on the impact of methane on marine ecosystem. Table and Figures | Reference | Related Articles | Metrics | Comments（0）