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Timing and Tectonic Setting of the Gaoaobei TungstenMolybdenum Deposit in Nanling Range, south China

Journal of Earth Science 2024年第3期35卷 890-904页

作者： Jianfeng Li Kemeng Ma Youyue Lu Jianming Fu Shunbo Cheng Yuan Li Chuanbiao Li College of Geographical Science Liaoning Normal UniversityDalian 116029China Wuhan Center of geological survey China Geological SurveyWuhan 430205China Granite Diagenesis and Mineralization Geology Research Center China Geological SurveyWuhan 430205China Mineral Resources survey Institute of Hunan Province Changsha 410083China

The Gaoaobei tungsten-molybdenum deposit is a newly discovered large-scale quartzvein-type deposit in the Nanling metallogenic belt in south *** ore bodies are hosted in the Indosinian granites and the Cambrian Xiangnan Group slates and are controlled by NWW-oriented faults,which are obviously different from the“five-story building”model in southern Jiangxi *** magmatic rocks in the study area are dominated by medium-to coarse-grained biotite monzogranite,with a few NW-oriented fine-grained granite *** medium-to coarse-grained biotite monzogranite and fine-grained granite dykes have zircon U-Pb ages of 229.4±1.9 Ma(MSWD=1.5)and 164.9±3.3 Ma(MSWD=0.75),respectively,corresponding to the Indosinian and Yanshanian *** monzogranites have higher contents of FeO,CaO,K2O,P2O5,and TiO2,while the granite dykes have slightly higher contents of SiO2,Al2O3,MnO,and *** A/CNK values are 1.11-1.75 and 1.19-2.25,and the contents of CIPW normative corundum are 1.71%-6.66%and 2.41%-9.50%,suggesting both the monzogranites and granite dykes are S-type *** total amount of rare earth elements in the monzogranites(from 84.7 ppm to 129 ppm)is slightly lower than that in the granite dykes(from 128 ppm to 133 ppm).The Eu/Eu*values range from 0.12 to 0.30 in monzogranites and from 0.0011 to 0.0013 in granite dykes,indicating the fine-grained granites underwent more intense fractional *** monzogranite and granite dykes have high 87Sr/86Sri values of 0.7169-0.7193 and 0.72825-0.72880,lowεNd(t)values ranging from-10.2 to-9.6 and from-11.5 to-11.4,and TDM2 ages of 1835-1785 and 1957-1946 Ma,*** isotope data indicate their origin from the remelting of the Paleoproterozoic crustal *** with regional geology,it is concluded that the medium-to coarse-grained biotite monzogranite was formed in a post-collisional extensional *** addition,40Ar-39Ar dating of the greisen type tungsten-molybdenum ore gave

关键词： zircon U-Pb age 40Ar-39Ar age geochemistry tungsten molybdenum deposit Gaoaobei Nanling Range.

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Deep-large faults controlling on the distribution of the venting gas hydrate system in the middle of the Qiongdongnan Basin, south China Sea

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China Geology 2024年第1期7卷 36-50页

作者： Jin-feng Ren Hai-jun Qiu Zeng-gui Kuang Ting-wei Li Yu-lin He Meng-jie Xu Xiao-xue Wang Hong-fei Lai Jin Liang National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou 511458China Guangzhou Marine geological survey China Geological SurveyGuangzhou 511458China China geological survey Ministtry of Natural ResourcesBeijing 100037China

Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migration and gas hydrates distribution in tectonically inactive regions is still *** this study,the authors apply high-resolution 3D seismic and logging while drilling(LWD)data from the middle of the QDNB to investigate the influence of deep-large faults on gas chimneys and preferred gasescape *** findings reveal the following:(1)Two significant deep-large faults,F1 and F2,developed on the edge of the Songnan Low Uplift,control the dominant migration of thermogenic hydrocarbons and determine the initial locations of gas chimneys.(2)The formation of gas chimneys is likely related to fault activation and *** chimney 1 is primarily arises from convergent fluid migration resulting from the intersection of the two faults,while the gas chimney 2 benefits from a steeper fault plane and shorter migration distance of fault F2.(3)Most gas-escape pipes are situated near the apex of the two *** reactivations facilitate free gas flow into the GHSZ and contribute to the formation of fracture‐filling hydrates.

关键词： Venting gas hydrates Deep-large faults Gas chimney Gas-escape pipes High-resolution 3D seismic Logging while drilling Qiongdongnan Basin south China Sea

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Jet Characteristics and Optimization of a Cavitation Nozzle for Hydraulic Fracturing Applications

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Fluid Dynamics & Materials Processing 2024年第1期20卷 179-192页

作者： Yu Gao Zhenqiang Xu Kaixiang Shen Shenzhen south China Sea Oil Economic Development Co. Ltd.Shenzhen518000China Guangzhou Marine geological survey China Geological SurveyGuangzhou511458China National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou511458China

Hydraulic jetting is a form of fracturing that involves using a high-pressure jet of water to create fractures in the reservoir rock with a nozzle serving as the central component of the hydraulic sandblasting perforation *** this study,the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ωturbulence *** results show that the nozzle structure can significantly influence the jet performance and related cavitation *** orthogonal experiments,the nozzle geometric parameters are optimized,and the following configuration is found accordingly:contraction angle 20°,contraction segment length 6 mm,cylindrical segment diameter 6 mm,cylindrical segment length 12 mm,spread segment length 10 mm,and spread angle 55°.

关键词： Cavitation jet angle nozzle hydraulic characteristics nozzle parameters

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Ordovician integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 971-1004页

作者： Xiang FANG Yong Yi ZHEN Guangxu WANG Xin WEI Zhongyang CHEN Yan LIANG Xuejin WU Wenjie LI Chao LI Renbin ZHAN Yuandong ZHANG State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China geological survey of New south Wales W.B.Clarke Geoscience CentreNSW 2753Australia University of Chinese Academy of Sciences Beijing 100049China

The Ordovician rocks on the Qinghai-Tibetan Plateau represent the oldest non-metamorphic strata,and are critical to understanding the history of regional geology and biotic evolution of the entire *** of Floian,Darriwilian,Sandbian,Katian and Hirnantian are represented in the plateau with a hiatus of variable duration occurring underneath the basal Ordovician across the *** stratigraphical regions,including the Himalaya,Gangdise-Zayu,Qiangtang-Qamdo,Songpan-Garze,and Karakoram-Kunlun-Altun,are differentiated for the Ordovician strata,which are correlated with their equivalents in the Sibumasu,Indochina,Qaidam-Qilian,Tarim-Tianshan,and the Yangtze(western margin)stratigraphical *** the QinghaiTibetan Plateau,graptolites,conodonts,and cephalopods are the most common and useful fossils for the Ordovician *** Ordovician biotas of the Qinghai-Tibetan Plateau bear some distinguishable palaeobiogeographical signatures,among which the cephalopods are characterized by the flourishing actinocerids of North China affinity in the Early-Middle Ordovician,and by the thriving lituitids and orthocerids of south China affinity in the Middle-Late *** occurrences and their palaeobiogeographical evolution provide critical evidence bearing on the reconstruction of the geological history of the Qinghai-Tibetan Plateau and surrounding terranes in northeastern *** stratigraphical successions of the Cambrian-Ordovician transition in the Himalaya and Lhasa and nearby Sibumasu terranes were significantly affected by the Kurgiakh Orogeny,which resulted in the extensive unconformity between the Ordovician and the underlying rocks in most areas of the Qinghai-Tibetan *** southern Xizang,a warm-water biota of Middle Ordovician age was recovered from oolitic limestones,suggesting a likely palaeogeographical location in low-latitudes near the *** the Himalaya and Sibumasu regions,the Upper Ordovician was typified by t

关键词： Ordovician Chronostratigraphy Lithostratigraphy Biostratigraphy Palaeobiogeography Qinghai-Tibetan Plateau

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Comparative study of different machine learning models in landslide susceptibility assessment: A case study of Conghua District, Guangzhou, China

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China Geology 2024年第1期7卷 104-115页

作者： Ao Zhang Xin-wen Zhao Xing-yuezi Zhao Xiao-zhan Zheng Min Zeng Xuan Huang Pan Wu Tuo Jiang Shi-chang Wang Jun He Yi-yong Li Wuhan Center China Geological SurveyMinistry of Natural Resources(Geosciences Innovation Center of Central South China)Wuhan 430205China Guangzhou Institute of geological survey Guangzhou 510080China Hubei Transportation Planning Design Institute Co. LtdWuhan 430050China

Machine learning is currently one of the research hotspots in the field of landslide *** clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Conghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility *** evaluation factors were selected by using correlation analysis and variance expansion factor *** four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were *** analysis and evaluation of the model were conducted through statistical indices and receiver operating characteristic(ROC)*** results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,*** model had the highest predictive ability,followed by RF model,SVM model,and LR *** frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,*** and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems.

关键词： Landslides susceptibility assessment Machine learning Logistic Regression Random Forest Support Vector Machines XGBoost Assessment model geological disaster investigation and prevention engineering

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Application of geophysical methods in fine detection of urban concealed karst:A case study of Wuhan City,China

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China Geology 2024年第3期7卷 517-532页

作者： Dao-han Liu Lei Wang Lei Liu Jun-jie Xu Jian-qiang Wu Pan Liu Wuhan Center China Geological SurveyWuhan430205China Central south China Center for Geoscience Innovation Wuhan430205China Geophysical Exploration Brigade of Hubei geological Bureau Wuhan 430056China

The construction of modern livable cities faces challenges in karst areas,including ground collapse and engineering ***,with a population of 13.74×10^(6) and approximately 1161 km^(2)of soluble rocks in the urban area of 8569.15 km^(2),predominantly consists of concealed karst areas where occasional ground collapse events occur,posing significant threats to underground engineering *** address these challenges,a comprehensive geological survey was conducted in Wuhan,focusing on major karstrelated *** methods offer advantages over drilling in detecting concealed karst areas due to their efficiency,non-destructiveness,and *** paper reviewed the karst geological characteristics in Wuhan and the geophysical exploration methods for karst,selected eight effective geophysical methods for field experimentation,evaluated their suitability,and proposed method combinations for different karst *** results show that different geophysical methods have varying applicability for karst detection in Wuhan,and combining multiple methods enhances detection *** specific recommendations for method combinations provided in this study serve as a valuable reference for karst detection in Wuhan.

关键词： Ground Penetrating Radar(GPR) Electric Resistivity Tomography(ERT) Opposing-coils Transient Electromagnetic Method(OCTEM) Microtremor Array Measurements(MAM) Multi-channel Analysis of surface wave(MASW) Multi-source surface wave exploration(MSSW) Electromagnetic wave CT(EM CT) Surface Nuclear Magnetic Resonance(SNMR) Concealed karst Urban geological survey engineering

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Hcable for Time-Lapse Seismic Monitoring of Marine Carbon Capture and Storage

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哈尔滨工程大学学报（英文版） 2024年第3期23卷 628-633页

作者： Bin Liu Yutong Fu Pengfei Wen Guangzhou Marine geological survey Guangzhou 511458China Sanya Institute of south China Sea Geology Guangzhou Marine Geological SurveyChina Geological SurveySanya 572025China

To ensure project safety and secure public support, an integrated and comprehensive monitoring program is needed within a carbon capture and storage(CCS) project. Monitoring can be done using many well-established techniques from various fields, and the seismic method proves to be the crucial one. This method is widely used to determine the CO_(2) distribution, image the plume development, and quantitatively estimate the concentration. Because both the CO_(2) distribution and the potential migration pathway can be spatially small scale, high resolution for seismic imaging is demanded. However, obtaining a high-resolution image of a subsurface structure in marine settings is difficult. Herein, we introduce the novel Hcable(Harrow-like cable system) technique, which may be applied to offshore CCS monitoring. This technique uses a highfrequency source(the dominant frequency>100 Hz) to generate seismic waves and a combination of a long cable and several short streamers to receive seismic waves. Ultrahigh-frequency seismic images are achieved through the processing of Hcable seismic data. Hcable is then applied in a case study to demonstrate its detailed characterization for small-scale structures. This work reveals that Hcable is a promising tool for timelapse seismic monitoring of oceanic CCS.

关键词： Carbon capture and storage Hcable Seismic monitoring High resolution image High frequency seismic source

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Structural Control of the Getang Carlin-Type Gold Deposit in southwest China

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Journal of Earth Science 2024年第2期35卷 536-552页

作者： Guoping Zeng Xinlu Hu Diwei Luo Jianzhong Liu Shuzhen Yao Yongjie Jin Wuhan Center China Geological SurveyWuhan430205China Central south China Innovation Center for Geosciences Wuhan430205China Faculty of Earth Resources China University of GeosciencesWuhan430074China geological Party 105 Guizhou Bureau of Geology and Mineral Exploration&DevelopmentGuiyang550018China

The Getang is a representative Carlin-type gold deposit in southwest *** has a proven reserve of about 30 tonnes at an average grade of 5.1 g/t *** orebodies occur as strat-abound lenses,and are structurally controlled by shallow NWW-and NE-trending fold-fault systems and the unconformity between the Upper and Middle *** this study,the regional-and deposit-scale structural investigations,joints and finite strain measurements,and stress and dynamic analysis were conducted with an aim to reveal the structural process of the Getang gold deposit and clarify the relationship between the gold mineralization and *** phases of deformation were identified in the deposit:(1)paleokarst was generated by a crustal uplift when the Youjiang Basin experienced extension at the end of the Middle Permian,laying the foundation for the unconformity;(2)the NW-trending structures were formed under a NNE-SSW compression during the Indochina-south China collision(Indosinian orogeny)in Triassic;(3)the NE-trending structures were generated or reactivated under a NW-SE-oriented compression during the Yanshanian intracontinental *** unconformity recorded two episodes of tectonic evolution in the NNE-SSW and NW-SE *** analyses and geochronology data suggest that the Getang gold deposit was formed as a result of tectonic transition from compression to extension during the Yanshanian intracontinental orogeny.

关键词： Carlin-type gold deposit structural features finite strain Getang southwest China economy geology geochemistry

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Evolution of the Mangrove Wetland since the Holocene:Current Progress and Future Perspectives

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Journal of Earth Science 2024年第5期35卷 1669-1678页

作者： Xueyan Yan Xianzhong Ke Qinghua Li Yiqun Gan Xianjun Xie Yamin Deng geological survey China University of GeosciencesWuhan 430074China Wuhan Center China Geological Survey(Central South China Innovation Center for Geosciences)Wuhan 430205China School of Environmental Studies China University of GeosciencesWuhan 430074China

Mangrove wetlands are among the four most productive tropical and subtropical *** are also a core component of the coastal blue carbon ecosystem,which is of great ecological significance to human beings,plants,animals,and the global carbon *** has been a global decrease in the distribution of mangrove forests,and their ecological function has gradually degenerated since the *** from coastal mangrove wetlands can provide records of climate change and human activities,and multiple proxies including palynology,leaf fossil,biomarkers,DNA,phytolith and stable isotopes,can be used to reconstruct the evolutionary stages of paleo-mangroves and to identify the effect of natural processes and human activities on the distribution and evolution of *** information can provide theoretical support for mangrove protection and for improving carbon sequestration *** paper summarizes and compares the multiple proxies for mangrove reconstruction,reviews progress in the study of natural succession of global mangroves since the Holocene,expands on the influence mechanisms of human activities on mangrove growth and development and uses past information to lay a foundation for a model to predict future mangrove development.

关键词： mangrove Holocene multiproxy sedimentary environment climate change environ-mental geology

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Characteristics of Paleontological Communities in Surface Sediments of the southern south China Sea and Their Paleoclimatic and Paleoenvironmental Significance

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Journal of Earth Science 2024年第1期35卷 144-154页

作者： Jing Zhao Li Zhang Xiaoyan Wang Jinglian Ge Min Xu Wei Chen Mao Luo Qianyong Liang Qiuhua Yu Shuaibing Luo Wenkun Qie Key Laboratory of Marine Mineral Resoures Ministry of Natural ResourcesGuangzhou Marine Geological SurveyChina Geological SurveyGuangzhou 511458China National Engineering Research Center for Gas Hydrate Exploration and Development Guangzhou 511458China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China

Understanding the spatial and temporal distribution of different paleontological communities in the southern south China Sea(SCS)is fundamental to explore its paleoclimatic and paleoenvironmental *** this study,foraminifera,pollen and diatoms from 100 surface sediment samples covering 40000 km^(2) of sea floor in the southern SCS were comprehensively investigated in terms of their assemblage and *** results showed the existence of abundant foraminifera and pollen in most of the samples,although diatom communities were relatively *** were dominated by ***,***,***,while diatoms were characterized by ***,*** and ***,indicating a typical tropical marine *** pollen assemblages showed a better reflection of montane rainforest,tropical rainforest and *** spatial differences among foraminifera assemblages may indicate the effect of water depth and a warmer environment in the southeast part of the study area,while the spatial patterns of diatom and pollen assemblages imply the influence of coastal *** study also noted that the compositions of paleontological communities in the SCS can vary significantly in a short distance,and synthesized studies on multiple biological groups are needed to reconstruct the Quaternary climate and the oceanographic environment.

关键词： southern south China Sea sediments foraminifera diatom pollen

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