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Zircon U-Pb ages in the Nuratau ophiolitic mélange in the southern Tianshan,Uzbekistan:Implication for the closure of Paleo-Asian Ocean

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china Geology 2024年第2期7卷 365-368,I0004-I0007页

作者： Kai Weng Ji-fei Cao Divayev-Farid Karibovich Jahongir-Jurabekovich Movlanov Bo Chen Zhong-ping Ma xi’an center of geological survey China Geological SurveyXi’an 710119China The center for Geoinnovation Technologies Doctor of Sciences in Geology and Mineralogy University of Geological ScienceTashkent 100060Uzbekistan

1.Objective The Central Asian Orogenic Belt(CAOB),which is located between the European craton,Siberian craton,and Tarim-North china craton(Fig.1a),is the largest phanerozoic accretionary orogen in the world.It resulted from the longterm subduction and accretion of the Paleo-Asian Ocean(PAO).The PAO has been in existence since at least the late Mesoproterozoic(about 1020 Ma).However,there has been debate about the closing time of the PAO.

关键词： Asian Paleo Tianshan

Petrogenesis and Tectonic Implications of the Early Triassic Nianzi Adakitic Granite Unit in the Yanshan Fold and Thrust Belt:New Constraints from U-Pb Geochronology and Sr-Nd-Hf Isotopes

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 50-66页

作者： ZHANG Huijun WU Chu HE Fubing WANG Biren CUI Yubin LIU Zhenghua YOU Shina DONG Jing Development and Research center of the china geological survey Beijing 100037China Beijing Institute of the geological survey Beijing 100095China Institute of Disaster Prevention LangfangHebei 065201China

The Nianzi granite unit,which includes the Nianzi,xiaolianghou and xiawopu granitic intrusions,is a significant component of the northern part of the North china Craton(NCC)and is situated in the Yanshan fold and thrust belt(YFTB).However,there is still debate regarding the tectonic evolutionary history of the YFTB during the late Permian to Triassic period,specifically regarding the timing of subduction and collision between the NCC and the Paleo-Asian Ocean.The Nianzi granite unit exhibits unique petrological,geochronological and geochemical signatures that shed light on the tectonic evolutionary history of the YFTB.This study presents detailed petrology,whole-rock geochemistry,together with Sr-Nd isotopic,zircon U-Pb dating and Lu-Hf isotopic data of the granites within the Nianzi granite unit.Our findings demonstrate that the granites primarily consist of subhedral K-feldspar,plagioclase,quartz,minor biotite and hornblende,with accessory titanite,apatite,magnetite and zircon.Zircon U-Pb dating indicates that the xiaolianghou granite was emplaced at 247.5±0.62 Ma.Additionally,the adakitic characteristics of the Nianzi,xiawopu and xiaolianghou granitic intrusions,such as high Sr and Ba contents and high ratios of Sr/Y and(La/Yb)N,combined with negative Sr-Nd and Lu-Hf isotopes(87Sr/86Sr)i=0.705681–0.7057433,εNd(t)=−21.98 to−20.97,zirconεHf(t)=−20.26 to−9.92,as well as the I-type granite features of high SiO_(2),Na_(2)O and K_(2)O/Na_(2)O ratios,enriched Rb,K,Sr and Ba,along with depleted Th,U,Nb,Ta,P and Ti,suggest that the Nianzi granitic unit was mainly derived from the partial melting of a thickened lower crust containing hydrous,calc-alkaline to high-K calc-alkaline,mafic to intermediate metamorphic rocks.In light of these parameters,we further integrate our data with previous studies and conclude that the Nianzi granitic unit was generated in a post-collisional extensional environment during the Early Triassic.

关键词： tectonic evolution zircon geochronology Sr-Nd-Hf isotopes Nianzi granite unit Yanshan fold and thrust belt

Carbon emission reduction:Contribution of photovoltaic power and practice in china

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china Geology 2024年第2期7卷 371-376页

作者： Liang Wang Li-qiong Jia Geng xie xi-jie Chen Yang Liu Natural Resources Integrated survey Command center China Geological SurveyMinistry of Natural ResourcesBeijing 100055China Development and Research center China Geological SurveyMinistry of Natural ResourcesBeijing 100037China center for Geophysical survey China Geological SurveyLangfang 065000China

As a clean and renewable form of energy,photovoltaic(PV)power generation converts solar energy into electrical energy,reducing the consumption of fossil fuels and significantly lowering greenhouse gas emissions.Amidst the global transition towards cleaner forms of energy,countries all around the world are vigorously developing PV technology.

关键词： convert power emissions

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 unclear.In 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 pipes.The 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 reactivation.Gas 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 faults.Their 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

Genesis of the Nuri Cu-W-Mo Deposit,Tibet,china:Constraints from in situ Trace Elements and Sr Isotopic Analysis of Scheelite

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 117-131页

作者： WANG Yiyun WU Zhishan CHEN Wenqing DU Qing’an TANG Liwei SHI Hongzhao MA Guotao ZHANG Zhi LIANG Wei WU Bo MIAO Hengyi Chengdu center China Geological Survey(Geoscience Innovation Center of Southwest China)Chengdu 610081China The Second geological Institute of china’s Metallurgical Geology Bureau Fuzhou 351111China

The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,china.However,the genetic type of this deposit has been controversial since its discovery.Based on a study of the geological characteristics of the deposit,this study presents mineralization stages,focusing on the oxide stage and the quartz-sulfide stage where scheelite is mainly formed,referred to as Sch-A and Sch-B,respectively.Through LA-ICP-MS trace element and Sr isotope analyses,the origin,evolutionary process of the oreforming fluid and genesis of the ore deposit are investigated.Scanning Electron Microscope-Cathodoluminescence(SEMCL)observations reveal that Sch-A consists of three generations,with dark gray homogenous Sch-A1 being replaced by relatively lighter and homogeneous Sch-A2 and Sch-A3,with Sch-A2 displaying a gray CL image color with vague and uneven growth bands and Sch-A3 has a light gray CL image color with hardly any growth band.In contrast,Sch-B exhibits a‘core-rim’structure,with the core part(Sch-B1)being dark gray and displaying a uniform growth band,while the rim part(Sch-B2)is light gray and homogeneous.The normalized distribution pattern of rare earth elements in scheelite and Sr isotope data suggest that the early ore-forming fluid in the Nuri deposit originated from granodiorite porphyry and,later on,some country rock material was mixed in,due to strong water-rock interaction.Combining the O-H isotope data further indicates that the ore-forming fluid in the Nuri deposit originated from magmatic-hydrothermal sources,with contributions from metamorphic water caused by water-rock interaction during the mineralization process,as well as later meteoric water.The intense water-rock interaction likely played a crucial role in the precipitation of scheelite,leading to varying Eu anomalies in different generations of scheelite from the oxide stage to the quartz-sulfide stage,while also causing a gradual decrease in oxygen fugacity(fO2)and a sl

关键词： trace elements in situ Sr isotopes tungsten mineralization Gangdese metallogenic belt Tibet

geological conditions and reservoir characteristics of various shales in major shalehosted regions of china

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china Geology 2024年第1期7卷 138-149页

作者： Shu-jing Bao Tian-xu Guo Jin-tao Yin Wei-bin Liu Sheng-jian Wang Hao-han Li Zhi Zhou Shi-zhen Li xiang-lin Chen The Key Laboratory of Unconventional Petroleum Geology China Geological SurveyMinistry of Natural Resources100083 BeijingChina Oil and Gas survey China Geological Survey100083 BeijingChina Research Institute of Yanchang Petroleum(Group)CO.LTD 710076 Xi’anChina

china is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major controlling factors.This study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale gas.In general,shales in china’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas generation.Marine strata generally show high degrees of thermal evolution.In contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these shales.The shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of shales.These shales are followed by those in the Niutitang and Longtan formations.In contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low porosities.Furthermore,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral contents.Despite a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some extent.For marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production.

关键词： Shale gas Marine shale Continental shale Marine-continental transitional shale Neoproterozoic-Cretaceous strata geological conditions Reservoir characteristics Petroleum geological survey engineering

Enhancing geological Understanding and Identifying Gold Anomalies in the Ailaoshan Orogen

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 441-453页

作者： ZHAO Shiyu YANG Lin SONG Yiwei DONG Yuntao FENG Lihao LI Huajian WU Junyu WANG Qingfei State Key Laboratory of geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China xi’an center of Mineral Resources survey China Geological SurveyXi’an 710010China Yunnan Gold Mining Industry Group Kunming 650299China Jiangxi Provincial Key Laboratory of Genesis and Prospect for Strategic Minerals East China University of TechnologyNanchang 330013China Frontiers Science center for Deep-time Digital Earth China University of Geosciences(Beijing)Beijing 100083China

The Ailaoshan Orogen in the southeastern Tibet Plateau,situated between the Yangtze and Simao blocks,underwent a complex structural,magmatic,and metamorphic evolution resulting in different tectonic subzones with varying structural lineaments and elemental concentrations.These elements can conceal or reduce anomalies due to the mutual effect between different anomaly areas.Dividing the whole zone into subzones based on tectonic settings,ore cluster areas,or sample catchment basins(Scb),geochemical and structural anomalies associated with gold(Au)mineralization have been identified utilizing mean plus twice standard deviations(Mean+2STD),factor analysis(FA),concentration-area(CA)modeling of stream sediment geochemical data,and lineament density in both the Ailaoshan Orogen and the individual subzones.The FA in the divided 98 Scbs with 6 Scbs containing Au deposits can roughly ascertain unknown rock types,identify specific element associations of known rocks and discern the porphyry or skarn-type Au mineralization.Compared with methods of Mean+2STD and C-A model of data in the whole orogen,which mistake the anomalies as background or act the background as anomalies,the combined methods of FA and C-A in the separate subzones or Scbs works well in regional metallogenic potential analysis.Mapping of lineament densities with a 10-km circle diameter is not suitable to locate Au deposits because of the delineated large areas of medium-high lineament density.In contrast,the use of circle diameters of 1.3 km or 1.7 km in the ore cluster scale delineates areas with a higher concentration of lineament density,consistent with the locations of known Au deposits.By analyzing the map of faults and Au anomalies,two potential prospecting targets,Scbs 1 and 63 with a sandstone as a potential host rock for Au,have been identified in the Ailaoshan Orogen.The use of combined methods in the divided subzones proved to be more effective in improving geological understanding and identifying mineralization anomalies associated with Au,rath

关键词： minerology geochemistry gold stream sediment sample catchment basin concentration-area model lineament density Ailaoshan Orogen

A New Discovery of Mineralization as Subseafloor Hydrothermal Replacement in the Duddar Super-Large SEDEX Lead-Zinc Deposit in Pakistan

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Journal of Earth Science 2024年第3期35卷 1075-1078页

作者： Huishan Zhang Yucai Song Jianing Sun Jun Hong Yasir Shaheen Khalil Yanguang Li Haidi Zhang Zhihua Wang MNR Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits Xi’an Center of Geological SurveyChina Geological SurveyXi’an 710054China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Chengdu center of geological survey China Geological SurveyChengdu 610081China china Huaye Group Co. LtdBeijing 100037China geological survey of Pakistan Islamabad 44000Pakistan

0 INTRODUCTION Sedimentary exhalative(SEDEX)lead-zinc deposit was traditionally considered as a result of submarine hydrothermal exhalation,including exhalative plume and brine pool models(Izanloo et al.,2022;Spinks et al.,2021;Maghfouri et al.,2020;Sangster,2020,2018;Huang et al.,2019;Rajabi et al.,2015;Goodfellow and Lydon,2007;Large et al.,2005,2001;Peng et al.,2000;Goodfellow et al.,1993;Figures 1a,1b).However,recognition of mineralization as subseafloor hydrothermal replacement in a few SEDEX deposits has challenged the traditional consideration(Magnall et al.,2023,2021,2020a,b;Hayward et al.,2021;Figure 1c).Researchers come to believe that subseafloor replacement rather than submarine exhalation is a dominant process for SEDEX mineralization,but this needs to be examined through more case studies.

关键词： submarine mineralization seafloor

Significant lake expansion has accelerated permafrost degradation on the Qinghai-Tibet Plateau

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Journal of Mountain Science 2024年第1期21卷 68-83页

作者： LI Qingpeng LIU Wenhui LIU Hairui ZHOU Guanghao SONG xianteng LI Qing LUO Bingnan SONG Bangxu ZHANG Qi Department of geological Engineering Qinghai UniversityXining 810016China College of Eco-Environmental Engineering Qinghai UniversityXining 810016China xining center for Integrated Natural Resources survey China Geological SurveyXining 810000China

In recent years, lakes on the Qinghai-Tibet Plateau have become more responsive to climate change. In September 2011, Zonag Lake in Hoh xil experienced sudden drainage, the water eventually flowed into Yanhu Lake, which caused Yanhu Lake to continue to expand. The potential collapse of Yanhu Lake could directly threaten the operational safety of the adjacent Qinghai-Tibet Highway, Qinghai-Tibet Railway. To explore the implications of expanding lakes on the surrounding permafrost, we selected Hoh xil Yanhu Lake on the Qinghai-Tibet Plateau to study the effect of lake expansion on permafrost degradation. The permafrost degradation in the Yanhu Lake basin from October 2017 to December 2022 was inverted using Sentinel-1 satellite image data and small baseline subset interferometry synthetic aperture radar(SBAS-In SAR) technology. Additionally, permafrost degradation from February 2007 and February 2010 was analyzed using advanced land observing satellite phased array-type L-band synthetic aperture radar(ALOS PALSAR) satellite images and differential interferometric synthetic aperture radar(D-In SAR) technique. The results showed that the permafrost around Yanhu Lake experienced accelerated degradation. Prior to the expansion of Yanhu Lake, the average annual deformation rate along the line of sight(LOS) direction was 6.7 mm/yr. After the expansion, the rate increased to 20.9 mm/yr. The integration of spatial-temporal distribution maps of surface subsidence, Wudaoliang borehole geothermal data, meteorological data, Yanhu Lake surface area changes, and water level changes supports the assertion that the intensified permafrost degradation could be attributed to lake expansion rather than the rising air temperature. Furthermore, permafrost degradation around Yanhu Lake could impact vital infrastructure such as the adjacent Qinghai-Tibet Highway and Qinghai-Tibet Railway.

关键词： Lake expansion SBAS-InSAR D-InSAR Permafrost deformation Qinghai-Tibet Plateau