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Zircon Hf Isotope Mapping for Understanding Crustal Architecture and Its Controls on mineralization during Early Cretaceous in the Southern Great Xing'an Range,NE china

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Journal of Earth Science 2024年第1期35卷 41-50页

作者： Feng Yuan Huanan Liu Shengjin Zhao Mingjing Fan State key laboratory of geological Processes and mineral resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan 430074China State key laboratory of geological Processes and mineral resources School of Earth Sciences and ResourcesChina University of GeosciencesBeijing100083China No.10 Institute of geological Exploration Inner Mongolia Bureau of Geology and Mineral ResourcesChifeng 024000China key laboratory of Metallogeny and mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China

Voluminous Early Cretaceous granitoids and associated large-scale ore deposits are distributed within the southern Great Xing'an Range(SGXR),NE *** on previously published geochronology and zircon Hf-isotope data,Hf isotope mapping is undertaken to improve our understanding of crustal architecture and its controls on ore *** ore-related Early Cretaceous granitoids were sourced predominantly from juvenile crust,with the involvement of variable proportions of ancient crustal *** crustal architecture,as inferred from Hf isotopic contour maps,indicates two distinct Hf isotopic domains in SGXR,including(1)a higher-ε_(Hf)(+7 to+11)juvenile crust containing minor ancient crustal material,and(2)a lower-ε_(Hf)(+2 to+6)juvenile crust containing a greater proportion of ancient crustal *** Hf isotopic maps identify links between crustal architecture and regional *** deposits and other deposits with significant Cu production are restricted mainly to the higher-ε_(Hf)juvenile crustal regions in the northern and eastern *** dominated by other metals(e.g.,Mo,Sn,W,Pb,Zn,and Ag)occur mainly in the lower-ε_(Hf)juvenile crustal regions in the southern and western *** between juvenile crust-derived melts and ancient crustal components played an important role on the distribution of various ore metals.

关键词： Hf isotope mapping crustal architecture large-scale Early Cretaceous granitoids distribution of ore deposits southern Great Xing'an Range zircon

Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt,Northwest china

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Acta Geochimica 2024年第1期43卷 72-86页

作者： Jiao-Long Zhao Xiao-Jun Huang Pei-Qing Hu Zhen-Xi Yang Ying Fan Er-Teng Wang Fu-Bo Yang Jing-Yu Zhang School of Earth Sciences Key Laboratory of Mineral Resources in Western China(Gansu Province)Lanzhou UniversityLanzhou 730000China Nuclear Industry 247 Brigade Tianjin North China Geological Survey BureauTianjin 301800China Fourth Institute of geological and mineral Exploration of Gansu Provincial Bureau of Geology and mineral resources Jiuquan 735000China

Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline *** are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.

关键词： Silurian adakitic granitoids Petrogenesis Tectonic setting Qilian Orogenic Belt

Crack mechanism of ground fissures in loess layer of Fenwei Basin, china

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Journal of Mountain Science 2024年第5期21卷 1683-1696页

作者： LI Cong LU Quanzhong WANG Feiyong LUO Wenchao XU Qiang School of geological engineering and Geomatics Chang’an UniversityXi’an 710054China key laboratory of western mineral resources and geological engineering Ministry of EducationXi’an 710054China Observation and Research Station of Ground Fissure and Land Subsidence Ministry of Natural ResourcesXi’an 710054China School of engineering and Technology China University of GeosciencesBeijing 100083China

The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation routes. Nevertheless, the crack characteristics and the influence zone of ground fissures in the loess layer remain inadequately investigated. To effectively prevent and control ground fissure disasters, physical model tests and the PFC(particle flow code) numerical simulation method are used to investigate the crack mechanism of buried ground fissures in the loess layer. The results show that there are two main cracks in the layer profile, which have a Y-shape morphology. As the dip angle of the preset cracks increased from 60° to 90°, the main deformation zone at the surface gradually shifted towards the footwall. The process of crack propagation from depth to surface is divided into five stages. Additionally, the results confirm the accuracy of the width of the rupture zone d2in the footwall calculated by the cantilever beam theory. These findings can offer theoretical guidance for determining the avoidance distance of ground fissures in loess regions, as well as for implementing disaster prevention and corresponding control measures for various stages of buried ground fissure propagation.

关键词： Ground fissure Fenwei Basin Physical model test Particle flow code Crack propagation

New Discovery of the Jinshui Tin Deposit in the Middle Section of the East Kunlun Orogenic Belt,Northwestern china:mineralization Age and Exploration Significance

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Journal of Earth Science 2024年第4期35卷 1373-1377页

作者： Xingkai Zhang Shao-Yong Jiang Hui-Min Su Wei Wang Qinglin Xia Yunpeng Liu Shien Li State key laboratory of geological Processes and mineral resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan 430074China Third geological Exploration Institute of Qinghai Nonferrous geological and mineral Exploration Bureau Xining 810000China

Tin,as one of the most important critical metals,has at-tracted great attention worldwide(Jiang et al.,2023,2020).china has the largest amount of tin resources in the world,ac-counting for nearly one-fourth of the world’s total(Jiang et al.,2020;Chen and Sheng,2015).Tin deposits in china mainly occur in the Nanling Range in southern china,the Sanjiang Basin in southwestern china,and the Great Xing’an Range in northeastern china,which account for 98%of the country’s tin resources,whereas tin deposits are relatively rare in north-western china(Ni et al.,2023;Chen et al.,2014,1992).

关键词： Middle northeastern southwestern

SS-LASS Zircon Dating Deciphering Multiple Episodes of Anatexis in a Deeply-Subducted Continental Crust:An Example from Sulu Orogen,china

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Journal of Earth Science 2024年第1期35卷 85-98页

作者： Peng Feng Lu Wang Xiawen Li Wenjie Ding Zhe Chen School of Resource&Environment and Safety engineering University of South ChinaHengyang 421001China State key laboratory of geological Processes and mineral resources Center for Global TectonicsSchool of Earth SciencesChina University of GeosciencesWuhan 430074China No.8 Institute of Geology and mineral resources Exploration of Shandong Province Rizhao 276826China

‘Single shot'laser-ablation split-stream(SS-LASS)technique analyzing unpolished zircon grains makes their thin rims tenable for determination,which thus offers great potential in deciphering the timing of multiple and short-lived episodes of anatexis and metamorphism in deeplysubducted continental *** granitic gneisses in the deeply subducted continental crust undergoing considerable fluid-melt activities persist multistage growth of ***,a comparative study of SS-LASS and laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS)zircon dating was conducted on the granitic gneisses from the Sulu belt in this *** mostly show a core-mantle-rim structure with CL-bright rims thinner than 5μ*** LA-ICP-MS dating,relict magmatic zircon cores yield protolith ages of ca.756-747 Ma;whereas the dark mantles record synexhumation anatexis at ca.214 *** contrast,according to the U-Pb dates,trace element features,zircon crystallization temperatures and geological context,SS-LASS zircon petrochronology deciphers three episodes of anatectic events,as follows:(i)the first episode of anatexis at ca.218-217 Ma dominated by phengite-breakdown melting,likely facilitating the exhumation of the UHP slice from mantle depth;(ii)the second episode of anatexis at ca.193–191 Ma indicating part of northern Dabie-Sulu belt was still“hot”because of buried in the thickened orogenic crust at that time;(iii)the third episode of anatexis(ca.162–161 Ma)consistent with the intrusion ages(ca.161–141 Ma)of the Jurassic to Cretaceous granitoids in this orogen,suggesting the initial collapse of the orogenic root of the Sulu belt occurred at Late Jurassic due to the Izanagi plate initially subducting beneath the margin of Eastern *** study sheds new light upon the utilization of SS-LASS petrochronology deciphering multiple anatectic events in the deeply-subducted continental crust and supports us in better understanding the tectonic evolution of Dabie-

关键词： anatexis laser ablation laser-ablation split-stream ultrahigh-pressure metamorphic belt Sulu Orogen

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

First Record of Cyclocarya from the Early Oligocene Qaidam Basin,North Tibet:Implications for the Paleogeography and Paleoecology

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Journal of Earth Science 2024年第1期35卷 201-211页

作者： Yafei Hou Bowen Song Xiangchuan Li Fang Han Xu Zhang Kexin Zhang Institute of geological Survey China University of GeosciencesWuhan 430074China Faculty of Materials Science and Chemistry China University of GeosciencesWuhan 430074China State key laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China College of Earth Sciences and resources&key laboratory of western mineral resources and geological engineering of the Ministry of Education Chang'an UniversityXi'an 710054China State key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China School of Earth Sciences East China University of TechnologyNanchang 330013China

As the largest intermontane basin in the northeastern Tibetan Plateau(TP),the Qaidam Basin provides unique insight into paleoclimatic change and its relationship with global change and uplift on the *** this study,based on morphological comparison,fossil fruit of Cyclocarya from the Early Oligocene Shangganchaigou Formation in the Qaidam Basin is assigned as Cyclocarya *** discovery of Cyclocarya *** demonstrates the occurrence of Cyclocarya in the Oligocene sediment in Qaidam *** is the first record of Cyclocarya fossil of Early Oligocene Age in china and indicates that Cyclocarya has existed on the northeastern TP since at least the Early *** living analogues of the current fossil now lives in sub-tropical china,where the East Asian Monsoon is *** the new fossils and previously reported fossil remains of plants and fishes,it can be inferred that the Early Oligocene Qaidam Basin was primarily influenced by westerly circulation and had a relatively warm and humid climate,which was in sharp contrast to the present-day climate in Qaidam Basin.

关键词： biostratigraphy climate change winged-fruit fossil Qaidam Basin Early Oligocene paleoclimate paleogeography

Sedimentary and Heavy mineral Records for the Oligocene-Miocene Exhumation of the Easternmost Tianshan

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Journal of Earth Science 2024年第2期35卷 449-461页

作者： Yan Ding Tianyi Shen Guocan Wang Junliang Ji School of Earth Sciences Center for Global TectonicsChina University of GeosciencesWuhan430074China State key laboratory of geological Processes and mineral resources China University of GeosciencesWuhan430078China Hubei key laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan430074China

The topography of the Harlik Mountain has a strong impact on the formation of current arid climate in the Turpan-Hami ***,it is still controversial if Harlik Mountain experienced significant exhumation during the Middle to Late Cenozoic according to the previous thermochronology *** features of the Oligocene to Miocene sediments in the foreland basin could provide productive information for resolving the *** peak ages of detrital apatite fission track analysis of the Oligocene–Miocene sandstone in the Turpan-Hami Basin are well comparable with the cooling age records of the Harlik Mountain rocks,indicating that the Oligocene–Miocene Taoshuyuanzi Formation in the basin was mostly derived from the Harlik *** stratigraphic sequence exhibits coarsening upward,reflecting that the source area was in a tectonically active period during the deposition *** mineral assemblages also suggest that the unstable minerals in the sediment increased significantly at the end of the ***,the proportion of apatite increased up-section,while the garnet content decreased significantly,indicating that the Carboniferous metamorphic rocks have been gradually eroded out and more intrusive rocks have been exposed to the *** observations suggest that the Harlik Mountain experienced exhumation during the Oligocene to Miocene,and the denudation depth afterward was probably less than 2.5 km according to the previously apatite(U-Th)/He *** Oligocene–Miocene exhumation probably acted as one of the triggers for the heavy drought of the Turpan-Hami Basin during the Middle–Late Neogene.

关键词： Turpan-Hami Basin Harlik Mountain Taoshuyuanzi Formation Oligocene–Miocene uplift sedimentology structural geology

Discovery and Significance of Layered Chromite mineralization in Mafic-Ultramafic Rocks from the Gayahe Area of the East Kunlun Orogenic Belt,Northwestern china

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Journal of Earth Science 2024年第4期35卷 1367-1372页

作者： Shao-Yong Jiang Hailin Xie Wenqi Ren Bin Wang Feng Yuan Xiufeng Liu Hui-Min Su State key laboratory of geological Processes and mineral resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan 430074China Qinghai engineering Research Center of Deep Exploration Technology for Large and Ultra-Large Gold Deposits around Qaidam Basin First Geological Exploration Institute of Qinghai ProvinceHaidong 810600China

0 INTRODUCTION Chromium(Cr)is one of the most important strategic critical metals in *** primary chromite deposits can be divided into two types according to their geological setting and occurrences:podiform chromite and stratiform/layered chromite(Stowe,1994;Paktunc,1990).Podiform chromites mainly occur in ophiolites or mantle peridotites(Yang et al.,2022,2010;Bao et al.,1999).

关键词： china mantle setting