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Rollback,scissor-like closure of the Mongol-Okhotsk Ocean and formation of an orocline:magmatic migration based on a large archive of age data

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National science Review 2022年第5期9卷 167-178页

作者： Tao Wang Ying Tong Wenjiao Xiao Lei Guo Brian F.Windley Tatiana Donskaya shan Li Narantsetseg Tserendash Jianjun Zhang Beijing sHRIMP Center Institute of Geology Chinese Academy of Geological Sciences Key Laboratory of earth Probe and Geodynamics Chinese Academy of Geological Sciences Xinjiang Research Center for Mineral Resources Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences school of Geography Geology and the EnvironmentUniversity of Leicester institute of the earth's crust Siberian Branch Russian Academy of Sciences institute of Geology Mongolian Academy of Sciences

Tracing the closure of oceans with irregular margins and the formation of an orocline are crucial for understanding plate reconstruction and continental *** eastern Central Asian Orogenic Belt,where the Mongol-Okhotsk orocline is situated,is one of the world’s largest magmatic *** a large data set of U-Pb zircon ages,we updated the timing of many published igneous rocks,which allowed us to recognize tightly ’folded’ linear Carboniferous-Jurassic magmatic belts that wrap around the Mongol-Okhotsk suture and their migrations both sutureward and *** new successive magmatic belts reveal a rollback,scissor-like(or zipper-like) closure of the Mongol-Okhotsk Ocean that was fundamentally controlled by coeval subduction rollback and rotation of the siberian and Mongolian-Erguna *** study also demonstrates the complex mechanisms and processes of the closure of an ocean with irregular margins and the formation of a consequent orocline.

关键词： magmatic migration ocean closure orocline Mongol-Okhotsk Ocean

Permian tectonic evolution and continental accretion in the eastern Central Asian Orogenic Belt:A perspective from the intrusive rocks

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Geoscience Frontiers 2024年第2期15卷 433-451页

作者： Anzong Fu Hongyan Geng Changzhou Deng Chenglu Li Jishuang Ding Bizheng Yang Wenpeng Yang Heilongjiang institute of Natural Resources survey Harbin 150036China state Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550002China science Unit Lingnan UniversityHong KongChina College of earth sciences Jilin UniversityChangchun 130061China

The tectonic evolution and history of continental accretion of the eastern Central Asian Orogenic Belt(CAOB)are not yet fully *** this study,we investigate Permian intrusive rocks from the Jiamusi Block of the eastern CAOB to constrain the tectonic evolution and continental accretion of this region during the late-stage evolution of the Paleo-Asian *** new data show that Early Permian gabbro-diorites were derived from the partial melting of depleted mantle metasomatized by oceanic-slab-released *** Permian adakitic granites have low Na2O and MgO and high K2O contents,indicating a thickened-lower-crust *** Permian s-type granites were derived from the partial melting of continental crust.A compilation of the available geochronological data for Permian intrusive rocks(including adakitic and A-,s-,and I-type granites and mafic rocks)from the eastern CAOB reveals that the A-type granites formed mainly during the Early–Middle Permian,s-type and adakitic granites mostly during the Middle–Late Permian,and I-type granites and mantle-derived mafic rocks throughout the *** A-type granites,which are proposed to have been sourced from thinned continental crust,indicate an extensional setting in the eastern CAOB during the Early *** Middle–Late Permian adakitic granites imply a thickened continental crust,which indicates a compressional ***,the eastern CAOB underwent a transition from extension to compression during the Middle Permian,which was probably triggered by the late-stage subduction of Paleo-Asian oceanic *** the petrogenesis of the intrusive rocks and inferred regional tectonic evolution of the eastern CAOB,we propose that vertical underplating of mantle-and oceanic-slabderived magmas contributed the materials for continental crust accretion.

关键词： Permian Intrusive rocks Eastern Central Asian Orogenic Belt Paleo-Asian Ocean Tectonic evolution

Imaging the western boundary of the sichuan Craton from multiple geophysical observations

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Journal of earth science 2024年

作者： Qihang Yin Xi Xu Xiaodong Yang Xuhua shi Lei Wu Andrew V.Zuza Liu Yang Hefeng Tian Yuanhai shu shufeng Yang Nevada Bureau of Mines and Geology University of Nevada China Aero Geophysical survey and Remote sensing Center for Natural Resources China Geological survey school of earth sciences Zhejiang University Research Center for structures in Oil and Gas Bearing Basins Ministry of Education Key Laboratory of Ocean and Marginal sea Geology south China sea institute of Oceanology Innovation academy of south China sea Ecology and Environmental Engineering Chinese academy of sciences school of Mechanical and Electrical Engineering Hubei Open University

The boundary between the cratonic and orogenic lithospheres is one of the most significant seismogenic zones characterized by strong lithospheric deformation. As the essential tectonic block bounding the eastern Tibetan Plateau， the sichuan Craton (sCC) resists the eastward escape of Plateau’s crustal materials， resulting in the uplift of the songpan-Ganzi Block (sGB) and the crustal deformation of the Longmenshan tectonic belt (LMTB). To uncover the compressional structures and deformational mode of the LMTB and sCC， it is crucial to determine the precise location and geometry of the western boundary of the sCC. To address this issue， the lithospheric properties of the obduction sGB， the underthrusting sCC， and the LMTB were analyzed using a series of geophysical data， including seismic reflection profiles， magnetotellurics， aeromagnetics， gravity， and seismic tomography. The crust of the sGB is characterized by low magnetism， low seismic velocity， low resistivity and low Bouguer gravity， while that of the sCC features non-uniform high magnetism， high seismic velocity， high resistivity and high Bouguer gravity. The LMTB， as the boundary between the sGB and sCC， shows the geophysical characteristics similar to the sCC along the southern and central segments. The integration of all these geophysical observations suggests that the sCC’s western boundary follows the Yingxiu-Beichuan fault along the northern segment， without obvious underthrust. However， this boundary is located west of the Wenchuan-Maoxian fault zone along the southern and central segments， with distinct westward wedging/underthrusting. The irregular geometry of the sCC’s western boundary can further explain the variation in structural deformation along the LMTB. By comparing the differences in crustal thickness and lithospheric strength between the sGB and sCC， this study suggests that the varying crustal strength between tectonic blocks may be the controlling factor for the irregular geometry of the

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segmental closure of the Mongol-Okhotsk Ocean:Insight from detrital geochronology in the East Transbaikalia Basin

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Geoscience Frontiers 2022年第1期13卷 15-27页

作者： Anastasia V.Arzhannikova Elena I.Demonterova Marc Jolivet Ekaterina A.Mikheeva Alexei V.Ivanov sergey G.Arzhannikov Valentin B.Khubanov Vadim s.Kamenetsky institute of the earth’s crust Russian Academy of SciencesSiberian BranchIrkutskRussia Laboratoire Géosciences Rennes CNRS-UMR6118Universitéde RennesRennesFrance Geological institute Russian Academy of SciencesSiberian BranchUlan-UdeRussia

The Late Paleozoic–Early Mesozoic Mongol-Okhotsk Ocean extended between the siberian and Amur–North China *** timing and modalities of the oceanic closure are widely *** is largely accepted that the ocean closed in a scissor-like manner from southwest to northeast(in modern coordinates),though the timing of this process remains *** studies have shown that both western(West Transbaikalia)and eastern(Dzhagda)parts of the ocean closed almost simultaneously at the Early–Middle Jurassic ***,little information on the key central part of the oceanic suture zone is *** performed U-Pb(LA-ICP-Ms)dating of detrital zircon from wellcharacterized stratigraphic sections of the central part of the Mongol-Okhotsk suture *** include the initial marine and final continental sequences of the East Transbaikalia Basin,deposited on the northern Argun-Idemeg terrane *** provide new stratigraphic ages for the marine and continental *** revised chronostratigraphy allows assigning an age of~165–155 Ma,to the collisionrelated flexure of the northern Argun-Idemeg terrane and the development of a peripheral foreland *** collisional process took place 5 to10 million years later than in the western and eastern parts of the *** demonstrate that the northern Argun-Idemeg terrane was the last block to collide with the siberian continent,challenging the widely supported scissor-like model of closure of the MongolOkhotsk *** segments of the ocean closed independently,depending on the initial shape of the paleo continental margins.

关键词： Detrital zircon U-Pb geochronology Mongol-Okhotsk collision East Transbaikalian Basin

Three dimensional velocity model and its tectonic implications at China seismic Experimental site,eastern margin of the Tibetan Plateau

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science China earth sciences 2024年第7期67卷 2268-2290页

作者： Jianping WU Yan CAI Wei WANG Weilai WANG Changzai WANG Lihua FANG Yaning LIU Jing LIU institute of Geophysics China Earthquake AdministrationBeijing 100081China Beijing Baijiatuan earth science National Observation and Research station Beijing 1095China Beijing earthquake Agency Beijing 100080China

The China seismic Experimental site(CsEs)is located at the intersection of the Tibetan Plateau,south China Block,and Indian Plate and has complex geological settings and intense crustal deformation,making it one of the most seismically active areas in Chinese mainland.A high-resolution,three-dimensional(3D)crust-mantle velocity structure is crucial for understanding seismotectonic environments,lithospheric deformation mechanisms,and deep dynamic *** first constructed a high-vertical-resolution 3D initial velocity model using the joint inversion of receiver functions and surface waves and then obtained a 3D P-and s-wave velocity model(CsEs-VM1.0)with the highest lateral resolution of 0.25°for the CsEs using double-difference *** to the limitations of the sn observation data,the resolution of the s-wave velocity model in the lower crust and upper mantle was reduced,making it closer to the initial model provided by joint inversion.A comparison with explosive-source seismic data showed that the synthetic P-wave first-arrival travel times of the new model were closer to the observations than those of the previous velocity *** velocity cross-sections across the source areas of the 2022 Lushan Ms6.1 and Ludian Ms6.8 earthquakes reveal that the former earthquake occurred near a weak contact zone between the Tibetan Plateau and sichuan Basin,and the rupture of the latter earthquake occurred in a granitic area,with the northern end blocked by rigid high-velocity bodies.A clear high-velocity anomaly zone is distributed along the western margin of the Yangtze Block,revealing the spatial distribution of Neoproterozoic intermediate-basic *** high-velocity zone significantly controls the morphology of fault zones and influences the rupture processes of major *** northeast-southwest and north-south trending high-velocity anomalies were found near Panzhihua,potentially related to Neoproterozoic and Middle-Late Permian intermediate

关键词： Eastern Tibetan Plateau China seismic Experimental site Yangtze Block Velocity model Double-difference tomography

Geochemistry, zircon U–Pb geochronology, and Hf isotopes of s-type granite in the Baoshan block, constraints on the age and evolution of the Proto-Tethys

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Acta Geochimica 2024年第1期43卷 40-58页

作者： Jianjun Zhang Chuanlong Mou Chendong Liu Yong Zhang Ting Chen Hualiang Li institute of Geological survey East China University of TechnologyNanchang 330013China school of earth sciences East China University of TechnologyNanchang 330013China Chengdu Geological survey Center Chengdu 610081China school of Water Resources&Environmental Engineering East China University of TechnologyNanchang 330013China

Geochemistry, zircon U–Pb geochronology, and Hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calcalkaline, strongly peraluminous rocks with A/CNK values of 1.37–1.46, are enriched in siO2, K2O, and Rb, and are depleted in Nb, P, Ti, Eu, and heavy rare earth elements,which indicates the crystallization fractionation of the granitic magma. Zircon U–Pb dating indicates that they formed in ca. 480 Ma. The Nansa granites have εHf(t) values ranging from-16.04 to 4.36 with corresponding TC DMages of 2.10–0.81 Ga, which suggests the magmas derived from the partial melting of ancient metasedimentary with minor involvement of mantle-derived components. A synthesis of data for the Early Paleozoic igneous rocks in the Baoshan block and adjacent(Tengchong,Qiangtang, sibumasu, Himalaya, etc.) blocks indicates that these blocks were all aligned along the proto-Tethyan margin of East Gondwana in the Early Paleozoic. The Early Paleozoic s-type granites from Nansa were generated in a high-temperature and low-pressure(HTLP) extensional tectonic setting, which resulted from Andean-type orogeny instead of the final assembly of Gondwana or crustal extension in a non-arc environment. In certain places, an expanding environment may exist in opposition to the tectonic backdrop of the lithosphere’s thickening and shortening, leading the crust to melt and decompress,mantle-derived materials to mix, and a small quantity of peraluminous granite to emerge.

关键词： Baoshan block Early Paleozoic Granite Geochemistry Zircon Geochronology Hf isotope

Relation between basin morphometric features and dynamic characteristics of debris flows——a case study in siberia, Russia

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Journal of Mountain science 2018年第3期15卷 618-630页

作者： Artem A.RYBCHENKO Alena V.KADETOVA Elena A.KOZIREVA institute of the earth's crust Siberian Branch of Russian Academy of Sciences

Extreme and prolonged rainfall in the Tunka Ridge caused several debris flows in the vicinity of the Arshan village(siberia, Russia) on June 28, 2014. These debris flows, in spite of similar geological conditions, had different velocity, peak discharge and alluvial fan volume values. The flow velocity was from 3.5 m/s to 19.6 m/s, the peak discharge ranged from 63 m3/s to 13566 m3/s, and the alluvial fan volume varied from 4.13×103 to 8.45×105 m3. such a great range of values is due to the morphometric parameters of the debris flow basins. The article deals with the influence of morphometric parameters of debris flow basins, such as the basin area, the average slope, Melton ratio, relief ratio on the debris flow velocity, peak discharge and volume of alluvial fans. In this debris flow event the average values of slope angle and total basin relief of the debris flow basins did not affect the values of debris flow velocity, peak discharge and alluvial fan volume. The highest correlations were observed with the debris flow basin area that was connected with the water inflow volume into the debris flow basins during the rainfall. The unequal water distribution among debris flow basins also had an impact on the debris flow velocity, peak discharge and volume of alluvial fans.

关键词：流动速度分泌物西伯利亚扇子冲积山峰体积价值

Mantle contributions to granitoids associated with sn mineralization:Geochemical and isotopic evidence from the giant Dachang deposit,south China

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Geoscience Frontiers 2024年第1期15卷 187-208页

作者： Tingyi Wang Qihai shu Xiaoping Xia Chao Li Yanning Wang Jiahao Chen Xiang sun M.santosh Qingfei Wang state Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Frontiers science Center for Deep-time Digital earth China University of Geosciences(Beijing)Beijing 100083China state Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China National Research Center for Geoanalysis Chinese Academy of Geological SciencesBeijing 100037China Department of earth science University of AdelaideAdelaideSouth Australia 5005Australia state Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China

Major sn deposits are commonly linked to crust-derived and highly evolved granites,with magma generation aided by mantle ***,whether and how the mantle components contribute to sn polymetallic mineralization remains *** this study,in combination with a compilation of equivalent data in the region,we provide new constraints on this issue based on detailed investigations on the petrogenesis and metallogenic significance of granitoids including the causative batholith and later granodiorite porphyry dike in the giant Dachang sn deposit from south *** former has zircon U-Pb ages of 93-91 Ma and belongs to highly evolved s-type biotite granite,which experienced fractionation of massive *** latter shows zircon U-Pb ages of 90 Ma and displays I-type granite *** batholith was mainly derived from the dehydration melting of biotite in the metasedimentary sources,as revealed by the relatively low whole-rock Pb contents(s(2.71-17.1)and initial T(ti-zr)of 790℃.Compared with the adjacent crust-derived s-type granites(-24.8--5.1)and I-type granites(-11.0 to-5.2),the Dachang s-type biotite granites present higher zirconεHf(t)values(-9.1 to-2.1).Furthermore,the low magmatic zirconδ18O values(6.2‰)and higher apatite LREE(3277-4114 ppm)and sr(1137-1357 ppm)contents than of arc-type basic rocks were *** characteristics jointly hint the contributions of mantle *** higher initial T(ti-zr)(>850℃),whole-rock Mg#(52 to 58),apatiteεNd(t)(-9.2 to-6.5)and zirconεHf(t)(-7.6 to 2.5)values but lower zirconδ18O values(6.33 to 8.30‰)of the later granodiorite porphyry dike than those of the batholith also suggest that mantle material was involved in the generation of the dikes,which is evident by the variational features of zircon and apatite trace *** addition,at the zircon Hf0.05,the higher zirconΔFMQ values(mostly from-1.8 to 2.0)and H2O contents(100-1100 ppm)of the Dachang

关键词： Highly evolved s-type biotite granite I-type granodiorite porphyry dike crust-mantle mixing Mantle contributions Dachang sn mineralization

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沿阿穆尔板块西边界的活动断层(蒙古领土)

地学前缘 2022年第1期29卷 245-265页

作者： Vladimir A.sANKOV Anna V.PARFEEVETs Andrey I.MIROsHNITCHENKO Aleksey V.sANKOV Amgalan BAYAsGALAN sodnomsambuu DEMBEREL institute of the earth’s crust Siberian Branch of the Russian Academy of SciencesIrkutsk 664033Russia Irkutsk state University Irkutsk 664003Russia institute of Astronomy and Geophysics of the Mongolian academy of sciences Ulaanbaatar 51Mongolia

阿穆尔板块西部边界在蒙古境内的空间位置尚不清楚,并且活动断层构造及其沿线地壳的应力状态研究较少。本文在沿此边界的三个区域——杭爱—肯特构造鞍部、布尔古特地块(鄂尔浑—土拉交汇处)和色楞格地块(包括色楞格凹陷和布伦—努鲁隆... 详细信息

阿穆尔板块西部边界在蒙古境内的空间位置尚不清楚,并且活动断层构造及其沿线地壳的应力状态研究较少。本文在沿此边界的三个区域——杭爱—肯特构造鞍部、布尔古特地块(鄂尔浑—土拉交汇处)和色楞格地块(包括色楞格凹陷和布伦—努鲁隆起),利用空间图像解译、地形起伏度分析、地质构造资料以及构造压裂和沿裂缝位移资料重建构造古应力,对活动断层进行研究。研究表明,活动断裂继承了古生代和中生代古构造的非均质性。这些断层沿着板块边界并不是单一的带,而是成簇的。它们的运动取决于走向:亚纬向断层是具有一定逆分量的左旋走滑断层,北西向断层是逆断层或逆冲断层,通常具有右旋走滑分量,海底断层是右旋走滑断层,北东向断层是正断层。位于色楞格凹陷和杭爱东部的断裂构造的活动始于上新世。逆断层和走滑断层与上新世情况不符,但多与更新世地貌相符,表明其活动年代较晚,为更新世时期。利用构造断裂和沿断裂的位移,重建活动断裂带变形末阶段的应力应变状态,结果表明断裂在最大挤压轴的北北东和北东方向上以压缩和走滑为主。只有在色楞格凹陷内,以扩张和走滑类型的应力张量为主,且在最小挤压轴的北西走向尤为显著。在南部,杭爱东部(鄂尔浑地堑)内有1个以扩张机制为主的局部区域,说明蒙古中部断裂在更新世—全新世阶段的活动以及现代地震活动主要受与印度斯坦和欧亚大陆汇聚过程相关的东北方向的附加水平挤压的控制。使研究区地壳产生走滑变形、贝加尔湖裂谷发散活动以及阿穆尔板块东南运动的另一个因素是东南方向软流圈流动对岩石圈底部的影响。阿穆尔板块和蒙古地块之间的边界在构造结构上是零碎的,代表了覆盖整个蒙古西部变形带的边缘部分。

关键词：活动断层古应力状态断层运动学碰撞的远程效应阿穆乐板块蒙古