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New chronological evidence for Yanshanian diagenetic mineralization in China's Altay orogenic belt

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Chinese Science Bulletin 2000年第2期45卷 108-114页

作者： Fuwen Chen Huaqin Li Denghong Wang Hong Cai Wen Chen Department of geology Peking University Beijing China Yichang institute of geology and mineral resources Ministry of Land and Mineral Resources Yichang China institute of mineral Deposits Ministry of Land and Mineral Resources Beijing China institute of geology Ministry of Land and Mineral Resources Beijing China

Granitoids and related pegmatitic rare-metal deposits are widespread in China’s Altay region,they used to be considered as Hercynian rocks and mineral *** here are the^40Ar^39Ar ages of potassium-rich minerals (muscovite and microcline)in the Koktokay pegmatitic rare-metal orefield and whole-rock as well as quartz fluid-inclusion Rb-Sr isochron ages of granite and ores in the Shangkelan pegmatite rare-metal orefield. The ages indicate that there are Yanshanian Diagenetic mineralization events happening in China’s Altay orogenic belt and that formation of the famous Koktokay No.3 pegmatitic rare-metal deposit endured about 30 Ma of magmatic crystallization differentiation.

关键词： Yanshanian diagenetic mineralization isochronological evidence Altay orogenic belt.

Ar^(39)/Ar^(40) dating of three typical gold deposits in southern Qinling and its implication

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中国有色金属学会会刊：英文版 2002年第3期12卷 498-503页

作者：汪东波邵世才冯建忠王学明 institute of geology Chinese Academy of Geological Sciences Beijing 100027 China Beijing Institute of Geology for Mineral ResourcesBeijing 100012 China beijing institute of geology for mineral resources Beijing 100012 China

Three types of gold deposits,which are the disseminated ore,auriferous quartz vein,and ore hosted in ductile shear zone have been identified in southern Qinling. The dating of the Baguamiao gold deposit in Fengxian, Xiaogouli gold deposit in Chengxian and Shangjiagou gold deposit in Kangxian gave rise to plateau ages (131.91±0.89)Ma, (197.45±1.13)Ma and (161.59±0.56)Ma respectively, consistent with the isochron ages. It is indicated that the metallization occurred in late Indosinian and early Yanshannian. The Ar 39 /Ar 40 dating affirms their metallogenic ages ranging from (131.91±0.89)Ma to (197.45±1.13)Ma which couple with the epoch in which the continent continent collision and intracontinent orogene took place. Consequently, it is suggested that the collision orogene, magmatic intrusion and location of gold deposits constitute an organic successive process. In line with the tectonic event, the large scale metallization symbolizes the different representation of the same continental dynamics in the evolution of regional tectonics.

关键词：金矿床等时线年龄地球化学南秦岭地区氩同位素

Discovery and Significance of Malan Loess on the Piedmont Plain in Pinggu District, beijing

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Acta Geologica Sinica(English Edition) 2014年第5期88卷 1565-1578页

作者： LU Lu ZHAO Yuanyi WANG Xiaoliang ZHAO Xitao YANG Zhenjing WANG Chengmin BI Zhiwei LU Wenhui institute of mineral resources Chinese Academy of Geological Sciences beijing institute of geology Liaoning institute of geology and mineral resources institute of geology and Geophysics Chinese Academy of Sciences institute of Hydrogeology and Environmental geology Chinese Academy of Geological Sciences No.3 geology and mineral Exploration institute of Gansu Provincial Bureau of geology and mineral

The platforms on both sides of the Malangou River （a lateral ditch of the Qingshui River that is a tributary of the Yongding River） where Malan Village in Zhaitang Town of Mentougou District of beijing is located are the place of China＇s typical section of the Quaternary Malan loess. During the investigation in the eastern suburbs of beijing City, the authors not only clarified 5 grades of terraces on the Pinggu piedmont plain, but also found a clayey silt section mixed with a small amount of alluvial-diluvial gravel layers at a height of 15-25 m above the river level near a Fishpond in Xinli Village of Nandule Town. Results of the study of grain size of the section document that the loess mostly is silty soil （0.05--0.005 mm）, and that the grain size probability cumulative curves of the section are dominated by single-peak, coarse-grained segment I and coarse-grained segment II types, reflecting that its depositional environment is similar to eolian phase. Identification results of heavy minerals from the section show that their contents account for 0.01%-0.11%, averaging 0.04%. There are 24 kinds of heavy minerals, most of which are stable heavy minerals, and the clay minerals mostly are illite, which is consistent with the Malan loess on the Loess Plateau. The chemical composition data reflect that the source area of the loess is relatively arid. The six grade classification of sporopollen in the section further shows the subdivision of the history of alternating warm and humid phases in this geological period. The thermoluminescence dating results range from 21.0 ka to 59.2 ka, convincingly demonstrating that the section indeed consists of Malan loess. The above studies provide a new basis for overall understanding of the distribution of the Malan loess at the northeast margin of the North China Plain and its environment change in the Late Pleistocene.

关键词： eolian loess Malan loess formation environment Pinggu

Zircon U-Pb Age, Geochemistry and Geological Implication of the 255 Ma Alkali-Rich Dykes from Ulungur Area, North Xinjiang

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Journal of Earth Science 2013年第4期24卷 519-528页

作者：陈言飞王玉往王京彬丁汝福袁月蕾石煜 School of Gemmology China University of Geosciences beijing institute ofgeology for mineral resources beijing institute of geology for mineral resources School of Earth Sciences and mineral resources China University of Geosciences

Alkali-rich dykes of the Late Permian in Ulungur （乌伦古） area are representative prod- ucts of granitic magmatism in the evolution of the Paleozoic orogenic belt in the East Junggar （准噶尔）, North Xinjiang （新疆）. We selected two representative samples for geochemical analysis （major and trace elements）, and twenty-two zircon grains for zircon dating. Isoplot （ver3.0） was used to calculate isotopic age and make concordia diagrams. This study shows that the trachy porphyry dykes, featuring low concentration of A1203, CaO, MgO and high alkali contents, are metaluminous alkaline rock and belong to A-type granitoids. The dykes have low concentration of the REE and incompatible elements, and the REE patterns show clear negative Eu anomalies （6Eu=0.74-0.58）, enriched LREE （LREE/HREE〉4, （La/Yb）N=5.97-4.63） and undifferentiated HREEs. Similar normalized REE and in- compatible element patterns are also showed in the dykes from Yemaquan （野马泉） and granites from Ulungur, suggesting that they are possibly originated from the same source and formed in the same tectonic environment, but the trachy porphyry dykes are more evolved. The age of the trachy porphyry dykes is 255.3 - 2.4 Ma, which is probably the crystallization time of the trachy porphyry. The dykes formed in late-orogenic phase of post-collision process or within-plate environment, which suggested that the trachy porphyry dykes possibly crystallized in the transition period during which the tectonic setting changed from post-collision to with- in-plate environment. So we consider that the age when the post-collision ended and the crustal cratonization begun in the East Junggar is 255 Ma, Late Permian.

关键词： Ulungur alkali-rich dyke zircon U-Pb age petrology and geochemistry tectonic setting post-collision.

Ore-forming fluid and mineralization of Caijiaying and Dajing polymetallic ore deposits

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Science China Earth Sciences 2004年第2期47卷 97-107页

作者： WANG Lijuan,WANG Jingbin, WANG Yuwang & ZHU Heping1. Key Laboratory of mineral resources, institute of geology and Geophysics, Chinese Academy of Sciences, beijing 100029, China 2. beijing institute of geology for mineral resources, beijing 100012, China Correspondence should be addressed to Wang Lijuan (email: wlj@***) 1. Key Laboratory of mineral resources Institute of Geology and Geophysics Chinese Academy of Sciences 100029 Beijing China 2. beijing institute of geology for mineral resources 100012 Beijing China

Fluid inclusions from the Dajing and Caijiaying deposits have nearly the same homogenization temperature. Correlation between temperature and salinity shows that both Sn- and Cu-bearing fluids Sn and Cu were present in the Dajing deposit but only one kind of fluids continuously evolved in the Caijiaying deposit. Study on rare earth elements (REE) in ancient fluid from the inclusions indicates that the fluid of Sn mineralizing stage in Dajing was derived from remelting magma of the continental crust, and the fluid of Cu-Pb-Zn mineralizing stage in the Dajing deposit and the fluid of Cu-Pb-Zn mineralization in the Caijiaying deposit were derived from the mantle. It is concluded that the Cu-Pb-Zn mineralizations in the Dajing and Caijiaying deposits resulted from the identical tectono-thermal event of magma-fluids induced by Mesozoic tectonic transition and extension in the eastern part of North China Craton.

关键词： Caijiaying, Dajing, Mesozoic tectonic transition, ore-forming fluid, REE.

Crustal Motion Characteristics in the Eastern Margin of the Tibetan Plateau and Adjacent Regions after the Wenchuan Earthquake

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Acta Geologica Sinica(English Edition) 2015年第5期89卷 1690-1701页

作者： TANG Wenqing ZHANG Qingzhi PAN Zhongxi LI Jun YANG Cheng Chengdu institute of geology and mineral resources

The Wenchuan earthquake has altered the crustal motion characteristics in the eastern margin of the Tibetan Plateau and adjacent *** discontinuous GPS survey data for 2008–2012, the velocity field for the Eurasia reference framework has been obtained, and the general trend of contemporary crustal motion after the occurrence of the Wenchuan earthquake has been *** addition, using the velocity field, the block movement velocity has been estimated by least-squares ***, the properties and displacement rates of main faults have been obtained from the differences in velocity vectors of the blocks on both sides of the *** results reveal that there are no obvious changes in the general characteristics of crustal motion in this area after the Wenchuan *** earthquake mainly changed the rate of the movement of the Chuan-Qing block and caused variation in the movement direction of the South China *** effect of the earthquake on faults is mainly reflected in variations in fault displacement velocity; there is no fundamental change in the properties of fault *** displacement rates of the Xianshuihe fault decreased by 3–4 mm/a, the Longmenshan fault increased by 9–10 mm/a, and the northern segment of the Anninghe fault increased by approximately 9 mm/***, the displacement rates of the Minjiang, Xueshan, Huya, Longquanshan, and Xinjin faults increased by 2–3 mm/*** implies that the effects of the Wenchuan earthquake on crustal movement can mainly be observed in the Chuan-Qing, South China, and N-Chuan-Dian blocks and their internal faults, as well as the Xianshuihe and Longmenshan faults and the northern section of the Anninghe *** reason for this is that the Wenchuan earthquake disturbed the kinematic and dynamic balance in the region.

关键词： eastern margin of the Tibetan Plateau and adjacent regions GPS measurements crustal motion characteristics Wenchuan earthquake block movement fault activity

Qinling Orogenic Belt:Its Palaeozoic-Mesozoic Evolution and Metallogenesis

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Acta Geologica Sinica(English Edition) 2000年第3期74卷 452-457页

作者： SHAO Shicai beijing institute of geology for mineral resources BeiyuanAndingmenwaiBeijing 100012

The formation, development and evolution of the Qinling orogenic belt can be divided into three stages: (1) formation and development of Precambrian basement in the Late Archaean-Palaeoproterozoic (3.0–1.6 Ga), (2) p... 详细信息

关键词： Qinling orogenic belt evolution metallogenesis

Reconstruction of the Triassic Tectonic Lithofacies Paleogeography in Qiangtang Region, Northern Qinghai-Tibet Plateau, China

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Acta Geologica Sinica(English Edition) 2013年第2期87卷 378-394页

作者： ZHU Tongxing FENG Xintao WANG Xiaofei ZHOU Mingkui Chengdu institute of geology and mineral resources

The Triassic petrostratigraphic system and chronologic stratigraphic sketch have been updated and perfected in the Qiangtang area, Qinghai-Tibet Plateau based on the integrated 1：250000 regional geological survey and the latest research progeny. The first finished 1：3000000 Triassic tectonic lithofacies paleogeographic maps in the Qiangtang area shows that the Triassic tectonic unit in the Qiangtang area can been divided into three parts from north to south： northern Qiangtang block; Longmucuo-Shuanghu suture zone; and southern Qiangtang block. The early-middle Triassic tectonic paleogeography in the Qiangtang area is divides into three sub- units： northern Qiangtang passive continental marginal basin （NQPB）, Longmucuo- Shuanghu residual basin （LSRB） and southern Qiangtang residual basin （SQRB）. The NQPB can be subdivided into four paleogeography units： The Tanggula-Zangxiahe shallow and bathyal sea; The Wangquanhe- Yingshuiquan carbonate platform; The Rejuechaka-Jiangaidarina littoral- shallow sea; and Qiangtang central uplift. The above units of The NQPB possess EW trend, geomorphology high in the south and low in the north, the seawater depth northward. The basinal paleo-current direction is unidirectional, and basinal tectonic subsidence center is in accord with the depo-center, located in the Tanggula-Zangxiahe belt, north of the basin. The sedimentation and tectonic evolution of the NQPB are characterized with passive continental marginal basin. The Qiangtang central orogenic denuded area （ancient land） may be as a sedimentary materials source of the NQPB. SQRB can be divided into two units： Duoma carbonate platform and southern Qiangtang neritic-deep sea. The late Triassic tectonic paleogeography in the Qiangtang area is the framework of the ＂archipelagic-sea＂ as a whole, and it may be divided into three sub-units： northern Qiangtang back- arc foreland basin（NQFB）, Longmucuo-Shuanghu residual basin（LSRB） and southern Qiangtang marginal-sea basin（SQMB）. Ther

关键词： Triassic sedimentary facies tectonic paleogeography Qiangtang region Qinghai-Tibet

Rare Earth Element Behaviour in theWunugetushan Copper - Molybdenum Deposit,Inner Mongolia, and Its Implications

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Acta Geologica Sinica(English Edition) 1994年第2期68卷 153-167页

作者： Qin Kezhang and Wang Zhitianbeijing institute of geology for M ineral resources, CNNC, beijing beijing institute of geology for mineral resources CNNC Beijing

Considering porphyry and wall rocks as a whole system, the behaviour of rare earth elements (REE) in hydrothermal alteration and mineralization of the exceedingly large Wunugetushan porphyry Cu-Mo deposit of Inner Mongolia has been studied. It has been found for the first time that there exists complementary REE variation in hydrothermal alteration between porphyry and wall rocks, and Eu depletion has certain significance in indicating mineralization. Based on an analysis of the variation in REE contents of relevant minerals during the hydrothermal alteration, the ore-forming fluids are inferred to be depleted in ∑REE, comparatively enriched in ∑Y and strongly depleted in Eu. In the intermediate-strong alteration zones, porphyry and wall rock took part in hydrothermal metasomatism and alteration almost in equal ratio mass. Furthermore, studies of REE and hydrogen and oxygen isotopes and fluid inclusions confirm the existence of hydrothermal convection and the possibility of supplying part of ore materials by the wall rock and indicate that the application of REE geochemistry in mineral prospecting is promising.

关键词： REE complementary nature Eu depletion hydrothermal convection Wunugetushan Cu-Mo deposit Inner Mongolia