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Confirmation of the Major Grenville Event in the Qinling Complex of the Qinling Orogenic Belt,Central China

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Journal of Earth Science 2019年第3期30卷 494-509页

作者： Chong Li Liudong Ren Shi Zong Yanbin Wang Miao Li institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China

The Qinling Complex from the Qinling orogenic belt was generally considered to be part of the Caledonian orogeny, however information of the Grenville event of the Qinling Complex has been poorly recognized. Two granite samples of greenschist-facies and two paragneiss samples of amphibolitefaices are identified from the Qinling Complex. The granites occur along the regional gneissosity of the Qinling Complex, thus it is suggested that their magmatic zircon ages(~970 Ma) mark the lower boundary of the main metamorphic age(amphibolite-granulite facies). In addition, some early-formed metamorphic zircons(~1 000 Ma) are distinguished in the granites, which may reflect the information about the source area of the granites. Therefore the major metamorphism of amphibolite-granulite facies in the Qinling Complex is constrained at Early Neoproterozoic(~1 000 Ma), not Early Paleozoic as conventionally considered. In the Early Paleozoic, the Qinling Complex was characterized by multiple extension-shear activities, overprint of greenschist-facies metamorphism and emplacement of extensive granites. These granites and related thermal events could reset the U-Pb isotopic system of the early-formed zircons, leading to the apparent zircon ages younger than their protolith age. As a result, the Qinling Complex is a modified Early Neoproterozoic orognenic belt or an independent block, which became a continental margin arc during the Early Paleozoic, being accompanied by metamorphism, deformation, and emplacement of continental arc granites. The Erlangping, Kuanping, and Taowan groups to the north of the Qinling Complex show more intensive deformation of the Caledonian, and their oblique subduction towards the Qinling Complex caused the formation of eclogites. Afterwards, the Qinling Complex was amalgamated with the Erlangping, Kuanping, and Taowan groups, which all experienced the same Caledonian orogeny, and possible later orogenies.

关键词： Neoproterozoic Caledonian metamorphism granite zircon chronology Qinling Complex

Geochronology of Yanshanian Magmatism and Metamorphism in the Hinterland of the Dabie Mountains and Their Geologic Implications

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Acta Geologica Sinica(English Edition) 1992年第2期66卷 155-163,222页

作者： Chen Tingyu Niu Baogui Liu Zhigang Fu Yunlian Ren Jishun institute of Geology, Chinese Academy of geological Sciences, beijing institute of Geology Chinese Academy of Geological Sciences Beijing

A strong tectono-magmatic thermal event has been revealed by field observations of granitic, migmatiticand metamorphic rocks in the hinterland of the Dabie Mountains. K-Ar, Ar-Ar and Rb-Sr determinationsshow that the event took place 133-117 Ma ago (Yanshanian). Contemporaneously, a southwestwardthrust-type ductile shearing at multiple levels occurred in the lower crust or at even deeper levels, suggestingthat the Dabie Mountains region was still under the influence ot strong continent-continent overlappingtectonism of the Yangtze block under the Sino-Korean block at depth. Metamorphic rocks of amphibolitefacies, migmatites and deep structural deformations resulting from this tectonothermal event are now exposedto the surface. The present features of the Dabie Mountains thus have appeared only since ca. 100 Ma B.P. Theblock composed of the Dabie Group is not an uplift or shield which would have undergone a long-continuederosion.

关键词： Geochronology of Yanshanian Magmatism and Metamorphism in the Hinterland of the Dabie Mountains and Their Geologic Implications

Geochemical Characteristics of Granitoids in the Eastern Sector of the Northern Tianshan Mountains in Xinjiang

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Acta Geologica Sinica(English Edition) 1990年第1期64卷 55-67页

作者： Wang Bixiang Li Zhaonai Zhao Guangzan Wang Fubao Zhang Shuizhe Fei Wenheng institute of Geology, Chinese Academy of geological Sciences, beijing institute of Geology Chinese Academy of Geological Sciences Beijing

The granitioids in question are located in the geosynclinal fold belt of the Northern Tianshan Mountains.The magmas are intruded into a Carboniferous marine volcanic-sedimentary rock series. forming a contempo-raneous. intermediate-basic to acid. composite intrusion. With a whole-rock Rb-Sr isochron age of 315.7 Ma. itis considered to be of middle Heicynian age. The granitoids have a SiO_2 content of 48-78%, a calc-alkali indexof 60 and silica-alkali indices ρ=2.2-2.4 and σ=1.5-2. From basic to acid compositions, the total REE con-tent increases from 38 to 143 ppm. δEu ranges from 0.47 to 0.86 and the Eu anomalies are negative. Thenormalized curves of REE of various rock types are very similar. These coupled with the characteristics of traceelement geochemistry show that the intrusion is an island arc-continental margin, calc-alkaline one. Theδ^(18)O values range from 5.8 to 8.9‰ and the ^(87)Sr/^(86)Sr initial ratio is 0.705. The materials of the intrusion arecomposed of a mixture of the magmas at the top of the upper mantle and in the lower crust, This indicates thatthe rocks might be consanguineous. differentiated and evolved products and possess the characteristics of Ⅰtype granites.

关键词： Geochemical Characteristics of Granitoids in the Eastern Sector of the Northern Tianshan Mountains in Xinjiang

Origin, Evolution and Mechanism of the Jehol Fauna

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Acta Geologica Sinica(English Edition) 1991年第2期65卷 203-215页

作者： Wang Si’en institute of Geology, Chinese Academy of geological Sciences, beijing Liu Linqun institute of Geology Chinese Academy of Geological Sciences Beijing

This paper deals with the geographic distribution and geological setting of the Jehol (northeastHebei-southwest Liaoning-southeast Inner Mongolia) fauna, and discusses the origination and the evolution ofits major biological groups. It is demonstrated that the Yan-Liao (northern Hebei-western Liaoning) area is theprovenance for the fauna. Why the fauna originated and developed in the area was intimately related to suchfactors as the palaeoclimate, palaeogeography, crustal movement, volcanism and frequent reversals of magnet-ic polarity at that time, in addition to the internal factors of the organisms themselves.

关键词： Origin Evolution and Mechanism of the Jehol Fauna

A Comparative Study of Ore-bearing Dikes and a Barren Dike in the Zaozigou Gold Deposit,Western Qinling:Zircon Morphology,U-Pb Chronology and Geochemical Constraints

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Acta Geologica Sinica(English Edition) 2024年第6期98卷 1489-1500页

作者： LIU Jiawang WANG Shuzhi WANG Tao CAO Chong QIU Junting XIE Fenquan North China University of Science and Technology TangshanHebei 063210China Chinese Academy of geological Sciences Beijing 100037China beijing Research institute of uranium Geology Beijing 100029China Bohai Rim Energy Research institute Northeastern Petroleum UniversityQinhuangdaoHebei 066004China

The Zaozigou gold deposit lies south of the Xiahe-Hezuo regional fault zone in the western Qinling orogenic belt and contains many intermediate to felsic *** porphyry,quartz diorite porphyry and biotite diorite porphyry are mineral-bearing dikes,whereas granite porphyry is unrelated to gold *** compare the relationship between different dikes and mineralization,this study analyzed the cathodoluminescence(CL)of zircon crystals in all four types of dikes exposed in the Zaozigou deposit,using a zircon typological *** formation temperature of the granite porphyry(734°C)was higher than the average temperature of the other three types of dikes(704°C),whereas the former’s alkalinity index(395)was lower than the average alkalinity index of the other three dikes(425).TheΣREE amount of granite porphyry(147.18 ppm)was smaller than the averageΣREE amount of the other three dikes(246.80 ppm)and itsδEu value(0.33)was larger than the averageδEu values of the other three dikes(0.30).The U-Pb ages of zircon in the four types of dikes were relatively consistent with the crystallization ages of approximately 240 Ma,which indicates that all four types of dikes intruded in the Middle *** to the other three ore-bearing dikes,the morphology of the zircon crystals in the barren dikes evolved from S13 to S5 and then returned to *** results indicate that the barren dike underwent an increase in temperature and a decrease in alkalinity,which may be an important reason for the absence of mineralization.

关键词： dikes zircon morphology multi-stage evolution mineralization conditions Zaozigou gold deposit

Himalayan Tectonic Evolution in the East Asian Peri-Pacific Region

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Acta Geologica Sinica(English Edition) 1990年第3期64卷 233-246页

作者： Cui Shengqin Li Jinrong institute of Geomechanics, Chinese Academy of geological Scinences, beijing Fei Zhenbi institute of Geornechanics Chinese Academy of Geological Scinences Beijing

This paper summarizes the Late Palaeozoic. Indosinian and Yanshanian palaeotectonic settings in theperi-Pacific region of East Asia. On that basis, the Himalayan crustal movement in the region is divided intothe early and late tectonic stages and two principal tectonic phases. From the ocean to the continent, 5 giganticHimalayan formation-deformation belts are distinguished; they are the Northwest Pacific trench-island arcbelt. the Northwest Pacific marginal sea basin bell. the East China Sea-northern South China Seacontinental-shelf down-faulted belt. the East Asian epicontinental rift belt. and the East Asian intracontinentalrift belt. The Early and Late Himalayan tectonic evolution is dealt with. Finally the state of the Himalayan re-gional stress field and its evoution in the region are discussed. It is considered that the mechanism of their for-mation is closely related to the continent-ocean and surface-deep earth interaction.

关键词： Asia

The Mechanism of Structural Control of Ore Formation and Geochemical Characteristics in the Massive Sulfide Deposits of the Wushan Copper Ore Field,Jiangxi

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Acta Geologica Sinica(English Edition) 1990年第3期64卷 261-274页

作者： Liu Xun institute of Geomechanics, Chinese Academy of geological Sciences, beijing Zhang Zhongmin institute of Geomechanics Chinese Academy of Geological Sciences Beijing

The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The 'optimum surface' is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center.

关键词： The Mechanism of Structural Control of Ore Formation and Geochemical Characteristics in the Massive Sulfide Deposits of the Wushan Copper Ore Field Jiangxi

The Identification and geological Significance of Fault Buried in the Gasikule Salt Lake in China based on the Multi-source Remote Sensing Data

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Acta Geologica Sinica(English Edition) 2021年第3期95卷 996-1007页

作者： WANG Junhu ZHAO Yingjun WU Ding LU Donghua National Key Laboratory of Remote Sensing Information and Image Analysis Technology Beijing Research Institute of Uranium GeologyBeijing 100029China

The salinity of the salt lake is an important factor to evaluate whether it contains some mineral resources or not,the fault buried in the salt lake could control the abundance of the ***,it is of great geological importance to identify the fault buried in the salt *** the Gasikule Salt Lake in China for example,the paper established a new method to identify the fault buried in the salt lake based on the multi-source remote sensing data including Landsat TM,SPOT-5 and ASTER *** includes the acquisition and selection of the multi-source remote sensing data,data preprocessing,lake waterfront extraction,spectrum extraction of brine with different salinity,salinity index construction,salinity separation,analysis of the abnormal salinity and identification of the fault buried in salt lake,temperature inversion of brine and the fault *** a result,the study identified an important fault buried in the east of the Gasikule Salt Lake that controls the highest salinity *** the level of the salinity is positively correlated to the mineral abundance,the result provides the important reference to identify the water body rich in mineral resources in the salt lake.

关键词： multi-source remote sensing data Gasikule Salt Lake Mangya depression China

^(40)Ar/^(39)Ar dating of shear deformation of the Xianshuihe fault zone in west Sichuan and its tectonic significance

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Science China Earth Sciences 2004年第9期47卷 794-803页

作者： ZHANG Yueqiao1, CHEN Wen2, 3 & YANG Nong1 1. institute of Geomechanics, Chinese Academy of geological Sciences, beijing 100081, China 2. institute of Geology, Chinese Academy of geological Sciences, beijing 100037, China 3. institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 100029, China institute of Geomechanics Chinese Academy of Geological Sciences Beijing China institute of Geology Chinese Academy of Geological Sciences Beijing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

Based on field geological survey, structural measurements and classical Ar/Ar dating of mica, biotite and K-feldspar, we obtain cooling ages for Miocene left-lateral shear along the Xianshuihe fault zone. The results document two thermal events during the sinistral shear. The early event (12-10 Ma) corresponds to rapid cooling of the Zheduoshan granitic massif from above 700℃ to below 350℃. The late event (5-3.5 Ma) corresponds to cooling of granites intruded along the eastern side of the fault zone. These dating results provide important thermochronological constraint on the timing of late Cenozoic eastward extrusion of the Chuan-Dian Block in the SE Tibetan margin.

关键词： Xianshuihe fault zone, Zheduoshan granitic massif, sinistral shear deformation, 40Ar/39Ar dating, late Cenozoic.