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Acta Geologica Sinica(English Edition) 2003年第2期77卷 173-186页

作者： zhang zeming, xu zhiqin and xu huifeninstitute of geology, chinese academy of geological sciences, 26 baiwanzhuang rd., beijing 100037 E-mail: zzm@***. Institute of geology Chinese Academy of Geological Sciences 26 Baiwanzhuang Rd. Beijing 100037

The Drillhole ZK703 with a depth of 558 m is located in the Donghai area of the southern Sulu ultrahigh-pressure (UHP) metamorphic belt, eastern China, and penetrates typical UHP eclogites and various non-mafic rocks, including peridotite, gneiss, schist and quartzite. Their protoliths include ultramafic, mafic, intermediate, intermediate-acidic, acidic igneous rocks and sediments. These rocks are intimately interlayered, which are meters to millimeters thick with sharp and nontectonic contacts, suggesting in-situ metamorphism under UHP eclogite facies conditions. The following petrologic features indicate that the non-mafic rocks have experienced early-stage UHP metamorphism together with the eclogites: (1) phengite relics in gneisses and schists contain a high content of Si, up to 3.52 p.f.u. (per formula unit), while amphibolite-facies phengites have considerably low Si content (26 p.f.u.); (2) jadeite relics are found in quartzite and jadeitite; (3) various types of symplectitic coronas and pseud

关键词： UHP metamorphism non-mafic rock drillhole Dabie-Sulu orogenic belt eastern-central China

Ages and Compositions of the Precambrian High-grade Basement of the Qilian Terrane and Its Adjacent Areas

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Acta Geologica Sinica(English Edition) 2001年第4期75卷 375-384页

作者： WAN Yusheng, xu zhiqin, YANG Jingsui and zhang Jianxin Institute of geology, chinese academy of geological sciences, beijing 100037 Institute of geology Chinese Academy of Geological Sciences Beijing 100037 [?]2Wan Yusheng Born in 1958 graduated from China University of Geosciences in 1981 received the Ph.D. degree in 1993 now senior geologist at the Institute of geology Chinese Academy of Geological Sciences engaged in the study of geochemistry. Tel: 010–68328411 e-mail: wanysh@***

Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8–1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47–0.71 and Ba/Ba*=0.16–0.64), with fDM and ENd (1.0 Ga) ranging from 1.87 to 2.26 Ga and from ?8.54 to ?4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane were separated from each other, belonging to different plate systems of the North China craton and Yangtze platform respectively. The Qilian orogenic belt was the same as or similar to the Qiling orogenic belt in terms of the geological evolution history at least before the Jinningian period.

关键词： Qilian terrane chronology Nd isotope geochemistry Precambrian basement

THE ALTUN—NORTH QAIDAM ECLOGITE BELT IN WESTERN CHINA—ANOTHER HP-UHP METAMORPHIC BELT TRUNCATED BY LARGE SCALE STRIKE-SLIP FAULT IN CHINA

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地学前缘 2000年第S1期7卷 254-255页

作者： zhang Jianxin, xu zhiqin, Yang Jingsui, Li Haibing, Wu Cailai(Institute of geology, chinese academy of geological sciences, 26 baiwanzhuang, beijing 100037,China, E\|mail: zjx66@***)

The Altun and North Qaidam Mountains at the northern margin of Qinghai\|Tibet plateau are separated by the Altyn Tagh sinistral strike\|slip fault, which is one of the largest strike\|slip fault systems in the world and was considered as the key element in the escape tectonics model for Euraisa\|India continent\|continent ***,the eclogites within quratzifeldspathic gneisses or pelitic gneisses characterized by amphibolite\|facies paragenesis were discovered in the Altun and the North Qaidam Mountains(Fig.1). They occur as lens or boundins within the Altun Group and Dakendaban Group respectively which previously were considered as metamorphic basement of Tarim block and Qaidam block. Our studies indicate that the eclogites outcrop in both the Altun and North Qaidam Mountains show similar occurrences, associated country rocks, rock and mineral assemblages, p\|T\% estimates, geochemistryand protolith feature and ages of peak metamorphism (see table) . The garnet\|omphacite\|phengite geothermobarometer gave equilibrium condition of \%p\%=2 8～3 0GPa and t =820～850℃ for the Altun eclogite and p =2 8GPa and \%t\%=730℃ for North Qaidam eclogite respectively(Fig..2). These p\|T conditions are in the coesite stability field. Moreover, Po lycrystalline quartz pseudomorphs after coesite have been identified in the Dulan area, North Qaidam Mountains (Song et al, in review). Therefore, these features suggest that both eclogites of Altun and North Qaidam Mountains probably are a same HP\|UHP metamorphic belt formed from the same of Early Paleozoic age deep subduction and collision, and subsequently displaced by the Altyn Tagh *** case is similar to the Dabie\|Sulu HP\|UHP metamorphic zone which was truncated by the Tanlu sinistral strike\|slip fault and splitted it into two distincts, the Dabie region and Sulu region. These correlations support an about 350～400km displacement of the Altyn Tagh sinistral strike\|slip fault (Fig.1).

关键词： Altun mountains North Qaidam Mountains HP\|UHP metamorphic b elt Altyn Tagh fault

THREE-DIMENSIONAL DEFORMATION ALONG THE ALTYN TAGH FAULT ZONE AND UPLIFT OF THE ALTYN MOUNTAIN, NORTHERN TIBET

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地学前缘 2000年第S1期7卷 257-258页

作者： Li Haibing, Yang Jingsui, xu zhiqin, zhang Jianxin, Wu Cailai,Shi Rendeng (Institute of geology, chinese academy of geological sciences, 26 baiwanzhuang Road, beijing 100037, China,E\|mail: lihaibing@*** yangjsui@***)

he convergence between India and Eurasia is partly accommodated by motion of a few large blocks along strike\|slip faults. About 1800km long Altyn Tagh fault strikes in N60～80°E and allows the northeastward.displacement of the Tibet plateau relative to the Tarim. The Altyn Tagh fault zone is a typical transpressional fault zone, characterized by blocks rotation and crustal shortening and vertical extrusion of blocks within the Altyn Tagh strike\|slip system. Differences of three\|dimensional deformation and configuration of the active structures are recognized at different segment of the Altyn Tagh fault zone.1\ Structural configuration of the Altyn Tagh fault zone\;In the Altyn Tagh strike\|slip fault zone, the assemblage pattern of the (active) faults is in the form of parallel plumes, especially in the eastern and the western segments of the Altyn Tagh fault zone. These plumes structures in the eastern segment are assembled by string\|like left lateral strike\|slip fault and broom\|like thrusting faults, and in the western segment by arc\|like left lateral strike\|slip faults along with thrusting faults and normal faults. In the middle segment of the Altyn Tagh fault zone, the structures are characterized by the string\|like left lateral strike\|slip faults in the center and reverse thrusting faults on the two sides.

关键词： three\|dimensional deformation uplift mountain building t ranspression Altyn Tagh fault Tibet

Scientific Significance and Site-selection Researches of the First chinese Continental Scientific Deep Drilhole

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Continental Dynamics 1998年第Z1期 3-15页

作者： xu zhiqin, YANG Wenchai, zhang zeming and YANG Tiannan Institute of geology, chinese academy of geological sciences, beijing 100037, China

１ＩｎｔｒｏｄｕｃｔｉｏｎＵｐｔｏｎｏｗｗｅｈａｖｅｎｏｔｋｎｏｗｎｉｎｄｅｔａｉｌｔｈｅＥａｒｔｈｏｎｗｈｉｃｈｗｅｈｕｍａｎｂｅｉｎｇｌｉｖｅ，ａｎｄｅｖｅｎｌｅｓａｂｏｕｔｔｈｅｄｅｅｐｉｎｔｈｅｃｒｕｓｔ．... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＵｐｔｏｎｏｗｗｅｈａｖｅｎｏｔｋｎｏｗｎｉｎｄｅｔａｉｌｔｈｅＥａｒｔｈｏｎｗｈｉｃｈｗｅｈｕｍａｎｂｅｉｎｇｌｉｖｅ，ａｎｄｅｖｅｎｌｅｓａｂｏｕｔｔｈｅｄｅｅｐｉｎｔｈｅｃｒｕｓｔ．Ｈｏｗｅｖｅｒ，ｉｎｆｏｒｍａｔｉ...

关键词： continental scientific drilling site selection UHPM belt Dabie Sulu China

Characteristics　of　Metamorphic　Fluids　in　Zoulang　Nanshan　Caledonian　Accretionary　Subduction　Complex　in　Northern　Qilian　Mountains

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Continental Dynamics 1996年第2期 134-138+138+140-145页

作者： Shen Kun(Shandong Institute of geological sciences, Jinan 250013, China)xu zhiqin xu Huifen and zhang Jianxin(Institute of geology chinese academy of geological sciences, beijing 100037, China)

ＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＭｅｔａｍｏｒｐｈｉｃＦｌｕｉｄｓｉｎＺｏｕｌａｎｇＮａｎｓｈａｎＣａｌｅｄｏｎｉａｎＡｃｃｒｅｔｉｏｎａｒｙＳｕｂｄｕｃｔｉｏｎＣｏｍｐｌｅｘｉｎＮｏｒｔｈｅｒｎＱｉｌｉａｎＭｏｕ... 详细信息

ＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＭｅｔａｍｏｒｐｈｉｃＦｌｕｉｄｓｉｎＺｏｕｌａｎｇＮａｎｓｈａｎＣａｌｅｄｏｎｉａｎＡｃｃｒｅｔｉｏｎａｒｙＳｕｂｄｕｃｔｉｏｎＣｏｍｐｌｅｘｉｎＮｏｒｔｈｅｒｎＱｉｌｉａｎＭｏｕｎｔａｉｎｓ￥ＳｈｅｎＫｕｎ（Ｓｈ...

关键词： subduction complex fluid inclusion

Micro-area Chemical Composition and Preserved P-T Evolution Trace of Phengite in Albite Gneiss from the Donghai Ultrahigh-Pressure Metamorphic Area,East China

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Acta Geologica Sinica(English Edition) 2000年第2期74卷 183-189页

作者： LIU Fulai zhang zeming xu zhiqin YANG Jingsui xu Huifen Institute of geology Chinese Academy of Geological SciencesBeijing 100037China

Study of micro-area chemical compositions indicates that phengite in albite gneiss from hole ZK2304 of the Donghai region has evident compositional zoning. SiO2 and tetrahedrally coord.nated Si contents decrease, and Al2O3, AlIVand AlVIcontents increase gradually from core to rim. However, K2O, MgO and FeO contents basically remain unchanged from core to rim. Accord.ng to P-T estimates obtained from geothermometers and barometers, combined with previous experimental data, the core belt (micro-area I) of phengite was formed at T=637–672°C and P=1.55–1.73 GPa, and the transitional belt (micro-area II) of the phengite were formed at T=594–654°C and P=1.35–1.45 GPa. Toward. the rim belt (micro-area III), the temperature decreased slightly, but the pressure decreased rapidly with T=542–630°C and P=1.12–1.19 GPa. The P-T evolution path record.d by the compositional zoning of phengite is characterized by significant near-isothermal decompression, revealing that the gneiss has undergone high-pressure-ultrahigh-pressure metamorphism. The compositional zoning of the phengite in the albite gneiss may have formed in the geodynamic process of rapid exhumation in the Sulu ultrahigh-pressure metamorphic belt.

关键词： phengite compositional zoning gneiss genetic mechanism Donghai drill hole

LARGEST ALTYN TAGH LITHOSPHERIC SHEAR FAULT IN CENTRAL ASIA

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地学前缘 2000年第S1期7卷 231-232页

作者： xu zhiqin 1, Yang Jingsui 1, zhang Jianxin 1, Jiang Mei 1, Li Haibing 1,Liou J.G. 2[WT5,5”BX](1 Institute of geology,CAGS, 26 baiwanzhuang St., beijing 100037,China,Fax:86\|10\|68311293 2 Department of geological & Environmental sciences,St

The Altyn Tagh fault (ATF) extending in NEE—SWW direction lying at the northwestern boundary of Qinghai—Tibet plateau is the largest strike\|slip fault in Central Asia. On the basis of recent geologic mapping and detailed study of lithotectonic characteristics for the paleotectonic units at the two sides of the Altyn Tagh Fault ( Altun Mt. to west and the Qilian Mt. to east ) we propose that the paleotectonic units in the Altun Mt. can be correlated with those in the Qilian Mt. assuming 400km left\|lateral displacement for the Altyn Tagh fault. Natural seismic data across the Altun Mt. indicate that the Altyn Tagh fault is a lithospheric shear fault and the lithospheric shearing is probably related to southward.intracontinental oblique subduction of the Tarim terrane beneath the Altun Mt.1\ Comparison of the major paleotectonic units at the two sides of the Altyn Tagh fault\;(1) The Alxa\|Dunhuang Massif:The Alxa massif lying at the southern margin of the Sino\|Korean craton consists mainly of an Early Proterozoic basement including high\|grade and middle\|grade metamorphic rocks, which were intruded by granite at 1719Ma. The Paleozoic passive margin sediments is well developed. In the Altun Mt., the Early Proterozoic and late Archean basement of the Duhuang massif includes high\|grade and middle\|grade metamorphic rocks dating 2789Ma (Sm\|Nd method) and 2405Ma (U\|Pb method).

关键词： lithospheric shear fault paleotectonic unit seismic the Altyn Tagh fault Central Asia

The Zoulang Nanshan Caledonian Subduct ion Complex in the Northern Qilian Mountains and Its Dynamics

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Acta Geologica Sinica(English Edition) 1994年第3期68卷 225-241页

作者： xu zhiqin, xu Huifen, zhang Jianxin, Li Haibing, Zhu Zhizhi, Qu Jingchuan,Institute of geology, chinese academy of geological sciences, beijingChen Daizhang, Chen Jinlu, China University of Geosciences, beijingand Yang KaichunNo. 2 Q ilian geological Party, Bureau of geology and Mineral Resources of Q inghai Province, Q ilian County, Q inghai chinese academy of geological sciences Beijing China

The front of the Zoulang Nanshan Caledonian volcanic island arc zone in the northern Qilian Mountains is a forearc accretionary terrane, composed of multiple accretionary volcanic island arcs, flysch accretionary wedges,high-pressure metamorphosed detachment zones and remnants of ophiolites. It resulted from the northeastward.subduction of the Early Palaeozoic Qilan oceanic crust beneath the Alxa block. High-pressure metamorphism, which occurred during the subduction, progressed through three stages: the initial stage of medium T-high P,the main stage of temperature decrease and pressure increase, and the lag stage of pressure decrease and temperature increase. Finally the paper presents a retrotrench subduction dynamic model indicative of northward.subduction of the central Qilian block and southward.accretion of the Alxa block during the period of 450-500 Ma.

关键词： subduction complex accretionary terrane multiple structure retrotrench subduction dynamics

AGE OF THE ALTYN TAGH STRIKE—SLIP FAULT

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地学前缘 2000年第S1期7卷 208-209页

作者： Li Haibing 1, Yang Jingsui 1, xu zhiqin 1, Wu Cailai 1, zhang Jianxin 1, Wan Yushen 1, Shi Rendeng 1, Juhn G. Liou 2,Trevor R. Ireland 2 (1 Institute of geology, chinese academy of geological sciences, beijing 100037, China 2 Department of

A 100～500m\|wide mylonite zone in the Altun Group of Lower Proterozoic age was discovered along the Altyn Tagh strike\|slip fault. The zone is mainly composed of amphibolitic and granitic mylonites. The planar joints of the rocks strike in NE70 and dip steeply (nearly vertical), coincident with the striking of Altyn Tagh fault zone, and their stretched lineations are nearly horizontal. Shear strains are well developed and show sinistral sheared. The amphibolitic and granitic mylonites are most probably the products of deep\|seated melting caused by sinistral strike\|slip shearing as suggested by the evidence below: (1) The migmatization is intensely developed and spatially controlled by the shear zone, and the rock has a set of NNE perspective foliation which is in accord.with the direction of the Altyn Tagh strike\|slip fault zone. (2) The recrystallized hornblende aggregate is distributed in band with obvious nebulous texture, indicating the characteristics of anatexis, and the hornblendes are oriented and form the nearly horizontal stretching lineation; some hornblendes have titanite inclusions, and magmatic long\|columnar zircons are in directional arrangement.(3) The banded felsic material is developed, and the plagioclase is characteristic of high\|temperature plastic deformation and shows sinistral shear stain. (4) In mylonites, all the axis C fabric of quartz shows the feature of sinistral shearing and the majority is generally middle to low temperature fabric, but there also exists high temperature fabric, which suggests that high temperature shearing occur in the early stage of strike\|slip deformation and it is characterized by middle to low temperature shearing at the beginning of anatexis or in the late stage of the deformation. (5) On the XZ plane of mylonite and mylonitized rocks, there exists the consistent sinistral shear stain, which suggests the products of the same strike\|slip *** were separated from three samples of mylonitized gra

关键词： Altyn Tagh fault Tibet plateau SHRIMP dating mylonite