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Acta Geochimica 2007年第3期26卷 305-311页

作者： LAI Shaocong, QIN Jiangfeng, LI Yongfeng, and LIU xin state Key laboratory of continental {3., department of geology, northwest university, xi’an 710069, china state Key laboratory of continental {3. Department of GeologyNorthwestUniversityXi'an 710069China

Neogene volcanic rocks in the Belog Co area, Qiangtang, northern Tibet, are represented by a typical intermediate-basic and intermediate alkaline rock association, with latite-trachyte as the main rock type. The results of chemical analysis are: SiO2=52%–62%, Al2O3.15%, Na2O/K2O>1 and MgO3.3.%. In addition, the volcanic rocks are LREE-enriched with LREE/HREE=10–13. (La/Yb)N=15–19, and show a weak negative Eu anomaly with δEu=0.71–0.89. The close relationship between Mg# and SiO2 and the co-variation of the magmatophile elements and ultra-magmatophile elements such as La/Sm-La and Cr-Tb indicate that this association of volcanic rocks is the product of comagmatic fractional crystallization. The rock association type and lower Sm/Yb values (Sm/Yb=3.23.3.97) imply that this association of volcanic rocks should have originated from partial melting of spinel lherzolite in the lithospheric mantle. On the other hand, the weak negative Eu anomaly and relative depletion in Nb, Ta and Ti reflect the features of terrigenous magma. So the Neogene Belog Co alkaline volcanic rocks should be the result of partial melting of the special crust-mantle transition zone on the Qinghai-Tibet Plateau.

关键词： major and trace elements Cenozoic volcanic rock mantle-crust transition zone Qinghai-Tibet Plateau

Thoughts on studies of china continental geology and tectonics

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Progress in Natural Science:Materials International 2006年第10期16卷 1022-1026页

作者： ZHANG Guowei, GUO Anlin and YAO Anping (Ministry of Education Key laboratory of continental dynamics,{3., northwest university, xi’an 710069, china) [a]Ministy if Education Key laboratory of dynamics Department of Geology Northwest University Xi an China

As an important part of the global continents, china continent has long been situated in the peculiar tectonic position and experienced extremely complicated activities, which resulted in the regional unique characteristics for china continent on the global common geological background. These characteristics contain abundant information regarding scientific key issues of modern geological frontier. Thus, china continent can be a natural {3. and excellent arena for the modern geosciences. The modern earth sciences have started entering the era featured with earth systematic science and beyond plate tectonics. How to take the regional advantage and exploit the treasure resource to participate the new theoretical and methodological creation is a historic opportunity and great challenge we are facing. This paper generalizes research priorities in four fields on china continental geology and tectonics for discussion. They are: china continental tectonics and dynamics; Mesozoic-Cenozoic crustal deformation and deep-seated processes in china continent and the adjacent regions; deep-seated dynamic background and evolutionary trend of crustal tectonic activities on the time scale of human existence; deep-seated background and processes of conjunction and transformation of different tectonic systems.

关键词： china continental geology and continental tectonics plate tectonics continental dynamics key scientific issues.

Identification of 3.5 Ga detrital zircons from Yangtze craton in south china and the implication for Archean crust evolution

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Progress in Natural Science:Materials International 2006年第6期16卷 663-666页

作者： LIU xiaoming, GAO Shan, LING Wenli, YUAN Honglin and HU Zhaochu (National Key laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, china university of Geosciences, Wuhan 43.074, china Key laboratory of continental dynamics, department of geology, northwest university, xi' an 710069, china) [a]National Key laboratory of Geological Processes and Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan China [b]Key laboratory of continental dynamics Department of Geology Northwest University China

The LA-ICP-MS U-Pb dating of hundreds of detrital zircon grains from the Sinian sandstones of Liantuo formation and tillites of Nantuo formation at Sanxia area in Yichang identified 3.19-3.08 Ma zircon grains. Their 207Pb/206Pb and 206Pb/23.U ages show excellent agreement (concordia degree 99%-100% ). Their CL images exhibit well-developed oscillatory zoning and the Th/U ratios are within 0.46-0.76, implying that they are igneous zircons which formed during middle-early Archean. These zircons are the oldest ones discovered in Yangtze craton until now. However, the detrital zircons with ages older than 3. 3.Ga in the metamorphic rocks of Kongling group were not found by further investigation, which suggests the presence of crust older than high-grade metamorphic Kongling terrain in Yangtze craton.

关键词： early Archean detrital zircon zircon dating Yangtze craton.

Northernmost paleo-tethyan oceanic basin in Tibet:Geo-chronological evidence from ^(40)Ar/^(3.)Ar age dating of Dur'ngoi ophiolite

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Chinese Science Bulletin 2001年第14期46卷 1203-1205页

作者： CHEN Liang, SUN Yong, PEI xianzhi, GAO Ming, FENG Tao, ZHANG Zhongqing & CHEN Wen1. laboratory of continental dynamics,{3., xi’an 710069, china 2. department of geology,{3., xi’an, 710069, china 3. Institute of geology, Chinese Academy of Geological Sciences, Beijing, 10003., china laboratory of continental dynamics Northwest University Xi’an China department of geology Northwest University Xi’an China Institute of geology Chinese Academy of Geological Sciences Beijing China

Whole rock 40Ar/3.Ar age dating has been conducted on a basalt sample from Dur’ngoi ophiolite, Qinghai Province, which was reported to be the northernmost pa-leo-tethyan oceanic basin in Tibet. A high temperature pla-teau age (3.5.3.7.9 Ma) with an isochorn age (3.6.6±7.1 Ma) has been obtained, representing the eruption time of oceanic crust Considering related geological settings, the new age provides constraints on the northernmost pa-leo-tethyan suture zone in Tibet and the tectonic evolution of Paleo-tethys in Northeast Tibet and adjacent areas.

关键词： Dur’ngoi ophlolite 40Ar -3.Ar age Paleo-tethys.

The microtine distribution and its environmental significance since the Middle Pleistocene in Zhangping Caves of the Qinling Mountains

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Science china Earth Sciences 2008年第2期51卷 294-299页

作者： LI Yongxiang1 & XUE xiangXu1,2 1 state Key laboratory of continental {3., department of geology, northwest university, Institute of Cenozoic geology and Environment, xi’an 710069, china 2 Institute of Earth Environment, state Key laboratory of Loess and Quaternary geology, Chinese Academy of Sciences, xi’an 710075, china 1. state Key laboratory of continental {3. Department of Geology Northwest University Institute of Cenozoic Geology and Environment Xi’an 710069 China 2. Institute of Earth Environment State Key Laboratory of Loess and Quaternary Geology Chinese Academy of Sciences Xi’an 710075 China

Three microtine species are recovered from the Zhangping Caves of the Qingling Mountains, namely Microtus oeconomus, Caryomys inez and Caryomys eva. They are climate-sensitive ones with different ecological habits, therefore their distribution well corresponds to environmental variations. Statistical comparison of the distribution of fossil microtines and their counterparts nowadays displays that the climate variation of the studied area and its contiguity since the middle Pleistocene are: warm and humid at 493.ka ago, cool and humid at 259 ka ago―cold and humid at 205 ka ago―cool and humid at 28 ka ago, and warm and dry at present.

关键词： environmental variation since Middle Pleistocene microtine fossils Zhangping Caves of the Qinling Mountains

Constraints on the late Mesozoic regional angular unconformity in West Liaoning-North Hebei by LA-ICP-MS dating

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Progress in Natural Science:Materials International 2008年第11期18卷 1395-1402页

作者： Hong Zhang~(a,b,*) Wenmin Guo~a xiaoming Liu~b a College of Mechanical and Energy Engineering,Jiangsu Polytechnic university,Changzhou 213.16,china b Key laboratory of {3. dynamics,department of geology,northwest university,xi’an 710069,china College of Mechanical and Energy Engineering Jiangsu Polytechnic University Changzhou 213016 China Key laboratory of continental dynamics Department of Geology Northwest University Xi’an 710069 China

The angular unconformity between the Tuchengzi Formation and the Zhangjiakou Formation in the Chengde area is commonly regarded as the direct evidence of boundary between Jurassic and Cretaceous systems,and as the evidence of tectonic transformation interfaces in Mesozoic Era in the West Liaoning-North ***,the lower boundary age of the Zhangjiakou Formation in the Chengde was to be thought about 13. Myr in the *** on the detailed study and systematic sampling in Yixian-Beipiao,Lingy- uan,Chengde and Luanping areas in the field,the authors obtained the following isotopic ages by means of LA-ICP-MS dating:In the Lingyuan area,the Zhangjiakou Formation and the Yixian Formation are in angular unconformable contact;the age range of the Zhangjiakou Formation volcanic rock is from 13. to 13. Myr(seven samples),and that of the Yixian Formation volcanic rock is from 126 to 121 Myr(eleven samples).In the Luotuoshan of Chengde,the Tuchengzi Formation and the Zhangjiakou Formation are in angu- lar unconformable contact;the age at the lower Zhangjiakou Formation is about 124 Myr(one sample),which reflects that the age range of the lower Zhangjiakou Formation is from 129 to 124 Myr combined with the previous *** the Luanping basin,there is the larg- est sediment gap in upper Mesozoic,whose lower boundary age is confined in 13. to 13. *** the Yixian-Beipiao area,the second Member of the Yixian Formation,making up more than 3.4 thickness of the Yixian Formation,was formed in 126 to 119 Myr,and the age of the Yixian Formation at the bottom is about 13. ***,the upper boundary age of the Tuchengzi Formation is about 13. Myr in the West Liaoning-North Hebei *** on the above isotopic data combined with the geological characteristics in the field in the West Liaoning-North Hebei region,it reflects that there was a widespread tectonic event in the period of 13. to 126 Myr (mainly in 13.-126 Myr)in the West Liaoning-North Hebei,and it formed the

关键词： Dating LA-ICP-MS Angular unconformity Interface of tectonic transformation West Liaoning-North Hebei

Ultra-high pressure metamorphism of granitic gneiss in the Yinggelisayi area, Altun Mountains, NW china

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Science china Earth Sciences 2004年第4期47卷 338-346页

作者： LIU Liang, SUN Yong, LUO Jinhai, WANG Yan, CHEN Danling & ZHANG Anda The Key laboratory of continental dynamics, Ministry of Education,{3. of geology, northwest university, xi抋n 710069, china The Key laboratory of continental dynamics Ministry of Education Department of Geology Northwest University Xi’an 710069 China

A study on petrography and mineral chemistry of granitic gneiss from the Yinggeli-sayi area in the Altun Mountains of the northwestern china demonstrates that the granitic gneiss experienced a complicated multi-stage metamorphism. The peak-stage mineral assemblage is garnet+perthite(before exsolution)+titanite(before exsolution)+kyanite+zoisite +quartz/ coesite clinopyroxene with minor apatite and rutile. The exsolution of rod-like plagioclase +amphibole is contained within the core part of coarse-grained titanite, and the Si value per unit formula of the titanite is estimated to be 1.03.—1.047, which implies that the titanite contains Si with six-fold coordination and the precursor titanite is hence of supersilicic titanite and suggests that the CaSi2O5 component in the titanite is 3.1%—4.7%. The P-T condition of peak metamorphism is estimated to be 3.7—4.3.Pa at 1000. High-Al titanite inclusions are also found in the garnet. All of these suggest that the granitic gneiss underwent UHP metamorphism. The granitic gneiss has SiO2 content (> 70%), Al2O3.(12.58%—14.08%), high K2O content (>5%) with Na2O/K2O ratio of 0.4—0.6, LREE-enriched patterns with (La/Yb)N ratio of 4.3.9.1 and large negative Eu anomaly (d Eu = 0.06—0.59), which indicate that the protolith of the granitic gneiss is the product of anatexis of the middle or upper crustal rock. The UHP granitic gneiss, together with the inter-beds of UHP metamorphic garnet lherzolite and garnet-bearing intermediate-basic gneiss in the outcrops, suggests that they all might undergo continental deep subduction, which will have im-portant bearing for further discussion of the dynamic mechanism of the formation and exhuma-tion of the rocks in this region.

关键词： Altun Mountains, granitic gneiss, supersilicic titanite, UHP metamorphism, continental deep subduction.

Multistage evolution of continental collision orogen:A case study for western Dabie orogen

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Chinese Science Bulletin 2009年第15期54卷 2568-2579页

作者： WU YuanBao state Key laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, china {3. of Geosciences, Wuhan 43.074, china state Key laboratory of continental dynamics, department of geology, northwest university, xi’an 710069, china state Key laboratory of Geological Processes and Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China state Key laboratory of continental {3. Department of Geology Northwest University Xi’an 710069 China

The foramtion and evolution of collisional orogen is a prominent feature along convergent plate margins, and is generally a complex process. This article presents an integrated study of zircon genesis, U-Pb age and Lu-Hf isotope composition as well as geological characteristics for the western Dabie orogen to constrain its multi-stage evolution history. The results suggest that the formation of oceanic crust in the Huwan area was constrained at ca. 400―43. Ma, which was slightly later than the collision of the northern Qinling with the North china Block. It formed in a marginal basin in the northern margin of the Yangtze Block. The peak metamorphism of eclogite in the Huwan area occurred at ca. 3.0 Ma, and the timing of the initial exhumation of oceanic eclogite was about 270 Ma. The high to ultrahigh pressure (HP-UHP) metamorphic rocks in the xinxian and the Hong'an metamorphic zones have the same ages and natures as those of the HP-UHP metamorphic rocks in the other Dabie-Sulu terrains, and also have experienced multi-stage exhumation, and thus can be taken as a coherent part of the Dabie-Sulu orogen. Therefore, the Qinling-Dabie-Sulu orogen is a typical multi-stage continental collision orogen, with an amalgamation process extending more than 200 Ma.

关键词：大别造山带大陆碰撞西部演变超高压变质岩碰撞造山带苏鲁造山带变质岩区

LA-ICP-MS dating of Zhangjiakou Formation volcanic rocks in the Zhangjiakou region and its geological significance

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Progress in Natural Science:Materials International 2008年第8期18卷 975-981页

作者： Hong Zhang a,b,*, Mingxin Wang a, xiaoming Liu b a College of Mechanical and Energy Engineering, Jiangsu Polytechnic university, Baiyun District, Changzhou, Jiangsu 213.16, china b Key laboratory of {3. dynamics, department of geology, northwest university, xi’an 710069, china College of Mechanical and Energy Engineering Jiangsu Polytechnic University Baiyun District Changzhou Jiangsu 213016 China Key laboratory of continental dynamics Department of Geology Northwest University Xi’an 710069 China

The geological cross section of the Zhangjiakou Formation is originally established in the Zhangjiakou region. From the dating of four samples from typical cross sections of the Zhangjiakou Formation in the Zhangjiakou region, the age range is found to be mainly from 143.0 ± 3.7 Myr to 13..1 ± 1.4 Myr, which almost equals the sum of the age range of the Zhangjiakou Formation (13.-13. Myr) and that of the Tuchengzi Formation (143.13. Myr) in the Luanping region, and the Zhangjiakou and Tuchengzi Formations in Zhangjiakou-Luanping of North Hebei are found to be conformable. The evidence above indicates that the Zhangjiakou and Tuchengzi Formations, which are distributed in Zhangjiakou-Luanping, were formed under the same geological setting. Volcanic activity was earlier and longer (143.13. Myr) in the western region (Zhangjiakou) than that in the eastern region (Luanping). The "Zhangjiakou Formation"in Chengde and Pingquan formed in the period in which the Yixian Formation in West Liaoning formed, so should be renamed the Yixian Formation.

关键词： Zhangjiakou Formation Volcanic rocks LA-ICP-MS Dating Zhangjiakou region

Petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central china: Constraints from geochemistry and melt inclusions

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Science china Earth Sciences 2005年第8期48卷 1146-1157页

作者： SU Li1,2, SONG Shuguang3.& ZHOU Dingwu1 1. Key laboratory of continental dynamics of the Ministry of Education,{3., northwestern university, xi’an 710069, china 2. The Geological Lab Center, china university of Geosciences (Beijing), Beijing 100083. china 3. Key laboratory of Orogenic Belts of the Ministry of Education,{3., Peking university, Beijing 100871, china 1. Key laboratory of continental dynamics of the Ministry of Education Department of Geology Northwestern University 710069 Xi’an China 2. The Geological Lab Center China University of Geosciences 100083 (Beijing)Beijing China 3. Key laboratory of Orogenic Belts of the Ministry of Education Department of Geology Peking University 100871 Beijing China

The Songshugou dunite body, which occupies an area of about 20 km2, is the largest ultramafic massif in the eastern Qinling orogenic belt, Central china. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. Petrography, mineral composition, major and trace ele-ments and primitive melt inclusions have been investigated in this paper; all revealed that this dunite body is the product of melt-rock interaction by porous percolation flow. In comparison with dunite sills or veins in harzburgite from the basal part of Oman ophiolite, this dunite body is characterized by lower contents of Al2O3. CaO and HREE but higher content of highly incom-patible elements and Zr and Hf. The LREE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale porous percolation flow of high-MgO melts within depleted mantle peridotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle super-plume in Neo-Proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.