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Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South china

Science china Earth Sciences 2006年第3期49卷 225-241页

作者： ZUO Jingxun1,2, TONG Jinnan3. QIU Haiou4 & ZHAO Laishi3.1. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, china 2. Henan Institute of geological Survey, Zhengzhou 450007, china {3., wuhan 4.0074. china 4. Faculty of Material Sciences and Chemical Engineering, china university of geosciences, wuhan 4.0074. china 1. Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China 2. Henan Institute of geological Survey Zhengzhou 450007 China 3. state key laboratory of geological processes and mineral resources at china university of geosciences Wuhan 430074 China 4. Faculty of Material Sciences and Chemical Engineering China University of Geosciences Wuhan 430074 China

Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South china, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13. background values are intensively controlled by palaeogeographic environment. In general, δ 13. values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the Induan- Olenekian boundary and the Lower Triassic-Middle Triassic boundary.

关键词： Lower Triassic, carbon isotope compositions, palaeogeography, volcanic eruptions, Lower Yangtze Region.

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Petrogenesis of Indosinian volcanic rocks in Songpan-Garze fold belt of the northeastern Tibetan Plateau:New evidence for lithospheric delamination

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Science china Earth Sciences 2010年第9期53卷 1316-1328页

作者： CAI HongMing1,2, ZHANG HongFei1,2, XU WangChun1,2, SHI ZhangLiang1,2 & YUAN HongLin3.1 state key laboratory of {3. processes and mineral resources, wuhan 4.0074. china 2 Faculty of Earth Sciences, china university of geosciences, wuhan 4.0074. china 3.state key laboratory of Continental Dynamics, Northwest university, Xi’an 710069, china 1. state key laboratory of {3. processes and mineral resources Wuhan 430074 China2. Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China3. State Key Laboratory of Continental Dynamics Northwest University Xi’an 710069 China

In the Songpan-Garze fold belt of the northeastern Tibetan Plateau, an Indosinian lithospheric delamination model has been proposed, based on previous investigation of widespread granitoids. However, this model lacks comparable information from volcanism in the area. During the Indosinian delamination in the Songpan-Garze fold belt, whether partial melting of litho- spheric mantle taken place is debated. This paper reports U-Pb zircon LA-ICP-MS ages, geochemical and Sr-Nd-Hf isotopic compositions from the Aba and Wasai calc-alkaline volcanic rocks in the central Songpan-Garze fold belt. Obtained magma crystallization ages are 210±3.Ma for the Aba andesite and 205±1 Ma for the Wasai andesite. These are consistent with magma crystallization ages of the late Indosinian granitoids in the Songpan-Garze fold belt that formed in a post-collisional tectonic setting. The Aba and Wasai andesites have distinct geochemical singnatures. The former has higher Al2O3. K2O, Rb but lower Na2O, Ba and Sr contents, suggesting differences in their magmatic evolution. The Aba andesites have ISr values of 0.7070-0.7076 and εNd(t) values of -3.9 to -5.3. and the Wasai andesites have ISr values of 0.7075-0.7077 and εNd(t) values of -3.6 to -3.9. Zircons show εHf(t) values of -3.7 to 0.3.for the Aba andesites and -2.7 to 5.5 for the Wasai andesites. Geochemical and Sr-Nd-Hf isotopic compositions indicate that fractional crystallization and crustal assimilation processes are not key roles for their magma evolution, implying that their chemical compositions are those of primary melts. We suggest that the magma of the Aba andesites originated predominantly from a crustal source, with a minor mantle-derived component. The source region of the magma was likely at the crust-mantle boundary. The magma of the Wasai andesites resulted from partial melting of lithospheric mantle, which was probably metasomatized by fluids so that it was amphibole bearing. The petrogenesis of the Aba and Wasai andesite

关键词： volcanism U-Pb dating geochemistry petrogenesis lithospheric delamination Songpan-Garze fold belt

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Geochemistry of the high-Mg andesites at Zhangwu, western Liaoning: Implication for delamination of newly formed lower crust

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Science china Earth Sciences 2007年第12期50卷 1773-1786页

作者： HUANG Hua1,GAO Shan1,2,HU ZhaoChu1,LIU XiaoMing2 & YUAN HongLing2 1 state key laboratory of {3. processes and mineral resources,china university of geosciences,wuhan 4.0074.china 2 state key laboratory of Continental Dynamics,Department of Geology,Northwest university,Xi’an 710069,china 1. state key laboratory of {3. processes and mineral resources China University of Geosciences Wuhan 430074 China 2. state key laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China

Ten volcanic samples at Zhangwu,western Liaoning Province,North china were selected for a sys-tematic geochemical,mineralogical and geochronological study,which provides an opportunity to ex-plore the interaction between the continental crust and mantle beneath the north margin of the North china *** one basalt sample(SiO2= 50.23.),the other nine samples are andesitic with SiO2 contents ranging from 53. to 59%.They have relatively high MgO(3.4%―6.1%,Mg#=50―64) and Ni and Cr contents(Ni 27×10?6―197×10?6,Cr 51×10?6―478×10?6).Other geochemical characteristics of Zhangwu high-Mg andesites(HMAs) include strong fractionation of light rare earth elements(LREE) from heavy rare earth elements(HREE),and Sr from Y,with La/Yb greater than 15,and high Sr/Y(3.― 115).Zircons of andesite YX270 yield three age groups with no Precambrian age,which precludes ori-gin of the Zhangwu HMAs from the partial melting of the Precambrian *** oldest age group peaking at 253.Ma is interpreted to represent the collision of the Siberia block and the North china block,resulting in formation of the Central Asian orogenic belt by closure of the Mongol-Okhotsk *** intermediate age group corresponds to the basalt underplating which caused the wide-spread coeval granitoids in the North china craton with a peak 206Pb/23.U age of 172 *** youngest age group gives a 206Pb/23.U age of 126±2 Ma,which is interpreted as the eruption age of the Zhangwu *** high 87Sr/86Sri(126 Ma)>0.706 and low εNd(t)= ?6.3.―?13.99 of the Zhangwu HMAs are distinct from slab *** common presence of reversely zoned clinopyroxene phenocrysts in the Zhangwu HMAs argues against the origin of the Zhangwu HMAs either from melting of the water saturated mantle or melting of the lower *** light of the evidence mentioned above,the envisaged scenario for the formation of the Zhangwu HMAs is related to the basaltic underplating at the base of the crust,which led to the thickening of the lower crust and

关键词： Zhangwu HMAs, basalt underplating, newly formed lower crust, delamination, North china craton

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Multiple Successions of Soliation Development in Shallow Versus Deep Orogenic Regimes and Their Relationship to Regional Folding

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地学前缘 2009年第S1期16卷 89-90页

作者： Hui Cao state key laboratory of {3. processes and mineral resources Institute of Land resources and High Techniques,china university of geosciences(Beijing),Beijing 100083.china.

With the realization that rocks with a schistosity parallel to bedding(S0 parallel S1)have undergone lengthy histories of deformation that predate the obvious first deformation(*** et al.,2003. Sayab,2006;Yeh,2007)came recognition that large scale regional folds can form early during this process and be preserved throughout orogenesis(e.g.,Ham & Bell,2004;Bell & Newman,2006).This history is lost within the matrix because of reactivational shear

关键词： orogenesis axial planes of folds porphyroblasts foliation intersection/inflection axes(FIAs)

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Metallogenic epoch and genesis of the gold deposits in Jiaodong Peninsula, Eastern china: a regional review

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Progress in Natural Science:Materials International 2007年第2期17卷 138-143页

作者： YANG Liqiang, DENG Jun, GE Liangsheng, WANG Qingfei, ZHANG Jing, GAO Bangfei, JIANG Shaoqing and XU Hao ( state key laboratory of {3. processes and mineral resources, china university of geosciences, Beijing 100083. china key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, china university of geosciences, Beijing 100083. china) [a]state key laboratory of {3. processes and mineral resources China University of Geosciences Beijing China [b]key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing China

Gold deposits are characterized by multi-sources, superimposition, large scale and temporal-spatial concentration in Jiaodong Peninsula, Eastern china. In this paper, we review the history and the development of the study on metallogenic chronology and genesis of gold deposits, summarize the main features of superimposed metallogenesis, provide evidence of the Mesozoic complex metallogenic system, and point out some problems for further research of Jiaodong gold deposit cluster from a regional view. Although gold deposits are different in genetic types, ore-forming materials and geological settings, our research indicates that the accumulation and emplacement of the ore-forming materials are temporally-spatially concentrated on a large scale, and the main metallogenic epoch of Jiaodong gold deposits was concentrated in Mesozoic. Metallogenic chronology and geological-geochemical data indicate that there are two periods of gold {3.izations occurred in 13.-110 Ma and 90-80 Ma respectively in Jiaodong ore cluster. The gold deposit cluster results from the superimposition of the polygenetic {3.ization, and further study is needed to investigate the formation and evolution of the Mesozoic complex metallogenic system.

关键词： superimposed metallogenic system Mesozoic Jiaodong ore cluster.

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Progress in researching into the transition of the Mesozoic tectonic systems in southeast china

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Progress in Natural Science:Materials International 2006年第6期16卷 563-572页

作者： YU Xinqi, WU Ganguo, ZHANG Da, ZHANG Xiangxin, DI Yongjun, ZANG Wenshuan, WANG Qunfeng and HUANG Huojian (state key laboratory of {3. processes and mineral resources, china university of geosciences, Beijing 100083. china key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, china university of geosciences, Beijing 100083. china) [a] state key laboratory of {3. processes and mineral resources Chine University of Geosciences Beijing China [b] key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing China

This paper presents the latest progress made on the research of Mesozoic tectonic system transition from the E-W paleo-Tethyan tectonic domain into NE-NNE western Pacific domain in southeast china. Tectonism of the west Pacific domain began at middle Jurassic (J2) and formed a set of NE-trending structures, non-coaxially overprinting on E-trending tectonic belts which may be early and coevally produced by the paleo-Tethyan domain. Thus began the tectonic domain transition from the E-trending paleo-Tethyan to the NE-trending Pacific and fully finished at the early Cretaceous. The eastern Nanling area was a junction zone of the transition at middle Jurassic (J2),and ever since the junction zone might obliquely migrate to the coastal region, where is the east part of this study area. To the north of the Nanling area, the Ganjiang Fault Zone was the boundary between two tectonic domains. Corresponding to the transition of tectonic system, the geodynamics of SE china changed from a compressional system to an extensional system, which continued until the end of Mesozoic-Tertiary.

关键词： transition of tectonic system non-coaxial overprint obliquely migrate Mesozoic paleo-Tethyan tectonic domain west Pacific tectonic domain southeast china.

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Research advances in the Mesozoic tectonic regimes during the formation of Jiaodong ore cluster area

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Progress in Natural Science:Materials International 2006年第8期16卷 777-784页

作者： DENG Jun, YANG Liqiang, GE Liangsheng, WANG Qingfei, ZHANG Jing, GAO Bangfei, ZHOU Yinghua and JIANG Shaoqing (state key laboratory of {3. processes and mineral resources, china university of geosciences, Beijing 100083. china key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, china university of geosciences, Beijing 100083. china) [a]state key laboratory of {3. processes and mineral resources China University of Geosciences Beijing China [b]key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing China

Based on research advances of the tectonic regime in Jiaodong ore cluster area and the related tectonic regime transformation in Mesozoic era in the eastern region of North china, in this paper, we first summarize some key problems required to be studied further on. Then we suggest an approach to dealing with these problems. It is known that the gold deposits in Jiaodong ore cluster area, which are of different mineralization styles, spatial distributions and {3. settings, might be as a result from one or more geologic events in Mesozoic. Till now, this kind of research on the temporal evolution and spatial migration sequence, especially on the geodynamic mechanism of the above events, is far from sufficient. Moreover, quantitatively describing the action mode and the temporal-spatial framework of tectonic dynamic regimes and formulating the relative contribution of every tectonic dynamic regime for the metallogensis are still challenges to the geologists studying on the formation of Jiaodong ore cluster area. According to the interpretation of the regional tectonic analysis, the structural dynamics, the observation and the exploration of the mineralization network, we propose a {3.-physical-chemical model with some constraints originated from the comprehensive analysis. We then use this model to simulate the coupled processes of the structural deformation, thermal transport, fluid flow and the chemical reaction. The obtained results indicate that the model is efficient in further analyzing the temporal-spatial evolutional trail of the tectonic regime in Jiaodong ore cluster area and in further understanding the nature of the mass metallogensis.

关键词： tectonic regime Mesozoic era Jiaodong ore cluster area genesis metallogenic system.

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Analytical method of Cr stable isotope and its application to water pollution survey

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Chinese Science Bulletin 2010年第7期55卷 664-669页

作者： GAO YongJuan 1,2,3.MA Teng 4,5,LING WenLi 1,2,LIU CunFu 4,5 & LI Li 4,5 1Faculty of Earth Science,china university of geosciences,{3. 4.0074.china 2state key laboratory of geological processes and mineral resources,china university of geosciences,{3. 4.0074.china 3.Graduate School,china university of geosciences,{3. 4.0074.china 4 Biogeological and Environmental Geology laboratory of Ministry of Education(china university of geosciences) ,{3. 4.0074.china 5 Sino-Hungary Joint laboratory of Environmental Sciences and Health,china university of geosciences,{3. 4.0074.china Faculty of Earth Science China University of Geosciences Wuhan 430074 China state key laboratory of {3. processes and mineral resources China University of Geosciences Wuhan 430074 China Graduate School China University of Geosciences Wuhan 430074 China Biogeological and Environmental Geology laboratory of Ministry of Education (china {3. of geosciences) Wuhan 430074 China Sino-Hungary Joint laboratory of Environmental Sciences and Health China University of Geosciences Wuhan 430074 China

High Cr(VI) concentration is a potential serious risk to environment and ecologic ***,it is essential to effectively monitor Cr contamination in water systems and scientifically evaluate its evolution trend.A new method of in-situ tracer technique by Cr isotopic analysis for quantitatively estimating Cr-contamination and its regional evolution in natural waters as well as a case application are reported in this *** on documented literatures,an experimental procedure for chemical separation and purification of Cr in water samples and its analytical method for Cr isotopic measurement by thermal ionization mass spectrometry(TIMS) are *** samples collected around a chemical factory in Hubei Province were analyzed by this *** samples showδ53.r values ranging from-1.7‰to 7.3.and an elevating trend with an increasing in distance from the sampling site to pollution source.A functional correlation following Rayleigh fractionation law was established between sample'sδ53.r value and its extent of Cr *** study suggests that Cr isotopic analysis is an effective method to reveal the spatial distribution and its evolution trend of Cr contamination in the regional water *** is thus helpful to assessing the self-purifying ability of local water system according to Cr isotopic fractionation.

关键词：铬(VI) 水污染调查稳定同位素应用同位素分析供水系统演变趋势示踪技术

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Experimental remolding on the caprock's 3. strain field of the Indosinian-Yanshanian epoch in Tongling deposit concentrating area

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Science china Earth Sciences 2005年第7期48卷 863-874页

作者： DENG Jun1,HUANG Dinghua2,WANG Qingfei1,WAN Li1,SUN Zhongshi3.YANG Liqiang1 & GAO Bangfei1 1. state key laboratory of {3. processes and mineral resources,china university of geosciences,Beijing 100083.china 2. Faculty of Earth Sciences,china university of geosciences,wuhan 4.0074.china 3. Department of Earth Sciences,Jilin university,Changchun 13.061,china state key laboratory of {3. processes and mineral resources China University of Geosciences Beijing 100083 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Department of Earth Sciences Jilin University Changchun 130061 China

Based on field observations and rheology analysis, we perform one analogue experiment and remold the 3. structural frame of Tongling deposit concentrating area firstly. Then we disassemble and dialyze the 3. structures of the model using the methods of "slicing" and "stripping". A series of sliced planes vertical to the fold hinges show similar landscapes of that in the drill hole profiles. Meanwhile, layer stripping analysis indicates that the deformation features of each layer in the model are qualitatively analogical to those obtained from field observations. Through contrasting the 3. structure between the experimental model and the field phenomena, we verify the following 3. deformation features of the caprock in this area: (1) the Tongling area mainly consists of three series of NE S-typed fold groups; (2) in the uniform stress field, the incoherent folds universally develop in different positions, along different axes as well as in different strata; (3. the faults propagate upward which are mostly inter-bedded detachment faults, while the fold amplitudes decrease while going deeper; and (4) the folds and cleavages are highly developed in the Silurian System indicating that the deformation effect of the Indosin-ian-Yanshanian structural layer terminates at this layer, which suggests that the Silurian System is the crucial layer for the inversion between brittle and plastic deformation domains and the underlying strata are subject to the control of another deformation system with distinct properties.

关键词： Tongling deposit concentrating area Indosinian-Yanshanian epoch 3. structural frame of the caprock analogue experiment slicing and stripping analysis structural model.

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Nb/Ta variations of mafic volcanics on the Archean- Proterozoic boundary: Implications for the Nb/Ta imbalance

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Science china Earth Sciences 2005年第8期48卷 1106-1119页

作者： LIU Yongsheng1,2, GAO Shan1,2, WANG Xuance1, HU Shenghong1 & WANG Jianqi2 1. state key laboratory of {3. processes and mineral resources, china university of geosciences, wuhan 4.0074. china 2. key laboratory of Continental Dynamics, Department of Geology, Northwest university, Xi’an 710069, china 1. state key laboratory of {3. processes and mineral resources China University of Geosciences 430074 Wuhan China 2. key laboratory of Continental Dynamics Department of Geology Northwest University 710069 Xi’an China

The HFSE and REE of the Precambrian mafic volcanics from the North china craton demonstrate obvious A(Archean)-P(Proterozoic) boundary. The Neoarchean mafic vol- canics show weak correlation between HFSE and TiO2. Their superchondritic Nb/Ta ratio (18.8±1.2) could be attributed to partial melting of mantle peridotite in the presence of garnet. Compared with Neoarchean mafic volcanics, the Paleoproterozoic ones have higher HFSE contents and lower Nb/Ta ratio (15.6±2.9). The significantly elevated HFSE and REE contents of Paleoproterozoic mafic volcanics imply metasomatic enrichment of mantle source, in which Ti-rich silicates could be present as suggested by significant positive correlations between TiO2 and HFSE. The global database of Precambrian mafic volcanics shows a similar A-P boundary. 23.Archean mafic volcanic suites yield an average Nb/Ta ratio of 17.8±1.9 higher than or close to the PM value; Proterozoic mafic volcanics from 28 suites yield an average Nb/Ta ratio of 14.7±4.1 close to the bulk continental crust (BCC) value (11―17.5). Thus, we suggest that the Nb/Ta deficit could be mainly formed in post-Archean time. Archean mafic volcanics could be one of the geochemical reservoirs complementing the low Nb/Ta of the post-Archean continental crust and DM.

关键词： Precambrian mafic volcanics, Nb/Ta deficit, Archean-Proterozoic boundary.

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