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Study on lithogeochemistry of Middle Jurassic basalts from southern China represented by the Fankeng basalts from Yongding of Fujian Province

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Science China Earth Sciences 2006年第10期49卷 1020-1031页

作者： ZHOU Jincheng1,2. JIANG Shaoyong1,2. WANG Xiaolei1,2. YANG Jinghong 1,2.& ZHANG Mengqun 3 1. state key {2. of {2. Deposit research, nanjing university, nanjing 2.0093, China 2. Department of Earth Sciences, nanjing university, nanjing 2.0093, China 3. Modern Analysis Center, nanjing university, nanjing 2.0093, China 1. state key {2. of {2. Deposit research Nanjing University Nanjing 210093 China 2. Department of Earth Sciences Nanjing University Nanjing 210093 China 3. Modern Analysis Center Nanjing University Nanjing 210093 China

There exists an E-W trending Middle Jurassic volcanic zone in southern China. The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example. The Fankeng basalts have TiO2.contents in the range of 1.92.-3.2.%. They are classified as high-Ti basalts. They also have higher total Fe (averaging FeO* = 11.09%). The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cre- taceous basalts from southeastern coast of China. They have higher HFSE, such as Th, Nb, Ta, Zr and Ti. Their element ratios related with HFSE, such as Zr/Ba, La/Nb, La/Ta ,Zr/Y, Ti/Y, Ba/Nb, K/Ti and Rb/Zr are similar to those of OIB. The most samples have ε Nd(T) of-0.70-0.2., which are near chondrite. Some samples have higher ε Nd(T) of ***, these basaltic magmas might be derived from depleted asthenospheric mantle. The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time. The (Early-) Middle Jurassic basalts and gabbros from southeastern Hunan, southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian. Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time. Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.

关键词： interaction between asthenosphere and lithosphere, lithogeochemistry, basalts, Middle Jurassic, southern China.

Mid-low temperature metallogenic province of South China: A continental-scale mineralization and temperature zoning

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Chinese Science Bulletin 1999年第S2期44卷 27-29页

作者： MA Dongsheng state key {2. for {2. of mineral deposits, nanjing university nanjing 2.0093, China state key {2. for {2. of mineral deposits Nanjing University Nanjing 210093 China

CHARACTERIZED by Au,Sb and Hg mineralization, the mid-low temperature metallogenic province in SouthChina is composed of the Au-Sb belt in the Proterozoic group on the Jiangnan Old Land, and the Hunan-Guizhou Hg belt in the Cambrian system, the SW China Carlin-type Au belt in the Permian andTriassic, and the Mid-Hunan Sb belt in the Devonian. The latter three are located in the basins respectively on the NW,SW and SE of the Jiangnan Old Land. The province holds nearly 50% Sb ore reserves and supplies about 70% annual antimony mine production in the world, and about 80% both ofexplored reserves and annual output of Hg in China. In the last twenty years, discovery of the micrograined dissemination Au deposits in the SW China Au belt made an important breakthrough in

关键词： South China continental-scale mineralization ore-forming temperature zoning.

Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

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Science China Earth Sciences 2006年第8期49卷 862-871页

作者： YANG Ruiyan1,2. MA Dongsheng2. BAO Zhengyu3, PAN Jiayong2. CAO Shuanglin2.& XIA Fei2.1. School of Mathematics and Physics, China university of Geosciences, Wuhan 430074, China 2. state key laboratory for research of mineral deposits,{2., nanjing 2.0093, China 3. Faculty of Earth Sciences, China university of Geosciences, Wuhan 430074, China 1. School of Mathematics and Physics China University of Geosciences Wuhan 430074 China 2. state key laboratory for research of mineral deposits Nanjing University Nanjing 210093 China 3. Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2.0.4 m/a.

关键词： ore-forming fluid, numerical simulation, geothermal field, geofluid transport, Xikuangshan, antimony deposits.

Water in peridotite xenoliths from South China

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Science China Earth Sciences 2011年第10期54卷 1511-1522页

作者： WANG Rong 1,2.3 & ZHANG BaoMin 3 1 Faculty of Land Resource Engineering, Kunming university of Science and Technology, Kunming 650093, China 2.state {2. {2. for mineral deposits research, nanjing university, nanjing 2.0093, China 3 Faculty of Earth Science, China university of Geosciences, Wuhan 430074, China 1. Faculty of Land Resource Engineering Kunming University of Science and Technology Kunming 650093 China2. State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing 210093 China3. Faculty of Earth Science China University of Geosciences Wuhan 430074 China

The water contents of nominally anhydrous clinopyroxene （cpx）, orthopyroxene （opx） and olivine （ol） in peridotite xenoliths hosted by Cenozoic basalts from Yingfengling, Zhangchouchun, Fujitian and Lindi, South China, were measured by Micro- FTIR. All cpx and opx grains contained a certain amount of water, which was indicated by the presence of hydroxyls in the crystal structure. The water contents （H2., ppm） of cpx and opx from peridotite xenoliths of the study areas were 2.3-981, 183-752. 73-586 and 51-42. ppm, and 82.471, 74-571, 53-170 and 9-135 ppm, respectively. No prominent OH absorption bands were detected for any ol grains, indicating that the water contents were below the detection limit （approximately 2.ppm）. The entire rock contents recalculated according to mineral volume proportions were 49-163, 48-168, 2.-111 and 8-40 ppm, respectively. Combined with previously reported data describing the water contents of peridotite xenoliths worldwide, the results presented here suggest that water distribution in the continental lithospheric mantle is spatially heterogeneous at a global scale. The lithospheric mantle of South China is much richer in water than that of the North China Craton, and is close to that typical of off-craton localities, such as the Basin and Range Province, and Massif Central.

关键词： FTIR water peridotite xenoliths South China

Observation of ultra-microtexture of fault rocks in shearing-sliding zones

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Progress in Natural Science:Materials International 2005年第5期15卷 430-434页

作者： SUN Yan1*, LU Xiancai1, SHU Liangshu1, GU Lianxing1, ZHU Wenbin1, GUO Jichun1 and LIN Aiming2.1. state key {2. of {2. deposits research, Department of Earth Sciences, nanjing university, nanjing 2.0093, China 2. Department of Geosciences, Shizuoka university, Shizuoka 836, Japan) state key {2. of {2. deposits research Department of Earth Sciences Nanjing University Nanjing 210093 China Department of Geosciences Shizuoka University Shizuoka 836 Japan

Based on scanning electronic microscopic observation of three fault rocks in ductile-brittle shearing-sliding zones (including one palimpsest mylonite sampled from deep bore cores of Cajon Pass, California, two flowing-structured carbargillites sampled from Shaancan Well 1 located in north Shaanxi, and Well NH located in Huanghai, respectively), micron- and nanometer-scaled ultra-fine grinding grain texture of fault rocks is discovered in this study. And the geological significance of grinding grain texture is discussed in terms of its particulate organization, rheology of particulate slipping, laminar petrography and micro dynamics including dynamothermal metamorphism, fluid transferring, particulate autorotation, and so on. In addition, the remaining problems to be solved and broad prospects in this new study field are also discussed.

关键词： ductile-brittle shearing zone fault rock texture of grinding grain rheology of particulate slipping.

Transition from platemargin to intraplate environment: Geochemistry of basalts in Paleogene Liaohe basin, northeastern China

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Science China Earth Sciences 2005年第12期48卷 2069-2080页

作者： WU Changzhi1, GU Lianxing1, REN Zuowei1,2. ZHANG Zunzhong1, CHEN Zhenyan2.& ZHAO Ming1 1. state key {2. of {2. Deposit research (nanjing university), Department of Earth Sciences, nanjing university, nanjing 2.0093, China 2. Exploration and Development research Institute of Liaohe Oilfield Branch Company, PetroChina, Panjin 12.010, China 1. state key {2. of {2. Deposit research (nanjing university) Department of Earth Sciences Nanjing University 210093 Nanjing China 2. Exploration and Development research Institute of Liaohe Oilfield Branch Company PetroChina 124010 Panjin China

Paleogene basalts from the Liaohe basin, northeastern China, are dominated by alkaline olivine basalts and olivine basalts. These basalts are generally enriched in high field strength elements (HFSE), depleted in large ion lithophile elements (LILE) and comparable to those of typical ocean island basalts (OIB). Positive anomalies of Ba, Sr and Zr with high Nb/U, U/Pb, Ce/Pb and Zr/Hf ratios imply that materials from an oceanic crust had been added to the mantle sources of the basalts. In addition, the basalts are generally depleted in Sr, Nd and Pb isotopes, indicating that an enriched mantle (EMI) and a depleted mantle (DM) sources were added to the OIB-like resource. Comprehensive research on lithosphere evolution and tectonic setting of the Liaohe basin and surrounding areas suggests that these basalts were derived by variable degrees of partial melt-ing from an upwelling asthenosphere mantle. Materials from an oceanic lithosphere were added to the source in company with Paleogene tectonic transition from platemargin to intraplate envi-ronment. Retreating and steepening of the subducting Pacific oceanic plate could be the main cause for the tectonic environment transition.

关键词： geochemistry, basalt, Paleogene, Liaohe basin, North China Block, eastern China.

Evolution of chlorite composition in the Paleogene prototype basin of Jiyang Depression, Shandong, China, and its implication for paleogeothermal gradient

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Science China Earth Sciences 2007年第11期50卷 1645-1654页

作者： ZHAO Ming1, CHEN XiaoMing1, JI JunFeng1, ZHANG Zhe1 & ZHANG Yun2.1 state key {2. for {2. deposits research, Department of Earth Sciences, nanjing university, nanjing 2.0093, China 2.Jiangsu Survey Institute of Engineering and Physics, nanjing 2.0008, China 1. state key {2. for {2. deposits research Department of Earth Sciences Nanjing University Nanjing 210093 China 2. Jiangsu Survey Institute of Engineering and Physics Nanjing 210008 China

The Dongying Basin, Huimin Basin, and Zhanhua Basin constitute the Jiyang Depression in Shandong Province. They are major oil and gas exploring districts within the depression. Through reconstructions of the paleotemperature of the three basins facilitated with the chlorite geothermometry, the thermal history of the Paleogene prototype basin in Jiyang Depression and its geologic significance were explored. This study reveals that the Si^(4+) component in chlorites reduces gradually as its buried depth increases, while the AI~Ⅳ component increases accordingly. The chlorite type changes from silicon-rich diabantite to silicon-poor ferroamesite and prochlorite. The prochlorite in this district only appears in the deep buried depth, high temperature, and relatively old stratigraphies; while the diabantite appears in the shallower buried, low temperature, and newly formed strata; the ferroamesite exists in the conditions between prochlorite and diabantite formation. The diagenetic temperatures of the chlorites in these Paleogene basins are 171 — 2.8℃ for the Dongying Basin, 160—2.2. for the Huimin Basin, and 135—180℃ for the Zhanhua Basin. The differences of the chlorite diagenetic temperatures in the three basins were controlled by the duration time of the structural depressing processes. Higher temperature indicates longer depression time. The relationship between the chlorite diagenetic temperature and its buried depth indicates that the average paleogeothermal gradient is about 38.3℃ /km in the Paleogene prototype basin of Jiyang Depression. It was higher than the present geothermal gradient (2.—30℃/km). This phenomenon was attributed to the evolution of the structural dynamics in the depression basin.

关键词： Paleogene,Jiyang depression,chlorite component,chlorite geothermometry,paleotemperature,paleogeothermal gradient

Rb-Sr isochron ages and significance of bimodal volcanic association in Baimianshi uranium ore-field, South China

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Chinese Science Bulletin 1999年第S2期44卷 3-4页

作者： CHEN Peirong~1, WANG Yinxi~2. NI Qisheng~1, KONG Xinggong~2.and ZHANG Bangtong~2.1. state key {2. of {2. deposits, Department of Earth Sciences, nanjing university, nanjing 2.0093, China 2. Center of Modern Analysis, nanjing university, nanjing 2.0093, China state key {2. of {2. deposits Department of Earth Sciences Nanjing University Nanjing 210093 China Center of Modern Analysis Nanjing University Nanjing 210093 China

1 Geologic background THE volcanic U-deposits are generally associated with felsic to intermediate volcanic rock and their sedimentary derivatives. However, uranium mineralization has been found to be spatially associated with thebasalt of bimodal volcanic associations in Baimianshi uranium ore field. Baimianshi uranium ore-field islocated in Baimianshi volcanic-sedimentary basin of south Jiangxi Province. The cover rocks of the basinconsist of a suite of bimodal volcanic-sedimentary sequences. Its basement rocks are two-mica granites ofBaimianshi rock body. The basalt of cover rocks is interbedded with arkoses in lower sequence, and rhyolite or rhyolitic tuff in upper sequence. Uranium minerals mainly occur as disseminations in the

关键词： Rb-Sr isochron ages bimodal volcanic rocks uranium ore-field south China.

The history of crustal uplift and metamorphic evolution of Panzhihua-Xichang micro-palaeoland, SW China:Constraints on Sm-Nd, ^(40)Ar/^(39)Ar and FT ages of granulites

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Science China Earth Sciences 2004年第8期47卷 689-703页

作者： XU Shijin1, LIU Wenzhong1, WANG Rucheng1, YU Hangbo1, LI Daming2. WAN Jinglin2.& FANG Zhong1 1. Department of Earth Sciences and state key {2. for {2. deposits research, nanjing university, nanjing 2.0093, China 2. Institute of Geology, China Seismological Bureau, Beijing 10002., China 1. Department of Earth Sciences and state key {2. for {2. deposits research Nanjing University 210093 Nanjing China 2. Institute of Geology China Seismological Bureau 100029 Beijing China

Panzhihua-Xichang (Panxi) micro-palaeoland is the oldest terrane on the western margin of the Yangtze Block. Some intermediate-basic granulites are considered to be the crys-talline basement of lower crust in the terrane. Granulite-facies metamorphism of the granulites was developed in the period from 1186 Ma to 112. Ma. The origin of granulites was related to the collision orogenic process occurring when the micro-palaeolands merged to form the Rodinia Supercontinent. Amphibolite-facies retrogressive metamorphism of granulites took place in the period from 877 Ma to 82. Ma. This period was consistent with the breakup time of the Rodinia Supercontinent. 40Ar/39Ar ages and fission track (FT) ages of granulites in the Panxi mi-cro-palaeoland show that the vertical movement history of crustal rocks was a slow uplift process of the rigid terrane in the time from Neoproterozoic to Mesozoic. The subduction of India Plate towards Euroasia Plate resulted in the rapid uplift of the Qinghai-Tibetan Block in Cenozoic. Meanwhile, the Qinghai-Tibetan Block moved towards east. Consequently the Panxi terrane was uplifted rapidly. As a result of the collision orogeny between the Qinghai-Tibetan Block and the Panxi terrane, the granulite-facies crystalline basement in this region was exhumed and exposed to the surface.

关键词： granulite,isotope geochronology,crustal uplift movement,Panzhihua-Xichang region,western margin of Yangtze Block.