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New stylophorans(Echinodermata) from the Upper Cambrian of Guangxi,South china

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Science china earth sciences 2008年第2期51卷 181-186页

作者： HAN NaiRen1 & CHEN GuiYing1,2 1 Department of Resources and Environmental Engineering, Guilin university of Technology, Gulin 541004, china 2 faculty of earth sciences, china university of Geoscience, wuhan 4.0074. china Department of Resources and Environmental Engineering Guilin University of Technology Gulin China faculty of earth sciences China University of Geoscience Wuhan China

This paper describes for the first time the cornute stylophorans (Echinodermata) in china. The new material came from the Guole Formation of the Furongian (Late Cambrian) in the Guole area of Jingxi, Guangxi Province, South china. These new cornute specimens are preserved in situ and found along with well-preserved trilobites and brachiopods. One new species, Phyllocystis jingxiensis sp. nov., is proposed to accommodate these unusual materials. The new species is defined by the small, heart-shaped theca with the frame composed of ten narrow, smooth and thick marginal plates, three adoral plates and distinctive zygal and aulacophore. Both supracentrals and infracentrals are polygonal-outlined. The marginal plate M1' on the inferior face extends posteriorly to form zygal that possesses a broadened proximal end and the proximal portion joining with the conjunction between M4 and M5 on the inferior face. Aulacophore comprises ten segments at its proximal part and is conical at the middle part (named stylocone). Its distal portion is rather long and bears conspicuous ambulacrum grooves. Tectals are horizontally arranged on superior face and obliquely arranged on inferior face. Both cothurnopore and anal pyramid are vaguely seen on the right anterior corner and the extremity of theca's superior face.

关键词： Phyllocystis Stylophora Echinodermata Cambrian Guangxi South china

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 4.0074. 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 4.0074. china School of Mathematics and Physics China University of Geosciences Wuhan China State Key Laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China faculty of earth sciences China University of Geosciences Wuhan 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.

Anatexis in Himalayan crust:Evidence from geochemical and chronological investigations of Higher Himalayan Crystallines

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Science china earth sciences 2005年第9期48卷 1347-1356页

作者： YANG Xiaosong1, JIN Zhenmin2 & MA Jin1 1. State Key Laboratory of earthquake Dynamics, Institute of Geology, china earthquake Administration, Beijing 100029, china 2. faculty of earth sciences, china university of geosciences, wuhan 4.0074. china State Key Laboratory of earthquake Dynamics Institute of Geology China Earthquake Administration Beijing China faculty of earth sciences China University of Geosciences Wuhan China

Migmatization in Higher Himalayan Crystallines (HHC) results from anatexis. The widely distributed migmatites in HHC are an important clue to investigate the relationship be- tween anatexis and the origins of Higher Himalayan leucogranites (HHL), and to understand the effect of anatexis on crustal evolution during the post-collision period. We studied in detail the chemical features of three basic constituent parts of the migmatites, i.e. leucosome, mesosome and melanosome, and determined the K-Ar ages of leucosomes. Our studies indicate that type-I leucosome is the product of crystallization of melt generated by partial melting of mesosome at source region, but type-II leucosome and HHL probably underwent crystallization differentiation of plagioclase during melt aggregation and migration. The age of 22.67 Ma of Type-I leucosome, which is a little older than the beginning of MCT movement, indicates that anatexis may have played an important role in the formation of MCT. That the ages of type-II leucosome (ranging from 14.82 to 18.37 Ma) are consistent with that of HHL provides new chronological evidence for the relationship between migmatization and HHL. We obtained a very young age of 6.23 Ma of Type-II leucosome that provides new time constraint on magma activity in the central segment of Higher Himalayas.

关键词： Higher Himalayan Crystallines, migmatite, anatexis, leucosome, K-Ar age.

Experimental study of ore gabbro liquid immiscibility

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Science china earth sciences 2005年第4期48卷 496-505页

作者： SANG Zunan1,2, XIA Bin1, ZHOU Yongsheng3 & JIN Zhenmin4 1. Guangzhou Institute of Geochemistry, Chinese Academy of sciences, Guangzhou 510640, china 2. wuhan university, wuhan 430072, china 3. Institute of Geology, china Seismological Bureau, Beijing 100029, china 4. faculty of earth sciences, china university of geosciences, wuhan 4.0074. china Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China wuhan university Wuhan China Institute of Geology China Seismological Bureau Beijing China faculty of earth sciences China University of Geosciences Wuhan China

In this paper, the authors present the results of a preliminary experimental study on partial melting of fine-grained gabbro, Panzhihua, Sichuan Province, china. Experiments were conducted under (confining) pressure ranging from 450 to 500 MPa and temperature of 900— 1200℃. The results show that the initial melt is distributed along grain boundaries and triple junctions. Liquid immiscibility phenomena are noted in the melt with two compositional different melt phases, i.e. matrix and sphere phases. The matrix phase is relatively rich in Si, Al and K, and is depleted in Mg, Fe, Ca, Na and Ti, whereas the sphere phase shows opposite trends. The calculation of the melt free energy indicates that the liquid immiscibility is governed by the rule of thermodynamics, as the liquid immiscibility would result in the decrease in free energy of the melt system. The field relationships suggest that the liquid immiscibility may have played an important role in the generation of ore magma of Panzhihua V-Ti magnetite ore deposit. This study thus provides experimental constraints on the mechanism of the formation of V-Ti magnetite deposite.

关键词： partial melting, experimental study, gabbro, liquid immiscibility, ore formation mechanism.

Zircon geochronology and geochemistry of mafic xenoliths from Liaoning kimberlites:Track the early evolution of the lower crust,North china Craton

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Science china earth sciences 2004年第11期47卷 961-972页

作者： ZHENG Jianping1,YU Chunmei1,LU Fengxiang1 & LI Huimin2 1.faculty of earth sciences,china university of geosciences,wuhan 4.0074.china 2.Tianjin Institute of Geology and Mineral Resources,Tianjin 300170,china faculty of earth sciences China University of Geosciences Wuhan China Tianjin Institute of Geology and Mineral Resources Tianjin China

Mafic xenoliths from Paleozoic Fuxian kimberlites (Liaoning Province) mainly in- clude garnet granulite, with minor pyroxene amphibolite, meta-gabbro and pyroxene syenite. The SiO2 contents of the xenoliths are from 47.3 wt% to 49.9 wt%. The granulites are mainly coarse-medium grained and reasonably with well-developed granoblastic (mostly polygonal) texture, contain the assemblage of garnet + plagioclase + pyroxene + K-feldspar ±phlogopite. The mineral assemblage of the amphibolites is plagioclase + pyroxene + amphibole ±K-feldspar, with the equilibrium temperature and pressure conditions of 744—821℃ and 0.76—0.88 GPa. The granulites are regarded as derivation from the lower crust depth (more than 29 km), below the amphibolites. Garnet granulites compositionally correspond to sub-alkalic basalt, and have wide ranges of Ni abundance (133—840 ppm), and Nb/Y (0.12—1.85), Nb/U (3.51—53.86) and Ta/U (0.38—2.48). The amphibolite and the syenite correspond to alkalic basalt. The Fuxian ma- fic xenoliths are regarded as the metamorphic product of the underplated magmas (including fractional crystallization or not) experienced the contamination with the pre-existed crustal com- ponents, and partly effected by kimberlitic magmas. The concordant ages of zircons for the gab- bro (2610—2580 Ma) and the near-concordant upper intercept ages of zircons for the garnet granulite and pyroxene amphibolite (2578—2538 Ma) indicate that they are currently known as the oldest deep-seated xenoliths from the lower crust of the North china Craton. These ages recorded the formation of the united Eastern Block of the North china Craton, That is, Neoar- chean (2.6—2.5 Ga) is an important continental crustal growth period of the North china Craton. The lower intercept age of the garnet granulite (1853 Ma) recorded an important tectonic thermal event in Paleoproterozoic. This event was probably related to collision of the East and West block, and resulted in the final assembly of the North china

关键词： mafic xenolith, petrochemistry, zircon geochronology, petrogenesis, lower crustal evolution, North china Craton.

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,wuhan 4.0074.china 2State Key Laboratory of Geological Processes and Mineral Resources,china university of geosciences,wuhan 4.0074.china 3 Graduate School,china university of geosciences,wuhan 4.0074.china 4 Biogeological and Environmental Geology Laboratory of Ministry of Education(china university of geosciences) ,wuhan 4.0074.china 5 Sino-Hungary Joint Laboratory of Environmental sciences and Health,china university of geosciences,wuhan 4.0074.china faculty of earth Science China University of Geosciences Wuhan China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan China Graduate School China University of Geosciences Wuhan China Biogeological and Environmental Geology Laboratory of Ministry of Education (china university of geosciences) Wuhan China Sino-Hungary Joint Laboratory of Environmental sciences and Health China University of Geosciences Wuhan 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 showδ53Cr 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'sδ53Cr 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

Depositional Model and Tectonic Evolution of Tertiary Transform-Extensional Basins in Northeast china: Case Study on Yitong and Damintun Grabens

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Journal of earth Science 1997年第1期16卷 62-67页

作者：  Xie Xinong Huang Yanqiu faculty of earth Resources, china university of geosciences, wuhan 4.0074.Lu Zongshengfaculty of earth sciences, china university of geosciences, wuhan 4.0074.

? The formation and evolution of the Tertiary transformextensional basins in Northeast china are controlled by extensional and strikeslidding combinational processes because the giant strikeslip fault system, TanchengLujiang fault, cut through the basement or margin. Two kinds of structural styles have been identified in Northeast china: Yitong and Damintun styles. The former shows a clear asymmetry, in which sediments came mainly from two lateral sides and thick filling sediments were adjacent to the main strikeslip fault. The latter shows symmetry filling, in which sediments came from the long axial ends in addition to from two lateral sides. The tectonic evolution of Tertiary transformextensional basins in Northeast china underwent three stages: Eocene extensional, Oligocene transformextensional and Neogene transpressional stages.

关键词： transformextensional basin Tertiary Yitong graben Xialiaohe basin.

^(40)Ar-^(39)Ar and U-Pb ages of metadiorite from the East Kunlun Orogenic Belt: Evidence for Early-Paleozoic magmatic zone and excess argon in amphibole minerals

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Chinese Science Bulletin 2001年第4期46卷 330-333页

作者： CHEN Nengsong, SUN Min, ZHANG Kexin & ZHU Yunhaifaculty of earth sciences, china university of geosciences, wuhan 4.0074. china Department of earth sciences, The university of Hong Kong, Hong Kong SAR, china faculty of earth sciences China University of Geosciences Wuhan China Department of earth sciences The University of Hong Kong Hong Kong SAR China

Single-grain zircon U-Pb and amphibole 40Ar-39Ar dating have been conducted on a deformed and metamorphosed diorite in the East Kunlun Orogenic Belt, which intruded into the middle Proterozoic Kuhai Group exposed in the south of Xiangride region, Dulan County, NW Qinghai Province. The zircon gives a concordant U-Pb age of (446.5±9.1) Ma. The amphibole yields Ar plateau age of (488.0±1.2) Ma and an isochronal age of (488.9±5.6) Ma. Age results of both stepwise released Ar and conventional K-Ar analysis are remarkably higher than that of zircon U-Pb, suggesting that the amphibole contains excess argon and the amphibole plateau age cannot be taken as the timing of metamorphism or deformation. The zircon age is interpreted to be crystallization age of the diorite pluton, which suggests that an Early-Paleozoic magmatic zone indeed existed in the East Kunlun Orogenic Belt stretching along the region south to the Golmud, Normuhong and Xiangride.

关键词： East Kunlun Orogenic Belt metadiorite geochronology excess argon.

Sedimentary geochemistry of the Cambrian-Ordovician cherts: Implication on archipelagic ocean of North Qilian orogenic belt

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Science china earth sciences 2007年第11期50卷 1628-1644页

作者： DU YuanSheng1,2, ZHU Jie1, GU SongZhu1, 2, XU YaJun1 & YANG JiangHai1 1 faculty of earth sciences, china university of geosciences, wuhan 4.0074. china 2 Key Laboratory of Biogeology and Environment Geology of Education Ministry, wuhan 4.0074. china faculty of earth sciences China University of Geosciences Wuhan China Key Laboratory of Biogeology and Environment Geology of Education Ministry Wuhan China

The Caledonian North Qilian orogenic belt lies between the North china plate and the Qaidam mi-croplates, and resulted from the collision among the Qaidam microplate, mid-Qilian block and the North china plate. The orogen initiated from the rifting of the Late Proterozoic Rodinia, and then it experi-enced stages of Cambrian rift basin and Ordovician archipelagic oceanic basin, and foreland basin during Silurian to Early-Middle Devonian. The average ratios of Al/(Al+Fe+Mn), Al/(Al+Fe), δ Ce, Lan/Ybn and Lan/Cen from cherts of Cambrian Heicigou Formation are 0.797, 0.627, 1.114, 0.994 and 1.034 re-spectively. In the NAS standardized REE distribution pattern, the cherts from Xiangqianshan is slightly HREE enriched, and the cherts from Ganluci and Shiqingdong are plane. All of these features indicated that Cambrian cherts of the Heicigou Formation originated from a continental margin rift background. On the contrary, the average ratios of Al/(Al+Fe+Mn), Al/(Al+Fe), δ Ce, Lan/Ybn, Lan/Cen of the Ordovician chert from Dakecha, Cuijiadun, Shihuigou, Laohushan, Heicigou, Maomaoshan, Bianmagou, Da-chadaban, Baiquanmen, Jiugequan and Angzanggou, are respectively 0.72, 0.58, 0.99, 1.09 and 0.96 respectively. Their NAS standardized REE distribution patterns of most Ordovician cherts are plane mode or slightly HREE enriched. The REE distribution pattern of few samples of cherts are slightly LREE enriched. Characteristics of sedimentary geochemistry and tectonic evolution demonstrated that the Cambrian-Ordovician cherts, associated with rift, oceanic, island arc and back-arc volcanic rocks, was not formed in a typical abyssal oceanic basin or mid-oceanic ridge. On the contrary, they formed in a deepwater basin of continental margin or a archipelagic ocean tectonic setting. Several Early Paleo-zoic ophiolite belts in North Qilian and adjacent periphery Qaidam microplate imply that an archipelagic ocean during Ordovician existed in the east of Pro-Tethys.

关键词： North Qilian orogenic belt,Cambrian-Ordovician,cherts sedimentary geochemistry,archipelagic ocean