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Continental hydrothermal sedimentary siliceous rock andgenesis of superlarge germanium(Ge)deposit hosted incoal:A study from the Lincang Ge deposit,Yunnan,{2.

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Science china Earth {1. 2004年第11期47卷 973-984页

作者： qi huawen1,2.hu ruizhong1,SU Wenchao1,{2. liang1 & FENG Jiayi1 1.key laboratory of ore deposit geochemistry,chinese academy of sciences,{12. 550002.china 2.Department of Earth sciences,Nanjing University,Nanjing 2.0093,china Correspondence should be addressed to {2. huawen(email: {2.huawen@***) key {1. of {2. deposit geochemistry Chinese Academy of Sciences Guiyang China Department of Earth sciences Nanjing University Nanjing China

There are abundant hydrothermal sedimentary structures and plant fragment fossils in the siliceous rocks from the Lincang Ge deposit. The major element compositions of these siliceous rocks are characterized by high content SiO{1. low TiO{1.and Al{1.3concentrations, and low Al/(Al+Fe+Mn) ratios (0.01. on average). The siliceous rocks are distinctly enriched in Ge, Sb, As, W, and secondly enriched in Cs, U, Mo and Tl. Their total REE content are generally less than 1.g/g, LREE relatively concentrated, and the values of Eu anomaly and Ce anomaly vary from 0.45{1.to 5.1.1.and 0.997 to 1.1.4, respectively. Their NAS-normalized REE patterns are plain or left-inclined. The Oxygen isotope compositions of these siliceous rocks are similar to those of the hydrothermal siliceous sinter. The above characteristics, as well as the geological setting of the deposit, indicate these siliceous rocks formed in continental hydrothermal envi- ronment. As the interlayer or cliff of the Ge-rich coal seams, siliceous rocks tightly contacted with {{1.-body, and the contents of Ge in siliceous rocks vary from 5.6 to 360 μg/g (78 μg/g on aver- age). The Ge content increased in coal which close to the siliceous rocks. With the increase of Ge content, the typical trace element ratios (i.e., Ge/Ga, Nb/Ta and U/Th) and REE patterns of Ge-rich coal are m{{1. close to those of the siliceous rocks. The Ge concentrated in coal seams of the Lincang Ge deposit might be transported by the hydrothermal water, which demonstrated by the siliceous rocks, during the coal-forming processes.

关键词： siliceous rock, continental hydrothermal sedimentation, superlarge Ge deposit, Lincang.

Diagenetic-metallogenic ages of pyritic cherts and their implications in Mojiang nickel-gold deposit in Yunnan Province,{1.

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chinese Science Bulletin 2001年第21期46卷 1823-1827页

作者： FANG Weixuan hu {1. XIE Guiqing SU Wenchao qi liang laboratory of {1. {2. geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550002China Northwest Geological Exploration Bureau Chinese National Nonfer-rous Metal CorporationXi’an 710054China

Diagenetic-metallogenic ages of pyritic cherts formed by the syn-sedimentation of hydrothermal vent and ages of the Jinchang Rock Formation in the Mojiang large nickel-gold deposit in the Ailaoshan gold metallogenic belt have been discussed on the basis of chronology of isotopic {1.. Nickel-gold-bearing pyritic cherts in the mining were formed by syn-sedimentation of hydrothermal vent in the Late Devonian, i.e. age by Sm-Nd isochronal method (t) = (358±8.6) (2.) Ma and age by Rb-Sr isochronal method (t) = (354.7±0.72. (2.) Ma. On the other hand, deep-water cherts from the Jinchang Rock Formation of the Upper Devonian in the area were initiated at the same time; that is, age by Sm-Nd isochronal method (t) = (359(+2.) (2.7) Ma and age by Rb-Sr isochronal method (t) = (358.02.0.30) (2.) Ma.

关键词： metallogenic age age by Sm-Nd isochronal method age by Rb-Sr isochronal method Mojiang nickel-gold deposit.

On emplacement ages of lam-proites in Zhenyuan County,Guizhou Province,china

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chinese Science Bulletin 2002年第10期47卷 874-880页

作者： Weixuan Fang ruizhong {1. Wenchao Su Jiafei Xiao liang {2. Guohao Jiang chinese Acad Sci Inst Geochem Lab Ore Deposit Geochem Guiyang 550002 Peoples R China

Emplacement ages of lamproites that comprise lamproite and olivine lamproite in Zhenyuan County, Guizhou Province, china, have been constrained by the whole-rock Sm-Nd and Rb-Sr isochron methods and the whole rock K-Ar method. Intrusive activities of lamproites in the Sinantang area of Zhenyuan County, Guizhou Province, took place during the Late Cambrian, as indicated by the Sm-Nd isochron ages (t) = (503±1.) ({1.) Ma and by the Rb-Sr isochron ages (t) = (501.{1.4.6) ({1.) Ma. Intrusive activities of olivine lamproites at the Maping with Ⅱ -type diamond and Xitou in Zhenyuan County, Guizhou Province, took place from the Late Cambrian to the Early Ordovician, as evidenced by the Sm-Nd isochron ages (t) = (50{1.{1.) ({1.) Ma and by the Rb-Sr isochron age (t) = (50{1. {1.) ({1.) Ma. This suggests that the upwelling hot materials derived from the deep mantle were emplaced from the Late Cambrian to the Early Ordovician (503-497 Ma), while the time terminal of cooling of the geothermal event of

关键词： the Sm-Nd isochron age the Rb-Sr isochron age whole rock K-Ar method lamproite Zhenyuan County of Guizhou Prov-ince china.

Characteristics of rare-earth elements (REE),strontium and neodymium isotopes in hydrothermal fluorites from the Bailashui tin {1. in the Furong ore field,southern hunan Province,{2.

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chinese Journal Of {1. 2008年第4期27卷 342-350页

作者： YUAN Shunda PENG Jiantang hu ruizhong BI Xianwu qi {2. LI Zhaoli LI Xiaomin ShuANG Yan State key {1. of {2. deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Cruiyang 550002 China Graduate School Chinese Academy of Sciences Beijing 100049 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

In this paper the authors present the REE concentrations and Sr and Nd isotopic compositions of fluorites from the Bailashui tin {1. of the Furong ore field,southern hunan Province. The results showed that the total amount of REE in fluorites is usually low,ranging from 0.705 to 8.785 μg/g with the chondrite-normalized REE dis-tribution patterns similar to those of the {2.tianling granites in the study area,characterized by LREE-enrichment patterns with pronounced negative Eu anomalies. The fluorites vary in Sr isotopic composition within the range of 0.7083-0.7091.the values are lower than those of the granites and higher than those of the host carbonate rocks in this area. The εNd(t) values of fluorites vary between -9.4 and +1..3,revealing that both the crust-and mantle-source materials were involved in the ore-forming hydrothermal fluids. Combined with previous studies on this ore {1.,the Bailashui tin {1. is temporally and spatially closely related with granitic magmatism in this area. The hydro-thermal fluorites are the product of fluid/rock interactions between granitic magmatic hydrothermal fluid and marine carbonate rocks. The REE and F in the ore-forming fluid were derived from the granites,whereas Sr in the ore-forming fluid came mainly from the granitic magmatic hydrothermal fluid and marine carbonate rocks,although variations in Sr isotopic composition cannot be explained by a simple mixture of these two end-members. Evidence demonstrated that the ore-forming fluids are of crustal-mantle mixing origin,but that the fluids were probably in-completely homogenized and this may be caused by inhomogeneous mixing of the fluids of different sources.

关键词：萤石同位素锡沉淀稀有地球元素