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Essential natures of Carlin-type gold mineralization in the Zhenxun Basin

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chinese Science Bulletin 1999年第S2期44卷 238-240页

作者： MA Jianqin~1 and ZHANG Fuxin~2.1. institute of geochemistry, {2. Academy of Science,{3. Present address: Highway Egineer College, Xi’an Highway University, Xi’an 710064. {4. 2. Department of Geology, Northwest University, Xi’an, 710069, {4. institute of geochemistry Chinese Academy of Science Guiyang 550002 China Highway Egineer College Xi' an Highway University Xi' an 710064 China Department of Geology Northwest University Xi' an 710069 China

THE Zhen’ an-Xunyang (Zhen-Xun) Basin, located in the center of the Qinling Minor Plate in the Qinling orogen, develped and evoluted from the Devonian to the Triassic. The basin and its basement aresimilar to that of the southwestern part of the Yangtze Plate, where occur rich epithermal deposits. Thebasement of the basin is composed of the Proterozoic low-grade metamorphised volcanic and sedimentaryrocks, on which weakly metamorphised sedimentary and sedimentary rocks are deposited from the Cambrian to the Triassic. There occur three kinds of epithermal metal deposits: exhative-sedimentary-reformationtype Pb-Zn deposit (such as Xitonggou and Yuexi) ; reformation type Hg-Sb deposit (such as Dingjiashanand Shijiashan) ; sedimentary-reformation type Au deposit (such as Jinlongshan, Qiuling, Yaojie andJiashigou). The Au deposits are associated with minor Sb deposit. This contribution demonstrates onlythe essential natures of the epithermal gold mineralization.

关键词： Carlin type gold mineralization Zhenxun Basin.

Determination of disperse elements in black shale by inductively coupled plasma mass spectrometry

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chinese Science Bulletin 1999年第S2期44卷 173-174页

作者： QI Liang, HU Jing and DENG Hailing institute of geochemistry Ore Deposit Open Laboratory, {2. Academy of Sciences,{3. institute of geochemistry Ore Deposit Open Laboratory Chinese Academy of Sciences Guiyang 550002 China

THE elements Se, Te, Ge, Re are easily evaporated out when HClO4. HNO3. HF are used as the opendigestion method. There is a great amount of organic and inorganic carbon in black shale, so it is necessary to use oxide ... 详细信息

THE elements Se, Te, Ge, Re are easily evaporated out when HClO4./sub>, HNO3./sub>, HF are used as the opendigestion method. There is a great amount of organic and inorganic carbon in black shale, so it is necessary to use oxide acid （HClO4./sub>, HNO3./sub>） to digest the samples, and the Cl will interfere the determinationof Se and Ge. In this note we reported a simple digestion method for black shale. The sample was digested with HNO3./sub> and HF in PTFE pressure bomb at 190 for 3.h, the rest HF was reacted with HBO, toprotect the introduction system of ICP-MS. After digestion, the samples were determined directly by ICP-MS. So the recoveries were better than the open digestion method. For 50 mg sample,1.5 mL HNO3./sub> and4.drops of HF can completely dissolve black shale. Inductively coupled plasma mass spectrometry has been successfully used for determination of As,Se, Te, Bi in geological materials. In geological and biological samples, the concentrations of ele-

关键词： disperse elements black shale ICP-MS.

Effect of low-temperature mineralization of mantle fluid processes: as exemplified by the polymetallic deposits of Cenozoic alkali-rich porphyry of western Yunnan, china

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chinese Science Bulletin 1999年第S2期44卷 24-25页

作者： LIU Xianfan~(1,2., GAO Zhenmin~1, LIU Jiajun~1, ZHAN Xinzhi~1, LI Chaoyang~1 and SU Wenchao 1. institute of geochemistry, {2. Academy of Sciences,{3. 2. Chengdu institute of Technology, Chengdu 610059, china institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China Chengdu institute of Technology Chengdu 610059 China

SANJING region (the region of three rivers, i.e. Jinsha-Lanchang-Nujiang rivers) is a very active Cenozoicinterplate deformation area on the east margin of Qinghai-Xizang Plateau, where the alkali-rich porphyrybodies occur extensively and the porphyry-related polymetallic mineral resources are produced. Manystudies on the petrology and geochemistry of the alkali-rich porphyry have been carried out and thegenerally accepted conclusion is that the petrogenesis material source has something to do with the enriched source in the mantle. The integrated interactive factors of the mineralization related to the alkalirich porphyry consist in the favourable combination of the mantle fluid metasomatism, which is derivedfrom the deep processes, and the conducting and controlling roles of the large-scale deep faults. Alongwith the changes in physical and chemical conditions caused by the diffusion of the ore-forming

关键词： low-temperature mineralization mantle fluid processes alkali-rich porphyry deposit Cenozoic Yunnan.

Palaeoclimatic cycles and new glacial periods induced by the impact of extraterrestrial bodies

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chinese Science Bulletin 1999年第S2期44卷 128-130页

作者： WANG Shijie, OUYANG Ziyuan, XIAO Zhifeng and LI Chunlai State Key Laboratory of Environmental geochemistry, institute of geochemistry, {3. Academy of Sciences,{4.. State Key Laboratory of Environmental geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE consequence of "nuclear winter" induced by nuclear war and climatic catastrophe induced by extraterrestrial impact were widely studied for fear of the potential danger of the basic nuclear war (the totalexplosive equivalent 5 000Mt TNT). Using zero-dimensional energy balance model authors reportedthe short-term climatic effect induced by six huge Cenozoic bolide-impact events (65, 3., 15, 2.4.1.1, 0.73.MaBP). However, only the direct climatic effect of dusts yielded by the impact was considered in the previous study. In this note, based on the previous simulation results the effect of variance ofglobal reflectance with temperature on the long-term climatic change was further taken into *** with the strata records of palaeoclimatic change the relationship of impact energy with its in-

关键词： bolide impact events palaeoclimatic cycle formation of new glacial period simulating calculation Cenozoic.

The continental hydrothermal sedimentary origin of the Dashui superlarge gold deposit in Gansu Province, china

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chinese Science Bulletin 1999年第S2期44卷 210-212页

作者： LI Hongyang~1, YANG Zhusen~1, GAO Zhenmin~1, LUO Taiyi~1, DING Zhenju~1 and YAN Shenghao~2.1. institute of geochemistry, {2. Academy of Sciences,{3. 2. institute of Mineral Deposits, {2. Academy of Geological Sciences, Beijing 10003., china institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing 100037 China

THE Dashui gold mine, situated in Gansu Province of western china, is a superlarge gold deposit newlydiscovered in western Qinling erogenic belt, hosted within the Permian-Triassic limestones and dolomites,as well as Jurassic conglomerates. It has been termed Carlin-type and hot spring-type gold ore, yet its origin is enigmatic. It is characterized by the formation of sedimentary and replacement bodies of hematite-hydrothermalsiliceous rocks above and adjacent to orebodies. The orebodies themselves exhibit a variety of geometries,such as funnels, pipes, sack-like, tabular zones parallel to bedding. NWW-EW striking, nearly SNstriking and NEE-NE striking faults control the ore-fluid passages. The orebody sites and shapes arelargely controlled by the intersection of such different strike faults. The ore mineral assemblage is characteristically gold-hematite-chalcedony. The gold mineralizationand hematitization and silification are closely interrelated. Five basic ore types are recognized: laminated-

关键词： continental hydrothermal sedimentation superlarge gold deposit Dashui Gansu.

GRANITOIDS AND TETONIC EVOLUTION OF THE WEST KUNLUN OROGENIC BELT

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地学前缘 2000年第S1期7卷 228-229页

作者： Wang Yuanlong 1,Bi Hua 2. Wang Zhonggang 2. Zhu Xiaoqing 2.(1.institute of Geology And Geophysics, chinese Academy of Science, Beijing 10002.,{2. 2.institute of {4., chinese Academy of Science, guiyang 550002.{2.)

The West Kunlun orogenic belt, one of the least studied areas in china, is located at the junction between the Qinghai—Tibetan Plateau and Tarim Basin and has undergone intense tectonic action and frequent *** West Kunlun orogenic belt can be divided into five tectonic\|magmatic evolution stages according to the character of the igneous rocks, metamorphic rocks, sedimentation mode, tectonic phases and isotopic ages(Fig 1).Active stages have dominated with only short intervening stable stages. This kind of evolution is not simply repeated but that a later stage is elevation and development of its former ***\|time distribution of granitoids varies with each different tectonic\| magmatic stage as well as within different periods of the same tectonic\| magmatism stage. Take time into condition , It is an important turning movement of tectonics\|magmatism evolution during the Indo\|Sinian movement, as space the middle fault (Jiang Chunfa 1982. of the West Kunlun orogenic belt is a significant border o f tectonics\|magmatism evolution. Granitoids formed before Indo\|Sinian movement are mainly distributed to the north of the middle fault of West Kunlun. These granitoids are mostly granites of early and middle Proterozoic, Caledonian and Hercynian ages. A unique control on the granitoid evolution is that they become younger from NE to SW, crossing the regional structure line. Granitoids formed after Indo\|Sinian movement are mainly distributed to the south of the middle fault. But distribution of granitoids of early Yanshan cycle cut across the middle fault of West Kunlun Mountain. Their age distribution shows a bidirectional control with the granitoids becoming younger across the regional structural lines from NE and SW boundary fault to the interior of the fracture belts.

关键词： the West Kunlun orogenic belt tectonic\|magmatic evolution gr anitoids

H_2. in channel of pegmatitic beryl and its hydrogen isotopic composition

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chinese Science Bulletin 1999年第S2期44卷 38-40页

作者： ZHANG Hui, LIU Congqiang and MA Yingjun Open Laboratory of Ore Deposit geochemistry, Intstitute of geochemistry, {2. Academy of Sciences,{3. Open Laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

AT present, it is universally accepted that pegmatite can be crystallized from volatile-rich peraluminousresidual granitic melt in a relatively closed environment from liquidus to solidus. However, there still exist controversies on the properties of magmatic/hydrothermal transition, the presence of an independentfluid-phase and internal evolution in the system of equilibrium, the crystallization temperature of mineralstructural zones, the time and scale of the occurrence of metasomatosis and the process of rock/fluid interaction. The method of crush-leach analysis of fluid inclusions is still widely used in the study of theproperties of magmatic/hydrothermal transition because analysis of single inclusion is limited by the techniques. Thus the result of crush-leach analysis unavoidably encounters the contamination from inclusionsof multi-generations. Recently, Taylor and Giuliani et al. successively provided some important information about the volatile evolution （mainly H2./sub>O） of pegmatite and genesis of emerald ore deposits by use

关键词： beryl mineralogy H2. in channel hydrogen isotope.

Proposal and prospects for the global Lower-Middle Cambrian boundary

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Progress in Natural Science:Materials International 2004年第12期 1-6页

作者： ZHAO Yuanlong 1*, YUAN Jinliang 2. PENG Shanchi 2. GUO Qingjun 3. ZHU Lijun 1, PENG Jin 1 and WANG Pingli 1(1. College of Resource and Environment of Guizhou University of Technology, guiyang 550003. china 2. Nanjing {4. of Geology and Palaeontology, {3. Academy of Sciences, Nanjing 2.0008, china 3. institute of geochemistry, {3. Academy of Sciences, guiyang 550002. china) CollegeofResourceandEnvironmentofGuizhouUniversityofTechnology Guiyang550003China NanjinginstituteofGeologyandPalaeontology ChineseAcademyofSciencesNanjing210008China instituteofgeochemistry ChineseAcademyofSciencesGuiyang550002China

In recent years paleontologists have been working on the global stratotype section and standard point (GSSP) for the Lower Middle Cambrian boundary in North America, china, Morocco, Spain and Russia. Continually, they suggest the potential first appearance datum (FAD) of the Middle Cambrian, such as Oryctocephalus indicus, Ovatoryctocara granulata, Acadoparadoxides mureroensis, Hupeolenus and Arthricocephalus chauveaui as being relevant to the potential stratotype section for the Lower Middle Cambrian boundary. There are only a few trilobites distributed widely enough in the Early to Middle Cambrian connection, so virtually no trilobite(s) can act as the FAD for the global Middle Cambrian. The easily identified Oryctocephalus indicus is widely distributed in three realms of the global Cambrian. Its first appearance position is linked to the extinction of old species coevolution of new ones. It appears to be a comparatively good FAD of Middle Cambrian. The continuous and unbroken Wuliu section (Balang, Taijiang County, Guizhou Province, china) includes O. indicus and co occurs with many benthic and nektonic trilobites. The evolution of acritarchs in the section, the changed characteristics of trace elements (REE and C isotopes) are generally consistent with the evolution of trilobites both above and below the boundary. Strata above the boundary yield the famous Kaili Biota. The Wuliu section is easily accessible from a main highway.

关键词： Lower-Middle Cambrian boundary GSSP Taijiang Wuliu section Oryctocephalus indicus FAD (first appearance datum).

The first finding of superhigh concentration of REE-rich bed in carbonate rock weathering crusts and its siginificance

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chinese Science Bulletin 1999年第S2期44卷 104-106页

作者： JI Hongbing, WANG Shijie, ZHOU Dequan, OUYANG Ziyuan and SUN Chengxing State Key Laboratory of Environmental geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. State Key Laboratory of Environmental geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE Pingba soil profile developed on the bedrock Triassic dolomitite and morphologically located in uplandin karst terrain in Central Guizhou, china was proven to be in-situ dolomitite weathering pedogeneticproduct. Continuous sampling method was used for taking samples from man-made excavated pit fromthe Pingba profile. REE for samples was measured on ELEMENT ICP-MS in the institute of {2., CAS. The standard reference samples GSR-6 and GSS-1,4.7 were used to monitor the precisionof REE measurement. The measurement error was less than ≤10%. For PB-T1 sample, the coefficientof variation (CV) of three analytical run precision is: La, Ce, Pr, Nd, Ho, Er≤10%; Sm, Eu, Dy,Tm≤15%; Y, Lu, Gd, Tb≤2.%.

关键词： superhigh REE concentration weathering crust carbonate rock.