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Fluid inclusion evidence for the involvement of organic matter in mineralization of Hg, Sb and Au deposits

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chinese Science Bulletin 1999年第S2期44卷 197-199页

作者： SHI Jixi~1 and WANG Huayun~2.1. Open Laborator of Ore Deposit geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. 2. institute of Guizhou Provincial Bureau of Geology and Mineral Resoarces, guiyang 550001, china Open Laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China institute of Guizhou Provincial Bureau of Geology and Mineral Resources Guiyang 550001 China

1 Research significance and study area geochemistry of organic matter in metallic ore deposits and the role of organic matter in metallogenesisare the hot subjects of research in the field of ore deposits and also a weak link in this field. Widespreadin the areas of Tongren, Danzhai, etc. in eastern Guizhou (simplified as southeastern Guizhou or Qiandongnan below) are large-sized Hg (dominant), Sb, and Au deposits, while in the areas of Qinglong,Xingren, Zhenfeng, Anlong, etc. In southwestern Guizhou (simplified as southwestern Guizhou orQianxinan below) are a number of large-sized and extremely large-sized microfine disseminated gold deposits and Sb and Hg deposits. Studies have shown that their ore-forming temperatures are estimated al2.0℃ for most Au deposits, respectively, allof them belonging to the typical low-temperature deposits. Not a few researchers have found bitumens

关键词： organic matter fluid inclusion epithermal Hg-Sb-Au deposit.

Trace element compositions of volcanic rocks from Yangba Formation, Bikou Group, Qinling, china: Implications for tectonics

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chinese Science Bulletin 1999年第S2期44卷 203-204页

作者： DING Zhenju~(1,2. and LlU Congqiang~1 1. institute of geochemistry, {2. Academy of Sciences,{3. 2. {4. University of Ceosciences, Wuhan 4.3}074. {4. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China china University of Geosciences Wuhan 430074 China

THE Yangba Formation of Bikou Group is located in south Qinling, a famous orogenic belt separating chinese continent into two parts: North china plate and Yangtze plate. The Yangba Formation comprises themafic and felsic volcanic rocks formed in an ancient seafloor environment during Proterozoric era. Thesuites of mafic and felsic volcanic rocks petrochemically are divided into tholeiite and calc-alkalinedacite, respectively, showing clearly characteristics of bimodal volcanic rock mainly with lithology andmajor element composition, and a lack of typical intermediate rocks. These indicate that the volcanicrocks of Yangba Formation were generated in rift tectonics setting. The tholeiites of Yangba Formation are similar in trace element compositions to Mid-ridge basalt,displaying a slight depletion to enrichment in light rare earth elements (LREEs) (La/Yb_n=0.6-1.{2..slight fractionation between LREE (La/Sm_n=0.55-1.1{2. and HREE (Gd/Lu_n=1.09-1.50),

关键词： trace element volcanic rocks tectonics.

Dehydration melting of solid amphibolite at 2.0 GPa: Effects of time and temperature

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Science china Earth Sciences 2005年第8期48卷 1120-1133页

作者： ZHOU Wenge1, XIE Hongsen1, LIU Yonggang1, ZHENG Xiaogang1, ZHAO Zhidan2.& ZHOU Hui3.1. Laboratory of Material in the Earth’s Interior, institute of {2., chinese Academy of Sciences,{3. 2. Department of Geology, china University of Geosciences, Beijing 100083. china 3. Department of Geology, Peking University, Beijing 100871, china 1. Laboratory of Material in the Earth’s Interior Institute of Geochemistry Chinese Academy of Sciences 550002 Guiyang China 2. Department of Geology China University of Geosciences 100083 Beijing China 3. Department of Geology Peking University 100871 Beijing China

Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12.2.0 h. One is keeping the pressure at 2.0 GPa and the annealing time of 12.h, changing the temperature (800―1000℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (12.2.0 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 12.h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 104.Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.

关键词： solid amphibolite, high pressure, high temperature, time, partial melting.

Dynamic processes of ore-forming fluid and the localization of orebody: case study on the sediment-hosted gold deposits of southwestern Guizhou, china

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chinese Science Bulletin 1999年第S2期44卷 263-265页

作者： ZHANG Chengbo and ZHANG Zheru institute of geochemistry, {2. Academy of Sciences,{3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

1 Geological setting and occurrence features of the sediment-hosted gold deposits OVER 100 sediment-hosted gold deposits and occurrences of southwestern Guizhou lie near the sonthemedge of the Yangtze craton, which is composed of crystalline rocks of Proterozoic age, overlain mainly byPaleozoic and Lower to Middle Triassic shallow-marine platform and reef facies carbonates that gradesouthward and eastward into a thick section of interbedded siltstones and turbidite sandstones. Clasticdeposits were from the Yunkai Old Land and the Jiangnan Old Land respectively. The rocks were foldedand faulted during the Yanshanian orogeny, 190-65 Ma ago. Mineral deposits were mainly located inthe breccia horizon at the base of the Longtan Formation of Upper Permian, underlain by the massive graylimestone of Lower Permian with a karst unconformity, and the high-angle fault zones in the Triassicargillaceous limestone interlayered with shale, arkose, and fine-grained turbidite sandstone. No

关键词： sediment-hosted gold deposits fossil hydrothermal system mathematical model.

Hydrothermal sedimentation and lead-zinc deposit in Dengying formation of the Sinian system in Panxi region

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chinese Science Bulletin 1999年第S2期44卷 67-68页

作者： ZHU Laiming and RONG Tianjun institute of geochemistry, {2. Academy of Sciences,{3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

IN addition to vanadium titano-magnetite, lead-zinc ore is also one of the mineral resources with great exploring potentiality in the Panxi region of Sichuan Province, china. In the carbonate rock strata of theSinian Dengying Formation which account for about 3.5%-11.{2. of the total thickness of the strataexposed in the Panxi region there are quite a number of the Pb-Zn deposits that account for 53.{2. of thetotal Pb-Zn ore reserve in the whole region. Furthermore, some large Pb-Zn deposits such as the Tianbaoshan Pb-Zn deposit in Huili, the Daliangzi Pb-Zn deposit in Huidong and the Yinchanggou Pb-Zn deposit in Ningnan are also hosted in the Sinian Dengying Formation. Why? Previous studies indicated that the high background values of Pb and Zn, favorable lithofacies andpaleogeographic conditions and good ore-hosting structures made the Sinian Dengying Formation a pre-

关键词： hydrothermal sedimentation lead-zinc deposit Dengying formation Panxi region.

Trace elements in volcanic rocks from Yangba Formation, Bikou Group, Qinling area, china——Implications for tectonics

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chinese Science Bulletin 1999年第S2期44卷 44-46页

作者： DING Zhenju~(1,2. and LIU Congqiang~1 1. Open Laboratory of Ore geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. 2. china University of Geosciences, Wuhan 4.3}074. china Open Laboratory of Ore geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China china University of Geosciences Wuhan 430074 China

YANGBA Formation of Bikou Group is located in south Qinling, a famous orogenic belt separating chinesecontinent into two parts: North china plate and Yangzi plate. The Yangba Formation comprises the maficand felsic volcanic rocks formed in an ancient seafloor environment during the Proterozoic era. The suitesof mafic and felsic volcanic rocks are petrochemically divided into tholeiite and calc-alkaline dacite, respectively, showing characteristics of bimodal volcanic rock mainly by lithology and major element content, and a lack of typical intermediate rocks. These signatures indicate that the volcanic rocks of YangbaFormation were generated in rift tectonics setting. The tholeiites of Yangba Formation are similar in trace element content to mid-ridge basalt, displaying a slight depletion to enrichment in light rare earth elements (LREE’s) (La/Yb_n = 0.6-1.{2., slightfractionation between LREE (La/Sm_n =0.55-1.1{2. and HREE (Gd/Lu_n = 1.09-1.50), and relative flat patterns in whole. The decoupling of Eu to its neighboring elements in two samples likely indicates an effect of fractional crystallization in magma evolution. The La-La/Sm, Ni-La, Ni-Th, Ni-Ta,and Ni-Hf diagrams all support a conclusion that the mafic rocks are generated by partial melting pro-

关键词： trace element volcanic rock tectonics setting Bikou Group.

The metallogenic epoch and ore-forming metal source of some large and superlarge deposits in Laojunshan, Yunnan——Evidence from Rb-Sr isotopic studies

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chinese Science Bulletin 1999年第S2期44卷 30-32页

作者： LIU Yuping~1, LI Chaoyang~1 and ZENG Zhigang~2.1. institute of geochemistry, {2. Academy of Sciences,{3. 2. institute of Oceanography, {2. Academy of Sciences, Qingdao 2.6071, china institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China institute of Oceanography Chinese Academy of Sciences Qingdao 266071 China

THE Laojunshan metallogenic district located in southeastern Yunnan is an important tin polymetallic metallogenic district in china. The Dulong (tin-zinc polymetal, superlarge), Xinzhai (tin, large) andNanyangtian (scheelite, large) are the main deposits in this district. These deposits outcrop in the Lower-Middle Cambrian metamorphic series, and most orebodies that associated with skarns closely are stratoid,lenticular in occurrence and in accordance with the wall rocks. Distributed around the Laojunshan granite, the above-mentioned deposits were considered to be of magmatic-hydrothermal origin. But

关键词： Rb-Sr isotopes metallogenic epoch source Yunan.

An SIMS Study on the Fingerprint Characteristics of Minerals with Special Reference to Minerals from the Jinningian Granites in the Yunnan Sector of the Xikang-Yunnan Axis

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Acta Geologica Sinica(English Edition) 1991年第3期65卷 251-257页

作者： Zhou Shitao Liu Yongkang institute of geochemistry, Academia Sinica, {2. {3. institute of geochemistry Academia Sinica Guiyang 550002

In this paper such minerals as apatite, zircon and biotite from granites were determined and analyzed bysecondary ion mass spectrometry (SIMS) for their isotopic ages, REE composition, trace elements and volatilecomponents with an attempt to shed light on the origin and formation environments of the Jinningian granitesin the Yunnan sector of the Kangdian (Xikang- Yunnan) earth's axis. The results show that the apatites,zircons and biotites of different geneses possess different fingerprint characteristics. Some correlations havebeen found between trace elements and volatile components contained in the minerals from granties.

关键词： SIMS An SIMS Study on the Fingerprint Characteristics of Minerals with Special Reference to Minerals from the Jinningian Granites in the Yunnan Sector of the Xikang-Yunnan Axis Axis

Gold occurrence mechanism of fine disseminated gold deposits

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chinese Science Bulletin 1999年第S2期44卷 18-20页

作者： WANG Xiaochun and ZHANG Zheru institute of geochemistry, {2. Academy of Sciences,{3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE fine disseminated gold deposits are widely distributed in the southwestern china and western UnitedStates. They have a mineral association of pyrite, arsenopyrite, marcasite, realgar, orpiment, stibnite,cinnabar, quartz, calcite and barite, and an element association of gold, arsenic, antimony, mercury,thallium and barium. Gold occurs as disseminated and in small size. This note aims to discuss the disseminated nature and micron size of the gold.

关键词： gold mechanism fine disseminated gold deposit.