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Zhou J.-X.,Chinese Academy of science | Gao J.-G.,Kunming University of Science and Technology | Chen D.,Guizhou Nonferrous Metal and Nuclear Industry Geological Exploration Bureau | Liu X.-K.,Kunming University of Science and Technology
International Geology Review | Year: 2013

The Tianbaoshan Pb-Zn deposit, part of the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province, is located in the western Yangtze Block and contains 2.6 million tonnes of 10-15 wt.% Pb + Zn metals. Ore bodies occur as vein or tubular types and are hosted in Sinian (late Proterozoic) carbonate rocks and are structurally controlled by the SN-trending Anninghe tectonic belt and NW-trending concealed fractures. The deposits are simple in mineralogy, with sphalerite, galena, pyrite, chalcopyrite, arsenopyrite, freibergite, and pyrargyrite as ore minerals and dolomite, calcite, and quartz as gangue minerals. These phases occur as massive, brecciated, veinlet, and dissemination in dolostone of the upper Sinian Dengying Formation. Hydrogen and oxygen isotope compositions of hydrothermal fluids range from -47.6 to -51.2‰ and -1.7 to +3.7‰, respectively. These data suggest that H2O in hydrothermal fluids had a mixed origin of metamorphic and meteoric waters. Carbon and oxygen isotope compositions range from -6.5 to -4.9‰ and +19.3 to +20.2‰, respectively. These compositions plot in the field between mantle and marine carbonate rocks with a negative correlation, suggesting that CO2 in the ore-forming fluids had multiple sources, including the Permian Emeishan flood basalts, Sinian-to-Permian marine carbonate rocks, and organic matters in Cambrian-to-Permian sedimentary rocks. Sulphur isotope compositions range from -0.4 to +9.6‰, significantly lower than Cambrian-to-Permian seawater sulphate (+15 to +35‰) and sulphate (+15 to +28‰) from evaporates in Cambrian-to-Permian strata, implicating that the S was derived from host-strata evaporates by thermal-chemical sulphate reduction. 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios range from 18.110 to 18.596, 15.514 to 15.878, and 38.032 to 39.221, respectively, which plot in field of the upper crust Pb evolution curve, unlike those of Proterozoic basement rocks, Sinian dolostone, Devonian-to-Permian carbonate rocks, and the Permian Emeishan flood basalts, implying complex derivation of Pb metal in the ore-forming fluids. Geological and isotopic studies of the Tianbaoshan Pb-Zn deposit reveal that constituents in the hydrothermal fluids were derived from multiple sources and that fluid mixing was a possible metallogenic mechanism. The studied deposit is not distal magmatic-hydrothermal, sedimentary exhalative (SEDEX), or Mississippi Valley (MVT) types, rather, it represents a unique ore deposit type, named in this article the SYG type. © 2013 Taylor and Francis Group, LLC. Source

Gu J.,Chinese Academy of science | Gu J.,University of Chinese Academy of Sciences | Huang Z.,Chinese Academy of science | Fan H.,Chinese Academy of science | And 3 more authors.
Journal of Geochemical Exploration | Year: 2013

The lateritic bauxite deposits in the Wuchuan-Zheng'an-Daozhen area, Northern Guizhou Province, are hosted by the Liangshan Formation which unconformably overlies the Lower-Middle Silurian mud-shale and the Upper Carboniferous limestone and underlies the Middle Permian limestone. From the bottom upward, the deposits are generally composed of brick-red, yellow-brown, and gray bauxite horizons. Diaspore, boehmite, kaolinite, smectite and hematite are the major mineral components in the bauxite ores with small amounts of gibbsite, illite, goethite, pyrite, anatase, zircon, quartz and feldspar. The textural features of ores suggest that the bauxite has an authigenic origin but locally underwent transportation and re-deposition. Geochemical investigations indicate that the immobile elements like Al, Ti, Zr, Cr, Hf, Nb, Ta and Th were obviously enriched during bauxitization. Factors such as the type of parent rock, pH variation in weathering solutions, adsorption processes, groundwater chemical characteristics, Fe concentration variation in the weathering profiles, leaching degree of minerals, and geochemistry of elements have played a significant role in the distribution of trace and rare earth elements during weathering of the lateritic bauxite. The bauxites may have a close genetic relationship with the Hanjiadian mud shale and the Huanglong limestone in view of their similar chondrite-normalized REE patterns, Zr/Hf and Nb/Ta ratios. However, field observations and geochemical data suggest that the precursors of bauxites are complex and the main components of precursors are basic igneous rocks possibly from the Neoproterozoic basic igneous rocks and the Mesoproterozoic basic-ultrabasic intrusions in the Yangtze Block. © 2013 Elsevier B.V. Source

Gu J.,Chinese Academy of science | Gu J.,University of Chinese Academy of Sciences | Huang Z.,Chinese Academy of science | Fan H.,Chinese Academy of science | And 3 more authors.
Journal of Asian Earth Sciences | Year: 2013

The provenance of the large and super-large scale bauxite deposits developed in the Wuchuan-Zheng'an- Daozhen (WZD) alumina metallogenic province in the Yangtze Block of South China is poorly understood. LA-ICP-MS and SIMS U-Pb dating of detrital zircons from bauxite ores and the underlying Hanjiadian Group in the WZD area provide new constrains on the provenance of the WZD bauxite and provide new insight on the bauxite ore-forming process. The ages of the detrital zircons in the bauxites and the zircons in the Hanjiadian Group are similar suggesting that the bauxites are genetically related to the Hanjiadian sediments. The detrital zircon populations of the four samples studied show four primary age peaks: 2600-2400 Ma, 1900-1700 Ma, 1300-700 Ma and 700-400 Ma. The age distribution of detrital zircons indicates that they are probably derived from various sources including Neoproterozoic, Mesoproterozoic, Paleoproterozoic, Archean and some minor Paleozoic sources. The most abundant age population contains a continuous range of ages from 1300 to 700 Ma, ages consistent with subductionrelated magmatic activities (1000-740 Ma) along the western margin of the Yangtze Block and the worldwide Grenville orogenic events (1300-1000 Ma). Thus, it is suggested that the main provenances of the WZD bauxite and the Hanjiadian Group are the Neoproterozoic igneous rocks in the western Yangtze Block and the Grenville-age igneous rocks in the southern Cathaysia Block. In addition, this work verifies that the global Grenville orogenic events and subduction-related magmatic activities associated with the Yangtze Block had a significant influence on the formation of the WZD bauxite deposits. © 2013 Elsevier Ltd. Source

Jin Z.,Guizhou Nonferrous Metal and Nuclear Industry Geological Exploration Bureau | Zhou J.,Chinese Academy of science | Huang Z.,Chinese Academy of science | Gu J.,Chinese Academy of science | And 2 more authors.
Earth Science Frontiers | Year: 2013

Bauxite deposits in the Wuchuan-Zheng'an-Daozhen district, an important part of the south Chongqing-north Guizhou Al metallogenic province, are the main Al-enrichment region in Guizhou Province. The bauxite deposits are hosted in the Middle Permian Liangshan Formation, which lies on the erosion surface between Permian Qixia Formation and Carboniferous Huanglong Formation or Silurian Hanjiadian Formation. Four detrital zircon samples from three typical bauxite deposits were analyzed by Secondary Ion Mass Spectrometry(SIMS) for U-Pb dating. The results show that the range of 206Pb/238U ages are large, almost all of the data are plotted on the U-Pb concordant curve and can be divided into five groups: i.e, 433-591 Ma, 740-1000 Ma, 1031-1442 Ma, 1700-1800 Ma and 2300-2400 Ma, of which the age groups of 433-591 Ma, 740-1000 Ma and 1031-1442 Ma are related to Silurian-Cambrian, Neoproterozoic Qingbaikouan and Mesoproterozoic undetermined periods, respectively. It implies that the ore-forming near source materials of the bauxite deposits are mainly detrital rocks in the Lower Silurian Hanjiadian formation, which were derived from the original distant sources-mainly metamorphosed volcanic sedimentary rocks in the Neoproterozoic and the Mesoproterozoic, which are related to the breaking of the Rodinian supercontinent, to the collision between Yangtze block and Cathaysia block, and to the Gvenille orogeny in the Mesoproterozoic. In this research, the youngest U-Pb age from the four samples is 303.1 Ma, which suggests the records of the crustal uplift, the denudation and the regional magmatism in the Late Carboniferous-Early Permian caused by Guizhou-Guangxi Movements. Source

Jin Z.-G.,Guizhou Nonferrous Metal and Nuclear Industry Geological Exploration Bureau | Zhou J.-X.,Chinese Academy of science | Huang Z.-L.,Chinese Academy of science | Dai L.-S.,Kunming University of Science and Technology | And 3 more authors.
Geology in China | Year: 2015

Li, Ga and Sc are important rare noble metal resources, which are widely distributed in the bauxite. More than ten large- sized bauxite deposits have been found in the Wuchuan-Zheng' an-Daozhen bauxite ore district in northern Guizhou Province, and the associated Li, Ga and Sc resources are very abundant. The authors chose the typical Wachangping, Xinmin and Xinmu-Yanxi bauxite deposits in Wuchuan-Zheng'an-Daozhen area as the study case, investigated the distribution regularity of Li, Ga and Sc by analyzing their content in ore-bearing rocks and their overlying and underlying rocks. The results show that the values of Li, Ga and Sc decrease from the central ore-bearing rock series to the bottom and then to the upper part vertically. In addition, the values of Li in massive ores are higher than those in clastic ores, and they are all higher than values in earthy ores; Ga is concentrated in earthy and massive ores, whereas Sc is concentrated in clastic ores. Additionally, the regional distribution of Ga, Li and Sc is higher in the north and lower in the south, suggesting their relationship with lithology, weathering and sedimentary differentiation. Ga, Li and Sc mainly exist on the surface of rutile, zircon and xenotime. Hence these heavy minerals are very important for comprehensive utilization of Li, Ga and Sc. The distribution regularities of Li, Sc and Ga suggest that the bauxite was formed in a continental lacustrine basin environment. Source

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