投稿时间：2016-12-22
修订日期：2017-10-30
网络发布日期：2018-02-28
中文摘要:黔湘渝毗邻区是中国南华纪黑色页岩型锰矿的集中产区，近年来在该区域的找矿勘探取得重大进展。但是，该区域内黑色页岩型锰矿的成矿物质来源、成矿机制以及沉积盆地的氧化还原环境及其与成矿的关系尚存争议。文章对贵州高地锰矿的菱锰矿开展了详细的碳、氧同位素研究，样品采自钻孔岩芯，测试结果表明其δ13CV-PDB值和δ18OV-PDB值全部为负值，变化范围分别在-11.5‰~-6.8‰和-15‰~-3.9‰之间。结合前人研究成果，认为黔湘渝毗邻区南华系形成时古海洋处于氧化还原的分层状态，含锰的陆源碎屑物质通过海水的分解作用首先形成氧化锰和氢氧化锰，在浅水滞留盆地环境下古海水由弱氧化状态转变为还原状态，并在有机质降解作用的促使下使锰的氧化物和氢氧化物转化成菱锰矿，并富集沉积形成大塘坡组黑色页岩型菱锰矿矿床。
Abstract:The Guizhou-Hunan-Chongqing border area is a concentrated region of black shale-hosted manganese in China, where a number of large Mn ore deposits formed during Nanhua Period have been discovered in recent years. However, there still exists controversy with respect to the origin of manganese, the processes of mineralization, and redox conditions of seawater during manganese precipitation. In this paper, the authors present carbon and oxygen isotope data of manganese carbonate and Mn-rich black shales from the Gaodi Mn deposit in Tongren area, Guizhou Province. Both δ13CV-PDB and δ18OV-PDB show negative values, from -11.5‰ to -6.8‰ and from -15‰ to -3.9‰, respectively. In combination with previous published data, the authors have reached the conclusion that there was a redox stratified structure of the Nanhua Ocean in the Guizhou-Hunan-Chongqing border area. Mn-rich detrital components first fluxed into ocean and precipitated Mn (hydr)oxides under suboxic conditions. Consequently, due to restricted basin condition of this area, seawater was changed to anoxic condition and led to conversion of Mn (hydr)oxides to manganese carbonate. Such process was catalyzed by decay of organic carbon.
文章编号：
中图分类号：P618.32;P597
文献标志码：
基金项目:本文得到国家自然科学基金项目（编号：41403008）、中央公益性科研院所基本科研业务费项目（编号：YWF201406）和国土资源调查项目（编号：12120115069801）的联合资助
引用文本：
瞿永泽,徐林刚,毛景文,潘文,占朋才,安正泽.2018.贵州铜仁地区南华系大塘坡组黑色页岩型菱锰矿碳、氧同位素特征及锰矿成矿作用[J].矿床地质,37(1):50~66JU YongZe,XU LinGang,MAO JingWen,PAN Wen,ZHAN PengCai,AN ZhangZe.2018.Carbon and oxygen isotope characteristics and mineralization of black shale-hosted manganese carbonate of Datangpo Formation in Tongren, Guizhou Province[J].Mineral Deposits37(1):50~66
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