中国内蒙中部孔兹岩系中石墨矿的构造成因

内蒙中部孔兹岩系分布区可以划分为三个构造单元,其成矿作用明显不同,石墨矿主要分布在单元Ⅰ中。韧性剪切、多期褶皱叠加等变形作用,改造和控制了石墨矿的分布、产状和规模,结果形成一系列品位较高、形态规则、分布集中的石墨矿体。综合碳同位素比值和原生环境分析结果,表明石墨矿中的碳属有机成因。

THE TECTONIC ORIGIN OF GRAPHITE DEPOSITS IN THE KHONDALITE GROUP, THE MIDDLE PART OF INNER MONGOLIA, CHINA

In the middle part of Inner Mongolia, the Khondalite Group,which is the mid-upper Jining Supergroup, contains many graphite deposits. The region con- sists of three domains, Ⅰ, Ⅱ, Ⅲ, whose mineralizations are different from each other. The ductile shear and polyphase fold deformation remade and controlled the distribution, occurrence and size of graphite deposits ,resulting in formation of many large and economical ore bodies. Both the carbon isotopic compositions and analyses of the original environment of graphite and related rocks suggest that the carbon of graphite deposits is of organic origin.