阿拉善地块东缘叠布斯格地区高压基性麻粒岩的变质作用P-T-t轨迹研究

The Diebusige Complex of the eastern margin of Alxa Block records a long-term tectonic-thermal evolutionary history of Alxa Block in Paleoproterozoic. Therefore, the metamorphic complex provides a well natural laboratory for investigating metamorphic evolution of the Paleoproterozoic collsional orgenic processes. On the basis of integrated studies of petrology, genetic nineralogy and geochemistry, this applying project will put the high pressure (HP) mafic grnulites rocks as the major study objects in the Diebusige area of the eastern margin of Alxa Block. The aim are to reveal the petrographic and mineralogic marks of the HP granulites facies of the granulite, contrast the P-T conditions for each evolutional stage and clarify the petrogensis and formational structural setting of the HP mafic granulite. On the other hand, a combined study of mineral in clusions, CL images an BSE images, U-Pb dates will provide a well-constraint on the timing of the protolith and different metamorphic events, and P-T-t path of the HP mafic granulite in the Diebusige area. finally, combined above study, the tectonic nature and dynamic evolutional process of the HP mafic granulite in the Diebusige area are taken over.

位于阿拉善地块东缘叠布斯格地区的变质杂岩记录了阿拉善地块古元古代构造-热演化历史，是研究古元古代造山带中变质作用过程的天然实验室。本项目以阿拉善地块东缘叠布斯格地区高压基性麻粒岩为重点研究对象，通过岩石学、成因矿物学和地球化学综合研究，识别高压麻粒岩相变质作用的岩相学和矿物学标志，限定不同变质阶段的P-T条件，阐明其原岩的岩石成因及其形成构造环境；在对锆石矿物包体鉴别，阴极发光和背散射图像综合分析的基础上，对锆石不同性质的微区进行定年，准确限定叠布斯格地区高压基性麻粒岩原岩形成时代和不同变质阶段变质时代的年代学格架，建立高压基性麻粒岩连续而完整的P-T-t轨迹。综合以上研究资料，最终探讨叠布斯格地区高压基性麻粒岩的构造属性与形成的动力学演化过程。