Granulite and Eclogite Facies Metamorphism of the Carolina Arc Terrane: Implications for Pre-Alleghanian Collision Tectonics in the Southern Appalachians

[805155] dennis本项目是对南卡罗来纳山前中部榴辉岩和相关高质岩石的分布、起源和P-T-t历史的详细研究，将阐明前阿勒卡尼亚碰撞在卡罗来纳地体演化中的作用，并为其他碰撞造山带高压岩石的形成和发掘提供见解。我们对这些榴辉岩及其封闭片麻岩的研究工作将包括：(1)详细制图（1:24 000），确定榴辉岩相岩及其封闭片麻岩在选定四边形中的分布；(2)基于原生矿物相化学分带、逆行矿物组成和石榴石矿物包裹体计算古P-T-t路径；在包裹体套件中寻找可能的超高磷矿物组合。计算包覆片麻岩的古P- t -t路径，寻找包覆片麻岩中残余的高P组合。(3)利用全岩量微量元素地球化学方法，结合它们的分布和年龄关系，确定榴辉岩及其包覆片麻岩的原岩。

9805159DennisThis project is a detailed study of the distribution, origin, and P-T-t history of eclogites and associated high grade rocks in the central Piedmont of South Carolina that will illuminate the role of pre-Alleghanian collisions in the evolution of the Carolina terrane, and provide insights into the formation and exhumation of high pressure rocks in other collisional orogens. Our work on these eclogites and their enclosing gneisses will include: (1) Detailed mapping (1:24,000) to determine the distribution of eclogite facies rocks and their enclosing gneisses in selected quadrangles; (2) Calculation of paleo P-T-t paths based on chemical zonations in the primary mineral phases, retrograde mineral compositions, and on mineral inclusions in garnet; search for possible ultra-high P mineral assemblages in the inclusion suites. Calculation of paleo P-T-t paths for the enclosing gneisses, and search for relict high P assemblages in the enclosing gneisses. (3) Determination the protoliths of the eclogites and their enclosing gneisses by whole rock major and trace element geochemistry, combined with their distribution and age relationships.