大别造山带浅变质岩的地质-地球化学特征及成因机制

大别造山带超高压变质带内部及其北缘，出露仅经过绿片岩相变质作用的浅变质岩系。通过对部分浅变质岩的区域分布、地质特征及地球化学的综合研究表明，这些浅变质岩系形成于新元古代扬子板块北缘的裂陷盆地中，并遭受新元古代岩浆侵位和以寒冷气候位特征的大气降水热液蚀变，共同经历了与扬子大陆板块俯冲-碰撞过程中有关的构造热事件；因此认为这些浅变质为扬子板块俯冲过程中被“刮”下来的构造残片，为大陆板块俯冲过程中形成的加积杂岩，并为扬子板块与华北板块的俯冲和碰撞的动力学过程提供有力的科学佐证。在此基础上，厘定了大别造山带浅变质岩的形成及其与扬子大陆板块俯冲的构造模型。

GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF LOW GRADE METAMORPHIC ROCKS AND ITS TECTONICS MECHANISM IN DABIE OROGENIC BELT

There are low-grade metamorphic rocks which underwent greenschist facies metamorphism in the middle and north margin of the Dabie ultrahigh pressure(UHP) metamorphic belt.The study of distribution,geology character and geochemistry of the low-grade metamorphic rocks indicates that the original rocks of the low-grade metamorphic rocks and part of the high pressure-UHP rocks were related to the subduction-collision of the Yangtze plate,and the that the low-grade metamorphic rocks are the structure tags which due to subduction of Yangtze plate.It can be used to the places of the subduction belt and suture belt of Dabie orogenic belt and the accretionary complex with subduction of the continental plate .The accretionary complex provid+es evidence for the dynamics process of collision between the Yangtze plate and North China plate.