Geology of the Proterozoic basement rocks and Permo-Triassic allochthons in the Geonggi massif, Korean Peninsula

朝鲜半岛的京畿地块包括麻粒岩和角闪岩相单元，它们被广泛的糜棱岩带分隔开。远离糜棱岩带的麻粒岩的CHIME年龄约为1860Ma。糜棱岩带附近的麻粒岩经韧性剪切后在石榴石颗粒周围生长堇青石和黑云母聚集体，在约1860 Ma的独居石颗粒上和内部形成247 ~ 240ma的独居石域。角闪岩相单元中的副长岩含有新元古代碎屑锆石颗粒和独居石颗粒，变质年龄为251 ~ 243ma。两个地壳单元在合并之前经历了不同的演化历史。二叠系—三叠系角闪岩相单元在苏鲁造山时期脱离扬子地块，逆冲于华北地块麻粒岩相单元之上。二叠系-三叠纪变质叠印是热异体的接触变质作用所致。

The Gyeonggi massif in the Korean Peninsula comprises granulite-and amphibolite-facies units that are separated by an extensive mylonite zone. Granulites distant from the mylonite zone yield CHIME ages of c. 1860Ma. Granulites near the mylonite zone show growth of cordierite and biotite aggregates around garnet grains after the ductile shearing, and yield 247-240Ma monazite domains on and within c. 1860 Ma monazite grains. The paragneisses in the amphibolite-facies unit contain Neoproterozoic detrital zircon grains and monazite grains with unequivocal metamorphic ages of 251-243Ma. Two crustal units underwent differing evolutional histories prior to amalgamation. The Permo-Triassic amphibolite-facies unit detached from the Yangtzu block and was thrust over the granulite-facies unit of the North China block during the Sulu orogeny. Permo-Triassic metamorphic overprints on the latter are attributed to contact metamorphism from the hot allochthon.