华北陆台高压麻粒岩－榴闪岩韧性剪切带

The Ductile Searing Belts of High-Pressure Granulite-Garner-Amphibolite in North China Platform

晋冀蒙交界地区存在着隶属于不同地质时期、不同构造演化历史阶段的３条地壳规模的高压麻粒岩－榴闪岩韧性剪切带。其特征的矿物组合是石榴石－单斜辉石－斜长石－石英或石榴石－斜长石－普通角门石，发育明显的减压结构。残留高压麻粒岩的平衡条件高者温度可达８２０－９１０℃，压力达互．２—１．５ＧＰａ，推断它们为不同地质时代地体（微地体）碰撞或拼合所形成。研究区不同时代、不同层群及变质杂岩系较高级的构造岩石单位（单元）均以高压麻粒岩－榴闪岩韧性带相接触，这在早前寒武纪地壳演化进程中，几乎成为一个普遍性的规律。

Between the Chongli Complex Group and the Hongqiyingzi Complex Group, the highgrede metamorphic green stone belts of the Jiangouhe and Shuidizhuang Formations of the Lower Subgroup of the Chongli Complex Group,which were intruded by the Xiwanshan granulite complex and Changyukou hypersthene, and the Aijiagou Formation (Khondalite rock series)of the Upper Subgroup of the Chongli Complex Group,and the Jiangouhe Formation and Shuidizhuang Formation of the Lower Subgroup of the Chongli Complex Group there exist three crust-scale ductile shearing belts of high-pressure granulite-gsrnet comphibolite, which originated in the different Periods and under went the different evolutional singes. The characteristic mineral assemblage is garnet-clinopyroxene-plagiodase-guartz of garnet-plagiodase-hornblende with apparent pressure-decreasing texture. The equilibrium condition of relict high-pressure granulite are as high as 820-910℃ and 1. 2-1. 5GPa. It is inferred that they were originated by collision or accretion of different time terrains(microterrains). All the high-grade tectonolithologic units of different time strata-group and metumorphic complexes tube ductile shearing belts of high-pressure granuliie-garnet-amphibolite as their mutual contacts. This feature is almost a general regularity in the Early Precambrian evolution.