龙岗古陆南缘光华岩群地质特征及时代探讨  

A study on the geologic features of the Longgang Guanghua terrain on the southern margin of the ancient land and its age

作　　者：欧祥喜[1] 马云国 

机构地区：[1]吉林省地勘局区域地质矿产调查所,吉林长春130022

出　　处：《吉林地质》2000年第3期16-25,共10页Jilin Geology

摘　　要：吉林省通化市北部光华乡一带 ,发育有一套由变质基性席状岩墙、变质气孔状玄武岩、黑云变粒岩、大理岩、含榴二云片岩、变质流纹岩为组合的中—浅变质岩系。该套岩系岩石组合、变质程度均有别于龙岗古陆内的太古宙上壳岩。具有陆内裂谷环境下形成的双峰式火山岩建造特征。依据区域地层对比、岩石组合特征、同位素年龄资料 ,与周围侵入岩的相互关系 ,结合本地区地壳演化历史综合分析认为 ,其形成时代当属早元古宙 ,建立光华岩群。A suite of middle-shallow metamorphic rock series with the metamorphic basic sheet dike, metamorphic vesiculate basalt, biotite metaconglomerate, marble, garnet-bearing muscovite-biotite schist and metamorphic rhyolite is developed in the Guanghua village, northern Tonghua City, Jilin province. The rock series is different with the Archeozoic supracrust in rock association and metamorphic degree within the Longgang ancient land, having bimodal volcanic rock formational feature with the intracontinental rift environment. On the basis of the regional stratigraphic correlation, rock association characteristics, isotopic age, mutual relation with adjacent intrusive rocks and combining with the comprehensive analysis of the crust evolutional history, it should be early Proterozoic and established as Guanghua Group.

关 键 词：光华岩群 席状岩墙 陆内裂谷 变质变形 早元古宙 

分 类 号：P534.3[天文地球—古生物学与地层学]