摘要
闽西永定地区的中深变质岩系经调查主要岩石组合为变粒岩、片岩、变质火山岩及少量石英岩,变质程度达低角闪岩相,构造形变特征明显有别于区域内的震旦纪楼子坝群,获得同位素年龄1825—1628 Ma。据此认为,这套变质岩不属于原划定的楼子坝群,应分属于下、中元古界。对该地层所夹变质火山岩的形成环境,本文亦进行了讨论。
The lithological association of medium-grade and hypometamorphic rocks in the Yongding area of Northwestern Fujian mainly is granoblastite, schist, matamorphic volcanic rocks and a few of quartzite, the metamorphic range of which reaches lower amphibolite facies. The characteristics of the tectonic deformation are obviously different from that of the Louziba Group strata (Sinian period) in the region. The isotopic age of the metamorphic rocks is between 1 825 and 1 628 Ma. Therefore, it is concluded that the metamorphic rocks are of Middle and Lower Proterozoic instead of Louziba Group. In the paper, the authors also have a discussion on the environment of forming the interbedded metamorphic volcanic rock in the strata.
出处
《福建地质》
1993年第4期268-279,共12页
Geology of Fujian
关键词
变质岩
地质时代
中元古代
地层
metamorphic rock, Middle and Lower Proterozoic, stratigraphic time, Yongding area
