闽西天井坪组和大金山组斜长角闪岩成因特征

THE ORIGIN FEATURES OF AMPHIBOLITES IN TIANJINGPING AND DAJINSHAN GROUPS IN THE WEST OF FUKIANS

本文试用同一地区早—中元古代的大金山组和天井坪组中的斜长角闪岩进行岩石学和变质作用的对比后，认为这两组地层中的该类岩石有相同的原岩，经历过相近的变质作用，经过类同的地质作用，具有相同的物源，是在相同的大地构造环境中形成的产物。就目前掌握的材料来看，天井坪地区的变质岩不具备晚太古代岩石的成因特征。因此，新建天井坪组（Ａｒ￣２ｔ），将其归属于上太古界是不妥当的。

This paper tries to make comparisons between the amphioolites in Dajinshan strata of early-middle Proterozoic era and the ones of Tianjingping of the same area on petrology and metamor-phism.It is considered that the rock in the two stratas has the same protolith and had suffered similar metamorphism. They have the same source substances and the same geologic process,being the prod-ucts formed in the same geotectonic settings.As far as the data grasped now are concerned,the meta-morphic rock in Tianjingping area is not of the origin features of late Ar rock.It is not appropriate for the newly-established Tianjingping Group(Arzt)to be thought as upper Archaeozoic erathem.