摘要
闽中下—中元古界东华组绿片岩原岩主要为一套超镁铁质-镁铁质火山岩。其岩石学特征、岩石化学特征、区域变质特征和国外太古代的科马提岩极为相似;和桂北、湖南益阳中元古代的科马提岩也可对比,但变质程度较高,达低角闪岩相。该绿片岩自下而上分别为辉石质科马提岩、玄武质科马提岩,并伴生有拉斑玄武岩。它和上部卓地组中酸性、酸性火山岩组成一套完整的岩浆演化系列,且具有双模式特征。闽中早—中元古代科马提岩产于拉张盆地的构造环境。
In this paper, the authors have a discussion on the komatiite found in Donghua Formation of early-middle Proterozoic in Central Fujian. The prototype of green schists in Donghua Formation mainly is ultramafic-mafic volcanic rocks. The petrographic, petrochemical and regional metamorphic characteristics of the green schists are very similar to that of the Archean komatiite in some foreign countries. The green schists can also be compared with the middle proterozoic komatiite in Northern Guilin and the Yiyang area of Hunan Province, but they are higher grade in metamorphic rank, approximate to low-grade hornfels facies. The green schists from bottom to top can be divided into the pyroxene komatiite and basaltic komatiite, accompanied with the tholeiite. They, together with intermediate-acid and acid volcanic rocks in the upper part of Zhoudi Formation (early-middle Proterozoic), are made up of a complete suit of magmatic evolution series, which are possessed of the bimodal characteristics. The formation of the early-middle Proterozoic komatiite in Central Fujian is in the tectonic environment of extensional basin.
出处
《福建地质》
1992年第3期141-155,共15页
Geology of Fujian
