辽西太古代建平变质杂岩的地球化学和变质作用的PTt轨迹

太古代建平变质杂岩主要由高Na/K比的、原岩为英云闪长岩-奥长花岗岩-花岗闪长岩系列(TTG)侵入岩的中性麻粒岩和片麻岩、少量变沉积岩、基性麻粒岩、斜长角闪岩和变超基性岩组成。各类岩石具有明显不同的地球化学特征。结合野外关系考虑,斜长角闪岩和基性麻粒岩可与世界其他高级区内的变质拉斑玄武岩对比;TTG片麻岩,中性麻粒岩、紫苏花岗岩和斜长质片麻岩可能由镁铁质源岩部分熔融而成。变质作用的演化轨迹为反时针型。因此,本区可与冀东、内蒙、南印度和苏格兰的刘易斯等高级地体对比。

GEOCHEMISTRY AND METAMORPHISM P-T-t PATH OF THE ARCHAEAN JIANPING METAMORPHIC COMPLEX IN WESTERN LIAONING PROVINCE

The Archaean Jianping metamorphic complex in western Liaoning Province mainly consists of high Na/K gneisses and intermediate granulites of tonalite-trondhjemite-granodiorite (TTG) composition, while metasediments, basic granulites, amphibolites as well as metaultrabasic rocks are rare.Rocks of different types show obvious different geochemical characteristics. In terms of field relationships and geochemistry, the amphibolites and granulites can be comparable to meta-tholeiites in other high-grade terranes over the World, while TTG gneisses, intermediate granulites, charnockites and anorthosites are interpreted to be derived by partial melting of a marie source. The metamorphism of Jianping metamorphic complex shows an anticlockwise type P-T-t path. The Jianping metamorphic complex is comparable in rock types and geochemistry to high-grade terranes in Eastern Hebei and Nie Mongol, China, southern India, and the Lewissian of NW Scotland.