中国辽宁北部太古代绿岩建造

THF ARCHAEAN GREENSTONE FORMATION IN NORTHERN LIAONING PROVINCE,CHINA

中国辽宁省北部古老变质杂岩区,长期以来,为许多地质学家所注目。本文承蒙张秋生教授指导,试图从该区的区域地质背景和变质岩系的基本组合特征入手,探讨其变质地质历史的演化和变质岩系的成因。

The article has discussed the origination and evolution of the old metamor-phic complex and granitic rocks in North. Liaoning Province, China, where an Archaean metamorphic terrain, the Anshan Group, has a rather extensive outcrop, and shows typical characters of a greenstone belt to which the name Greenstone Formation has been proposed. Accordingly, the regional geological back ground of the terrain, the classification, correlation, epochs of metamorphism and mcdes of deformation of the composing metamcrphic reck units were determined.Especial attention was given to the metamorphic differentiation held at the late stage of amphibolite-phase of metamorphism which revealed the process of metamorphism was confined within a closed system where metasomatism and element transport held to minimum.The article described in detail of the metamorphic rocks, inferred the nature of the source recks, established the succession of the Greenstone Formation, determined the cycles of the volcanic eruption and explained the genesis of the associated massive sulfide ores.By the end of the article, the Greenstone Formation was compared with the greenstone belts in other parts of the world and the conclusion is that although there are many similarities between them, yet the Liaoning Greenstone Formation is characterized by a higher degree in metamorphism and a richer content of the calc-alkaline volcanic reck series. At last a simple picture of the evolution of the Archaean crust in this district was outlined.