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1.有关绿岩带的早期和现代的概念认识太古代浅变质岩系的原始火山岩和沉积岩,以及其地球化学特征,是有关早期地壳演化模式方面的资料积累的结果。在采用同位素年令资料以前,对前寒武纪的研究都习惯地采用推断的方法,例如认为变质程度越深表明地质年令越老,或者认为地壳在某一个阶段里完全是重复循环的,或者认为地球第一次冷却后,就形成了世界规模的硅铝层等等。然而广泛推断至今仍然存在着的前寒武纪的变质火山岩套,已有部分被显生宙造山岩带的相似物质给淹没了。例如认为前寒武纪省代表着一系列的大造山旋廻,虽
1. The Early and Modern Concepts of Green Belt Understanding the primitive volcanic and sedimentary rocks of the Archean shallow metamorphic rocks and their geochemical characteristics are the result of accumulation of data on the evolutionary patterns of the early crust. Prior to the use of isotopic dating data, studies of the Precambrian used customary inferences, such as the assumption that the deeper the degree of metamorphism is, the older the geologic age is, or that the crust is completely recirculated at some stage, Or think the world after the first cooling, it formed a world-scale silicon aluminum layer and so on. However, it is widely assumed that Precambrian metamorphic volcanic rocks still exist to some extent submerged by similar materials from the Phanerozoic orogenic belts. For example, the Precambrian province is considered a series of major structural revolutions, though