Table of Contents
For Students
Quizzes
Read Next
The recorded history of the Precambrian, which covers more than 80 percent of Earth’s geologic history, is divided into two eons: the Archean, between roughly 4 and 2.5 billion years ago, and the Proterozoic, between 2.5 billion and 541 million years ago. In Asia rocks of Archean age are found in the Angaran and Indian platforms, in the North China and the Yangtze paraplatforms, and in smaller fragments caught up in younger orogenic belts such as the North Tarim fragment. In all those places especially, the early Archean evolution was dominated by intrusions of granodiorite that largely represented subduction-related magmatism ...(100 of 38030 words)