1. The Eras of Geologic Time
... metamorphism. Precambrian rocks often occur in shields, which are large areas of relatively low elevation that form parts of continental masses. One of the largest exposed areas of early Precambrian rocks can be found in Canada and is known as the Canadian Shield. Granite, schist, and gneiss are generally the type of rocks that can be found in the region. The belief that rudimentary life existed ... Paleozoic era and the beginning of the topography of North America. The Mesozoic era marks a major division of geologic time from sixty five to two hundred and twenty five million years ago ...
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- Approx Pages: 7
- Grade Level: Undergraduate