Introduction: Plate Tectonics and Geology

Abstract

Plate tectonics, as it operates in the modern earth, represents in a fundamental sense a mechanism by which excess thermal energy from the mantle is dissipated (Sclater et al. 1980). Substantial evidence now exists for the operation of plate tectonics during Phanerozoic time, and evidence for similar tectonic activity during Proterozoic time is steadily growing, both in quantity and quality (Hoffman 1988). Furthermore, concrete evidence for the operation of essentially analogous forms of plate tectonics during Archean time is now appearing (Condie 1982; Helmstaedt et al. 1986) supporting the notion that the provocative similarities that exist between certain elements of Archean terranes and plate boundary-related terranes of late Phanerozoic age can be reasonably interpreted in terms of uniformitarianism.