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The first 800 million years of earth's historyIt is pointed out that there is no direct geological information on the first 750 Ma of earth history. Consequently the reported study is based on controversial inferences drawn from the moon, other planets and meteorites, coupled with backward extrapolation from surviving terrestrial rocks, especially those of Archaean age. Aspects of accretion are considered, taking into account cosmochemical and cosmophysical evidence, a new earth model, and convection systems. Attention is given to phase-equilibrium constraints, estimates of heat production, the bombardment history of the moon and implications for the earth, and the nature of the early crust. From a combination of physical, chemical, and petrological arguments, it is concluded that the earth's surface underwent intense volcanism in the pre-Archaean era, and that the rock types were chemically similar to those found in the early Archaean era.
Document ID
19810051428
Document Type
Reprint (Version printed in journal)
Authors
Smith, J. V. (Chicago, University Chicago, Ill., United States)
Date Acquired
August 11, 2013
Publication Date
May 15, 1981
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF EAR-77-27100
CONTRACT_GRANT: NGL-14-001-171
Distribution Limits
Public
Copyright
Other