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On the Origin of Continents and Ocean Floors
J. H. F. Umbgrove
The Journal of Geology
Vol. 54, No. 3 (May, 1946), pp. 169-178
Published by: The University of Chicago Press
Stable URL: http://www.jstor.org/stable/30057157
Page Count: 10
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From the concept of permanence the fundamental question arises as to how the distribution of continental and oceanic sectors came into being. Three groups of theories are discussed: (1) theories starting with a primary surface layer of basaltic composition; (2) theories starting with the resonance theory of the moon's origin and considering the result of such a hypothetical happening on a sialic surface layer of continental thickness; and (3) theories considering the influence of convection currents on a surface layer of sialic composition.
The Journal of Geology © 1946 The University of Chicago Press