The evolution of the atlantic mega-undation

Mega-Undations: A New Model for the Earth's Evolution

“…This type of oceanization is the result of "penetrative convection", of the upper mantle, as defined by MacDonald (1965, p.225); whereas the Atlantic type of oceanization might be interpreted as gravity flow of the outer layers due to "mega-convection" in the entire mantle. The mechanism of this mega-convection might more or less conform to the ideas put forward by Bernal (1961), Orowan (1965), and Van Bemmelen (1964b. A major riddle still is the origin of the Pacific Ocean.…”

“…In the preceding papers on mega-undations (Van Bemmelen, 1964b) the author came to the conclusion, based largely on geotectonic evidence, that the Atlantic and the Indian Ocean Mega-Undations both started in PermoTriassic time, in an area situated somewhere southeast of South Africa (see Fig.6). The &-and q-centres were situated in the neighbourhood of Wegener's South Pole for Late Carboniferous time.…”

“…Nevertheless the diagnositic geological facts are too solid to deny them. The depth of the Moho discontinuity is not a permanent feature (Van Bemmelen, 1958, 1964b. Kushiro and Yoder (1964) draw attention to the fact that the density change of the basalt (or gabbro) -eclogite transformation is gradual.…”

“…It has been elaborated in two papers, the first of which (Van Bemmelen, 1964b) analysed in more detail the evolution of the Atlantic Mega-Undation, and the second one (Van Bemmelen, 1965a) treated the Indian Ocean Mega-Undation. The present paper is the third part of this series.…”