Journal of Petroleum Geology, Vol.9, No.2, pp. 207-216, 1986

©Copyright 2000 Scientific Press, Ltd.

THE EVOLUTION OF OCEAN BASINS DURING CENOZOIC TIME

V. V. Orlenok*

* USSR Academy of Sciences, Kaliningrad State University, Kaliningrad, USSR.

Abstract

Evidence has accumulated steadily during recent years to show that ocean basins are quite young, certainly younger than Paleozoic and PreCambrian. The most common mechanism invoked to explain the relatively youthful age of ocean basins is through sea-floor spreading, i.e. by the theory of plate-tectonics; however, the Author believes that it can be explained more logically by a process of "oceanization", for which clear evidence was shown in 149 of the first 493 DSDP+ boreholes. The oceans began to form during the Middle Jurassic (the oldest marine strata penetrated in the boreholes), about 170 MM years++ ago. Beginning in the Paleogene, the oceans began to deepen more rapidly. This deepening was accompanied by the effusion of great thicknesses of plateau basalt. The sinking process was made possible by the thickening of the asthenosphere beneath the ocean basins, a process which is continuing towards the continents as these become "oceanized". It is to be expected that the entire process will be completed within the next 30 to 50 MM years.