Phanerozoic transgressions and regressions on the continents: a quantitative approach based on areas flooded by the sea and areas of marine and continental deposition

Abstract

Analysis of the areas of major tectonic units of the continents flooded by the sea during the Phanerozoic shows that there have been three major cycles of transgression and regression corresponding to the Caledonian, Hercynian, and Alpine orogenic cycles. Approximately equal areas of the platforms and geosynclinal regions have been flooded synchronously, but seas occupied only small aras of the orogenic belts. In terms of proportions of the area flooded, the platform regions average about 20%, the geosynclinal regions about 80%, and the orogenic belts about 20% in the Palaeozoic, and 10% in the Mesozoic and Cenozoic. There has been a decline in the proportion of the area of marine versus continental sedimentation throughout the Phanerozoic on the continental platforms and in orogenic belts. A similar decline has occurred in the geosynclinal regions but only during the later Mesozoic and Cenozoic. -from Author