Studies on the Evolution of Sedimentary Rock Formation As a Clue to the Solution of Several General Geological Problems

Abstract

Studies on the distribution of detrital rocks, reefs, and sand-to-clay rock ratios show that geological history has witnessed the gradual differentiation between subaqueous and subaerial reliefs. An increase in the height of mountains was possible due to the immersion of the asthenospheric layer and the increase in the thickness of the continental crust in general and especially in folding areas. This led to the gradual strengthening of relief contrasts and the growth of trough depths in subduction zones. A historical change in the composition of carbonate rocks, the replacement of Archean and Lower Proterozoic limestones and siderites with dolomites and magnesites in the Middle and Upper Proterozoic and then the successive displacement of the latter by limestones in the Phanerozoic suggests a change in the acid–alkali regime of water basins and a transfer from the Archean acid basins to alkali basins in the Proterozoic and partly early Paleozoic and then to neutral and weakly alkali basins in the rest of the Phanerozoic.