What controlled the thickness of continental crust in the Archean?

Abstract

Abstract Exposed continents are one of Earth's major characteristics. Recent studies on ancient ocean volume and exposed landmasses suggest, however, that early Earth was possibly a water world, where any significant landmass was unlikely to have risen above sea level. On modern Earth, the thickness of continental crust seems to be controlled by sea level and the buoyancy of continental crust. Simply applying this concept to the Archean would not explain the absence of exposed continents, and we suggest that a third element that is currently insignificant was important during early Earth: the strength of continental upper crust. Based on the pressure imbalance expected at continent-ocean boundaries, we quantified the conditions under which rock strength controls the thickness of continental crust. With the level of radiogenic heat production expected for early Earth, continents may have been too weak to have maintained their thickness against a deep ocean.