Reef Formation during Mass Extinction Events: Frasnian—Famennian and Devonian—Carboniferous Boundaries

Abstract

An analysis of the development of Late Devonian reefs in a number of regions worldwide shows that reef formation decreased gradually and discontinuously during the second half of the Frasnian and was completely terminated in some places. These events were associated with regression stages. The final Frasnian regression and Kellwasser event, which led to the biotic crisis, resulted, first, in the quantitative reduction of reef formation in the Famennian and, second, in the change of the frame reef formation by the formation of microbial mud mounds in the Famennian.