Geological and Biological Reasons for the Cessation of Reef Formation: Evidence from the Paleozoic

The Paleozoic reef formation was a cyclic process, and its global-scale cessation was related to biological reasons: biotic crises and large-scale extinctions near the Early-Middle Cambrian, Ordovician-Silurian, Frasnian-Famennian, Serpukhovian-Bashkirian, and Permian-Triassic boundaries. The Early Cambrian stage of reef formation terminated simultaneously with the disappearance of Archaeocyatha. At the subsequent stages marked by much more complicated ecosystems, the reefs ceased to grow before the complete extinction of reef-builder communities. Hiatuses in the reef formation within separate stages were related to the geological and paleogeographical reasons (manifestations of volcanism, regressions, climate aridization, and others).