Bioinduced crustification as a reaction of Late Carboniferous-Early Permian reef ecosystems to biosphere changes

Abstract

Synsedimentary crustification cements played an important role in the formation of Upper Carboniferous-Lower Permian skeletal mounds in the North Urals. In reef ecosystems, small or thin organisms covered with biofilms served as a substrate for hard cement crusts. Probably free-living sessile organisms couldn’t form frame constructions. However extensive, rapid posthumous biologically induced crustification of soft skeletons of organisms deposited over heterogeneous bioclastic material facilitates development of prominent hard frameworks on the sea-bottom in the slope environment.