Carbonate accumulation in connection with the evolution of bioorganisms inthe Phanerozoic

Marine and oceanic carbonate accumulation in the Vendian-Cambrian was a bio chemogenic process, i.e., was caused mainly by the vital activity of organi sms that formed a geochemical environment favoring carbonate sedimentation. In the early Paleozoic, this process became completely biogenic. Later on, till the end of the Paleozoic, carbonates accumulated mainly in vast shelf seas, and In the Mesozoic, In ocean shoals, reefs, and pelagic zones. In t he Cenozoic, pelagic zones and, to a lesser extent, reefs became the main a ccumulators of carbonates. It is shown that the carbonate accumulation proc ess depended on the atmosphere composition.