Carbonate deposition, climate stability, and Neoproterozoic ice ages.
The evolutionary success of planktic calcifiers during the Phanerozoic stabilized the climate system by introducing a new mechanism that acts to buffer ocean carbonate-ion concentration: the saturation-dependent preservation of carbonate in sea-floor sediments. Before this, buffering was primarily accomplished by adjustment of shallow-water carbonate deposition to balance oceanic inputs from weathering on land. Neoproterozoic ice ages of near-global extent and multimillion-year duration and the formation of distinctive sedimentary (cap) carbonates can thus be understood in terms of the greater sensitivity of the Precambrian carbon cycle to the loss of shallow-water environments and CO2-climate feedback on ice-sheet growth.
Ridgwell
Andy J
AJ
Department of Earth Sciences, University of California-Riverside, Riverside, CA 92521, USA. andyr@citrus.ucr.edu
Kennedy
Martin J
MJ
Caldeira
Ken
K