Carbonate Deposition, Climate Stability, and Neoproterozoic Ice Ages

• Published in: Science
• Main Authors: Ridgwell, Andy J., Kennedy, Martin J., Caldeira, Ken
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2003
• Subjects: Ice Sheet
• Online Access: http://dx.doi.org/10.1126/science.1088342; https://www.science.org/doi/pdf/10.1126/science.1088342

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 CO 2 -climate feedback on ice-sheet growth.