Understanding Climate Change and Ocean Acidification before and using the End Cretaceous Extinction by using calcium isotopes from Mollusc shells.
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Debate persists about the causes of the Cretaceous-Paleogene mass extinction. The bolide impact at Chicxulub left a globally distributed iridium anomaly at the primary extinction horizon that is coincident with the rapid extinction of both terrestrial and marine organisms. However, some experts propose that eruption of the Deccan Traps Large Igneous Province caused the extinction. Although Large Igneous Province volcanism commonly correspond with mass extinctions, questions remain about the link between Deccan volcanism and the Cretaceous-Paleogene extinction Ocean Acidification which encompasses transient decreases in pH, and carbonate mineral saturation states resulting from the large and rapid injection of CO₂, into the atmosphere-ocean system, may have caused extinctions throughout Earth history. The Deccan Traps volcanism released large quantities of CO₂, which likely caused warming and Ocean Acidification on a Global scale. Sedimentological indicators, such as reduced carbonate weight percent and increased planktic Foraminiferal fragmentation, suggest eruption of the Deccan Traps forced Ocean Acidification before the Cretaceous-Paleogene boundary. The bolide impact may have caused lesser and transient Ocean Acidification. During and following Ocean Acidification, dissolution of seafloor carbonate and biological compensation restore balance by neutralizing acidity and elevating alkalinity. Over longer time scales, silicate weathering plays a similar role.