Oxygen and Carbon Isotopes in Marine Carbonates: A Biogenic Climate Archive Built Upon Disequilibria

The stable isotopic composition of marine biogenic carbonates is one of the main archives for paleoclimate reconstructions. Reading these archives accurately requires understanding of how different organisms make carbonate minerals, and how various biomineralization processes influence stable isotope fractionation. New developments in stable isotope measurements, laboratory experiments, and biomineralization modeling have progressively enabled us to disentangle the environmental and biological controls on the stable isotope proxies, and offer promise for a deeper understanding of how calcifying organisms record and respond to changes in Earth’s climate and carbon cycle through geologic time.