Fossil biocalcite remains open to isotopic exchange with seawater for tens of millions of years.

ABSTRACT: Fossilized remains of marine calcifiers constitute the physical basis for reconstructions of both deep ocean and sea-surface temperatures going back millions of years, but paleoclimate records derived from their isotope and trace-element chemistry can be biased by diagenesis. Experiments simulating diagenesis in the presence of an ¹⁸O-rich seawater analogue were conducted with modern and 14 Myr old foraminifera (Ammonia sp.) tests to investigate their relative susceptibility to oxygen isotope exchange. The fossilized tests were of exceptional preservation and similar to modern tests in terms of structure and crystalline organization, but had experienced partial loss of embedded organic structures, thus a priori offering fewer preferential pathways for porewaters to penetrate the

SUBMITTER: Cisneros-Lazaro D 

PROVIDER: S-EPMC11496820 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature