The Paleocene-Eocene Thermal Maximum (PETM, 56 million years ago) is an important paleoclimate event used to understand how Earth’s climate system responded to rapid increases in atmospheric methane and carbon dioxide. One approach to study this interval is chemical analysis of microfossils known as foraminifera preserved in deep-sea sediment. Foraminifera grow calcium carbonate shells that record the environmental conditions of the organism’s habitat. However, PETM foraminiferal records suffer from two well-known limitations: first, ocean acidification at the PETM onset can lead to the dissolution of the carbonate shells and, second, vertical sediment mixing (bioturbation) can intermingle shells from different time periods together. Until recently, vertical mixing was a significant drawback because analyses required multiple shells to have sufficient accuracy. This project will remedy those issues by constructing records of individual foraminiferal geochemistry and morphology across the PETM at International Ocean Discovery Program (IODP) Site U1580 located on the Agulhas Plateau in the Southern Ocean. Site U1580 features abundant microfossils that were not dissolved. Cutting-edge analytical techniques will permit measurements on individual foraminifera to disentangle signals affected by bioturbation. Results will produce new estimates of surface and deep-water warming and carbon cycle dynamics across the PETM onset. The proposed work will support a team of three early caree