Paleoceanographic changes across the Latest Danian Event in the South Atlantic Ocean and planktic foraminiferal response

The less known "Latest Danian Event" (LDE) at 62.2 Ma represents a 200 ky-lasting warming phase, superimposed on a long-term cooling trend after the Early Paleocene. South Atlantic ODP Site 1262 data, covering ~1 myr, indicate a warming of the entire water column by 1.5-2.6°C, accompanying a prominent negative carbon isotope excursion (~0.9-1.1 ‰) and a long-term re-organization of the planktic foraminiferal fauna associated with the LDE.

This study unravels a different paleoceanographic evolution of the upper ocean structure compared to results from Pacific ODP Site 1210. Unlike the Pacific, the Atlantic site lacks an apparent change of stratification as well as an overall dominance of thermocline dwelling planktic foraminifera species and a low abundance of surface dwelling photosymbiotic foraminifera. Within the LDE, indications for a slightly enhanced stratification of the upper water column and transient warming was indicated when surface dwelling planktic foraminifera became temporarily more abundant.