Pronounced biotic and environmental change across the latest Danian warming event (LDE) at Shatsky Rise, Pacific Ocean (ODP Site 1210)

Abstract

Abstract The early Paleogene is characterized by numerous hyperthermals, transient ( Nuttallides umbonifera dominated assemblage. Yet, ~ 200 kyr before the LDE, benthic foraminiferal assemblages, with increased relative abundance of endobenthic morphotypes and benthic foraminiferal accumulation rates indicate a slightly enhanced food flux. A temperature increase ~ 40 kyr before the first carbon isotope excursion (CIE) of the LDE (= LDE1) is associated with a rise in abundance of Tappanina selmensis , suggesting episodic input of fresh phytodetritus. At the start of LDE1, and through the second CIE (= LDE2), the seafloor returned to more oligotrophic conditions. Between 220 and 430 kyr after the onset of the LDE, a second phase of episodic fresh phytodetritus input is suggested by a renewed dominance of T. selmensis . Although the patterns of faunal change during hyperthermals relate to local conditions (circulation patterns), the magnitude of faunal change is probably more related to an absolute temperature threshold.