The Impact of the Latest Danian Event on Planktic Foraminiferal Faunas at ODP Site 1210 (Shatsky Rise, Pacific Ocean).

Abstract

The marine ecosystem has been severely disturbed by several transient paleoenvironmental events (0.6‰, similar in magnitude to the one previously reported from neighboring Site 1209 for benthic foraminifera. δ18O-inferred warming by 1.6 to 2.8°C (0.4-0.7‰ δ18O measured on benthic and planktic foraminiferal tests) of the entire water column accompanies the negative δ13C excursion. A well stratified upper ocean directly before and during the LDE is proposed based on the stable isotope gradients between surface and subsurface dwellers. The gradient is less well developed, but still enhanced after the event. Isotope data are supplemented by comprehensive planktic foraminiferal faunal analyses revealing a dominance of Morozovella species together with Parasubbotina species. Subsurface-dwelling Parasubbotina shows high abundances during the LDE tracing changes in the strength of the isotope gradients and, thus, may indicate optimal living conditions within a well stratified surface ocean for this taxon. In addition, distinct faunal changes are reported like the disappearance of Praemurica species right at the base of the LDE and the continuous replacement of M. praeangulata with M. angulata across the LDE.