Record of Deep-Sea, Benthic Elongate-Cylindrical Foraminifera Across the Eocene-Oligocene Transition in the North Atlantic Ocean (ODP Hole 647A)

摘要: The Eocene-Oligocene transition (EOT) at ∼34 Ma constitutes one of the major episodes climate change that occurred in last 50 myr, associated with establishment permanent Antarctic ice sheets and initiation meridional overturning circulation. We present a high-resolution quantitative study (>125-μm fraction) group calcareous, deep-sea, benthic foraminifera elongate-cylindrical morphologies (Elongate Gp.) across EOT high latitudes North Atlantic Ocean (ODP Hole 647A). This experienced significant declines abundance diversity during periods global cooling, disappearing almost completely mid-Pleistocene Climate Transition. The Elongate Gp. was common component deep-sea foraminiferal assemblages 647A (average 20%). family Stilostomellidae dominated late Eocene EOT; Nodosariidae slightly early Oligocene. During 647A, an abrupt decline agglutinated occurred, but not distinct taxonomic turnover Siphonodosaria jacksonensis most abundant species showed changes relative EOT, from no record to peak >50% total coincident lowest highest absolute attribute these influence more than mechanism, including increased productivity, deepening calcite compensation depth, vigorous deep-ocean