Planktonic foraminiferal assemblages of the Paleocene-Eocene Thermal Maximum of ODP Hole 113-690B

• Main Author: Kelly, Daniel Clay
• Format: Dataset
• Language: English
• Published: PANGAEA 2002
• Subjects: 113-690B; Acarinina coalingensis; Acarinina mckannai; Acarinina nitida; Acarinina praepentacamerata; Acarinina soldadoensis; Acarinina spp.; Acarinina subsphaerica; Alabamina wilcoxensis; Chiloguembelina trinitatensis; Counting >180 µm fraction; DEPTH; sediment/rock; DRILL; Drilling/drill rig; Foraminifera; planktic; Globanomalina australiformis; Joides Resolution; Leg113; Morozovella spp.; Ocean Drilling Program; ODP; Parasubbotina varianta; South Atlantic Ocean; Subbotina patagonica; Subbotina spp; Antarctic; Weddell Sea; Weddell; Antarc*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.842889; https://doi.org/10.1594/PANGAEA.842889

High-resolution study of Antarctic planktonic foraminiferal assemblages (Ocean Drilling Program Site 690, Weddell Sea) shows that these microplankton underwent a stepwise series of changes during the Paleocene–Eocene thermal maximum (PETM). Initiation of this response coincides with the onset of the carbon isotope excursion (CIE) but precedes the benthic foraminiferal mass extinction. The “top-to-bottom” succession in the biotic response indicates that the surface ocean/atmosphere was affected before the deep sea. The earliest stage of the faunal response entailed a conspicuous turnover within the shallow-dwelling genus Acarinina and a succession of stratigraphic first appearances. The genus Morozovella, large (>180 µm) biserial planktonics, and A. wilcoxensis are all restricted to the lower CIE within this PETM section. Acarininid populations crashed as the ocean/climate system ameliorated during the CIE recovery, reflecting atypical surface water conditions. This transient decline in acarininids is paralleled by a marked increase in carbonate content of sediments. It is postulated that this interval of carbonate enrichment, and its unusual microfauna, reflects enhanced carbon storage within reservoirs of the global carbon cycle other than the marine carbonate system (sensu Broecker et al., 1993, doi:10.1029/93PA00423; Ravizza et al., 2001, doi:10.1029/2000PA000541).