Pliocene/Pleistocene benthic foraminiferal abundances from six drilling cores

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Main Authors: Hayward, Bruce William, Kawagata, Shungo, Grenfell, Hugh R, Sabaa, Ashwaq T, O'Neill, Tanya
Format: Dataset Open Access
Language:en
Published: PANGAEA 2007
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author Hayward, Bruce William
Kawagata, Shungo
Grenfell, Hugh R
Sabaa, Ashwaq T
O'Neill, Tanya
author_facet Hayward, Bruce William
Kawagata, Shungo
Grenfell, Hugh R
Sabaa, Ashwaq T
O'Neill, Tanya
collection Datos científicos de ciencias marinas y ambientales
contents Twenty percent (19 genera, 95 species) of cosmopolitan, deep-sea (500-4000 m), benthic foraminiferal species became extinct during the late Pliocene-Middle Pleistocene (3-0.12 Ma), with the peak of extinctions (76 species) occurring during the mid-Pleistocene Climate Transition (MPT, 1.2-0.55 Ma). One whole family (Stilostomellidae, 30 species) was wiped out, and a second (Pleurostomellidae, 29 species) was decimated with just one species possibly surviving through to the present. Our studies at 21 deep-sea core sites show widespread pulsed declines in abundance and diversity of the extinction group species during more extreme glacials, with partial interglacial recoveries. These declines started in the late Pliocene in southern sourced deep water masses (Antarctic Bottom Water, Circumpolar Deep Water) and extending into intermediate waters (Antarctic Intermediate Water, North Atlantic Deep Water) in the MPT, with the youngest declines in sites farthest downstream from high-latitude source areas for intermediate waters. We infer that the unusual apertural types that were targeted by this extinction period were adaptations for a specific kind of food source and that it was probably the demise of this microbial food that resulted in the foraminiferal extinctions. We hypothesize that it may have been increased cold and oxygenation of the southern sourced deep water masses that impacted on this deep water microbial food source during major late Pliocene and Early Pleistocene glacials when Antarctic ice was substantially expanded. The food source in intermediate water was not impacted until major glacials in the MPT when there were significant expansion of polar sea ice in both hemispheres and major changes in the source areas, temperature, and oxygenation of global intermediate waters.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_746497
institution PANGAEA
language en
publishDate 2007
publisher PANGAEA
record_format pangaea
spellingShingle Pliocene/Pleistocene benthic foraminiferal abundances from six drilling cores
Hayward, Bruce William
Kawagata, Shungo
Grenfell, Hugh R
Sabaa, Ashwaq T
O'Neill, Tanya
160-966B; 161-975D; 161-976C; 167-1012B; 172-1055B; Alboran Sea; Carolina Slope, North Atlantic Ocean; DRILL; Drilling/drill rig; Eastern Basin; Joides Resolution; KR9912PC4; Leg160; Leg161; Leg167; Leg172; North Pacific Ocean; Ocean Drilling Program; ODP; South Pacific Ocean; Western Basin
Twenty percent (19 genera, 95 species) of cosmopolitan, deep-sea (500-4000 m), benthic foraminiferal species became extinct during the late Pliocene-Middle Pleistocene (3-0.12 Ma), with the peak of extinctions (76 species) occurring during the mid-Pleistocene Climate Transition (MPT, 1.2-0.55 Ma). One whole family (Stilostomellidae, 30 species) was wiped out, and a second (Pleurostomellidae, 29 species) was decimated with just one species possibly surviving through to the present. Our studies at 21 deep-sea core sites show widespread pulsed declines in abundance and diversity of the extinction group species during more extreme glacials, with partial interglacial recoveries. These declines started in the late Pliocene in southern sourced deep water masses (Antarctic Bottom Water, Circumpolar Deep Water) and extending into intermediate waters (Antarctic Intermediate Water, North Atlantic Deep Water) in the MPT, with the youngest declines in sites farthest downstream from high-latitude source areas for intermediate waters. We infer that the unusual apertural types that were targeted by this extinction period were adaptations for a specific kind of food source and that it was probably the demise of this microbial food that resulted in the foraminiferal extinctions. We hypothesize that it may have been increased cold and oxygenation of the southern sourced deep water masses that impacted on this deep water microbial food source during major late Pliocene and Early Pleistocene glacials when Antarctic ice was substantially expanded. The food source in intermediate water was not impacted until major glacials in the MPT when there were significant expansion of polar sea ice in both hemispheres and major changes in the source areas, temperature, and oxygenation of global intermediate waters.
title Pliocene/Pleistocene benthic foraminiferal abundances from six drilling cores
topic 160-966B; 161-975D; 161-976C; 167-1012B; 172-1055B; Alboran Sea; Carolina Slope, North Atlantic Ocean; DRILL; Drilling/drill rig; Eastern Basin; Joides Resolution; KR9912PC4; Leg160; Leg161; Leg167; Leg172; North Pacific Ocean; Ocean Drilling Program; ODP; South Pacific Ocean; Western Basin
url https://doi.org/10.1594/PANGAEA.746497