Hayward, Bruce W.; Grenfell, Hugh R.; Sabaa, Ashwaq T.; Sikes, Elizabeth (2005): Deep-sea benthic foraminiferal record of the mid-Pleistocene transition in the SW Pacific. Geological Society of London, London, United Kingdom, In: Head, Martin J. (editor), Gibbard, Philip L. (editor), Early-middle Pleistocene transitions; the land-ocean evidence, 247, 85-115, georefid:2006-031596

Benthic foraminiferal faunas from three bathyal sequences provide a proxy record of oceanographic changes through the mid-Pleistocene transition (MPT) on either side of the Subtropical Front (STF), east of New Zealand. Canonical correspondence analyses show that factors related to water depth, latitude and climate cycles were more significant than oceanographic factors in determining changes in faunal assemblage composition over the last 1 Ma. Even so, mid-Pleistocene faunal changes are recognizable and can be linked to inferred palaeoceanographic causes. North of the largely stationary STF the faunas were less variable than to the south, perhaps reflecting the less extreme glacial-interglacial fluctuations in the overlying Substropical Surface Water. Prior to Marine Isotope Stage (MIS) 21 and after MIS 15, the northern faunas had fairly constant composition, but during most of the MPT faunal composition fluctuated in response to climate-related food-supply variations. Faunal changes through the MPT suggest increasing food supply and decreasing dissolved bottom oxygen. South of the STF, beneath Subantarctic Surface Water, mid-Pleistocene faunas exhibited strong glacial-interglacial fluctuations, inferred to be due to higher interglacial nutrient supply and lower oxygen levels. The most dramatic faunal change in the south occurred at the end of the MPT (MIS 15-12), with an acme of Abditodentrix pseudothalmanni, possibly reflecting higher carbon flux and lowered bottom oxygen. This study suggests that the mid-Pleistocene decline and extinction of a group of elongate, cylindrical deep-sea foraminifera may have been related to decreased bottom oxygen concentrations as a result of slower deep-water currents.
West: -178.0959 East: 174.5653 North: -42.3259 South: -45.3129
Expedition: 181
Site: 181-1119
Site: 181-1125
Expedition: 90
Site: 90-594
Supplemental Information:
Includes appendices
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Provider: SEDIS Publication Catalogue
Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=2006-031596 (c.f. for more detailed metadata)
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