Testing the stratigraphic consistency of Pleistocene microfossil bioevents identified on the Alpha and Lomonosov Ridges, Arctic Ocean

Two different biostratigraphic approaches are used to identify Marine Isotope Stage 11 (MIS 11) in Arctic Ocean sediments. On the Lomonosov Ridge, globally calibrated nannofossil bioevents constrain the age of sediments back to MIS 13 (Core LOMROG12-3PC). In the Amerasian Basin the unique occurrence...

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Bibliographic Details
Published in:Arctic, Antarctic, and Alpine Research
Main Authors: Flor Vermassen, Matt O’Regan, Gabriel West, Thomas M. Cronin, Helen K. Coxall
Format: Article in Journal/Newspaper
Language:English
Published: Taylor & Francis Group 2021
Subjects:
arctic
biostratigraphy
foraminifera
geochronology
paleoceanography
Environmental sciences
GE1-350
Ecology
QH540-549.5
Arctic
Arctic Ocean
Alpha Ridge
alpha ridge
Antarctic and Alpine Research
Foraminifera*
Lomonosov Ridge
Online Access:https://doi.org/10.1080/15230430.2021.1988356
https://doaj.org/article/ba3ae28ed17b417ea07094707f154429
Description
Summary:Two different biostratigraphic approaches are used to identify Marine Isotope Stage 11 (MIS 11) in Arctic Ocean sediments. On the Lomonosov Ridge, globally calibrated nannofossil bioevents constrain the age of sediments back to MIS 13 (Core LOMROG12-3PC). In the Amerasian Basin the unique occurrence of the planktonic foraminifer Turborotalita egelida is increasingly used as a marker for MIS 11. However, the T. egelida horizon has only been dated using cyclostratigraphy. Here we bridge these approaches through investigation of a new core (AO16-8GC) from the Alpha Ridge, Amerasian Basin. AO16-8GC is easily correlated to LOMROG12-3PC and contains the T. egelida horizon, allowing the first comparison between the biostratigraphy of both regions. Based on the nannofossil biochronology of LOMROG12-3PC, the most convincing lithologic correlation between the Alpha and Lomonosov Ridge cores places the T. egelida horizon between MIS 15 and MIS 17. This potentially older age for the T. egelida biohorizon emphasizes the need for continued caution in interpreting paleoceanographic records predating MIS 6, until further work can reconcile the nanno- and microfossil biostratigraphies that are emerging for middle Pleistocene sediments of the central Arctic Ocean.

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