Petrologic data from Site U1308 over the last three glaciations ...

A composite North Atlantic record from DSDP Site 609 and IODP Site U1308 spans the past 300,000 years and shows that variability within the penultimate glaciation differed substantially from that of the surrounding two glaciations. Hematite stained grains exhibit similar repetitive down-core variati...

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Bibliographic Details
Main Authors: Obrochta, Stephen P, Crowley, Thomas J, Channell, James E T, Hodell, David A, Baker, Paul A, Seki, Arisa, Yokoyama, Yusuke
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA 2014
Subjects:
Integrated Ocean Drilling Program / International Ocean Discovery Program IODP
Antarctic
Hudson
Hudson Strait
Antarc*
Ice Sheet
North Atlantic
Sea ice
Online Access:https://dx.doi.org/10.1594/pangaea.834640
https://doi.pangaea.de/10.1594/PANGAEA.834640
Description
Summary:A composite North Atlantic record from DSDP Site 609 and IODP Site U1308 spans the past 300,000 years and shows that variability within the penultimate glaciation differed substantially from that of the surrounding two glaciations. Hematite stained grains exhibit similar repetitive down-core variations within the Marine Isotope Stage (MIS) 8 and 4-2 intervals, but little cyclic variability within the MIS 6 section. There is also no petrologic evidence, in terms of detrital carbonate-rich (Heinrich) layers, for surging of the Laurentide Ice Sheet through the Hudson Strait during MIS 6. Rather, very high background concentration of ice-rafted debris (IRD) indicates near continuous glacial meltwater input that likely increased thermohaline disruption sensitivity to relatively weak forcing events, such as expanded sea ice over deepwater formation sites. Altered (sub)tropical precipitation patterns and Antarctic warming during high orbital precession and low 65° N summer insolation appears related to high ... : For data in MIS4-2 of DSDP Site 94-609 see Obrochta et al. (2012). ...

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