(Table 1) Strontium isotope ratios (87Sr/86Sr) of Neogloboquadrina pachyderma (sinistrally coiling) tests from ODP Hole 151-910A

The sediment sequence at Ocean Drilling Program (ODP) Site 910 (556 m water depth) on the Yermak Plateau in the Arctic Ocean features a remarkable "overconsolidated section" from ~19 to 70-95 m below sea floor (m bsf), marked by large increases in bulk density and sediment strength. The OD...

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Bibliographic Details
Main Author: Flower, Benjamin P
Format: Dataset
Language:English
Published: PANGAEA - Data Publisher for Earth & Environmental Science 1997
Subjects:
Depth, top/min
Depth, bottom/max
Sample code/label
Strontium-87/Strontium-86
Drilling/drill rig
DSDP/ODP/IODP sample designation
Isotope ratio mass spectrometry
Leg151
Joides Resolution
Ocean Drilling Program ODP
Arctic
Arctic Ocean
Svalbard
Barents Sea
Yermak Plateau
Foraminifera*
Ice Sheet
Ice Shelf
Neogloboquadrina pachyderma
Sea ice
Yermak plateau
Online Access:https://dx.doi.org/10.1594/pangaea.712046
https://doi.pangaea.de/10.1594/PANGAEA.712046
Description
Summary:The sediment sequence at Ocean Drilling Program (ODP) Site 910 (556 m water depth) on the Yermak Plateau in the Arctic Ocean features a remarkable "overconsolidated section" from ~19 to 70-95 m below sea floor (m bsf), marked by large increases in bulk density and sediment strength. The ODP Leg 151 Shipboard Scientific Party interpreted the overconsolidated section to be caused by (1) grounding of a marine-based ice sheet, derived from Svalbard and perhaps the Barents Sea ice sheet, and/or (2) coarser-grained glacial sedimentation, which allowed increased compaction. Here I present planktonic foraminiferal d18O data based on Neogloboquadrina pachyderma (sinistrally coiling) that date the termination of overconsolidation near the boundary between isotope stages 16 and 17 (ca. 660 ka). No evidence is found for coarser grained sedimentation, because lithic fragments >150 µm exhibit similar mean concentrations throughout the upper 24.5 m bsf. The overconsolidated section may reflect more extensive ice-sheet grounding prior to ca. 660 ka, suggesting a major change in state of the Svalbard ice sheets during the mid-Quaternary. Furthermore, continuous sedimentation since that time argues against a pervasive Arctic ice shelf impinged on the Yermak Plateau during the past 660 k.y. These findings suggest that Svalbard ice-sheet history was largely independent of circum-Arctic ice-sheet history during the middle to late Quaternary. : Values normalized to NBS987 (National Bureau of Standards) value of 0.710248.

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