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

• Main Author: Flower, Benjamin P
• Format: Dataset
• Language: English
• Published: PANGAEA 1997
• Subjects: Depth, top/min; Depth, bottom/max; Sample code/label; Strontium-87/Strontium-86 ratio; Drilling/drill rig; DSDP/ODP/IODP sample designation; Isotope ratio mass spectrometry; Leg151; Joides Resolution; Ocean Drilling Program ODP; Arctic Ocean; Barents Sea; Foraminifera*; Ice Sheet; Neogloboquadrina pachyderma; Sea ice; Svalbard; Yermak plateau
• Online Access: https://dx.doi.org/10.1594/pangaea.712046; https://doi.pangaea.de/10.1594/PANGAEA.712046

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 ... : Values normalized to NBS987 (National Bureau of Standards) value of 0.710248. ...