O'Regan, Matthew et al. (2010): Glacial geological implications of overconsolidated sediments on the Lomonosov Ridge and Yermak Plateau

Leg/Site/Hole:
ODP 151
ODP 151 910
Identifier:
2012-053028
georefid

10.1016/j.quascirev.2010.09.009
doi

Creator:
O'Regan, Matthew
Stockholm University, Department of Geological Sciences, Stockholm, Sweden
author

Jakobsson, Martin
author

Kirchner, Nina
author

Identification:
Glacial geological implications of overconsolidated sediments on the Lomonosov Ridge and Yermak Plateau
2010
In: Jakobsson, Martin (editor), Ingolfsson, Olafur (editor), Kjaer, Kurt H. (editor), Long, Antony (editor), Spielhagen, Robert F. (editor), APEX; Arctic Palaeoclimate and its EXtremes
Elsevier, International
29
25-26
3532-3544
With the coupled use of multibeam swath bathymetry, high-resolution subbottom profiling and sediment coring from icebreakers in the Arctic Ocean, there is a growing awareness of the prevalence of Quaternary ice-grounding events on many of the topographic highs found in present water depths of <1000 m. In some regions, such as the Lomonosov Ridge and Yermak Plateau, overconsolidated sediments sampled through either drilling or coring are found beneath seismically imaged unconformities of glacigenic origin. However, there exists no comprehensive analysis of the geotechnical properties of these sediments, or how their inferred stress state may be related to different glacigenic processes or types of ice-loading. Here we combine geophysical, stratigraphic and geotechnical measurements from the Lomonosov Ridge and Yermak Plateau and discuss the glacial geological implications of overconsolidated sediments. The degree of overconsolidation, determined from measurements of porosity and shear strength, is shown to result from consolidation and/or deformation below grounded ice and, with the exception of a single region on the Lomonosov Ridge, cannot be explained by erosion of overlying sediments. We demonstrate that the amount and depth of porosity loss associated with a middle Quaternary ( approximately 790-950 thousand years ago - ka) grounding on the Yermak Plateau is compatible with sediment consolidation under an ice sheet or ice rise. Conversely, geotechnical properties of sediments from beneath late Quaternary ice-groundings in both regions, independently dated to Marine Isotope Stage (MIS) 6, indicate a more transient event commensurate with a passing tabular iceberg calved from an ice shelf. Abstract Copyright (2010) Elsevier, B.V.
English
Serial
Coverage:Geographic coordinates:
North:82.4000
West:0.0000East: 12.3000
South:79.3000

Quaternary geology; Sedimentary petrology; acoustical methods; Arctic Ocean; bathymetry; Cenozoic; compaction; consolidation; diagenesis; geophysical methods; geophysical surveys; glacial geology; ice; Leg 151; Lomonosov Ridge; marine methods; marine sediments; Ocean Drilling Program; ODP Site 910; physical properties; porosity; Quaternary; sea ice; sedimentology; sediments; shear strength; surveys; Yermak Plateau;

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