Glacial geological implications of overconsolidated sediments on the Lomonosov Ridge and Yermak Plateau
2010 (English)In: Quaternary Science Reviews, ISSN 0277-3791, Vol. 29, no 25-26, 3532-3544 p.Article in journal (Refereed) Published
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 (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.
Place, publisher, year, edition, pages
2010. Vol. 29, no 25-26, 3532-3544 p.
Glaciology, ice sheets, Arctic Ocean
Earth and Related Environmental Sciences
Research subject Geology
IdentifiersURN: urn:nbn:se:su:diva-47303DOI: 10.1016/j.quascirev.2010.09.009ISI: 000284724400014OAI: oai:DiVA.org:su-47303DiVA: diva2:373558