The glacial history of the southern Svartenhuk Halvø, West Greenland

• Published in: arktos
• Main Authors: Lane, Timothy P., Roberts, David H., Ó Cofaigh, Colm, Vieli, Andreas, Moreton, Steven G.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer 2015
• Subjects: Greenland; Svartenhuk; glacier; Ice cap; Ice Sheet; Svartenhuk halvø; Uummannaq
• Online Access: http://eprints.gla.ac.uk/121687/

This paper presents a new, detailed geomorphological and sedimentological appraisal of the southern Svartenhuk Halvø, a remote area of West Greenland that has only been subjected to limited geomorphological and sedimentological research. Despite this, it is of importance as several studies have suggested it remained an ice-free enclave during the Last Glacial Maximum. This previous work, based on biostratigraphic and chronological evidence, has provided evidence for the ‘Svartenhuk Marine Event’, a period of ice free conditions and marine deposition into a higher than present relative sea-level during the previous interglacial (MIS 5a–e). This has been correlated to other interglacial deposits in West Greenland. New geomorphological and sedimentological investigations from this study present compelling arguments for the glaciation of southern Svartenhuk Halvø by valley glaciers and mountain ice caps, questioning the status of this peninsula as an ice-free enclave. Ice directional indicators and clast lithological results suggest ice covering Svartenhuk Halvø was sourced from the higher altitude interior of the peninsula and expanded to the present coastline. In a number of valleys, sedimentological evidence points to at least two glacial advances with subglacial till production through the reworking of glaciomarine sediments, and ice contact and glacier-fed delta deposition during phases of ice retreat. The geomorphological and sedimentological context of the sediments (Gilbert type deltas), coupled with evidence for eskers and kettled/pitted delta surfaces, suggests these features formed under glacial and not interglacial conditions. This is supported by new radiocarbon dates which suggest outlet glacier advance and retreat across the area towards the end of MIS 3 and possibly into the Early Holocene. Svartenhuk Halvø was not overrun by the main Greenland Ice Sheet during the last glacial cycle, but the development of an independent ice cap and local outlet glaciers across this region may have been instrumental in determining the dynamic evolution of the Uummannaq ice stream onset zone during the last glacial cycle.