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Submarine landforms and shallow acoustic stratigraphy of a 400 km-long fjord-shelf-slope transect, Kangerlussuaq margin, East Greenland

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posted on 06.09.2013, 10:11 by Julian A. Dowdeswell, Jeffrey EvansJeffrey Evans, Colm O Cofaigh
Kangerlussuaq Fjord is a relatively uniform, steep-walled basin, whose floor has an almost smooth surface. Debris is supplied mainly from icebergs from the fast-flowing Kangerlussuaq Glacier. Sedimentation after iceberg release from multi-year sea ice is mainly by rain-out of fine-grained englacial debris. Streamlined glacial lineations and drumlins were produced at the sedimentary bed of an ice sheet that expanded into Kangerlussuaq Trough at the Last Glacial Maximum (LGM). Bedrock channels and crescentic overdeepenings indicate warm-based ice and free water beneath parts of the former ice sheet. Cross-cutting iceberg scour marks, which characterise outer Kangerlussuaq shelf, were produced not only during deglaciation, but also occasionally through the Holocene by deep-keeled icebergs from further north in East Greenland. The outward-convex contours of the shelf edge and slope beyond Kangerlussuaq Trough, and debris flows on the slope, suggest a glacier-influenced high-latitude fan. The distribution of streamlined subglacial landforms demonstrates that the Greenland Ice Sheet extended throughout Kangerlussuaq Fjord and reached at least 200 km across the shelf in Kangerlussuaq Trough at the LGM. Streamlined landform orientation indicates ice flow from the interior of Greenland down the axis of Kangerlussuaq Trough. There is little evidence for discrete sedimentary depocentres in the trough, implying that ice probably retreated rapidly from the outer and mid shelf during deglaciation.

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School

  • Social Sciences

Department

  • Geography and Environment

Citation

DOWDESWELL, J.A., EVANS, J. and O COFAIGH, C., 2010. Submarine landforms and shallow acoustic stratigraphy of a 400 km-long fjord-shelf-slope transect, Kangerlussuaq margin, East Greenland. Quaternary Science Reviews, 29 (25-26), pp. 3359 - 3369.

Publisher

© Elsevier Ltd.

Version

AM (Accepted Manuscript)

Publication date

2010

Notes

This article was published in the journal, Quaternary Science Reviews [© Elsevier Ltd.] and the definitive version is available at: http://dx.doi.org/10.1016/j.quascirev.2010.06.006

ISSN

0277-3791

Language

en

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