Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-19T11:38:04.340Z Has data issue: false hasContentIssue false

Late Quaternary sediment facies in Prydz Bay, East Antarctica and their relationship to glacial advance onto the continental shelf

Published online by Cambridge University Press:  07 May 2004

Eugene Domack
Affiliation:
Department of Geology, Hamilton College, Clinton, NY 13323, USA
Phil O'Brien
Affiliation:
Australian Geological Survey Organization (AGSO), GPO Box 378, Canberra, ACT 2601, Australia
Peter Harris
Affiliation:
Antarctic Cooperative Research Centre (CRC), GPO Box 252-80, Hobart, TAS 7050, Australia
Fiona Taylor
Affiliation:
Department of Geology, Hamilton College, Clinton, NY 13323, USA Antarctic Cooperative Research Centre (CRC), GPO Box 252-80, Hobart, TAS 7050, Australia
Patrick G. Quilty
Affiliation:
Antarctic Cooperative Research Centre (CRC), GPO Box 252-80, Hobart, TAS 7050, Australia Australian Antarctic Division, Channel Highway, Kingston, TAS 7050, Australia
Laura De Santis
Affiliation:
Osservatorio Geofisico Sperimentale, PO Box 2011, 34016 Opicina (TS), Italy
Benjamin Raker
Affiliation:
Department of Earth and Environmental Sciences, Wesleyan University, Middletown, CT 06459, USA

Abstract

A marine survey in Prydz Bay, provides an unparalleled view of glacigenic and marine sedimentation across Prydz Channel and Amery Depression during the Late Quaternary. Gravity cores and a suite of eight radiocarbon dates indicate that the Late Wisconsin Glacial Maximum (LGM) was associated with grounding of a palaeo-ice shelf along the periphery of Prydz Channel. Deposition in front of the grounding line was dominated by ice-rafting. A granulated facies, containing angular clay and diamicton clasts, was producd by a combination of regelation freezing, near to the grounding line, and remelting of this basal debris in the sub-ice shelf setting. Beneath these LGM marine deposits lie two key beds of diatom ooze that are distinct in size sorting and Pliocene diatoms. These “interstadial” units can be traced across most of the Prydz Channel, and are underlain by additional glacial marine units. Debris related to the Lambert Deep is distinct from detritus from eastern Prydz Bay and deposition of these two sources within the channel oscillated during the LGM. We suggest that coastal drainage systems contributed to a limited glaciation of the shelf during the LGM, rather than direct outflow via the Lambert/Amery system. It is proposed that shelf-wide glaciation is related to the duration of glacial sea level lowstands rather than the absolute magnitude of eustatic fall during such episodes.

Type
Earth Sciences
Copyright
© Antarctic Science Ltd 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)