HR: 10:50h
AN: C12C-03    [Abstracts]
TI: Meltwater flood landforms created beneath a Miocene ice sheet, Transantarctic Mountains
AU: * Sugden, D
EM: David.Sugden@ed.ac.uk
AF: School of GeoSciences, University of Edinburgh, Grant Institute, The King's Buildings, Edinburgh, EH9 3JW United Kingdom
AU: Denton, G
EM: debbies@maine.maine.edu
AF: Department of Geology,University of Maine, Bryand Global Sciences Center, University of maine, Orono, Mai 04469 United States
AB: We illustrate spectacular meltwater landforms associated with an ice sheet that overrode the Transantarctic Mountains in southern Victoria Land around 14 million years ago. Subglacial channels systems commonly originate near divides and converge downhill toward the northeast. One channel system in the Convoy Range is more than 30 km long and drops about 1000 m in elevation. High-elevation divides in sandstone cols show ice sculpturing, with flow toward the northeast. Bedrock in leeside slopes and platforms is commonly stripped of unconsolidated deposits and bears corrugations, potholes, plunge pools and scabland. We conclude that a major Antarctic Ice Sheet submerged the area as it flowed northeastward toward the outer Antarctic continental shelf. The meltwater landforms and scabland with preserved patches of regolith are best explained by the breaching of cold-based ice on the mountain rim by subglacial meltwater outbursts. Melt from warm-based ice, along with subglacial lakes trapped upstream of the mountain rim, are possible sources of the meltwater necessary to form the channel systems and scablands.
DE: 0726 Ice sheets
DE: 0746 Lakes (9345)
DE: 0768 Thermal regime
DE: 0776 Glaciology (1621, 1827, 1863)
SC: Cryosphere [C]
MN: Fall Meeting 2005