<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>D.E. Sugden</dc:contributor>
  <dc:creator>S.S.R. Jamieson</dc:creator>
  <dc:date>2007</dc:date>
  <dc:description>The relative roles of fluvial versus glacial processes in shaping the landscape of Antarctica have been debated since the 
expeditions of Robert Scott and Ernest Shackleton in the 
early years of the 20th century. Here we build a synthesis of 
Antarctic landscape evolution based on the geomorphology of 
passive continental margins and former northern mid-latitude 
Pleistocene ice sheets. What makes Antarctica so interesting 
is that the terrestrial landscape retains elements of a record of 
change that extends back to the Oligocene. Thus there is the 
potential to link conditions on land with those in the oceans 
and atmosphere as the world switched from a greenhouse 
to a glacial world and the Antarctic ice sheet evolved to its 
present state. In common with other continental fragments of 
Gondwana there is a fluvial signature to the landscape in the 
form of the coastal erosion surfaces and escarpments, incised 
river valleys, and a continent-wide network of river basins. 
A selective superimposed glacial signature reflects the presence or absence of ice at the pressure melting point. Earliest 
continental-scale ice sheets formed around 34 Ma, growing 
from local ice caps centered on mountain massifs, and featured phases of ice-sheet expansion and contraction. These 
ice masses were most likely cold-based over uplands and 
warm-based across lowlands and near their margins. For 20 
million years ice sheets fluctuated on Croll-Milankovitch frequencies. At ~14 Ma the ice sheet expanded to its maximum 
and deepened a preexisting radial array of troughs selectively 
through the coastal mountains and eroded the continental
shelf before retreating to its present dimensions at ~13.5 Ma. 
Subsequent changes in ice extent have been forced mainly by 
sea-level change. Weathering rates of exposed bedrock have 
been remarkably slow at high elevations around the margin of 
East Antarctica under the hyperarid polar climate of the last 
~13.5 Ma, offering potential for a long quantitative record 
of ice-sheet evolution with techniques such as cosmogenic 
isotope analysis</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3133/ofr20071047KP05</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>The National Academies Press</dc:publisher>
  <dc:title>Landscape evolution of Antarctica</dc:title>
  <dc:type>reports</dc:type>
</oai_dc:dc>