Geomorphology of Antarctica

  1. J. C. F. Tedrow
  1. Robert L. Nichols

Published Online: 14 MAR 2013

DOI: 10.1029/AR008p0001

Antarctic Soils and Soil Forming Processes

Antarctic Soils and Soil Forming Processes

How to Cite

Nichols, R. L. (1966) Geomorphology of Antarctica, in Antarctic Soils and Soil Forming Processes (ed J. C. F. Tedrow), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR008p0001

Author Information

  1. Department of Geology, Tufts University, Medford, Massachusetts

Publication History

  1. Published Online: 14 MAR 2013
  2. Published Print: 1 JAN 1966

ISBN Information

Print ISBN: 9781118655801

Online ISBN: 9781118668719

SEARCH

Keywords:

  • Geomorphology;
  • Glacial and subglacial topography;
  • Glaciation and deglaciation;
  • Kukri and tertiary peneplain;
  • Lakes and beaches;
  • Marine-boulder paveme and dry valleys;
  • Paleozoic antarctic glaciation and pre-glacial fluvial cycle;
  • Running water and wind work;
  • Tertiary antarctic glaciation and tertiary block-fault mountains;
  • Volcanic landforms and wave-washed surfaces

Summary

The Kukri Peneplain, located in part in south Victoria Land, is Lower Paleozoic or older and has been traced for over a thousand miles. Although a Permocarboniferous tillite containing striated fragments and resting on a glaciated pavement is found in the Horlick Mountains, there is no good evidence for Tertiary antarctic glaciation. The summit of the Antarctic Peninsula, a snow-covered plateau, is a differentially uplifted, dissected peneplain. The major features of the bedrock topography for much of Antarctica are the result of late Cenozoic block-faulting modified by glacial and fluvial erosion. Throughout Antarctica volcanic landforms are widespread and numerous. Glacial marine sediments completely surround the continent, covering not only the continental shelf but also the slope and adjacent ocean bottoms. The antarctic continental shelf, the deepest in the world, is characterized by both transverse depressions, due to glacial erosion, and longitudinal depressions, which may be due, in part, to glacial erosion. Multiple glaciation in the McMurdo Sound area has been demonstrated by several workers. Interglacial deposits have also been identified. Data from the first expedition to winter in the Antarctic, which were subsequently substantiated, prove that formerly the glaciers of Antarctica were more extensive. Elevated beaches, found on all sides of the continent, in general postdate the youngest glaciation. The highest are more than a hundred feet above sea level, their elevation being due to isostatic rebound following déglaciation. Some are pitted, owing to the melting of the ice on which they rest. Dry kettles and small saline lakes, surface and subsurface efflorescences of salts, calcite-veneered fragments, and undrained lakes that have very small areas in comparison to their basins, all prove that the deglaciated valleys and coastal areas around McMurdo Sound have been arid for thousands of years. Felsenmeers, nivation cirques, and solifluction deposits are found in the McMurdo Sound area, and frost-crack polygons are common and widely distributed. A careful study of a badly weathered fine-grained quartz diorite found at Marble Point, McMurdo Sound, showed that the breakup was due essentially to physical rather than chemical changes. Ice-cored moraines thousands of years old and covering scores of square miles are found in the McMurdo Sound area. Where the morainal topography is flat and the ice thus effectively and continuously covered with moraine, the ice-cored moraines will persist as long as present-day conditions continue, for the mean annual temperature is below 0°F. Fans, deltas, kames, valley trains, marginal channels, and nonpaired terraces, all formed by melt water, occur. Ventifacts are unusually well developed and numerous in the McMurdo Sound area. More than 1 foot of rock has commonly been removed from the larger ventifacts, and in a 3-foot-square area 53 ventifacts 1–5 inches long were counted. Since the mean annual air temperature at sea level in the McMurdo Sound area, as determined from bedrock, glacier, and air temperatures and from sea-ice thickness, is approximately -2°F, perennially frozen lakes are present.