Some further observations regarding "cryoplanation terraces" on Alexander Island

Landforms with the appearance of cryoplanation terraces were studied on Alexander Island in an attempt to better understand their formation and growth. Developed on sub-horizontal sedimentary rocks, with 3608 exposure around a nunatak, the terraces show a distinct equatorward orientational preferenc...

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Bibliographic Details
Published in:Antarctic Science
Main Authors: Hall, Kevin John, Andre, Marie-Francoise
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press 2009
Subjects:
Online Access:http://hdl.handle.net/2263/13884
https://doi.org/10.1017/S0954102009990617
Description
Summary:Landforms with the appearance of cryoplanation terraces were studied on Alexander Island in an attempt to better understand their formation and growth. Developed on sub-horizontal sedimentary rocks, with 3608 exposure around a nunatak, the terraces show a distinct equatorward orientational preference and an increase in terrace size with elevation. Available data fail to indicate any evidence of freeze-thaw weathering and information relating to present-day debris transport is singularly absent. Thermal data from the rock exposures showed variability that could cause thermal fatigue but no rates of change of temperature commensurate with thermal shock were recorded. Terrace development appears to be connected with lithological differences in the local sandstones, with growth along sedimentary junctions. Although presently in a permafrost environment, the available information on these landforms does not appear to be compatible with that generally accepted for cryoplanation terraces.