Some further observations regarding “cryoplanation terraces” on Alexander Island

• Published in: Antarctic Science
• Main Authors: Hall, Kevin, André, Marie-Françoise
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2009
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Alexander Island; Antarctic Science; permafrost
• Online Access: http://dx.doi.org/10.1017/s0954102009990617; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102009990617

Abstract 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 360° 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.