Eolian deposits of the ice‐free Victoria Valley, Southern Victoria Land, Antarctica

The most widespread eolian deposits of the Victoria Land dry valleys, Antarctica, are pebble ripples which appear to b“ of larger size than those r,eported from other continents. The crests of the ripples are composed of grains with a greater diameter than the grains of the flanks. The mean ripple index of 23 is higher than that of large ripples reported from outside Antarctica, and there does not seem to be a simple relationship between index and grain size. The high winds and high‐density cold air of Antarctica appear capable of moving the largest pebbles which have a diameter of 19 mm. Sand forming transverse and whaleback dunes in the Victoria Valley is derived from the outwash from the Victoria Lower Glacier. The sand in the dunes is interbedded with snow, and moisture from this allows the dunes to be permafrosted except for a thin surface layer of dry mobile sand. The mobile sands of the transverse dunes are seasonally reversing. The sands of the dunes are well sorted and there is no selective deposition of a particular grain size in any area of the dunes. A characteristically granule‐size lag deposit occurs on some interdune areas, and on the wha1ehack dunes, where it controls the size of the ripples. The granules may be in the critical size range for stabilising ripples which move only during infrequent very high velocity winds.