Landscape evolution in Antarctica

Abstract

The extreme aridity of Antarctica means that very little water is available for weathering and geomorphic processes. The landscape everywhere has been shaped by ice, but land exposed after ice retreat has been modified by cold desert weathering processes. Wind is the main agent for removal and redeposition of weathered material, while fluvial action is insignificant as an eroding or transporting agent. There are few suitable deposits that allow reliable or accurate dating of events but the dates that are available show that landform evolution has been taking place very slowly. Soil weathering studies have provided a useful means of extrapolation showing relative ages of surfaces where no dates are available. The major weathering processes in Antarctica involve patterned ground movement, frost action, wind, salt weathering, and soil weathering. These combine to form distinctive landscape features. The complex nature of landform development is illustrated by considering events that have taken place within Wright Valley, one of the largest ice-free areas in Antarctica. Within this valley are land surfaces ranging from those found on Late Pleistocene up-valley tills, to high altitude extremely fretted and weathered land surfaces that have been ice-free possibly since the Early Miocene.