Glacial geomorphology, soil development and permafrost features in central-upper Wright Valley, Antarctica

Abstract

We mapped surficial deposits, soils and permafrost features in the central-western Wright Valley, Antarctica, from Lake Vanda in the east to near the mid-part of the South Fork in the west. Outstanding features of the landscape include two large rock glaciers covering approximately 323 ha with a volume of 0.14 km3, and the sinuous Upper Wright III moraine in the South Fork with typifying yellowish brown (10YR 5/6) subsoil colours. Soil morphology and weathering stage indicate the features are early Quaternary age and younger than Alpine III deposits. Soils are dominated by sodium and chloride ions, and the total salt content increases with age except where profile soil water is recharged either by subsurface flow from streams, melt water production at high elevation or sporadic surface flow. Ice-cemented permafrost at less than 70 cm depth is common, being associated with relatively young alluvial soils of the Onyx River, and with soils on the steep slopes of the south valley wall near the Dais where melt water from high elevation recharges soil water.