(Table 3) Age-related trends of desert pavement properties in the Transantarctic Mountains, supplement to: Bockheim, James G (2010): Evolution of desert pavements and the vesicular layer in soils of the Transantarctic Mountains. Geomorphology, 118(3-4), 433-443

• Main Author: Bockheim, James G
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2010
• Subjects: Event label; Latitude of event; Longitude of event; Area/locality; Description; Epoch; Crystal size; Boulder; Cobble; Pebble; Desert pavement, density; Ventifacts; Ratio; Varnish; Macropitting; Index; Layer thickness; Parameter; Depth, relative; Sampling by hand; International Polar Year 2007-2008 IPY; Antarctic; Transantarctic Mountains; Bockheim; Antarc*; Antarctica; International Polar Year; IPY
• Online Access: https://dx.doi.org/10.1594/pangaea.807589; https://doi.pangaea.de/10.1594/PANGAEA.807589

Compared to mid-latitude deserts, the properties, formation and evolution of desert pavements and the underlying vesicular layer in Antarctica are poorly understood. This study examines the desert pavements and the vesicular layer from seven soil chronosequences in the Transantarctic Mountains that have developed on two contrasting parent materials: sandstone-dolerite and granite-gneiss. The pavement density commonly ranges from 63 to 92% with a median value of 80% and does not vary significantly with time of exposure or parent material composition. The dominant size range of clasts decreases with time of exposure, ranging from 16-64 mm on Holocene and late Quaternary surfaces to 8-16 mm on surfaces of middle Quaternary and older age. The proportion of clasts with ventifaction increases progressively through time from 20% on drifts of Holocene and late Quaternary age to 35% on Miocene-aged drifts. Desert varnish forms rapidly, especially on dolerite clasts, with nearly 100% cover on surfaces of early Quaternary and older age. Macropitting occurs only on clasts that have been exposed since the Miocene. A pavement development index, based on predominant clast-size class, pavement density, and the proportion of clasts with ventifaction, varnish, and pits, readily differentiated pavements according to relative age. From these findings we judge that desert pavements initially form from a surficial concentration of boulders during till deposition followed by a short period of deflation and a longer period of progressive chemical and physical weathering of surface clasts. The vesicular layer that underlies the desert pavement averages 4 cm in thickness and is enriched in silt, which is contributed primarily by weathering rather than eolian deposition. A comparison is made between desert pavement properties in mid-latitude deserts and Antarctic deserts. : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150