Focus Area Groups

Focus Areas Detail

Aeolian history of deserts and arid regions

(Leader: Nick Lancaster)

Deserts, defined by lack of water and low density of vegetation cover, some 26.2 million square kilometers, or about 20% of the earth’s land surface. Quaternary glacial-interglacial cycles profoundly affected the evolution of the physical and biotic environments of desert regions – with periods of intense and widespread aridity and enhancement of aeolian processes interspersed with episodes of widespread increased rainfall, which resulted in the formation of extensive paleolakes, vegetation-stabilized dune systems, paleosols, and alluvial fans.

Dune systems and aeolian deposits (including desert margin loess) provide a valuable source of information on past climate conditions in desert and desert margin areas, including unique data on past wind regimes. Until recently, periods of aeolian deposition could only be dated indirectly by reference to stratigraphic relations to deposits or features dated using radiocarbon (e.g. lacustrine deposits; buried soils). Such an approach has provided a large amount of data on the chronology of periods of aeolian deposition, but often with a very broad temporal resolution. In the past two decades, the development of luminescence dating techniques has provided the means to directly date periods of aeolian deposition, by determining the time elapsed since burial. This has resulted in an explosion of information on the chronologies of aeolian deposition in many desert regions as well as in the semi-arid areas that adjoin them.

The goal of this focus area is to develop an improved understanding of the history of aeolian processes in arid regions so that more precise correlations of periods of aeolian deposition may be made to other terrestrial and marine palaeoclimatic proxies and records. Such correlations will result in improved understanding of the conditions in which aeolian deposits form as well as the climate history of low latitude arid regions. The primary means to achieve the goal of the focus area is through the development of a digital atlas of Quaternary dunefields and sand seas. The digital atlas database will incorporate information on dune morphology, activity status, and dune chronology, so enabling regional and global correlation of periods of dune construction or reworking via construction of time-slice maps of dune development and extent.

The focus area will also establish links with other groups working on Quaternary aeolian processes including, but not limited to:

1. DIRTMAP (Dust Indicators of Terrestrial and Marine Paleoenvironments)
   http://www.bridge.bris.ac.uk/projects/DIRTMAP
2. QUEST Working Group on Dust
   http://www.bridge.bris.ac.uk/projects/dust/QWGD_files/Page499.htm
3. Loess letter group (Ian Smalley)
   http://www.leicestercitycouncil.co.uk/loessletter/

Steering Committee members

Nick Lancaster (chair)
Desert Research Institute
Reno, NV 89512, USA
Nick.Lancaster@dri.edu

Professor David S.G. Thomas
School of Geography
University of Oxford
South Parks Road
Oxford
OX1 3QY
United Kingdom

Ashok Singhvi
Planetary and Geosciences Division
Physical Research Laboratory
Navrangpura, Ahmedabad, INDIA 380 009

Paul Hesse
Department of Physical Geography
Macquarie University
Sydney, Australia

Haim Tsoar
Department of Geography and Environmental Development
Ben-Gurion University of the Negev
Beersheva, Israel

Dan Muhs
US Geological Survey
Denver, Colorado, USA