Is there evidence for global‐scale forcing of Southern Hemisphere Quaternary desert dune accumulation? A quantitative method for testing hypotheses of dune system development. Issue 14 (7th August 2017)

• Record Type: Journal Article
• Authors: Thomas, David S.G.; Bailey, Richard M.
• Is Part Of: Earth surface processes and landforms. Volume 42:Issue 14(2017)
• Page Start: 2280
• Page End: 2294
• Publication Date: 2017-08-07
• Subjects: luminescence dating -- dune accumulation -- Quaternary -- Southern Hemisphere -- climate forcing; Geomorphology -- Periodicals; 551.4
• DOI: 10.1002/esp.4183
• Languages: English
• ISSNs: 0197-9337

Abstract

Abstract: Luminescence dating of desert dune sediments has generated many hundreds of ages, many used in reconstructions of Quaternary environmental changes, others in attempts to elucidate dune processes. Environmental and climatic interpretations of these records have proved problematic and it remains challenging to test hypotheses of the systematic response of dunefields to changes in external forcing in the past and to make predictions of the future. We use a method that quantifies dune sediment accumulation to interpret dune luminescence age datasets, rather than simply using the ages themselves as proxies of change. The Accumulation Intensity method allows periods of dune sediment accumulation, here over the timescale 10 2 –10 5 years, to be identified from compilations of dated sand sea stratigraphic sequences. We apply this approach to two of the largest dune age datasets, from southern Africa and Australia, testing whether or not dunefield accumulation has co‐varied in the Late Quaternary and whether systematic relationships to external drivers at global, hemispheric, regional and local scales can be identified. Copyright © 2017 John Wiley & Sons, Ltd. Abstract : A new numerical method is presented for analysing the hundreds of luminescence ages that are emerging from studies of desert dunefields. The Accumulation Intensity (AI) model uses full‐age and sediment thickness data to model changes in accumulation through time. This allows dune data to be directly compared alongside other proxies of Quaternary climate and environmental change, greatly improving contributions to testing theories of past earth dynamics. The figure shows southern African AI data alongside other proxy records of past climate.