ACCUMULATING RECORDS: INTEGRATING AEOLIAN CHRONOLOGY AND STRUCTURAL DATA TO ENHANCE INTERPRETATION OF QUATERNARY DUNE SYSTEM DEVELOPMENT

For over forty years TL, then OSL, dating has been providing chronometric records of Late Quaternary aeolian dune accumulation from around the globe. Once seen as filling a significant ‘data gap’ in environments where other proxy records are sparse, the growing body (several thousand ages worldwide) of dune ages is in fact more difficult to interpret palaeoenvironmentally than is often recognised, providing somewhat ambiguous records of dune accumulation. In the main difficulties arise in three areas: 1) limitations in understanding the climate/environment controls on dune behaviour; 2) lack of a framework that establishes controls on record accumulation and preservation; and 3) establishing the limitations and impacts of sampling on age data interpretation.

Focussing particularly on 2) and 3), we provide insights and analysis for how we believe dated dune records should/should not be interpreted, what we should/should not expect dated records to yield in terms of dune accumulation histories, and how sampling dune systems in future might occur to maximise the palaeoenvironmental benefits of dune chronological records . We base these proposals on a series of recent investigations including a new quantified dune process model; modelled age regimes from simulated dune accumulations; and new empirical OSL data from Late Quaternary dunes in the UAE where internal structures are well exposed, allowing multiple dating experiments from structure-guided dune sampling.