Optical Dating as a Tool for Studying Dune Reactivation, Accretion Rates and Desertification Over Decadal, Centennial and Millennial Time-Scales

摘要

Optical dating is capable of providing high resolution temporal constraints on dune dynamism and reactivation, and evidence of desertification on decadal to millennial timescales. This potential is demonstrated by application of the method to a large dune from the Northeastern Rub Al Khali within the Ras Al Khaimah emirate. The dune accumulated over the past 1000 years, with 20m of sediment accumulating in a time period of about 270 years. In the absence of widespread evidence of significant changes in aridity, sediment supply or windiness due to natural causes it is inferred that the Idhn dune may have accumulated rapidly over this interval due to intensified human activities related to increased population pressures and associated overgrazing and fuel wood exploitation for copper smelting.