Luminescence dating of Holocene aeolian sand movement, Thy, Denmark

Abstract

We report on the application of optically stimulated luminescence dating to an investigation of the frequency of periods of aeolian sand movement and dune formation. On the coast of Thy, Holocene aeolian sediments, interleaved with peaty palaeosols, form some of the most complete successions known in western Denmark. Samples were taken from a coastal exposure, and an inland archaeological site. Dosimetry was based on laboratory gamma spectrometry, and quartz luminescence measurements used the single-aliquot regenerative-dose protocol, and 470±30 nm stimulation. The sand samples cover an age ranging from about 100 years to 4500 years; the youngest dates give us confidence that the material was well bleached at deposition. Good agreement was obtained with the radiocarbon palaeosol ages. We identify three main periods of aeolian sand movement, starting at about 4200, 2700 and 900 years ago; at least during the latter two periods significant aeolian sand movement occurred. All three phases of aeolian activity were separated by long periods of stability and soil formation. A more recent episode of dune formation, restricted to the coast and beginning less than 200 years ago, may have been triggered by modern coastal erosion.