Allostratigraphy and Quaternary dune sediments: Not all bounding surfaces are the same

A lack of knowledge of the underlying stratigraphy is often cited as a limitation of dunefield optically stimulated luminescence (OSL) sampling campaigns. Here we examine the role of allostratigraphy in characterising aeolian structural sequences, and the implications of the relationship between visible internal structure and dune accumulation chronologies. We argue that whilst allostratigraphy offers the most appropriate approach to the description of dune internal structure, it has fundamental limitations that reduce the utility of its direct application to constructing chronologies of dune accumulation. Allostratigraphical units are not synonymous with chronologically-distinct accumulation units, and not all significant bounding surfaces are unconformities. Therefore, the utility of an allostratigraphical approach in guiding sampling for OSL dating is limited.