Towards chronologies of gully formation: optical dating of gully fill sediments from Central Europe

Relic gullies are commonplace in the hill landscapes of Central and Western Europe. Understanding their formation is essential to identify how landscapes respond to environmental change and especially high magnitude rainfall events. The relic gully systems were studied intensively but their genesis is still a matter of debate, the major problem being insufficient information on the timing of their formation and infilling.Here we investigate if optical dating of quartz can be used to determine the ages of relic gully systems. We studied known age deposits and used quartz grains of different size fractions. Based on single-aliquot regenerative-dose protocols equivalent doses were estimated, the dose distributions analysed, and minimum age models calculated.The results show that in many cases optical dating can be successfully applied. Larger grains seem to be better bleached, as optical ages of the coarsest grain-size fractions (middle sand) are in agreement with independent age information from 14C-dating and historical sources whereas optical ages of smaller grain-size fractions (fine sand) are overestimates.