Geochronology for some key sites along the coast of Sardinia (Italy)

Recent stratigraphic surveys and facies analyses have questioned long-held interpretations of the development and furthermore the age of Quaternary sediments along the coast of Sardinia. The matter of debate is whether the investigated sediments were deposited during the Late Würmian and Holocene or during marine isotope stage (MIS) 5 and older stages. Optically stimulated luminescence (standard blue optically stimulated luminescence (OSL), post-infrared (IR) pulsed blue OSL and post-IR infrared stimulated luminescence (IRSL)) dating was applied to shallow marine and aeolian deposits as well as radiocarbon dating to bulk organic material in palaeosols. Radiocarbon dates suggest sedimentation during the Late Würmian and Holocene, whilst the luminescence results for both quartz and potassium feldspar indicate a depositional age for most of the investigated sites prior to and during MIS 5. From a geochronological point of view the luminescence ages are considered reliable because they passed all quality tests; furthermore there is good agreement of two dosimeters with different bleaching and luminescence properties. The radiocarbon ages might suffer from underestimation due to some contamination with young carbon, which however cannot be large enough to yield such young ages.