Single-grain and multi-grain OSL dating of river terrace sediments in the Tabernas Basin, SE Spain

River terraces represent important records of landscape response to e.g. base-level change and tectonic movement. Both these driving forces are important in the southern Iberian Peninsula. In this study, Optically Stimulated Luminescence (OSL) dating was used to date two principal river terraces in the Tabernas Basin, SE Spain. A total of 23 samples was collected from the fluvial terraces for dating using quartz OSL. Sixteen of the samples could not be dated because of low saturation levels (e.g. typical 2xD0 < 50 Gy). The remaining seven samples (5 fossil and 2 modern analogues) were investigated using both multi-grain and single-grain analysis. Single grain results show that: (i) measurements from multi-grain aliquots overestimate ages by up to ∼ 4 ka for modern analogues and young samples (<5 ka), presumably because (ii) the presence of many saturated grains has biased the multi-grain results to older ages. Despite the unfavourable luminescence characteristics we are able to present the first numerical ages for two terrace aggradation stages in the Tabernas Basin, one at ∼16 ka and the other within the last 2 ka

A Marine Isotope Stage 4 age for Pleistocene raised beach deposits near Fethard, southern Ireland

Raised beach deposits around the Irish coast have been interpreted as interglacial or last glacial in age. On the south coast of Ireland, the Courtmacsherry Formation raised beach (CFB), near Fethard, County Wexford, was dated using optically stimulated luminescence (OSL). This site was previously dated to Marine Isotope Stage (MIS) 6–5, but more recent dating of the CFB elsewhere along the south coast shows it is considerably younger (MIS 4–3). The OSL analyses in this paper aimed to determine if new dating would support the greater age of the Fethard raised beach or realign it with the CFB. The new OSL ages place the formation of the Fethard raised beach between 57 ± 6 and 45 ± 6 ka, with 53 ± 5 ka the most likely age if a single depositional event is assumed. This is consistent with OSL dates of the CFB elsewhere. An MIS 4–3 age has important implications in understanding the palaeogeography and timing of glaciation in Ireland, and requires a reassessment of regional relative sea level history. As the eustatic response to global ice volume resulted in lowered relative sea level during MIS 4–2, a crustal response to glaciation is implied by the new dates

Testing the applicability of a standardized growth curve (SGC) for quartz OSL dating: Kalahari dunes, South African coastal dunes and Florida dune cordons

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