Optically stimulated luminescence (OSL) dating of coastal aeolian sand accumulation in Sanday, Orkney Islands, Scotland

Abstract

Optically stimulated luminescence (OSL) dating of sand has been used to identify periods of enhanced aeolian activity at two coastal archaeological sites in Orkney that coincide with periods of Holocene climatic deterioration recorded elsewhere in both Scotland and W Europe. Areas of Tofts Ness, Sanday were settled from the Neolithic, abandoned in the late Neolithic/early Bronze Age, reoccupied and permanently abandoned in the Iron Age. Sand layers above the Neolithic soils have been OSL dated to about 4000 BP, correlating well with a period of increased aeolian activity elsewhere in W Europe. OSL dating of aeolian sands above midden deposits and a Bronze Age burial at Lopness on Sanday suggest dune development by 3000 BP, although both sites also contain sand that was deposited during the `Little Ice Age'. Several possible mechanisms may have contributed to an increase in aeolian activity during the Holocene that led to the abandonment of these sites. Although volcanic eruptions in Iceland cannot be discounted as a contributory factor, a more likely driver of change in sand dune systems is the enhanced N Atlantic storminess suggested by ice core records from Greenland. During periods of climatic deterioration the declining productivity of other agricultural land places enhanced demands on agriculturally marginal sand dunes, leading to further destabilization and the potential for enhanced sand transport events.

Decline in firing technology or poorer fuel resources? High-temperature thermoluminescence (HTTL) archaeothermometry of Neolithic ceramics from Pool, Sanday, Orkney

“…This value is highly concordant with an optically stimulated luminescence (OSL) date of 2210±135 BC (Sommerville et al, 2007) for a sand layer associated with the rich prehistoric landscape of Tofts Ness located on the northeast peninsula of Sanday ( Fig. 1; Dockrill et al, 2007).…”

“…1; Dockrill et al, 2007). The Tofts Ness sand blow event is potentially associated with site abandonment, and synchronous with Hekla 4 and with increased salinity records in Greenland ice cores (Sommerville et al, 2007). The presence of wind blown sands linked to climatic deterioration at Tofts Ness, and the relation of the two sites via sand markers and chronology, further supports a model of climatically driven fuel resource availability at Pool in the Mid-Late Neolithic.…”

Optically stimulated luminescence dating of young sediments: A review

“…7a are the OSL ages by Ballarini et al (2003), which were identified as incorrectly sampled based both on the OSL age and subsequent field checking. Note that the data of Wolfe et al (1995) and Sommerville et al (2007) have been excluded from this comparison because the age control is patently in error. The agreement between OSL and independent ages shown in Fig.…”

“…Three periods of increased aeolian sand activity were identified by Sommerville et al (2007) at Sanday on the Orkney Islands, Scotland, using OSL dating. They undertook SAR measurements on sandsized quartz and obtained ages for the coastal dunes ranging between 265 ± 80 years and 5255 ± 220 years.…”

Climate control on late Holocene high-energy sedimentation along coasts of the northeastern Atlantic Ocean

“…Onshore, HSPs are associated with the widespread formation of massive aeolian dune fields and coversands stretching along the coasts of western Europe (Alexanderson and Bernhardson, 2016;Bateman and Godby, 2004;Clarke et al, 2002;Clarke and Rendell, 2006;Clemmensen et al, 1996;Clemmensen and Murray, 2006;Clemmensen et al, 2009;Costas et al, 2013Costas et al, , 2012Costas et al, , 2016Gilbertson et al, 1999;Jelgersma et al, 1995;Nielsen et al, 2016;Sommerville et al, 2007;van Vliet-Lanoë et al, 2016;Wilson and Braley, 1997;Wilson et al, 2004), also recorded as the deposition of thin windblown quartz layers over soils (Jackson et al, 2005) and peat bogs (Björck and Clemmensen, 2004;de Jong et al, 2006de Jong et al, , 2007Kylander et al, 2016;Orme et al, 2015Orme et al, , 2016Sjögren, 2009;Tisdall et al, 2013). Aeolian activity was initiated during the last glacial termination (Costas et al, 2016) that gave rise to the periglacial "European Sand Belt" (Zeeberg, 2008), the most recent phase of dune formation being the LIA.…”