Isles of Scilly: Optically Stimulated Luminescence Dating of Coastal and Intertidal Sediments
Author(s): H M Roberts, Peter Marshall
This report presents the findings of a study using optically stimulated luminescence (OSL) dating to determine the ages of coastal and intertidal sediments from the Isles of Scilly, undertaken as part of the larger Lyonesse Project commissioned by English Heritage’s Historic Environment Enabling Programme (HES project number 2009029), and lead by Charles Johns, Historic Environment Projects, Cornwall Council. The Lyonesse project aimed to study the evolution of the coastal and marine environment of the Isles of Scilly during the Holocene in order to gain a greater understanding of changes in sea-level, the development of the coastal landscape, and the response of human populations to changes in the environment. Intertidal sands from sites around the islands of Tresco and St. Mary’s, and fine-sands from a wetland area east of Hugh Town, St. Mary’s, were dated using the OSL signal from sand-sized quartz, employing a Single Aliquot Regenerative dose (SAR) measurement protocol. Two modern analogue intertidal sediment samples were also dated, giving ages consistent with the present day, indicating that incomplete bleaching is not a problem in this setting. Where more than one OSL age was generated at any section, the ages were in chronostratigraphic order. At some sites, radiocarbon dates were also generated, and in these cases the OSL ages were in agreement with those radiocarbon dates, thus validating both methods in the environments studied. The chronologies generated using both OSL and radiocarbon methods are therefore found to be reliable, and can be used to inform the evolution of the coastal and marine environment of the Isles of Scilly.
- Report Number:
- 2/2013
- Series:
- Research Report
- Pages:
- 35
- Keywords:
- Luminescence Dating Radiocarbon Dating
