Constraining the Age and Formation of Stone Runs in the Falkland Islands Using Optically Stimulated Luminescence ⁎ James D
Available online at www.sciencedirect.com Geomorphology 94 (2008) 117–130 www.elsevier.com/locate/geomorph Constraining the age and formation of stone runs in the Falkland Islands using Optically Stimulated Luminescence ⁎ James D. Hansom a, , David J.A. Evans b, David C.W. Sanderson c, Robert G. Bingham d, Michael J. Bentley b a Department of Geographical and Earth Science, University of Glasgow, G12 8QQ, United Kingdom b Department of Geography, University of Durham, Durham, DH1 3LE, United Kingdom c Scottish Universities Environmental Research Centre, East Kilbride, G75 0QF, United Kingdom d British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom Received 26 June 2006; received in revised form 25 April 2007; accepted 9 May 2007 Available online 31 May 2007 Abstract The stone runs of the Falkland Islands are thought to be periglacial blockfields but their age and detailed origin remain enigmatic. We examine the fine sediments that underlie two stone runs in order to establish whether Optically Stimulated Luminescence (OSL) dating is an appropriate technique to constrain the date of emplacement of the fine sediments and, hence, the stone runs. Six samples were collected from two accessible sections during the Scotia Centenary Antarctic expedition in 2003. All samples were used to explore the main luminescence characteristics of the sediment, followed by quartz SAR dating procedures on four of the samples. Age estimates range from in excess of 54 ka to 16 ka, suggesting that the overlying stone runs remained active until 16 ka or later. Saturation of luminescence from quartz limits age estimates for the oldest samples in the sequences, however these are not critical to define the upper limit to the emplacement age for the overlying stone runs.
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