%0 Journal Article
%T Residual Doses in Recent Alluvial Sediments From the Ardenne (S Belgium)
%A Dimitri Vandenberghe
%A Cilia Derese
%A Geoffrey Houbrechts
%J Geochronometria
%@ 1897-1695
%D 2007
%I 
%R 10.2478/v10003-007-0024-z
%X We report on our first investigations into the potential of optical dating for determining the rate of river flood sedimentation in the Ardenne region (S Belgium). Two samples collected from a recent alluvial deposit were used to investigate the extent of resetting in different particle size fractions of quartz (4-11 ¦Ìm, 63-90 ¦Ìm, 90-125 ¦Ìm, 125-180 ¦Ìm, 180-212 ¦Ìm and 212-250 ¦Ìm) as well as in polymineral fine (4-11 ¦Ìm) grains. Both samples show satisfactory OSL and IRSL characteristics. The IRSL signals from the polymineral fine grains yield an equivalent dose (De) of 3-4 Gy, while a De of 0.3-0.6 Gy was measured using large aliquots of quartz. Small aliquot analyses of 63-90 ¦Ìm and 212-250 ¦Ìm quartz grains confirm that the coarser fraction contains more grains with lower De's. Furthermore, for a modern sample (< 3 years old), ~60% of the aliquots yields a De consistent with zero, indicating that these contain only well-bleached grains. These findings suggest that it might be possible to extract the true burial dose from dose distributions measured using small aliquots of coarse-grained (e.g. 212-250 ¦Ìm) quartz.
%K optical dating
%K resetting
%K alluvial deposits
%K Ardenne
%U http://versita.metapress.com/content/t67288813541573m/?p=247a280a66f548f485a8304f15c599e5&pi=0