2007: Residual OSL signals from modern Greenlandic river sediments. Geochronometria 26

Abstract: Ripple-laminated sandy deposits at shallow water depths in four rivers on Jameson Land, East Greenland were sampled for optically stimulated luminescence (OSL) dating. Silt-sized grains have significantly higher equivalent doses (~1.1 Gy) than sand grains (~0.1 Gy). This suggests that coar...

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Bibliographic Details
Main Author: Helena Alexanderson
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
OSL
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.570.5568
http://www.geochronometria.pl/pdf/geo_26/Geo26_01.pdf
Description
Summary:Abstract: Ripple-laminated sandy deposits at shallow water depths in four rivers on Jameson Land, East Greenland were sampled for optically stimulated luminescence (OSL) dating. Silt-sized grains have significantly higher equivalent doses (~1.1 Gy) than sand grains (~0.1 Gy). This suggests that coarse grain-size fractions are better bleached and more suitable than fine grains for OSL dating of glaciofluvial/fluvial sediments. A sample from a sidebar deposited during the spring flood yielded 1.0 Gy (~500 years) while a subaerial deposit was completely zeroed. The spring flood deposit is consid-ered to be most similar to deglacial conditions and incomplete bleaching of this amount (1 Gy) is generally not a significant source of error for sediments of Pleistocene age. Most samples have rather poor luminescence characteristics and are affected by thermal transfer if preheat temperatures at or above 260°C are used.