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

• Main Author: Helena Alexanderson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: luminescence dating; OSL; glaciofluvial; fluvial; bleaching; Greenland; Jameson Land; East Greenland; greenlandic
• 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

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.