Optically stimulated luminescence dating of a Danish Eemian coastal marine deposit: a test of accuracy

It is difficult to test convincingly luminescence dating techniques beyond the range of C-14, and yet this is essential if claims that optically stimulated luminescence dating using quartz can reach back to beyond 10(5) years are to be given credence. One possible approach is to use coastal marine sand identified as Eemian by an examination of the palacoecology. The Eemian period in northern Europe is considered to last from 132 to 116 ka; marine samples are likely to be linked most closely to at least part of this period, and modern coastal sands are known to be well bleached. Thus from a luminescence dating perspective, Eemian marine sand can be considered to be of known age, and it is very likely to be well bleached. We have examined such a 'known age' deposit on the east coast of Jutland, consisting of about 10 m of fine sand, grading up from silty clays and clays in the lower part of the section. This material is confidently expected to have been deposited during the very late Saalian and early mid-Eemian (similar to 133-125 ka). We report on the ages of 25 samples associated with this profile; the observed overall precision is compared with the calculated precision on individual ages, and the mean value of all the ages is compared with the expected mean of similar to 130 ka. (C) 2003 Elsevier Science Ltd. All rights reserved.