Luminescence dating at Diepkloof Rock Shelter – new dates from single-grain quartz

Abstract

Diepkloof Rock Shelter, in South Africa's Western Cape, has been the subject of two different luminescence dating projects in recent years (Jacobs et al., 2008; Tribolo et al., 2013) with somewhat divergent results. This paper presents dating analysis of three additional samples from Diepkloof, as well as one sample each from Kathu Pan 6 and Hollow Rock Shelter, also in South Africa. These samples were collected in 1995, prior to the other two projects. Analysis of single-grain quartz shows that the samples are near saturation. Conventional rejection criteria, when applied to dose recovery data, result in an underestimation of dose for high administered doses. Applying the fast ratio (Durcan and Duller, 2011; Duller, 2012) as a rejection criterion removes this underestimation and preferentially rejects grains from the samples with low equivalent dose values. This makes the ages older than they would have been without this criterion. Age results are older than those presented by Jacobs et al. (2008), and slightly older or equivalent to those provided by Tribolo et al. (2013).