Luminescence chronology of Pleistocene loess deposits from Romania: testing methods of age correction for anomalous fading in alkali feldspars

Abstract

The IRSL dating method is applied to silt-sized alkali feldspar grains (40–60 μm) from Upper and Middle Pleistocene loess deposits of southeastern Romania (sites of Tuzla and Giurgiu Malu-Rosu), using both the multiple aliquot γ dose technique and the SAR method. All samples show evidence of anomalous fading; the measured IRSL ages are in correct stratigraphic order but systematically underestimate the expected geological age (up to 40%). Three protocols of age correction for the observed fading have been tested: the correction of Huntley and Lamothe (Can. J. Earth Sci. 38 (2001) 1093), the correction of Mejdahl (Quat. Sci. Rev. 7 (1988) 357) and the correction model suggested by Wintle (Quat. Sci. Rev. 9 (1990) 385). The three protocols yield corrected IRSL ages that are in better agreement with the expected ages. This study demonstrates the potential of the IRSL dating method to provide chronological information on Upper and Middle Pleistocene loess deposits of Romania.