Quaternary Science Reviews 22 (2003) 925–941 Alternative chronologies for Late Quaternary (Last Interglacial–Holocene) deep sea sediments via optical dating of silt-sized quartz S. Stokes a, *, S. Ingram a,d , M.J. Aitken b , F. Sirocko c , R. Anderson d , D. Leuschner e a Oxford Luminescence Research Group, School of Geography and the Environment, University of Oxford, Mansfield Road, Oxford OX1 3TB, UK b Oxford Luminescence Research Group, Research Laboratory for Archaeology and the History of Art, University of Oxford, 6 Keble Road, Oxford OX1 3QJ, UK c Institut f . ur Geowissenschaften, Johannes Gutenberg Universit . at Mainz, Becherweg 21, Mainz 55099, Germany d Lamont Doherty Earth Observatory, Columbia University, Pallisades, NY, USA e Institute for Geophysics and Geology, University of Leipzig, Talstrasse 35, 04103 Leipzig, Germany Received 11 January 2002; accepted 24 October 2002 Abstract We summarize the results of a test on the potential of optical dating for the age assessment of Late Quaternary deep-sea sediments. Our approach combines a single aliquot regeneration (SAR) protocol for equivalent dose (D e ) estimation on fine silt-sized quartz with a time-dependent evaluation of supported and unsupported long-lived radioisotopes within the deposited sediment matrix. For this purpose nine samples from two independently dated deep-sea cores from the Indian Ocean were obtained. The SAR analysis resulted in mean D e estimates with precisions ranging from 0.9% to 3.7%. Combination of these data with measured radioisotope concentrations resulted in stratigraphically sensible ages ranging from ca 7 to 120 ka. These ages exhibit good agreement with existing chronologies for the cores based on radiocarbon age determinations and correlation of key volcanic, palaeoecological and isotopic events. Optical dating may provide an important additional dating method for Late Quaternary deep- sea sediments. r 2003 Elsevier Science Ltd. All rights reserved. 1. Introduction Over late Quaternary timescales, optical dating of the lithogenic fraction of deep-sea sediments provides a possible solution to the need in palaeoceanographic research for high resolution, absolute, proxy-indepen- dent chronologies. Optical dating has rapidly developed over the past decade for terrestrial sedimentary applica- tions (Wintle, 1993, 1997; Prescott and Robertson, 1997; Aitken, 1998; Stokes, 1999). The technique, as devel- oped from thermoluminescence (TL) methods, has been applied in a variety of terrestrial sedimentary environ- ments. Generally, it has been demonstrated that it is possible to generate accurate chronological information for sediments by application of optical dating to purified quartz fractions (e.g. Colls et al., 2001; Rich and Stokes, 2001), while applications exploiting feldspar-dominated fractions have generally resulted in age under-estimation (Balescu and Lamothe, 1994; Lamothe et al., 1994; Duller, 1997). The suitability of a sedimentary environ- ment for dating is based primarily on the likelihood of resetting of the luminescence signal by exposure to daylight. Thus, effort has focused on the analysis of aeolian sedimentary deposits and good agreement with independent age control has been reported (e.g. Stokes and Gaylord, 1993; Rich and Stokes, 2001). Despite its now common and increasing use for the development of terrestrial chronologies (e.g. Pye et al., 1995; Duller and Augustinus, 1997; Stokes et al., 1997; Lang and Nolte, 1999; Colls et al., 2001), optical dating remains virtually untested in the marine environment. TL dating was applied to marine sediments in the late 1970s (Wintle and Huntley, 1979, 1980). Its success was, however, partially limited by large uncertainties (ap- proximately 12–18%) in the resulting age estimates. *Corresponding author. E-mail address: stephen.stokes@geog.ox.ac.uk (S. Stokes). 0277-3791/03/$ - see front matter r 2003 Elsevier Science Ltd. All rights reserved. PII:S0277-3791(02)00243-3