OSLdating of theMiddlePalaeolithicHotelCalifornia site,SierradeAtapuerca, north‐centralSpain

Abstract

In this study we present optically stimulated luminescence (OSL) dating results obtained at one of the most important open‐air Middle Palaeolithic sites in the Sierra de Atapuerca foothills – Hotel California. We also assess the possibility of obtaining extended‐range OSL chronologies for a nearby Middle Pleistocene fluvial deposit using several novel methods, namely OSL dating of individual quartz ‘supergrains’, multi‐grain aliquot thermally transferred OSL (TT‐OSL) dating and the first application of a single‐grain TT‐OSL dating procedure. Four single‐grain OSL ages constrain the Middle Palaeolithic occupation of Hotel California to between 71±6 and 48±3 ka. The Hotel California single‐grain equivalent dose (De) distributions are highly overdispersed and contain several dose populations, which are probably attributable to post‐depositional sediment mixing, partial bleaching and intrinsic scatter. The reliability of multi‐grain aliquot OSL dating is compromised by the complex underlying De dispersion affecting these samples, as well as by biasing multi‐grain averaging effects. Extended‐range OSL and TT‐OSL chronologies for the nearby Pico River terrace are consistent with each other and with broad independent age control. These experimental approaches yield a weighted average age of 348±16 ka for terrace TA9 of the Arlanzón River sequence. Our results highlight the benefits of comparing ages obtained using several OSL methodologies to improve the robustness of luminescence chronologies. They also demonstrate the potential that single‐grain OSL techniques offer for establishing improved age constraints on the many other Middle Palaeolithic sites found at Atapuerca and elsewhere across north‐central Spain.

Optical dating of flowstone and silty carbonate-rich sediments from Panxian Dadong Cave, Guizhou, southwestern China

“…Similar results have also been reported for Middle Pleistocene sediments whose OSL ages are consistent with the independent age control when dating in the high dose part of quartz SAR DRCs (e.g. Murray et al, 2008;Pawley et al, 2010;Arnold et al, 2013). However, the reliability of the OSL ages of the three samples (L2161e2163) from the bottom layer (Layer XII) are difficult to assess because of no independent age control.…”

Reassessing the age of Atapuerca-TD6 (Spain): new paleomagnetic results

“…When considered in this manner, the TL chronologies of <820 ka and <960 ka for deposits overlying and underlying the new magnetozone are compatible with the interpretation that chron N1 represents the Kamikatsura-Santa Rosa events rather than Jaramillo Subchron. However, additional luminescence studies using extended-range optical dating techniques (raised temperature post-IR IRSL, thermally-transferred OSL, individual quartz 'supergrains'; e.g., Arnold et al, 2013) would be advisable to improve the precision of the existing TL chronologies, and to better constrain uncertainties related to partial bleaching and anomalous fading.…”

High-resolution OSL dating of a late Quaternary sequence from Xingkai Lake (NE Asia): Chronological challenge of the “MIS 3a Mega-paleolake” hypothesis in China

“…This has been demonstrated in the comparison of the natural-and laboratory-generated DRCs for loess quartz (Chapot et al, 2012;Timar-Gabor et al, 2012), although several studies obtained reliable age results from the high-dose region, according to comparisons with other independent age controls (e.g., Murray et al, 2008;Pawley et al, 2010;Arnold et al, 2013). To check whether the laboratory-generated quartz OSL signals are suitable for determining D e for our samples (especially for the relatively old sediments), the quartz OSL ages of seven samples (NL-4, NL-7, NL-8, NL-17, NL-22, NL-24, and NL-25) were compared with their corresponding polymineral pIRIR 290 ages (Fig.…”