Search

The Cueva Mayor karst system (Atapuerca, N Spain) contains a set of archaeo-palaeontological sites whose chronology ranges from the Middle Pleistocene to the Iron age. We present here new dating results for two localities, Galería de las Estatuas and Sala de los Cíclopes, which are examined through a combination of numerical dating methods applied to both the fossil assemblage and host sediment. Galería de las Estatuas documents a stratigraphic sequence in which various Neanderthal occupation levels have been identified and has been previously dated to between 112 ka and 70 ka [1,2,3]. We processed two fossil teeth from the current excavation level of one pit (level 4, GE-I) for combined USeries/ ESR and Aspartic Acid Racemization (AAR) methods. The dating results position this archaeological level at the beginning of the Upper Pleistocene. Sala de los Cíclopes contains a palaeontological assemblage formed exclusively of cave-bear bones, hibernation beds and footprints, belonging to the Ursus deningeri species. The estimated age of this deposit, known as Cata Litario, is > 200 ka, pre-dating the closing of the Sima del Elefante/Galería Baja palaeoentrance [4]. One tooth extracted from the Cata Litario pit is dated in the present study, both by Useries/ ESR and AAR methods, while 4 sediment samples collected through the stratigraphic sequence are dated by extended-range luminescence techniques (single-grain TT-OSL and pIRIR). The dating results constrain this bear occupation to the mid-Middle Pleistocene. Beyond the chronological implications of this work, such a combination of independent dating methods may also provide some key insights into the contemporaneity of the sedimentary matrix and the fossil remains. The systematic application of both ESR and AAR to the same fossil specimens enables the identification of any potential methodological biases. [ABSTRACT FROM AUTHOR]

The Sierra de Atapuerca, northern Spain, is known from many prehistoric and palaeontological sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galería and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galería archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galería sites. The authors proposed for Galería an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (>530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galería site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350-450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galería and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data., (Copyright © 2013 Elsevier Ltd. All rights reserved.)