New radiometric dates on the lowest stratigraphical section (TD1 to TD6) of Gran Dolina site (Atapuerca, Spain)

Ages based on independent methods, such as combined ESR-U series, luminescence, and magnetostratigraphic analyses have been obtained for the upper stratigraphical section of Gran Dolina site (TD6 to TD11 levels). However, the chronostratigraphical framework of this European Paleolithic key site remains incomplete because of its great antiquity and the lack of reliable methods. This paper provides new radiometric dates by electron spin resonance applied to optically bleached quartz grains for the whole stratigraphic sequence. The results agree with the previous chronostratigraphical framework for the upper part of the stratigraphical sequence. The ages for the Homo antecessor remains from TD6 layer range between 800 and 900 ka. The lowest layers attributed to endogenous sediments (TD1) could be contemporaneous with the Sima del Elefante TE9 human bearing layer dated to 1.2 Ma. The results suggest a human occupation of possibly more than 1 Ma at the Gran Dolina site. This study confirms moreover the potential of ESR dating method applied on quartz in karstic environment.