Electrical resistivity tomography (ERT) for identifying torcas area passages connecting Gran Dolina, Galería Complex and Sima del Elefante sites (Sierra de Atapuerca, Burgos, Spain)

Abstract

Electrical Resistivity Tomography (ERT) carried out in the Sierra de Atapuerca sites (Ortega et al., 2010; Bermejo et al., 2013) has revealed its ability to characterizing the sub-surface geometry, which allows future archaeological planning strategies. This work is specially focused on the Torcas area in which the Gran Dolina, Galería Complex and Sima del Elefante sites, discovered by the railway trench, are located. These sites preserve archaeopalaeoanthropological sedimentary infills dating back to the Early and Middle Pleistocene. The surveying was based on the elaboration of several ERT sections on the Trinchera area and in these sites’ slope. This geophysical survey is aimed to identifying the extension and continuity of passages in the Trinchera multilevel cave system. The result of this exploration, together with previous geophysical, topographic, archaeological, geological and geomorphological data, shows a larger complexity of the karstic system than previously thought. The data confirms the presence of ancient cave entrances filled with sediments which relate to the upper cave level, and the existence of endokarstic morphologies belonging to the intermediate and lower karst level.