Electrical Resistivity (ERT) geophysical prospection around the caves of Ojo Guareña Complex (Merindad de Sostocueva, Burgos, Spain)

Abstract

Ojo Guareña is one of the largest cave complex in Spain, consisting of a total of 110 km of 14 interconnected cavities, which has an impressive record of Prehistoric activities from the Midlle Paleolithic until the Iron Age. The diversity and variety of the sites include, among others, living areas in cave vestibules, rock art, human bones, grave goods, archaeological objects inside several passages and more than 600 prehistoric human footprints (Ortega et al., 2013). In 1970 this complex was listed as Spanish Cultural Heritage and in 1996 as Castilla y León Natural Heritage. Exploration Tomography was carried out in Ojo Guareña karstic Complex in order to better identify the morphology of caves entrances and passages containing archaeological remains. This geophysical survey was sought to study Kaite and Palomera Caves, both of which have sheltered human occupation at least since Upper Palaeolithic according to the archaeological prospection data (Ortega and Martín, 1986). Fieldwork consisted in the elaboration of Electrical Resistivity Tomography (ERT) profiles of different lengths and arrays. The data provided by 4 ERT profiles have detected and characterized the cave entrance sedimentary thickness and the so far unknown endokarstic morphologies filled with terrigenous sediments. This work helps us to better understanding the entrances of this large karstic system in relation with the use of caves, and to estimate the presence of new infilling archaeo-sedimentary records.