Structural study of two quartzite varieties from the Utrillas facies formation (Olmos de Atapuerca, Burgos, Spain): From a petrographic characterisation to a functional analysis design

Abstract This overall research initiative was undertaken to evaluate the role of lithic raw material variability in use-wear formation processes, focusing specifically on two lithological varieties of quartzite present in the Lower and Middle Pleistocene lithic assemblages of the Gran Dolina, Galeria and Sima del Elefante sites (Sierra de Atapuerca, Burgos). Two Arenas de Utrillas facies varieties (from a sand quarry located in Olmos de Atapuerca) were studied using petrographic and SEM analyses. They were both identified as metaquartzites, revealing differences in their granular structure and metamorphic grade. Sequential experiments employing the same quartzite varieties were then conducted involving different activities and several worked materials, which made it possible to determine use-wear formation on these two quartzite varieties. The results helped to clarify the role of intra-raw material variability in the process of use-wear formation on quartzite and contributed to ongoing studies of the lithic materials from these archaeological sites.