Using 3D models to analyze stratigraphic and sedimentological contexts in archaeo-palaeoanthropological Pleistocene sites (Gran Dolina site, Sierra de Atapuerca)

Abstract

Gran Dolina is a key site to understand Early Pleistocene human evolution in Europe. It has three important Early and Middle Pleistocene archaeo-paleontological layers, where high densities of remains have been found, including hominid bones, fauna and lithic tools. Gran Dolina is a cavity belonging to the second level of the Sierra de Atapuerca multi-level karst system, which shows an Early and Middle Pleistocene sedimentary infilling 25 m thick, divided in eleven lithostratigraphic units. The use of 3D models in stratigraphy and sedimentology is a new issue that allows new analyses and studies, increasing the knowledge of archaeological sites. In Gran Dolina site, the application of 3D laser scanning and photogrammetry techniques have allowed us to carry out 3D models, including RGB textures. The models were georeferenced in the excavation local coordinate system. From these 3D models, we identified and mapped the continuity and geometry of the sedimentary levels, reconstructing the stratigraphic architecture of the site. The 3D geometry of the levels was used to restore the original 3D morphologies of the excavated levels (e.g. TD4 and TD10), revealing the real post-depositional dip of the layers. The last helped us to infer input directions, their variations in each level, and to recognize older sedimentary entrances. With all these data we have elaborated palaeo-geographical reconstructions during the accumulation of the archaeological assemblages.