Geomorphology of the Sierra de Atapuerca and the Middle Arlanzón Valley (Burgos, Spain)

Abstract

The Sierra de Atapuerca is Mesozoic inlier composed of an anticlinal ridge belonging to the NW extreme of the Iberian Chain (North-Central Spain, Burgos). In this work, we present a geomorphological map of this area, developed using fieldwork, a 5 m resolution digital elevation model, aerial photographs and geological maps. The map covers 207 km2, synthesizing the geodynamic evolution of this area at 1:25,000 scale, where the geological and geomorphological characteristics of the Sierra de Atapuerca and the Middle Arlanzón Valley have facilitated the formation and preservation of archaeo-palaeoanthropological sites for over one million years. The morphogenesis of this region is determined by polygenetic landform development during the Neogene, with four planation surfaces preserved as plateaus in the landscape. During the Quaternary the incision of exoreic fluvial valleys dominated, forming a downcutting staircase model, where a sequence of 14 strath terraces dating from the Early Pleistocene developed. Other landforms in the area include landslides, cones, semi-endoreic areas, colluvial deposits and karstic landforms.