Atapuerca Karst and its Palaeoanthropological Sites

Abstract

The Sierra de Atapuerca caves are located in the southern flank of an anticline formed by Upper Cretaceous limestones and dolomites. These caves are mainly sub-horizontal passages or water table caves recording palaeodrainage from south to north, roughly parallel to the anticline axis. In the south, groundwater recharge is mainly associated with fractures at the contact between Mesozoic carbonates and the overlying Miocene marls, while the discharge area is located to the north, in the headwaters of the Pico River. The passages are arranged in three main levels interconnected by shafts and chambers. These cave levels are perched around +90, +70 and +60 m above the Arlanzón River, coinciding with the relative heights of fluvial terraces. Episodic fluvial downcutting led to the formation of successively lower karst levels and the entrenchment of the upper conduits under vadose conditions. Accessible dry caves were used by fauna and hominids, preserving an exceptional archaeo-palaeontological record spanning from ~1.2 Myr until the end of the Middle Pleistocene. The sites of Elefante, Gran Dolina, Galería and Sima de los Huesos have provided exceptional findings for understanding the first steps of human evolution in Europe. These sites relate to the occupation of the ancient cave entrances and areas inside the cave.