Neanderthal settlement in central Iberia: Geo-archaeological research in the Abrigo del Molino site, MIS 3 (Segovia, Iberian Peninsula)

The Abrigo del Molino archaeological site is located in the valley of the Eresma river, near Segovia in central Spain. It consists of a shallow cave of fluvio-karstic origin, which has been completely filled with detrital deposits. Geo-archaeological interpretation of the genesis of these deposits differentiates three groups: a lower group with sandy loams and fine sands interbedded with pebble and gravel layers, deposited respectively by palaeofloods and slope contributions; a middle group with massive silt and grain-supported boulders, formed by alternating contributions from the overlying slope, karst mudflows and rockfalls from the shelter roof; and an upper group of silt cemented by carbonates, final backfill alteration and degradation of the host rock. The techno-typological characteristics of the lithic assemblage confirm the existence of Mousterian levels at the site, and optically stimulated luminescence (OSL) dating of these levels obtains an age range of 31-60 ka for the detrital deposits, presenting the occupation by Neanderthal groups for the first time in karstic environments in the northern Iberian plateau, the southern part of the Duero basin.