A large acheulean LCT accumulation in the Iberian Middle Pleistocene (MIS 8-7): the Porto Maior site (Galicia, Spain)

Abstract

Porto Maior (Galicia, Spain) is a Middle Pleistocene acheulean site located in the lower Miño basin (NW of Iberian Peninsula), which documents the existence of an extensive accumulation of large cutting tools (LCTs). The stratigraphic sequence of the site is made by a succession of several fluvial layers belonging to the terrace level + 34 m above the current level of the Miño River. The chronology of the site has been established by the combination of two numerical dating methods, Electron Spin Resonance -ESR- applied to optically bleached quartz and Post infrared (IR) IR stimulated luminescence -pIR-IR- applied to coarse K-rich feldspar grains. They provide consistent age results and constrain the chronology of the main acheulean levels between ca. 300-200 ka. The lithic industry consists primarily of quartzite handaxes of large size when compared to previous finds on the European continent. Taphonomic observations indicate that most of the LCTs are found in an autochthonous position. The chronology of Porto Maior coincides with a period of marked expansion of Acheulean technology in SW Europe, as well as the occurrence of Early Middle Paleolithic technologies at other sites in the region. Traditionally, the Acheulean technocomplex of southwest Europe has been linked with its African counterpart. In particular, the use of LCTs made from large flake and the presence of flake cleavers at Iberian Acheulean sites provide clear evidence for technological affinities with the African Acheulean technocomplex. Another characteristic feature of the African Acheulean is the existence of occupation sites characterised by large numbers of LCTs. However, until very recently the only known deposits with this type of occupation found outside of Africa have been identified in the Near East. The techno-cultural and occupation pattern evidence from Porto Maior provides support for a cultural connection between Africa and SW Europe.