Radiocarbon Chronology at the AEP-1 Rockshelter in Piedra Museo Locality: An Update and Discussion of the Datings

Abstract

This chapter presents the compilation and critical analysis of radiocarbon dates from the AEP-1 site at Piedra Museo locality in order to achieve a better understanding on the stratigraphic sequence and the environmental conditions during the human occupations of this site. The lithological and morphological features of the AEP-1 site sedimentary filling consist of two lithostratigraphic units, an aeolian unit and a truncated soil, that suggest a distinct pedological modification and resulted in a soil sequence. All radiocarbon dates come from the soil horizons. The major pedogenetic reorganization occurred in the upper section of the sedimentary filling (stratigraphic units 2, 3, 4). The lowest layers (5 and 6) have been affected by the fluctuations of the water table. In these terms, reliable and rejected datings are discussed. The earliest occupations date from the Late Glacial interval, i.e., 15–10 ka BP. They occurred when the sedimentation event was dominant in the rockshelter; instead, the latest occupations (Early-Middle Holocene) occurred when soil forming processes were dominant. On the basis of the curve calibration and the subsequent calculation of the probability sum of the dates, this archaeological sequence allows us inferring that the human occupation of this locality started during Late Glacial times, toward the end of the Late Pleistocene. Between 11,000 and 9800 cal years BP a massive collapse of the roof of the rockshelter provoked the loss of its habitable surface. After that, the rockshelter was reoccupied by humans at the beginning of the Middle Holocene.