Geoarchaeological and pedostratigraphic study of the San Michele Cave of Saracena, Calabria, southern Italy: reconstruction of late Pleistocene to mid-Holocene paleoenvironmental changes

The San Michele Cave is an open hypogeal karst landform shaped in the dolostone-limestone bedrock of the Pollino Massif close to Saracena, in north Calabria (southern Italy). It was repeatedly settled and abandoned by men since Palaeolithic to Early Bronze Age. We focused on reconstruction of late Pleistocene to mid-Holocene paleoenvironmental changes recorded in the pedosedimentary infilling of the cave. We applied a multidisciplinary approach, based on geomorphological, pedological, geochemical and micromorphological analyses. Various stages of geomorphic stability and pedogenesis (with dominant humus accumulation, carbonate leaching and reprecipitation) alternated with sedimentary phases, which mainly emplaced thin-layered, (sandy-)loam deposits, with occasional very coarse debris related to rock-fall processes from the roof. Also important reworking processes from outside and/or inside the cave are evidenced by siliciclastic sediments, pedorelicts and/or papules, easily detected at the microscale in soil thin sections. Chronological constraints, obtained on the basis of archaeological findings and radiocarbon dates of charcoal fragments at different stratigraphic heights, permitted us to estimate approximate rates of sedimentary aggradation and soil formation. Moreover, the main soil features (e.g. CaCO3 concretions, clay coatings or papules) and pedogenic iron indices were interpreted as indicators of the local response of pedogenetic processes, weathering degree and geomorphic dynamics to climatic changes, which presumably also interacted with effects of human activities both in the cave and in the surrounding external environment.