Soil pollen analysis of a podsol and a clearance cairn confirms Bronze Age agriculture at Orstad, south-western Norway

Abstract

Archaeological investigations, soil pollen analyses, and 14C-dating in a field rich in clearance cairns at Orstad, southwestern Norway, gave evidence of human activity extending back to the Late Neolithic period and/or Early Bronze Age. Pollen of Triticum type confirmed agriculture on the site. In this case study, pedo-stratigraphic and pollen-stratigraphic results from two soil profiles made it possible to reconstruct three stages of the very local palaeoenvironment at the two neighbouring sites, and gave evidence for one phase of cultivation. Hyphae analysis suggested that the soil was in a brown earth stage, when people began to cultivate it, probably between 2120–1675 cal BC. A comparison of the pollen distributions in the two profiles shows evidence of pollen translocation. The study confirms the archaeological correlation of a layer in the soil under the investigated clearance cairn with a layer in the profile of a surrounding podsol, although 14C-dates from the two layers differ. Uncertainties in the records from mineral soils related to soil disturbance, soil development, pollen destruction and pollen translocation can be compensated for by the complementary information from profiles of different types from the same site.