Ash and metal concentrations in peat bogs as indicators of anthropogenic activity

Stratigraphical (temporal) and physicochemical investigations of different European peat bogs confirm interrelations between increased ash and element concentrations on the one hand and human settlement (found by means of pollen analysis) on the other hand. Phases of enhanced anthropogenic activities (farming, forest clearing, forestry etc.), which can be derived from the corresponding pollen diagrams and by radiocarbon dating, agree well with the increase in soilborne elements (soil dust Pb, Si, Ti) in the peat profiles. The Pb concentrations of the investigated peat layers have been increasing since Roman Times. Changes in the Pb/Ti ratio help to discriminate between soil dust Pb and Pb from ore mining and smelting. Moreover, this approach reveals measurable Pb pollution extending as far back as the Bronze Age (approx. 2(nd) Millenium B.C.). Some peat bogs show increased Cu concentrations as far back as the Bronze Age.