Geological factors influencing the concentration of trace elements in the Philippi peatland, eastern Macedonia, Greece

Six peat samples obtained from the Holocene and the Weichselian of the Philippi peat deposit, eastern Macedonia, Greece, were analyzed for 48 trace elements by Inductively Coupled Plasma–Mass Spectrometry (ICP–MS). The ash contents of these samples were also determined. Most of the trace elements are associated with the minerals in the peat, while Ge, Mo, Pb, Se, Ta, Tl, U, and W display a greater affinity with the organic matter. Compared with crustal averages (Clarke concentrations), the Philippi peat is enriched in some elements (Ag, As, Au, Cd, Mo, Se, Te, U, and W) because of the respective mineralizations in the area. The Philippi peat is also enriched in Cr, Cu, Mo, Pb, Sc, Sn, T, V, Y, and Zn in comparison with typical fen peats, as well as in As, Cr, Mo, Se, and U in comparison with typical coals. Climatic and hydrogeological conditions strongly influenced the peat-forming environment resulting in a differentiation between Holocene and Weichselian peat. Generally, the Holocene peat contains lower concentrations of trace elements in the northern and southern part of the fen, than the Weichselian one. The opposite trend is observed in the fen area close to the western basin margins.