Geochemical Atlas – Erzgebirge and Vogtland

The distribution of Selenium (Se) is nearly log normal. With an absolute maximum of 15 mg/kg and a minimum of 0.1 mg/kg, it is a scarce element and does not show strong contrasts within the study area. The arithmetic average of 0.88 mg/kg is slightly higher than the median of 0.80 mg/kg. Selenium exhibits spot-like enrichments across the study area, the strongest of which is a circular area in Ordovician metapelites and siliceous shales east of Adorf in the southwestern part of the study area. It is represented by a core area of Se > 2.5 mg/kg coinciding with elevated levels of other elements, among which molybdenum is the most important. About 8 km northeast of the latter area, the baryte and U deposits of Brunndöbra and Schneckenstein together with the Gottesberg Sn-greisen district coincide with a spot of Se > 1.6 mg/kg. Another area of 3.5 km diametre and similar concentration is located in Silurian and Ordovician metapelites at the eastern part of Lößnitz-Zwönitz syncline. Further northeast, the central Freiberg district and the area NW of the Augustusburg fluorite-baryte deposit show elevated Se. Lower concentrations of Se > 1 mg/kg form areas connecting the spots of Thum and Augustusburg via a NNE striking corridor following the eastern limit of Ordovician metasediments west of the Neoproterozoic gneisses of the eastern Erzgebirge. Selenium coincides here with elevated lanthanum and germanium. An area of similar NNE strike borders the western edge of the study area in Ordovician and Devonian sedimentary and volcanic rocks. Other areas of elevated concentration are arranged as a chain in the eastern Erzgebirge between the mining districts of Freiberg North and Altenberg. This zone is co-enriched with several other metals such as bismuth.