Geochemical Atlas – Erzgebirge and Vogtland

The Molybdenum (Mo) distribution is log normal with an arithmetic average of 1.1 mg/kg, a median of 0.7 mg/kg, a maximum of 120 mg/kg and a minimum of 0.05 mg/kg. Elevated Mo contents occur in relation to both acidic magmatites and Ordovician through Devonian sedimentary and metasedimentary rocks. Areas with Mo > 4 mg/kg were predominantly detected in the eastern Erzgebirge, including the Altenberg-Zinnwald greisen district and adjacent greisen deposits further north like the Sadisdorf Sn-Cu deposit. Here, the Mo was recovered as a by-product from local Sn production. In the western Erzgebirge, the only region with similar Mo levels is within a circular area east of Adorf where Ordovician metapelites and siliceous shales occur. Apart from this, only smaller spots of elevated Mo were detected across the Vogtland area concentrated in its northern parts. Concentrations of Mo > 2.5 mg/kg characterise the Markersbach granite in the eastern Erzgebirge. Levels of Mo > 1.6 mg/kg predominate in the Schneeberg and Bad Schlema-Alberoda BiCoNi districts, in Silurian metapelites of the LössnitzZwönitz Syncline, and along the western rim of the study area related to Devonian sediments and volcanics. Contents of Mo > 1 mg/kg form a corridor between Freiberg and Altenberg with an orthogonal branch between Freiberg, the Mohorn-Grund deposit, and the northern tip of the working area. Similar contents occur in shales of the NW-SE trending Ordovician to Carboniferous syncline NW of the Markersbach granite. Finally, the lowest contents of Mo < 0.25 mg/kg occur in gneisses of the eastern Central Erzgebirge, at the western Eibenstock granite, and in Cambro-Ordovician metapelites around Adorf.