Geochemical Atlas – Erzgebirge and Vogtland

Lanthanum (La) shows a log normal distribution with a slight tendency to left skew. The maximum value amounts to 280 mg/kg, the minimum to 4 mg/kg. The arithmetic average of 25 mg/kg exceeds only slightly the median of 22 mg/kg. An approx. 4 km area of La > 60 mg/kg is located west of the Augustusburg fluorite-baryte deposit at the northern rim of the study area. It represents the highest La concentration of relevant spatial extension within the study area and forms part of a 50 km NNE-SSW striking corridor with La > 32 mg/kg extending up to the region of Schwarzenberg. Besides lanthanum, it is also enriched in selenium and germanium. Areas of similar La concentrations are only found in the centre of the Kirchberg granite, at the concealed Eichigt granite and the Tharandt Volcanic Complex. Contents just above the arithmetic average (La > 25 mg/kg) cover the early Phanerozoic sediments and metasediments of most of the northern rim of the study area, as well as a ringshaped zone in the eastern Erzgebirge. The latter relates to the deposits of Zinnwald, Altenberg, Sadisdorf, Rehefeld and Moldava. This zone is similar to the distribution of beryllium. Though elevated La contents occur in relation to most of the magmatites, the Eibenstock pluton behaves the opposite way and hosts areas of minimum concentration with La < 6 mg/kg. The affinity to sediments and metasediments of Cambrian to Devonian age is a common trait of La together with cobalt, nickel, germanium and antimony.