A scheelite mineralization in calc-silicate rocks of the Moldanubicum (Bohemian Massif) in Austria

In the Moldanubicum (Bohemian Massif) of Austria a tungsten mineralization bound to calc-silicate rocks was discovered in the so-called Bunte Serie, a metasedimentary geologic unit now in amphibolite to higher amphibolite facies. The main constituents of the scheelite-bearing rocks are ferro-salite, meionite-rich scapolite, and quartz. The average tungsten content is estimated to be 1500 ppm; no further elements that would be characteristic for an exoskarn formation are enriched conspicuously. The whole series of calc-silicate rocks is intercalated in sillimanite gneisses. This series could be traced for about 5 km. The mineralization seems to be strata-bound — contacts with intrusive rocks were not observed. The field evidence is, therefore, easiest to reconcile with a synsedimentary origin, but the geology of the region is not known in sufficient detail to make this interpretation conclusive.