W and V mineralization in Langban-type Fe-Mn deposits: Epigenetic or syngenetic?

New observations of minerals rich in W and V at the carbonate-hosted Langba n-type Fe-Mn-(Ba-As-Pb-Sb) deposits in the Bergslagen region, Sweden, have been made. Scheelite with variable but high Mo contents (up to 40 mol.% pow ellite) commonly occurs in the hematite-quartz ores. Crystals of welinite, found in vein assemblages (Langban, Sjogruvan) and in Mn skarn matrices (Sj ogruvan) , are often complexly zoned and display some solid solution toward s the Sb-Fe counter-part orebroite. Manganberzeliite containing up to 20 mo l.% of its vanadate analogue (palenzonaite) in solid solution has been reco rded from the Jakobsberg deposit. In contrast to previous assumptions, ther e appears to be no genetic link between local granitic rocks and the W mine rals. W, as well as V, is inferred to be syngenetic with Fe and Mn at these deposits.