Talc deposits in Norway
Information about talc and soapstone deposits registered in NGU's different databases and various available literature have been collected and described in the present report. Around 400 deposits/occurrences are known, but the detail of the available information varies widely. By reading old field-books as well as old manuscripts, maps, etc. dating as far back as A.D.1758, quite a lot of data has been found. The result of the work shows that most described talc in Norway is of ultramafic origin and is associated with serpentinites. The most common mineral association is talc + breunnerite. Different talc-provinces can be defined from the registered and non-registered data, the most important being Nord-Gudbrandsdalen, Altermark and Stølsheimen. While Altermark and Stølsheimen have been investgated in some detail with respect to talc as an industrial mineral, the Nord-Gudbrandsdalen talc province has been investigated both for milling talc and for soapstone use as dimension stone. Deposits that are probably extensive, but have so far not been investigated in detail, include the Lesjehorrungane deposits in the Nord-Gudbrandsdalen region and the Raudfjellet deposit in Nord-Trøndelag. The fractionated metakomatiites (pale green talc-chlorite rocks) of the southern part of the Palaeo-proterozoic Karasjok Greenstone Belt in Finnmark, Northern Norway, possibly represents, by far, the largest accumulations of talc in Norway. These rocks are recently mapped, for the first time, but other critical information is, however, very scarce.