De prekambriske bergarter i Telemark, I. Gruber og skjerp innen gradeteigkart E36V Kviteseid.

Abstract

Approximately 115 mines and claims have been examined in the years 1941-1961 during regional geological mapping of the Kviteseid quadrangle. The map area covers a part of the \"Thelemark-Sætersdal ore province\" established by prof. J.H.L. Vogt in 1886. The oldest mine in the area, opened in the year 1524, was worked for silver bearing chalcopyrite and bornite. Other mines have been worked for gold, native copper and silver, molybdenite, galena, arsenopyrite, bismuthinite. All the mines have long since been abandoned and most of the surface workings are overgrown and difficult to find. The 15 native copper and silver deposits (which also contain vanadium minerals) form a separate group. They are all situated along the contact between a sandstone and an overlying basalt, the ore being confined to the sandstone. Most of the other deposits are of Quartz vein type. In quartzites which cover the greatest part of the map area, most of the quartz veins are barren. The great abundance of ore minerals in quartz veins in basic lavas and basic sills may be due to favourable pH conditions in these rocks. The galena deposits are found within a limited area close to a penetrating granite. The ore mineral paragenese in some of the deposits may have been formed under hypothermal to mesothermal conditions whereas other possibly originated at lower temperatures.