Sandån, Stulen, Skien, Telemark, Norway

Several small prospects and veins in the area. The small river Sandåen follow the fault between precambrian basement, consisting of granitic-gneiss and granitic-pegmatites and the Oslo-graben, consisting of cambrian-silurian sediments. This fault is going in NW-SE direction, with basement as foot-wall and Oslo-graben as hanging-wall. The quartz-fluorite veins are all related to the fault.

Ref:
Larsen, A.O. (1993): "Gruver og skjerp i Skien" ("Mines and prospects in Skien"), pp 50-52.