Abstract
Grundfors is a quartz vein related gold deposit in the eastern part of the Skellefte district in northern Sweden. The gold occurs both alone and together with arsenopyrite in second generation quartz veins, and as impregnations in the host rock adjacent to these veins. The NE striking, en échelon quartz veins lie in approximately N striking zones in a folded sequence of volcanogenic metasedimentary rocks and metamorphosed tuffs. The gold bearing quartz veins were introduced late during or after the second deformation which produced close to tight folds with a subvertical NNW striking axial plane and fold axes plunging 65° SE. The zones with quartz veins strike parallel to, and are sometimes coincident with, faults interpreted from a ground magnetic map.