Original paper
Sveconorwegian polymetallic quartz veins in Sweden
Alm, E.; Sunblad, K.
Neues Jahrbuch für Mineralogie - Monatshefte Jg. 1994 Heft 1 (1994), p. 1 - 22
48 references
published: Feb 7, 1994
ArtNo. ESP156199401001, Price: 19.00 €
Abstract
A widely distributed system of partly gold-bearing polymetallic quartz veins occurs in the Southwest Scandinavian Domain of the Fennoscandian Shield. The veins are localized to the west of the Mylonite Zone, with the majority forming a belt extending from lake Mjøsa, southeastern Norway, to lake Vänern, southwestern Sweden. Granitoids, gneisses and metasediments with ages of c. 1.6-1.1 Ga constitute the host rocks for the investigated veins, which display cross-cutting relationships relative to these rocks and are inferred to be of Sveconorwegian origin, i. e. around 0.9 Ga old. The veins show variable chemical and mineralogical compositions and four types can be distinguished: Cu-dominated veins with chalcopyrite and/or bornite; Pb-Cu-bearing veins with pyrite as well as occasional galena and chalcopyrite; Zn-Pb-dominated veins with sphalerite and galena as well as occasional pyrite and chalcopyrite; Mnbearing vein (s) with galena, chalcopyrite and hausmannite. In addition, native gold and a number of rare minerals including argyrodite, hessite, tellurobismuthite and altaite are present, preferently in the two first mentioned types. The ore lead isotopic composition is more complex than previously reported and two separate source rock systems appear to have contributed to the vein deposits. One system was responsible for the complex metalliferous veins in Dalsland and westernmost Värmland, whereas the other system was responsible for the veins in the Värmskog area. In spite of the chemical, mineralogical and isotopic variations recognized, overlapping characteristics between the vein types do exist and a common origin in general is envisaged for all veins.
Keywords
Sveconorwegian • SW Sweden • polymetallic • quartz veins • ore petrology • geochemistry • lead isotopes