Geochronological, stable isotopes and fluid inclusion constraints for a premetamorphic development of the intrusive-hosted Bjorkdal Au deposit, northern Sweden
2009 (English)In: International journal of earth sciences, ISSN 1437-3254, E-ISSN 1437-3262, Vol. 98, no 5, 1027-1052 p.Article in journal (Refereed) Published
The Bjorkdal gold deposit, bound to a quartz vein system which is mainly hosted by a quartz-monzodioritic intrusion, is situated at the easternmost part of the 1.9 Ga Skellefte base metal district in the Fennoscandian shield. Three fluid stages may be distinguished, referred to as a ""barren"" stage, a main gold stage, and a remobilization stage, respectively. From oxygen and hydrogen isotope evidence, it is argued that fluids of different origins (magmatic and surface waters) penetrated the ore zone at the inferred stages, but regional metamorphic fluids appear essentially only to have redistributed elements. Early quartz veining took place during a pre-metamorphic stage at ca. 1.88 Ga, as evidenced by unradiogenic galena data and an Sm-Nd scheelite errorchron of 1,915 +/- A 32 Ma (MSWD = 0.25). Temporarily, the main ore-forming stage was closely related to the first barren stage and took place during a major uplift event close to 1.88 Ga. Although other source rocks cannot be totally ruled out, available isotope data (O, S, Sr and Pb) are seemingly consistent with the view that these elements, and by inference other ore elements, were derived from the host intrusion.
Place, publisher, year, edition, pages
2009. Vol. 98, no 5, 1027-1052 p.
Au ore, Quartz lode, Skellefte district, Fennoscandian shield, Isotopes, Fluid evolution
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:su:diva-60071DOI: 10.1007/s00531-008-0301-8ISI: 000266911100005OAI: oai:DiVA.org:su-60071DiVA: diva2:433131
authorCount :62011-08-092011-08-082011-08-09Bibliographically approved