Geology of the Fäbodliden C lode gold deposit in northern Sweden: Implications for Gold Process Mineralogy
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
The Fäbodliden C lode gold deposit is located in the Vindelgransele area, in the westernmost part of the well-known Skellefte District, bordering to the Gold Line District, in northern Sweden. The geology of the deposit consists of a massive quartz vein hosted by a sequence of turbiditic greywackes and pelitic sediments and situated some 20 to 30 meters above the contact to an elongated granodioritic sill. All rocks have been affected to various extents by the regional metamorphism into greenschist facies. The quartz vein is rich in Au and Ag but also shows high concentrations in Zn, As, Cu and Pb. The granodiorite is intermediate, oversaturated with respect to silica and peraluminous, has a subalkaline magmatic affinity and shows volcanic arc settings. The hydrothermal alteration is characterized by strong sericitization and chloritization enveloping the mineralized quartz vein with no obvious defined lateral zonation. Gold is mainly hosted by the quartz vein but some is disseminated in the granodiorite. Gold-containing minerals are dominantly electrum which exhibits a median purity of 770 fine. The grain size ranges from coarse- grained to very fine-grained. Gold is commonly associated with sulphides, including at grain boundary to- or as inclusion in arsenopyrite, pyrite, pyrrhotite, chalcopyrite, galena and sphalerite. Arsenic, Sb, Bi and Ag are significantly correlated to Au. Gold being mainly quartz vein-hosted, the mineralization should be relatively easy to treat during mineral processing. Over 90 % of gold should be recovered using gravity separation followed be a direct cyanide leaching. Some deleterious mineralogical factors (e.g. gold-containing mineralogy, gold grain size and sulphide association) could however affect the efficiency of the recovery process. According to the geology, the chemical and mineralogical characteristics of the rocks and the hydrothermal alteration, genetically, the deposit should be classified as an orogenic gold deposit, in the sense of Groves et al. (1998), even though the classification is based on rather limited data.
Place, publisher, year, edition, pages
2015. , 34 p.
Technology, Fäbodliden C, Northern Sweden, Gold, Geology, Geochemistry, Hydrothermal alteration, Process mineralogy
IdentifiersURN: urn:nbn:se:ltu:diva-58250Local ID: ed3b9e5c-db47-4458-9d1b-bc19d7dd4567OAI: oai:DiVA.org:ltu-58250DiVA: diva2:1031638
Subject / course
Student thesis, at least 30 credits
Geosciences, master's level
Validerat; 20150401 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved