Mineralogical, lithogeochemical and sulfide trace element characteristics of the Hirvilavanmaa Au-only and the base metal-rich Naakenavaara orogenic gold deposits in the Central Lapland belt, northern Finland

Building Geochemical Vectors with Trace Element Compositions of Sulfides in Orogenic Gold Mineral Systems in Northern Finland

“…Central Lapland Greenstone Belt: Sulfide trace element analyses from Hirvilavanmaa and Naakenavaara cover 17 samples from each deposit (drill cores: R325B, R335, R395 and R611, R617, R618, respectively). For a detailed description on the mineralogical, lithogeochemical und sulfide trace elemental characterization of these samples, the reader is referred to Vasilopoulos et al (2023). Sulfide trace element analyses from Iso-Kuotko samples cover mineralized and barren sections along five drill cores (ISO 12010 drill hole, Kati orebody; ISO 08004, ISO 08011 and R-312 drill holes, Retu orebody; and R-452 drill hole, Tiira orebody).…”

“…3b) is located in the southern part of the CLGB (Savukoski group), 15 km northeast from Kittilä town, at the intersection of the EW-trending SiSZ and the NS-trending KiSZ (Hulkki and Keinänen, 2007;Rupert Resources, 2020). At Hirvilavanmaa the 270 × 90 m large, NNE-trending mineralized domain is hosted by chlorite-albite-carbonate-altered ultramafic rocks within a multi-phase stockwork of early carbonate veins, and late quartz-carbonate veins and quartz-dominant (±tourmaline) veins that host most of the mineralization (Hulkki and Keinänen, 2007;Rupert Resources, 2020;Vasilopoulos et al, 2023). The younger auriferous quartz-veins are pyrite-rich, and gold mineralization occurs as small inclusion of native gold in pyrite or as fracture-filling components (along with chalcopyrite and carbonate) in the pyrite host (Hulkki and Vasilopoulos et al, 2023).…”

“…The Naakenavaara area is situated along the northern limb of the Naakenavaara syncline, where the bulk of mineralization occurs within a parasitic drag fold (Taranis Resources Inc, 2013). Mineralization is hosted by albitized graphitic phyllite (near a komatiite unit), and albite-quartz-carbonate veins (Keinänen, 2002;Vasilopoulos et al, 2023). The main ore minerals are pyrite, pyrrhotite and chalcopyrite.…”

“…The sulfide trace elements collected from deposits within the Finnish orogenic gold and battery metal mineral systems, allow us to characterize the underlying bedrock, the mineralization types, as well as the metallogenic context of the region (see Molnár et al, 2017Molnár et al, , 2019Vasilopoulos et al, 2021Vasilopoulos et al, , 2023Raič et al, 2022). In addition, it permits the discrimination between deposit types and gold ores, making it eligible for a potential reference dataset used in the indicator mineral approach.…”

“…The efficiency of pyrite trace element geochemistry in mineral exploration targeting has been recently tested by several research groups working in selected deposits within the metamorphosed terranes in northern Finland (Molnár et al, 2017;Ranta et al, 2018;Raič et al, 2022;Vasilopoulos et al, 2021Vasilopoulos et al, , 2023. From these local-scale studies, the authors conclude that the approach of trace elements of heavy minerals has the capacity to distinguish mineralization stages and characterize the metallogenic potential of the host rocks with a particular set of elements (e.g., Co, Ni, Cu, Au, As, Ag, Mo, Bi, Te, Se, Sn, U, Tl and W, see Raič et al, 2022).…”