Application of lithogeochemical and pyrite trace element data for the determination of vectors to ore in the Raja Au–Co prospect, northern Finland

Abstract. Discovering ore deposits is becoming increasingly difficult, and this particularly true in areas of glaciated terrains. As a potential exploration tool for such terrains, we test the vectoring capacities trace element sulfur isotope characteristics pyrite, combined with quantitative statistical methods whole-rock geochemical datasets. Our target Rajapalot gold–cobalt project northern Finland, where metamorphosed Paleoproterozoic volcanic sedimentary rocks Peräpohja belt host recently discovered gold prospects, which also have significant cobalt enrichment. The focus put on single prospect, known as Raja, an excellent example unusual cobalt-enriched deposit, common terranes Finland. major lithologies at comprise amphibolite facies polydeformed calcsilicate that alternate albitic units, mafic rocks, mica schist quartzite. Mineralization prospects characterized by older Co-mineralizing event younger high-grade Au mineralization re-mobilization re-deposition Co. Detailed situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) powerful technique produces robust databases from paragenetically texturally well-characterized pyrite Raja prospect. results are treated appropriate log-ratio transformations used multivariate data analysis, computation principal components. Application these revealed elements Co, Ni, Cu, Au, As, Ag, Mo, Bi, Te, Se, Sn, U, Tl W high to discriminate between Co-only Au–Co zones, well stages. systematic study suggests homogenous isotopic (+1.3 ‰ +5.9 ‰) positive loadings Bi onto PC1 reflective early stage Co mineralization, while opposing negative W, Tl, Cu Ag along associated pyrites Au-mineralizing event. signature latter type −1.2 +7.4 ‰. Subtle patterns recognized geochemistry favor As–Au–Se–Te–W–U axis localization whereas group Se has PC2, will predict zones. This shows efficiency mineral targeting, capacity define future targets characterizing metallogenic rock, distinguishing various stages mineralization.