Application of lithogeochemistry in the assessment of nickel-sulphide potential in komatiite belts from northern Finland and Norway

Abstract

This study tests the application of chalcophile elements such as nickel, copper and the platinum-group elements as indicators of nickel-sulphide prospectivity in komatiites from terranes of the Karelian Craton in northern Finland and Norway. Major element abundances reflect volcanic processes associated with the emplacement dynamics of ultramafic lavas, whereas the variable chalcophile element concentrations record the ore-forming process, mainly as an anomalous metal depletion and enrichment relative to the calculated background. Geochemical data from this study indicate that Paleoproterozoic komatiites in the Pulju Greenstone Belts and Archean komatiites in the Enontekiö area are prospective for nickel-sulphide mineralisation. Conversely, on the basis of the present dataset, ultramafic rocks from the Palaeoproterozoic Karasjok Greenstone Belt display lower prospectivity for nickel-sulphides, although potential exists if high-volume flow conduits and channels within the large volcanic flow field could be identified.

Keywords

• nickel ores
• sulfides
• komatiite
• chalcophile elements
• ultramafics
• lithogeochemistry
• Paleoproterozoic
• Archean
• Finland
• Norway