Some new constraints on hydrothermal alteration and deformation of the Paleoproterozoic serpentinite-hosted Outokumpu Cu-Co-Ni-Zn-Au deposits, Finland

Abstract

Although the Outokumpu ore deposit has been long regarded as having affinities with ocean floor exhalative deposits, recent studies have shown that the host serpentinites are depleted mantle harzburgites and that the putative silicous exhalites are in fact leached serpentinite. The intense structural reworking and metamorphic overprint precludes further assessment of the original nature of the Cu enrichment, although limited Pb isotope data militate against an interaction with continental crust.