On the role of metamorphism in the formation of nickel-copper sulphide deposits in the Kola peninsula.

Abstract

There are three stages in the formation of these deposits: 1) magmatic, when syngenetic ores are simple and of constant composition; 2) regional metamorphic, with epigenetic ores of varying composition, and 3) late metamorphic, confined to local tectonic zones and with varying mineral assemblages. The more the mineral composition of an ore changes, the less its geochemical characteristics differ from others and vice versa. All metamorphic alteration events took place within the primary orebodies and so the Ni-Cu sulphide deposits of the region can be classed as metamorphosed magmatic deposits.-R.E.S.