Mineralogy,geochemistry and ore potential of an ultramafic rock from the Kvaløya Island.

Abstract

A low-grade metamorphic ultramafic rock at the Kvaløya Island, North Norway, shows Ni content up to 2 500 ppm. Olivine is absent from the rock, and Ni is principally bonded in pentlandite, violarite and millerite. Among other sulphide minerals found in the rock are pyrite, pyrrhotite, chalcopyrite, sphalerite, galena and heazlewoodite (?). Two generations of pyrite are observed in the rock. Second generation is Ni-rich. The rock represents a zone of supergene alteration. The rock was most likely formed in the intracontinental environment. The serpentinized ultramafic rock from the Kvaløya Island can be an example of low-grade Ni-ore if integrated approach is used for waste minerals. One possible use of many of the traditional waste materials from mining is for CO2 sequestration, i.e. by reacting the waste minerals with CO2 in order to permanently store CO2 in carbonates. In this work we present an overview of sulphide mineral content, data on conditions of sulphides formation along with geochemical investigations and some constraints on tectonic settings of the rock.