Grant: Discovery Grants Program - Individual

OBJECTIVE: My discovery grant will concentrate on understanding the processes leading to the formation of magmatic platinum-group element (PGE) and nickel (Ni) deposits. In particular I would like to consider the processes leading to the formation of the phases hosting these elements. METHODOLOGY: The following projects are proposed: a) The classical model suggests that these elements are collected from mafic magma by a base metal sulphide (BMS) liquid and that saturation of the magma in BMS liquid is brought about by contamination with a sulphur-bearing sediment. We would like to look for evidence of the sediments by looking at trace elements in BMS. b) Saturation of mafic magmas with an Fe-sulphide liquid has been investigated, but whether Ni and Cu concentrations in mafic magmas affect how much sulphur is required to saturate a magma has not. We would like to carry out experiments to investigate this. c) Some workers propose that in PGE-deposits BMS is not the main collector of PGE and that PGE were collected or redistributed by late magmatic or metamorphic processes. We wish to investigate this idea by determining which minerals host PGE in Ni- and PGE- deposits and what the textural relationships of these minerals are in deposits that have undergone different degrees of metamorphism and high temperature alteration. d) Investigate the influence of metamorphism and high temperature alteration using S/Se ratios e) Some models suggest that magma mixing is important in the formation of PGE deposits. We will look for evidence of magma mixing by considering the trace element contents of silicate minerals associated with the deposits. INNOVATION: These projects will apply the newly developed LA-ICP-MS and micro petrographic techniques that have to date been largely reserved for fundamental research to the realm of ore-deposit formation.