Mineral characterisation and i
gneous petrology by LA-ICP-MS

Dr. Christian Tegner, NGU, Norway

A study of trace element composition in 20-30 micron spots of selected silicate and oxide minerals will be carried out using the laser ablation ICP-MS facility at NGU. This geochemical investigation will firstly better characterise investigated rock and ore types and secondly throw direct light on the compositional evolution of the magma (using mineral-melt partitioning coefficients) from which the minerals crystallised. This study will build on previous studies and key samples of Robins, Wilson, Schiellerup and others, as well as new samples, in a collaborative network between Aarhus (DK), Trondheim (NO) and Bergen (NO) universities and NGU. Study targets will include: 1) plagioclase and pyroxene in representative samples within the anorthosite complexes including labradorescent leuconorite presently mined as dimension stone; 2) ilmenite of the Telnes intrusion; 3) pyroxene and plagioclase in selected samples spanning the most primitive (ilmenite-bearing) to the most evolved (apatite-bearing) cumulate rocks of the Bjerkreim-Sokndal intrusion and its chilled margins.