Platinum-group mineralization in the Tertiary Igneous Province: new data from Mull and Skye, Scottish Inner Hebrides, UK

In recent years, platinum-group mineral deposits have been reported from several of the Tertiary igneous complexes in East Greenland. These intrusions form part of the same igneous province as the Tertiary igneous centres in northwest Scotland, and recent work confirmed the presence of abundant platinum-group minerals in the Rum Central Complex. In this paper we report for the first time the presence of abundant and diverse platinum-group minerals from the Tertiary Pen Buie intrusion on Mull and the Cuillin Complex of Skye, Inner Hebrides, Scotland. The platinum-group minerals in the Ben Buie intrusion are associated with chromitite layers in ultramafic cumulates. The grains are small (1-2 mum), locally very abundant, and dominated by Pd-Bi-Te-Sb phases. In the Peridotite Series of the Cuillin Complex, the platinum-group minerals are dominated by laurite commonly enclosed within chromite or silicate. A combined orthomagmatic-hydromagmatic origin is proposed for the mineralization. However, the style and type of mineralization differs between each of the igneous centres. Platinum-group element mineralization is a ubiquitous feature of the Tertiary Igneous Province in northwest Scotland and in Greenland and is intimately linked to the regional tectonic setting.