Structural Setting and Controls on Ni-Cu Sulphide Mineralisation at Nova-Bollinger, Fraser Zone, WA

Abstract

Nova-Bollinger is a structurally modified magmatic Ni-Cu sulphide deposit in which sulphide melt was mechanically extracted from chonolithic intrusions and concentrated into structurally controlled positions within the footwall country rocks. The fertile intrusions were emplaced late during granulite facies high-temperature low-pressure (HT LP) metamorphism and deformation during Stage 1 of the Albany-Fraser Orogeny. Sulphide mineralisation, occurred initially as a magmatic melt and subsequently as a metamorphic modified melt that was mobilised along foliations and into F2 fold hinges, post-foliation pegmatites and a shear zone in footwall granulite gneisses. Disseminated and net-textured sulphide was retained within the chonoliths. The Nova-Bollinger system therefore represents an important example of a structurally modified magmatic Ni-Cu deposit.