Mineralogy of the Murrin Murrin Nickel Laterites

Nickel and cobalt mineralisation at the Murrin Murrin deposits, in the North Eastern Goldfields region of Western Australia, occurs within laterites developed on Archaean serpentinised peridotite units. Lateritic weathering of the peridotite has produced a resource of 116.8 Mt at 1.10 per cent Ni and 0.082 per cent Co (resource at May 1996 with a 0.8 per cent Ni cut-off; see Fazakerley and Monti, this volume). The mineralogy of the Murrin Murrin laterites was investigated to identify the minerals hosting significant Ni mineralisation. Laterite profiles were studied using X-ray Diffraction (XRD), impregnated polished thin sections, and Energy Dispersive Spectroscopy (EDS) Electron Microprobe analysis, of RC percussion drill chips. This paper summarises the results of these studies, and briefly discusses the nature of the minerals hosting Ni mineralisation.