Rocks from the Rana Layered Intrusion usually have low concentrations of noble metals but have normal Ni and Cu concentrations. Consequently the rocks have higher Cu/Ir, Ni/Ir, Cu/Pb and Ni/Pd ratios than extrusive rocks from the literature. If a small amount of sulphide was removed from the magma prior to its emplacement at Rana the magma would be depleted in noble metals relative to Ni and Cu, and rocks forming from it would have high Ni and Cu to noble-metal ratios.
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