Abstract
The occurrence, structure and metamorphic history of the Glenorchy scheelite deposits and the surrounding schists have been studied. Petrographic descriptions of the schists, quartz veins and scheelite -bearing lodes are given, the relation of the lode minerals described and a sequence of mineralisation stated. The present steep dip of the schists to the west, the main joint system and the presence of small almost parallel veins are ascribed to a tilting movement later than the main metamorphism and contemporaneous with the Hokonui Lower Cretaceousorogeny. The genesis of the scheelite is discussed, a magmatic origin being favoured and the lodes regarded as mesothermal deposits formed in the late Palaeozoic period. Qualitative chemical and fluorescence tests of the scheelite are given while an appendix contains a description of special methods used in the investigation.