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Classification of Ni Cu deposits. From Naldrett , 2004. Komatiite definition. A simple definition is a komatiite is an ultramafic lava flow. It has textures indicative of quenching. Associated basalts may be called komatiitic basalts. Guilbert and Park, 1986. From Evans, 1993
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Classification of Ni Cu deposits From Naldrett, 2004
Komatiite definition • A simple definition is a komatiite is an ultramafic lava flow. It has textures indicative of quenching. Associated basalts may be called komatiitic basalts.
From Evans, 1993 KambaldavsPerserverence
It is a fault bounded rift zone about 200 km wide. There are 2 volcanic cycles, each consisting of a lower ultramafic series, an intermediate felsic volcanic series and topped by sedimentary rocks derived from the mafic rocks. All important deposits occur in the lower ultramafic rocks of the oldest series, about 2700 Ma old. There has been recumbent folding in the area and all ore deposits are have been metamorphosed and complexly deformed. They are in the amphibolitefacies. The overall structure in the area consists of a series of domes and basins and the deposits are located around the periphery of granitoid bodies
Grades of deposits Volcanic type: 1 to 5 MT with grades of 1.5 to 3.5% Ni Dyke or sill: 100-290 mT with av. grade of 0.6% Ni
Principle ore minerals in decreasing amount are: • Pyrrhotite • Pendlandite • Pyrite • Oxides (mt and chr) • Chalcopyrite • Millerite • Violarite • ?are they all stable together?
Classification of Ni Cu deposits From Naldrett, 2004
Going to Jim Miller’s Web page http://www.d.umn.edu/~mille066/Teaching/DCsem.html