Vol. 30 No.1 March 2007

Journal of International Geoscience

Published by the International Union of Geological Sciences

by Franco Pirajno

Mantle plumes, associated intraplate tectonomagmatic processes and ore systems

Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia. E-mail: franco.pirajno@doir.wa.gov.au

Abstract

Intraplate tectonic and magmatic phenomena are linked to deep mantle plumes and asthenospheric upwellings. Resulting magmas, which include layered mafic-ultramafic intrusions, sill complexes, continental and oceanic flood lavas, giant dyke swarms and anorogenic A-type granitic rocks, are responsible, directly or indirectly, for a large number of intraplate and anorogenic ore systems. These ore systems can be considered in terms of 1) magma-associated, such as orthomagmatic Ni-Cu- PGE, Cr in mafic-ultramafic rocks and magmatichydrothermal ore systems in anorogenic A-type magmas (e. g. greisen Sn-W, Fe oxide-Cu-Au); and 2) hydrothermal systems powered by the large thermal energy that results from the emplacement of plume-derived melts into the crust. These hydrothermal ore systems include low-S epithermal, porphyry, VMS and Carlin style deposits.

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