Broken Hill — A Precambrian hot spot?

Studies on the variations of metamorphism in the Precambrian granulite facies terrain of Broken Hill has revealed that these high-grade rocks are most frequently found in an elliptical zone known as the Broken Hill Basin. The density distribution of these granulite facies rocks, together with their lithological—structural—geophysical—mineralization relationships suggest local conditions of high-grade metamorphism. Several models to account for these observations are possible including lithological, structural-stratigraphic and mineralization controls. However in the light of current views of plate tectonics, a crustal-spreading hot spot model should also be seriously considered. The association of high-grade metamorphism and Broken Hill type mineralization is thought to be significant and this relationship could be applied in the search for ore deposits.