Lake Boga Granite, northwestern Victoria: Mineralogy, geochemistry and geochronology

Abstract

The Devonian Lake Boga Granite in northern Victoria, while almost entirely under thin Murray Basin cover, is one of the largest plutons in the western Lachlan Fold Belt. Its only exposure is a quarry penetrating the Cenozoic sediments. In the quarry, prominent pod pegmatites and miarolitic cavities suggest a high level of emplacement. The granite, a non-magnetic, fractionated S-type, contains a large range of accessory minerals, including primary uranium- and REE-bearing phosphates and oxides, and primary copper sulfides. Monazite-series minerals show an exceptionally wide range of compositions, from normal monazite-(Ce) through cheralite (Ca-Th-rich) to rare huttonitic monazite (Th-rich) an..