The Relationship between Gabbros and Granites in the Lachlan Fold Belt: An example from Arte River, East Gippsland

Abstract

The Arte River Gabbroic Complex is located in eastern Victoria within the Kuark Metamorphic Belt. It is spatially associated with a number of I-type granites, the A-type Murrungowar adamellite and the Scrubby Flat Gabbroic intrusion located further to the north. These are hornblende orthopyroxene gabbros, with two samples containing titanaugite. Geochemical analyses reveal two distinct magma types in the Arte Gabbroic complex an alkali component, evident in the pyroxene mineralogy, and a tholeiitic component. The complex is associated with a small tonalite/diorite lens with complex but sharp boundaries between the two. Sr-Nd isotope studies reveal two evolutionary arrays, one between this lens and the alkali component and the other between the thoeleiitic and the Scrubby Flat Gabbro located to the north-west of the main Arte River gabbro intrusion.