Granite-greenstone connection in western Victoria: An example from the Bushy Creek Igneous Complex

Abstract

The Bushy Creek Igneous Complex includes rock types ranging from greenstone through diorite, granodiorite and granite to aplite and was emplaced in the Grampians-Stavely Zone 30 km southeast of the Grampians Ranges at ca 495 Ma. Striking correlations with varying silica contents are observed in major- and trace-element abundances which, coupled with a close spatial and temporal association, suggests a strong petrogenetic link between all rock types. It is proposed that these trends reflect the operation of fractional crystallisation processes dominated by hornblende (and/or clinopyroxene) and plagioclase at lower silica levels, changing to an assemblage dominated by plagioclase and accessory..