Geochemistry of Archaean Volcanic Belts in the Eastern Goldfields Region of Western Australia

Abstract

Volcanic belts in the Kalgoorlie-Norseman district of the Eastern Goldfields region of the Western Australian Shield are dominated by monotonous sequences of metamorphosed tholeiitic pillow basalts showing little vertical or lateral variation. These meta-basalts are chemically similar to Archaean tholeiites from Canada and South Africa and are characterized by their low content of K, Rb, and Sr and low Fe₂O₂/FeO ratios. There is little evidence of major cyclic compositional trends within the volcanic belts, with both major and trace elements showing limited dispersion. An undifferentiated, uncontaminated source of basaltic material was available throughout the development of thick volcanic piles in the region.