Intrusive history and volatile evolution of the Endeavour porphyry Cu-Au deposits, Goonumbla district, NSW, Australia ...

• Main Author: Lickfold, V
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: Endeavour; Macquarie Island
• Online Access: https://dx.doi.org/10.25959/23210837; https://figshare.utas.edu.au/articles/thesis/Intrusive_history_and_volatile_evolution_of_the_Endeavour_porphyry_Cu-Au_deposits_Goonumbla_district_NSW_Australia/23210837

The Goonumbla Volcanic Complex (GVC) of central-west New South Wales, Australia, is part of the Ordovician Macquarie Island Arc. The upper unit of the GVC, the Wombin Volcanics, comprises submarine shoshonitic lavas and associated volcaniclastic rocks, and hosts four economic porphyry Cu-Au deposits, Endeavour 22 (E22), E26, E27 and E48. Together these deposits have a combined ore reserve of 63.6Mt @ 1.1 % Cu and 0.5g/t Au. Mineralisation is centred on thin, pipe-like quartz monzonite porphyry (QMP) complexes that intruded the Wombin Volcanics in an extensional regime towards the end of the Late Ordovician. Despite being some of the smallest economic porphyry deposits in the world in terms of tonnage and cross-sectional area, detailed pit mapping and drillcore logging has led to the recognition of eight intrusive phases within the QMP complexes of the Endeavour deposits. The oldest intrusive phase is a coarse-grained, equigranular monzodiorite intrusion that is restricted to the deeper parts of E26. This ...