Shoshonite-hosted Endeavour 48 porphyry copper-gold deposit, Northparkes, central New South Wales

The Endeavour 48 copper-gold orebody is the most recent discovery in the Northparkes Project, located in the Goonumbla district of central New South Wales. The discovery resulted from a small team conducting a systematic appraisal of high-quality geological and geophysical datasets collected over 20 years of exploration in the Goonumbla district. A key element of the discovery was a rigorous assessment of low-level aeromagnetic data coupled with persistence in drilling narrow, pipe-like targets. The Endeavour 48 deposit is a shoshonite-hosted porphyry copper-gold deposit. Mineralisation is associated with quartz stockworks and a late-stage magmatic derived sericitic overprint, and is closely related to at least two stages of quartz monzonite porphyry intrusion. These are genetically related to the biotite quartz monzonite stock (Endeavour 31) which forms the base of the deposit. The mineralisation is hosted by the intrusions, volcaniclastic sandstones, coarse volcaniclastic breccias and latitic (shoshonitic) lavas. The intrusive and volcanic suite are shoshonitic, based on their petrographic and geochemical characteristics. Pervasive biotite-magnetite +/- K-feldspar alteration forms the earliest alteration phase which is overprinted by sericite, carbonate, albite, hematite, biotite, magnetite +/- K-feldspar related to the main quartz-bornite stockwork veining. The final alteration assemblage is a strong pervasive sericite-carbonate-albite-clay mineral overprint, which is associated with high-grade disseminated copper and gold mineralisation. Endeavour 48 lies on Endeavour Linear and the mineralising porphyries, together with quartz veining, follow this trend. A low-angle fault (Altona Fault) truncates the top of the deposit 50 m below surface.