SHOSHONITE-HOSTED ENDEAVOR-48 PORPHYRY COPPER-GOLD DEPOSIT, NORTHPARKES, CENTRAL NEW-SOUTH-WALES

The Endeavour 48 copper-gold orebody is the most recent discovery in t he Northparkes Project, located in the Goonumbla district of central N ew South Wales. The discovery resulted from a small team conducting a systematic appraisal of high-quality geological and geophysical datase ts collected over 20 years of exploration in the Goonumbla district. A key element of the discovery was a rigorous assessment of low-level a eromagnetic data coupled with persistence in drilling narrow, pipe-lik e targets. The Endeavour 48 deposit is a shoshonite-hosted porphyry co pper-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 volcan iclastic breccias and latitic (shoshonitic) lavas. The intrusive and v olcanic suite are shoshonitic, based on their petrographic and geochem ical characteristics. Pervasive biotite-magnetite +/- K-feldspar alter ation forms the earliest alteration phase which is overprinted by seri cite, carbonate, albite, hematite, biotite, magnetite +/- K-feldspar r elated to the main quartz-bornite stockwork veining. The final alterat ion assemblage is a strong pervasive sericite-carbonate-albite-clay mi neral overprint, which is associated with high-grade disseminated copp er 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 depo sit 50 m below surface.