Norseman Gold operates Australia's longest continuously running gold mining operation, having produced over 5.5 million ounces of gold over a period of more than 65 years from its Norseman field located 725km east of Perth, Western Australia.
The Main Fields region encompasses the Bullen, St Patricks, Norseman, Mararoa, O’Brien and Crown (Regent) deposits. St Patricks and Norseman are the most significant contributors of these deposits to the reserve base.
Gold mineralisation in the Main Fields region is typically hosted within narrow vein quartz reefs. The Mararoa and Crown Reefs, that have historically hosted the bulk of the mineralisation, strike north-south and northeast-southwest respectively. The Norseman Reef is also hosted by a major north south striking structure, however, is less mineralised than Mararoa and Crown Reefs. All three reefs dip towards the east.
East west striking structures or ‘cross link’ structures have also been found to host quartz reefs and gold mineralisation. The Bullen Reef (including Bullen West) is hosted in a cross link structure between the Crown and Mararoa Reefs and dips towards the south. The St Patricks Reef is hosted in a cross link structure between the Mararoa and Norseman Reefs and dips towards the south. The O’Brien Reef is hosted in a north south striking and east dipping structure between the Crown and Mararoa Reefs.