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Contents : FEBRUARY 2007 PRIMEFACT 555 (REPLACES MINFACT 33) C obar's mining history Mineral Resources Of the major mining centres in the Cobar region Cobar Canbelego Nymagee Shuttleton and Mount Hope all have important deposits hosted in Early Devonian rocks belonging to the Cobar Supergroup. These include leading base metal mines (Elura CSA Great Cobar Chesney) as well as the State's largest (New Occidental) and second largest (Mt Boppy) gold producers. Other centres such as Girilambone have their deposits hosted in older basement rocks. With the exception of Elura all mining centres became sites for prospecting and mining following the initial collection of copper-stained samples at a native waterhole near Cobar by a party of travellers. Many deposits occur at topographic rises assisting early discovery. In a small minority of cases there are clear relationships with granitic intrusions principally for late found minor prospects to the north of Cobar. Copper was discovered at Cobar in 1869. Extraction commenced at the site of the Great Cobar mine and the first load of ore was despatched via Louth in 1871. Since then many other deposits and prospects have been found. Mining has produced major amounts of copper lead zinc silver and gold plus minor quantities of by-products such as cadmium and antimony. More recent developments include the opening of the new deep CSA mine in 1965 the discovery of Elura in 1973 and the commissioning of The Peak. Discoveries are ongoing (e.g. McKinnon's Tank Stones Tank). There are three important mining belts in the Cobar area the 'Cobar belt' 'Canbelego belt' and 'Girilambone belt'. The area's current two major mines Elura and CSA are both within the Cobar belt. The Cobar belt passing through Cobar town area is the most important of the three major belts. It is believed to contain the largest Phanerozoic concentration of base metals in New South Wales and one of the largest in Australia. Cobar is a major NSW metalliferous centre ranking second only to Broken Hill in renown and continuing importance. It is a constant major exploration target zone. Major deposits are found along the Cobar belt for some 60km from Elura Mine in the north to the Queen Bee Mine in the south. Historical and indicated ore reserves of this belt amount to more than 431 000t copper 1 600 300t lead 2 500 000t zinc 4 050t silver and 56t gold. Larger total metal figures result if non economic disseminated metal occurrences are estimated and included. According to its estimated total metal content the belt contains 5.3Mt base metals 5 000t silver and 90t gold. The estimated total content of 5.3Mt base metals might comprise 1.1Mt copper 1.6Mt lead and 2.6Mt zinc but this can only be a rough determination. The probable gold accompaniment to these metals would be 70t . The metals are hosted in an estimated 85Mt or more of mineralised rock. Motoring at the Cobar Chesney Gold and Copper Mine about 1910 The economic dependency and sensitivity of mining at Cobar is fundamental to any complete appreciation of the deposits. The Cobar mines have long required the strictest economy in management with the margin never very great between loss and profit since the general exhaustion of the secondary enrichment zone ores (in the 1880s in most mines later for CSA and Elura). The earliest prospecting activity in the area is poorly documented but was probably in the Cobar belt in the 1860s. Settlement was being extended along the Barwon River in the 1840s while by the 1850s the Darling River frontages were also occupied and there was speculation as to what the ranges back from the river might hold. The first mineral exploration in the region was to the north of Cobar and was by prospecting parties financed by Bourke businessmen prior to the discovery of copper and the establishment of Cobar town. Uneconomical gold traces were early discovered near Gongolgon and there is also noted to have been an early gold search in the Billagoe ranges probably in 1866. However the entire hinterland between the Barwon and the Darling saw little permanent settlement prior to 1870s so that prospectors were at that time unable to easily traverse it. They may not have ventured as far south as Cobar and the earliest results from the Billagoe ranges are uncertain. Commencing about 1869 a rapid spread of settlement began which was accompanied by well bore and tank sinking. From that point the record is clearer and it was in that phase of activity that the first signs of mineralisation were noted at Cobar and Girilambone. Persons engaged in the development of watering places travelled widely and were the first to happen on copper staining at both Cobar and Girilambone.Copper staining at Cobar (Great Cobar site) attracted the attention of two travellers in 1869. One of the same men Thomas Hartman from his experience at Cobar later recognised the outcrop of the Girilambone copper deposit in 1875

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