A record crowd of 136 showed up at the SME Tucson chapter dinner meeting last night to hear Oracle Mining Co. VP and geologist Kevin Francis describe the geology, reserves, and progress in reopening the Oracle Ridge copper mine on the north side of the Catalina Mountains north of Tucson. [Right, map of workings and skarn zones. Credit, Oracle Mining Co.]
The mine's history extends back to 1873 and last commercial production was in 1996. The Canadian-based company expects its NI43-101 report to be completed in December, but historical resource estimates show 379 million pounds of copper (8.14 million tons of ore at 2.33% Cu). Kevin said they drilled 443 core holes totaling 161,000 feet, but 60% of the property is still unexplored.
They expect to produce about 2,000 tons of copper per year for a mine life of 10-12 years. All of the production has been pre-sold to an investment company that will take shipment of the concentrate locally.
Most of the copper is in a skarn in Escabrosa limestone overlying the Leatherwood granodidorite stock, which is the source of the alteration and mineralization.
The existing workings total 11 miles which all underlie private lands which has allowed permitting to move quickly.
Kevin commented on the support from the community of nearby Oracle to re-open the mine, noting that he has met so many people that have some tie to the mine. He asked for a show of hands of who in the audience had a connection and I estimate more than 20 hands were raised.
No lava flow visible in Holuhraun main crater
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