Arimetco gets copper values above Ann Mason deposit

Copper oxide specialist Arimetco International (TSE) recently obtained some encouraging results from drilling at a huge copper deposit located three miles from its Yerington mine in Nevada.

The reverse circulation drill program was designed to test extensions to the known limits of reserves previously defined by Anaconda Corp. on Arimetco’s Ann Mason deposit from 1968 to 1976. Arimetco says two of three drill holes intersected higher-grade copper porphyry mineralization nearer to surface than previously encountered by Anaconda.

Part of Arimetco’s ambitious growth plans, Ann Mason contains estimated reserves of half a billion tons grading 0.4% copper per ton including a high grade core of 110 million tons averaging 0.51%. But as most of the Ann Mason reserves are situated at least 500 ft. from surface, analysts are concerned about a high stripping ratio if the deposit is ever mined.

Arimetco has doubled the capacity of a 25,000-lb.-per-day solvent extraction, electrowinning (SX-EW) plant at its Yerington mine in the hopes that Ann Mason will eventually be developed.

However, Arimetco says the latest results, combined with work completed by Anaconda, may allow it to reclassify a significant volume of the rock as ore. Assays from the summer program include 120 ft. of grade 0.38% copper from 150-270 ft. and 80 ft. of grade 0.42% copper from 165-245 ft. Early next year, Arimetco will attempt to identify more near-surface ore by spending $200,000 on further drilling, surveying and engineering studies. Because assays from drilling this year indicated that as copper values increase so too do gold values, the company plans to re-assay selected intervals from Anaconda drill core.