Castle Resources finds more copper below mined-out ore bodies at Granduc

Toronto-based junior Castle Resources (CRI-V) wants to redevelop the past-producing Granduc copper mine near Stewart, British Columbia, which produced 420 million pounds of copper plus gold and silver credits between 1971 and 1984.

Results from Castle’s recently completed drill program have brought it one step closer to that goal, demonstrating significant copper mineralization beneath the mined-out ore bodies of the former producer, which was closed in 1984 due to low copper prices.

Intersections from its 8,300 metre, 18-hole drill program have shown a strong pattern of increasing copper grade and lens thickness in both downdip and to the southwest, the company reports.

Moreover, drilling to the southern end of the historic ore body has successfully linked up with positive drill results received in 2005 and 2006 by Granduc’s previous owners, Bell Copper (BCU-V), which extended the known strike length of the historic mine by more than 600 metres to the south.

Bell Copper’s exploration activities between 2004 and 2007 confirmed mineralization within 4 km to the north and south of the main Granduc orebody.  

Castle’s 2010 drill program was intended to test the down dip extent of the historical deposit and replicate some of the drill results produced by the mine’s former operators, Newmont Mining(NMC-T, NEM-N) and Esso Minerals.

All of Castle’s holes encountered visible copper along a 1,000-metre strike length. Highlights include 6 metres of 1.01% copper in hole GD10-11; 16 metres of 1.38% copper including 3 metres of 2.05% copper in hole GD10-15; 10 metres of 1.21% copper in hole GD10-14, and 12 metres of 1.32% copper in hole GD10-17.

Castle claims its initial results suggest that the historical insitu resource estimates by Newmont and Esso are reliable. In the next field season, the company will target the balance of the downdip mineralization and extend the strike to the south.

Newmont and Esso Minerals operated the Granduc mine for thirteen years, processing over 15 million tonnes of ore grading 1.71% copper. The operators invested more than $115 million from October 1965 until start-up operations began in 1971.

 Mining operations at the Granduc mine consisted of crushing underground then processing of up to 9,000 tonnes per day. The concentrate was trucked on a 54 km all-weather road to the year-round deep sea port facility in Stewart, which remains in operation today.

A 17 km haulage tunnel connecting the Granduc underground workings with the former mill site remains intact today and is in good condition.

Next on the agenda is to complete a resource estimate based on a combination of 2010 and historic drilling and commissioning a preliminary economic assessment.

Castle is also working on an exploration and mine rehabilitation plan that will concentrate on the balance of targets not yet drilled downdip and along strike.

This will involve the partial rehabilitation of the 17 km long tunnel connecting the Granduc underground workings with the former mill site and parts of the mine infrastructure, including ramps and exploration drifts that were originally developed by Newmont and Esso.

Castle’s shares closed up 3¢ or 6.12% at 52¢ apiece. Over the last year the junior has traded in a range of 7.5¢-57¢ per share.