Atacama stacks oxide ounces at Cerro Maricunga

VANCOUVER — Toronto-based explorer Atacama Pacific Gold (ATM-V) has been on a big run over the past four weeks. Anticipation built as Atacama neared completion on a year-long resource drill program at its 100%-owned Cerro Maricunga gold property 140 km northeast of Copiapo, Chile. The pay-off arrived on Sept. 25 when the company unveiled a 65% increase in oxide-associated, measured-and-indicated resources at the project.

Atacama’s phase-three drill program — which was announced in July 2011 and concluded in June 2012 — covered 45,000 metres and carried a US$24.5 million price tag. The company focused on expanding existing resources along strike and to depth, and tested a series of new targets. Atacama’s second phase of drilling outlined oxide-hosted gold mineralization over three zones that covered 2.5 km of northwest-southeast trending that cross-cut the Cerro Maricunga volcanic complex.

The company was hoping to increase the size of its Crux gold zone, located on the deposit’s southern reaches. The drill program extended Crux’s total width to 450 metres, and increased the depth of mineralization to the northeast — an area Atacama had previously believed was unmineralized.

Additional drilling focused on delineation at the company’s Phoenix and Lynx zones in a bid to increase geological confidence in the deposit and extend mineralization along the majority of its strike length. Atacama reported that in-fill results at Phoenix-Lynx were “largely as anticipated, confirming the continuity of gold mineralization.”

On top of delineation activities at Crux, Lynx, and Phoenix, Atacama has been working on targets established at a newly discovered gold zone east of Phoenix it has labeled the Pollux zone. The company cut 11 holes and established a 400-metre strike length at Pollux during its 2012 program, and suspects the zone may represent a block of mineralization between Phoenix and Crux displaced to the northeast by faulting.

An additional gold zone was discovered 600 metres northeast of Phoenix, where hole CMR-190 returned 90 metres grading 0.49 gram gold per tonne.

Atacama’s resource program successfully boosted total resources at Cerro Maricunga to 164 million measured and indicated tonnes averaging 0.51 gram gold for 2.7 million contained oz. at a 0.3 gram gold cut-off grade. The project carries an additional 121 million inferred tonnes grading 0.47 gram gold for 1.8 million contained oz.

“The release of our [estimate] confirms that the Cerro Maricunga property hosts one of the largest oxide gold deposits in the world not owned by a gold producer”, president and CEO Carl Hansen stated. “The large oxide resource and remarkable continuity of the gold mineralization combined with excellent metallurgical recoveries suggest that Cerro Maricunga has the potential to be a very attractive development project.”

Hansen speculated on the potential for a heap-leach operation with a throughput rate of roughly 60,000 to 80,000 tonnes per day, and said the company expects a preliminary economic assessment will be ready for release by the fourth quarter. In January Atacama released results from eight column percolation leach tests that indicated gold recoveries from oxide materials ranging from 77% to 86%.

The Lynx and Phoenix zones account for roughly 73% of Atacama’s measured-and-indicated resources. Average grades fell from 0.54 gram gold to 0.51 gram gold due to lower-grade mineralization from Pollux and Crux. Pollux added 11 million measured and indicated tonnes grading 0.46 gram gold for 162,000 contained oz.

Atacama reported US$29 million in working capital at the end of June. The company has planned a fourth phase of drilling expected to commence in November and exceed 20,000 metres. The program will focus on upgrading inferred resources, in addition to testing exploration targets.

Atacama has surged 43% or $1.05 per share since mid-August en route to a $3.50 press-time close. The company has traded within a 52-week range of $2.21 and $5.51 per share on the back of average daily trade volumes of 135,000 shares.