Volta adds copper porphry to the Burkina Faso mix

Toronto-based explorer Volta Resources (VTR-T) has been adding quite a bit of copper to its already strong gold assets in Burkina Faso.

Though Volta’s flagship asset remains the development-stage Kiaka gold project, 140 km southeast of Ouagadougou, the company continues to advance its wholly owned Gaoua copper-gold porphyry project, with a major resource expansion announced on Jan. 23.

Gaoua is a 558-sq.-km land package on the Boromo greenstone belt, which includes the contiguous Malba, Souhouera and Danyoro permits that cover 35 km of strike length along an established copper-gold structural corridor.

The mineralization at all three of Volta’s drill prospects is associated with a hydrothermal breccia that is predominantly hosted by diorite-porphyry intrusions.

Following 47,800 metres of drilling completed since 2009, Volta boosted its global inferred resource at the project by 182% to 282 million tonnes grading 0.32% copper and 0.35 gram gold per tonne for 2 billion contained lb. copper and 3.17 million contained oz. gold. The resource carries a 0.53% copper-equivalent grade and is calculated using a 0.3% copper equivalent cut-off.

The resource combines Volta’s Gongondy and Dienemera targets. Gongondy contributes Gaoua’s only indicated resources, which total 22 million tonnes grading 0.29% copper and 0.33 gram gold for 138.6 million contained lb. copper and 236,300 contained oz. gold.

The project’s resources are all contained in two envisioned open pits that lie 6 km apart along Volta’s established porphyry corridor.

“This clearly demonstrates the potential to substantially further increase the size of the resources within the project,” president and CEO Kevin Bullock said, noting that Gongondy and Dienemera remain open along strike and downdip. “Initial drilling on another two targets — Mont Biri and Bouserra — has intersected similar copper-gold porphyry mineralization, while many more co-incident geophysical and geochemical anomalies represent first class porphyry targets that remain to be drill tested.”

Bullock explained in mid-December that extension drilling had given Volta an opportunity to expand Gaoua’s resource base, which would allow the company to realize maximum value for the project in order to focus on development at Kiaka.

With a number of other potential porphyry targets along Volta’s trend, it is possible the company is sitting on one of the sole bulk-tonnage, copper-gold targets in West Africa.

Meanwhile Volta released an additional resource update at Kiaka aimed at reassessing its development options and identifying continuity in higher grade lenses within Kiaka’s Main zone.

The company hopes to increase returns on the project by tapping higher-grade ore during early stage mining.

In early January, Volta revealed that Kiaka’s main lenses host 42 million indicated tonnes grading 1.52 grams gold for 2.04 million contained oz., as well as inferred resources of 5.5 million tonnes at 1.7 grams gold for 301,000 contained oz. gold.

“The primary objective of the work leading to this latest [resource update] has been met,” Bullock said. The company believes it can selectively mine and process sufficient tonnages at an average grade roughly 40% higher than the in-situ grade of the deposit for up to five years. “We can now confidently define discrete and continuous higher-grade [lenses] within the broader lower grade [Kiaka Main zone] envelope in the Central area.”

The revised plan involves a staged build-out where Volta could run a 6-million-tonne-per-year operation over the first five years of Kiaka’s life. An existing prefeasibility study modelled a US$610- million operation that would start out at the 12-million-tonne-per-year throughput level, but with the higher-grade core resource Volta could now begin operations at half that capacity and ramp-up its operations partly paid by cash flow.

The company intends to incorporate the staged concept into a feasibility study that is currently underway. Global measured and indicated resources at Kiaka jumped 10% in the update and now sit at 153 million tonnes grading 0.99 gram gold for 4.9 million contained oz. gold.

Volta’s original operation would have produced an average of 340,000 oz. gold annually over a 10-year life at cash costs of US$671 per oz. gold.

Volta has traded within a 52-week range of 40¢ and $1.71, and shares have remained relatively flat to start 2013. They traded as high as 52¢ in January, and closed at 47.5¢ at press time. The company saw high volumes following the Gaoua resource update with 1 million shares changing hands on Jan. 23. Volta maintains 155 million shares outstanding for a $73 million press-time market capitalization. The company reported it held $20 million in cash in mid-December.