Calibre and B2Gold hit long gold intercepts in Nicaragua

Calibre Mining‘s (CXB-V) share price jumped to 50¢ from 19¢ with 42.5 million shares traded over two days after it announced three long gold-copper intercepts from its Primavera prospect in northeastern Nicaragua. B2 Gold (BTO-T) which is earning 51% of the project, saw its share price climb 41¢ to $3.49 on the news, with 9.6 million shares traded.

Results include hole 2 that cut 261.7 metres grading 0.78 gram gold per tonne and 0.3% copper, hole 1 that hit 276.8 metres averaging 0.5 gram gold and 0.22% copper and hole 3 that returned 123.9 metres carrying 0.65 gram gold and 0.28% copper, with all intercepts starting essentially at surface.

Holes 1 and 2 were collared from the same platform but hole 2 was oriented 75 degrees away, while hole 3 was collared more than 200 metres to the southeast. Holes 2 and 3 ended in mineralization.

The company states that all three drill holes intersected continuously mineralized intervals of stockwork and vein mineralization characteristic of other gold-copper porphyry systems, while mineralization is associated with quartz, magnetite, chalcopyrite and bornite-bearing stockwork and veining within potassically altered intermediate volcanic and intrusive rocks.

“It’s very much like a porphyry style,” says Douglas Forster, executive chairman of Calibre, by phone. “The host is intrusive and volcanic.”

The drill results are the first from the Primavera project, which sits within Calibre’s 860-sq.-km Borosi group of concession in the country’s northeast, 8 km south of the town of Rosita.

Forster explains that Calibre started exploring in the area at a vein outcropping much farther south. The company started trenching and grid sampling the vein area and eventually continued that exploration farther north under the 5 to 10 metres of saprolite that prevents any outcropping to the north. Last year’s trenching revealed long intervals of copper and gold in the region, including 179.4 metres grading 0.63 gram gold and 0.1% copper and 107 metres of 0.78 gram gold and 0.1% copper.

Meanwhile airborne geophysics outlined a 5-km by 5-km intrusive-volcanic complex, and ground geophysics work identified a gold-copper soil geochemical anomaly spanning at least 800 metres by 300 metres at Primavera, all leading to the recent drill program.

The first-phase diamond drill program consisted of 668 metres, while plans are in place to drill at least 2,000 metres more over the next few months with one rig on site to define the extend of the porphyry system. B2Gold has four other rigs in the region and might send one or more to the project to accelerate and expand the program.

The companies will be following up on several untested gold-copper anomalies identified on the Primavera concession, while Calibre will also be exploring for porphyries on its other properties in the region.

“Now that we understand the signature much better about what a porphyry like Primavera looks like geophysically, geochemically and geologically, we’re applying that new knowledge both to the joint venture ground and our wholly-owned properties in the mining triangle looking for more of them,” Forster says.

B2Gold, which took over as operator following the latest results, is earning 51% of several properties at the Borosi project by spending $8 million on exploration by 2014. So far the company has spent about half that amount. Once it has earned its initial 51% in the group of properties it can choose to advance one of the properties to the pre-feasibility stage to earn 14% more in that prospect.

The Primavera project is road accessible, and the national power grid lies just over a kilometre from the project.

Calibre has roughly $2 million in working capital and 167 million shares outstanding. The company fully owns the Riscos de Oro prospect at the Borosi concessions, where it has identified a gold-silver system extending for over 7 km in a low-sulphidation epithermal gold-silver vein district, while Alder Resources (ALR-V) is earning into the company’s Rosita copper prospect at Borosi.  

B2Gold controls the La Libertad and Limon gold mines in Nicaragua where in 2011 it produced roughly 135,000 oz. gold. In Nicaragua the company also has an option agreement with Radius Gold (RDU-V), and holds interests in properties in Colombia and Uruguay.