VANCOUVER — It remains early days for Cordoba Minerals (TSXV: CDB; US-OTC: CDBMF) at the San Matias copper-gold property, 200 km north of Medellin, Colombia, but there’s already excitement building around the property’s discovery prospects.
Cordoba has shown enough grade potential across the 260 sq. km land package to form a joint venture with mine-finder Robert Friedland’s private exploration vehicle, High Power Exploration (HPX), and on Jan. 5 it released a maiden resource estimate on San Matias’ Alacran deposit.
The estimate incorporates drilling through October 2016, totalling 76 diamond drill holes over 20,200 metres and including 11,230 metres drilled by Ashmont Resources in 2011 and 2012.
Alacran’s copper-gold mineralization consists of chalcopyrite-pyrrhotite-pyrite veins, replacements (including massive sulphides) and disseminations that locally overprint hydrothermal magnetite-rich zones developed near intrusion contacts.
The pit-constrained, inferred resource now stands at 53.5 million tonnes grading 0.7% copper and 0.37 gram gold per tonne, or 0.95% copper equivalent, including 7.4 million tonnes at 2.1% copper and 0.41 gram gold gold above a 1% copper cut-off grade. The conceptual pit runs over 1.3 km of strike and to 220 metres deep, while Cordoba describes the mineralization’s “broad horizontal widths” as “favourable for potential open-pit development.
“We have an economic deposit emerging at Alacran, and this resource demonstrates that we’re off to a great start, with strong grades. The copper grade we’re looking at here is twice what you’d see at most active mines,” Cordoba Minerals president and CEO Mario Stifano says during an interview.
“Obviously the next step is to demonstrate that size potential, but the benefit of having a resource is that it really increases your prospective investor base. The issue is that without a resource it’s extremely difficult to get institutional investors to look at your company,” he adds.
Cordoba drilled 13,000 metres at San Matias last year, and HPX’s budget over the first four months of 2017 is an estimated US$6 million.
HPX completed the second phase of its option agreement in late 2016, which involved spending $19 million on exploration to earn a 51% stake in the project. The third phase of the partnership would see HPX increase its stake to 65% by completing a feasibility study.
“Now it’s not only important for us to communicate where we see the resource growing through future drilling, but also the fact that we see ourselves in an emerging district,” Stifano says.
“There is definite potential here for multiple deposits, and multiple different styles of mineralization. We’re obviously looking at skarn-replacement systems like Alacran, but there are also promising targets in terms of porphyry systems,” he says.
Cordoba says the Alacran mineralized system remains open to depth, and surface geochemical anomalies indicated “significant potential for additional mineralized zones to the east and west.”
Drilling has intercepted copper-gold mineralization below the conceptual pit shell, and elsewhere at depths greater than 220 metres below surface, though drill density is too sparse to include the material in resource estimates.
The company will release results from the 2016 drill program during the first quarter. On Jan. 11, Cordoba reported that hole 33 returned “one of the best intersections to date on the project” east of the current resource shell, where it cut 108 metres from surface grading 1.3% copper and 0.87 gram gold.
Alacran’s mineralization has now been intersected over a 1.3 km strike length to widths of up to 400 metres, and to 260 metres below surface.
After the exploration campaign, Cordoba concluded that host stratigraphy appears to steepen from north to south, while the mineralization changes from pyrrhotite-pyrite-chalcopyrite to magnetite-chalcopyrite. Based on magnetic and induced polarization surveys, the company says “attractive exploration targets” remain down-plunge and along strike.
“We have some drill targets along the northern and southern end of Alacran I’d classify as exploration areas,” Stifano says.
“There is a massive magnetic anomaly down south that we believe offers a good chance to discover more mineralization. We’re dealing with a replacement system here, potentially a skarn, and it’s quite complex, but at the end of the day we have to find the fluids that actually fed the deposit,” he says.
The long game for Cordoba, however, would ideally involve finding a copper-porphyry deposit. The company is exploring along a 13 km potential porphyry trend, including diamond drilling at the Montiel East and Costa Azul targets. Additional skarn replacement-style mineralization and alteration has been found at the Buenos Aires target farther south.
“We have to focus on advancing Alacran and pursuing more blue-sky exploration,” Stifano says. “Alacran provides a great base of value for the company, but Robert Friedland and HPX have come into this deal with the intention of making a much more significant discovery. We think we could be looking at a land package with potential for a world-class deposit, and we’ve seen a lot of similarities to Oyu Tolgoi.”
Exploration work at Montiel East has focused on copper-gold mineralization associated with a series of porphyry dike and sill-like intrusives, and incorporates both sheeted and stockwork quartz-magnetite-chalcopyrite-bornite veins within strongly potassic-altered diorite porphyry.
Meanwhile, Costa Azul’s mineralization is reportedly associated with quartz-magnetite-chalcopyrite-pyrite-bornite sheeted and stockwork veining, both within diorite porphyry and mafic volcanic wallrocks.
Stifano points out that having its partner HPX fully fund exploration at San Matias means Cordoba “only needs to raise money to stay public.”
Cordoba’s shares gained over 400%, or 68¢, in 2016, and traded at 83¢ at press time. Cordoba has 87 million shares outstanding for a $78-million market capitalization, and had cash and equivalents of $2.5 million at the end of September 2016. Friedland also controls a 37% equity stake in Cordoba.
“In the junior mining industry we tend to feed institutional demand by doing a series of private placements, but from our perspective we’ve eliminated that, because we don’t need that cash,” Stifano adds.
“We don’t pay attention to short-term blips in stock prices. We’re trying to build a real mine here, so we aren’t necessarily focused on daily equity performance, because building a district-scale project involves a longer timeline than quarter-over-quarter trading, though obviously it’s nice to see the share price on the rise.”