Expanding Caribou Dome
Perth-based explorer sees world-class potential of Alaska copper project
Last updated 6/12/2016 at Noon
Australia-based Coventry Resources Inc. has kicked off an extensive exploration program aimed at expanding zones of high-grade copper at Caribou Dome, a road-accessible property located about 155 miles north of Anchorage.
"We anticipate spending around AU$2 million on the current work program that will comprise circa 8,000 meters of drilling, an extensive (induced polarization) survey, and further soil sampling/mapping in prioritized areas where previously very little, if any, exploration has been undertaken. On completion of that work, we will determine appropriate follow-up work programs and budgets," Coventry President and CEO Mike Haynes told Mining News.
Though based in Perth and listed on the Australia Stock Exchange, Coventry is not a stranger to Alaska. The Down Under company has been exploring the Far North State since at least 2011, when it (then known as Crescent Resources) optioned the Uncle Sam gold project near the Pogo Mine.
"Coventry believes there is exceptional potential to discover new economic mineral deposits in Alaska, and indeed that it is likely there are still multiple world-class mineral deposits to be discovered there," Haynes explained. "We are also attracted by what we believe to be very encouraging geopolitical conditions that are supportive of exploration for, and development of, mineral resources. Importantly, Alaska is a safe jurisdiction to operate in, both from a personal and security of tenure perspective."
The company believes Caribou Dome is a prime example of Alaska's potential. Exploration in the 1960s discovered 10- to 20-meter thick lenses of more than 5 percent copper at this project situated on the southern slopes of the Alaska Range.
With only sporadic exploration carried out on the property since about 1970, Coventry has a hunch that a broader investigation could uncover a much larger copper deposit that is lying in wait.
"(W)e believed that the project was very much under-explored, and that in light of the geological style of the mineralization, there was considerable potential to delineate additional mineralization of similar high-grade by undertaking further exploration," Haynes explained.
Upon cutting the deal to acquire an 80 percent stake in Caribou Dome in February of last year, Coventry began pouring over exploration data collected at the project, including results from 95 surface and underground drill holes that tested some of the nine lenses of high-grade copper for which the project is known.
Highlights from this historical work include:
18.1 meters averaging 9.34 percent copper from a depth of 22.7 meters;
18.4 meters averaging 6.25 percent copper from a depth of 31.4 meters;
15.4 meters averaging 7.01 percent copper from underground; and
11 meters averaging 8.2 percent copper from a depth of 29 meters.
Most of the historical drilling tested lenses four, five and six - with the idea that they would support a small high-grade underground mine.
Based on this drilling, a historical reserve of 550,000 short tons averaging 5.84 percent copper was calculated for the Caribou Dome deposit in 1970.
While this outcropping deposit is a great place to start, Coventry sees the potential that Caribou Dome hosts a deposit that would support a much bigger high-grade copper mine.
"(W)e believe there is potential to discover additional mineralization from one end of the project to the other, over 18 kilometers (11 miles) of strike, as well as at depth," Haynes wrote in an email response to questions from Mining News.
Coventry began exploring this potential last year with a program that included 4,300 meters of drilling; ground IP surveys centered on the known mineralization; and an extensive soil sampling program.
Highlights from the 22 holes drilled at and around the Caribou Copper deposit in 2015 include:
14.1 meters averaging 9.9 percent copper from 134.6 meters;
Seven meters averaging 6.8 percent copper from 35.1 meters; and
3.5 meters averaging 9.3 percent copper from 72.9 meters.
The soil sample program carried out last year unveiled an extensive copper-in-soil anomaly over the entire 7,000 meters of strike tested, including a highly prospective 2,000-meter area that blankets the outcropping lenses, of which only about 700 meters have been tested by drilling.
One rock chip sample collected at the Menel Target - which is about 250 meters northwest of the nearest drill hole - returned 9.1 percent copper.
Strong, yet-to-be-drilled, induced polarization anomalies also have been identified at Menel, making it a priority target for this year's drill program.
Beyond Caribou Dome
In addition to Menel, this year's 8,000-meter drill program will test three other undrilled IP targets - Guardian, Lense 9 and Lense 3 - all three of which are located northwest of the Caribou Dome deposit.
A 150-meter-long IP anomaly at Lense 3 is the first target on the docket for the program now underway.
Three holes drilled in 2015 hit copper mineralization above the 150 foot deep Lense 3 IP anomaly being targeted this year:
2 meters averaging 13.9 percent copper from 79.4 meters;
1.9 meters averaging 7.7 percent copper from 32.6 meters; and
4.9 meters averaging 3.4 percent copper from 32 meters.
An IP anomaly similar in size and depth as the Lense 3 target has been identified at Lense 9.
Guardian, located about 200 meters north of Lense 9 and about the same distance west of Menel, hosts another 250-meter-long strong IP anomaly that coincides with recently discovered gossans. One sample collected from these weathered and oxidized outcrops returned 16.5 percent copper.
Given the targets turned up by the 1,500 meters covered by IP surveys carried out in 2015, Coventry has decided to cover the balance of the 7,000 meters of copper-in-soil anomalies with similar geophysical surveys this year.
The company is optimistic about what its 2016 program and future work at Caribou Dome will uncover.
"We are undertaking this work in the knowledge that analogous sediment-hosted copper deposits, around the world, can be both very large (from a tonnage perspective) as well as very-high grade," Haynes explained. "It is possible, but of course somewhat less likely, that one of the largest and/or highest grade copper deposits is present within our project. Until we undertake systematic exploration we won't know."