Nova Scotia-based NovaGold Resources (NRI-T) reports that diamond drilling has begun at the Koala project in central Chihuahua state, Mexico.
In February, the company acquired a 20% interest in the 990-ha Koala group of claims from Consolidated Magna Ventures (CMV-V). NovaGold can earn an additional 25.9% stake in the claims and a 51% interest in 11,770 ha of surrounding claims by spending US$3 million on exploration.
The 2,000-metre drill program, budgeted at $500,000, will test coincident geological, geochemical and geophysical anomalies that could reflect buried replacement-type lead-zinc-copper-silver mineralization. These anomalies occur in a corridor of mapped alteration, brecciation and mineral showings.
Similar geological situations in northern Mexico led to the discovery of the Santa Eulalia and Naica mining districts, where total historical production plus current reserves exceed 85 million tonnes grading 10 to 15% combined lead-zinc-copper plus 150 to 350 grams silver per tonne.
According to NovaGold’s 1995 annual report, the Koala deposit has a copper reserve, minable by open-pit methods, of about 661,000 tonnes of primary and secondary mixed copper sulphides grading 2.5% copper.
The company reports that underground potential also exists. Previous surveys by Magna identified a large area of anomalous lead-zinc-copper mineralization in altered limestones with a coincident induced-polarization (IP) anomaly that suggested the presence of sulphide mineralization at depths of 200 to 300 metres. The current drill program follows an expanded geophysical program that included the extension of the IP anomaly to the southeast and a gravity survey over the entire IP anomaly.
A zone of high chargeability has been extended by 1,000 metres to the southeast and is now defined as being 3,500 metres long and up to 800 metres wide. A subtle, but persistent, gravity anomaly occurs near the centre of the IP anomaly.
Mapping and soil sampling have been extended to the southeast, and several new zones of alteration have been found to correlate well with the geophysical results.