Integra Gold expands drill program at Lamaque

Integra Gold (ICG-V) is delaying the release of an updated resource estimate that was scheduled for later this month, not because it has fallen on hard times like so many other juniors these days, but because new results from its 2013 drill program at the Triangle zone of its Lamaque project in Quebec are so significant that they need to be incorporated into the resource. Integra will also be expanding its 2013 drill program from 17,000 metres to over 20,000 metres.

Integra released the first results from drilling in the advanced-exploration Triangle zone in early April, with near-surface highlights of 5.2 grams per tonne gold over 13 metres, 14.17 grams over 2 metres and 12.20 grams over 4 metres. Further assays released in late April and the first week of June included 7.1 grams over 19.5 metres starting from 246.5 metres downhole, and 81.62 grams gold over 2 metres from 621 metres downhole.

The company says the latest results are significant for two reasons: First, the presence of high-grade mineralization to a vertical depth of more than 600 metres doubles the previously known depth extension of both the intrusive host rock and the gold-bearing veins at the Triangle zone. To put that in context, the past-producing Lamaque and Sigma mines, which have similar geology and lie a few hundred metres to the north of the Lamaque property, were mined from surface to depths of 1,000 and 2,000 metres. Secondly, the width of a number of these high-grade intersections, the longest being over 19 metres, have never before been seen in the Triangle zone.

The Lamaque property — previously a joint venture that was 50%-owned by Teck Resources (TCK-T, TCK-N) — does not include either mine, but shares its northeastern border with the Sigma mine. (Sigma is on care and maintenance and owned by Deutsche Bank, which is looking for a buyer.) Between 1923 and 1985, the Lamaque mine, operated by Teck, produced 4.6 million oz. gold from more than nine mineralized zones, while Sigma produced 4.5 million oz. between 1935 and 2012.

Integra, formerly known as Kalahari Resources, bought Teck’s portion of the property in 2003, and the remaining 50% from Golden Pond and Tundra in 2009. A year later Kalahari transitioned to a new management team and changed its name to Integra Gold. 

The Lamaque project is split into the South Cluster and the North Cluster, which are separated by less than 1 km. The South Cluster, which contains the Triangle zone and the No. 4 Plug, is located 4 km from the city of Val-d’Or and is the company’s top priority. The South Cluster accounts for 75% of Lamaque’s global resource.

Indicated resources in the South Cluster stand at 140,840 tonnes grading 13.51 grams gold per tonne for 61,168 contained oz. gold. Inferred resources add 1.3 million tonnes grading 11.06 grams gold for 444,962 contained oz. gold.

The North Cluster contains the No. 5 plug, which is about 1,000 metres north of the South Cluster’s No. 4 Plug. It also contains the Parallel and Forestel zones. The North Cluster has indicated resources of 659,959 tonnes grading 4.8 grams gold per tonne for 101,794 contained oz. gold, with inferred resources of 1.1 million tonnes grading 2.03 grams gold for 69,981 contained oz. gold.

Integra is confident that its upcoming resource estimate will warrant further advanced-stage studies and has already launched an environmental baseline study, metallurgical studies and a Gap analysis. The latter will focus on identifying potential applicable legal and permitting requirements, as well as linking those to required technical studies.   

In February it kicked off the first phase of metallurgical studies on mineralized samples from the South and North Clusters, and results released in May exceeded expectations. Test work reported initial gold recovery of up to 92% for samples from the South Cluster and of up to 98% from the North Cluster.

President and chief executive Stephen de Jong noted at the time that the high gold recoveries of more than 90% were “consistent with what was achieved for over 60 years on similar types of mineralization at the Lamaque and Sigma mines,” and also showed the lack of deleterious and hazardous elements in the tailings produced. Phase one involved optimized flow sheets involving gravity separation, followed by direct cyanidation.

The phase two studies that are underway will focus on optimizing gold recovery using grinding, cyanide concentration, leach time and adding flotation to the flow sheet. The second-phase studies should be completed by September.

De Jong says the project ticks a number of boxes. “If you look at our project, we’re high grade and near infrastructure, with all the benefits of being close to a mining community without interfering  — the town acquifer and well is on the other side of town, and there is little to no development where we are — and you have past-producing mines next door,” he says in a telephone interview from his office in Vancouver. “These mines have similar geology and produced through periods of high and low gold prices, and while it’s too early to talk about economics, historically they were low-cost producers, so US$1,400 per oz. gold is not the end of the world for us.”

He continues that “the old saying at Val-d’Or is you drill for structure and drift for grade, which speaks to the importance of exploring from underground as quick as you can . . . we’re not trying to find a mine with a 20- to 30-year mine life. It will always be difficult to do that from surface with these types of deposits. The objective is to reach that critical mass, which might be a five-, six- or seven-year mine life, and get it to the point where you can justify the project economics. And we think that can be a lot sooner because of the existing mill infrastructure and so forth, which will impact the capital expenditures that are needed. The Lamaque and Sigma mines are the perfect example, where you have over 60 years of proven production from deposits that seldom had more than five years’ mine life.”

In addition to exploration drilling at the Triangle zone, the company says it is encouraged by both the grade and frequency of veins at the North Cluster’s No. 5 Plug. Exploration at the No. 5 Plug was still in its infancy when Teck first joint-ventured the project in the late 1980s. Integra’s current exploration at the No. 5 Plug is the first significant, co-ordinated program there since 1988.

In January, highlights from drilling the No. 5 Plug included intercepts of 43.6 grams gold over 2.9 metres, 38.74 grams over 1.8 metres and 21.12 grams over 1 metre. The mineralization was identified from surface to a vertical depth of 650 metres, and the drilling demonstrated that the mineralization occurs through the intrusive plug, which remains open at depth.

Integra notes that the No. 5 Plug is unique in the sense that it has had little surface exploration in the past, but there are three underground drifts at varying levels down to a vertical depth of 1,000 metres, all of which encountered gold mineralization. Moreover, the underground workings connect the No. 5 Plug with the Sigma and Lamaque mines.

In terms of geological setting, Lamaque is in the Malartic Composite Block in the southeastern part of the Abitibi greenstone belt. About 50 km southeast is the Grenville front, and 1 km south of the southern edge of the Lamaque property is the Cadillac-Larder Lake fault zone. The Bourlamaque batholith lies 1.6 km northeast of the property.

Integra has $3.5 million in cash, including Quebec mining credits, which work out
to $1 million and are due any day now, de Jong notes.

Over the last year Integra has traded in a range of 12.5¢ to 39¢, and at press time was trading at 17¢ apiece.