Having demonstrated the commercial potential of the Renard group of kimberlitic bodies in north-central Quebec by recovering large diamonds at encouraging grades,
The joint venture consists of more than 3,800 sq. km of mineral permits, which are divided into four property blocks: Foxtrot, Tichegami, Taiga and Caniapiscau.
The Precambrian-age Superior Craton, underlying parts of Manitoba, Ontario and Quebec, is the world’s largest stable platform of ancient crustal rocks. The discovery of the promising Victor kimberlite pipe by
Publicly reported kimberlite occurrences on the Quebec portion of the Superior Craton include:
– fields of weakly diamondiferous kimberlites in the Desmaraisville and Temiscamingue areas;
– the Lac Beaver and more recent H1 and H2 kimberlite discoveries in the Tichegami River area of the Otish Mountains; and
– the kimberlite dykes and sills in the Wemindji area, on the eastern side of James Bay.
Ashton and Soquem discovered the first two Renard diamond-bearing kimberlitic bodies in September 2001 during a first pass of drilling designed to test four magnetic geophysical targets. Six more diamond-bearing kimberlitic bodies were drilled in 2002. The joint venture had quietly been conducting reconnaissance heavy-mineral sampling in northern Quebec since 1996. More than 1,700 samples were initially collected across an area measuring 425,000 sq. km, representing a density of about 1 sample per 250 sq. km. Most of the samples were taken from eskers. Several samples yielded anomalous grains of kimberlite indicator minerals, including a sample site in the Otish Mountains at the southern end of the regional-phase reconnaissance.
All anomalous kicks were followed up with a grid pattern of till sampling. One of the follow-up samples in the Otish Mountains yielded hundreds of indicator minerals. The heavy mineral concentrates returned several pyrope garnets with kelyphite rims and abrasion features suggesting they had not traveled far. A number of ilmenite grains with fresh abrasion features were also recovered. The chemical compositions of the ilmenite and pyrope garnets were suggestive of a diamond-bearing host rock.
Ashton and Soquem followed the indicator mineral train up-ice to a cutoff and began acquiring a land position in the Otish Mountains, 275 km northeast of Chibougamau, in the fall of 2000. A magnetic survey was flown at 200-metre-line spacings in late 2000 over a portion of the 1,530-sq.-km Foxtrot property. The survey was centred over the most positive indicator mineral samples. Drill targets were further defined by ground geophysical surveys and heavy mineral sampling in 2001, along with the discovery of a fist-size piece of kimberlitic float 400 metres down-ice from the Renard 1 target.
The eight known Renard kimberlitic bodies are tightly grouped inside an elongated, 1.5-km-long area. Within that cluster, Renard 2, 3, 4, 5, 6 and 8, along with one untested anomaly, occur in a core area that measures less than half a square kilometre. The Renard bodies consist of hypabyssal kimberlitic material and kimberlitic breccia. Flanking several of the bodies are broad zones of country rock breccia, consisting of fractured and brecciated country rock with variable amounts of kimberlitic material.
All eight of the kimberlitic bodies have been tested for microdiamonds and all have been found to be diamondiferous. Discovery hole samples ranging from 101 to 207 kg were subjected to caustic fusion analysis, and a significant number of microdiamonds were recovered. Moreover, some larger diamonds were recovered from these small drill core samples. A 0.13-carat diamond measuring 4 by 2.7 by 1.9 mm was recovered from Renard 3.
Results of the caustic fusion analysis are shown in Table 1.
During the spring and summer of 2002, mini-bulk samples of slightly less than 5 tonnes were recovered from each of the Renard 2, 3 and 4 bodies. The samples were processed through Ashton’s dense media separation (DMS) plant in North Vancouver and returned an estimated diamond content of 0.67 carat per tonne for Renard 2, 1.34 carats per tonne for Renard 3 and 0.65 carat per tonne for Renard 4. The DMS process recovered only diamonds larger than 0.85 mm using a square aperture screen.
In addition, DMS tests on core samples weighing less than 500 kg from the discovery holes on Renard 5 and 6 yielded a 0.92- and a 0.26-carat diamond, respectively. Ashton is encouraged by the consistent recovery of large stones from small-tonnage samples, which it says provides evidence of a coarse diamond population and a favourable grade distribution.
Large stones
“What’s most significant about the kimberlites in the Renard area is that they are consistently yielding large stones,” Ashton President Robert Boyd told delegates at the annual convention of the Prospectors & Developers Association of Canada. The encouraging results are outlined in Table 2.
Although the Renard bodies are limited in size, Ashton believes that, taken together, they have the potential to provide a viable resource. An aggressive delineation drilling and mini-bulk sampling program in the core area of the Foxtrot property has already begun. Forty tonnes of kimberlitic material are being recovered to ensure a cumulative mini-bulk sample of 10 tonnes from each of Renard 2, 3, 4, 5 and 6. Delineation drilling will provide the joint venture with a better estimate of the true size of the bodies.
The second objective of the 2003 program is to discover additional kimberlitic bodies within the Renard cluster and elsewhere on the Foxtrot property. Ashton and Soquem plan to drill the untested anomaly that sits 150 metres south of Renard 4, as well as generate more targets through ground geophysics. “We have many unexplained indicator mineral and geophysical anomalies away from the Renard cluster,” said Brooke Clements, Ashton’s vice-president of exploration, who addressed delegates at the recent Cordilleran Roundup convention in Vancouver, B.C.
In the summer, the partners intend to carry out heavy mineral sampling, geophysical surveys and drilling. In 2002, work on Ashton’s other properties in north-central Quebec focused on heavy mineral sampling and geophysical surveys. Several targets have been identified on the Tichegami property, but further work is required before drilling can proceed.
De Beers/Dios deal
Perhaps intrigued by Ashton’s success in the Otish Mountains, the Canadian exploration division of De Beers has struck a deal with
De Beers can earn an initial 51% interest in the 33 Carats project by spending $5.5 million on exploration before the end of 2008. By completing a feasibility study, De Beers can boost its interest to 60%. Once De Beers delivers a positive feasibility study, Dios will have the option of maintaining a 40% working interest or dropping to a 30% carried interest. De Beers has agreed to subscribe to a $250,000 private placement in Dios for 500,000 shares at 50 apiece, with a warrant exercisable at 65 for 12 months.
The 33 Carats project covers 920 sq. km. Dios, which was spun-off from
r’s core holdings in the Otish Mountains. The Eastern and Northern property blocks are within 20 km of the Renard discoveries, and all four blocks sit within 30 km of each other.
In the fall of 2001, Dios initiated a helicopter-borne reconnaissance program of basal till sampling over the four properties, collecting 185 samples. The till samples yielded various indicator minerals, including chrome diopsides, ilmenites and chromites. Crews recovered a single pyrope garnet from five undisclosed sample sites several kilometres apart. Some of the pyrope garnets were determined to be the highly prized G10s. At least one of the pyropes exhibited a sub-kelyphitic texture.
Larger position
Dios carried out further till sampling and prospecting last summer over the prospective target areas and, in the process, continued to enlarge its position in the Otish Mountains. The company purchased 110 sq. km of new claim blocks from
Dios continues to hold a 100% interest in the 539 sq. km Hotish claim group, 100 km south of the Renard cluster and just north of Lake Mistassini. High kimberlite indicator mineral grain counts include G10 chemistry, as well as the recovery of kimberlite fragments from last year’s till sampling.
Majescor and
Canabrava and Majescor will spend $400,000 to explore Mistassini further with till sampling and high-resolution airborne geophysics. Canabrava can earn a half-interest by spending $1.3 million on exploration.
In the meantime, Majescor is going it alone at the Portage project, which sits down-ice of the Renard cluster, after the Canadian diamond division of
Elsewhere in Quebec, Majescor is planning a limited program of reverse-circulation work in the Nottaway area, south of James Bay. Results from 250 alluvium and glacial sediment samples have enabled Majescor to outline a large indicator mineral anomaly. The company has assembled a land position based on agreements reached with BHP Billiton,
TABLE 1: CAUSTIC FUSION MICRODIAMOND RESULTS
KimberliticInferredSampleMicrodiamondLargest
| Body | Dimensions | Size | Count | Diamond | |
| (m) | (kg) | (mm) | |||
| Renard 1 | 100 by 150 | 206 | 89 | 0.9 by 0.5 by 0.3 | |
| Renard 2 | 120 by 650 | 163 | 145 | 1.6 by 1.6 by 0.5 | |
| Renard 3 | 120 by 200 | 207 | 81* | 4.0 by 2.7 by 1.9 | |
| Renard 4 | 140 by 600 | 153 | 54 | 2.5 by 2.1 by 0.9 | |
| Renard 5 | 80 by 80 | 144 | 53 | 2.5 by 2.0 by 1.8 | |
| Renard 6 | 120 by 120 | 152 | 37 | 1.2 by 1.0 by 0.8 | |
| Renard 7 | 150 by 600 | 101 | 33 | 0.4 by 0.4 by 0.2 | |
| Renard 8 | 75 by 40 | 112 | 9 | 0.6 by 0.6 by 0.5 |
*In addition, approximately 2,500 fragments were recovered from the breakage of one or more larger stones.
TABLE 2: DMS RESULTS
| Kimberlitic | Sample | Total Recovered | Largest Diamonds | Estimated | |
| Body | Weight | Diamonds | Recovered | Diamond Content | |
| (tonnes) | (carats) | (carats) | (carat/tonne) | ||
| Renard 2 | 4.94 | 3.31 | 0.38, 0.16, 0.16, 0.14, 0.14 | 0.67 | |
| Ren ard 3 | 4.88 | 6.54 | 0.73, 0.31, 0.25, 0.23, 0.22 | 1.34 | |
| Renard 4 | 4.81 | 3.11 | 0.28, 0.26, 0.16, 0.16 | 0.65 | |
| Renard 5 | 0.36 | 0.95 | 0.92 | * | |
| Renard 6 | 0.46 | 0.26 | 0.26 | * | |
*not applicable due to small sample size
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