Stornoway reports strong microdiamond count

Summer drilling on the AV-1 kimberlite showing on the Melville Peninsula in eastern Nunavut has returned highly significant microdiamond counts showing good potential for larger, commercial-size stones.

Discovered at the end of the 2002 field program, the AV-1 showing was tested this summer by Stornoway Diamond (SWY-V) with seven angle holes drilled from four setups. The exposed portion of the AV-1 discovery outcrops over a 76-by-13-metre area at the edge of a small shallow lake. Based on the drilling, the kimberlite body is believed to be at least 160 metres long and 40-60 metres wide. Hypabyssal kimberlite was intercepted in all seven holes, and a second, non-magnetic, brecciated macrocrystic kimberlite phase was encountered in six of the holes.

Caustic fusion analysis recovered 737 microdiamonds from 531.7 kg of core samples. A detailed look at the diamond-size distribution, using square mesh sieve sizes, is provided in the accompanying table. The three largest stones measured 4 by 3.5 by 1.8 mm, 2.34 by 2 by 1.76 mm, and 2.4 by 1.48 by 1 mm; all were recovered from the breccia phase of the AV-1 kimberlite. Both the hypabyssal and breccia kimberlite phases of the body returned comparable counts: 1.44 diamonds per kg and 1.32 diamonds per kg, respectively. However, based on the initial sieve results, the breccia appears to have a coarser diamond distribution.

This year’s drilling results compare favourably with the surface sampling that was done on the outcrop exposure of AV-1 in August 2002 and March 2003. In total, 1,613 diamonds were recovered from caustic fusion analysis of 1,136 kg of kimberlite surface material, for a microdiamond count of 1.42 stones per kg. This fall, a representative mini-bulk sample of approximately 8 tonnes was collected from the surface exposure of AV-1. The sample will be analyzed for larger-size macrodiamonds.

The Aviat project spans 5.5 million acres in the Melville Peninsula. Stornoway holds a 70% interest in the joint venture, while BHP Billiton (BHP-N) owns 20% and the Hunter Group has a 10% carried interest. In 2003, the joint venture spent $5 million exploring Aviat in a program that included the collection of 2,300 till samples, 56,900 line km of airborne geophysical surveys, prospecting, follow-up ground geophysical surveying, and 1,102 metres of core drilling.

New kimberlite float was discovered up-ice of AV-1, and a new, outcropping, diamondiferous dyke-like kimberlite body called AV-2 was found 4 km away from AV-1. The AV-2 exposure was tested by an inclined hole that intersected 2.6 metres of kimberlite followed by two other separate kimberlite sections of 9.3 metres and 3.1 metres. A second hole tested a magnetic anomaly 75 metres southwest of the AV-2 showing and encountered 2.2- and 6.5-metre-long sections of kimberlite.

An aggregate 39.4-kg sample of AV-2, including both breccia and hypabyssal phase kimberlite, delivered 30 microdiamonds. The largest stone was a lone diamond caught on +0.6 mm square mesh screen.

Previous regional till sampling had outlined a wide area of scattered kimberlite indicator mineral responses, suggesting multiple sources in the project area. The till-sampling density was increased throughout the project area, and detailed sampling was carried out in anomalous areas, including a prominent east-west-oriented corridor of elevated indicator mineral counts that contained AV-1.

“Preliminary data from 2003 suggest the potential for the discovery of additional diamond sources elsewhere in the landholdings,” says Stornoway President Eira Thomas. “Diamond exploration is still at an early stage, and regional work will continue to be a top priority for the joint venture in 2004.”

A larger drilling campaign is planned early in 2004, following the interpretation of results from this past year’s program.

Outside of the Aviat joint venture, Stornoway and the Hunter Group have farmed-out some of their non-core holdings on Melville Peninsula and Baffin Island. Navigator Exploration (NVR-V) and NDT Ventures (NDE-V) can earn a 60% collective interest in the Fury, Sarcpa and Gem properties by spending $1 million on exploration and maintaining the properties in good standing. Covering 1 million acres, the properties are being explored this year under a $600,000 budget.

In addition, Strongbow Resources (SR-V) can earn a 60% interest in the 2,000-sq.-km Melville property by spending $500,000 on exploration. This year’s budget was set at $200,000. Exploration in 2003 consisted of airborne magnetic surveying, till sampling and prospecting on each package of properties. Results are pending. BHP Billiton holds a 10% carried interest for the first $10 million in expenditures on each option agreement.