Page Index

The Anomaly
The Darnley Bay Magnetic and Gravity Anomaly
Diamonds

THE ANOMALY

Darnley Bay Resources Limited’s (DBR) main focus is exploration for base metals and diamonds in an area surrounding the hamlet of Paulatuk, located along the shores of Darnley Bay, in the Inuvialuit Settlement Region (ISR), NWT, Canada.

The area is the site of the strongest isolated gravity anomaly in North America which, together with a coincident magnetic anomaly, is termed by DBR as the "Anomaly."

THE DARNLEY BAY MAGNETIC AND GRAVITY ANOMALY

Base Metals: The Geological Survey of Canada (GSC), in 1994, assigned a moderate to a high rating for the Anomaly to be a major mineral complex comparable to the Sudbury Basin in Ontario, Norilsk in Russia, and to the Bushveld Complex in South Africa. These are mining districts known primarily for their great Nickel, (Ni) and Copper (Cu) production and are also prime platinum/palladium (PGE) producers.
Ref.: GSC. Open File 2789

At 130 milligals, the gravity anomaly is:

• four times stronger than the Sudbury Basin gravity anomaly, host of the world's largest Ni and Cu deposits.
• five times stronger than the Norilsk deposits where the mined grade of Ni and Cu is the highest in the world.
• twice as strong as the Bushveld Complex, estimated to contain 70% of the world's platinum group elements (PGE).

The estimated resources (including that already mined) of the compared world class deposits of Ni-Cu and PGE sulfide ores are as follows; Sudbury Basin in Ontario, 1648.0 million tonnes @ 1.20% Ni, 1.08% Cu, 1.17 g/t PGE, Norilsk region in Russia, 1309.3 million tonnes @ 1.77% Ni, 3.57% Cu, 9.50 g/t PGE, Bushveld Complex in South Africa, 11,549.9 million tonnes @ 0.13% Ni, 0.06% Cu, 5.67 g/t PGE.
Ref: Anthony J. Naldrett, Magmatic Sulphide Deposits 2004.

Review: DBR has undertaken a review of all available geophysical and geological data of the Anomaly and surrounding area. The available geophysical data indicate a large intrusive complex with interpreted similarities to the Sudbury Basin, the Norilsk deposits, the Bushveld Complex. The discovery of diamonds on surface within the Anomaly, and diamondiferous kimberlites on the nearby Parry Peninsula to the northwest, indicate the potential for a new diamond district in the NWT.

In the past, placer miners recovered gold and sulphides in the area of the Anomlay from local river bed alluvials. These minerals could have been derived from an overburden covered mineralized intrusive.

In 1997 DBR completed a high-resolution aeromagnetic survey within and around the area of the Anomaly. The survey covered 1,500,00 acres (607,050 ha) and was flown at an elevation of 120 metres in an east-west direction with a line spacing generally 800 metres apart, tightened to 400 metres over the core of the Anomaly, and loosened up to 1,600 metres apart northwest of the Anomaly.

The survey over the Anomaly indicated that, the main source is a buried intrusive body lying 1,000-3,000 metres below surface, and that it is complex and may be a multiple injection intrusion with parts re-mobilized after the original event. The magnetic data suggest that there are several high angle fault zones and dyke systems that show both vertical and horizontal displacements. The data indicated that the project area has been well prepared structurally to host mineral deposits.

Bouguer gravity image with outline of Darnley Bay magnetic anomaly and interpreted dykes and faults (PGW, 2001)

Gas resources in the general area of the Anomaly are hosted by the same source rocks that host significant reservoirs elsewhere.

DIAMONDS

The 1997 aeromagnetic survey located four clusters of magnetic anomalies in the area, which prompted DBR to also embark on a diamond project.

In 2000, DBR collected till samples within the area of the two most northerly clusters. The samples were found to contain many kimberlite indicator minerals, three of which carried diamonds. This is significant as only 1 in 30,000 till samples actually carry diamonds.

Surface Diamond Occurrences

Regional sampling results of stream sediments suggest that the main in-situ source(s) of recovered indicator minerals and diamonds within the Anomaly may be structurally associated with a southeast trending mafic dyke swarm.

DBR in a follow-up aeromagnetic survey at 200 metre line intervals on parts of the northerly clusters identified 39 kimberlite targets, which together with 55 from the 1997 survey totaled 94. Ground geophysical surveys were completed on 41 with 28 selected as priority drill targets. Only one of the targets is located under a lake.

DBR also collected some 22,000 lbs. (10 tonnes) of till and drill core samples for chemical analysis and 44 stream sediment and beach heavy mineral samples were collected and processed for indicator minerals. DBR drilled 12 kimberlite targets; 10 intersected kimberlite and 6 contained diamonds.

A joint venture with an optionee, whom has the right to earn 50% interest in the diamond project, has completed 52,000 line-kms of an airborne survey and has added an additional 11 highly rated kimberlite targets to the drilling inventory. Presently there are a total of 27 high priority kimberlite targets for ground surveys and as warranted to be drilled.

The Darnley Bay dyke swarm (723 Ma) in the project area is parallel to The Mackenzie Dyke Swarm (1270 Ma) where the Lac de Gras diamond corridor hosts two Canadian diamond producers (Ekati and Diavik), and two developing mines (Snap Lake and Tahera).

It appears that the Lac de Gras diamond corridor has been offset to the west and may continue north through Darnley Bay. The Darnley Bay dyke swarm conditions for diamond exploration are similar to those in the Lac de Gras diamond corridor. The Mackenzie Dyke Swarm might have been reworked in the Darnley Bay dyke swarm’s geological time providing the loci for both dyke intrusions and perhaps still younger dykes and kimberlite pipes of another magmatic event.