The Eastern Deeps of Voisey's Bay

In January of this year Diamond Field Resources Inc. formally announced the discovery of new reserves at the Voisey's Bay site. These reserves include the Western Extension (west of the original ovoid) and the Eastern Deeps deposit. The addition of these discoveries, combined with the original reserves, have boosted reserve estimates from 32 million tonnes to about 100 million tonnes. A recent announcement that the Eastern Deeps ore zone has been expanded further east means that this total reserve figure has probably been increased.

The Eastern Deeps discovery is of enormous significance since it implies that widespread mineralization may exist over a large area east of the original discovery site. To appreciate the significance of this, it is necessary to understand the geology of the Voisey's Bay deposit.

The Reid Brook Intrusion, named after the nearby Reid Brook, is a rock formation that resulted from the injection (intrusion) of a volume of molton rock (magma) into a space within the earth's crust. The magma cooled and crystallized to form rock - in this case - troctolite.


The original discovery was made within a narrow rock formation that opened into a broad, wine-glass shaped basin known as the ovoid. When first discovered, the origin of the ovoid was not clear; however, recent drilling has demonstrated that it is related to a geological formation known as the Reid Brook Intrusion. The rock (troctolite) which comprises this intrusion crystallized from molten magma deep within the earth. The intrusion was subsequently uplifted, tilted and eroded.

Mineralization crystallized from the magma within the Reid Brook Intrusion and, because of its denser nature, accumulated on its floor. This floor zone is now thought to be represented in the west by the ovoid deposit and to the east by the deeper level ores of the Eastern Deeps. The floor, together with its ores, continue to the east for an as yet undetermined distance.

The exciting potential that this reveals is that large parts of the Reid Brook Intrusion may contain mineralization at depth, although surface indications of its presence may be lacking. Only continued drilling will determine the ultimate extent of the ore bodies but the potential for further discoveries, as predicted by Diamond Fields and the project managers, Archean Resources, appears very high indeed.

Still to be determined is the significance and extent of the Western Extension. Since the priority at the moment appears to be on the Eastern Deeps, it may be some time before the potential of the Western Extension is realized.


The fact that total reserves now amount to 100 million tonnes or more places the Voisey's Bay discovery firmly on the international scene. The map above shows the major nickel sulphide deposits in the world. Associated tonnage and nickel grade for these deposits are displayed in the accompanying diagram. The original Voisey's Bay discovery, while of very high grade, is still relatively small in comparison to other major deposits of the world. Of particular note, however, is that within two years of the initial discovery, the tonnage estimate has more than tripled. Since the Company has not announced grades associated with the new reserves, it is not possible to position Voisey's Bay precisely on the tonnage-grade grid; however it appears likely that, at the very least, it is comparable to other large scale valuable nickel deposits in Canada, e.g., Thompson, Manitoba. It should also be noted that other world deposits have the benefit of lengthy exploration programs. Given that most of the other reserve figures shown on this map are the result of 20 years or more of exploration, the growth potential of Voisey's Bay is extremely promising.