MINING IN AFRICA SPECIAL — Tanzania draws gold, diamond

An atmosphere of political stability and economic reform, coupled with underexplored and underdeveloped mineral resources, is attracting an ever growing number of Canadian mining companies to Tanzania. Most of the junior explorers are coming in search of gold and diamonds.

The majority of known gold occurrences in Tanzania are of Precambrian age and occur in similar geological settings to those in Southern Africa, Canada and Western Australia. Recorded cumulative gold production from the Tanzanian craton is about 55.8 tonnes.

Tan Range Resources (ASE) has been involved in gold exploration and mining in Tanzania since 1990. The company has been granted seven gold concessions comprising 577 sq. km. These gold properties were acquired primarily for their potential to develop into large-tonnage, open-pit, heap-leachable operations.

AGL Gold Mining, a wholly owned subsidiary of Minprotech Mining (ASE), is exploring a number of gold properties in the northwestern part of the country. Most of the mining licences are located in the Lake Victoria Goldfields region and cover greenstone terrains which have seen little or no present-day exploration.

Within a year of its inception, Patrician Gold Mines (ASE) has signed two agreements to earn interests in eight gold properties throughout Tanzania. Most of the work done to date has focused on the Ikungu property on the eastern shore of Lake Victoria, about 80 km from Mwanza. A hole drilled last fall into the Forest Reef, a thick exhalite horizon, intersected 22.3 grams gold per tonne over 4.45 metres. Additional work is being carried out. One of the more aggressive gold players in the region is Pangea Goldfields (TSE), which holds 42 mining licences covering about 3,400 sq. km. Recent exploration programs have returned significant gold values on the company’s Bulyanhulu South and Golden Ridge properties, south of Mwanza. At the Golden Ridge property, drilling was carried out to evaluate the gold potential of the oxidized portion of the outcropping sections of an extensive and highly folded banded iron formation (BIF), which has been traced geophysically over a linear strike length of 25 km. Some of the better reverse circulation (RC) drill results include 8.9 grams over 21 metres and 6.9 grams over 30 metres. So far, about 9 km of BIF have been tested. The remaining 16 km of formation is under laterite cover and will be tested in the near future.

On the Bulyanhulu South property, seven major gold targets have been identified through geochemical and geophysical surveys. Gold values up to 9 grams have been returned in soil samples. Pangea says that these results compare favorably to those obtained on the property of Sutton Resources (VSE) to the north, which contains an estimated resource of up to 1.5 million oz. Last fall, Kinross Gold (TSE) and affiliated junior East Africa Gold (VSE) completed a share purchase and option agreement with privately owned East African Mines (EAM). The deal effectively gives Kinross and East Africa (formerly Consolidated Kassan Resources) control of EAM, which controls the mineral rights to about 1,000 sq. km in 12 separate properties within the Lake Victoria Goldfields region in northwestern Tanzania.

The most advanced of these properties is the Buckreef project, a joint venture owned 80% by EAM and 20% by the Tanzanian government. EAM recently completed a 53-hole RC drill program on the property, which confirmed the presence of a potentially open-pitable resource in three separate zones along a northeast-trending shear zone that extends for more than 2.3 km.

Based on the RC results, and on previous diamond drilling, drill-indicated and inferred open-pit resources are calculated to be 1.12 million tonnes grading 4 grams. In addition to the open-pit resource, drill intersections below the 50-metre level suggest a downdip, underground potential along the shear zone. The average grade and width of 10 intersections between 50 metres and 110 metres in the Main zone is 5.41 grams across 8.5 metres. Although the country contains 300 known kimberlites, only the Mwadui pipe has been commercially exploited. Since its discovery in 1940 by J.T. Williamson, Mwadui has yielded more than 17 million carats. The majority of the diamonds are of gem quality, with many fancy colors. Smaller-scale diamond mining has also been carried out on six other sites.

Tan Range has been granted six diamond concessions, most of which are in close proximity to the Williamson mine. Three of these concessions are known to have produced diamonds in the past, and two are active with small-scale, non-mechanized hand-mining undertaken by the local population. Partners Argosy Mining (VSE) and Reunion Mining (the latter is a 32% owned subsidiary of TSE-listed Caledonia Mining), hold an 11,000-sq.-km diamond exploration licence near Mwanza. The companies are testing some 60 odd geophysical targets thought to represent kimberlite pipes.

Serengeti Diamonds (VSE) recently reached an agreement with its partners, Tanzania Diamond Mines and Rose Quartz Minerals of Australia, to extend funding dates for exploration expenditures on their diamond projects until June 15, 1995. Serengeti can earn a 40% interest in the joint venture, which holds 14.9 million hectares of diamond licences throughout Tanzania. Other Tanzanian diamond explorers include Bakertalc (ME) and Pure Gold Resources (TSE).