AFRICA SPECIAL — Gold targets overshadow Mali’s geological diversity

Extensive geological work undertaken in Mali over the past few decades has confirmed that the country is prospective for a variety of mineral resources, including gold, diamonds, platinum, uranium, copper, lead, zinc, iron, bauxite, manganese, phosphates and salt.

Notwithstanding this geological diversity, exploration efforts have largely been directed towards gold. Mali has a rich history of exploiting gold, with mining having been practised in the area since ancient times. Indeed, the wealth accumulated from gold mining led to the establishment of a series of ancient empires.

In 1989, Mali’s exported gold production was valued at a mere US$25 million.

By 1993, this had increased to US$35 million, representing 13% of the country’s total exports.

The most extensive gold-bearing regions known in Mali are found in the Birimian formation of Proterozoic age. There are several provinces with strong gold potential in the west, the south, and even the north of the country. In Bagoe, the Syama gold deposit is being mined and, in Kenieba province, the Sadiola Hill gold mine is up and running. The latter was the first major African project outside South Africa to be announced by a South African mining house (Anglo American) after decades of international isolation.

Other projects

Other advanced gold projects in the country include Loulo (900,000 oz.) and Medinandi (125,000 oz.). In the province of Yanfolila-Kalana, the dormant Kalana mine (with an estimated gold potential of between 1.3 million and 1.6 million oz.) was mined between 1985 and 1991. During this time, the Russian-assisted operation produced about 16,000 oz. gold per year. It is now being evaluated by Ashanti Goldfields (ASL-N) and JCI in a joint venture with the Malian government.

In the mid-1980s, BHP, one of the world’s largest mining companies, decided to invest in grassroots exploration opportunities in Mali. BHP-Utah, as it was then known, became interested in the Syama gold anomaly, with its large, oxidized gold target in laterites and rich gold in sulphide veins in the underlying, unoxidized Birimian rocks. After a long period of negotiation, the company finally obtained a mining permit. Randgold of South Africa has since acquired the mine.

Syama represented the beginning of an upswing in Mali’s gold industry. It was followed by the discovery of the Sadiola Hill gold anomaly, which was significant in size to attract Anglo American’s interest. Despite this flurry of interest in gold projects, the country’s other major deposits — including those of phosphates, salt and uranium — remain unexploited.

The crystalline zones of the West African craton are represented in Mali by Birimian formations and granitic intrusions and basement rocks. These formations, deposited between 2.3 billion and 1.9 billion years ago, were folded and metamorphosed in the Eburnian orogeny. They form long, narrow volcanic belts separated by vast areas of granite gneiss.

Two groups

Two principal groups can be made out. A lower group, B1, is predominantly volcanic, affected by the three tectonic phases of the Eburnian orogenic cycle. A higher group, B2, is essentially sedimentary and contains foliated pebbles of group B1 and early granitic rocks. The two Birimian groups are surmounted by one unit, the Tarkwaian, composed mainly of base deposits of the molasse type. The crystalline formations crop out mainly in the south of Mali, where they form part of the Leo ridge. The crystalline formations of the Tuareq Shield come to the surface in the northeast, where they constitute the mountain chain of the Adrar of the Iforas. The Taoudeni Basin, containing sediments of Proterozoic to Carboniferous age, forms a shelf to the West African craton. Numerous kimberlite pipes have been identified in the Birimian areas of the west.

Landlocked between Mauritania to the west and Niger to the east, Mali is among the poorest countries in the world, with 65% of its land area classified as either desert or semi-desert. Economic activity is largely confined to areas irrigated by the Niger River. About 10% of the population (estimated at 10 million) is nomadic and some 80% of the workforce is engaged in agriculture and fishing. Industrial activity is concentrated on processing farm commodities.

Mali’s economy is beginning to expand, after contracting through the early 1990s, largely because of enhanced exports and import substitute production in the wake of the 50% devaluation of its currency in January 1994.

Post-devaluation inflation appears to have peaked at 35% in 1994, and the government appears to be keeping on-track with its structural adjustment program. Mali’s gross national product (GNP) is currently US$5.4 billion, and the GNP’s real growth rate is 2.4%. French, while the official language, is less widely spoken than the local language of Bambara.

— The author is a freelance writer based in South Africa.