In North Africa reserves of iron ore are concentrated in the Atlas Mountains and in the western Sahara. Egypt, however, has medium-grade reserves, of which the most important are at Al-Baḥriyyah Oasis. The ore deposits in Morocco and Tunisia, which were once of considerable importance, have been severely depleted. Africa’s most significant iron reserves are to be found in western and Southern Africa. It is the sedimentary Precambrian rocks, particularly in western Africa, that have proved the basis of Africa’s role as a major world producer of iron ore. The most significant deposits are in Liberia in the Bomi Hills, Bong and Nimba ranges, and Mano valley; in the extension into Guinea of the Nimba–Simandou ranges, where hematites have been located; in Nigeria and Mauritania, which have large deposits of low-grade ore; and in Gabon, where extensive reserves are present in the northeast. In Southern Africa most iron ore reserves lie in South Africa itself. The chief deposits are at Postmasburg, in the Bushveld Complex, at Thabazimbi, and in the vast low-grade deposits of Pretoria. There are also substantial reserves in Zimbabwe.
Africa’s reserves of minerals used as ferroalloys in the steel industry are even more striking than its enormous share of world iron ore reserves. This is particularly true of chromium. Almost the entire world reserve of chromium is found in Southern Africa and, to a much lesser extent, in western and northeastern Africa. The highest concentrations are found in Zimbabwe, at Great Dyke. South Africa contains the largest deposits of chromite. As compared with these two sources, reserves elsewhere in Africa are relatively small.
Manganese reserves are also considerable. In South Africa reserves of contained manganese are found in the Kalahari Manganese Field and elsewhere. The Mouanda deposit in southeastern Gabon is thought to be among the largest in the world. Ghana is another important source of manganese, having both low-grade and high-grade reserves. Elsewhere in western Africa, manganese deposits are situated in Burkina Faso and Côte d’Ivoire, as well as in the Democratic Republic of the Congo and in Cameroon. In North Africa manganese is found in Morocco and Algeria.
Africa’s contribution to world resources of other ferroalloys is, by comparison, insignificant. Nickel is of some importance, occurring in other metalliferous ores in Southern Africa.
Most of Africa’s copper is contained in the Central African Copperbelt, stretching across Zambia and into the Katanga (Shaba) area of the Democratic Republic of the Congo. Accompanying minerals vary with the geologic layer, but cobalt dominates. Outside the Copperbelt a number of countries have lesser but still significant reserves of copper.
Only Nigeria, the Democratic Republic of the Congo, and South Africa contain tin reserves of any significance. Although it is difficult to consider Africa’s reserves of lead and zinc separately, of the two, lead ores are considerably more widespread. North Africa is the largest traditional producing region. African reserves of zinc metal are located along the Moroccan-Algerian frontier, in the Copperbelt in the Democratic Republic of the Congo, in Nigeria, in Zambia, and in Namibia.
Africa has about one-fourth of the world’s reserves of bauxite, the chief aluminum ore. Virtually all of this occurs in a major belt of tropical laterite stretching some 1,200 miles from Guinea to Togo. The largest reserves are in Guinea.
Half of the world reserves of cobalt can be found in the Democratic Republic of the Congo. A continuation of the geologic formation into Zambia gives the country sizable reserves of cobalt content. The only other deposit of any importance is found in Morocco.
The titanium ores, ilmenite and rutile, are widely distributed in Africa but are rarely considered as minable reserves. A major source is the Sherbro deposit in Sierra Leone. Almost all of Africa’s antimony resources lie in the Murchison Range of South Africa. The major concentrations of beryllium are in Madagascar, Mozambique, the Democratic Republic of the Congo, Zimbabwe, Rwanda, Uganda, and South Africa. The principal sources of cadmium are in Namibia and the Democratic Republic of the Congo. Deposits of mercury are restricted to North Africa, notably to Tunisia and, more particularly, Algeria.
Gold and allied metals are widely disseminated, reaching their greatest concentrations in South Africa, where reserves of gold probably constitute about half of the world total. Gold is also found in Zimbabwe, in the Democratic Republic of the Congo, and in Ghana. There are numerous alluvial sources of gold in Burundi, Côte d’Ivoire, and Gabon. South Africa has the most important deposit of platinum of the world’s market economies. Silver reserves of the continent are not important.
Africa contains a major share of world reserves of tantalum, and the Democratic Republic of the Congo has most of these reserves. African reserves of niobium (columbium; a steel-gray metallic element resembling tantalum in its chemical properties that is used in alloys) are relatively small. Nigeria, however, is an important world producer.
One of Africa’s many sources of zirconium (a metallic element resembling titanium chemically) is the Jos Plateau in Nigeria. Greater reserves, however, are contained in deposits on the Senegal coast; on the east coast of South Africa; in Madagascar; at Sherbro, Sierra Leone; and in the Nile delta.
Another rare metal of which Africa contains a majority of world reserves is germanium, concentrated in the Democratic Republic of the Congo and in Namibia. Africa also has large deposits of lithium, the largest of which are found in the Democratic Republic of the Congo. Nonmetallic deposits
Clays are widespread and are found in North Africa, where brick and pottery clays occur in Algeria and Morocco; in western and central Africa, where clays are located in Togo (ceramic), the Central African Republic, and Côte d’Ivoire (ceramic); and in East and Southern Africa.
Kaolin (china clay) occurs in Algeria. Outside North Africa it is widespread. In western Africa it occurs most notably in Nigeria’s Jos Plateau, as well as in Mali, Ghana, and Guinea. Similar deposits occur in central and East Africa, as well as in Southern Africa.
Bentonite (a clay formed from decomposed volcanic ash, which is able to absorb large quantities of water and to expand to several times its usual size) is found in the Moroccan Atlas Mountains and in Tanzania, Kenya, and South Africa. The continent’s principal reserve of fuller’s earth (an absorbent clay) is in Morocco.
Economically important mica deposits occur primarily in Southern Africa (South Africa, Zimbabwe, and Tanzania) and in Madagascar.
Africa has none of the world’s major reserves of sulfur. It reaches economic concentrations only in South Africa’s Witwatersrand, in Zambia’s Copperbelt, and in Morocco. Large quantities of sodium deposits remain to be evaluated. Sodium chloride is the principal salt, the largest deposit being in the Danakil Plain of Ethiopia. The principal sources of salt in Africa, however, are inland or coastal basins, from which it is extracted by the evaporation of salt water. Major coastal reserves of this type lie along the North African Mediterranean coast and along the Red Sea and Indian Ocean coasts of East Africa and Madagascar. Inland, the chief reserves are in the Oran Sebkha, a salt pan region in Algeria; in Botswana around Lake Makarikari; and in Uganda.
Another important sodium mineral is natron, or sodium carbonate. Natron is more limited in occurrence, but Africa contains several significant deposits. It is found in Lake Magadi, Kenya, and in Lake Natron, Tanzania, as well as in western Africa, where beds have been deposited from the waters of Lake Chad.
North Africa has been a traditional exporter of phosphates, and western Africa has large reserves. Morocco and Western Sahara together have vast reserves. The Río de Oro region in Western Sahara contains huge deposits, and a major development at Bu-Craa has been established. Algeria and Tunisia also have reserves. To the east, phosphate-bearing sediments outcrop on the Red Sea coast. The Thiès deposit in Senegal is of particular interest in constituting the world’s only source of aluminum (as opposed to calcium) phosphate. Other phosphate deposits occur in Togo, Nigeria, Tanzania, Uganda, and Malawi.