Certain areas of Africa have played an important economic role in the most ancient times. Ancient Egypt was a great political and commercial center for thousands of years, and the province of Africa for several centuries was a storehouse of wheat and oil for the Roman Empire. From the Middle Ages, the ephemeral Sudanese states maintained lively economic contacts with the countries on the Mediterranean coast.. Caravan routes led through the Sahara desert, with which slaves were transported, salt, gold, Ivory, palm and peanuts, olive oil, cotton seeds, sezam, coffee, wine, bananas, dates or barley. Search work has proven, that the African land, considered for centuries to be devoid of mineral wealth, it hides many valuable minerals. Currently, Africa has a significant share in the global extraction of manganese ore, chromowej, uranium, wanadu, copper, gold, diamonds, tin and phosphates, and also platinum, cobalt, titanium, bauxites, zinc, lead and crude oil.
Uniformity of wealth
The occurrence of mineral wealth results from the geological structure and lithology, which in the case of Africa is fairly uniform. Almost the entire continent is made up of the Precambrian African Platform, the base of which is made of crystalline metamorphic rocks folded in the ancient geological past, and then repeatedly equated. In some places, large fragments of this surface are exposed as massive shields – West Saharan and West Sudanese (Ahaggar i Tibesti), Central African and South African (Cameroon massifs, Tanzania, Rodezji and Katangi). There are sunken areas filled with younger sediments between the elevated zones (dating from the Cambrian to the Pleistocene), forming layers 0 thicknesses from several hundred to several thousand meters in places. In terms of geological diversity, the continent is divided into the following areas: Northeast Africa, Western, Central and South.
Much of this territory is occupied by the Sahara Desert. The shape of its surface is characterized by extensive depressions, called pools, closed by rocky rapids. To the south, the Libyan Basin is surrounded by the Central Saharan threshold with the Tibesti Massif, and the Upper Nile Basin – on the threshold of Bajjuda, Abyssinian highlands, Azande doorstep and the Marra Mountains. Libya and Algeria's oil fields, the richest in this part of the continent, are located within the above-mentioned sedimentation depressions (Zarzajtin-Zaltan). Old, flowing crystalline rocks form the southern boundary of Northeast Africa and are found in Sudan, in the Abyssinian Plateau and in southern Libya.
This part of the continent has a not very diversified geological structure, and the relief is generally monotonous. The outcrops of the Precambrian subsoil appear in the landscape as uplands with a slightly undulating relief, in places diversified with island mountains built of rocks most resistant to weathering. Only the clear edges of the highlands, in addition, it is cut by river valleys, from a distance they give the impression of mountains. West Africa is known for its rich mineral deposits. Already in the Middle Ages, large amounts of gold were transported from here through the Sahara to the Mediterranean Sea. They are mainly mined from conglomerates and Precambrian sandstones. Many metal ores are also found in old rocks: uranium (in Niger), iron (m.in. liveried, Sierra Leone, Guinea, Mauritania), manganese (in Ghana, in the Ivory Coast), copper (in Mauritania), tin and niobium (in Nigeria), and also boxites (in Guinea, Sierra Leone, Ghana). Diamonds have been found in many countries (m.in. liveried, Sierra Leone, Ghana, Guinea, in the Ivory Coast). Rich oil reserves have been discovered in the sedimentary rocks of the coastal zone (largest in Nigeria) and phosphates (in Senegal, Togo). On the other hand, the riches of the interior of the valleys of the Middle Niger and Chad are much less recognized.