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Geology of Africa

The African continent consists of five old bedrock areas, cratons, which are welded together with younger mountain chains. 57 percent of the continent has exposed Precambrian rocks to the surface, and the rest has younger deposits on this bedrock. Africa took its present form when South America, Antarctica and Australia disassociated themselves from the great Gondwana continent less than 200 million years ago.

Archaic bedrock (2.5 billion years and older)

2017 AfricaThe oldest bedrock in Africa is the so-called granite-gneiss-greenstone belts in the Kaapvaal, Zimbabwe and Congo cratons. See all countries in the continents of Africa on Countryaah. They date from up to 3.6 billion years ago. In the greenstone belts, the volcanic rock has comatite as a particularly characteristic rock. This rock is originally a lava formed on the seabed. After a period of throngs of huge volumes of granite towards the end of the archaeological and tectonic stabilization, the area was worn down and covered with sandstones, which contain economically important gold and uranium deposits, including at Witwatersrand in South Africa. In silica slate(chert) from greenstone belts in the Transvaal, fossils of unicellular algae have been found, which is one of the oldest traces of life known in the world.

Proterozoic bedrock (from 2.5 billion to about 545 million years old)

At the end of the Precambrian 950–550 million years ago, several elongated fold belts were formed (Pan-African episode). Towards the end of the Precambrian, large, wide recesses formed, which were filled with sedimentary and volcanic deposits, including in the Transvaal, Congo and West Africa basins.

The Transvaal contains economically important iron ore, and the West African basin contains moraine conglomerate, confidence, which points to an ice age in this area at the end of the Precambrian (as in Norway).

Younger bedrock

Between 545 and 248 million years ago, smaller folding belts were built, including in South Africa (Cape Belt), Morocco ( Anti-Atlas Belt ) and Mauritania (Mauritania Belt). These correspond to the Caledonian and Hercynian mountain range folds in Europe.

200–300 million years ago, huge floods of the volcanic rock erupted basally in South Africa, Namibia and East Africa ( Karroo basalts). These large column eruptions are likely to be related to the beginning of the Great Gondwana continent. In Cretaceous, very special and yet little understood volcanic phenomena took place, producing diamond-bearing kimberlite pipes in central and southern Africa.

100 to 40 million years ago, northwestern parts of the continent took part in the alpine mountain range folding, which resulted from a clash between the African and European plates. This provided the Atlas Mountains, which are part of the alpine folding zone. In the east, the Red Sea opened during a tertiary along a rift between the African and Arab land masses. A similar rift has now formed through East Africa ( East African rift system or "graben") from Lake Malawi in the south, through East Africa to Ethiopia and on to the Jordan Valley. Today there is active volcanism (including the Kilimanjaro volcano, among others), which is the continent's highest mountain, 5895 meters above sea level. and Mt. Kenya, 5199 meter asl). If this rift zone continues to burst, one must wait for the sea to penetrate and the eastern part to become an island. What one sees by the Red Sea and the East African Rift system are probably early stages in the formation of the world sea.

Africa - wildlife

The wildlife of North Africa is similar to that of Europe and northern Asia. Here are deer, steelworms and bumblebees - animal groups that are missing from sub-Saharan Africa. The area is considered the Palarctic region.

The rest of the continent has a distinctive fauna and, together with Madagascar, constitutes the Afrotropical region, which is best known for its many large mammals: African elephant, white and black rhino, hippopotamus, lion, zebra, giraffe, coffee buffalo and not least the numerous species of antelopes. Africa is the continent with the largest species of large ungulates. The region is also characterized by a large number of mammalian families that are not found anywhere else, such as octopus mice, golden moles and ground pigs. The bird fauna is not unique, although there are some endemic families, such as mouse birds and banana eaters. African bird life is characterized by winter influx of migratory birds from the north. In South Africa, penguins live. Among the reptiles, especially crocodile and the product are conspicuous, but there are also many snake species, among others. a. Several toxic species such as mamba, cobra and viper.

Among the approx. 2,000 species of freshwater fish are found in old groups of bony fish: bikir, bald eagle and African lungfish. The large species richness of cichlids in i.a. Lake Victoria, Tanzania and Malawi are also notable. In each lake there are up to several hundred closely related species, but each with their distinctive habitat.

Wildlife in the African rainforests is not as rich as in South American and Southeast Asian. The savannah, in turn, houses a very species-rich fauna, which among other things. includes most wild game species that attract tourists and hunters.

In the desert areas there is a relatively species-rich wildlife; in particular, the Namib Desert is home to a wealth of specially adapted insects and other invertebrates. Sahara wildlife is more species poor, which is probably related to the relatively young age of the desert.

The Afrotropical fauna has many features in common with the tropical Asian fauna (eg elephants and rhinos). However, certain African animal groups (eg carpal salmon) have their closest relatives in tropical Central and South America. In the southernmost part of Africa, some groups of invertebrates are closely related to species from New Zealand, Australia and southern South America. This pattern of propagation is interpreted as the result of continental drift caused by plate tectonics.

Madagascar belongs geographically to Africa, but the island's wildlife is very different from African and is described under Madagascar.

Countries in Africa
  1. Algeria
  2. Angola
  3. Benin
  4. Botswana
  5. Burkina Faso
  6. Burundi
  7. Cameroon
  8. Cabo Verde
  9. Central African Republic
  10. Chad
  11. Comoros
  12. Democratic Republic of the Congo
  13. Djibouti
  14. Egypt
  15. Equatorial Guinea
  16. Eritrea
  17. Eswatini
  18. Ethiopia
  19. Gabon
  20. Gambia
  21. Ghana
  22. Guinea
  23. Guinea-Bissau
  24. Ivory Coast
  25. Kenya
  26. Lesotho
  27. Liberia
  28. Libya
  29. Madagascar
  30. Malawi
  31. Mali
  32. Mauritania
  33. Mauritius
  34. Morocco
  35. Mozambique
  36. Namibia
  37. Niger
  38. Nigeria
  39. Republic of the Congo
  40. Rwanda
  41. Sao Tome and Principe
  42. Senegal
  43. Seychelles
  44. Sierra Leone
  45. Somalia
  46. South Africa
  47. South Sudan
  48. Sudan
  49. Tanzania
  50. Togo
  51. Tunisia
  52. Uganda
  53. Western Sahara
  54. Zambia
  55. Zimbabwe

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