Foumban Shear Zone

The Foumban Shear Zone, or Central Cameroon Shear Zone (CCSZ), is a fault zone in Cameroon that has been identified with the Pernambuco fault in northeastern Brazil, which splays from the Trans-Brazilian Lineament.^[1] It is part of the Central African Shear Zone (CASZ) and dates to at least 640 million years ago. The zone was rejuvenated several times, usually with a dextral movement, before and during the opening of the South Atlantic in the Cretaceous period.^[2]

The Foumban shear zone is a series of faults associated with major mylonite zones, a segment of the CASZ. The CASZ can be traced from the Sudan to the Adamawa plateau, after which its path is obscured by volcanoes. Based on reconstruction of the configuration of South America before it separated from Africa, the zone can be identified with the Pernambuco fault.^[3] The shear zone underlies a chain of active volcanoes, called the Cameroon Volcanic Line. In August 1986 a magnitude 5 earthquake with epicenter near Lake Nyos indicated that the shear zone may be again reactivating.^[4]

References

↑ J D Fairhead; Nasreddine Bournas; M Chaker Raddadi (2007). "The Role of Gravity and Aeromagnetic Data in Mapping Mega Gondwana Crustal Lineaments: the Argentina - Brazil – Algeria (ABA) Lineament" (PDF). SEG. Retrieved 2011-01-30.
↑ C. Dorbath; L. Dorbath; D. Fairhead; G. W. Stuart (1986). "A teleseismic delay time study across the Central African Shear Zone in the Adamawa region of Cameroon, West Africa" (PDF). Geophys. J. R. astr. Soc. pp. 751–766. Retrieved 2011-01-31.
↑ G. W. STUART; J.D. FAIRHEAD; L. DORBATH; C. DORBATH (1985). "CRUSTAL STRUCTURE OF THE ADAMAWA PLATEAU CAMEROON" (PDF). Rev. Sci. et Tech. Sér Sci. Terre. Retrieved 2011-01-31.
↑ "Quake may have triggered Nyos disaster". New Scientist. 12 Feb 1987. Retrieved 2011-01-31.

Coordinates: 6°37′0″N 12°52′0″E / 6.61667°N 12.86667°E / 6.61667; 12.86667

Major African geological formations

Plates	African Plate Somali Plate Madagascar Plate Seychelles Plate

Cratons and shields	Arabian-Nubian Shield Congo Craton Kaapvaal Craton Kalahari Craton Saharan Metacraton Tanzania Craton Tuareg Shield West African Craton Zimbabwe Craton

Shear zones	Aswa Dislocation Broodkop Shear Zone Central African Shear Zone Chuan Shear Zones Foumban Shear Zone Mwembeshi Shear Zone Todi Shear Zone Western Meseta Shear Zone

Orogens	Alpide Orogen Cape Fold Belt Damara Orogen East African Orogen Eburnean Orogen Gondwanide Orogen Kuunga Orogen Mauritanide Belt Pan-African orogens Terra Australis Orogen

Rifts	Afar Triangle Anza trough Bahr el Arab rift Benue Trough Blue Nile rift East African Rift Gulf of Suez Rift Lamu Embayment Melut Basin Muglad Basin Red Sea Rift Sangha Aulacogen Atbara rift White Nile rift

Sedimentary basins	Angola Basin Aoukar Blue Nile Basin Chad Basin Congo Basin Douala Basin El Djouf Foreland Karoo Basin Gabon Basin Iullemmeden Basin Kufra Basin Murzuq Basin Niger Delta Basin Ogaden Basin Orange River basin Ouled Abdoun Basin Owambo Basin Reggane Basin Rio del Rey Basin Sirte Basin Somali Coastal Basin Taoudeni basin Tanzania Coastal Basin Tindouf Basin Turkana Basin

Mountain ranges	Aïr Mountains Atlas Mountains Aurès Mountains Bambouk Mountains Blue Mountains Cameroon line Central Pangean Mountains Chaillu Mountains Drakensberg Ethiopian Highlands East African mountains Great Escarpment Great Karas Mountains Guinée forestière Imatong Mountains Jebel Uweinat Loma Mountains Mandara Mountains Marrah Mountains Mitumba Mountains Nuba Mountains Rif Mountains Rwenzori Mountains Sankwala Mountains Serra da Leba Serra da Chela Teffedest Mountains Tibesti Mountains

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