The Iullemmeden Basin (

Berber language The Berber languages, also known as the Amazigh languages or Tamazight, are a branch of the Afroasiatic language family. They comprise a group of closely related but mostly mutually unintelligible languages spoken by Berber communities, who ar ...

: Iwellemmedden) is a major sub-Saharan inland basin in

West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

, extending about north to south and east to west. It covers western

Niger Niger, officially the Republic of the Niger, is a landlocked country in West Africa. It is a unitary state Geography of Niger#Political geography, bordered by Libya to the Libya–Niger border, north-east, Chad to the Chad–Niger border, east ...

and parts of

Algeria Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...

Mali Mali, officially the Republic of Mali, is a landlocked country in West Africa. It is the List of African countries by area, eighth-largest country in Africa, with an area of over . The country is bordered to the north by Algeria, to the east b ...

and

Nigeria Nigeria, officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of Guinea in the Atlantic Ocean to the south. It covers an area of . With Demographics of Nigeria, ...

. It is named after the

Iullemmeden The Iwellemmedan (''Iwəlləmədǎn''), also spelled Iullemmeden, Aulliminden, Ouilliminden, Lullemmeden, and Iwellemmeden, are one of the seven major Tuareg people, Tuareg tribal or clan confederations (called "''Drum groups''"). Their communit ...

, a federation of

Tuareg people The Tuareg people (; also spelled Twareg or Touareg; Endonym and exonym, endonym, depending on Tuareg languages#Subclassification, variety: ''Imuhaɣ'', ''Imušaɣ'', ''Imašeɣăn'' or ''Imajeɣăn'') are a large Berbers, Berber ethnic group, ...

who live in the central region of Niger. Its geographic range is largely coincident with the Azawagh region.Paris, 1995

Description

The area of the Iullemmeden Basin seems to have started to subside in Permo-Triassic times, and to have experienced gradual downwarping during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

times, while steadily filling with sediment. Two prominent fault trends run NNE-SSW through the center of the basin, while WSW-ENE faults trends are found in the northeast of the basin near the

Aïr Mountains The Aïr Mountains or Aïr Massif (Air Tamajeq language, Tamajăq: ''Ayǝr''; Hausa language, Hausa: Eastern ''Azbin'', Western ''Abzin'') is a triangular massif, located in northern Niger, within the Sahara. Part of the West Sa ...

Stratigraphy

The sediments from

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

times are thick, with alternating layers formed when the basin was undersea and above sea level. Potentially valuable minerals include

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

and

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

ores and

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

and

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

deposits. Niger is one of the world's largest producers of

Formations of the Iullemmeden Basin

Gwandu Formation Gwandu, also called Gando, is a town and emirate in Kebbi State, Nigeria. The seat of government for the emirate and district of this name is in Birnin Kebbi, which is the capital of Kebbi State and was capital of the historical Kingdom of Kebbi. ...

* Kalambaina Formation *

Wurno Formation Wurno is a Local Government Area in Sokoto State, Nigeria. Its headquarters is in the town of Wurno, near the Gagere River. It has an area of 685 km and a population of 180,219 at the 2023 census. The postal code A postal code (also kno ...

Taloka Formation {{For, the insect genus, Taloka (planthopper) Bhai Taloka was a GurSikh of Guru Arjan Dev, the fifth Sikh Guru. He was also a General in Nawab Ghazni Ghazni (, ), historically known as Ghaznayn () or Ghazna (), also transliterated as Ghuznee, ...

Dukamaje Formation The Dukamaje Formation is a geological formation in Niger and Nigeria whose strata date back to the Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the ge ...

* Igdaman Group * Majias Group ** Farin Doutchi Formation **

In Beceten Formation The In Beceten Formation, also Beceten or Ibecten is a Coniacian to Santonian geologic formation in the Iullemmeden Basin of Niger. It has yielded a diverse fauna and some angiosperms. Among others, it has yielded polypterifoms, urodeles, anura ...

* Zoo Baba Formation * Alanlara Formation * Tegama Group ** Farak Formation ** Echkar Formation ** Elrhaz Formation ** Tazolé Formation * Ilrhazer Group ** Tiourarén Formation ** Irhazer Shale * Téfidet Group ** Tagrezou Sandstone * Agadez GroupYoung et al., 2017, p.379 ** Assaouas Formation ** Tchirezrine Formation ** Teloua Formation * Izégouandane Group ** Moradi Formation ** Tamamait Formation ** Tejia Formation ** Izégouandane Formation

References

Bibliography

* *

Description

Stratigraphy

Formations of the Iullemmeden Basin

See also

References

Bibliography

Further reading