The Biu Plateau is a highland area in Northeastern

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

containing many recently extinct

volcano A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Ear ...

es. It covers about and has an average elevation of . The plateau lies between the Upper Benue Basin to the south and the Chad Basin to the north. High points are Wade Hill at above sea level and Wiga Hill, at well over . The plateau is the source of many tributaries of the

Gongola River The Gongola River is in northeastern Nigeria, the principal tributary of the Benue River. The upper course of the river as well as most of its tributaries are seasonal streams, but fill rapidly in August and September. The Gongola rises on the east ...

, which have cut deep gorges. To the north the plateau slopes gently to the Bauchi plains and the Chad Basin. There is evidence of early volcanic activity in the area during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

, which ended about 66 million years ago. However, the plateau was built around the end of the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, and the bulk of the rocks are

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...

s that have erupted from small vents or fissures, and then spread in a thin layer over wide areas. Activity resumed in the Quaternary with thin flows of lava issuing from small cinder cones and filling the valleys. Most of the basalts date between 7 and 2 million years ago, but some are less than a million years old. The plateau includes many small pyroclastic cones caused by explosions when water penetrated downward and came into contact with fresh lava. There are a number of well-preserved volcanic cones rising above the Plateau along a NNW-SSE axis in the Miringa volcanic zone. Some geologists consider that the volcanic activity in the Biu Plateau is associated with the activity in the Cameroon line to the south.

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* {{Coord, 10, 40, 42, N, 12, 0, 19, E, display=title Geology of Nigeria Lava plateaus Volcanoes of Nigeria

See also

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