Biu Plateau
Encyclopedia
The Biu Plateau is a highland area in Northeastern Nigeria
containing many recently extinct volcano
es. It covers about 5200 square kilometre and has an average elevation of 700 m (2,296.6 ft). The plateau lies between the Upper Benue Basin to the south and the Chad Basin to the north. High points are Wade Hill at 775 m (2,542.7 ft) above sea level and Wiga Hill, at well over 800 m (2,624.7 ft). The plateau is the source of many tributaries of the Gongola River
, 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
, which ended about 65 million years ago. However, the plateau was built around the end of the Miocene
, and the bulk of the rocks are Pliocene
basalt
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.
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
containing many recently extinct volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
es. It covers about 5200 square kilometre and has an average elevation of 700 m (2,296.6 ft). The plateau lies between the Upper Benue Basin to the south and the Chad Basin to the north. High points are Wade Hill at 775 m (2,542.7 ft) above sea level and Wiga Hill, at well over 800 m (2,624.7 ft). The plateau is the source of many tributaries of the Gongola River
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....
, which have cut deep gorges. To the north the plateau slopes gently to the Bauchi
Bauchi State
Bauchi State is a State in northern Nigeria. Its capital is the city of Bauchi. The state was formed in 1976 when the former North-Eastern State was broken up...
plains and the Chad Basin
Chad Basin
The Chad Basin, also known as the Lake Chad Basin, is a large lowland area in north-central Africa. In all directions from the center of this area the elevation changes are gentle. The Chad Basin is an endorheic basin - its water does not flow into any ocean...
.
There is evidence of early volcanic activity in the area during the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, which ended about 65 million years ago. However, the plateau was built around the end of the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
, and the bulk of the rocks are Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
s that have erupted from small vents or fissures, and then spread in a thin layer over wide areas. Activity resumed in the Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
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
Cameroon line
The Cameroon line is a chain of volcanoes.It includes islands in the Gulf of Guinea and mountains that extend along the border region of eastern Nigeria and western Cameroon, from Mount Cameroon on the Gulf of Guinea north and east towards Lake Chad....
to the south.