Mount Oku, or Kilum Mountain, is the largest volcano in the Oku Massif, in the Cameroon Volcanic Line, located in the Oku region of the

Western High Plateau The Western High Plateau, Western Highlands or Bamenda Grassfields is a region of Cameroon characterised by high relief, cool temperatures, heavy rainfall and savanna vegetation. The region lies along the Cameroon line and consists of mounta ...

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the ...

. It is the second highest mountain in mainland

Central Africa Central Africa is a subregion of the African continent comprising various countries according to different definitions. Angola, Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Co ...

. The

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

rises to above sea level, and is cut by a large

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

Geology

Some of the rocks have ages starting from 24.9 to 22.1 million years ago, but much more recent activity has occurred. The mountain is built of

basaltic 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 ...

and hawaiitic lavas, succeeded by

trachytes Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and alk ...

, and then by large volumes of

trachytic Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and alk ...

and

rhyolitic Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals ( phenocrysts) in an otherwise fine-grained groundmass. The ...

ignimbrite Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surro ...

s with a thickness of up to 1,000 m. Further trachytic lavas,

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

s and

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of ...

s were produced, and the most recent phase produced

pyroclastic Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...

cones and explosion craters. One of these craters holds

Lake Oku Lake Oku is a crater lake on the Bamenda Plateau in the Northwest Region of Cameroon. It is located at on Mount Oku, and is completely surrounded by cloud forest. The lake lies in an explosion crater formed in the last phase of development of ...

, from which flows of basalt issued in the north, and of rhyolitic and phonolitic lavas in the south.

Ecology

A small

sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

community with associated wetland plant species was discovered at 2,900 m in 1997, near the summit of the volcano, the highest sphagnum bog in West Africa. This site includes several plant species

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the Kilum-Ijim area, and is of extremely high conservation importance. The 200 km² of forests of the Kilum-Ijim area around the mountain form the largest remaining patch of montane forest in

West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali ...

, an important habitat for endemic species of animals and plants. The forest is at risk, since it is surrounded by a high density of human settlements.

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

and the Ministry of the Environment and Forestry are jointly operating the Kilum-Ijim Forest Project, which aims to conserve the forest biome, maintain biodiversity and ensure sustainable reuse. Most of the area within the Kilum-Ijim boundary is above 2000 metres in height, and consists of montane forest mixed with montane grassland and

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

communities. At lower elevations, most of the submontane forest has been cleared for agriculture. Based on satellite images, between 1958 and 1988 about half of the forest was lost, although regeneration began soon after the conservation project was started in 1987. Since then there has been steady recovery of the forest reserve, which is under the direct management of the Kilum-Ijim communities. Endangered endemic species found exclusively on Mount Oku include the Mount Oku hylomyscus, the Dieterlen's brush-furred mouse, the Lake Oku clawed frog,

Crotaphatrema lamottei ''Crotaphatrema lamottei'', the Mount Oku caecilian or Lamotte's caecilian, is a species of caecilian in the family Scolecomorphidae. It is endemic to Mount Oku in Cameroon. The specific name ''lamottei'' honours , French biologist. There is so ...

the Mount Oku caecilian and the toad ''

Wolterstorffina chirioi ''Wolterstorffina chirioi'' is a species of toad in the family Bufonidae. It is endemic to Cameroon and known only from Mount Oku, its type locality. The specific name ''chirioi'' honours Laurent Chirio, a herpetologist from the National Museu ...

''. The montane grassland above the forest belt is home to the endemic Mittendorf's striped grass mouse.

References

External links

"Mont Oku, Cameroon" on Peakbagger
{{Authority control Volcanoes of Cameroon Cameroonian Highlands forests

Geology

Ecology

See also

References

External links