Hi, welcome to this hall on the importance of Plateaux, Type And characteristics.
Table Of Contents
- Definition of Plateau
- Characteristics of Plateau
- Types of Plateau
- Mode of formation
- Importance of Plateaux
- Disadvantages of Plateau
- Revision Questions
Definition of Plateau
A plateau is an elevated upland with extensive level surface and usually descending steeply to the surrounding lowland.
Characteristics of Plateau
- Plateau are elevated upland.
- They have extensive flat or level surface which usually descend sharply to the surrounding lowland.
- They have gentle slopes.
- They are often referred to as table land because of their flat or level surface.
- Plateaux are tabular in shape, steep-sided with rough and irregular surfaces.
- They have narrow valleys and sometimes form hydrological centers.
- Mesas and buttes may be present.
- Most plateaux are relics of ancient mountain ranges.
Types of Plateau
There are three types of plateau based on their mode of formation. These are tectonic plateau, volcanic or (lava) plateaux and dissected or residual plateaux.
(a) Tectonic Plateaux
Mode Of Formation: These plateaux are formed as a result of earth movement which causes the uplift of some areas and the depression of others. Uplifted areas of land or undulating land form tectonic plateaux and the depressed area form basins.
Tectonic plateaux are of two types
- Table land: The uplifted areas of the level land slope down to surrounding lower land.
- Intermont: The uplifted areas of the level land slope up or are enclosed by fold mountains. Examples of a tectonic plateaux is deccan plateaux (India). Some may be titled e.g, Mesetal (central Iberia), or faulted e.g, Harz of Germany. Examples of intermont plateaux are Tibetan plateau between Himalayas and Kunlun and Bolivian plateau between two ridges of the Andes.
(b) Volcanic or (lava) Plateaux
Mode of formation: These Plateaux are formed as a result of volcanic activity. When there is a crack or fissure, pressure is released. Molten lava comes out of the earth’s crust through a vent and spread out in successive layers. The lava cools and solidifies to form volcanic or lava plateau. Examples are Antrim plateau of Northern Ireland, Colombia snake plateau and Biu plateau (Nigeria).
(c) Dissected Plateaux
Mode of formation: Dissected or residual plateaux originated from either tectonic of volcanic plateau. They may also be formed from accident fold mountains which have been eroded and weathered. Also, they may be formed from Highlands along whose edges rivers have carved out deep narrow valleys (dissected plateau). The high and extensive plateaus are gradually worn down. Examples are middle Rhine plateaux, Fouta Djallon highlands, Jos and Enugu plateaux and Kumasi plateau. They commonly look like series of ridges interspersed by plain land.
Importance Of Plateaux Or Uses
- Sources of valuable minerals: Some Plateaux are rich in minerals, e.g. iron ore and gold copper.
- For favorable settlements: Plateaux in the tropical lands have cooler climate and favored settlement, e.g. Jos plateau.
- Centers of tourism: Some Plateaux favor tourism, especially those in the tropics.
- Grazing land for animals: Some Plateaux have some grasses and legumes favorable to the rearing of ruminant animals.
- Arable farming: Some Plateaux are good for farming, e.g, Deccan plateau is deal for tea and jute cultivation.
- Sources of rivers: Many plateaux are sources of big rivers, e.g, Fouta Djallon highlands.
- Formation Of rainfall: Some plateau server source of formulation of orographic or relief rainfall
- Sources of hydro-electric power (H.E.P): Water falls at plateaux edges could serve as source of hydro-electric power.
Disadvantages Of Plateaux
- Some plateaux are barriers to communication as they prevent roads, railway and airport construction.
- Some plateaux are associated with erosion which tend to reduce or prevent serious farming activities.
Revision Questions
- (a) What is plateau? (b) Describe the mode of formation of (i) tectonic plateau (ii) Dissected Plateaux (iii) volcanic plateau.
- Outline the importance of plateaux to man.
- (a) State five characteristics of plateau (b) Discuss the types of Plateau and give two examples each.