Formation Of East African Rift Valley
- Plates moving northward. On one side of the East African Rift lies the larger Nubian tectonic Plate which makes up the continental crust of Africa and the Arabian Plate.
- Ethiopian Rift development. ...
- Distinct rift basins. ...
- Rift Valley landscapes. ...
- Most noticeable feature. ...
What leads to the formation of a rift valley?
Jun 14, 2017 · The East African Rift valley was formed due to tectonics. Tectonic forces act in opposite directions driving plates apart creating tensional faults. Continued movement of the plates result in a rift valley. Up welling of magma associated with its formation usually buid up to form volcanes which include Kilimanjaro and Kenya mountains.
What are the stages of Rift Valley Formation?
Apr 21, 2020 · The East African Rift Valley, as the region is known, formed where the Somalian and Nubian plates are pulling away from the Arabian Plate. The eastern branch of the rift passes through Ethiopia and Kenya, and the western branch forms a giant arc from Uganda to Malawi.
How did Rift Valley in East Africa form?
Jan 01, 2020 · How did the East African Rift Valley form? The East African Rift Valley, as the region is known, formed where the Somalian and Nubian plates are pulling away from the Arabian Plate. The eastern branch of the rift passes through Ethiopia and Kenya, and the western branch forms a giant arc from Uganda to Malawi. Click to see full answer.
What is the primary cause of Rift Valley Formation?
How is A Rift Valley Formed The African Rift probably started around 40 million years ago as a simple hotspot in the Afar region. This hotspot, which coincides with an area of active volcanoes, would have peeked out from under the Africa plate and forced the plate to form a dome that cracked in three directions, forming a “Y”.
When was the East African Rift Valley formed?
The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a larger Great Rift Valley that extended north to Asia Minor.
What is the East African Rift and what caused it?
The East African Rift is one of the great tectonic features of Africa, caused by fracturing of the Earth's crust.Apr 1, 2012
How is a rift valley formed give one example of a rift valley?
A rift valley is formed by the submergence of a big landmass between two high block mountains, e.g. the Rhine river flows through a rift valley in its middle course.
How rift valley lakes are formed?
More than a billion years ago, for instance, the North American plate began a rifting process. A triple junction formed in the middle of the young continent, and deep rift valley developed. Freshwater drained and collected in this rift valley, creating a lake.Jun 15, 2015
How are rift valleys created?
Rift valleys are found both on land and at the bottom of the ocean, where they are created by the process of seafloor spreading. Rift valleys differ from river valley s and glacial valley s in that they are created by tectonic activity and not the process of erosion.
How is the Baikal Rift Valley formed?
The Baikal Rift Valley is formed by a divergent plate boundary, where the Amur plate is slowly tearing itself away from the Eurasian plate, and has been doing so for about 25 million years. The Amur plate is moving eastward at a rate of about 4 to 5 millimeters (.16 to .2 inch) a year.
What is the name of the plate that carries the continent of Africa?
Throughout the East African Rift, the continent of Africa is splitting in two. The African plate, sometimes called the Nubian plate, carries most of the continent, while the smaller Somali plate carries Horn of Africa. The two major rift valley systems of the East African Rift are the Gregory Rift and the Western Rift.
How wide are rift valleys?
Over millions of years, the Mid-Atlantic Ridge has formed rift valleys as wide as 15 kilometers (9 miles). In the Pacific Ocean, the East Pacific Rise has created rift valleys where the Pacific plate is separating from the North American plate, Cocos plate, Nazca plate, and Antarctic plate.
Where are the deepest rift valleys?
Many of Earth’s deepest rift valleys are found underwater, dividing long mountain ranges called mid-ocean ridge s. As tectonic plates move away from one another at mid-ocean ridges, molten rock from the mantle may well up and harden as it contacts the frigid sea, forming new oceanic crust at the bottom of the rift valley.
What is the Western Rift?
The Western Rift, also called the Albertine Rift, includes many of the African Great Lakes. The Western Rift is one of the most biodiverse regions in Africa, featuring a narrow corridor of highland forest s, snow-capped mountains, savanna s, and chains of lake s and wetland s.
What is the result of a triple junction?
Two arms of the triple junction can split to form an entire ocean. The third, “failed rift” or aulacogen, may become a rift valley. The Atlantic Ocean, for instance, is a result of a triple junction that started in what is now the Gulf of Guinea on the west coast of Africa.
What causes the African Rift Valley to fill with water?
The stretching causes the crust to thin and drop, or subside, below sea level, and eventually, the valley may fill with water. At this time, there are three locations in the African Rift Valley that lie below sea level; they are the Afar Depression and the lake beds of Lakes Malawi and Tanganyika.
How are rift valleys created?
A rift valley can be defined as a valley that is created by the splitting of the earth's crust. Rift valleys differ from river or glacial valleys in that they are created by tectonic activity rather than surface climatic forces.They are often narrow with flat floors and steep walls, and most of them occur in oceanic crust.
What is the East African Rift System?
The African Rift, also known as the East African Rift System (or EARS), is actually a system of rifts created by the separating of the Nubian Plate and the Somalian Plate , which together comprise the African Plate of the African continent. The following is a map of East Africa showing historically important volcanoes as ...
What causes the crust to pull apart?
One hypothesis is that volcanic activity creates hot areas under the crust, causing bulges in the crust and uprising in those areas. This results in the stretching of the crust between these bulges (in this case, the Ethiopian and Kenyan Bulges) to stretch and pull apart.
Why is the Earth's crust constantly reforming?
The earth's crust is constantly reforming due to the movement of tectonic plates. Tectonic plates are sections of the earth's surface layer, or crust and upper mantle that move on the currents of the underlying mantle.
What are the two highest mountains in Africa?
The two highest mountains in Africa, Mounts Kilimanjaro and Kenya, are both volcanic cones. Much of the sheer walls and mountains in the rift region are caused not by subsidence, but by faulting, or the breaking of the earth's rocky crust.
Where did the most of the fossils of humans come from?
Many of the fossils of human ancestors come from the East African Rift Valley. Parts of the East African Rift are nicknamed the Cradle of Mankind, and the most likely location for the birth of human ancestors and humans. Let's review.
What are the narrow rift segments of the East African Rift System?
Today, the narrow rift segments of the East African Rift system form zones of localized strain. These rifts are the result of the actions of numerous normal faults which are typical of all tectonic rift zones.
What are the volcanoes in the East African Rift Zone?
The East African Rift Zone includes a number of active and dormant volcanoes, among them: Mount Kilimanjaro, Mount Kenya, Mount Longonot, Menengai Crater, Mount Karisimbi, Mount Nyiragongo, Mount Meru and Mount Elgon, as well as the Crater Highlands in Tanzania. Although most of these mountains lie outside ...
What is the active continental rift zone?
Active continental rift zone in East Africa . A map of East Africa showing some of the historically active volcanoes (as red triangles) and the Afar Triangle (shaded at the center), which is a so-called triple junction (or triple point) where three plates are pulling away from one another: the Arabian Plate and two parts ...
What is the rift zone?
A narrow zone, the rift is a developing divergent tectonic plate boundary where the African Plate is in the process of splitting into two tectonic plates, called the Somali Plate and the Nubian Plate, at a rate of 6–7 mm (0.24–0.28 in) per year. The rift system consists of three microplates, the Victoria Microplate to the north, ...
What are the features of the Albertine Rift?
An artificial rendering of the Albertine Rift, which forms the western branch of the East African Rift. Visible features include (from background to foreground): Lake Albert, the Rwenzori Mountains, Lake Edward, the volcanic Virunga Mountains, Lake Kivu, and the northern part of Lake Tanganyika. The African continental crust is generally cool ...
Where is the Afar rift?
To the north of the Afar Triple Junction, the rift follows one of two paths: west to the Red Sea Rift or east to the Aden Ridge in the Gulf of Aden . The EAR runs from the Afar Triple Junction in the Afar Triangle of Ethiopia through eastern Africa, terminating in Mozambique. The EAR transects through Ethiopia, Kenya, Uganda, Rwanda, Burundi, ...
Where are the plumes of Ethiopian lavas?
The varying geochemical signatures of a suite of Ethiopian lavas suggest multiple plume sources: at least one of deep mantle origin, and one from within the subcontinental lithosphere. In accordance, a 2014 study 2014 compares the geochemical signature of rare earth isotopes from xenoliths and lava samples collected in the EAR. The results corroborate the coexistence of a superplume “common to the entire rift” with another mantle material source being either of subcontinental type or of mid-ocean ridge type.
