|
Afar Triple Junction
The Afar Triple Junction (also called the Afro-Arabian Rift System) is located along a divergent plate boundary dividing the Nubian, Somali, and Arabian plates. This area is considered a present-day example of continental rifting leading to seafloor spreading and producing an oceanic basin. Here, the Red Sea Rift meets the Aden Ridge and the East African Rift. The latter extends a total of from the Afar Triangle to Mozambique. The connecting three arms form a triple junction. The northernmost branching arm extends north through the Red Sea and into the Dead Sea, while the eastern arm extends through the Gulf of Aden and connects to the Mid-Indian Ocean ridge further to the east. Both of these rifting arms are below sea level and are similar to a mid-ocean ridge. The third rifting arm runs south extending around through the countries of Kenya, Uganda, the Democratic Republic of Congo, Rwanda, Burundi, Tanzania, Zambia, Malawi and, finally, Mozambique. This southern rifting arm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenya
) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , official_languages = Constitution (2009) Art. 7 ational, official and other languages"(1) The national language of the Republic is Swahili. (2) The official languages of the Republic are Swahili and English. (3) The State shall–-–- (a) promote and protect the diversity of language of the people of Kenya; and (b) promote the development and use of indigenous languages, Kenyan Sign language, Braille and other communication formats and technologies accessible to persons with disabilities." , languages_type = National language , languages = Swahili , ethnic_groups = , ethnic_groups_year = 2019 census , religion = , religion_year = 2019 census , demonym = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthenosphere
The asthenosphere () is the mechanically weak and ductile region of the upper mantle of Earth. It lies below the lithosphere, at a depth between ~ below the surface, and extends as deep as . However, the lower boundary of the asthenosphere is not well defined. The asthenosphere is almost solid, but a slight amount of melting (less than 0.1% of the rock) contributes to its mechanical weakness. More extensive decompression melting of the asthenosphere takes place where it wells upwards, and this is the most important source of magma on Earth. It is the source of mid-ocean ridge basalt (MORB) and of some magmas that erupted above subduction zones or in regions of continental rifting. Characteristics The asthenosphere is a part of the upper mantle just below the lithosphere that is involved in plate tectonic movement and isostatic adjustments. It is composed of peridotite, a rock containing mostly the minerals olivine and pyroxene. The lithosphere-asthenosphere boundary is con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Crust
Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called ''sial'' because its bulk composition is richer in aluminium silicates (Al-Si) and has a lower density compared to the oceanic crust, called ''sima'' which is richer in magnesium silicate (Mg-Si) minerals. Changes in seismic wave velocities have shown that at a certain depth (the Conrad discontinuity), there is a reasonably sharp contrast between the more felsic upper continental crust and the lower continental crust, which is more mafic in character. The continental crust consists of various layers, with a bulk composition that is intermediate (SiO2 wt% = 60.6). The average density of continental crust is about , less dense than the ultramafic material that makes up the mantle, which has a density of around . Continental crust is also less dense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithosphere
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust (geology), crust and the portion of the upper mantle (geology), mantle that behaves elastically on time scales of up to thousands of years or more. The crust and upper mantle (Earth), upper mantle are distinguished on the basis of chemistry and mineralogy. Earth's lithosphere Earth's lithosphere, which constitutes the hard and rigid outer vertical layer of the Earth, includes the crust and the uppermost mantle. The lithosphere is underlain by the asthenosphere which is the weaker, hotter, and deeper part of the upper mantle. The lithosphere–asthenosphere boundary is defined by a difference in response to stress. The lithosphere remains rigid for very long periods of geologic time in which it deforms elastically and through brittle failure, while the asthenosphere deforms viscously and accommodates strain through plasticity (physics), pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rift
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates. ''Failed rifts'' are the result of continental rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malawi
Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeast, and Mozambique to the east, south and southwest. Malawi spans over and has an estimated population of 19,431,566 (as of January 2021). Malawi's capital (and largest city) is Lilongwe. Its second-largest is Blantyre, its third-largest is Mzuzu and its fourth-largest is its former capital, Zomba. The name ''Malawi'' comes from the Maravi, an old name for the Chewa people who inhabit the area. The country is nicknamed "The Warm Heart of Africa" because of the friendliness of its people. The part of Africa now known as Malawi was settled around the 10th century by migrating Bantu groups . Centuries later, in 1891, the area was colonised by the British and became a protectorate of the United Kingdom known as Nyasaland. In 1953, it became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zambia
Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are the Democratic Republic of the Congo to the north, Tanzania to the northeast, Malawi to the east, Mozambique to the southeast, Zimbabwe and Botswana to the south, Namibia to the southwest, and Angola to the west. The capital city of Zambia is Lusaka, located in the south-central part of Zambia. The nation's population of around 19.5 million is concentrated mainly around Lusaka in the south and the Copperbelt Province to the north, the core economic hubs of the country. Originally inhabited by Khoisan peoples, the region was affected by the Bantu expansion of the thirteenth century. Following the arrival of European exploration of Africa, European explorers in the eighteenth century, the British colonised the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and the Indian Ocean to the east; Mozambique and Malawi to the south; Zambia to the southwest; and Rwanda, Burundi, and the Democratic Republic of the Congo to the west. Mount Kilimanjaro, Africa's highest mountain, is in northeastern Tanzania. According to the United Nations, Tanzania has a population of million, making it the most populous country located entirely south of the equator. Many important hominid fossils have been found in Tanzania, such as 6-million-year-old Pliocene hominid fossils. The genus Australopithecus ranged across Africa between 4 and 2 million years ago, and the oldest remains of the genus ''Homo'' are found near Lake Olduvai. Following the rise of '' Homo erectus'' 1.8 million years ago, humanity spread ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burundi
Burundi (, ), officially the Republic of Burundi ( rn, Repuburika y’Uburundi ; Swahili language, Swahili: ''Jamuhuri ya Burundi''; French language, French: ''République du Burundi'' ), is a landlocked country in the Great Rift Valley at the junction between the African Great Lakes region and East Africa. It is bordered by Rwanda to the north, Tanzania to the east and southeast, and the Democratic Republic of the Congo to the west; Lake Tanganyika lies along its southwestern border. The capital cities are Gitega and Bujumbura, the latter being the country's largest city. The Great Lakes Twa, Twa, Hutu and Tutsi peoples have lived in Burundi for at least 500 years. For more than 200 of those years, Burundi was an independent Kingdom of Burundi, kingdom, until the beginning of the 20th century, when it became a German colony. After the First World War and German Revolution of 1918–19, Germany's defeat, the League of Nations "mandated" the territory to Belgium. After the Secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Burundi")