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Mascarene Basin
The Mascarene Basin is an oceanic basin in the western Indian Ocean. It was formed as the Plate tectonics, tectonic plate of the Indian Plate, Indian subcontinent pulled away from the Madagascar Plate about 66–90 Mya, following the breaking up of the Gondwana supercontinent. The Mascarene Basin is bounded on the west by the island of Madagascar, i.e. the Precambrian Madagascar Massif. It is separated from the Western and Eastern Somali Basins to the north and northeast by the island arc from the northern tip of Madagascar, the Farquhar Group, Farquhar Islands, the Amirante Islands and Amirante Plateau, the Seychelles Plateau and the Mascarene Plateau. To the southwest and south it is separated from the Madagascar Basin by a continuation of the island arc through Mauritius Island and Reunion Island, the Mauritius Fracture Zone, a fracture zone trending approximately NE-SW, located east of Mauritius Island, and the northwestern edge of the Madagascar Ridge. The approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana Breakup
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic, Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia (continent), Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the Accretion (geology), accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous, Carboniferous Period, it merged with Laurasia t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Basin
In hydrology, an oceanic basin (or ocean basin) is anywhere on Earth that is covered by seawater. Geologically, ocean basins are large geologic basins that are below sea level. Most commonly the ocean is divided into basins following the continents distribution: the North and South Atlantic (together approximately 75 million km2/ 29 million mi2), North and South Pacific (together approximately 155 million km2/ 59 million mi2), Indian Ocean (68 million km2/ 26 million mi2) and Arctic Ocean (14 million km2/ 5.4 million mi2). Also recognized is the Southern Ocean (20 million km2/ 7 million mi2). All ocean basins collectively cover 71% of the Earth's surface, and together they contain almost 97% of all water on the planet. They have an average depth of almost 4 km (about 2.5 miles). Definitions of boundaries Boundaries based on continents ''"Limits of Oceans and Seas"'',International Hydrographic Organization (IHO), (1953): Limits of Oceans and Seas, Internat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Ocean
The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by the Southern Ocean or Antarctica, depending on the definition in use. Along its core, the Indian Ocean has some large marginal or regional seas such as the Arabian Sea, Laccadive Sea, Bay of Bengal, and Andaman Sea. Etymology The Indian Ocean has been known by its present name since at least 1515 when the Latin form ''Oceanus Orientalis Indicus'' ("Indian Eastern Ocean") is attested, named after Indian subcontinent, India, which projects into it. It was earlier known as the ''Eastern Ocean'', a term that was still in use during the mid-18th century (see map), as opposed to the ''Western Ocean'' (Atlantic Ocean, Atlantic) before the Pacific Ocean, Pacific was surmised. Conversely, Ming treasure voyages, Chinese explorers in the Indian Oce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Plate
The Indian Plate (or India Plate) is a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian Plate broke away from the other fragments of Gondwana , began moving north and carried Insular India with it. It was once fused with the adjacent Australian Plate to form a single Indo-Australian Plate, and recent studies suggest that India and Australia have been separate plates for at least 3 million years and likely longer. The Indian Plate includes most of modern South Asia (the Indian subcontinent) and a portion of the basin under the Indian Ocean, including parts of South China and western Indonesia, and extending up to but not including Ladakh, Kohistan and Balochistan. Plate movements Until roughly , the Indian Plate formed part of the supercontinent Gondwana together with modern Africa, Australia, Antarctica, and South America. Gondwana broke up as these continents drifted apart at different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar Plate
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Madagascar (the fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of its wildlife is endemic. Human settlement of Madagascar occurred during or before the mid first millennium AD by Austronesian peoples, presumably arriving on outrigger canoes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana (and Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercontinent
In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which leaves room for interpretation and is easier to apply to Precambrian times. To separate supercontinents from other groupings, a limit has been proposed in which a continent must include at least about 75% of the continental crust then in existence in order to qualify as a supercontinent. Supercontinents have assembled and dispersed multiple times in the geologic past (see table). According to modern definitions, a supercontinent does not exist today; the closest in existence to a supercontinent is the current Afro-Eurasian landmass, which covers approx. 57% of Earth's total land area. The last time the continental landmasses were near to one another was 336 to 175 million years ago as the supercontinent, Pangaea. The positions of con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farquhar Group
The Farquhar Group belong to the Outer Islands of the Seychelles, lying in the southwest of the island nation, more than southwest of the capital, Victoria, on Mahé Island. Area The total land area of all islands in the group is less than , but the total area of the atolls measures about . The group consists of two atolls and one separate island. In addition, there are a couple of submerged reefs in the area: #Farquhar Atoll (with two larger and about eight smaller islets) #Providence Atoll (with 2 islets, Providence Island and Cerf Island) # St. Pierre Island # Wizard Reef # Umzinto Bank (submerged) # Bulldog Bank (submerged) # McLeod Bank (submerged) Population There is one settlement, located on Île du Nord (North Island) of Farquhar Atoll. There is an abandoned village on Providence Island of Providence Atoll. There are records of Maldivian mariner presence in the group from the 20th century, when a trading vessel from southern Maldives lost its course and reached Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amirante Islands
The Amirante Islands (''Les Amirantes'') are a group of coral islands and atolls that belong to the Outer Islands of the Seychelles. They stretch about 155 km from the African Banks (African Islands) in the north to Desnœufs (Isle des Noeufs) in the south, all on the shallow Amirantes Bank (Amirantes Plateau, with depths of mostly 25 to 70 m), except the main island Île Desroches in the east, and submerged Lady Denison-Pender Shoal at the northern end. 90 km south of the Amirante Islands is Alphonse Group, the closest group of islands, which are sometimes considered part of the Amirantes. History The Amirantes were discovered by Vasco da Gama on his second voyage of exploration in 1503, and later named "Ilhas do Almirante" (Admiral Islands). Previous knowledge of the islands by Arab and Indian traders is possible. The islands were claimed by Sieur Michel Blin for France in 1802. By the Treaty of Paris (1814), the islands were passed officially to the British, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mascarene Plateau
The Mascarene Plateau is a submarine plateau in the Indian Ocean, north and east of Madagascar. The plateau extends approximately , from Seychelles in the north to Réunion in the south. The plateau covers an area of over of shallow water, with depths ranging from , plunging to to the abyssal plain at its edges. It is the second-largest oceanic plateau in the Indian Ocean after the Kerguelen Plateau. Geography The northern part of the Mascarene Plateau includes the Agaléga Islands and the Seychelles Islands. The southern part of the Mascarene Plateau includes Hawkins Bank, the Mascarene Islands, Nazareth Bank, the Saya de Malha Bank, and the Soudan Banks. The Mascarene Islands are the mountainous islands of the Cargados Carajos Shoals, Mauritius, Réunion, and Rodrigues. Geology The Indian subcontinent was at one time next to the east coast of Seychelles, but seafloor spreading has moved the landmass to its current position, where it has collided and fused with the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
