|
Ontong Java Plateau
The Ontong Java Plateau (OJP) is a massive oceanic plateau located in the southwestern Pacific Ocean, north of the Solomon Islands. The OJP was formed around (Ma) with a much smaller volcanic event around 90 Ma. Two other southwestern Pacific plateaus, Manihiki and Hikurangi, now separated from the OJP by Cretaceous oceanic basins, are of similar age and composition and probably formed as a single plateau and a contiguous large igneous province together with the OJP. When eruption of lava had finished, the Ontong Java–Manihiki–Hikurangi plateau covered 1% of Earth's surface and represented a volume of of basaltic magma. This "Ontong Java event", first proposed in 1991, represents the largest volcanic event of the past 200 million years, with a magma eruption rate estimated at up to per year over 3 million years, several times larger than the Deccan Traps. The smooth surface of the OJP is punctuated by seamounts such as the Ontong Java Atoll, one of the largest atolls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Plateau
An oceanic or submarine plateau is a large, relatively flat elevation that is higher than the surrounding relief with one or more relatively steep sides. There are 184 oceanic plateaus in the world, covering an area of or about 5.11% of the oceans. The South Pacific region around Australia and New Zealand contains the greatest number of oceanic plateaus (see map). Oceanic plateaus produced by large igneous provinces are often associated with hotspots, mantle plumes, and volcanic islands — such as Iceland, Hawaii, Cape Verde, and Kerguelen. The three largest plateaus, the Caribbean, Ontong Java, and Mid-Pacific Mountains, are located on thermal swells. Other oceanic plateaus, however, are made of rifted continental crust, for example the Falkland Plateau, Lord Howe Rise, and parts of Kerguelen, Seychelles, and Arctic ridges. Plateaus formed by large igneous provinces were formed by the equivalent of continental flood basalts such as the Deccan Traps in India and the Snak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisville Hotspot
The Louisville hotspot is a volcanic hotspot responsible for the volcanic activity that has formed the Louisville Ridge in the southern Pacific Ocean. Location The Louisville hotspot is believed to lie close to the Pacific-Antarctic Ridge, although its exact location is uncertain. Geological history The Louisville hotspot has produced the Louisville Ridge, which is one of the longest seamount chains on Earth, stretching some Vanderkluysen, L.; Mahoney, J. J.; Koppers, A. A.; and Lonsdale, P. F. (2007)Geochemical Evolution of the Louisville Seamount Chain American Geophysical Union, Fall Meeting 2007, abstract #V42B-06. from the Pacific-Antarctic Ridge to the Tonga Trench where it subducts under the Indo-Australian Plate as part of the Pacific Plate. The Louisville hotspot is believed to have been active since at least 78.8 ± 1.3 Ma based on age of the oldest seamount (Osbourn ). This duration is comparable to that of the Hawaiian-Emperor seamount chain, although the rate of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Drilling Program
The Ocean Drilling Program (ODP) was a multinational effort to explore and study the composition and structure of the Earth's oceanic basins. ODP, which began in 1985, was the successor to the Deep Sea Drilling Project initiated in 1968 by the United States. ODP was an international effort with contributions of Australia, Germany, France, Japan, the United Kingdom and the ESF Consortium for Ocean Drilling (ECOD) including 12 further countries. The program used the drillship ''JOIDES Resolution'' on 110 expeditions (legs) to collect about 2,000 deep sea cores from major geological features located in the ocean basins of the world. Drilling discoveries led to further questions and hypotheses, as well as to new disciplines in earth sciences such as the field of paleoceanography. In 2004 ODP transformed into the Integrated Ocean Drilling Program (IODP). See also * Project Mohole * Deep Sea Drilling Program * Integrated Ocean Drilling Program * Allison Guyot Allison Guyot (fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malaita
Malaita is the primary island of Malaita Province in Solomon Islands. Malaita is the most populous island of the Solomon Islands, with a population of 161,832 as of 2021, or more than a third of the entire national population. It is also the second largest island in the country by area, after Guadalcanal. A tropical and mountainous island, Malaita's river systems and tropical forests are being exploited for ecosystem stability by keeping them pristine. The largest city and provincial capital is Auki, on the northwest coast and is on the northern shore of the Langa Langa Lagoon. The people of the Langa Langa Lagoon and the Lau Lagoon on the northeast coast of Malaita call themselves ''wane i asi'' ‘salt-water people’ as distinct from ''wane i tolo'' ‘bush people’ who live in the interior of the island. South Malaita Island, also known as ''Small Malaita'' and ''Maramasike'' for 'Are'are language, Areare speakers and Malamweimwei known to more than 80% of the islanders, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Makira
The island of Makira (also known as San Cristobal and San Cristóbal) is the largest island of Makira-Ulawa Province in the Solomon Islands. It is third most populous island after Malaita and Guadalcanal, with a population of 55,126 as of 2020. The island is located east of Guadalcanal and south of Malaita. The largest and capital city is Kirakira. History The first recorded sighting by Europeans of Makira was by the Spanish expedition of Álvaro de Mendaña in June 1568. More precisely the sighting and also landing in San Cristobal was due to a local voyage that set out from Guadalcanal in a small boat, in the accounts the brigantine ''Santiago'', commanded by Alférez Hernando Enriquez and having Hernán Gallego as pilot. They charted it as ''San Cristóbal''.Brand, Donald D. ''The Pacific Basin: A History of its Geographical Explorations'' The American Geographical Society, New York, 1967, p.133. Education The Stuyvenberg Rural Training Centre is a rural boarding c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guadalcanal
Guadalcanal (; indigenous name: ''Isatabu'') is the principal island in Guadalcanal Province of Solomon Islands, located in the south-western Pacific, northeast of Australia. It is the largest island in the Solomon Islands by area, and the second by population (after Malaita). The island is mainly covered in dense tropical rainforest and has a mountainous hinterland. Guadalcanal's first charting by westerners was under the Spanish expedition of Álvaro de Mendaña in 1568. The name comes from the village of Guadalcanal, in the province of Seville, in Andalusia, Spain, birthplace of Pedro de Ortega Valencia, a member of Mendaña's expedition. During 1942–43, it was the scene of the Guadalcanal Campaign and saw bitter fighting between Japanese and US troops. The Americans were ultimately victorious. At the end of World War II, Honiara, on the north coast of Guadalcanal, became the new capital of the British Solomon Islands Protectorate. Geography Guadalcanal is the lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accretionary Prism
An accretionary wedge or accretionary prism forms from sediments accreted onto the non-subducting tectonic plate at a convergent plate boundary. Most of the material in the accretionary wedge consists of marine sediments scraped off from the downgoing slab of oceanic crust, but in some cases the wedge includes the erosional products of volcanic island arcs formed on the overriding plate. An accretionary complex is a current (in modern use) or former accretionary wedge. Accretionary complexes are typically made up of a mix of turbidites of terrestrial material, basalts from the ocean floor, and pelagic and hemipelagic sediments. For example, most of the geological basement of Japan is made up of accretionary complexes. Materials within an accretionary wedge Accretionary wedges and accreted terranes are not equivalent to tectonic plates, but rather are associated with tectonic plates and accrete as a result of tectonic collision. Materials incorporated in accretionary wedges inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bougainville Island
Bougainville Island (Tok Pisin: ''Bogenvil'') is the main island of the Autonomous Region of Bougainville, which is part of Papua New Guinea. It was previously the main landmass in the German Empire-associated North Solomons. Its land area is . The population of the whole province, including nearby islets such as the Carterets, is approximately 300,000 (2019 census). The highest point is Mount Balbi, on the main island, at . The much smaller Buka Island, , lies to the north, across the wide Buka Strait. Even though the strait is narrow, there is no bridge across it, but there is a regular ferry service between the key settlements on either side. The main airport (or airstrip) in the north is in the town of Buka. Bougainville is the largest island in the Solomon Islands archipelago. Most of the islands in this archipelago (which are primarily concentrated in the southern and eastern portions of it) are part of the politically independent Solomon Islands. Two of these islands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Georgia Islands
The New Georgia Islands are part of the Western Province of Solomon Islands. They are located to the northwest of Guadalcanal. The larger islands are mountainous and covered in rain forest. The main islands are New Georgia, Vella Lavella, Kolombangara (a dormant volcano), Ghizo, Vangunu, Rendova and Tetepare. They are surrounded by coral reefs and include the largest saltwater lagoon in the world: Marovo lagoon. Another famous location is Kennedy Island where the future United States president, John F. Kennedy, spent three days stranded during World War II. Several of the islands were scenes of fighting in the war. The main towns are Gizo, Munda and Noro. The main industries are forestry and fishing. One of the smaller New Georgia islands, Ranongga, was lifted three metres (10 ft.) out of the Pacific Ocean by the 2007 Solomon Islands earthquake, causing an expansion of its shoreline by up to 70 metres all around. Northwest Solomonic languages are spoken on the isla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonic Uplift
Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics. While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal thickening (such as mountain building events), changes in the density distribution of the crust and underlying mantle, and flexural support due to the bending of rigid lithosphere. Tectonic uplift results in denudation (processes that wear away the earth's surface) by raising buried rocks closer to the surface. This process can redistribute large loads from an elevated region to a topographically lower area as well – thus promoting an isostatic response in the region of denudation (which can cause local bedrock uplift). The timing, magnitude, and rate of denudation can be estimated by geologists using pressure-temperature studies. Crustal thickening Crustal thickening has an upward component of motion and often occurs when continental crus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable beddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
%2C_by_Mason_&_Co..jpg "Click for more on -> Malaita")
