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Fold Mountains
Fold mountains are formed by the effects of folding on layers within the upper part of the Earth's crust. Before the development of the theory of plate tectonics and before the internal architecture of thrust belts became well understood, the term was used to describe most mountain belts but has otherwise fallen out of use. Formation Fold mountains form in areas of thrust tectonics, such as where two tectonic plates move towards each other at convergent plate boundary. When plates and the continents riding on them collide or undergo subduction (that is – ride one over another), the accumulated layers of rock may crumple and fold like a tablecloth that is pushed across a table, particularly if there is a mechanically weak layer such as salt. Since the less dense continental crust "floats" on the denser mantle rocks beneath, the weight of any crustal material forced upward to form hills, plateaus or mountains must be balanced by the buoyancy force of a much greater volume f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zagros 1992
The Zagros Mountains are a mountain range in Iran, northern Iraq, and southeastern Turkey. The mountain range has a total length of . The Zagros range begins in northwestern Iran and roughly follows Iran's western border while covering much of southeastern Turkey and northeastern Iraq. From this border region, the range continues southeast to the waters of the Persian Gulf. It spans the southern parts of the Armenian highlands, and the whole length of the western and southwestern Iranian plateau, ending at the Strait of Hormuz. The highest point is Mount Dena, at . Geology The Zagros fold and thrust belt was mainly formed by the collision of two tectonic plates, the Eurasian Plate and the Arabian Plate. This collision mainly happened during the Miocene (about 25–5 mya or million years ago) and folded the entirety of the rocks that had been deposited from the Paleozoic (541–242 mya) to the Cenozoic (66 mya – present) in the passive continental margin on the Arabia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nappes
In geology, a nappe or thrust sheet is a large sheetlike body of rock that has been moved more than or above a thrust fault from its original position. Nappes form in compressional tectonic settings like continental collision zones or on the overriding plate in active subduction zones. Nappes form when a mass of rock is forced (or "thrust") over another rock mass, typically on a low angle fault plane. The resulting structure may include large-scale recumbent folds, shearing along the fault plane,Twiss, Robert J. and Eldridge M. Moores, ''Structural Geology,'' W. H. Freeman, 1992, p. 236 imbricate thrust stacks, fensters and klippes. The term stems from the French word for ''tablecloth'' in allusion to a rumpled tablecloth being pushed across a table. History Nappes or nappe belts are a major feature of the European Alps, Dinarides, Carpathians and Balkans. Since the 19th century many geologists have uncovered areas with large-scale overthrusts. Some of these were subst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of Ghana
Ghana is a West African country in Africa, along the Gulf of Guinea. Ghana encompasses plains, low hills, rivers, Lake Volta, the world's largest artificial lake, Dodi Island and Bobowasi Island on the south Atlantic Ocean coast of Ghana. Ghana can be divided into four different geographical ecoregions. The coastline is mostly a low, sandy shore backed by plains and Shrubland, scrub and intersected by several rivers and streams. The northern part of Ghana features high plains. South-west and south-central Ghana is made up of a forested plateau region consisting of the Ashanti Region, Ashanti Highland, uplands and the Kwahu Plateau. The hilly Akwapim-Togo Mountain range, ranges are found along Ghana's eastern international border. The Volta Basin takes up most of south-central Ghana and Ghana's highest point is Mount Afadja which is and is found in the Akwapim-Togo Mountain range, ranges. The climate is tropical climate, tropical and the Dahomey Gap, eastern coastal belt is war ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormuz Formation
The Hormuz Formation, Hormuz Series, Hormuz Evaporites or Hormuz Group is a sequence of evaporites that were deposited during the Ediacaran (Late Neoproterozoic) to Early Cambrian, a period previously referred to as the Infra-Cambrian. Most exposures of this sequence are in the form of emergent salt diapirs within anticlines of the Zagros fold and thrust belt. As a result of their involvement in post-depositional salt tectonics, the internal stratigraphy of the sequence is relatively poorly understood. They are the lateral equivalent of the evaporite-bearing Ara Group in the South Oman Basin. Distribution The Hormuz Formation is known from a wide area of the Zagros Mountains and around and beneath the Persian Gulf. Two main depositional basins have been recognised, the North Gulf and South Gulf Basins, separated by the Qatar Arch. The basins were formed as a result of extensional tectonics towards the end of the Pan-African Orogeny. The main structure formed during this period were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cambrian
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new convergent plate boundaries and continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in life on Earth; prior to the Period, the majority of living organisms were small, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it was not until the Cambrian that fossil diversity seems to rapidly in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoproterozoic
The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic geologic eon, eon, spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era and succeeded by the Paleozoic era of the Phanerozoic eon, and is further subdivided into three geologic period, periods, the Tonian, Cryogenian and Ediacaran. One of the most severe glaciation events known in the geologic record occurred during the Cryogenian period of the Neoproterozoic, when global ice sheets may have reached the equator and created a "Snowball Earth" lasting about 100 million years. The earliest fossils of complex life are found in the Tonian period in the form of ''Otavia'', a primitive sponge, and the earliest fossil evidence of metazoan evolutionary radiation, radiation are found in the Ediacaran period, which included the namesaked Ediacaran biota as well as the oldest definitive cnidarians and bilaterians in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zagros Fold And Thrust Belt
The Zagros fold and thrust belt (Zagros FTB) is an approximately long zone of deformed crustal rocks, formed in the foreland of the collision between the Arabian plate and the Eurasian plate. It is host to one of the world's largest petroleum provinces, containing about 49% of the established hydrocarbon reserves in fold and thrust belts (FTBs) and about 7% of all reserves globally. Plate tectonic setting The Zagros FTB is formed along a section of the plate boundary that is subject to oblique convergence with the Arabian plate moving northwards with respect to the Eurasian plate at about 3 cm per year. The degree of obliqueness reduces southwards along the Zagros, with the collision becoming near orthogonal within the Fars domain. The relative movement between the plates is only partly taken up within the Zagros, the remainder is taken up by deformation in the Alborz mountains and the Lesser Caucasus Mountains to the north of the Iranian plateau and along the zone f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detachment Fold
A detachment fold, in geology, occurs as layer parallel thrusting along a decollement (or detachment) develops without upward propagation of a fault; the accommodation of the strain produced by continued displacement along the underlying thrust results in the folding of the overlying rock units. As a visual aid, picture a rug on the floor. By placing your left foot on one end and pushing (with your left foot) towards the other end of the rug, the rug slides across the floor ( decollement) and folds upward (detachment fold). Figure 1, is a generalized representation of the geometry assumed by a detachment fault. Definitions Detachment folding occurs as strain imposed on a mechanically weak layer or incompetent unit, such as shale or salt, or at the boundary between an incompetent and more competent unit, induces resistance from the units resulting in folding typically observed in the competent unit.Homza, T. and W. Wallace (1995) Geometric and kinematic models for detachment fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zagros Mountains
The Zagros Mountains are a mountain range in Iran, northern Iraq, and southeastern Turkey. The mountain range has a total length of . The Zagros range begins in northwestern Iran and roughly follows Iran's western border while covering much of southeastern Turkey and northeastern Iraq. From this border region, the range continues southeast to the waters of the Persian Gulf. It spans the southern parts of the Armenian highlands, and the whole length of the western and southwestern Iranian plateau, ending at the Strait of Hormuz. The highest point is Mount Dena, at . Geology The Zagros fold and thrust belt was mainly formed by the collision of two tectonic plates, the Eurasian Plate and the Arabian Plate. This collision mainly happened during the Miocene (about 25–5 mya or million years ago) and folded the entirety of the rocks that had been deposited from the Paleozoic (541–242 mya) to the Cenozoic (66 mya – present) in the passive continental margin on the Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alps
The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. The Alpine arch extends from Nice on the western Mediterranean Sea, Mediterranean to Trieste on the Adriatic Sea, Adriatic and Vienna at the beginning of the Pannonian Basin. The mountains were formed over tens of millions of years as the African and Eurasian tectonic plates collided. Extreme shortening caused by the event resulted in marine sedimentary rocks rising by thrust fault, thrusting and Fold (geology), folding into high mountain peaks such as Mont Blanc and the Matterhorn. Mont Blanc spans the French–Italian border, and at is the highest mountain in the Alps. The Alpine region area contains 82 peaks higher than List of Alpine four-thousanders, . The altitude and size of the range affect the climate in Europe; in the mountain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foreland Basin
A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric flexure. The width and depth of the foreland basin is determined by the flexural rigidity of the underlying lithosphere, and the characteristics of the mountain belt. The foreland basin receives sediment that is eroded off the adjacent mountain belt, filling with thick sedimentary successions that thin away from the mountain belt. Foreland basins represent an endmember basin type, the other being rift basins. Accommodation (the space available for sediments to be deposited) is provided by loading and downflexure to form foreland basins, in contrast to rift basins, where accommodation space is generated by lithospheric extension. Types of foreland basin Foreland basins can be divided into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
