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Intraplate Deformation
Intraplate deformation is the folding, breaking, or flow of the Earth's crust within plates instead of at their margins. This process usually occurs in areas with especially weak crust and upper mantle (Earth), upper mantle, such as the Tibetan Plateau (Figure 1). Intraplate deformation brings another aspect to Plate tectonics, plate tectonic theory. Crustal deformation processes The theory of plate tectonics states that the Earth's lithosphere (crust and upper mantle) is made up of rigid plates that "float" on top of the asthenosphere (lower mantle) and move relative to one another. As the plates move, the crust deforms dominantly along the plate margins. Intraplate deformation differs from that respect by the observation that deformation can occur anywhere the crust is weak and not just at plate margins. Deformation is the folding, breaking, or flow of rocks. There are many different types of crustal deformation depending on whether the rocks are brittle or Ductility, ductile. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Asia Topographic Map
East is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sunrise, Sun rises on the Earth. Etymology As in other languages, the word is formed from the fact that east is the direction where the Sun rises: ''east'' comes from Middle English ''est'', from Old English ''ēast'', which itself comes from the Proto-Germanic language, Proto-Germanic *''aus-to-'' or *''austra-'' "east, toward the sunrise", from Proto-Indo-European language, Proto-Indo-European *aus- "to shine," or "dawn", cognate with Old High German ''*ōstar'' "to the east", Latin ''aurora'' 'dawn', and Greek language, Greek ''ēōs'' 'dawn, east'. Examples of the same formation in other languages include Latin Orient, oriens 'east, sunrise' from orior 'to rise, to originate', Greek language, Greek ανατολή Anatolia, anatolé 'east' from ἀνατέλλω 'to rise' and Hebrew מִזְרָח mizraḥ 'east' from זָרַח zara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic Era
The Cenozoic Era ( ; ) is Earth's current geological Era (geology), era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, Insect, insects, birds and flowering plant, angiosperms (flowering plants). It is the latest of three geological eras of the Phanerozoic Eon (geology), Eon, preceded by the Mesozoic and Paleozoic. The Cenozoic started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the Northern Hemisphere and the metatherians (marsupials, now mainly restricted to Australia and to some extent South America) in the Southern Hemisphere. The extinction of many groups allowed mamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Crustal Flow
In geodynamics lower crustal flow is the mainly lateral movement of material within the lower part of the continental crust by a ductile flow mechanism. It is thought to be an important process during both continental collision and continental break-up. Rheology The tendency of the lower crust to flow is controlled by its rheology. Ductile flow in the lower crust is assumed to be controlled by the deformation of quartz and/or plagioclase feldspar as its composition is thought to be granodioritic to dioritic. With normal thickness continental crust and a normal geothermal gradient, the lower crust, below the brittle–ductile transition zone, exhibits ductile flow behaviour under geological strain rates. Factors that can vary this behaviour include: water content, thickness, heat flow and strain-rate. Collisional belts In some areas of continental collision, the lower part of the thickened crust that results is interpreted to flow laterally, such as in the Tibetan plateau, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraplate Earthquake
An intraplate earthquake occurs in the ''interior'' of a Plate tectonics, tectonic plate, in contrast to an interplate earthquake on the ''boundary'' of a tectonic plate. They are relatively rare compared to the more familiar interplate earthquakes. Buildings far from plate boundaries are rarely protected with seismic retrofitting, so large intraplate earthquakes can inflict heavy damage. Examples of damaging intraplate earthquakes are the devastating 2001 Gujarat earthquake, the 2011 Christchurch earthquake, the 2012 Indian Ocean earthquakes, the 2017 Puebla earthquake, the 1811–1812 New Madrid earthquakes, and the 1886 Charleston earthquake. An earthquake that occurs within a subducting plate is known as an intraslab earthquake. Description The Earth's Crust (geology), crust is made up of seven primary and eight secondary Plate tectonics, tectonic plates, plus dozens of tertiary microplates. The large plates move very slowly on top of convection currents in the underlying Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alice Springs Orogeny
The Alice Springs Orogeny was a major intraplate tectonic (mountain building) episode in central Australia responsible for the formation of a series of large mountain ranges. The deformation associated with the Alice Spring Orogeny caused the vertically-tilted sandstone layers of the iconic Uluru/Ayers Rock. Duration The Alice Springs Orogeny was a long lived event, beginning approximately 450 million years ago and concluding about 300 million years ago,Bradshaw JD, Evans PR (1988). "Palaeozoic tectonics, Amadeus Basin, central Australia". The APEA Journal 28: 267–282 and it involved less than 100 km of distributed shortening. Extent The Alice Springs orogeny was centred in an area that had previously been a marine sedimentary basin, and involved the thrusting up of the underlying metamorphic and igneous rocks of Proterozoic age. The Alice Springs Orogeny had its beginnings in the Late Ordovician, continuing during the Silurian and Devonian, and by the Carboniferous t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tian Shan Mountains
The Tian Shan, also known as the Tengri Tagh or Tengir-Too, meaning the "Mountains of God/Heaven", is a large system of mountain ranges in Central Asia. The highest peak is Jengish Chokusu at high and located in Kyrgyzstan. Its lowest point is at the Turpan Depression, which is below sea level. The Tian Shan is sacred in Tengrism. Its second-highest peak is known as Khan Tengri, which can be translated as "Lord of the Spirits". At the 2013 Conference on World Heritage, the eastern portion of Tian Shan in western China's Xinjiang Region was listed as a World Heritage Site. The western portion in Kyrgyzstan, Kazakhstan, and Uzbekistan was then listed in 2016. Geography Tian Shan with the ancient Silk Road The Tian Shan range is located north and west of the Taklamakan Desert and directly north of the Tarim Basin. It straddles the border regions of Kazakhstan, Kyrgyzstan, Uzbekistan and Xinjiang in Northwest China. To the south, it connects with the Pamir Mountains, while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mongolia
Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by population density, most sparsely populated sovereign state. Mongolia is the world's largest landlocked country that does not border an Endorheic basin, inland sea, and much of its area is covered by grassy steppe, with mountains to the north and west and the Gobi Desert to the south. Ulaanbaatar, the capital and List of cities in Mongolia, largest city, is home to roughly half of the country's population. The territory of modern-day Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the First Turkic Khaganate, the Second Turkic Khaganate, the Uyghur Khaganate and others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest List of largest empires, contiguous land empire i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrusion
Extrusion is a process used to create objects of a fixed cross section (geometry), cross-sectional profile by pushing material through a Die (manufacturing), die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex cross-sections; and to work materials that are brittle, because the material encounters only compressive stress, compressive and shear stress, shear stresses. It also creates excellent surface finish and gives considerable freedom of form in the design process. Drawing (manufacturing), Drawing is a similar process, using the tensile strength of the material to pull it through the die. It limits the amount of change that can be performed in one step, so it is limited to simpler shapes, and multiple stages are usually needed. Drawing is the main way to produce wire. Metal Bar stock, bars and tube (fluid conveyance), tubes are also often drawn. Extrusion may be continuous (theoretically producin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leigh Royden
Leigh "Wiki" Handy Royden (born October 15, 1955) is an American geologist. Early life Royden was born on October 15, 1955, in Palo Alto, California. Royden's father was Halsey Royden, a mathematician. Education Royden received an A.B. degree in physics from Harvard University and a PhD in geology and geophysics from the Massachusetts Institute of Technology (MIT). Career Royden became a member of the faculty at MIT in 1988. She is director of MIT's Experimental Study Group. Royden has published on thermal subsidence at the northeastern continental margin of North America and on retreating subduction boundaries formed during the collision of continental tectonic plates. In 1990, she was awarded the Donath Medal (Young Scientist Award) by the Geological Society of America. Royden was named a fellow of the American Geophysical Union in 2004. In 2011, she received the George P. Woollard Award. In 2013, she was awarded the Stephan Mueller Medal by the European Geosciences ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crust (geology)
In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be defined based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Mercury, Venus, Mars, Io, the Moon and other planetary bodies formed via igneous processes and were later modified by erosion, impact cratering, volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two types have different chemical compositions and physical properties and were formed by different geological processes. Types of crust Planetary geologists divide crust into three categories based on how and when it formed. Primary crust / primordial crust This is a planet's "original" crust. It forms from solidification of a magma ocean. Toward the end o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibet
Tibet (; ''Böd''; ), or Greater Tibet, is a region in the western part of East Asia, covering much of the Tibetan Plateau and spanning about . It is the homeland of the Tibetan people. Also resident on the plateau are other ethnic groups such as Mongols, Monpa people, Monpa, Tamang people, Tamang, Qiang people, Qiang, Sherpa people, Sherpa, Lhoba people, Lhoba, and since the 20th century Han Chinese and Hui people, Hui. Tibet is the highest region on Earth, with an average elevation of . Located in the Himalayas, the highest elevation in Tibet is Mount Everest, Earth's highest mountain, rising above sea level. The Tibetan Empire emerged in the 7th century. At its height in the 9th century, the Tibetan Empire extended far beyond the Tibetan Plateau, from the Tarim Basin and Pamirs in the west, to Yunnan and Bengal in the southeast. It then divided into a variety of territories. The bulk of western and central Tibet (Ü-Tsang) was often at least nominally unified under a ser ... [...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 and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time scales of up to thousands of years or more. The crust and 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 lithospheric mantle (or mantle lithosphere), the uppermost part of the mantle that is not convecting. The layer below the lithosphere is called the asthenosphere, which is the weaker, hotter, and deeper part of the upper mantle that is able to convect. 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 f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
