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Joint (geology)
In geology, and more specifically in structural geology, a joint is a break (fracture (geology), fracture) of natural origin in a layer or body of Rock (geology), rock that lacks visible or measurable movement parallel to the surface (plane) of the fracture ("Mode 1" Fracture). Although joints can occur singly, they most frequently appear as joint sets and systems. A ''joint set'' is a family of parallel, evenly spaced joints that can be identified through mapping and analysis of their orientations, spacing, and physical properties. A ''joint system'' consists of two or more intersecting joint sets. The distinction between joints and Fault (geology), faults hinges on the terms ''visible'' or ''measurable,'' a difference that depends on the scale of observation. Faults differ from joints in that they exhibit visible or measurable lateral movement between the opposite surfaces of the fracture ("Mode 2" and "Mode 3" Fractures). Thus a joint may be created by either strict movement o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joints (Bar Harbor Formation, Silurian-Devonian; Bar Harbor, Mt
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw-Hill Connect. Webp.274/ref> They are constructed to allow for different degrees and types of movement. Some joints, such as the knee, elbow, and shoulder, are self-lubricating, almost frictionless, and are able to withstand compression and maintain heavy loads while still executing smooth and precise movements. Other joints such as suture (joint), sutures between the bones of the skull permit very little movement (only during birth) in order to protect the brain and the sense organs. The connection between a tooth and the jawbone is also called a joint, and is described as a fibrous joint known as a gomphosis. Joints are classified both structurally and functionally. Joints play a vital role in the human body, contributing to movement, sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensile Stress
In continuum mechanics, stress is a physical quantity that describes forces present during deformation. For example, an object being pulled apart, such as a stretched elastic band, is subject to ''tensile'' stress and may undergo elongation. An object being pushed together, such as a crumpled sponge, is subject to ''compressive'' stress and may undergo shortening. The greater the force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Stress has dimension of force per area, with SI units of newtons per square meter (N/m2) or pascal (Pa). Stress expresses the internal forces that neighbouring particles of a continuous material exert on each other, while ''strain'' is the measure of the relative deformation of the material. For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushes on the particles immediately below it. When a liquid is in a closed container under pressure, each pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the south. With an estimated population of 587,618 as of 2024, Wyoming is the List of U.S. states and territories by population, least populous state despite being the List of U.S. states and territories by area, 10th largest by area, and it has the List of U.S. states by population density, second-lowest population density after Alaska. The List of capitals in the United States, state capital and List of municipalities in Wyoming, most populous city is Cheyenne, Wyoming, Cheyenne, which had a population of 65,132 in 2020. Wyoming's western half consists mostly of the ranges and rangelands of the Rocky Mountains; its eastern half consists of high-elevation prairie, and is referred to as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devils Tower
Devils Tower (also known as Mato Tipila or Bear Lodge) is a butte, laccolithic, composed of igneous rock in the Bear Lodge Ranger District of the Black Hills, near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River. It rises above the Belle Fourche River, standing from summit to base. The summit is above sea level. Devils Tower National Monument was the first United States national monument, established on September 24, 1906, by President Theodore Roosevelt. The monument's boundary encloses an area of . Name Indigenous names for the monolith include "Bear's House" or "Bear's Lodge" (or "Bear's Tipi", "Home of the Bear", "Bear's Lair"); Cheyenne, , ("Home of Bears"), "Aloft on a Rock" (Kiowa), "Tree Rock", "Great Gray Horn", and "Brown Buffalo Horn" (). The name "Devil's Tower" originated in 1875 during an expedition led by Colonel Richard Irving Dodge, when his interpreter reportedly misinterpreted a native name to mean "Bad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madeira
Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of the Canary Islands, Spain, west of the Morocco and southwest of mainland Portugal. Madeira sits on the African Plate, African Tectonic Plate, but is culturally, politically and ethnically associated with Europe, with its population predominantly descended from Portuguese settlers. Its population was 251,060 in 2021. The capital of Madeira is Funchal, on the main island's south coast. The archipelago includes the islands of Madeira Island, Madeira, Porto Santo Island, Porto Santo, and the Desertas Islands, Desertas, administered together with the separate archipelago of the Savage Islands. Roughly half of the population lives in Funchal. The region has political and administrative autonomy through the Autonomous Regions of Portugal#Const ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porto Santo Island
Porto Santo Island () is a Portuguese island and municipality northeast of Madeira Island in the North Atlantic Ocean; it is the northernmost and easternmost island of the archipelago of Madeira, located in the Atlantic Ocean west of Europe and Africa. The municipality of Porto Santo occupies the entire island and small neighbouring islands. It was elevated to city status on 6 August 1996. The sole parish of the municipality is also named Porto Santo. The population in 2011 was 5,483, in an area of 42.59 km2. The main settlement on the island is Vila Baleira. History It appears that some knowledge of Atlantic islands, such as Madeira, existed before the discovery and settlement of these lands, as the islands appear on maps as early as 1339. From a portolan dating to 1351, and preserved in Florence, Italy, it would appear that the islands of Madeira had been discovered long before being claimed by the Portuguese expedition of 1418. In '' Libro del Conocimiento'' (1348� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Ireland
Northern Ireland ( ; ) is a Countries of the United Kingdom, part of the United Kingdom in the north-east of the island of Ireland. It has been #Descriptions, variously described as a country, province or region. Northern Ireland shares Republic of Ireland–United Kingdom border, an open border to the south and west with the Republic of Ireland. At the 2021 United Kingdom census, 2021 census, its population was 1,903,175, making up around 3% of the Demographics of the United Kingdom#Population, UK's population and 27% of the population on the island of Ireland#Demographics, Ireland. The Northern Ireland Assembly, established by the Northern Ireland Act 1998, holds responsibility for a range of Devolution, devolved policy matters, while other areas are reserved for the Government of the United Kingdom, UK Government. The government of Northern Ireland cooperates with the government of Ireland in several areas under the terms of the Good Friday Agreement. The Republic of Ireland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant's Causeway
The Giant's Causeway () is an area of approximately 40,000 interlocking basalt columns, the result of an ancient volcano, volcanic fissure eruption, part of the North Atlantic Igneous Province active in the region during the Paleogene period. It is located in County Antrim on the north coast of Northern Ireland, about northeast of the town of Bushmills, County Antrim, Bushmills. It was declared a World Heritage Site by UNESCO in 1986 and a national nature reserve (United Kingdom), national nature reserve by the Department of the Environment (Northern Ireland), Department of the Environment for Northern Ireland in 1987. In a 2005 poll of ''Radio Times'' readers, the Giant's Causeway was named the fourth-greatest Wonders of the World, natural wonder in the United Kingdom. The tops of the columns form stepping stones that lead from the cliff foot and disappear under the sea. Most of the columns are hexagonal, although some have four, five, seven, or eight sides. The tallest are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columnar Jointing
Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as Joint (geology), joints, result in the formation of a regular array of polygonal Prism (geometry), prisms, or columns. Columnar jointing occurs in many types of igneous rocks (e.g. basalt, andesite, rhyolite), and forms as the rock cools and contracts. Columnar jointing can occur in cooling lava flows and ashflow tuffs (ignimbrites), as well as in some shallow intrusions. Columnar jointing also occurs rarely in sedimentary rocks, due to a combination of Solution_(chemistry), dissolution and Precipitation_(chemistry), reprecipitation of interstitial minerals (often quartz or cryptocrystalline silica) by hot, hydrothermal fluids and the expansion and contraction of the rock unit, both resulting from the presence of a nearby Igneous intrusion, magmatic intrusion. The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pie Chart
A pie chart (or a circle chart) is a circular Statistical graphics, statistical graphic which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and area) is Proportionality (mathematics), proportional to the quantity it represents. While it is named for its resemblance to a pie which has been sliced, there are variations on the way it can be presented. The earliest known pie chart is generally credited to William Playfair's ''Statistical Breviary'' of 1801.Spence (2005)Tufte, p. 44 Pie charts are very widely used in the business world and the mass media.Cleveland, p. 262 However, they have been criticized,Wilkinson, p. 23. and many experts recommend avoiding them,Tufte, p. 178.van Belle, p. 160–162.Stephen Few"Save the Pies for Dessert" August 2007, Retrieved 2010-02-02Steve Fento"Pie Charts Are Bad"/ref> as research has shown it is more difficult to make simple comparisons such as the si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereonet
In mathematics, a stereographic projection is a perspective projection of the sphere, through a specific point on the sphere (the ''pole'' or ''center of projection''), onto a plane (the ''projection plane'') perpendicular to the diameter through the point. It is a smooth, bijective function from the entire sphere except the center of projection to the entire plane. It maps circles on the sphere to circles or lines on the plane, and is conformal, meaning that it preserves angles at which curves meet and thus locally approximately preserves shapes. It is neither isometric (distance preserving) nor equiareal (area preserving). The stereographic projection gives a way to represent a sphere by a plane. The metric induced by the inverse stereographic projection from the plane to the sphere defines a geodesic distance between points in the plane equal to the spherical distance between the spherical points they represent. A two-dimensional coordinate system on the stereo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
