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Geology Of Tennessee
The geology of Tennessee is as diverse as its landscapes. Politically, Tennessee is broken up into three Grand Divisions: East, Middle, and West Tennessee. Physically, Tennessee is also separated into three main types of landforms: river valley plain, highlands and basins, and mountains. The Paleozoic Most of the sediment across Middle Tennessee was deposited from the Ordovician to the Mississippian, roughly between 400 and 300 million years ago. The sediment was primarily deep ocean limestones with some shale layers. Mississippian limestones are generally thicker than those of the Ordovician, and additionally, more cherty. In the Ordovician, the Appalachian Mountains began to form and by the end of the Paleozoic were tall peaks. During the Pennsylvanian, the Cumberland Plateau formed along the edge of the Appalachians as beach and shore sediments, primarily sandstone today. The Mesozoic Most Mesozoic sediments were deposited in West Tennessee, along the present course of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennessee
Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to the north, Virginia to the northeast, North Carolina to the east, Georgia, Alabama, and Mississippi to the south, Arkansas to the southwest, and Missouri to the northwest. Tennessee is geographically, culturally, and legally divided into three Grand Divisions of East, Middle, and West Tennessee. Nashville is the state's capital and largest city, and anchors its largest metropolitan area. Other major cities include Memphis, Knoxville, Chattanooga, and Clarksville. Tennessee's population as of the 2020 United States census is approximately 6.9 million. Tennessee is rooted in the Watauga Association, a 1772 frontier pact generally regarded as the first constitutional government west of the Appalachian Mountains. Its name derives from "Tanas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Tennessee
East Tennessee is one of the three Grand Divisions of Tennessee defined in state law. Geographically and socioculturally distinct, it comprises approximately the eastern third of the U.S. state of Tennessee. East Tennessee consists of 33 counties, 30 located within the Eastern Time Zone and three counties in the Central Time Zone, namely Bledsoe, Cumberland, and Marion. East Tennessee is entirely located within the Appalachian Mountains, although the landforms range from densely forested mountains to broad river valleys. The region contains the major cities of Knoxville and Chattanooga, Tennessee's third and fourth largest cities, respectively, and the Tri-Cities, the state's sixth largest population center. During the American Civil War, many East Tennesseans remained loyal to the Union even as the state seceded and joined the Confederacy. Early in the war, Unionist delegates unsuccessfully attempted to split East Tennessee into a separate state that would remain as part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Tennessee
Middle Tennessee is one of the three Grand Divisions of the U.S. state of Tennessee that composes roughly the central portion of the state. It is delineated according to state law as 41 of the state's 95 counties. Middle Tennessee contains the state's capital and largest city, Nashville, as well as Clarksville, the state's fifth largest city, and Murfreesboro, the state's sixth largest city and largest suburb of Nashville. The Nashville metropolitan area, located entirely within the region, is the most populous metropolitan area in the state, and the Clarksville metropolitan area is the state's sixth most populous. Middle Tennessee is both the largest, in terms of land area, and the most populous of the state's three Grand Divisions. Geographically, Middle Tennessee is composed of the Highland Rim, which completely surrounds the Nashville Basin. The Cumberland Plateau is located in the eastern part of the region. Culturally, Middle Tennessee is considered part of the Upland Sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Tennessee
West Tennessee is one of the three Grand Divisions (Tennessee), Grand Divisions of the U.S. state of Tennessee that roughly comprises the western quarter of the state. The region includes 21 counties between the Tennessee River, Tennessee and Mississippi River, Mississippi rivers, delineated by state law. Its geography consists primarily of flat lands with rich soil and vast floodplain areas of the Mississippi River. Of the three regions, West Tennessee is the most sharply defined geographically, and is the lowest-lying. It is both the least populous and smallest, in land area, of the three Grand Divisions. Its largest city is Memphis, Tennessee, Memphis, the state's second most populous city. West Tennessee was originally inhabited by the Chickasaw, and was the last of the three Grand Divisions to be settled by Europeans. The region officially became part of the United States with the Jackson Purchase (U.S. historical region), Jackson Purchase in 1818, 22 years after Tennessee's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumberland River
The Cumberland River is a major waterway of the Southern United States. The U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 8, 2011 river drains almost of southern Kentucky and north-central Tennessee. The river flows generally west from a source in the Appalachian Mountains to its confluence with the Ohio River near Paducah, Kentucky, and the mouth of the Tennessee River. Major tributaries include the Obey, Caney Fork, Stones, and Red rivers. Although the Cumberland River basin is predominantly rural, there are also some large cities on the river, including Nashville and Clarksville, both in Tennessee. Also, the river system has been extensively altered for flood control. Major dams impound areas of both the main stem and many of its important tributaries. Geography Its headwaters are three separate forks that begin in Kentucky and converge in Baxter, KY, located in Harlan County. Martin's Fork starts n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD near Pomp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, are among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Most were hunter-ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mantle Plume
A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hotspots, such as Hawaii or Iceland, and large igneous provinces such as the Deccan and Siberian Traps. Some such volcanic regions lie far from tectonic plate boundaries, while others represent unusually large-volume volcanism near plate boundaries. Concepts Mantle plumes were first proposed by J. Tuzo Wilson in 1963 and further developed by W. Jason Morgan in 1971 and 1972. A mantle plume is posited to exist where super-heated material forms ( nucleates) at the core-mantle boundary and rises through the Earth's mantle. Rather than a continuous stream, plumes should be viewed as a series of hot bubbles of material. Reaching the brittle upper Earth's crust they form diapirs. These diapirs are "hotspots" in the crust. In particular, the conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nashville Basin
The Nashville Basin, also known as the Central Basin, is a term often used to describe the area surrounding Murfreesboro, Tennessee, in which Nashville is located. The Central Basin was caused by an uplifting which produced a dome known as the Nashville Dome. The Nashville Dome is evidenced by the underlying rock strata that all dip downwards away from Nashville. The uplifting of the Nashville Dome fractured overlying strata, making it more easily eroded and thus the "dome" resulted in a "basin". Uplifted strata in the center of a geological dome have higher potential erosive energy than the surrounding strata, because they are physically higher. Erosion thus acts on the uplifted area at a greater rate than on the surrounding flat-lying area, creating a low area, i.e. a basin. This area is more correctly referred to as the "Central Dome" of Tennessee. Nashville is located in the northwestern portion of the Central Basin. The basin extends for approximately forty-five to sixty m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dome (geology)
A dome is a feature in structural geology consisting of symmetrical anticlines that intersect each other at their respective apices. Intact, domes are distinct, rounded, spherical-to- ellipsoidal-shaped protrusions on the Earth's surface. However, a transect parallel to Earth's surface of a dome features concentric rings of strata. Consequently, if the top of a dome has been eroded flat, the resulting structure in plan view appears as a bullseye, with the youngest rock layers at the outside, and each ring growing progressively older moving inwards. These strata would have been horizontal at the time of deposition, then later deformed by the uplift associated with dome formation. Formation mechanisms There are many possible mechanisms responsible for the formation of domes, the foremost of which are post-impact uplift, refolding, and diapirism. Post-impact uplift A complex crater, caused by collision of a hypervelocity body with another larger than itself, is typified by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
