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Argillite
:''"Argillite" may also refer to Argillite, Kentucky.'' Argillite () is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts of silt-sized particles. The argillites grade into shale when the fissile layering typical of shale is developed. Another name for poorly lithified argillites is ''mudstone''. These rocks, although variable in composition, are typically high in aluminium and silica with variable alkali and alkaline earth cations. The term ''pelitic'' or ''pelite'' is often applied to these sediments and rocks. Metamorphism of argillites produces slate, phyllite, and pelitic schist. Belt Supergroup The Belt Supergroup, an assemblage of rocks of late Precambrian (Mesoproterozoic) age, includes thick sequences of argillite, as well as other metamorphosed or semi-metamorphosed mudstones.Schieber, J. 1990. Significance of styles of epicontinental shale sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belt Supergroup
The Belt Supergroup is an assemblage of primarily fine-grained sedimentary rocks and mafic intrusive rocks of late Precambrian (Mesoproterozoic) age. It is more than thick, covers an area of some 200,000 km2 (77,220 sq. mi), and is considered to be one of the world's best-exposed and most accessible sequences of Mesoproterozoic rocks. It was named after the Big Belt Mountains in west-central Montana. It is present in western Montana and northern Idaho, with minor occurrences in northeastern Washington and western Wyoming. It extends into Canada where the equivalent rocks, which are called the Purcell Supergroup, are exposed in southeastern British Columbia and southwestern Alberta. The rocks of the Belt Supergroup contain economically significant deposits of lead, zinc, silver, copper, gold, and other metals in a number of areas, and some of the Belt rocks contain fossil stromatolites. Spectacular outcrops of Belt rocks can be seen in Glacier National Park in northwestern Mont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbia, and Saskatchewan to the north. It is the fourth-largest state by area, the eighth-least populous state, and the third-least densely populated state. Its state capital is Helena. The western half of Montana contains numerous mountain ranges, while the eastern half is characterized by western prairie terrain and badlands, with smaller mountain ranges found throughout the state. Montana has no official nickname but several unofficial ones, most notably "Big Sky Country", "The Treasure State", "Land of the Shining Mountains", and " The Last Best Place". The economy is primarily based on agriculture, including ranching and cereal grain farming. Other significant economic resources include oil, gas, coal, mining, and lumber. The health ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argillite, Kentucky
Argillite is an unincorporated community on the Little Sandy River in Greenup County, Kentucky, United States. It sits at the southern end of the confluence of Kentucky Routes 1 and 207. The name refers to argillite, a type of stone, related to shale. Argillite was a stop along the Eastern Kentucky Railway The Eastern Kentucky Railway was a railroad in northeastern Kentucky, United States. It served mainly mine traffic, running north from Webbville through Grayson to Riverton (now part of Greenup) on the Ohio River and Chesapeake and Ohio Rail ... between the Simonton and Laurel stops. Argillite's ZIP Code is 41121. Notable person * Jeremy Bates, heavyweight boxer References Unincorporated communities in Greenup County, Kentucky Unincorporated communities in Kentucky {{GreenupCountyKY-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelite
A pelite (Greek: ''pelos'', "clay") or metapelite is a metamorphosed fine-grained sedimentary rock, i.e. mudstone or siltstone. The term was earlier used by geologists to describe a clay-rich, fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone, the metamorphosed version of which would technically have been a ''metapelite''. It was equivalent to the now little-used Latin-derived term lutite.Potter, P.E., J.B. Maynard, and P.J. Depetris (2005) ''Muds and Mudstones.'' New York, New York, Springer. 279 pp. Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. A semipelite is defined in part as having similar chemical composition but being of a crystalloblastic nature. Pettijohn (1975) gives the following descriptive terms based on grain size, avoiding the use of terms such as clay or argillaceous which carry an implication of chemical composition. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flathead Lake
Flathead Lake ( fla, člq̓etkʷ, label=Salish, kut, yawuʔnik̓ ʔa·kuq̓nuk) is a large natural lake in northwest Montana. The lake is a remnant of the ancient, massive glacial dammed lake, Lake Missoula of the era of the last interglacial. Flathead Lake is a natural lake along the mainline of the Flathead River. It was dammed in 1930 by Kerr Dam at its outlet on Polson Bay, slightly raising the lake level; the dam generates electricity.Kerr Dam PPL Montana The hydroelectric has been owned and operated by the Confederated Salish and Kootenai Tribes since 2015. It is one of the cleanest lakes in the populated world for its size and type. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Missoula, Montana
Missoula ( ; fla, label=Salish language, Séliš, Nłʔay, lit=Place of the Small Bull Trout, script=Latn; kut, Tuhuⱡnana, script=Latn) is a city in the U.S. state of Montana; it is the county seat of Missoula County, Montana, Missoula County. It is located along the Clark Fork River near its confluence with the Bitterroot River, Bitterroot and Blackfoot River (Montana), Blackfoot Rivers in western Montana and at the convergence of five mountain ranges, thus it is often described as the "hub of five valleys". The 2020 United States Census shows the city's population at 73,489 and the population of the Missoula Metropolitan Area at 117,922. After Billings, Montana, Billings, Missoula is the second-largest city and metropolitan area in Montana. Missoula is home to the University of Montana, a public research university. The Missoula area began seeing settlement by people of European descent in 1858 including William Thomas Hamilton (frontiersman), William T. Hamilton, who set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitterroot Mountains
The Northern and Central Bitterroot Range, collectively the Bitterroot Mountains (Salish: čkʷlkʷqin), is the largest portion of the Bitterroot Range, part of the Rocky Mountains and Idaho Batholith, located in the panhandle of Idaho and westernmost Montana in the northwestern United States. The mountains encompass an area of . The mountains are bordered on the north by Lolo Creek, to the northeast by the Clark Fork, on the south by the Salmon River, on the east by the Bitterroot River and Valley, and on the west by the Selway and Lochsa Rivers. Its highest summit is Trapper Peak, at . __TOC__ Northern Bitterroot Range The Northern Bitterroot Range is the northernmost and shortest subrange of the Bitterroot Mountains. The Northern Bitterroots encompass and its two tallest peaks are the Rhodes Peak and the Quartz Benchmark. The Northern Bitterroots also contain a smaller subrange, the Grave Creek Range. The Grave Creek Range is in area and its highest peak is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitterroot Valley
The Bitterroot Valley is located in southwestern Montana, along the Bitterroot River between the Bitterroot Range and Sapphire Mountains, in the Northwestern United States. Geography The valley extends approximately from Lost Trail Pass in Idaho, where it is narrow, to a point near the city of Missoula along Interstate 90 where it is wider and flatter. To the west is the Bitterroot Range and its large Selway-Bitterroot Wilderness Area, and to the east is the smaller Sapphire Mountains and their Anaconda-Pintler Wilderness Area. The Bitterroot Range has steep faces, deep canyons, is heavily forested, and is within the Bitterroot National Forest. The Sapphire Mountains are more rounded, drier, and much less forested. The southern end of the valley is split into the East and West Forks of the Bitterroot River, and the northern end has the confluence of the Bitterroot River with the Clark Fork River. Connecting into the west side of the valley are numerous deeply carved granit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoproterozoic
The Mesoproterozoic Era is a geologic era that occurred from . The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic), but little is known about them. The continental masses of the Mesoproterozoic were more or less the same ones that exist today, although their arrangement on the Earth's surface was different. Major events and characteristics The major events of this era are the breakup of the Columbia supercontinent, the formation of the Rodinia supercontinent, and the evolution of sexual reproduction. This era is marked by the further development of continental plates and plate tectonics. The supercontinent of Columbia broke up between 1500 and 1350 million years ago, and the fragments reassembled into the supercontinent of Rodinia around 1100 to 900 million years ago, on the time boundary between the Mesoproterozoic and the subsequent Neoproterozoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as micas, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schist''). Where the type of the original rock (the protolith) is discernible, the schist is us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllite
Phyllite ( ) is a type of foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation.Stephen Marshak ''Essentials of Geology'', 3rd ed. It is primarily composed of quartz, sericite mica, and chlorite. Phyllite has fine-grained mica flakes, whereas slate has extremely fine mica flakes, and schist has large mica flakes, all mica flakes of which have achieved a preferred orientation. Among foliated metamorphic rocks, it represents a gradation in the degree of metamorphism between slate and schist. The minute crystals of graphite, sericite, or chlorite, or the translucent fine-grained white mica, impart a silky, sometimes golden sheen to the surfaces of cleavage, called "phyllitic luster". The word comes from the Greek ''phyllon'', meaning "leaf". The protolith (or parent rock) for phyllite is shale or pelite, or slate, which in turn came from a shale protolith. Its constituent platy minerals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
