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Placerville, Colorado
Placerville is a census-designated place (CDP) and post office in and governed by San Miguel County, Colorado, United States. The Placerville post office has the ZIP Code 81430 ( post office boxes). At the United States Census 2010, the population of the 81430 ZIP Code Tabulation Area was 727 including adjacent areas. History Placerville was originally established as a small mining camp, named after the placer gold mines located on the San Miguel River and Leopard Creek. The location became known as Old Placerville after the Rio Grande Southern Railroad constructed a depot and several passing sidings west of the original settlement, calling it Placerville. A. B. Frenzel discovered vanadium-bearing sandstone near Placerville in the late 1890s. The ore was in strataform bodies in the Entrada Sandstone (Jurassic) east of the town. The principal mineral was roscoelite, with minor montroseite and carnotite. By the fall of 1899, development was described as "of the most sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Census-designated Place
A census-designated place (CDP) is a Place (United States Census Bureau), concentration of population defined by the United States Census Bureau for statistical purposes only. CDPs have been used in each decennial census since 1980 as the counterparts of incorporated places, such as self-governing city (United States), cities, town (United States), towns, and village (United States), villages, for the purposes of gathering and correlating statistical data. CDPs are populated areas that generally include one officially designated but currently unincorporated area, unincorporated community, for which the CDP is named, plus surrounding inhabited countryside of varying dimensions and, occasionally, other, smaller unincorporated communities as well. CDPs include small rural communities, Edge city, edge cities, colonia (United States), colonias located along the Mexico–United States border, and unincorporated resort and retirement community, retirement communities and their environs. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post Office Box
A post office box (commonly abbreviated as P.O. box, or also known as a postal box) is a uniquely addressable lockable box located on the premises of a post office. In some regions, particularly in Africa, there is no door to door delivery of mail; for example, in Kenya. Consequently, renting a PO box has traditionally been the only way to receive mail in such countries. Generally, post office boxes are rented from the post office either by individuals or by businesses on a basis ranging from monthly to annual, and the cost of rent varies depending on the box size. Central business district (CBD) PO boxes are usually more expensive than rural PO boxes. In the United States, the rental rate used to be uniform across the country. Now, however, a postal facility can be in any of seven fee groups by location; in addition, certain customers qualify for free box rental, usually because the Postal Service does not offer carrier-route delivery to their physical addresses. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnotite
Carnotite is a potassium uranium vanadate radioactive mineral with chemical formula K2( U O2)2( VO4)2·3 H2O. The water content can vary and small amounts of calcium, barium, magnesium, iron, and sodium are often present. Occurrence Carnotite is a bright greenish-yellow mineral that occurs typically as crusts and flakes in sandstones. Amounts as low as one percent will color the sandstone a bright yellow. The high uranium content makes carnotite an important uranium ore. It is a secondary vanadium and uranium mineral usually found in sedimentary rocks in arid climates. In the United States it is an important ore of uranium in the Colorado Plateau region of the United States where it occurs as disseminations in sandstone and concentrations around petrified logs. It also occurs in the U.S. states of Wyoming, Colorado, South Dakota, Nevada, Arizona, and Utah. It also occurs incidentally in Grants, New Mexico, and Carbon County, Pennsylvania. Carnotite is reported in Congo (Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roscoelite
Roscoelite is a green mineral from the mica group that contains vanadium. The chemical formula is K( V3+, Al, Mg)2 Al Si3 O10(O H)2. Crystals of roscoelite take on the monoclinic form, and are from the 2/m point group. The appearance is semi transparent to translucent coloured olive brown to green brown. The lustre is pearly. The mineral shows pleochroism with X showing green-brown, and Y and Z axes showing olive-green colour. The mineral was named after Henry Enfield Roscoe who first produced vanadium metal. Chemical properties Roscoelite is a muscovite with aluminium substituted with vanadium. Vanadium can also be substituted by magnesium, iron, or manganese. Physical properties It is soft and the density is 2.93±0.01. The unit cell has dimensions :''a'' = 526 pm :''b'' = 909 pm :''c'' = 1025 pm, with an angle between axes of β=101.0°. The tetrahedral cation-oxygen atom distance is 164.1 pm, The distance from the cation to the oxygen in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entrada Sandstone
The Entrada Sandstone is a formation in the San Rafael Group found in the U.S. states of Wyoming, Colorado, northwest New Mexico, northeast Arizona, and southeast Utah. Part of the Colorado Plateau, this formation was deposited during the Jurassic Period sometime between 180 and 140 million years ago in various environments, including tidal mudflats, beaches, and sand dunes. The Middle Jurassic San Rafael Group was dominantly deposited as ergs (sand seas) in a desert environment around the shallow Sundance Sea. Description At its type section at Entrada Point, located in the northern part the San Rafael Swell in Emery County, Utah, the Entrada consists of red silty sandstone and lesser interbedded mudstone and is a slope-forming formation. This part of the Entrada is sometimes described as the "earthy facies". Here the Entrada is overlain by the Curtis Formation, and overlies the Carmel Formation.To the south and east, the Entrada transitions to cliff-forming red or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadium
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer ( passivation) somewhat stabilizes the free metal against further oxidation. Spanish scientist Andrés Manuel del Río discovered compounds of vanadium in 1801 in Mexico by analyzing a new lead-bearing mineral he called "brown lead". Though he initially presumed its qualities were due to the presence of a new element, he was later erroneously convinced by French chemist Hippolyte Victor Collet-Descotils that the element was just chromium. Then in 1830, Nils Gabriel Sefström generated chlorides of vanadium, thus proving there was a new element, and named it "vanadium" after the Scandinavian goddess of beauty and fertility, Vanadís (Freyja). The name was based on the wide range of colors found in vanadium compounds. Del Rio's lead mineral was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio Grande Southern Railroad
The Rio Grande Southern Railroad (reporting mark RGS, also referred to as "The Southern") was a 3 ft (914 mm) narrow-gauge railroad which ran in the southwestern region of the US state of Colorado, from the towns of Durango to Ridgway, routed via Lizard Head Pass. Built by Russian immigrant and Colorado toll road builder Otto Mears, the RGS operated from 1891 through 1951 and was built with the intent to transport immense amounts of silver mineral traffic that were being produced by the mining communities of Rico and Telluride. On both ends of the railroad, there were interchanges with The Denver and Rio Grande Railroad (reporting mark D&RG(W), later known as the Denver and Rio Grande Western), which would ship the traffic the RGS hauled elsewhere like the San Juan Smelter in Durango. For the first few years of its life, the RGS would have fallen under the definition of a "Bonanza Railroad" which meant it was an instant success, quickly generating more than enough m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leopard Creek
Leopard Creek is a stream located entirely within San Miguel County, Colorado. According to tradition, the sighting of a leopard near the creek accounts for the name. See also *List of rivers of Colorado This is a list of streams in the U.S. State of Colorado. __TOC__ Alphabetical list The following alphabetical list includes many important streams that flow through the State of Colorado, including all 158 named rivers. Where available, t ... References Rivers of San Miguel County, Colorado Rivers of Colorado {{Colorado-river-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Miguel River (Colorado)
The San Miguel River is a tributary of the Dolores River, approximately long, in southwestern Colorado in the United States. It rises in the San Juan Mountains southeast of Telluride and flows northwest, along the southern slope of the Uncompahgre Plateau, past the towns of Placerville and Nucla and joins the Dolores in western Montrose County approximately 15 miles (24 km) east of the state line with Utah. Geography and protected areas The San Miguel is more or less free-flowing; however, diversion dams dot the river and alter flows. In some parts it is however one of the few remaining naturally functioning rivers of the West. The San Miguel varies in gradient, from extremely steep in its upper reaches (forming a shallow, rocky, unnavigable stream) to more mellow in the lower sections ( of drop, which offers the whitewater boater a variety of runs all within the class II+--III range). All told, the San Miguel drops over from an alpine ecosystem to the desert. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium ( gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
