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Cochetopa Dome
Cochetopa Dome is a mountain in the San Juan Mountains, in Saguache County, Colorado. The mountain is located in the Gunnison National Forest. With a prominence of , Cochetopa Dome is the 110th most prominent summit in the state of Colorado. Geology Cochetopa Dome is a rhyolitic lava dome, extruded into the Cochetopa caldera approximately 27 million years ago. The Chochetopa caldera is one of over a dozen such collapsed volcanoes within the San Juan volcanic field. The caldera is approximately wide and vertical subsidence was up to . The Cochetopa caldera, with Cochetopa Dome within it, is one of the most recognizable of the calderas in the region. Helping preserve the structure of this particular caldera is that its development was more recent than many of the larger calderas elsewhere in the San Juan Mountains, thus there was less regional volcanism to disrupt the caldera's structure. Also, the caldera was only modestly filled with post-subsidence sediments and much of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Level Datum Of 1929
The National Geodetic Vertical Datum of 1929 is the official name since 1973 of the vertical datum established for vertical control surveying in the United States, United States of America by the General Adjustment of 1929. Originally known as Sea Level Datum of 1929, NGVD 29 was determined and published by the National Geodetic Survey and used to measure the elevation of a point above and depression (geology), depression below mean sea level (MSL). NGVD29 was superseded by the North American Vertical Datum of 1988 (NAVD 88), based upon reference to a single benchmark (referenced to the new International Great Lakes Datum of 1985 local mean sea level height value), although many cities and U.S. Army Corps of Engineers "legacy" projects with established data continued to use the older datum. Methodology Mean sea level was measured at 26 tide gauges: 21 in the United States and 5 in Canada. The datum was defined by the observed heights of mean sea level at the 26 tide gauges and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, ''tuffaceous sandstone''). Tuff composed of sandy volcanic material can be referred to as volcanic sandstone. Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the ''moai'' statues on Easter Island. Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms. Tuff is often erroneously called tufa in guidebooks and in television programmes. Volcanic ash The material that is expelled in a volcanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountains Of Colorado
This list includes significant mountain peaks and high points located in the United States arranged alphabetically by state, district, or territory. The highest peak or point in each state, district or territory is noted in bold. Significant mountain peaks and high points Alabama *Brindley Mountain * Cheaha Mountain, highest summit in the State of Alabama *Monte Sano Mountain * Capshaw Mountain * Dirtseller Mountain * Frog Mountain *Hawk Pride Mountain * Gunters Mountain *Sand Mountain (Alabama) * Keel Mountain (Alabama) *Halama Mountain Alaska * Afognak Mountain, summit of Afognak Island * Amak Volcano, active stratovolcano * Amherst Peak * Amulet Peak * Andy Simons Mountain * Annex Peak * Anvil Peak , active stratovolcano that forms the summit of Semisopochnoi Island * Arthur Peak * Asses Ears (Alaska) * Atna Peaks * Atuk Mountain , summit of St. Lawrence Island * Augustine Volcano, active lava dome that forms the summit of Augustine Island * Auke Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountains Of Saguache County, Colorado
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (1,000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Juan Mountains (Colorado)
The San Juan Mountains is a high and rugged mountain range in the Rocky Mountains in southwestern Colorado and northwestern New Mexico. The area is highly mineralized (the Colorado Mineral Belt) and figured in the gold and silver mining industry of early Colorado. Major towns, all old mining camps, include Creede, Lake City, Silverton, Ouray, and Telluride. Large scale mining has ended in the region, although independent prospectors still work claims throughout the range. The last large scale mines were the Sunnyside Mine near Silverton, which operated until late in the 20th century and the Idarado Mine on Red Mountain Pass that closed down in the 1970s. Famous old San Juan mines include the Camp Bird and Smuggler Union mines, both located between Telluride and Ouray. The Summitville mine was the scene of a major environmental disaster in the 1990s when the liner of a cyanide-laced tailing pond began leaking heavily. Summitville is in the Summitville caldera, one of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Colorado County High Points
This is a list of all 64 counties of the U.S. State of Colorado by their points of highest elevation. Of the 50 highest county high points in the United States, 30 are located in Colorado. The highest point in Colorado is the summit of Mount Elbert in Lake County, the highest summit the entire Rocky Mountains at elevation. Of the 64 Colorado counties, 20 counties rise above elevation, 32 counties rise above , 42 counties rise above , and all 64 Colorado counties rise above . Use the "Map this section's coordinates" link to view the location of each of the Colorado county high points. __TOC__ Colorado county high points Gallery Mt._Elbert.jpg, 1. Mount Elbert in Lake County Mount_Harvard_(Colorado)_-_2006-07-16.jpg, 2. Mount Harvard in Chaffee County MtBlancaEast.jpg, 3. Mount Blanca straddling Alamosa and Costilla counties Uncompahgre_peak.jpg, 6. Uncompahgre Peak in Hinsdale County Crestone_peak_2.jpg, 7. Crestone Peak in Saguache County Mount_Lincoln_Colorad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of The Most Prominent Summits Of Colorado
The following sortable table comprises the 100 Topographic prominence, most topographically prominent Summit, mountain peaks of the United States, U.S. Colorado, State of Colorado. Elevation, Topographic elevation is the vertical distance above the reference geoid, a mathematical model of the Earth's sea level as an equipotential Gravity, gravitational surface. The topographic prominence of a summit is the elevation difference between that summit and the highest or key col to a higher summit. The topographic isolation of a summit is the minimum great-circle distance to a point of equal elevation. This article defines a significant summit as a summit with at least of topographic prominence, and a major summit as a summit with at least of topographic prominence. An Ultra-prominent peak, ultra-prominent summit is a summit with at least of topographic prominence. There are List of the ultra-prominent summits of the United States, 126 ultra-prominent summits in the United Sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Mountains Of The United States
This list includes significant mountain peaks and high points located in the United States arranged alphabetically by state, district, or territory. The highest peak or point in each state, district or territory is noted in bold. Significant mountain peaks and high points Alabama *Brindley Mountain * Cheaha Mountain, highest summit in the State of Alabama *Monte Sano Mountain * Capshaw Mountain * Dirtseller Mountain * Frog Mountain *Hawk Pride Mountain * Gunters Mountain *Sand Mountain (Alabama) * Keel Mountain (Alabama) *Halama Mountain Alaska * Afognak Mountain, summit of Afognak Island * Amak Volcano, active stratovolcano * Amherst Peak * Amulet Peak * Andy Simons Mountain * Annex Peak * Anvil Peak , active stratovolcano that forms the summit of Semisopochnoi Island * Arthur Peak * Asses Ears (Alaska) * Atna Peaks * Atuk Mountain , summit of St. Lawrence Island * Augustine Volcano, active lava dome that forms the summit of Augustine Island * Auke Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Mountain Ranges Of Colorado
This is a list of the major mountain ranges in the U.S. State of Colorado. All of these ranges are considered subranges of the Southern Rocky Mountains. As given in the table, topographic elevation is the vertical distance above the reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface. The topographic prominence of a summit is the elevation difference between that summit and the highest or key col to a higher summit. The topographic isolation of a summit is the minimum great-circle distance to a point of equal elevation. All elevations in this article include an elevation adjustment from the National Geodetic Vertical Datum of 1929 (NGVD 29) to the North American Vertical Datum of 1988 (NAVD 88). For further information, please see this United States National Geodetic Surveybr>note If an elevation or prominence is calculated as a range of values, the arithmetic mean is shown. __TOC__ Mountain ranges Gallery Image:Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yosemite Decimal System
The Yosemite Decimal System (YDS) is a three-part system used for rating the difficulty of walks, hikes, and climbs, primarily used by mountaineers in the United States and Canada. It was first devised by members of the Sierra Club in Southern California in the 1950s as a refinement of earlier systems, particularly those developed in Yosemite Valley, and quickly spread throughout North America. Description The class 5 portion of the class scale is primarily a rock climbing classification system, while classes 1–2 are used mainly in hiking and trail running. Class 3 describes easy and moderate climbing (i.e. scrambling), with varying amounts of exposure (length of a possible fall). Class 4 is an "in-between" rating that describes a very exposed scramble, corresponding roughly to the IFAS classification of PD+. Climbers, specifically those involved with technical class 5 climbing, often abbreviate "class 3" and "class 4" to "3rd" and "4th" respectively. Originally the system was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from Partial melting, partial melts of existing rocks in either a Terrestrial planet, planet's mantle (geology), mantle or crust (geology), crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive (geology), extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form Volcanic glass, natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pêž’, 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] |
