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Compound Volcano
A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in the location of the principal vent area on a particular volcano. Stratovolcanoes can also form a large caldera that gets filled in by a lava dome, or else multiple small cinder cones, lava domes and craters may develop on the caldera's rim. Although a comparatively unusual type of volcano, they are widespread in the world and in geologic history. Metamorphosed ash flow tuffs are widespread in the Precambrian rocks of northern New Mexico, which indicates that caldera complexes have been important for much of Earth's history. Yellowstone National Park is on three partly covered caldera complexes. The Long Valley Caldera in eastern California is also a complex volcano; the San Juan Mountains in southwestern Colorado are formed on a gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homa Mountain
Homa may refer to: Places Ethiopia * Homa (woreda), a district in Oromia Region, Ethiopia Kenya * Homa Bay, a town and a bay on the shore of Lake Victoria in Kenya * Homa Mountain, a volcano near Homa Bay, Kenya Iran * Chal Homa, Markazi, Iran * Homa, Iran, a village in Lorestan Province, Iran * Homa, North Khorasan, Iran, a village * Homa-ye Bala (other), places in Iran * Homag (other), various places in Iran * Homay, Iran (other), various places in Iran Israel * Har Homa, East Jerusalem neighborhood, Israel United States * Homa Hills, Wyoming * La Homa, Texas, U.S. People People with the given name Homa * Homa Arjomand (born 1952), Iranian political activist * Homa Darabi (1994–1940), Iranian pediatrician, academic, and political activist * Homa Vafaie Farley, Iranian-born potter and ceramist * Homa Hoodfar, Canadian-Iranian sociocultural anthropologist * Homa Katouzian (born 1942), Iranian economist, historian, socio ... [...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 vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bennett Lake Caldera
The Bennett Lake Volcanic Complex (BLVC) is a huge 50-million-year-old extinct caldera complex that spans across the British Columbia-Yukon border in Canada. It is located near the western end of the West Arm of Bennett Lake. The caldera complex is surrounded by granitic rocks containing pendants. It is located near the eastern contact of the Coast Plutonic Complex and the Whitehorse Trough. There are thick series of pyroclastic and epiclastic rocks at the caldera. Remnants of this huge caldera complex are preserved near Bennett Lake in the Coast Mountains. The complex compose the Skukum Group. Formation and eruptive history The Bennett Lake Volcanic Complex was formed when the ancient Kula Plate was subducting under North America during the early Eocene period. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Idaho
Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyoming to the east, Nevada and Utah to the south, and Washington and Oregon to the west. The state's capital and largest city is Boise. With an area of , Idaho is the 14th largest state by land area, but with a population of approximately 1.8 million, it ranks as the 13th least populous and the 7th least densely populated of the 50 U.S. states. For thousands of years, and prior to European colonization, Idaho has been inhabited by native peoples. In the early 19th century, Idaho was considered part of the Oregon Country, an area of dispute between the U.S. and the British Empire. It officially became U.S. territory with the signing of the Oregon Treaty of 1846, but a separate Idaho Territory was not organized until 1863, instead be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, the 32nd-most populous, and the 9th-least densely populated of the U.S. states. Nearly three-quarters of Nevada's people live in Clark County, which contains the Las Vegas–Paradise metropolitan area, including three of the state's four largest incorporated cities. Nevada's capital is Carson City. Las Vegas is the largest city in the state. Nevada is officially known as the "Silver State" because of the importance of silver to its history and economy. It is also known as the "Battle Born State" because it achieved statehood during the Civil War (the words "Battle Born" also appear on its state flag); as the " Sagebrush State", for the native plant of the same name; and as the " Sage-hen State". The name means "snowy" in Spanish, re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configuration of continents. It is the latest of three geological eras since complex life evolved, preceded by the Mesozoic and Paleozoic. It started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the northern hemisphere and the metatherians (marsupials, now mainly restricted to Australia) in the southern hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of archosaurian reptiles, like the dinosaurs; an abundance of conifers and ferns; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic. The era began in the wake of the Permian–Triassic extinction event, the largest well-documented mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, pterosaurs, mosasaurs, and plesiosaurs. The Mesozoic was a time of significant tectonic, climatic, and evolutionary activity. The era witnessed the gradual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neogene
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans ('' Homo habilis'') appeared in Africa near the end of the period. Some continental movements took place, the most significant event being the connection of North America, North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is the List of U.S. states and territories by area, eighth most extensive and List of U.S. states and territories by population, 21st most populous U.S. state. The 2020 United States Census, 2020 United States census enumerated the population of Colorado at 5,773,714, an increase of 14.80% since the 2010 United States Census, 2010 United States census. The region has been inhabited by Indigenous peoples of the Americas, Native Americans and their Paleo-Indians, ancestors for at least 13,500 years and possibly much longer. The eastern edge of the Rocky Mountains was a major migration route for early peoples who spread throughout the Americas. "''Colorado''" is the Spanish adjective meaning "ruddy", th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Juan Mountains
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the most populated subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento is the state's capital, while Los Angeles is the most populous city in the state and the second most populous city in the country. San Francisco is the second most densely populated major city in the country. Los Angeles County is the country's most populous, while San Bernardino County is the largest county by area in the country. California borders Oregon to the north, Nevada and Arizona to the east, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Valley Caldera
Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about long (east-west), wide (north-south), and up to deep. Long Valley was formed 760,000 years ago when a very large eruption released hot ash that later cooled to form the Bishop tuff that is common to the area. The eruption emptied the magma chamber under the area to the point of collapse. The second phase of the eruption released pyroclastic flows that burned and buried thousands of square miles. Ash from this eruption blanketed much of the western part of what is now the United States. Geography The caldera is a giant bowl-shaped depression, approximately wide, surrounded by mountains except to the southeast. The elevation of the bottom of the bowl ranges from , being higher in the west. Near the center of the bowl, there is a resurgent dome formed by magmatic uplift. The southeastern slope from the caldera d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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