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Valles Caldera National Preserve
Valles Caldera (or Jemez Caldera) is a wide volcanic caldera in the Jemez Mountains of northern New Mexico. Hot springs, streams, fumaroles, natural gas seeps and volcanic domes dot the caldera floor landscape. The highest point in the caldera is Redondo Peak, an resurgent lava dome located entirely within the caldera. Also within the caldera are several grass valleys, or ''valles'', the largest of which is Valle Grande ( ), the only one accessible by a paved road. In 1975, Valles Caldera was designated as a National Natural Landmark by the National Park Service with much of the caldera being within the Valles Caldera National Preserve, a unit of the National Park System. History Use of Valles Caldera dates back to the prehistoric times: spear points dating to 11,000 years ago have been discovered.Anscheutz, Kurt F. and Merlan, Thomas (2007)"More than a scenic mountain landscape: Valles Caldera National Preserve land use history" U.S. Department of Agriculture Rocky Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained ( aphanitic) in texture, but may be porphyritic, containing larger mineral crystals ( phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase. It is the extrusive equivalent to granite. Rhyolitic magma is extremely viscous, due to its high silica content. This favors explosive eruptions over effusive eruptions, so this type of magma is more often erupted as pyroclastic rock than as lava flows. Rhyolitic ash-flow tuffs are among the most voluminous of continental igneous rock formations. Rhyolitic tuff has been extensively used for construction. Obsidian, which is rhyolitic volcanic glass, has been used for tools from prehistoric times to the present day because it can be shaped to an extremely sharp edge. Rhyolitic pumice finds use as an abrasive, in concrete, and as a soil amendment. Description R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circulation through faults to hot rock deep in the Earth's crust. In either case, the ultimate source of the heat is radioactive decay of naturally occurring radioactive elements in the Earth's mantle, the layer beneath the crust. Hot spring water often contains large amounts of dissolved minerals. The chemistry of hot springs ranges from acid sulfate springs with a pH as low as 0.8, to alkaline chloride springs saturated with silica, to bicarbonate springs saturated with carbon dioxide and carbonate minerals. Some springs also contain abundant dissolved iron. The minerals brought to the surface in hot springs often feed communities of extremophiles, microorganisms adapted to extreme conditions, and it is possible that life on Earth ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Las Vegas, New Mexico
Las Vegas is a city in and the county seat of San Miguel County, New Mexico, United States. Once two separate municipalities (one a city and the other a town), both were named Las Vegas—West Las Vegas ("Old Town") and East Las Vegas ("New Town"); they are separated by the Gallinas River and retain distinct characters and separate, rival school districts. The population was 13,166 at the 2020 census. Las Vegas is located south of Raton, east of Santa Fe, northeast of Albuquerque, south of Colorado Springs, Colorado, and south of Denver. History Las Vegas was established in 1835 after a group of settlers received a land grant from the Mexican government. The town was laid out in the traditional Spanish Colonial style, with a central plaza surrounded by buildings which could serve as fortifications in case of attack. Las Vegas soon prospered as a stop on the Santa Fe Trail. During the Mexican–American War in 1846, Stephen W. Kearny delivered an address at the Plaz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treaty Of Guadalupe Hidalgo
The Treaty of Guadalupe Hidalgo ( es, Tratado de Guadalupe Hidalgo), officially the Treaty of Peace, Friendship, Limits, and Settlement between the United States of America and the United Mexican States, is the peace treaty that was signed on 2 February 1848, in the Villa de Guadalupe Hidalgo (now a neighborhood of Mexico City) between the United States and Mexico that ended the Mexican–American War (1846–1848). The treaty was ratified by the United States on 10 March and by Mexico on 19 May. The ratifications were exchanged on 30 May, and the treaty was proclaimed on 4 July 1848. With the defeat of its army and the fall of its capital in September 1847, Mexico entered into negotiations with the U.S. peace envoy, Nicholas Trist, to end the war. On the Mexican side, there were factions that did not concede defeat or seek to engage in negotiations. The treaty called for the United States to pay US$15 million to Mexico and to pay off the claims of American citizens against Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navajo People
The Navajo (; British English: Navaho; nv, Diné or ') are a Native American people of the Southwestern United States. With more than 399,494 enrolled tribal members , the Navajo Nation is the largest federally recognized tribe in the United States; additionally, the Navajo Nation has the largest reservation in the country. The reservation straddles the Four Corners region and covers more than 27,325 square miles (70,000 square km) of land in Arizona, Utah, and New Mexico. The Navajo Reservation is slightly larger than the state of West Virginia. The Navajo language is spoken throughout the region, and most Navajos also speak English. The states with the largest Navajo populations are Arizona (140,263) and New Mexico (108,306). More than three-fourths of the enrolled Navajo population resides in these two states. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obsidian
Obsidian () is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows. These flows have a high content of silica, granting them a high viscosity. The high viscosity inhibits diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava. Obsidian is hard, brittle, and amorphous; it therefore fractures with sharp edges. In the past, it was used to manufacture cutting and piercing tools, and it has been used experimentally as surgical scalpel blades. Origin and properties The '' Natural History'' by the Roman writer Pliny the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native Americans In The United States
Native Americans, also known as American Indians, First Americans, Indigenous Americans, and other terms, are the Indigenous peoples of the mainland United States (Indigenous peoples of Hawaii, Alaska and territories of the United States are generally known by other terms). There are 574 federally recognized tribes living within the US, about half of which are associated with Indian reservations. As defined by the United States Census, "Native Americans" are Indigenous tribes that are originally from the contiguous United States, along with Alaska Natives. Indigenous peoples of the United States who are not listed as American Indian or Alaska Native include Native Hawaiians, Samoan Americans, and the Chamorro people. The US Census groups these peoples as " Native Hawaiian and other Pacific Islanders". European colonization of the Americas, which began in 1492, resulted in a precipitous decline in Native American population because of new diseases, wars, ethnic cleansin ... [...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] |
Fort Collins
A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ("to make"). From very early history to modern times, defensive walls have often been necessary for cities to survive in an ever-changing world of invasion and conquest. Some settlements in the Indus Valley civilization were the first small cities to be fortified. In ancient Greece, large stone walls had been built in Mycenaean Greece, such as the ancient site of Mycenae (famous for the huge stone blocks of its ' cyclopean' walls). A Greek '' phrourion'' was a fortified collection of buildings used as a military garrison, and is the equivalent of the Roman castellum or English fortress. These constructions mainly served the purpose of a watch tower, to guard certain roads, passes, and borders. Though smaller than a real fortress, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Park System
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational properties with various title designations. The U.S. Congress created the agency on August 25, 1916, through the National Park Service Organic Act. It is headquartered in Washington, D.C., within the main headquarters of the Department of the Interior. The NPS employs approximately 20,000 people in 423 individual units covering over 85 million acres in all 50 states, the District of Columbia, and US territories. As of 2019, they had more than 279,000 volunteers. The agency is charged with a dual role of preserving the ecological and historical integrity of the places entrusted to its management while also making them available and accessible for public use and enjoyment. History Yellowstone National Park was created as the first nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grass Valley
A grass valley (also vega and valle) is a meadow located within a forested and relatively small drainage basin such as a headwater. Grass valleys are common in North America, where they are created and maintained principally by the work of beaver Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers ar ...s or browsers feeders. Rarely, they are associated with cienegas. The words vega and valle are loanwords from Spanish. Notable examples * Valles Caldera, New Mexico * Las Vegas Springs Preserve, Nevada See also * Rincon (meadow) Wetlands Fluvial landforms {{Topography-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on Earth are lava dome forming. The geochemistry of lava domes can vary from basalt (e.g. Semeru, 1946) to rhyolite (e.g. Chaiten, 2010) although the majority are of intermediate composition (such as Santiaguito, dacite-andesite, present day) The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite. Existence of lava domes has been suggested for some domed structures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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