|
Sentinel Peak (Arizona)
Sentinel Peak is a peak in the Tucson Mountains southwest of downtown Tucson, Arizona, United States. The valley's first inhabitants grew crops at the mountain's base, along the Santa Cruz River. The name "Tucson" is derived from the O'odham ' (), meaning " t thebase of the black ill. In the 1910s, University of Arizona students used local basalt rock to construct a tall block "A" on the mountain's east face, near its summit, giving the peak its other name, "A" Mountain. The peak is part of a 272-acre (110 hectares) park, the largest natural resource park in the City of Tucson. Early history The fertile land at the base of Sentinel Peak was used for agriculture from until the 1930s. Bedrock mortars found on the sides of the peak are believed to have been used to grind corn and mesquite beans into flour. In the 1690s, the O'odham people living in the area were visited by Eusebio Francisco Kino, who established the nearby Mission San Xavier del Bac. After Presidio San ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tucson, Arizona
, "(at the) base of the black ill , nicknames = "The Old Pueblo", "Optics Valley", "America's biggest small town" , image_map = , mapsize = 260px , map_caption = Interactive map outlining Tucson , image_map1 = File:Pima County Incorporated and Unincorporated areas Tucson highlighted.svg , mapsize1 = 250px , map_caption1 = Location within Pima County , pushpin_label = Tucson , pushpin_map = USA Arizona#USA , pushpin_map_caption = Location within Arizona##Location within the United States , subdivision_type = Country , subdivision_type1 = State , subdivision_type2 = County , subdivision_name = United States , subdivision_name1 = Arizona , subdivision_name2 = Pima , established_title = Founded , established_date = August 20, 1775 , established_title1 = Incorporated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectoni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomona College
Pomona College ( ) is a private liberal arts college in Claremont, California. It was established in 1887 by a group of Congregationalists who wanted to recreate a "college of the New England type" in Southern California. In 1925, it became the founding member of the Claremont Colleges consortium of adjacent, affiliated institutions. Pomona is a four-year undergraduate institution that approximately students. It offers 48 majors in liberal arts disciplines and roughly 650 courses, as well as access to more than 2,000 additional courses at the other Claremont Colleges. Its campus is in a residential community east of downtown Los Angeles, near the foothills of the San Gabriel Mountains. Pomona has the lowest acceptance rate of any U.S. liberal arts college and is considered the most prestigious liberal arts college in the American West and one of the most prestigious in the country. It has a $ endowment , making it the seventh-wealthiest college or university in the U.S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona Wildcats Football
The Arizona Wildcats football program represents the University of Arizona (UA) in the sport of American college football. Arizona competes in the Football Bowl Subdivision (FBS) of the National Collegiate Athletic Association (NCAA) and the South Division of the Pac-12 Conference (Pac-12). They play their home games at Arizona Stadium, which opened in 1929 on the university's campus in Tucson, Arizona, and has a capacity of 50,782. The team is coached by Jedd Fisch. Arizona's inaugural season was in 1889. The school joined the Pac-10 Conference in 1978 alongside rival Arizona State, and became a member of the Pac-12 South Division when the conference realigned in 2011. The Wildcats have won six conference championships (including the 1993 Pac-10 title) and made 21 bowl appearances, one of which are among the New Year's Six Bowls. History Early history (1899–1979) The varsity football program at the University of Arizona began in 1899, though the Wildcats nickname was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apache Indians
The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño and Janero), Salinero, Plains (Kataka or Semat or "Kiowa-Apache") and Western Apache ( Aravaipa, Pinaleño, Coyotero, Tonto). Distant cousins of the Apache are the Navajo, with whom they share the Southern Athabaskan languages. There are Apache communities in Oklahoma and Texas, and reservations in Arizona and New Mexico. Apache people have moved throughout the United States and elsewhere, including urban centers. The Apache Nations are politically autonomous, speak several different languages, and have distinct cultures. Historically, the Apache homelands have consisted of high mountains, sheltered and watered valleys, deep canyons, deserts, and the southern Great Plains, including areas in what is now Eastern Arizona, Northern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona Daily Star
The ''Arizona Daily Star'' is the major morning daily newspaper that serves Tucson and surrounding districts of southern Arizona in the United States. History L. C. Hughes was the Arizona Territory governor and founder of the ''Arizona Star'', in 1877. The first issue was published on March 29, 1877. The newspaper became the ''Arizona Daily Star'' in June 1879. The paper was purchased by Pulitzer in 1971; Lee Enterprises bought Pulitzer in 2005. Awards In 1981, ''Star'' reporters Clark Hallas and Robert B. Lowe won the Pulitzer Prize for Local Investigative Specialized Reporting for their stories about recruiting violations by University of Arizona The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first ... football coach, Tony Mason. References External links * * ''Arizona D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lahars
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extremely destructive: they can flow tens of metres per second, they have been known to be up to deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the latter of which killed thousands of people in the town of Armero. Etymology The word ''lahar'' is of Javanese origin. Berend George Escher introduced it as a geological term in 1922. Description The word ''lahar'' is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and 60 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Bed
Lava fields are large, mostly flat areas of surface or subaquatic lava flows. Such features are generally composed of highly fluid basalt lava, and can extend for tens or hundreds of miles across the underlying terrain. Morphology and structure The final morphology of a lava field can reveal properties such as internal structure, composition, and mechanics of the lava flow when it was fluid. The ridges and patterns on top of the lava field show the direction of the channels and the oftentimes active lava tubes that may be underneath the solidified "crust." It can also reveal whether the lava flow can be classified as pāhoehoe or 'a'ā. The two main types of lava field structures are defined as sheet flow lava and pillow lava. Sheet flow lava appears like a wrinkled or folded sheet, while pillow lava is bulbous, and often looks like a pile of pillows atop one another. An important aspect of lava flow morphology is a phenomenon known as lava flow inflation. This occurs in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from conglomerate because the rock fragments have sharp edges that have not been worn down. These indicate that the gravel was deposited very close to its source area, since othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as ''tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal and hu ... [...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] |
Basaltic Andesite
Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central America and the Andes of South America. Description Basaltic andesite is a fine-grained (aphanitic) igneous rock that is moderately low in silica and low in alkali metal oxides. It is not separately defined in the QAPF classification, which is based on the relative percentages of quartz, alkali feldspar, plagioclase feldspar, and feldspathoids, but would fall in the basalt-andesite field. This corresponds to rock in which feldspathoid makes up less than 10% and quartz less than 20% of the total QAPF fraction, and in which at least 65% of the feldspar is plagioclase. Basaltic andesite would be further distinguished from basalt and andesite by a silica content between 52% and 57%. Although classification by mineral content is preferred ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
