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Hopi Buttes
Hopi Buttes volcanic field is a monogenetic volcanic field located on the Colorado Plateau mostly on the Navajo Reservation around the town of Dilkon in northeastern Arizona north of Holbrook. The volcanic field covers an area of approximately and contains about 300 maars and diatremes. The erosional exposure of the deposits varies with those in the eastern portion exhibiting the shallowly eroded maar deposits and those in the western portion the more deeply eroded feeder diatremes. The maars result from explosive interaction of the hot diatreme material with the groundwater system and result in a mixture of volcanic tuff material and sediments of the Miocene–Pliocene lacustrine sediments of the Bidahochi Formation. In the western portion of the field the buttes consist of the feeder diatremes of monchiquite and nepheline syenite magmas. Most of the volcanic activity occurred between 8.5 and 6 million years ago, with the most recent dated at 4.2 million years ago. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monchiquite
Lamprophyres () are uncommon, small-volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks, and small intrusions. They are alkaline silica- undersaturated mafic or ultramafic rocks with high magnesium oxide, >3% potassium oxide, high sodium oxide, and high nickel and chromium. Lamprophyres occur throughout all geologic eras. Archaean examples are commonly associated with lode gold deposits. Cenozoic examples include magnesian rocks in Mexico and South America, and young ultramafic lamprophyres from Gympie in Australia with 18.5% MgO at ~250 Ma. Petrology Modern science treats lamprophyres as a catch-all term for ultrapotassic mafic igneous rocks which have primary mineralogy consisting of amphibole or biotite, and with feldspar in the groundmass. Lamprophyres are not amenable to classification according to modal proportions, such as the system QAPF, because of their peculiar mineralogy, nor compositional discrimination diagrams, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of The Navajo Nation
Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be. While geography is specific to Earth, many concepts can be applied more broadly to other celestial bodies in the field of planetary science. Geography has been called "a bridge between natural science and social science disciplines." Origins of many of the concepts in geography can be traced to Greek Eratosthenes of Cyrene, who may have coined the term "geographia" (). The first recorded use of the word γεωγραφία was as the title of a book by Greek scholar Claudius Ptolemy (100 – 170 AD). This work created the so-called "Ptolemaic tradition" of geography, which included "Ptolemaic cartographic theory." ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monogenetic Volcanic Fields
Monogenetic may refer to: * Monogenetic in biology, of or pertaining to monogenesis (Mendelian inheritance Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularize ...) * Monogenetic volcanic field in geology, a cluster of volcanoes that only erupted once * Monogenetic theory of pidgins in linguistics, a theory about the origin of creole languages See also * Monogenous (other) * Monogenic (other) * Monogenism (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landforms Of Apache County, Arizona
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, structure stratification, rock exposure, and soil type. Gross physical features or landforms include intuitive elements such as berms, cliffs, hills, mounds, peninsulas, ridges, rivers, valleys, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Fields Of Arizona
A volcano is commonly defined as a vent or fissure in the Crust (geology), crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where list of tectonic plates, tectonic plates are divergent boundary, diverging or convergent boundary, converging, and because most of Earth's plate boundaries are underwater, most volcanoes 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 resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanic Fields
A list of volcanic fields follows below. {{Incomplete list, date=May 2025 Africa Algeria * Atakor volcanic field * In Teria volcanic field * Manzaz volcanic field * Nemours-Nedroma * Tafna Beni Saf * Tahalra volcanic field Cameroon * Oku Volcanic Field Cape Verde * Charles Darwin volcanic field Chad * Tarso Toh Ethiopia * Dilo-Dukana volcanic field Eritrea *Assab volcanic field Kenya * Dilo-Dukana volcanic field Libya * Gharyan volcanic field * Haruj Madagascar * Ambre-Bobaomby volcanic field * Ankaizina volcanic field * Itasy volcanic field Morocco * Azrou volcanic field * Berguent volcanic field * Chott Tigri volcanic field * Mrit-Ment volcanic field * Oujda volcanic field * Oulmés volcanic field * Rekkame volcanic field Niger * Tin Taralle volcanic field * Todra volcanic field Sudan * Bayuda volcanic field * Meidob volcanic field * Tagabo Hills Asia China *Hainan Volcanic Field * Honggeertu volcanic field * Keluo * Northern Tibet volcanic field * Wudalianchi volcan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In The United States Of America
This article contains a list of volcanoes in the United States and its territories. Alaska American Samoa Arizona California Colorado Hawaii Idaho Illinois Louisiana Michigan Mississippi Missouri Nevada New Hampshire New Jersey New Mexico North Carolina Northern Mariana Islands Oregon Texas Utah Virginia Washington Wyoming See also *Geothermal energy in the United States *List of Cascade volcanoes * List of large volume volcanic eruptions in the Basin and Range Province *List of volcanoes in Canada *List of volcanoes in Mexico *List of volcanoes in Russia *List of volcanic craters in Alaska * List of volcanic craters in Arizona * List of lava flows in Arizona *List of Yellowstone geothermal features * National Volcano Early Warning and Monitoring System * United States Geological Survey National Volcanic Threat Assessment References External links 2018 Update to the U.S. Geological Survey Nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morale Claim Maar
Morale ( , ) is the capacity of a group's members to maintain belief in an institution or goal, particularly in the face of opposition or hardship. Morale is often referenced by authority figures as a generic value judgment of the willpower, obedience, and self-discipline of a group tasked with performing duties assigned by a superior. According to Alexander H. Leighton, "morale is the capacity of a group of people to pull together persistently and consistently in pursuit of a common purpose". With good morale, a force will be less likely to give up or surrender. Morale is usually assessed at a collective, rather than an individual level. In wartime, civilian morale is also important. Definition Military history experts have not agreed on a precise definition of "morale". Clausewitz's comments on the subject have been described as "deliberately vague" by modern scholars. George Francis Robert Henderson, a widely read military author of the pre-World War I era, viewed morale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographic Coordinates
A geographic coordinate system (GCS) is a spherical or geodetic coordinate system for measuring and communicating positions directly on Earth as latitude and longitude. It is the simplest, oldest, and most widely used type of the various spatial reference systems that are in use, and forms the basis for most others. Although latitude and longitude form a coordinate tuple like a cartesian coordinate system, the geographic coordinate system is not cartesian because the measurements are angles and are not on a planar surface. A full GCS specification, such as those listed in the EPSG and ISO 19111 standards, also includes a choice of geodetic datum (including an Earth ellipsoid), as different datums will yield different latitude and longitude values for the same location. History The invention of a geographic coordinate system is generally credited to Eratosthenes of Cyrene, who composed his now-lost ''Geography'' at the Library of Alexandria in the 3rd century ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
