|
Alder Group
The Alder Group is a group of geologic formations exposed in the Mazatzal Mountains of central Arizona, US. It dates to the Statherian Period of the Paleoproterozoic and records mountain-building events associated with the assembly of North America. Description The formation consists of about of metavolcanic and metasedimentary rock exposed in the Mazatzal Mountains. The formation is underlain by the East Verde River Formation and overlain by the Red Rock Group. Together with the younger Mazatzal Group, these groups form the Tonto Basin Supergroup. The formation is mostly volcanic and volcaniclastic sedimentary rock, but with some sedimentary beds formed by weathering of continental rock (''terrigenous'' beds). All have experienced metamorphism. The Alder Group is interpreted as basin fill of an intra-arc basin that formed along what was then the southern coast of Laurentia Laurentia or the North American Craton is a large continental craton that forms the ancient ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Group
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoproterozoic
The Paleoproterozoic Era (;, also spelled Palaeoproterozoic), spanning the time period from (2.5–1.6 Ga), is the first of the three sub-divisions ( eras) of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's geological history. It was during this era that the continents first stabilized. Paleontological evidence suggests that the Earth's rotational rate ~1.8 billion years ago equated to 20-hour days, implying a total of ~450 days per year. Atmosphere Before the enormous increase in atmospheric oxygen, almost all existing lifeforms were anaerobic organisms whose metabolism was based on a form of cellular respiration that did not require oxygen. Free oxygen in large amounts is toxic to most anaerobic organisms. Consequently, most died when the atmospheric free oxygen levels soared in an extinction event called the Great Oxidation Event, which brought atmospheric oxygen levels to up to 10% of their current level. The only creatures that sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bug Group
Big or BIG may refer to: * Big, of great size or degree Film and television * ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks * ''Big!'', a Discovery Channel television show * ''Richard Hammond's Big'', a television show presented by Richard Hammond * ''Big'' (TV series), a 2012 South Korean TV series * ''Banana Island Ghost'', a 2017 fantasy action comedy film Music * '' Big: the musical'', a 1996 musical based on the film * Big Records, a record label * ''Big'' (album), a 2007 album by Macy Gray * "Big" (Dead Letter Circus song) * "Big" (Sneaky Sound System song) * "Big" (Rita Ora and Imanbek song) * "Big", a 1990 song by New Fast Automatic Daffodils * "Big", a 2021 song by Jade Eagleson from ''Honkytonk Revival'' *The Notorious B.I.G., an American rapper Places * Allen Army Airfield (IATA code), Alaska, US * BIG, a VOR navigational beacon at London Biggin Hill Airport * Big River (other), various rivers (and other things) * Big Island (disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jerome, Arizona
Jerome is a town in the Black Hills of Yavapai County in the U.S. state of Arizona. Founded in the late 19th century on Cleopatra Hill overlooking the Verde Valley, Jerome is located more than above sea level. It is about north of Phoenix along State Route 89A between Sedona and Prescott. Supported in its heyday by rich copper mines, it was home to more than 10,000 people in the 1920s. As of the 2010 census, its population was 444. It is now known for its tourist attractions, such as its "ghost town" status and local wineries. The town owes its existence mainly to two ore bodies that formed about 1.75billion years ago along a ring fault in the caldera of an undersea volcano. Tectonic plate movements, plate collisions, uplift, deposition, erosion, and other geologic processes eventually exposed the tip of one of the ore bodies and pushed the other close to the surface, both near Jerome. In the late 19th century, the United Verde Mine, developed by William A. Clark, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mazatzal Orogeny
The Mazatzal orogeny was an orogenic event in what is now the Southwestern United States from 1650 to 1600 Mya in the Statherian Period of the Paleoproterozoic. Preserved in the rocks of New Mexico and Arizona, it is interpreted as the collision of the 1700-1600 Mya age Mazatzal island arc terrane with the proto-North American continent. This was the second in a series of orogenies within a long-lived convergent boundary along southern Laurentia that ended with the ca. 1200–1000 Mya Grenville orogeny during the final assembly of the supercontinent Rodinia, which ended an 800-million-year episode of convergent boundary tectonism. Description Age and isotope data show that southern North America is composed of a series of northeast-trending provinces representing island arc terranes accreted onto the 1800 Mya core of Laurentia. These are the Yavapai province (1800–1700 Mya), the Mazatzal province (1700–1650 Mya), the Granite-Rhyolite province (1500–1300 Mya), and the L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yavapai Group
The Yavapai are a Native American tribe in Arizona. Historically, the Yavapai – literally “people of the sun” (from ''Enyaava'' “sun” + ''Paay'' “people”) – were divided into four geographical bands who identified as separate, independent peoples: the Ɖulv G’paaya, or Western Yavapai; the Yaavpe', or Northwestern Yavapai; the Gwev G’paaya, or Southeastern Yavapai; and the Wiipukpaa, or Northeastern Yavapai – Verde Valley Yavapai. Another Yavapai band, which no longer exists, was the Mađqwarrpaa or "Desert People." Its people are believed to have mixed with the Mojave and Quechan peoples. The Yavapai have much in common with their linguistic relatives to the north, the Havasupai and the Hualapai. Often the Yavapai were mistaken as Apache by American settlers, who referred to them as "Mohave-Apache," "Yuma-Apache," or "Tonto-Apache". Before the 1860s, when settlers began exploring for gold in the area, the Yavapai occupied an area of approximately 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurentia
Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America. Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and also the northwestern part of Scotland, known as the Hebridean Terrane. During other times in its past, Laurentia has been part of larger continents and supercontinents and itself consists of many smaller terranes assembled on a network of Early Proterozoic orogenic belts. Small microcontinents and oceanic islands collided with and sutured onto the ever-growing Laurentia, and together formed the stable Precambrian craton seen today. The craton is named after the Laurentian Shield, through the Laurentian Mountains, which received their name from the Saint Lawrence River, named after Lawrence of Rome. Interior platform In eastern and central Canada, much of the sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Arc
A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc located further from the subducting plate than the trench. The oceanic plate is saturated with water, mostly in the form of hydrous minerals such as micas, amphiboles, and serpentine minerals. As the oceanic plate is subducted, it is subjected to increasing pressure and temperature with increasing depth. The heat and pressure break down the hydrous minerals in the plate, releasing water into the overlying mantle. Volatiles such as water drastically lower the melting point of the mantle, causing some of the mantle to melt and form magma at depth under the overriding plate. The magma ascends to form an arc of volcanoes parallel to the subduction zone. Volcanic arcs are distinct from volcanic chains formed over hotspots in the middle of a tec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface. Various forms of metamorphism exist, including regional, contact, hydrothermal, shock, and dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved. Metamorphism occurring at increasing pressure and temperature conditions is known as ''prograde metamorphism'', while decreasing temperature and pressure characterize ''retrograde metamorphism''. Metamorphic petrology is the study of metamorphism. Metamorphic petrol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mazatzal Group
The Mazatzal Group is a group of geologic formations that crops out in portions of central Arizona, US. Detrital zircon geochronology establishes a maximum age for the formation of 1660 to 1630 million years (Mya), in the Statherian period of the Precambrian. The group gives its name to the Mazatzal orogeny, a mountain-building event that took place between 1695 and 1630 Mya. Description The Mazatzal Group consists mostly of fine-grained light-brown to gray quartzite which often shows cross-bedding; metaconglomerate containing clasts up to or more in size; and occasional lenses, up to in thickness, of maroon to gray argillite showing ripple marks and mudcracks. The lower beds of the group are intruded by rhyolite domes and sills. The total thickness of the group is up to . The group lies disconformably on top of the Red Rock Rhyolite and is in turn overlain by the Hopi Springs Shale. The group crops out in the Mazatzal Mountains, where it has been strongly deformed (with up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metavolcanic
Metavolcanic rock is volcanic rock that shows signs of having experienced metamorphism. In other words, the rock was originally produced by a volcano, either as lava or tephra. The rock was then subjected to high pressure, high temperature or both, for example by burial under younger rocks, causing the original volcanic rock to recrystallize. Metavolcanic rocks are sometimes described informally as ''metavolcanics''. When it is possible to determine the original volcanic rock type from the properties of the metavolcanic rock (particularly if the degree of metamorphism is slight), the rock is more precisely named by appylying the prefix ''meta-'' to the original rock type. For example, a weakly metamorphosed basalt would be described as a ''metabasalt'', or a weakly metamorphosed tuff as a ''metatuff''. Metavolcanic rock is commonly found in greenstone belt Greenstone belts are zones of variably metamorphosed mafic to ultramafic volcanic sequences with associated sedimentar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Period (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
