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Alamo Bolide Impact
The Alamo bolide impact occurred 377–378 million years ago, when one or more hypervelocity objects from space slammed into shallow marine waters at a site that is now the Devonian Guilmette Formation of the Worthington Mountains and Schell Creek Range of southeastern Nevada; the event is named for breccias of metamorphosed crushed rock deposits, found near the town of Alamo, Nevada (the "Alamo Breccia"). This catastrophic impact event resulted in what is one of the best-exposed and has become the most accurately dated impact events; it occurred within the Frasnian age of the Devonian at about 377-378 Ma, a moment in time that was about 5.9 Ma prior to the Frasnian/Famennian extinction events, which it is unlikely to have affected. The actual impact site has not yet been significantly documented—even its precise diameter and its internal structural features are not yet clear enough to make speculations on the mass and trajectory genuinely useful. The "tectonic overprin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pahranagat Range
The Pahranagat Range is a mountain range in Lincoln County, Nevada. References See also * Pahranagat Valley * Pahranagat National Wildlife Refuge * Alamo bolide impact The Alamo bolide impact occurred 377–378 million years ago, when one or more hypervelocity objects from space slammed into shallow marine waters at a site that is now the Devonian Guilmette Formation of the Worthington Mountains and Schell Cr ... Mountain ranges of Nevada Mountain ranges of Lincoln County, Nevada {{LincolnCountyNV-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogeography
Palaeogeography (or paleogeography) is the study of historical geography, generally physical landscapes. Palaeogeography can also include the study of human or cultural environments. When the focus is specifically on landforms, the term paleogeomorphology is sometimes used instead. Paleomagnetism, paleobiogeography, and tectonic history are among its main tools. Palaeogeography yields information that is crucial to scientific understanding in a variety of contexts. For example, palaeogeographical analysis of sedimentary basins plays a key role in the field of petroleum geology, because ancient geomorphological environments of the Earth's surface are preserved in the stratigraphic record. Palaeogeographers also study the sedimentary environment associated with fossils for clues to the evolutionary development of extinct species. Palaeogeography is furthermore crucial to the understanding of palaeoclimatology, due to the impact of the positions of continents and oceans on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of The United States
Impact may refer to: * Impact (mechanics), a large force or mechanical shock over a short period of time * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal * Impact wrench, a socket wrench power tool capable of high torque Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *'' Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from ''Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Impact Craters
The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding Carboniferous period at Ma. It is the fourth period of both the Paleozoic and the Phanerozoic. It is named after Devon, South West England, where rocks from this period were first studied. The first significant evolutionary radiation of life on land occurred during the Devonian, as free- sporing land plants (pteridophytes) began to spread across dry land, forming extensive coal forests which covered the continents. By the middle of the Devonian, several groups of vascular plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants ( pteridospermatophytes) appeared. This rapid evolution and colonization process, which had begun during the Silurian, is known as the Silurian-Devonian Terrestrial Revolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Utah
The geology of Utah, in the western United States, includes rocks formed at the edge of the proto-North American continent during the Precambrian. A shallow marine sedimentary environment covered the region for much of the Paleozoic and Mesozoic, followed by dryland conditions, volcanism, and the formation of the basin and range terrain in the Cenozoic. Geologic history, stratigraphy, and tectonics The eastern Uinta Mountains near the Colorado line and the Raft River-Dove Creek Mountains contain the oldest rocks in Utah from more than two billion years ago. Rubidium-strontium dating of the Red Creek quartzite in 1965 indicated an age of 2.3 billion years. Other geologists found 2.4 billion-year-old schist and gneiss in the Albion Range Green Creek Complex. Prior to the 1960s, geologists inferred the Vishnu and Farmington Canyon gneiss and schist as Archean in age, but subsequent research indicated a formation between 1.6 and 1.5 billion years ago in the Proterozoic. From 1.75 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Nevada
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with 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. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, the evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pahranagat Valley
The Pahranagat Valley is a Tonopah Basin landform in Lincoln County, Nevada. The more fertile part of Pahranagat Valley is a narrow ribbon of green (no more than wide), like an oasis in the vast Nevada desert. It is approximately long, running north and south, and is watered by three large natural springs of water ( Hiko Springs, Crystal Springs, and Ash Springs) and many smaller ones as well. It has four lakes, two near the north end of the valley (Nesbitt Lake and Frenchie Lake) and two towards the south end ( Upper Pahranagat Lake and Lower Pahranagat Lake). The southern half of the valley, including the two lakes, is home to the Pahranagat Valley National Wildlife Refuge. Pahranagat Valley is bordered on the west by a range of mountains called the Mount Irish Range and then the Pahranagat Range. It is bordered on the east by the Hiko Range. State Route 318 and then U.S. Route 93 traverse the entire length of the valley. The more inhabited areas in Pahranagat Valle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Society Of America
The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchcock, John R. Procter and Edward Orton and has been headquartered at 3300 Penrose Place, Boulder, Colorado, US, since 1967. GSA began with 100 members under its first president, James Hall. In 1889 Mary Emilie Holmes became its first female member. It grew slowly but steadily to 600 members until 1931, when a nearly $4 million endowment from 1930 president R. A. F. Penrose Jr. jumpstarted GSA's growth. As of December 2017, GSA had more than 25,000 members in over 100 countries. The society has six regional sections in North America, three interdisciplinary interest groups, and eighteen specialty divisions. Activities The stated mission of GSA is "to advance geoscience research and discovery, service to society, stewardship of Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsunami
A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, landslides, glacier calvings, meteorite impacts and other disturbances) above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event. Tsunami waves do not resemble normal undersea currents or sea waves because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide. For this reason, it is often referred to as a tidal wave, although this usage is not favoured by the scientific community because it might give the false impression of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolide
A bolide is normally taken to mean an exceptionally bright meteor, but the term is subject to more than one definition, according to context. It may refer to any large Impact crater, crater-forming body, or to one that explodes in the atmosphere. It can be a synonym for a Meteoroid#Fireball, fireball, sometimes specific to those with an apparent magnitude of −4 or brighter. Definitions The word ''bolide'' (; from Italian language, Italian via Latin, ) may refer to somewhat different phenomena depending on the context in which the word appears, and readers may need to make inferences to determine which meaning is intended in a particular publication. An early usage occurs in ''Natural History (Pliny), Natural History'', where Pliny the Elder describes two types of prodigium, prodigies, "those which are called lampades and those which are called bolides". At least one of the prodigies described by Pliny (a "spark" that fell, grew to the "size of the moon", and "returned into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lapilli
Lapilli (: lapillus) is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. ''Lapilli'' is Latin for "little stones". By definition lapilli range from in diameter. A pyroclastic particle greater than 64 mm in diameter is known as a volcanic bomb when molten, or a volcanic block when solid. Pyroclastic material with particles less than 2 mm in diameter is referred to as volcanic ash. Formation Lapilli are spheroid-, teardrop-, dumbbell- or button-shaped droplets of molten or semi-molten lava ejected from a volcanic eruption that fall to earth while still at least partially molten. These granules are the direct result of liquid rock cooling as it travels through the air. Lapilli tuffs are a very common form of volcanic rock typical of rhyolite, andesite and dacite pyroclastic eruptions, where thick layers of lapilli can be deposited during a basal surge eruption. Most lapilli tuf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium
Iridium is a chemical element; it has the symbol Ir and atomic number 77. This very hard, brittle, silvery-white transition metal of the platinum group, is considered the second-densest naturally occurring metal (after osmium) with a density of as defined by experimental X-ray crystallography. 191Ir and 193Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes; the latter is the more abundant. It is one of the most corrosion-resistant metals, even at temperatures as high as . Iridium was discovered in 1803 in the acid-insoluble residues of platinum ores by the English chemist Smithson Tennant. The name ''iridium'', derived from the Greek word ''iris'' (rainbow), refers to the various colors of its compounds. Iridium is one of the rarest elements in Earth's crust, with an estimated annual production of only in 2023. The dominant uses of iridium are the metal itself and its alloys, as in high-performance spark plugs, crucibles for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
