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Strangways Crater
Strangways is a large impact structure, the eroded remnant of a former impact crater, located in the Northern Territory of Australia about east-south-east of the town of Mataranka. It was named after the nearby Strangways River. The location is remote and difficult to access. Its age has been determined as approximately 646 Ma. Description The circular topographic feature that marks the site was originally thought to be volcanic, with an impact origin first proposed in 1971 after the discovery of evidence diagnostic of impact including shatter cones and shocked quartz. The circular topographic feature is about in diameter and lies within Mesoproterozoic sedimentary rocks of the McArthur Basin. However, this is only a relic of the original crater after considerable erosion. Estimates of the original rim diameter vary between different researchers in the range ; the Earth Impact Database prefers a diameter of . The age of the impact event has been determined at 646 ± 42 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landsat Program
The Landsat program is the longest-running enterprise for acquisition of satellite imagery of Earth. It is a joint NASA / United States Geological Survey, USGS program. On 23 July 1972, the Landsat 1, Earth Resources Technology Satellite was launched. This was eventually renamed to Landsat 1 in 1975. The most recent, Landsat 9, was launched on 27 September 2021. The instruments on the Landsat satellites have acquired millions of images. The images, archived in the United States and at Landsat receiving stations around the world, are a unique resource for global change research and applications in agriculture, cartography, geology, forestry, regional planning, surveillance and education, and can be viewed through the U.S. Geological Survey (USGS) "EarthExplorer" website. Landsat 7 data has eight spectral bands with Image resolution#Spatial resolution, spatial resolutions ranging from ; the temporal resolution is 16 days. Landsat images are usually divided into scenes for easy do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shocked Quartz
Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. Under intense pressure (but limited temperature), the crystalline structure of quartz is deformed along planes inside the crystal. These planes, which show up as lines under a microscope, are called planar deformation features (PDFs), or shock lamellae. Discovery Shocked quartz was discovered following underground nuclear weapons testing, which generated the intense pressures required to alter the quartz lattice. Eugene Shoemaker showed that shocked quartz is also found inside craters created by meteor impact, such as the Barringer Crater and Chicxulub crater. The presence of shocked quartz supports that such craters were formed by impact, because a volcanic eruption would not generate the required pressure. Lightning is now known to contribute to the surface record of shocked quartz grains, complicating identification of hypervelocity impact features. Formation Shocked q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian Australia
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fossil re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterozoic Impact Craters
The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided into three geologic eras (from oldest to youngest): the Paleoproterozoic, Mesoproterozoic, and Neoproterozoic. The Proterozoic covers the time from the appearance of oxygen in Earth's atmosphere to just before the proliferation of complex life (such as trilobites or corals) on the Earth. The name ''Proterozoic'' combines two forms of ultimately Greek origin: meaning 'former, earlier', and , 'of life'. The well-identified events of this eon were the transition to an oxygenated atmosphere during the Paleoproterozoic; the evolution of eukaryotes; several glaciations, which produced the hypothesized Snowball Earth during the Cryogenian Period in the late Neoproterozoic Era; and the Ediacaran Period (635 to 538.8 Ma) which is characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of The Northern Territory
Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * 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 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 student magazine for the University of Nottingham, England * ''Bathimpa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Impact Craters In Australia
This list includes all 27 confirmed impact craters in Australia as listed in the Earth Impact Database.Bevan, Alex. and Ken McNamara (2009) ''Australia's meteorite craters'' Welshpool, W. A. : Western Australian Museum, 2nd ed. (pbk.) and other sources provide a contrast in methodology and limitations to the information in the EID Impact craters - confirmed Unconfirmed impact craters The following craters are officially considered "unconfirmed" because they are not listed in the Earth Impact Database. Due to stringent requirements regarding evidence and peer-reviewed publication, newly discovered craters or those with difficulty collecting evidence generally are known for some time before becoming listed. However, entries on the unconfirmed list could still have an impact origin disproven. See also * Impact craters * Impact events * Bolides and Meteorites * Earth Impact Database – primary source * Traces of Catastrophe book from Lunar and Planetary Institute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Register Of The National Estate
The Register of the National Estate was a heritage register that listed natural and cultural heritage places in Australia that was closed in 2007. Phasing out began in 2003, when the Australian National Heritage List and the Commonwealth Heritage List were created and by 2007 the Register had been replaced by these and various state and territory heritage registers. Places listed on the Register remain in a non-statutory archive and are still able to be viewed via the National Heritage Database. History The register was initially compiled between 1976 and 2003 by the Australian Heritage Commission, after which the register was maintained by the Australian Heritage Council. 13,000 places were listed. The expression "national estate" was first used by the British architect Clough Williams-Ellis, and reached Australia in the 1970s.Heritage of Australia, pp. 9–13 It was incorporated into the ''Australian Heritage Commission Act 1975'' and was used to describe a collection o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometric Dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of Earth itself, and can also be used to date a wide range of natural and man-made materials. Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale. Among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating. By al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McArthur Basin
The McArthur Basin is a large intracratonic sedimentary basin in northern Australia, with an exposed area of about 180,000 km2. Most of it lies within the northeastern Northern Territory, but extends over the border into the state of Queensland. The basin contains thick (locally up to 12 km) marine and non-marine sedimentary rocks which were deposited from the late Paleoproterozoic to the early Mesoproterozoic (1800-1430 Ma). The basin also contains some volcanic rocks and related intrusive igneous rocks. The McArthur Basin hosts the world-class McArthur River mine (HYC) zinc-lead-silver deposit (not to be confused with McArthur River mine in Canada) and several smaller mineral and diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, ... deposits. References * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter). The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus was formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies (marine snow). Sedimentation may also occur as dissolved minerals precipitate from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoproterozoic
The Mesoproterozoic Era is a geologic era that occurred from . The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic), but little is known about them. The continental masses of the Mesoproterozoic were more or less the same ones that exist today, although their arrangement on the Earth's surface was different. Major events and characteristics The major events of this era are the breakup of the Columbia supercontinent, the formation of the Rodinia supercontinent, and the evolution of sexual reproduction. This era is marked by the further development of continental plates and plate tectonics. The supercontinent of Columbia broke up between 1500 and 1350 million years ago, and the fragments reassembled into the supercontinent of Rodinia around 1100 to 900 million years ago, on the time boundary between the Mesoproterozoic and the subsequent Neoproterozoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shatter Cone
Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the range of . Morphology Shatter cones have a distinctively conical shape that radiates from the top (''apex'') of the cones repeating cone-on-cone in large and small scales in the same sample. Sometimes they have more of a spoon shape on the side of a larger cone. In finer-grained rocks such as limestone, they form an easily recognizable "horsetail" pattern with thin grooves (''striae''). However, the word "striae" should not be used to describe shatter cones, as that is considered misleading. Coarser grained rocks tend to yield less well developed shatter cones, which may be difficult to distinguish from other geological formations such as slickensides. Geologists have various theories of what causes shatter cones to form, including compress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
