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Santa Marta Crater
Santa Marta crater is a newly confirmed impact crater in Piauí State, northeastern Brazil. It is in diameter and it is estimated to have formed between 100 and 66 Ma, during the Late Cretaceous. Description Its impact origin was first proposed by S. Master and J. Heymann in 2000 based primarily on satellite remote sensing data and was confirmed more than a decade later after conclusive evidence of shock metamorphism such as breccia and shatter cones were found.A. P. Crósta and M. A. Vasconcelos (2013)Confirmation Of The Impact Origin Of The Santa Marta Crater, Brazil 76th Annual Meteoritical Society Meeting See also * Umm al Binni lake Umm al Binni lake is a mostly dry lake within the Central Marshes in Maysan Governorate in southern Iraq. The wide lake is approximately northwest of the Tigris–Euphrates confluence. Because of its shape, location, and other details, it was f ... References Impact craters of Brazil Cretaceous impact craters Cretaceous Braz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parnaíba Basin
The Parnaíba Basin (Portuguese: ''Bacia do Parnaíba'') is a large cratonic sedimentary basin located in the North and Northeast portion of Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area .... About 50% of its areal distribution occurs in the state of Maranhão, and the other 50% occurring in the state of Pará, Piauí, Tocantins, and Ceará, Cearâ. It is one of the largest Paleozoic basins in the South American Plate, South American Platform. The basin has a roughly Ellipse, ellipsoidal shape, occupies over 600,000 km2, and is composed of ~3.4 km of mainly Paleozoic sedimentary rock that overlies localized rifts. The basin as named after the Parnaíba River, which is approximately 1,400 km (870 mi) long, and runs relatively parallel to the major axis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area and the seventh most populous. Its capital is Brasília, and its most populous city is São Paulo. The federation is composed of the union of the 26 States of Brazil, states and the Federal District (Brazil), Federal District. It is the largest country to have Portuguese language, Portuguese as an List of territorial entities where Portuguese is an official language, official language and the only one in the Americas; one of the most Multiculturalism, multicultural and ethnically diverse nations, due to over a century of mass Immigration to Brazil, immigration from around the world; and the most populous Catholic Church by country, Roman Catholic-majority country. Bounded by the Atlantic Ocean on the east, Brazil has a Coastline of Brazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piauí
Piaui (, ) is one of the states of Brazil, located in the country's Northeast Region. The state has 1.6% of the Brazilian population and produces 0.7% of the Brazilian GDP. Piaui has the shortest coastline of any coastal Brazilian state at 66 km (41 mi), and the capital, Teresina, is the only state capital in the northeast to be located inland. The reason for this is, unlike the rest of the area, Piaui was first colonised inland and slowly expanded towards the ocean, rather than the other way around. In the southeast of the state, the National Park of Serra da Capivara is a UNESCO World Heritage Site. The park has more than 400 archaeological sites and the largest concentration of rock paintings in the world, in a landscape dominated by canyons and caatinga. History The state has many notable archaeological sites, including Serra de Capivara National Park and Sete Cidades National Park, which are rich in remains of prehistoric Paleo-Indian and sedentary-based In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become eroded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaannum
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mean yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remote Sensing
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth and other planets. Remote sensing is used in numerous fields, including geography, land surveying and most Earth science disciplines (e.g. hydrology, ecology, meteorology, oceanography, glaciology, geology); it also has military, intelligence, commercial, economic, planning, and humanitarian applications, among others. In current usage, the term ''remote sensing'' generally refers to the use of satellite- or aircraft-based sensor technologies to detect and classify objects on Earth. It includes the surface and the atmosphere and oceans, based on propagated signals (e.g. electromagnetic radiation). It may be split into "active" remote sensing (when a signal is emitted by a satellite or aircraft to the object and its reflection detected by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Metamorphism
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorphic effects unequivocally associated with explosions and the difficulty in reaching sufficient pressures during such an event. Effects Mineral microstructures Planar fractures Planar fractures are parallel sets of multiple planar cracks or cleavages in quartz grains; they develop at the lowest pressures characteristic of shock waves (~5–8 GPa) and a common feature of quartz grains found associated with impact structures. Although the occurrence of planar fractures is relatively common in other deformed rocks, the development of intense, widespread, and closely spaced planar fractures is considered diagnostic of shock metamorphism. [...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 otherwise th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shatter Cones
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] |
Umm Al Binni Lake
Umm al Binni lake is a mostly dry lake within the Central Marshes in Maysan Governorate in southern Iraq. The wide lake is approximately northwest of the Tigris–Euphrates confluence. Because of its shape, location, and other details, it was first conjectured by Sharad Master, a geoarchaeologist, to represent an impact crater. However, these claims have been disputed, with other studies finding subsidence of the underlying rock a more plausible explanation. Evidence as an impact crater Based on the interpretation of satellite imagery, Sharad Master suggests the in diameter dry lake may be an impact crater based on its nearly circular, slightly polygonal rim shape, and contrasting shape to other lakes in the region. However, the circularity of its shape has been disputed, with a 2018 study finding that the northeastern and southwestern sections of the lake rim were straight, corresponding to the directions of regional faulting. As to its origin, Masters rejects karst topograp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of Brazil
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 * ''Bathimp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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