Suevite is a rock consisting partly of melted material, typically forming a breccia containing glass and crystal or lithic fragments, formed during an impact event. It forms part of a group of rock types and structures that are known as impactites.
The word "suevite" is derived from "Suevia", Latin name of Swabia. It was suggested by Adolf Sauer in 1901. [1] [2]
Suevite is thought to form in and around impact craters by the sintering of molten fragments together with unmelted clasts of the country rock. Rocks formed from more completely melted material found in the crater floor are known as tagamites . Suevite is distinct from the pseudotachylite in an impact structure as the latter is thought to have formed by frictional effects within the crater floor and below the crater during the initial compression phase of the impact and the subsequent formation of the central uplift. [3]
Suevite is one of the diagnostic rock-types for large impact structures. It has been described from many of the larger impact structures identified on earth.
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.
The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore, but the crater is named after the onshore community of Chicxulub Pueblo. It was formed slightly over 66 million years ago when a large asteroid, about ten kilometers in diameter, struck Earth. The crater is estimated to be 180 kilometers in diameter and 20 kilometers in depth. It is the second largest confirmed impact structure on Earth, and the only one whose peak ring is intact and directly accessible for scientific research.
The Nördlinger Ries is an impact crater and large circular depression in western Bavaria and eastern Baden-Württemberg. It is located north of the Danube in the district of Donau-Ries. The city of Nördlingen is located within the depression, about 6 kilometres (3.7 mi) south-west of its centre.
The Chesapeake Bay impact crater is a buried impact crater, located beneath the mouth of Chesapeake Bay, United States. It was formed by a bolide that struck the eastern shore of North America about 35.5 ± 0.3 million years ago, in the late Eocene epoch. It is one of the best-preserved "wet-target" impact craters in the world.
Impactite is rock created or modified by one or more impacts of a meteorite. Impactites are considered metamorphic rock, because their source materials were modified by the heat and pressure of the impact. On Earth, impactites consist primarily of modified terrestrial material, sometimes with pieces of the original meteorite.
The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geological structure in Ontario, Canada. It is the third-largest known impact crater or astrobleme on Earth, as well as one of the oldest. The crater was formed 1.849 billion years ago in the Paleoproterozoic era.
The Boltysh crater or Bovtyshka crater is a buried impact crater in the Kirovohrad Oblast of Ukraine, near the village of Bovtyshka. The crater is 24 kilometres (15 mi) in diameter and its age of 65.39 ± 0.14/0.16 million years, based on argon-argon dating techniques, less than 1 million years younger than Chicxulub crater in Mexico and the Cretaceous–Paleogene boundary. The Chicxulub impact is believed to have caused the mass extinction at the end of the Cretaceous period, which included the extinction of the non-avian dinosaurs. The Boltysh crater is currently thought to be unrelated to the Chicxulub impact, and to have not generated major global environmental effects.
Gow is an impact crater in Saskatchewan, Canada.
Lappajärvi is a lake in Finland, in the municipalities of Lappajärvi, Alajärvi and Vimpeli. It is formed in a 23 km (14 mi) wide, partly eroded meteorite impact crater. The lake is part of Ähtävänjoki basin together with Lake Evijärvi that is located downstream (north) of it.
The Popigai impact structure is the eroded remnant of an impact crater in northern Siberia, Russia. It is tied with the Manicouagan structure as the fourth largest verified impact structure on Earth. A large bolide impact created the 100-kilometre (62 mi) diameter crater approximately 35 million years ago during the late Eocene epoch. It might be linked to the Eocene–Oligocene extinction event.
Rochechouart impact structure or Rochechouart astrobleme is an impact structure in France. Erosion has over the millions of years has mostly destroyed its impact crater, the initial surface expression of the asteroid impact leaving highly deformed bedrock and fragments of the crater's floor as evidence of it.
Roter Kamm is a meteorite crater, located in the Sperrgebiet, within the Namibian section of the Namib Desert, approximately 80 kilometres (50 mi) north of Oranjemund and 12 kilometres (7.5 mi) southwest of Aurus Mountain in the ǁKaras Region. The crater is 2.5 kilometres (1.6 mi) in diameter and is 130 metres (430 ft) deep. The age is estimated at 4.81 ± 0.5 Ma, placing it in the Pliocene. The crater is exposed at the surface, but its original floor is covered by sand deposits at least 100 metres (330 ft) thick.
The Steinheim crater is a meteorite crater in Steinheim am Albuch, Heidenheim County, Baden-Württemberg, Germany. The crater is located at the north-eastern end of the Swabian Alb, 40km west of the much larger (24-km-diameter) Nördlinger Ries crater.
Woodleigh is a large meteorite impact crater (astrobleme) in Western Australia, centred on Woodleigh Station east of Shark Bay, Gascoyne region. A team of four scientists at the Geological Survey of Western Australia and the Australian National University, led by Arthur J. Mory, announced the discovery in the 15 April 2000 issue of Earth and Planetary Science Letters.
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 2–30 GPa (290,000–4,350,000 psi).
Moldavite is a forest green, olive green or blue greenish vitreous silica projectile glass formed by a meteorite impact in southern Germany that occurred about 15 million years ago. It is a type of tektite and a gemstone.
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events.
The c. 80 km x 40 km sized Rubielos de la Cérida structure is a claimed impact feature located in Aragon, northeast Spain, north of Teruel purported to have formed during the Upper Eocene or Oligocene. The name is derived from the nearby village of Rubielos de la Cérida. The claim that the structure represents an impact feature is rejected by the majority of scientists, and the mainstream consensus is that the supposed structure is explained by non-impact related tectonic structures, namely the Jiloca-Calatayud graben and the Alfambra-Teruel graben.
As of June 2018, 12 confirmed impact craters have been found in Finland. They are listed below, sorted by original diameter.