Suevite
Encyclopedia
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 impactite
s.
of molten fragments together with unmelted clasts of the country rock. Wholesale melt rocks 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.
Virtual field-trips to impact structures (N.B. Site still partly under construction)
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
consisting partly of melted material, typically forming a breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
containing glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
and crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
or lithic
Lithic fragment (geology)
Lithic fragments, or lithics, are pieces of other rocks that have been eroded down to sand size and now are sand grains in a sedimentary rock. They were first described and named by Bill Dickinson in 1970. Lithic fragments can be derived from sedimentary, igneous or metamorphic rocks)...
fragments, formed during an impact
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
event. It forms part of a group of rock types and structures that are known as impactite
Impactite
Impactite is an informal term describing a rock created or modified by the impact of a meteorite. The term encompasses shock-metamorphosed target rocks, melts and mixtures of the two, as well as sedimentary rocks with significant impact-derived components .-Some localities:*Nördlinger Ries...
s.
Formation
Suevite is thought to form in and around impact craters by the sinteringSintering
Sintering is a method used to create objects from powders. It is based on atomic diffusion. Diffusion occurs in any material above absolute zero, but it occurs much faster at higher temperatures. In most sintering processes, the powdered material is held in a mold and then heated to a temperature...
of molten fragments together with unmelted clasts of the country rock. Wholesale melt rocks found in the crater floor are known as tagamites. Suevite is distinct from the pseudotachylite
Pseudotachylite
Pseudotachylite is a fault rock that has the appearance of the basaltic glass, tachylyte. It is dark in color and has a glassy appearance. However, the glass has normally been completely devitrified into very fine-grained material with radial and concentric clusters of crystals...
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.
Occurrence
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.- Nördlinger RiesNördlinger RiesThe Nördlinger Ries is a large circular depression in western Bavaria, Germany, located north of the Danube in the district of Donau-Ries. The city of Nördlingen is located about southwest of the centre of the depression....
- Sudbury BasinSudbury BasinThe Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geologic structure in Ontario, Canada. It is the second-largest known impact crater or astrobleme on Earth, as well as one of the oldest....
- Popigai craterPopigai craterThe Popigai crater in Siberia, Russia is tied with Manicouagan Crater as the fourth largest verified impact crater on Earth. A large bolide impact created the diameter crater 35.7 ± 0.2 million years ago during the late Eocene . The crater is 1½ hours from the outpost of Khatanga...
- Chicxulub craterChicxulub CraterThe Chicxulub crater is an ancient impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named...
- Kara craterKara craterKara is a meteor crater in the Yugorsky Peninsula, Nenetsia, Russia.It is 65 km in diameter and the age is estimated to be 70.3 ± 2.2 million years old . Impactite outcrops located on the Baydarata Gulf shore north-east of the crater imply that the original size of the crater, now greatly...
- Azuara impact structureAzuara impact structureThe 35–40 km-diameter Azuara impact structure is located in northeast Spain roughly 50 km south of Zaragoza. The name is attributed to the small town of Azuara located near the center of the structure. The first hint to a possible impact origin was given by Wolfgang Hammann as early as...
External links
Page on Suevites from website on Impact Structures by Kord Ernstson & Fernando ClaudinVirtual field-trips to impact structures (N.B. Site still partly under construction)