Impact crater/structure | |
---|---|
Confidence | Confirmed |
Diameter | ~20 km (12 mi) |
Age | 1640-600 Ma Proterozoic |
Exposed | Yes |
Drilled | No |
Location | |
Location | Davenport Range |
Coordinates | 20°51′S134°53′E / 20.850°S 134.883°E Coordinates: 20°51′S134°53′E / 20.850°S 134.883°E |
Country | Australia |
State | Northern Territory |
Amelia Creek crater is an impact structure (or astrobleme), the eroded remnant of a former impact crater, located in the Davenport Range, Northern Territory, Australia. [1] It lies within a low range of Paleoproterozoic sedimentary and volcanic rocks, which are extensively folded and faulted, thus making an eroded impact crater difficult to recognize. It was only discovered by the identification of shatter cones near its centre. [2] The central shatter cone locality is surrounded by a 20 by 12 km (12.4 by 7.5 mi) area of anomalous deformation, the asymmetry being possibly related to very oblique impact, but may be at least partly due to the pre-existing structural complexity of the rocks. [3] This deformed zone gives the best estimate for the original size of the crater. Impact took place after folding of the Paleoproterozoic rocks but before deposition of Neoproterozoic and Cambrian rocks which overlie them, thus constraining the impact event to the interval between about 1660 and 600 Ma. [3]
Iytwelepenty / Davenport Range is a national park in the Northern Territory of Australia about 1,033 kilometres (642 mi) southeast of the territorial capital of Darwin. Amelia Creek crater, an ancient eroded impact crater lies within the Davenport Range in the area.
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 formed 1.849 billion years ago in the Paleoproterozoic era.
Acraman crater is a deeply eroded impact crater in the Gawler Ranges of South Australia. Its location is marked by Lake Acraman, a circular ephemeral playa lake about 20 kilometres (12 mi) in diameter. The discovery of the crater and independent discovery of its ejecta were first reported in the journal Science in 1986. The evidence for impact includes the presence of shatter cones and shocked quartz in shattered bedrock on islands within Lake Acraman.
The Arkenu structures, also known as the Arkenu craters, are a pair of prominent circular geological structures in eastern Libya. The structures are approximately 10 kilometres (6.2 mi) and 6.8 kilometres (4.2 mi) in diameter, and lie about 70 kilometres (43 mi) west of Jabal Arkanu on the eastern margin of the al-Kufrah Basin.
Foelsche is a partly buried impact structure, the eroded remnant of a former impact crater. It is situated about 85 km southeast of Borroloola in the Northern Territory, Australia, and named after the nearby Foelsche River. Although little of it is exposed at the surface, and no crater shaped topography is evident, the circular nature of the feature is obvious on aeromagnetic images, a factor that led to its discovery.
Goat Paddock is a 5 km-diameter near-circular bowl-shaped depression in a range of gently dipping Proterozoic sandstone in the Kimberley Region of northern Western Australia, 106 km west-southwest of Halls Creek. It is interpreted as an ancient meteorite impact crater, the evidence including breccia containing melted rocks, silica glass, shatter cones and shocked quartz. Drilling shows that the crater is filled with about 200 m of ancient lake sediments containing Early Eocene pollen, this age thus giving a minimum estimate for the age of the crater itself. The crater is not perfectly circular, but slightly elongated in a north–south direction, suggesting that the projectile struck at low angle from either the north or south.
Gosses Bluff is thought to be the eroded remnant of an impact crater. Known as Tnorala to the Western Arrente people of the surrounding region, it is located in the southern Northern Territory, near the centre of Australia, about 175 km (109 mi) west of Alice Springs and about 212 km (132 mi) to the northeast of Uluru. It was named by Ernest Giles in 1872 after Australian explorer William Gosse's brother Henry, who was a member of William's expedition.
Goyder is an impact structure, the eroded remnant of a former impact crater. It is situated in Arnhem Land in the Northern Territory, Australia, and was named after the nearby Goyder River. The impact occurred into Mesoproterozoic sedimentary rocks of the McArthur Basin. The deformed area is exposed at the surface and marked by a 3 km diameter ring of fractured and faulted sandstone, which is interpreted as the eroded relic of a central uplift ; the original crater rim, long since removed by erosion, being estimated at approximately 9–12 km diameter. Evidence for an impact origin includes the presence of shatter cones and shocked quartz in outcrops of deformed sandstone at the center of the site.
Kelly West is a deeply eroded impact crater situated in the central Northern Territory, Australia. It was discovered during Government geological mapping and first reported in 1973, the evidence for impact coming principally from an abundance of shatter cones at the site.
The Kentland structure, also known as the Kentland crater or the Kentland disturbed area, is an impact structure located near the town of Kentland in Newton County, Indiana, United States.
Keurusselkä is a lake in Central Finland between the towns of Keuruu to the north and Mänttä to the south. It covers an area of 117.3 km2 (45.3 sq mi). Its average depth is 6.4 m (21 ft) with a maximum depth of 40 m (130 ft). The surface lies at 105.4 m (346 ft) above sea level. The lake is 27 km (17 mi) long and is a part of the Kokemäenjoki water system. Keurusselkä gained international publicity in 2004 when a pair of amateur geologists discovered an ancient impact crater on the western shore of the lake.
Lawn Hill ‘crater’ refers to an Ordovician impact structure, the eroded remnant of a former impact crater, situated approximately 220 km north-north-west of Mount Isa in northwestern Queensland, Australia. The site is marked by an 18 km diameter ring of dolomite hills. The origin of this circular feature was uncertain until the discovery of shatter cones and shocked quartz from uplifted rocks at the centre was reported in 1987.
Liverpool is a meteorite impact crater situated in Arnhem Land within the Northern Territory, Australia. It was named after the nearby Liverpool River. Liverpool is remote and difficult to access. The crater has a raised, near-circular rim averaging about 1.6 km in diameter. It was first noticed by geologists during reconnaissance geological mapping in the 1960s, and although an impact origin was considered possible, this was not confirmed until a more detailed study was undertaken in 1970.
Shoemaker is an impact structure, the deeply eroded remnant of a former impact crater, situated in arid central Western Australia, about 100 km (62 mi) north-northeast of Wiluna. It is named in honour of planetary geologist Eugene Shoemaker.
Spider is an impact structure, the deeply eroded remnant of a former impact crater, situated in the Kimberley Region of northern Western Australia, 18 km east of the Mount Barnett Roadhouse on the Gibb River Road. Due to very rugged terrain the site is effectively inaccessible. The name is derived from the visually striking spider-like radiating ridges of quartzite prominently visible from the air or on satellite images.
Strangways is a large impact structure, the eroded remnant of a former impact crater, located in the Northern Territory of Australia about 65 kilometres (40 mi) 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.
The Yarrabubba crater is an impact structure, the eroded remnant of a former impact crater, situated in the northern Yilgarn Craton near Yarrabubba Station between the towns of Sandstone and Meekatharra, Mid West Western Australia. With an age of 2.229 billion years, it is one of the oldest known impact structures on Earth.
Glikson crater is an impact structure, the eroded remnant of a former impact crater, situated in the Little Sandy Desert of central Western Australia. A possible impact structure was first reported in 1997, and named after Australian geologist A. Y. Glikson, attention to the site being drawn by the presence of a prominent 14 km diameter ring-shaped aeromagnetic anomaly. The area within the ring contains sparse outcrop of uplifted and deformed Neoproterozoic sandstone, but is largely covered by sand dunes. The recent discovery of shatter cones and microscopic shock effects is reliable evidence for an impact origin. Deformation of the sandstone consistent with an impact origin extends out to a diameter of 19 km, which is the best estimate for the original diameter of the original crater. The ring-shaped aeromagnetic anomaly was probably caused by disruption of a horizontal layer of magnetic igneous rock, known as a sill, by the impact event. Nearby outcrops of dolerite have been dated at 508 ± 5 Ma (Middle Cambrian), and if this is the same rock causing the aeromagnetic anomaly, then the impact must be younger, probably of Paleozoic age.
The Santa Fe impact structure is an eroded remnant of a bolide impact crater in the Sangre de Cristo Mountains northeast of Santa Fe, New Mexico. The discovery was made in 2005 by a geologist who noticed shatter cones in the rocks in a decades-old road cut on New Mexico State Road 475 between Santa Fe and Hyde Memorial State Park. Shatter cones are a definitive indicator that the rocks had been exposed to a shock of pressures only possible in a meteor impact or a nuclear explosion.
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events.