Strangways crater explained

Strangways crater
Map:Northern Territory
Coordinates:-15.2°N 168°W
Confidence:Confirmed
Diameter:24-
Age:646 ± 42 Ma
Neoproterozoic
Exposed:Yes
Drilled:No
Bolide:Achondrite
Country:Australia
State:Northern Territory

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.[1] 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.[2] The circular topographic feature is about 16km (10miles) 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 24-;[3] the Earth Impact Database prefers a diameter of 25km (16miles). The age of the impact event has been determined at 646 ± 42 Ma (Neoproterozoic) based on radiometric dating of impact melt rocks.[4]

In 1996, the crater's site was listed on the now-defunct Register of the National Estate.[5]

See also

Notes and References

  1. Strangways . 2017-10-09.
  2. Guppy DJ, Brett R, Milton DJ . Liverpool and Strangways craters, Northern Territory; two structures of probable impact origin . Journal of Geophysical Research . 76 . 23. 1971 . 5387–93 . 10.1029/JB076i023p05387 . 1971JGR....76.5387G.
  3. Haines PW . Impact cratering and distal ejecta: the Australian record . Australian Journal of Earth Sciences . 52 . 4–5. 2005 . 481–507 . 10.1080/08120090500170351. 2005AuJES..52..481H . 128705406 . Abstract
  4. Spray JG, Kelley SP, Dence MR . The Strangways impact structure, Northern Territory, Australia: geological setting and laser probe 40Ar/39Ar geochronology . Earth and Planetary Science Letters . 172 . 3–4. 1999 . 199–211 . 10.1016/S0012-821X(99)00206-X . 1999E&PSL.172..199S. Abstract
  5. 28 May 1996. 7 April 2020.