Strangways crater

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False colour Landsat image of Strangways crater (circular feature in centre); screen capture from NASA World Wind
Oblique false colour Landsat image draped over digital elevation model (x10 vertical exaggeration), Strangways crater; screen capture from NASA World Wind

Strangways is a large impact structure, the eroded remnant of a former impact crater, situated in the Northern Territory, Australia.[1] It was named after the nearby Strangways River. The location is remote and difficult to access.

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 16 km (9.9 mi) 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 24–40 km (15–25 mi);[3] the Earth Impact Database[1] prefers a diameter of 25 km (16 mi). The age of the impact event has been determined at 646 ± 42 Ma (Neoproterozoic) based on radiometric dating of impact melt rocks.[4]

References[edit]

  1. ^ a b "Strangways". Earth Impact Database. University of New Brunswick. Retrieved 2009-08-20. 
  2. ^ Guppy DJ, Brett R, Milton DJ (1971). "Liverpool and Strangways craters, Northern Territory; two structures of probable impact origin". Journal of Geophysical Research 76 (23): 5387–93. Bibcode:1971JGR....76.5387G. doi:10.1029/JB076i023p05387. 
  3. ^ Haines PW (2005). "Impact cratering and distal ejecta: the Australian record". Australian Journal of Earth Sciences 52 (4–5): 481–507. Bibcode:2001AuJES..52..481H. doi:10.1080/08120090500170351.  Abstract
  4. ^ Spray JG, Kelley SP, Dence MR (1999). "The Strangways impact structure, Northern Territory, Australia: geological setting and laser probe 40Ar/39Ar geochronology". Earth and Planetary Science Letters 172 (3–4): 199–211. Bibcode:1999E&PSL.172..199S. doi:10.1016/S0012-821X(99)00206-X.  Abstract

Coordinates: 15°12′S 133°35′E / 15.200°S 133.583°E / -15.200; 133.583