Goyder - Hypervelocity Impact Crater

Alternate Names
Local Language
Coordinates 13° 28' 32" S; 135° 2' 32" E
Notes
  1. Within Goyder River catchment in Arnhem Land, 120 km SE of the Liverpool structure.
Country Australia
Region Northern Territory
Date Confirmed 1996
Notes
  1. Confirmed by shatter cone outcrops in the faulted core of the structure, as well as planar deformation features within quartz in the central area (Haines, 1996).
Buried? No
Drilled? No
Target Type Sedimentary
Notes
  1. Proterozoic arentites.
Sub-Type Mudstone, Sandstone
Apparent Crater Diameter (km) 7 km
Age (Ma) 150 - 1325
Notes :
  1. The range of 1325 to 150 Ma is based on stratigraphic constraints. The crater is roughly estimated to be older than the Cretaceous cover rocks (Haines, 1996) (Haines, 2005).

Method :
  1. Stratigraphy
Impactor Type Unknown

Advanced Data Fields

Notes

Erosion
6
  1. Floor of structure exposed (Haines, 1996).
Final Rim Diameter
Unknown
Apparent Rim Diameter
7 km
  1. Poorly constrained. Based on comparisons with other terrestrial impact structures, the diameter ranges between 7 and 25 km (Haines, 1996).
Rim Reliability Index
4
  1. The thicknesses of the involved stratigraphic units of the central uplift could not be accurately determined and original surface position of the CU is unknown (Haines, 1996).
Crater Morphology
Complex
Central Uplift Diameter
>3km
Central Uplift Height
Unknown
Uplift Reliability Index
4
Structural Uplift
Unknown
Thickness of Seds
Target Age
Precambrian
Marine
No
Impactor Type
Other Shock Metamorphism
No
Shatter Cones
Yes
  1. Shatter cones occur in the central part of the structure; they are well-developed at only one locality (Haines, 1996). No shatter cones were observed in the outer annulus. Shatter cones are associated with petrographic evidence of shock metamorphism including PFs and PDFs in quartz grains (Haines, 1996).
Planar Fractures
Yes
  1. In all thin sections, most quartz grains desplay planar and curved sets of fractures" (Haines, 1996).
Planar Deformation Features
Yes
  1. PDFs in quartz (Haines, 1996).
Diaplectic Glass
No
Coesite
No
Stisovite
No
Crater Fill
LB
  1. "The sandstone [of the central region] is intensely brecciated" (Haines, 1996). Crater heavily eroded (Haines, 1996).
Proximal Ejecta
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

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P W Haines (1996) Goyder impact structure, Arnhem Land, Northern Territory, AGSO Journal of Australian Geology and Geophysics 16(4), Andrew Y Glikson (ed.), p. 561-566, Australian Geological Survey Organisation, Canberra, A.C.T., url