Skip to main content
padlock icon - secure page this page is secure

Evidence for a shock-metamorphic breccia within a buried impact crater, Lake Raeside, Yilgarn Craton, Western Australia

Buy Article:

$61.00 + tax (Refund Policy)

Mineral exploration drilling 60 km west of Leonora in 2008 intersected >95 m of poorly consolidated granitoid-dominated breccia at the base of a Cenozoic paleochannel beneath Lake Raeside. The breccia, initially interpreted as a kimberlite, is composed of poorly consolidated fragments of granitic gneiss, felsite and metamorphosed mafic rock within a matrix of fine to medium-grained breccia. Microscopic examination revealed quartz grains displaying well-developed planar deformation features (PDFs) dominated by the ω {1013} planar set, diaplectic silica glass and diaplectic plagioclase glass. These features constitute the diagnostic hallmarks of shock metamorphism owing to high-velocity impact of a large meteorite or asteroid. The PDFs in quartz grains of the breccia are distinctly different from metamorphic deformation lamellae produced tectonically or in diatremes. Airborne total magnetic intensity data suggest an outline of an 11 km-diameter crater, consistent with the significant thickness of the shock-metamorphosed breccia at >95 m, suggestive of the existence of a large impact structure.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Keywords: Graziella Caprarelli; Impact breccia; Lake Raeside; Yilgarn Craton; plagioclase glass; planar deformation features; silica glass

Document Type: Research Article

Affiliations: 1: Visiting Scientist, Geoscience Australia, PO Box 378, Canberra, Australia 2: Geological Survey of Western Australia, 100 Plain Street, East Perth, WA, Australia 3: Minerex Services Pty Ltd, Australia

Publication date: January 2, 2016

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more