| Shoemaker impact structure | |
|---|---|
| Teague Ring | |
 Shoemaker impact structure from space | |
| Impact crater/structure | |
| Confidence | Confirmed |
| Diameter |
|
| Age |
|
| Exposed | Yes |
| Drilled | No |
| Location | |
| Coordinates | 25°52′S120°53′E / 25.867°S 120.883°E /-25.867; 120.883 |
| Country | Australia |
| State | Western Australia |
| District | Mid West |
  Location of the impact structure in Australia | |
Shoemaker (formerly known asTeague Ring) is animpact structure, the deeply eroded remnant of a formerimpact crater, situated inarid centralWestern Australia, about 100 kilometres (62 mi) north-northeast ofWiluna.[1] It is named in honour of planetary geologistEugene Shoemaker.[2]
The prominent ring-like topographic feature, easily seen in satellite images, lies on the boundary between thePalaeoproterozoic Earaheedy Basin and theArchaeanYilgarn craton. The area contains a number of seasonalsalt lakes, the largest being Lake Teague.
The first suggestion that the ring-like topographic feature may be an impact structure was published in 1974.[3] Subsequent research revealed definitive evidence for this hypothesis, including the presence ofshatter cones andshocked quartz.[4][5][6] The feature has a central circular region of uplifted Archaean Granite (Teague Granite) about 12 kilometres (7.5 mi) in diameter, surrounded by a downwarped ring (ringsyncline) of sedimentary rocks with an outer limit of disturbance at about 30 kilometres (19 mi) diameter, which is a minimum estimate of the size of the original crater.[5]
The age of the impact event is uncertain. It must be younger than theTeague Granite in the centre, dated at 2648 ± 8Ma (million years ago).[5] The most commonly cited age of about 1630 Ma[4] represents a re-heating event affecting the granite; while this may be the impact event, it could simply be a regionaltectonic event.[5] More recent dating byK–Ar methods yield ages as young as 568 ± 20 Ma;[7] this age could also date the impact event or represent tectonic activity.[5]
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