The Woodleigh crater was found on Woodleigh Station, east of
Shark Bay in Western Australia.
The crater may be up to 120km in diameter, although some estimates are closer to 40km. The larger estimate suggests a bolide (asteroid or
comet) 5km in diameter, which would make this the fourth largest impact structure in the world. However, a study presented at the Geological Society of America's 38th Annual Meeting in 2003 suggests a diameter closer to 60km.
The impact structure is entirely underground. The central uplift structure 20km in diameter was first detected by drilling activities in the late 1970s, however its significance as an impact structure was only realised in 1997 during a gravity survey. In 1999 a core sample was taken. The thin veins of melted glass, breccia, and shocked quartz found would have formed under pressures 100,000 times greater than atmospheric pressure at sea level, or between 10 and 100 times greater than those generated by volcanic or earthquake activity. Only a large impact could have generated such conditions.
The Woodleigh impact, originally thought to be Late Triassic or Late Permian, most likely dates to around 364 MYA, corresponding to a minor extinction event in the Late Devonian Period when around 40% of species disappeared.
The site is on Woodliegh Station private property and is no longer visible due to Erosion