Yarrabubba - Hypervelocity Impact Crater
Alternate Names | |
Local Language | |
Coordinates |
27° 10' 0" S; 119° 49' 60" E Notes
|
Country | Australia |
Region | Western Australia |
Date Confirmed | 2003 Notes
|
Buried? | No |
Drilled? | No |
Target Type |
Crystalline
Notes
|
Sub-Type | Granite |
Apparent Crater Diameter (km) | 70 km |
Age (Ma) | 2229 ± 5 Notes :
Method :
|
Impactor Type | Unknown |
Advanced Data Fields
Notes
- Some breccia and impact melt rocks.
- Outer diameter of crater estimated between 30-70 km (Macdonald et al., 2003). The ~20 km central uplift anomaly is consistent with a diameter of ~70 km (Erickson et al., 2020). Based on flat aeromagnetic field diameter is 25 km (Macdonald et al., 2005). [Note, the previous diameter of 25 km appears to have been misread as the central uplift was estimated to be 11 to 25 km in diameter (Macdonald et al., 2003).]
- Central uplift diameter ranges between 11 and 25 km (Macdonald et al., 2003). No real crater-form preserved or visible from the ground, aerial photographs, or satellite images (Macdonald et al., 2003). A ~20 km magnetic anomaly has been interpreted as the remnant of a deeply buried central uplift. This would be consistent with an original crater diameter of ~70 km (Erickson et al., 2020).
- Monazite with shock twins, and granular microstructure. Zircon with shock twins, and FRIGN zircon(Erickson et al., 2020).
- Shatter cones developed in granite and range from up to 1 m in size to small reversed cones that are only about 10 cm in height. Most of the shatter cones are located within 1 m from a contact between a pegmatite vein and medium-grained Yarrabubba Granite. In general, shatter cones point upwards and have very divergent striations (Macdonald and Mitchell, 2003).
- PDFs and PFs in quartz (Macdonald et al., 2003).
- Multiple sets of PDF in quartz grains within granite but no PDF found in granophyre or pseudetachylites (Macdonald and Mitchell, 2003). "Zircon displays primary igneous growth zoning that is cross-cut by planar and subplanar shock microstructures, including {112} shock twins and {100} planar deformation bands" (Erickson et al., 2020).
- Crater-fill impactites are not preserved. Impact-generated, dyke-like bodies of melt rock outcrop as far as 3 km from the center of the structure. This melt rock has been named as Barlangi granophyre and is a sodic rhyolite (Erickson et al., 2020). "A 0.5 m thick, deeply weathered dike of allogenic breccia with a crushed matrix is located V4 km south of Barlangi Rock. The breccia contains angular clasts of granite, granular quartz, feldspars, and glassy material that may be impact melt"(Macdonald et al., 2003). Silica spherule in a Barlangi dyke (Fig. 3; Macdonald et al., 2003). "It appears that the majority of the large dike-like bodies at Yarrabubba are fault melts, or pseudotachylites"(Macdonald et al., 2003).
References
(2003) Erratum to “Yarrabubba—a large, deeply eroded impact structure in the Yilgarn Craton, Western Australia”, Earth and Planetary Science Letters 213, p. 235-247, url, doi:10.1016/j.epsl.2004.07.012
(2003) Yarrabubba, Western Australia: a large, deeply eroded, ancient impact structure in the Yilgarn Craton, Lunar and Planetary Science Conference, p. 1116-1116, Lunar and Planetary Science Conference, Houston, TX, url
(2003) Yarrabubba - a large, deeply eroded impact structure in the Yilgarn Craton, Western Australia, Earth and Planetary Science Letters 213(3-4), p. 235-247, url, doi:10.1016/S0012-821X(03)00322-4
(2004) The Yarrabubba structure, Western Australia-clues to identifying impact events in deeply eroded ancient cratons, Geological Society of Australia Abstracts 73, p. 227-227
(2005) Impact cratering and distal ejecta: the Australian record, Australian Journal of Earth Sciences 52(4-5), p. 481-507, url, doi:10.1080/08120090500170351
(2005) Hydrothermal processes associated with meteorite impact structures; evidence from three Australian examples and implications for economic resources, Australian Journal of Earth Sciences 52(4-5), p. 587-605, Blackwell Scientific Publications for the Geological Society of Australia, Melbourne, Victoria, url, doi:http://dx.doi.org/10.1080/08120090500170468
(2019) Shocked zircon and monazite ages establish Yarrabubba, Western Australia, as the Earth's oldest preserved impact structure, Large Meteorite Impacts VI, p. Abstract 5107, LPI Contribution No. 2136, url
(2020) Precise radiometric age establishes Yarrabubba, Western Australia, as Earth’s oldest recognised meteorite impact structure, Nature Communications 11(300), p. 1-8, Nature Research, url, doi:10.1038/s41467-019-13985-7