Darwin Crater
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Darwin crater is a suspected meteorite impact crater in Western Tasmania, Australia. It is expressed as a 1.2 km diameter rimless circular flat-floored depression within mountainous and heavily forested terrain 26 km south of Queenstown. It lies east of the West Coast Range and just within the Franklin-Gordon Wild Rivers National Park.
The crater was discovered by geologist R.J. Ford in 1972 after a search for the source of Darwin glass,[1] an impact glass found over an area of >400 km2 of southwestern Tasmania.[2] Based on geophysical investigations and drilling, the crater is filled with up to 230 m of breccia capped by Pleistocene lake sediments.[3][4] Although definitive proof of an impact origin of the crater is lacking, the impact hypothesis is strongly supported by the relationship of the glass to the crater, and the stratigraphy and deformation of the crater filling material.[4]
Based on the assumption that the crater is the source of the glass, the age of Darwin Crater is given by the 816 ± 7 ka age of Darwin glass determined by argon dating methods.[5]
[edit] References
- ^ Ford, R.J. (1972). "A possible impact crater associated with Darwin glass". Earth and Planetary Science Letters 16 (2): 228–230. doi:.
- ^ Howard, K.T.; Haines, P.W. (2003). "Distribution And Abundance Of Darwin Impact Glass". Third International Conference on Large Meteorite Impacts.
- ^ Fudali, R.F.; Ford, R.J. (1979). "Darwin glass and Darwin crater - A progress report". Meteoritics 14: 283–296.
- ^ a b Howard, K.T.; Haines, P.W. (2007). "The geology of Darwin Crater, western Tasmania, Australia". Earth and Planetary Science Letters 260 (1-2): 328–339. doi:.
- ^ Lo, C.H.; Howard, K.T.; Chung, S.L.; Meffre, S. (2002). "Laser-fusion 40Ar/39Ar Ages of Darwin Impact Glass". Meteoritics & Planetary Science 37 (11): 1555–1562.
