Darwin Glass
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Darwin Glass is a natural glass found to the east of Mount Darwin in the area known as the Darwin Meteorite impact crater in West Coast Tasmania just east of the West Coast Range.
Fragments of this glass are found scattered over a 400 km2 area. Such an area is called a strewn field. The glass is light to dark green, white or black. The glass takes the form of twisted masses, fragments or chunks up to 10 cm. Internally it has a flowing texture caused by lines of elliptical bubbles.
It has been dated at 816,000 years old. The glass is an impactite resulting from the melting of local rocks due to the impact of a large meteorite. The crater left by this meteorite is at 42.18.39 South, 145.39.41 East. The crater is 1.2 km in diameter, 230 meters deep and filled with sediments. The meteorite was from 20 to 50 meters in diameter and released 20 megatons of energy.
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[edit] References
- Ching-Hua Lo et al, Laser Fusion argon-40/argon-39 ages of Darwin Impact Glasses, Metoeritica and Planetary Science 37, p1555 2002.
- Keiren T Howard, Peter Haines, Fire in the Sky above South West Tasmania. 17th Austalian Geliogical Conference
- K.T. Howard, Geochemical Systematics In Darwin Impact Glass, 66th Annual Meteoritical Society Meeting (2003)
