ASTEROID/COMET IMPACT BRECCIA (CUT SLICE) - Sudbury Impact Structure, Ontario, Canada
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IMPACT BRECCIA
From the Sudbury Impact Structure,
Ontario, Canada
1.85 billion years old
1.85 billion years old
A cut slice of the oldest impact breccia, or suevite, yet found. It consists of pulverised rock created by the immense pressures and temperatures associated with the impact of a giant asteroid or comet.
This example is from the Sudbury Basin in Ontario which is one of the largest known impact structures on Earth. The asteroid or comet is estimated to have been 10 to 15 kilometres in diameter and travelling up to 20 kilometres per second. The energy of the impact instantly melted and vapourised hundreds of cubic kilometers of rock and ejected much of it high into the air. The effects of the impact would have been felt globally.
This specimen is known as Onaping Breccia. It is a ‘fallback breccia’ composed of melted glass and fragments of the local rock. The crater subsequently filled with magma which deposited nickel, copper and other metals. As a result, the Sudbury area is now a major mining community.
Research in 2014 concluded that a comet may have been responsible for the impact rather than an asteroid.
Size: 6 x 5 x 0.4 centimetres
Weight: 23 grams