SHATTER CONES - Shock-induced structures formed by a meteorite impact - Germany
« backSHATTER CONES - Key evidence for a catastrophic meteorite impact
15 million years old
Steinheim Basin, near Ulm, Southern Germany
Shatter cones are rare geological features that are proof of giant meteorite impacts. They are characteristic, conical-shaped ‘horsetail’ fracture planes that are formed when rock is subjected to extreme shock. They also indicate the direction the shock wave was moving. Only giant meteorite impacts or underground nuclear explosions can produce these structures.
This example dates from the Miocene Period, about 15 million years ago, when an asteroid entered the Earth’s atmosphere and impacted on southern Germany creating what is known as the Ries Crater. Some idea of the pressure waves induced in the rock at the impact site can be gained by the fact that the 1 kilometre diameter asteroid was travelling at about 20 kilometres a second.
About 40 kilometres south-west of the Ries Crater is the Steinheim Basin crater which is the same age as The Ries indicating that this was a ‘double asteroid’, perhaps as a result of a single object breaking apart in the atmosphere. The underlying rock of fine-grained Upper Jurassic limestone here has preserved the shatter cone structures very well.
A fine example of shatter cones that displays well.
Click on a picture for a larger image.
Please note that the photographs are taken using oblique lighting to make the structures easier to see.
Size: 8 x 8 x 5.5 centimetres
Weight: 274 grams