Impact structure

Impact structure

The term impact structure is closely related to the terms impact crater or meteorite impact crater, and is used in cases where erosion or burial have destroyed or masked the original topographic feature with which we normally associate the term "crater". This is the fate of almost all old impact craters on Earth, unlike the ancient pristine craters preserved on the moon and most other rocky bodies in the solar system. Impact structure is synonymous with the less commonly used term astrobleme (literally "star wound"). Although the typical topographic expression of an impact crater may be gone, and any meteorite fragments that may once have been present, now long since eroded away, possible impact structures may be initially recognized by their anomalous geological character or geophysical expression, and finally confirmed by the presence of shocked minerals (particularly shocked quartz), shatter cones or geochemical evidence of extraterrestrial material.

ee also

* Impact event

References

* French BM (1998) Traces of Catastrophe. Lunar and Planetary Science Institute, Houston. [http://www.lpi.usra.edu/publications/books/CB-954/CB-954.intro.html]

External links

* [http://www.unb.ca/passc/ImpactDatabase Earth Impact Database]


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