The term impact structure is closely related to the terms impact crater or meteoriteimpact 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. Tycho crater on Earths moon. ... Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ... Tycho crater on Earths moon. ... This article is about the Solar System. ... This article is about impact craters, also known as meteor craters. ... Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ... World geologic provinces Oceanic crust 0-20 Ma 20-65 Ma >65 Ma Geologic provinces Shield Platform Orogen Basin Large igneous province Extended crust Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason))[1] is the science and study of the solid matter of a celestial body, its composition... ‹ The template below has been proposed for deletion. ... Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. ... A conical fragment of rock with regular thin grooves (striae) that radiate from the top (apex) of the cone. ... The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks and soils, and the cycles of matter and energy that transport the Earths chemical components in time and space, and their interaction with... Layers of Atmosphere - not to scale (NOAA) Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. ...
References
French BM (1998) Traces of Catastrophe. Lunar and Planetary Science Institute, Houston.[1]
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