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Projectile remnants in central peaks of lunar impact craters.
- Source :
- Nature Geoscience; Jun2013, Vol. 6 Issue 6, p435-437, 3p
- Publication Year :
- 2013
-
Abstract
- The projectiles responsible for the formation of large impact craters are often assumed to melt or vaporize during the impact, so that only geochemical traces or small fragments remain in the final crater. In high-speed oblique impacts, some projectile material may survive, but this material is scattered far down-range from the impact site. Unusual minerals, such as magnesium-rich spinel and olivine, observed in the central peaks of many lunar craters are therefore attributed to the excavation of layers below the lunar surface. Yet these minerals are abundant in many asteroids, meteorites and chondrules. Here we use a numerical model to simulate the formation of impact craters and to trace the fate of the projectile material. We find that for vertical impact velocities below about 12 km s<superscript>−1</superscript>, the projectile may both survive the impact and be swept back into the central peak of the final crater as it collapses, although it would be fragmented and strongly deformed. We conclude that some unusual minerals observed in the central peaks of many lunar impact craters could be exogenic in origin and may not be indigenous to the Moon. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 17520894
- Volume :
- 6
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- Nature Geoscience
- Publication Type :
- Academic Journal
- Accession number :
- 102364686
- Full Text :
- https://doi.org/10.1038/ngeo1828