Editing Rochechouart impact structure (section)

== Rochechouart projectile ==
Owing to the prominence of the siderophile contamination,<ref name=":4" /><ref name=":10">{{Cite journal|last=Janssens M.-J., Hertogen J., Takahashi H., Anders E., and Lambert P.|date=1977|title=Rochechouart meteorite crater: Identification of projectile|journal=Journal of Geophysical Research|volume=82-5|issue=5|pages=750–758|bibcode=1977JGR....82..750J|doi=10.1029/JB082i005p00750}}</ref> a cometary projectile seems unlikely. The impactor was an asteroid. The earliest identification works<ref name=":10" /> involved the same heavy techniques and the same diagnostic elements ([[Iridium|Ir]], [[Osmium|Os]] and other [[siderophile element]]s) as those that became famous in the early 1980s with the identification of the extraterrestrial signal at the K–T boundary worldwide.<ref name=":5" /> Since then the two extreme projectile types, iron meteorite and chondrite, have been argued by the successive workers.<ref name=":10" /><ref>{{Cite journal|last=Horn W., and El Goresy A.|date=1980|title=The Rochechouart crater in France: stony and not Iron meteorite?|journal=Lunar Planetary Science XI, Lunar and Planetary Institute, Houston|pages=468–470}}</ref><ref>{{Cite journal|last=Koeberl C., Shukolyukov A., and Lugmair G. W.|date=2007|title=Chromium isotopic studies of terrestrial impact craters: Identification of meteoritic components at Bosumtwi, Clearwater East, Lappajärvi, and Rochechouart|journal=Earth and Planetary Science Letters|volume=256|issue=3–4|pages=534–546|bibcode=2007E&PSL.256..534K|doi=10.1016/j.epsl.2007.02.008}}</ref> The most recent studies seems to agree with a special type of achondrite, a mix by impact of iron meteorite and silicates formerly designated as ''non magmatic'' iron meteorites.<ref>{{Cite journal|last=Tagle, R., Schmitt, R.T., and Erzinger, J.|date=2009|title=Identification of the projectile component in the impact structures Rochechouart, France, and Sääksjärvi, Finland: Implications for the impactor population for earth|journal=Geochimica et Cosmochimica Acta|volume=73|issue=16|pages=4891–4906|doi=10.1016/j.gca.2009.05.044|bibcode=2009GeCoA..73.4891T}}</ref>