Shergottites

Martian Meteorite - Composition - Shergottites
... Roughly three-quarters of all Martian meteorites can be classified as Shergottites ... Shergottites are igneous rocks of mafic to ultramafic lithology ... found in Morocco in 2011) and Lherzolitic Shergottites, based on their crystal size and mineral content ...

Martian Meteorite - Origin
... Formation ages determined for many shergottites are variable and much younger, mostly ~150-575 Ma ... The chronological history of shergottites is not totally understood, and a few workers have suggested that some may actually have formed prior to the times given by their radiometric ages, a suggestion not ... Some of the shergottites also seem to form distinct groups according to their CRE ages and formation ages, again indicating ejection of several different shergottites from Mars by a single impact ...