Martian meteorite Teghaza 001 formed at least 4.1 billion years ago, sampling ancient crust

Teg 001 is a slowly cooled igneous rock whose composition, mineralogy and texture differ from other Martian meteorites. It shows signs of reactions with fluids.

Researchers described the Martian meteorite Teghaza 001 (Teg 001), a slowly cooled igneous rock that formed at least 4.1 billion years ago, in a paper in Science. science.org Most known Martian meteorites are geologically young and do not represent the planet's surface, which is dominated by ancient rocks.

Its composition, mineralogy and texture differ from other Martian meteorites. According to the authors, Teg 001 is a sample of ancient crust that formed from a geochemically distinct mantle source with primordial composition.

The rock contains aqueously altered minerals. Bulk and mineral-specific oxygen isotope measurements indicate that it reacted with fluids enriched in 18O before an impact ejected it into space.