Submitted 2005 to Origins of Life and Evolution of Biospheres

MARS PRIMORDIAL CRUST:

UNIQUE SITES FOR INVESTIGATING PROTO-BIOLOGIC PROPERTIES

Randall S. Perry^1,2 and William K. Hartmann³

¹Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, South Kensington Campus Imperial College London, SW7 2AZ

²Planetary Science Institute, Seattle WA, 98115

³Planetary Science Institute, Tucson AZ, 85719

Abstract. The Martian meteorite collection suggests that intact outcrops or boulder-scale fragments of the 4.5 Ga Martian crust exist within tens of meters of the present day surface of Mars. Mars may be the only planet where such primordial crust samples, representing the first 100 Ma of the planet's environment, are available. The primordial crust has been destroyed on Earth by plate tectonics and other geological phenomena and is buried on the Moon under hundreds or thousands of meters of megaregoltih. Early Mars appears to have been remarkably similar to early Earth, and samples of rock from the first few Ma or first 100 Ma may reveal "missing link" proto-biological forms that could shed light on the transition from abiotic organic chemistry to living cells. Such organic snapshots of nascent life are unlikely to be found on Earth.