Elemental fractionation in ultraviolet laser ablation sampling of igneous silicate minerals relevant to Mars

Laser ablation sampling LAS. has significant potential for remote terrestrial and extraterrestrial applications if fractionation can be understood and controlled. This study focuses on acmite, albite, augite, diopside, forsterite, and labradorite, silicate minerals that are relevant to Mars, Earth, the moon, and asteroids. The minerals were sampled using a frequency-quadrupled Nd:YAG laser and the samples were deposited as films on graphite substrates. Rutherford backscattering spectrometry and X-ray photoelectron spectroscopy measurements of the minerals and their films indicate sodium, magnesium, silicon, calcium, and iron fractionation. Oxygen fractionation was not indicated. A cation replacement mechanism is a potential source of fractionation. These minerals can be easily distinguished by their film compositions despite fractionation, indicating that ultraviolet laser ablation sampling is feasible for silicate minerals. q2000 Elsevier Science B.V. All rights reserved.