Examining natural rock varnish and weathering rinds with laser-induced breakdown spectroscopy for application to ChemCam on Mars

Nina L Lanza; Samuel M Clegg; Roger C Wiens; Rhonda E McInroy; Horton E Newsom; Matthew D Deans

doi:10.1364/AO.51.000B74

Examining natural rock varnish and weathering rinds with laser-induced breakdown spectroscopy for application to ChemCam on Mars

Appl Opt. 2012 Mar 1;51(7):B74-82. doi: 10.1364/AO.51.000B74.

Authors

Nina L Lanza¹, Samuel M Clegg, Roger C Wiens, Rhonda E McInroy, Horton E Newsom, Matthew D Deans

Affiliation

¹ Institute of Meteoritics, MSC03 2050, 1 University of New Mexico, Albuquerque, New Mexico 87131, USA. nlanza@lanl.gov

PMID: 22410929
DOI: 10.1364/AO.51.000B74

Abstract

A laser-induced breakdown spectroscopy (LIBS) instrument is traveling to Mars as part of ChemCam on the Mars Science Laboratory rover. Martian rocks have weathered exteriors that obscure their bulk compositions. We examine weathered rocks with LIBS in a martian atmosphere to improve interpretations of ChemCam rock analyses on Mars. Profile data are analyzed using principal component analysis, and coatings and rinds are examined using scanning electron microscopy and electron probe microanalysis. Our results show that LIBS is sensitive to minor compositional changes with depth and correctly identifies rock type even if the series of laser pulses does not penetrate to unweathered material.