Publication

Notre premier papier sur les applications de la LIBS en géologie est en ligne dans la revue Spectrochimica Acta Part B: Atomic Spectroscopy

Testing a portable Laser-induced Breakdown Spectroscopy system on geological samples

Jozef Rakovský^a^,^b^,, Olivier Musset^a, JeanFrançois Buoncristiani^c, Vincent Bichet^d, Fabrice Monna^e, Pascal Neige^c, Pavel Veis^b^,^f`

^a Laboratoire interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS – Université de Bourgogne, 9 Av. A. Savary, BP 47 870, F −21078 DIJON Cedex, France
^b Department of Experimental Physics FMFI, Comenius University, Mlynská dolina, 842 48 Bratislava, Slovakia
^c Laboratoire Biogéosciences, UMR CNRS 6282 – Université de Bourgogne, 6 Boulevard Gabriel 21000 Dijon, France
^d Laboratoire Chrono-Environnement, UMR CNRS 6249 – Université de Besançon, 16 Route de Gray 25000 Besançon, France
^e Laboratoire ARTéHIS, UMR CNRS 6298 – Université de Bourgogne, 6 Boulevard Gabriel 21000 Dijon, France
^f State Geological Institute of Dionýz Štúr, Mlynská dolina 1, 817 04 Bratislava 11, Slovakia

Abstract

This paper illustrates the potentialities of a home-made portable LIBS (Laser-Induced Breakdown Spectroscopy) instrument in Earth sciences, more particularly in geochemically recognizing (i) tephra layers in lacustrine sediments and (ii) fossilization processes in ammonites. Abundances for selected lines of Al, Ca, Fe, Ti, Ba and Na were determined in lacustrine chalk sediments of the Jura, where the Laacher See Tephra (LST) layer is recorded. A statistical treatment of elemental maps produced from the section of a sedimentary column containing the LST event allows instrumental conditions to be optimized. Accumulating spectra from close shot positions gives better results than multiplying shots at the same location. A depth profile method was applied to study ammonite fossilization (pyritization, phosphatization) processes. Depth variations of Fe, Ca, Al intensities, and Fe/Ca and Al/Ca ratios provide indications about pyritization, but phosphatization processes cannot be determined with our device.