title: Multi-block analysis coupled to laser-induced breakdown spectroscopy for sorting geological materials from caves.
abstract: In this study, multi-block analysis was applied for the first time to LIBS spectra provided by a portable LIBS system (IVEA Solution, France) equipped with three compact Czerny-Turner spectrometers covering the spectral ranges 200-397nm, 398-571nm and 572-1000nm. 41 geological samples taken from a laboratory-cave situated in the "Vézère valley", an area rich with prehistoric sites and decorated caves listed as a UNESCO world heritage in the south west of France, were analyzed. They were composed of limestone and clay considered as underlying supports and of two types of alterations referred as moonmilk and coralloid. Common Components and Specific Weights Analysis (CCSWA) allowed sorting moonmilk and coralloid samples. The loadings revealed higher amounts of magnesium, silicon, aluminum and strontium in coralloids and the saliences emphasized that among the three spectrometers installed in the LIBS instrument used in this work; that covering the range 572-1000nm was less contributive. This new approach for processing LIBS data not only provides good results for sorting geological materials but also clearly reveals which spectral range contains most of the information. This specific advantage of multi-block analysis could lead for some applications to simplify the design and to reduce the size of LIBS instruments.
authors.affiliation: IRAMAT-CRP2A, UMR CNRS 5060, Université Bordeaux Montaigne, Maison de l'Archéologie, Domaine Universitaire, Esplanade des Antilles, 33607 Pessac Cedex, France. Electronic address: ammarifatouna@gmail.com.
authors.forename: Faten
authors.initials: F
authors.lastname: Ammari
authors.affiliation: IRAMAT-CRP2A, UMR CNRS 5060, Université Bordeaux Montaigne, Maison de l'Archéologie, Domaine Universitaire, Esplanade des Antilles, 33607 Pessac Cedex, France.
authors.forename: Léna
authors.initials: L
authors.lastname: Bassel
authors.affiliation: PACEA, UMR CNRS 5199, Université Bordeaux, Bâtiment B8, Allée Geoffroy Saint Hilaire, CS 50023, 33615 Pessac Cedex, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Ferrier
authors.affiliation: I2M-TREFLE, UMR 5295 CNRS, Université Bordeaux, Pessac 33607, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Lacanette
authors.affiliation: IRAMAT-CRP2A, UMR CNRS 5060, Université Bordeaux Montaigne, Maison de l'Archéologie, Domaine Universitaire, Esplanade des Antilles, 33607 Pessac Cedex, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Chapoulie
authors.affiliation: CELIA, UMR CNRS 5107, Université Bordeaux, 351 Cours de la Libération, F-33405 Talence Cedex, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Bousquet
keywords: Caves; Common Components and Specific Weights Analysis (CCSWA); Coralloid; Laser-induced breakdown spectroscopy (LIBS); Moonmilk; Multi-block analysis