SPATIAL-DISTRIBUTION PROFILES OF MAGNESIUM AND STRONTIUM IN SPELEOTHEMS USING LASER-INDUCED BREAKDOWN SPECTROMETRY

Laser-induced breakdown spectrometry (LIBS) has been applied to spatia lly locate several atomic species in speleothems taken from the Nerja' s Cave (Malaga, Spain). Spatial distribution profiles of Mg at 285.21 nm and Sr at 407.77 nm were obtained while the laser was rastered thro ugh different paths along the sample. These elements were selected due to their importance as palaeoclimatic indicators. The 532 nm output o f a Nd:YAG laser was used to irradiate the samples and generate the pl asma that was spectrally analyzed and detected by using an intensified CCD detector. The signals were normalized to the Ca line to minimize pulse-to-pulse fluctuations in the laser source. Several studies were carried out to check for the point-to-point heterogeneity of the natur al speleothem.