LIBS is a relatively new elemental technique and is a type of atomic emission spectroscopy. A short pulse, focused high energy laser beam is used to ablate the material surface producing a short lived plasma plume. Atomic emission lines of the excited plasma can be resolved using spectroscopic observation around the visible wavelengths (200 to 900nm). The ablated area is very small and so the technique is considered non-invasive.
LIBS has been employed for geochemical exploration  and measurement of soil carbon .
A common problem is error introduced due to inconsistencies in the laser spark and resulting plasma.
1. Mosier-Boss, P. A., Lieberman, S. H. & Theriault, G. A. (2002) Field demonstrations of a direct push FO-LIBS metal sensor. Environmental Science & Technology, 36(18), 3968-3976.
2. Cremers, D. A., Ebinger, M. H., Breshears, D. D., Unkefer, P. J., Kammerdiener, S. A., Ferris, M. J., Catlett, K. M. & Brown, J. R. (2001) Measuring total soil carbon with laser-induced breakdown spectroscopy (LIBS). Journal of Environmental Quality, 30(6), 2202-2206.