LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS) APPLIED TO THE CHARACTERIZATION AND CONSERVATION OF ANTHROPOLOGICAL AND ARCHAEOLOGICAL PIECES

G.M. BILMES,; F. C. ALVIRA; A. A. ORSETTI; F. RAMÍREZ ROZZI

Buenos Aires

Congreso; Ninth biennial international conference of the infrared and raman users group; 2010

Infrared and raman users group

Laser Induced Breakdown Spectroscopy, (LIBS) is a non contact cuasi non-destructive technique that allows the determination of the elemental composition of practically any sample, with some advantages over other methods such as: minimum amount of sample and no preparation is required; possibility of real time depth profiling, and in situ measurements with portable instruments. LIBS is based on the ablation of the surface sample by using a laser pulse of relatively short duration and appropriate fluence to produce a plasma. The spectroscopic analysis of the plasma allows identifying the composition of the sample. In this work we present applications of LIBS to the determination of the elementary composition of unique pieces in anthropology and archaeology. We have detected and measured trace elements, as strontium and magnesium, in Homo-Sapiens teeth, with the aim to obtain information about alimentary habits of individuals and populations. We have determined the elemental composition of objects and pigments belonging to different South American pre-Columbian cultures as bracelets, masks, etc; Finally, in order to implement the appropriate conservation treatment, we used LIBS to identify the composition of 18 objects rescued from the sea, belonging to the British war corvette H.M.S.SWIFT, sank in 1770, at the Patagonian coast, in the Deseado Ria of Santa Cruz, Argentina.