X-Ray Techniques Applied to Surface Paintings of Ceramic Pottery Pieces from Aguada Culture (Catamarca, Argentina).

BERTOLINO, S., V. GALVÁN, A. CARRERAS, A. LAGUENS, G. A. DE LA FUENTE Y J. A. RIVEROS.

X-RAY SPECTROMETRY

Wiley Interscience

Año: 2009 vol. 38 p. 95 - 102

0049-8246

XRD, EDS, XRI and SEM techniques were applied to surface paintings of archaeological pottery from Aguada Ambato and Portezuelo styles (Catamarca, Argentina). Standard procedures are not always appropriate for such samples (paint layers are porous, non planar and discontinue). Image processing is necessary when chemical contrast is not discriminated. Soft x-ray lines (e.g. Fe L) are more revealing because those detected come from shallower depths, clearly depicting the composition of the paint layer. XRI, BEI and processed images were better than EDS spectra for compositional differentiation. These styles differ in mineralogy and chemistry suggesting that they are two distinctive entities not only on their designs but also on the materials chosen and the technology used. Aguada Portezuelo paints contain Ca (white), Fe-Mn (black), Fe-Mn-Ca (dark reddish) and Fe-Ca (reddish). The whites correspond to gehlenite, a firing product (possible firing temperature H 900-1000ºC); calcite and CaO occur in cases (firing temperatures < 900ºC).