Provenance of pottery from Catamarca (northwest Argentina): a reconnaissance study

ZIMMERMANN, U.; BERTOLINO, S.R.; KRISKAUTZKY, N

Córdoba

Congreso; 3º Congreso Argentino de Arquemetría y 2º Jornadas Nacionales para el Estudio de Bienes Culturales; 2009

FAMAF, Museo de Antropología, CNEA

&amp;amp;amp;amp;lt;!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --&amp;amp;amp;amp;gt; Twenty five samples of pottery were taken from different sites close to the city of Catamarca (northwest Argentina). Time constraints of the finds are loose, but range from the Third Century to the early 16th Century. The main objective of this study at this stage is to register changes in composition or manufacturing techniques using petrographic and geochemical techniques. This database will then have further used to carry out detailed analyses. The pottery material is represented by pots with walls thicknesses of c. 1 cm, only a small number are thinner. Few samples are reddish in color while most of them are black. Few samples are painted with orange or red paint. XRD analyses reveal the abundance of illite, quartz and albite in all samples. Most of the sherds comprise iron-oxides and some plagioclase. Mostly muscovite occurs and less abundant is biotite, which is not reflected in the whole sample chemistry, and only one sample showed a peak in calcite and titanite. SEM analysis demonstrated no clear differences in the texture of the clay minerals in the sherds. Most of the samples display a homogeneous texture with a slight orientation of the clay minerals. Quartz grains are mostly sub-angular as are feldspar. The geochemical characteristics regarding the major elements are relatively similar for all samples but two. Sample TFNIII and PBS564 are lower in silica, enriched in K, Ti and Fe, although they are sampled from the same site as other shards. All other pottery samples match typical upper continental crust and typical average shale composition. Alteration indices, (CIA or K/Cs ratios) are low and point to a moderate altered source rock. However, those values might be controlled by the manufacturing process. Trace elements are homogeneous but for the two samples mentioned, slightly different, as the influence of a less fractionated source component is visible. Concentrations for incompatible (Th, Zr, La, f.e.) are lower and higher for compatible elements (Cr, Sc, Ti, f.e.), sugesting the use of a different clay source. Interestingly, Ta concentrations are mostly high, and Nb/Ta ratios are disturbed with mostly lower ratios (< 8) than found in normal terrestrial material. This points to a Ta enrichment, either caused by the manufacturing process, or the manufacturing material comprised such an anomaly. High Cs concentrations were observed in local Neoproterozoic rocks (Puncoviscana Formation; Cs= 4-50 ppm), which comprise clay and quartz-rich sandstones. The high values found in the pottery material are either related to weathered clay material used for pottery (which cannot be supported by the geochemistry) or the Puncoviscana Formation can be envisaged as the specific main source. Other Palaeozoic rocks are not enriched in Cs. If younger clay sources were used, then the Cs anomaly was recycled into post-Palaeozoic successions. Our results can suggest that the main used material was related to the Neoproterozoic Puncoviscana Formation and its derivates. For many samples high Ta and Cs concentrations are intriguing. Moreover, it seems that through time the same source material was used by the pottery producing cultures of the region.