THE UTILIZATION OF TRACE CHEMICAL COMPOSITION TO CORRELATE CERAMICS WITH CLAY DEPOSITS

In this work, 22 clay samples near Hatahara and Acutuba archaeological sites, and 135 ceramic samples were analyzed by means of Instrumental Neutron Activation Analysis. INAA is the most suitable technique because it does not require mineralization of samples and has high sensitivity, accuracy and precision. The samples were irradiated in IEA-R1 reactor at IPEN-CNEN-SP at thermal neutron flux o f 8,92x10 12 cm -2 s -1 during o ne hour. The e lementary concentration results were studied u sing multivariate statistical methods. The c ompositions group classification was done through cluster analysis and the similarity/dissimilarity among the samples was studied by means of discriminant analysis. The archaeological sites Hatahara and Acutuba, localized in the merning of Negro and Solimoes rivers, Central Amazon, have in all their extension a large quantity of ceramic material. In archaeometry, the classification and identification of these objects by means of physics and chemical techniques, allow understand the origin of the raw material used in the manufacture of these artefacts. The ceramics are formed by sedimentary rocks, whose main component is clay. Clay is a material made of aluminum silicates of indefinite composition. The main components of the clay are AlO3 and SiO2, which represent in quantities larger than 10%. Smaller impurities such as Na, Mg oxides are found in concentrations, which vary from 0.1% to 5%. However, trace elements whose presences in clay are accidental are the ones that provide the best information for provenance studies. Ceramics can be grouped according to similarities and d issimilarities derived from the chemical composition data. By means of determination of chemical composition ceramic and clay, is possible correlate date both of them, to recommending if the ceramic is or not belong of the place where was found. The group differentiation depends on the discriminant element concentration, which will indicate the existence or not of one or more c lay deposits. The