2007 International Nuclear Atlantic Conference - INAC 2007 Santos, SP, Brazil, September 30 to October 5, 2007 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-02-1 THE UTILIZATION OF TRACE CHEMICAL COMPOSITION TO CORRELATE CERAMICS WITH CLAY DEPOSITS Kelly P. Nunes 1 , Rosimeiri G. Toyota 1 , Casimiro S. Munita 1 , Paulo M. S. Oliveira 1 , Eduardo G. Neves 2 , and Emílio A. A. Soares 3 1 Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN – SP) Av. Prof. Lineu Prestes, 2242 05508-000 São Paulo, SP kpnunes@yahoo.com.br camunita@ipen.br 2 Museu de Arqueologia e Etnologia, Universidade de São Paulo, USP Av. Prof. Almeida Prado, 1466 05508-900 São Paulo, SP edgneves@usp.br 3 Departamento de Geociências, Universidade Federal do Amazonas, AM Rua Desembargador Rodrigo Otávio Jordão Ramos, 3000 69007-000 Manaus, AM easoares@usp.br ABSTRACT In this work, 22 clay samples near Hatahara and Açutuba 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 of 8,92x10 12 cm -2 s -1 during one hour. The elementary concentration results were studied using multivariate statistical methods. The compositions group classification was done through cluster analysis and the similarity/dissimilarity among the samples was studied by means of discriminant analysis. 1. INTRODUCTION The archaeological sites Hatahara and Açutuba, localized in the merning of Negro and Solimões 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 dissimilarities 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 clay deposits. The