COMPOSITIONAL GROUPINGS OF SOME ANCIENT NATIVE POTTERY MADE IN MARAJÓ ISLAND

In this work 161 Marajoara ceramics fragments were studied by means of the Instrumental Neutron Activation Analysis (INAA) to determine As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb, and Zn concentrations with the purpose to classify and to order the ceramics which are related to one another in their chemical compositions. The analytical method is right for this type of study because it is a nondestructive technique, however, the sample procedure is destructive, besides being highly sensitivity, accuracy and precision to determine chemical elements in trace and ultra trace levels. To study the data set multivariate statistical analysis techniques were used. Initially the c oncentrations were normalized using log base 10. Following the outliers were studied by means of Mahalanobis distance. Finally the data were interpreted b y means of components analysis and discriminant analysis.