Archaeometry and Archaeology: preliminary studies of the ceramics from archaeological sites of the upper Madeira river/Rondônia - Brazil.

Angislaine Freitas Costa,Renato Kipnis,Casimiro Sepúlveda Munita,Silvana Zuse

doi:10.15392/bjrs.v9i1a.1424

Abstract

In southwest Amazonia, in the region of the Upper Madeira River, Rondônia, archaeological research has shown that communities with diverse cultures co-existed in the pre-colonial past (ca. 1,000 BP). Archaeological sites from this period located on river banks and islands consist of large extensions of ceramic deposits which reflect different daily activities and social positions that existed within these groups. The complexity of these societies is attested to by the diversity of both ceramic forms and iconography. In this work, 140 ceramic fragments from eight archaeological sites were studied by means of instrumental neutron activation analysis (INAA) to determine Na, K, La, Sm, Yb, Lu, U, Sc, Cr, Fe, Co, Zn, Rb, Cs, Ce, Eu, Hf, Ta and Th mass fractions, with the purpose of classifying and ordering artifacts which are related to one another in their chemical compositions. The analytical method used is adequate for this type of study because it is a semi-destructive technique with high sensitivity and precision that can determine chemical elements in trace and ultra-trace levels, essential for studying small variations in elemental concentrations. Multivariate statistical analyses were used to evaluate the dataset. Initially the mass fractions were normalized to compensate for the large difference in magnitude among elements determined in percentage and in trace level. Subsequently, the mass fraction data were interpreted through cluster analysis, discriminant analysis and a log-log scatterplot. The results show the existence of four compositional groups, indicating different clay sources.

Highlights

Pottery is the most abundant material evidence of human activities in the past, which has been found in many different archaeological sites in the world [1]
Archaeometry has contributed, through the use of the technique of instrumental neutrons activation analysis (INAA). This analytical method is suitable because it is a semidestructive technique that can determine several chemical elements simultaneously, with high sensitivity, precision and accuracy [4, 5, 6] thereby providing the characterization of the elemental chemical composition of different clays found in archaeological ceramics [7, 8, 9, 10, 11, 12, 13, 14]
The elementary concentrations of each were normalized by the transformed log10, which is a common procedure in archaeometric studies, whose function is to compensate for the large differences in magnitude between elements that are at higher level and those at trace level [11]

Summary

Introduction

Pottery is the most abundant material evidence of human activities in the past, which has been found in many different archaeological sites in the world [1]. The analysis of the ceramic is made in a macro manner (presence of decoration, marks of use, color and shapes) and microscopic (use of binocular magnifying glass to identify types of antiplastics, classified by the inclusion of minerals and organic elements such as tree bark and freshwater sponge), making it possible to characterize the technologies and define cultural traditions [3]. This type of study is insufficient to identify the choice of raw materials and their source (clay source). This analytical method is suitable because it is a semidestructive technique that can determine several chemical elements simultaneously, with high sensitivity, precision and accuracy [4, 5, 6] thereby providing the characterization of the elemental chemical composition of different clays found in archaeological ceramics [7, 8, 9, 10, 11, 12, 13, 14]

Objectives

Methods

Results

Conclusion