Characterization of Tyre pottery production using PIXE and XRF techniques and cluster analysis -

Abstract

Ceramics are the most abundant archaeological objects and therefore they are the most studied by archaeologists nowadays, since they are characteristic of ancient civilizations and, thus, several related information could be revealed. Ion beam analysis techniques, such as proton induced X-ray emission PIXE, have been proved to be effective tool to characterize chemically the elemental composition of such archaeological objects, in order to determine their provenance and identify possible sites of production. Since few years, a program was started at the Lebanese Accelerator, using PIXE technique, concerning the characterization of archaeological ceramic products from the Lebanese coast. This time, it is proposed to study the excavated ceramics from Tyre, the prestigious city of antiquity (locally named Sour and located at 85 km south of Beirut). The originality of Tyre in this context is its long permanence of prosperity as a great center of production and trade through the centuries without interruptions, which were experienced by neighboring cities and rivals. At Tyre, the production of ceramics occurred since antiquity till medieval periods (IV B.C. till XIII A.D.). In this work, several series of excavated pottery are analyzed in order to characterize the Tyre production, based on the elemental composition, and thus to be distinguished from those of other neighboring workshops (Serapta, Sidon or Acre), possible sites of ceramic production at this period. Proton Induced X-ray Emission technique (PIXE) is used to determine the elemental composition of the studied excavated shreds. A proton beam of 3MeV and a funny filter of Aluminum, used as X-ray absorber, allowed the detection of almost 20 elements in one spectrum (Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Ba and Pb). However, only 12 elements were used in a multivariate statistical program to identify and classify into groups, according to their provenance, the studied objects.