Classification of archaeologically stratified pumice by INAA

In the framework of the research program "Synchronization of Civilizations in the Eastern Mediterranean Region in the 2nd Millenium B.C." instrumental neutron activation analysis (INAA) was used to determine 30 elements in pu mice from archaeological excavations to reveal their specific volcanic orig in. The widespread pumiceous products of several eruptions in the Aegean re gion were used as abrasive tools and were therefore popular trade objects. A remarkable quantity of pumice and pumiceous tephra (several km(3)) was pr oduced by the "Minoan eruption" of Thera (Santorini), which is assumed to h ave happened between 1450 and 1650 B.C. Thus the discovery of the primary f allout of "Minoan" tephra in archaeologically stratified locations can be u sed as a relative time mark. Additionally; pumice lumps used as abrasive ca n serve for dating by first appearance. Essential to an identification of t he primary volcanic source is the knowledge that pumices from the Aegean re gion can easily be distinguished by their trace element distribution patter ns, as previous work has shown. The elements Al, Ba, Ca, Ce, Co, Cr, Cs, Dy , Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta Tb, Th, Ti, U, V, Y b, Zn and Zr were determined in 16 samples of pumice lumps from excavations in Tell-el-Dab'a and Tell-el-Herr (Egypt). Two irradiation cycles and five measurement runs were applied. A reliable identification of the samples is achieved by comparing these results to the database compiled in previous s tudies.