At the Institute of Isotopes of the Hungarian Academy of Sciences, we operate a Prompt Gamma Activation Analysis facility, pla

Non-Destructive Prompt Gamma Activation Analysis of Chipped Stone Raw Material

Zsolt Kasztovszky

Institute of Isotopes, Chemical Research Centre

1121 Budapest, Konkoly Thege 29-33.

At the Institute of Isotopes of the Hungarian Academy of Sciences, we operate a Prompt Gamma Activation Analysis facility, planted on a horizontal cold neutron beam of the Budapest Research Reactor Since 1996. We perform archaeological applications of PGAA since 1998 at the Institute. Our co-operation with the Hungarian National Museum lasts since 2000, with the most important research of the ancient chipped stone tools and their raw materials. We have investigated various kinds of material from the Lithotheca collection and from the Prehistoric Collection of the Museum. In case of some rock types (such as obsidian and porphyry), we were able to provide direct provenance data for the archaeologists. In case of other rock types (such as various flints) we are still in the preliminary phase. We have studied 110 samples altogether, 76 of them were archaeological pieces, and the rest were geological references.

PGAA is based on the detection of characteristic gamma radiation, which is emitted following the capture of neutrons into the atomic nucleus. With the help of PGAA, it is possible to determine the concentration of major- and some trace elements, like B, S, Cl, Sc, V, Cr, Nd, Sm, Eu and Gd – depending on the sample. The unsurpassable advantage of PGAA that it gives the opportunity of non-destructive investigations of arbitrary objects.

According to our results, the grey flints belong to the most homogeneous group, considering the compositions. The archaeological objects are very similar to each other, and the most similar to the geological material from Prut and Volhynia. Porphyry and radiolarite as well as hornstone, which show very similar appearance, seem to form two distinct groups according to the major components of SiO₂, Al₂O₃ and K₂O. Obsidian is clearly distinguishable from other macroscopically similar glassy (either artificial) materials. Furthermore, we can differentiate between Carpathian and Mediterranean obsidian. Further subgrouping of Carpathian obsidian seems to be feasible.

References

Zs. Kasztovszky, K. T. Biró and V. Dobosi, Investigation of Grey Flint Samples with Prompt Gamma Activation Analysis, Proceedings of the 33rd Int. Symposium on Archaeometry, 22-26 April 2002 Amsterdam (Eds. H. Kars and E. Burke), Geoarcheological and Bioarchaeological Studies, Vol. 3, 2005, pp. 79-82

A. Markó, K. T. Biró, Zs. Kasztovszky: Szeletian felsitic porphyry: non-destructive analysis of a classical Paleolithic raw material, Acta Archaeologica Academiae Scientiarum Hung. 54 (2003) 297-314

Zs. Kasztovszky, K.T. Biró: Fingerprinting carpathian obsidians by pgaa: first results on geological and archaeological specimens, 34^th International Symposium on Archaeometry, Zaragoza, 2004.

Kasztovszky Zs., T. Biró K.: A kárpáti obszidiánok osztályozása prompt gamma aktivációs analízis segítségével: geológiai és régészeti mintákra vonatkozó első eredmények (in Hungarian), Archeometria Műhely, elektronic journal (http://www.ace.hu/am/) 2004, pp. 9-15.

Zs. Kasztovszky, K. T. Biró, A. Markó, V. Dobosi: Characterisation of high silica content chipped stone tool raw materials by cold neutron Prompt Gamma Activation Analysis, submitted to Archaeometry