Achaeometrical Research in Hungary II., 1988

ANALYSES - METALS - Géza SZABÓ: Evaluation of late Bronze Age Carpathian tinbronzes based on the alloying content

The results reported above show that the study of archaeological bronze finds revealed significant differences in the material composition, depending on processing, on the applied methods and also on the origin of the particular samples. Plotting the graphs of composition measured on the surfaces and cut polished surfaces of articles from Regöly-Veravár find it can be clearly seen that the data measured at various places differ considerably. High enrichment of some alloying materials on the surface is particularly striking./Figure 4./ Replacing the normal practice of metallurgical investigations and observations with optical microscope tests of not only the cut surfaces but also of the surface itself, the alloying material, the tin. segregated on the surface, can be observed visually and unambiguously distinguished (Figure 1-2). These data offer an explanation to the extremely high tin concentrations detected on the surface with X-ray spectrometry down to depth of 0.1 mm (Figure 6-7). As it was demonstrated by studying the polished surface of wire spiral (SZABÓ: 1993 No. 130) and SEM analyses at various places, thickness of tin aggregates is considerable, and using the methodology described above, or a similar one. the results of analyses of archaeological objects could be distorted./Figure A.I Evaluating the results of his studies L. Költő also remarked, that the figures did not allow any classification either for a territorial distribution or for article types.

(KÖLTŐ 1996 83) Only a group of higher tin content and another one with lower tin content could be distinguished.(KÖLTŐ-KIS VARGA: 1992 81) From one point of view this observation is in accordance with metallurgical pictures of the surfaces of archaeological objects and also with measured results: data demonstrate the tin segregation to be in relation with the heat treatment of articles. On the articles which are simply cast, tin segregation could not be observed. Relying on the above described facts, conclusions drawn from the cluster analyses using mere data of X-ray emission methodology could not be taken as substantiated and acceptable (KÖLTŐ-KIS VARGA 1992 84; HONTI 1992 46). Due to the delimitations of the methodology. X-ray emission methods can be used also in the archaeological research only for fast, orientating analyses, like all composition measurements which, for avoiding destruction, study only the surface or use several grams of samples from a near-surface layer. Therefore, in what follows, for evaluation of archaeological finds the old data from conventional measurements and the new. variously controlled data shall be used (Figure 8). Our objective is that, after the necessary filtration of data and repeated evaluation, we would try to outline the raw material circulation of the Late Bronze Age along with dividing the main products into groups according to place of their manufacturing and their application as well. Conclusions In the recent thorough metallurgical studies we succeeded in observing and reconstructing the processes used to change the material structure of articles in the Late Bronze Age. Due to new studies and methods different from those used earlier, the segregation of alloying material on the surface of annealed objects could be demonstrated, which gives an explanation to the consequently appearing high tin content measured since 1950 with the frequent use of X-ray emission method. These measurements showed, particularly for Hungarian Late Bronze Age articles such a high tin content that from the aspect of alloying material, and spuriously the idea was getting recognised about a find group of Carpathian Basin separate of European ones. 162