Bronze composition of artifacts from the Ak-Dag I burial ground of the Scythian period in Tyva

Purpose. In 2011, the 2 nd archaeological team investigated a ritual ring and its mound layout during excavations of Ak-Dag burial in the River Eerbek Valley, the Republic of Tuva. The mound studied was a burial place of a male and female, who were buried in stone boxes. The metal burial items found in the mound were made of bronze; other items were made of bones and tusks of animals; there was also some turquoise jewelry. The analysis of the bronze objects had been published in a separate article. The authors dated the monument back to the 7-6 th centuries BC. Results. A variety of bronze objects which appeared in Scythian cultures of Siberia and Central Asia can be explained by increased level of metalworking and existing ties with the regions where tin was mined. This article aims at introducing our results of spectral analysis of bronze artifacts to scientific community. The metal objects found in the graves 1 and 3 count ten bronze items. For nine of them we have determined the composition of the metal. By their functional features, all the artifacts were divided into three groups, namely horse bridle, armaments and a jewelry belt. Out of them, eight objects were found in tomb 1 and one in grave 3. The spectral analysis was conducted at the department of Cenozoic geochronology of the Institute of Archaeology and Ethnography SB RAS using an electronic microscope Hitachi TM 3000 (Japan). The number of metals present in the alloys studied was not great. The alloys consisted of copper, tin, lead, zinc, arsenic and cadmium with copper as the basis of bronze alloy. Its content varied from 59.7 % to 92.2 % in different objects. The main metal in the alloy is tin, the concentration of which varies from 5.0 to 27.9 %. It is worth mentioning that samples 6 and 7 had more than 27 % of tin. Arsenic was detected in 4 samples in the amount of less than 2 %. An exception is sample 5 with tin content of 15.3 %; 10.3 % arsenic in it can be attributed to the fact that the alloy of the cast belt belonged to the category of ternary alloys. Conclusion. Previous studies of the spectral composition of bronze artifacts showed that in early Scythian culture the main type of alloy was arsenical copper. In the post-Arzhanskoe time, overwhelming majority of the objects analyzed was made of tin bronze. As for dates, the chronological transition boundary was the period of 7-6 th centuries BC. It is attributed to the existence of Aldy-Bielsko stage of Scythian culture. The end of the 6 th and the 5 th centuries BC witnessed a transition to using arsenical copper which was the material for typical products of Saglynskogo stage of Scythian culture.