Traces of Indigenous Buff Pottery Industry of Shahr-I Sokhta; Using Semi-Quantitative Analysis of Elements XRF

Shahr-I Sokhta is a historical settlement in south-eastern of Iran in the province of sistan-baluchestan, where the first settlement history goes back to 3200 BC. The results of excavations show four cultural-settlement period (I-IV) in this city that is divided into 11 phases. Period (II) goes back to 2500-2800 BC. The history of period (III) is equivalent to 2300-2500 BC, and history of period (IV) is suggested between 1750 and 1800 BC. This archaeological site is located 57 km from Zabol-Zahedan road. This site is registered as seventeenth heritage of Iran in UNESCO. One of the prominent features of this archaeological area is the existence of a lot of pottery shards on the surface of hills. Most of these pottery shards are buff color and have extensive domain from light buff to brick and greenish. Also, red and grey potteries have put in the next classification which the number of them is so little. Archaeological excavations carried out in this site pulled out thousands of pottery shards from the soil that are mostly buff-colored pastes. Also, among the pottery remnants of this 150 hectare site, clay pottery with red and gray paste have been seen. Archaeologists believe that most of the buff pottery shards are locally made. Hence, to determine whether this hypothesis is true, a scientific analysis was done to determine the chemical compositions of the pottery shards. In this paper, 15 pottery sample have been selected which all of them belong to settlement period II-III and goes back to 2200-2800 BC. The samples was tested using instrument analysis XRF to determine the major and trace elements of these potteries. The results analyzed using hierarchical cluster analysis (HCA) to specify pieces of pottery in two group local and nonnative. The results show that most of pottery is locating in a specific group with name of production group, where the samples no. 18259-9, 18265-10, 18266-13, 18273-4, 18271-15 are not locally made and located in another group. Based on the instrumental results, red and grey pottery are not related to Shahr-I Sokhta and probably these potteries are imported from another place.