The Petrography and XRF Analysis of Bakun Pottery Assemblage at Tal-e Mash Karim, Semirom District

Experimental studies to analysis of Iranian prehistoric pottery lead to our more detailed knowledge about its production and distribution. Among these, pottery related to Bakun period during fifth millennium B.C. on the Geographic region of Southern Zagros and Fars province is an important phenomenon to understand the expansion of culture in the Kur River Basin at Central Fars and its dispersal to Northern borderlands on the Semirom district. Typically, this pottery is painted and has buff color paste, which it seems that made with high skill on the complex developed kilns. These wares are quite consistent with clean paste and no visible inclusions, painted in colors ranging from dark red through brown to black in a complex variety of patterns on a smooth surface. Many sherds are slightly green with shiny black paint as a result of over firing. Forms include a range of open ring based or flat based bowls, conical and straight sided beakers, and a variety of pots and storage jars. Based on the importance of materials, we selected 10 pottery sherds from the excavated archaeological site of Tal-e Mash Karim to experimental analysis. Tal-e Mash Karim is located at the Semirom district, Southern Esfahan province, generally linked to archaeological cultures of Fars region. As a result, by the analysis we are going to find pottery making’s technology of early societies on the one of small intermountain valleys of Zagros during the Middle Bakun (Gap) period (around 4600-4300 B.C.). Tal-e Mash Karim is a small mound, covering an area of c. 0.5 ha and rises to a height of c. 2 m from the surrounding land and situated at the altitude of 2360 m above sea level on a highland plain. The excavation was conducted in 2014, involving investigations of three trenches, called A and B, each measuring 5×5 m., comprised the main excavation area of the central part of the mound, while Trench C (2 × 1 m), was opened to test the stratigraphic sequence of A and B. The experiments include two methods (1) Petrography analysis and (2) X-Ray Florescence (XRF) analysis that is delivered to laboratory of Research Center for Conservation of Cultural Relicts (RCCCR). Based on Petrography and also geological studies at Semirom district it could be said that the pottery assemblage of Tal-e Mash Karim has a type of internal and local production that has been assigned to people of these settlement or other sites of this region where is produced the Bakun vessels. Beside the collected painted fine sherds, there are some coarse plain samples with two colors horizontal sections. All samples have greatly blank voids, which are included numerous organic inclusions on the external side of sherd as temper. There are two textures of silty and porphyry. Except the samples of 7 and 8, the results show that the all samples haven’t firing temperature more than 800 C°. Geological Studies at the Semirom district shows that the sediments and altitudes of this region have the Calcite mineral elements which are visible in the pottery composition. In the samples of 4 and 7, the type of Calcite is Dolomite, which has been eliminated by heat. Thus, dominant phenomenon on the samples is composition of Hydroxide Calcium and Secondary Calcite mineral composition. Based on the XRF analysis, the composition of Calcite mineral elements on the pottery show the lowest amount of Oxide Calcium in samples 8 and 9, while highest amount is occurred in the samples of 10 and 11 that these completely match to Petrography results. The comparison of XRF results of Tal-e Mash Karim with Tappeh RahmatAbad’s XRF Analysis on the 26 Bakun sherds show that their internal production is accompanied with 950 C° to 1050 C° firing temperature. Consequently, the samples of Tal-e Mash Karim fired at lower amount than Rahmat Abad.