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Afshari S, Niakan L, Omrani B. (2025). Petrographic Analysis of the Pottery (Ilkhanid Period) Sham Valley on the Banks of the Aras River. Parseh J. Archaeol. Stud.. 9(32), 317-340. doi:10.61882/PJAS.435
URL: http://journal.richt.ir/mbp/article-1-435-en.html

Abstract
An archaeological survey was carried out in 2019 with the aim of identifying and investigating the Ilkhanate period on the banks of the Aras River in East Azerbaijan province. The present study focused on the study of the large, wide, mountainous and impassable gates called “Sham Valley”, which was formed by the confluence of two major rivers of the Aras with Aqchay, which extends near the city of Khoy and was important in the field of trade relations and culture. The strategic and geopolitical position of the region with the surrounding regions such as the Caucasus, Turkey and Central Asia, as well as its geoeconomic position as a corridor of communication corridors led to many cultures and civilizations from the second millennium BC to later epochs. Alternating in this area. In other words, the main factor for the emergence of these ancient settlements is the location of the trade routes, the easy inter-regional and supra-regional communication, especially during the Mongolian Ilkhanate period, which played an important role in the development of cultures in the Sham valley. On the other hand, due to the religious importance of this region during the Mongolian Ilkhanate period, based on its foreign policy and the existence of important churches such as the church of Saint Stepanos Monastery, the Qarah Church and Zur Zur Church, which are known in the world and in whose case there are no reports or documents, there is no archaeological activity; therefore, a careful study of this area, as well as the study of the ceramics obtained from these areas, has provided useful information about pottery technology and the social structure of the area in different cultural periods, especially the Ilkhanate period.
Keywords: Northwest Iran, Jolfa, Sham Valley, Ilkhanid Pottery, Petrography.

Introduction
As a result of the study, 53 ancient sites from prehistory to Islamic times have been identified and recorded; areas such as the Naneh Maryam Cemetery and the Chupan Church are the most important. In these areas a significant number of Middle Islamic centuries ceramic pieces were carved in simple glazed form. It is important to identify the constituents of each pottery, to determine the difference in composition and constituents between the samples, to determine the percentage of each constituent, to determine the baking temperature of the pottery based on the available minerals, and finally to archaeologically study its origin and understand the social structure of the area. Knowledge of the pottery’s components can provide us with useful information about the geographical origin of pottery in the region and its consumers.

Materials and Methods
Thin-section petrography is one of the common and widely used methods in geology and archaeology. This method is employed to examine a broad range of materials such as rocks, minerals, ceramics, slag, bricks, and plaster (a mixture of lime and gypsum). In this technique, an extremely thin section of the rock or ceramic object under study is prepared. This section is thin enough to allow light to pass through it. Then, by placing it under a polarizing microscope, the minerals present can be analyzed. Since minerals exhibit different properties and colors under polarized light, petrography specialists can distinguish them from one another; thus, it is possible to identify the types of minerals, their characteristics, shapes, and sizes in rock or ceramic samples (Ellis, 2000). Moreover, ceramic petrography provides valuable information regarding the technical characteristics of ceramics, such as whether the vessels are wheel-thrown or handmade, and the additives incorporated into the ceramic paste (temper). These tempering materials typically include fragments of igneous rocks, siliceous particles, and silt and clay components. All plant-based and organic materials in ceramics are eliminated at temperatures of approximately 200 to 250 degrees Celsius, leaving only their voids behind (Mousavi-Faghih, 2018).
For the microscopic studies of ceramics obtained from the Sham valley survey, a James Swift model polarizing binocular microscope was used. The magnification applied in this study was 4X. To facilitate the presentation and analysis of results, the petrographic data were organized in a table. The first row of the table lists the components constituting the ceramics, and the first column provides the name and number of each ceramic sample separately. The presence of each component or mineral in the sample is indicated by an asterisk (*), while its absence is marked by a dash (–). If the abundance is minor or trace, it is denoted by (tr). The selected samples for this study come from two sites: the Naneh Maryam cemetery area (code C.042) and the Chopan Church area (code C.053). Ceramics consist of two main parts: the paste (matrix) and the tempering materials. In ceramic petrography studies, a significant focus is given to the additives mixed into the paste. Archaeologists typically consider components larger than 0.1 millimeters as temper or inclusions. In the study of ceramic samples from the Darreh Sham sites, the petrographic method was employed to identify the components and compositions present in the ceramic paste.

Conclusion
Since the Sham Valley in northwestern Iran has been considered on the basis of texts and travelogues since the early Ilkhanate period, there is a need to inform the patriarchs about the use of pottery from the Middle Islamic period and its production. Accordingly, petrographic studies were carried out on 12 pieces of pottery from the two sites of the Neneh Maryam cemetery and the Chupan church to determine the place of production of these ceramics. On the basis of the available samples and on the basis of the analyses carried out, it was found that the composition of all the pottery studied was related to the Jolfa area and the river sediments and alluvial deposits of the Aras river, as well as seasonal and local rivers. With regard to the baking temperature of the pottery, with the exception of the site of the Shepherd Church, where all the potteries studied had no calcite and tolerated temperatures above 800 degrees Celsius, potteries from other areas tolerated temperatures below or close to 800 degrees Celsius. Two categories of inclusion or temper are observed in the composition of the paste. One technique was used in the production of all glazed ceramics. In this way, a layer of glaze can be seen on the outer surface of the sample and, depending on the desired color, a layer of metal oxide can be found underneath. Underneath the glaze layer is a porcelain layer (a mixture of fine-grained quartz and white clay), which lies directly on the clay body. Furthermore, based on the composition and petro fabric of the examined ceramic samples from this area, it can be concluded that the ceramics are almost identical and similar in composition and origin.