نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانش‌آموخته کارشناسی‌ارشد باستان‌شناسی، گروه باستان‌شناسی، دانشکدۀ ادبیات و علوم انسانی، دانشگاه شهرکرد، شهرکرد، ایران
2 دانشیار گروه باستان‌شناسی، دانشکدۀ ادبیات و علوم انسانی، دانشگاه شهرکرد، شهرکرد، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract
Due to the limited number of archaeological studies conducted on the Parthian Period, it is imperative to design petrographic and mineralogical studies on the coarse black ceramics from that era. The objective of this study is to determine the manufacturing techniques of the potsherds and ascertain whether they were produced domestically or imported to Qeshm island. This research is a descriptive, analytical, and adaptive study aimed at addressing the following inquiries: What are the distinguishing characteristics of these potteries? What elements constitute the coarse black ware and how do they relate to the geological structure of Qeshm? What are the similarities and differences between the ceramics of Qeshm and its neighboring regions? To achieve these objectives, twelve pottery fragments retrieved from three Parthian sites, namely Defari (QS 6), Gorbedan (QS 72), and LenjSazi 3 (QS 132), were sampled and examined using polarized microscopy. The results revealed that the Parthian potteries from Qeshm exhibit structural similarities with those from Makran and other locations along the southern coasts of the Persian Gulf (UAE, Bahrain, and Oman). Furthermore, it was observed that the original paste of Qeshm’s potteries is consistent, suggesting that the raw materials were procured locally from the island and not imported.
Keywords: Parthian Period, Persian Gulf, Coarse Black Ware, Petrography.
Introduction
Qeshm, the largest island in the Persian Gulf, did not undergo urbanization during the Parthian era. It was heavily influenced culturally by the southeast of Iran during that time. Parthian sites on Qeshm Island could be categorized into backshore sites, coastal sites, and cemetery sites. One of the significant types of Parthian pottery recovered from Qeshm is the coarse black ware, typically with black or dark gray paste, mainly sourced from the Defari area. This type of pottery has been discovered in various parts of southern and southwestern Iran, as well as in locations such as Abu Dhabi, ed-Dur, Bahrain, Meliha, and Diba. A comprehensive analysis conducted by Iranian researchers involved the examination of 889 potsherds dating back to the Parthian Period. The findings of this study revealed a strong cultural and economic bond between the Makran district and its neighboring regions, including Hormozgan Province and present-day Pakistan. Notably, the research concluded that South Makran emerged as the primary hub for pottery production during the Parthian era.
Conventional laboratory techniques enable the examination of the composition, structure, and origins of ancient pottery. Petrography, a widely employed method in geological science, is utilized by archaeologists to analyze cultural materials such as stone objects, and ancient ceramics. This technique involves observing the thin sections of the rocks and potsherds under the polarized microscope and interpreting the constituent minerals and particles.
Twelve potsherds, unearthed during archaeological excavations at the Parthian sites on Qeshm Island, underwent petrographic analysis. The primary inquiries included: 1- What are the mineralogical properties of Qeshm’s coarse black pottery? 2- How do the minerals recorded in the potsherds compare to each other? 3- What was the range of firing temperature and how was the quality of pottery production at that time?
Article text
Most pottery items exhibited a dark gray and brownish gray hue, possibly attributed to the reduction conditions experienced during the firing process and insufficient oxygenation. When exposed to an ample supply of oxygen, the clay undergoes proper oxidation at temperatures around 900 degrees, resulting in a well-oxidized appearance. However, in the absence of adequate oxygen, carbon remains trapped within the clay, causing it to adopt a brown or black coloration.
In the present study, a total of 12 potsherds were sampled from three Parthian sites (Defari, Gorbedan, and LenjSazi 3) and were analyzed. The thin sections of these samples were meticulously examined using polarized microscopy. The results revealed that among the pottery samples, only one (QS 6-2) contained sandstone, while another sample (QS 6-3) contained anchorite. Additionally, a sample (QS 6-4) obtained from the Defari area exhibited the presence of a radiolarian fossil.
The findings indicated that all cases exhibited a porphyry structure, with void space also being present in all instances. Grog, calcite, sparite, and micrite fragments were found in 75%, 83.33%, and 41.66% of the pottery samples, respectively. Quartz, hematite, plagioclase, and periclase were identified in 91.66%, 75%, 50%, and 75% of the cases, respectively. Qeshm Island is situated in the Zagros fold zone geologically, hence the occurrence of carbonate and sandstone sedimentary units in the pottery is not surprising. Most of the filling materials in the pieces have origins in igneous and sedimentary sources. The firing temperature of the pottery is estimated to be between 900 and 1100 °C, as most were dark gray in color, and some contained periclase. The potsherds generally displayed a hard or semi-hard structure without cracks, indicating firing temperatures above 1000 °C, absence of CaO, and the presence of calcium, magnesium, iron silicates, and aluminosilicates minerals.
Within the pottery samples, only one instance (QS 6-2) contained sandstone, another instance (QS 6-3) contained anchorite, and a third instance (QS 6-4) from the Defari region contained a radiolarian fossil. The petrofabric analysis verified the existence of 58.33% plagioclase feldspar. When the temperature exceeds 700 °C, free lime (CaO) can react with free silica (quartz) and aluminum, resulting in the formation of gehlenite (Ca2Al2Sio2). Additionally, wollastonite (CaSiO3) is produced through the combination of calcite (CaCo3) and silica (quartz). In the absence of quartz, the primary core of gehlenite and wollastonite is established at temperatures between 800 and 900 °C and will remain stable up to 1100 °C. These two components are classified as intermediate elements and in the presence of quartz, they transform into anorthite (CaAl2Si2O8).
Conclusion
The firing temperature range for the potteries is estimated to be between 900 and 1100 °C. The dark gray color and the presence of periclase mineral in some of the samples suggest exposure to temperatures higher than 900 °C, with firing continuing under reduced conditions. Sample 1, with an orange color, stands out due to its different appearance, indicating oxidation conditions during firing in the range of 600-700 °C. Samples 2, 3, 4, 6, and 12, in red-gray or brown color, show signs of both oxidation and reduction conditions during firing. The majority of the potsherds exhibit a hard or semi-hard structure without cracks, suggesting firing temperatures above 1000 °C, the absence of CaO, and the presence of calcium, magnesium, iron silicates, and aluminosilicates minerals. Petrographic investigation reveals structural similarities between the Qeshm’s Parthian potteries and those found in Makran, as well as other archaeological sites along the southern coasts of the Persian Gulf (UAE, Bahrain, and Oman). The original sediment (paste) composition of the Qeshm potteries also appears to be consistent across samples, indicating that these Parthian ceramics were produced locally.
کلیدواژه‌ها [English]
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