خلاصة:
گچ از قدیمیترین موادی است که از حدود 14 هزار سال پیش تاکنون، در ایران مورداستفاده بوده است.کاربرد فراوان گچ در ساخت و تزئین بناها و تولید مصنوعات مختلف،یکی از ویژگیهای بارز معماری دورۀ ساسانی است. باوجود شناسایی شواهد زیادی از کاربرد گچ در ادوار مختلف و پژوهشهای گسترده دربارۀ گچبریهای ساسانی، هیچگونه شواهد علمی و باستانشناختی از واحدهای کارگاهی مربوط به پخت و فرآوری گچ تا سال 1393 ه.ش. گزارش نشده است. در بهار سال 1393 از کاوش محوطۀ ساسانی برزقواله لرستان، یک واحد کارگاهی کشف و شواهد نشان از کارکرد آن بهعنوان کورهای جهت پخت گچ بوده است. اهمیت این یافته بهعنوان نخستین نمونۀ شناخته شده از این گونۀ کارگاهی در ایران و دورۀ ساسانی سبب شد تا در نوشتار حاضر به آن پرداخته شود. هدف اصلی پژوهش حاضر، تشریح روند کشف و معرفی کارگاه، جهت آگاهی پژوهشگران و جبران بخشی از نبود اطلاعات درخصوص این نوع کارگاهها است. مهمترین پرسشهای پژوهش این بود که: 1- کارگاههای پخت گچ محوطۀ برزقواله در چه نقاطی برپا شده؟ 2- چه متغیرهایی در انتخاب مکان و فرم ساخت آنها مؤثر بوده؟ 3- با چه طرح و نقشهای و شامل چه اجزایی هستند؟ فرضیات پیشِرو این بود که با توجه بهشرایط محیطی و سازند گچی آن در قسمت شمالی و شمالغربی شهر، احتمال داده شد کارگاههای پخت گچ در این بخشها باشد.متغیرهایی چون: فراوانی، سهولت دسترسی و نزدیکی معادن به شهر، جریان دائم آب، وجود تراسهای میاندرهای، سوخت کافی، وزش جریان باد در درهها، در انتخاب مکان ساخت مؤثر بوده است. نقشۀ ساخت آنها احتمالاً مدور یا چندوجهی و دارای آتشخانه، هواکش، و محل بارگذاری مادۀ خام میباشند. پژوهش حاضر به روش توصیفی-تحلیلی بوده و مبنای آن بر نتایج حاصل از بررسی ها،کاوشهای باستانشناختی و مطالعات نظری گذارده شده است.
Gypsum is one of the oldest materials that has been used in Iran from about 14,000 years ago until today. In the Sassanid era, the extensive use of gypsum in the construction and decoration of buildings and the production of various artifacts is a prominent feature. Despite the great evidence of the use of gypsum in different periods and extensive research on Sassanid tore, no scientific and archaeological evidence has been reported from the workshop units related to gypsum baking and processing until 1393 AH. In the spring of 2014, from the excavation of the Sassanid site of Barzqualeh in Lorestan, a workshop unit was discovered, and evidence showed its function as a kiln for baking gypsum. The importance of this finding as the first known example of such a workshop in Iran and the Sassanid era caused it to be addressed in this article. The main purpose of this study is to describe the process of discovery and introduction of the workshop, inform researchers, and compensate for the lack of information about this type of workshop. The most important research questions include: 1- Where are the gypsum baking workshops set up in the Barzqualeh area? 2- What variables were effective in choosing the place and form of their construction? 3- What patterns and components are included? The hypotheses were that due to the environmental conditions and its gypsum formation in the northern and northwestern parts of the city, it was possible that there were gypsum baking workshops in these parts. Variables such as frequency, ease of access, and proximity of mines to the city, constant water flow, the presence of inter-valley terraces, sufficient fuel, wind flow in the valleys were effective in choosing the construction site. Their construction plan is probably circular or multifaceted and has a firebox, ventilator, and raw material loading site. The present study is a descriptive-analytical method and is based on the results of archaeological surveys and theoretical studies.Keywords: Lorestan, Barzqualeh, Gypsum Kiln, Sassanid, Architecture.IntroductionGypsum is one of the materials that has been popular in the architecture of different periods of Iran due to its abundance, easy access, cheap extraction and high ductility. The oldest evidence of the use of gypsum in Iran, about 14 thousand years ago, has been obtained from the excavations of Choghaglan hill in Ilam. The peak of gypsum use in Iran is from the Parthian period onwards, especially the،Sassanid period. The،Sassanid used gypsum as a mortar in the erection of building components and elements, a coating for surfaces and a method for decorating and arranging buildings. Despite the widespread use of gypsum, so far no examples of workshops related to gypsum baking and processing in،Sassanid areas or before and after it haven’t been reported before the compilation of this article. The only place that has evidence of this issue is the city of Barzqualeh belonging to the،Sassanid era in the west of the country and south of the Central Zagros region in Lorestan province, in the basin of Seymareh dam, during archaeological rescue excavations in 1393 AH, a perfect example of a gypsum kiln was discovered. The present study is based on explaining how to discover and introduce the discovered furnace from the excavation of Barzqualeh site in order to compensate for the lack of information about this type of industrial workshops. This research is a descriptive-analytical method, relying on surveys, field excavations and library studies to answer questions such as: gypsum baking workshop units required by the residents of Barzqualeh, which were used in the construction of most of the architectural spaces of the gypsum, where? What was their architectural structure like? Considering the environmental conditions and the abundance of gypsum mines in the northern parts of Barzqualeh, it was possible that along the valleys located in this part, it would be possible to identify gypsum firing workshop units and their architectural structure. In this connection, a point on the eastern slope of Farash Valley was selected and named Trench No. 3. Exploration of this trench led to the discovery of a gypsum kiln. According to the excavations and the certainty of the history of Barzqualeh as a city from the،Sassanid period, and the evidence obtained from the discovered furnace, its attribution to the, Sassanid period is definite. Exploration DescriptionExcavation in Trench 3 led to the discovery of circular instruments with a diameter of 5 meters with industrial application and kilns for firing gypsum, with a surrounding wall stone thickness of 55 cm and an average height of 1.5 meters with mud mortar and internal lining. It is made of flowers. The structure has an entrance from the southwest and temperature control valves in the northeast, which are installed towards the prevailing wind of the region. In the center of the structure, the clay arms are crescent-shaped on the floor and on them, another arm is installed horizontally for strength, and below these arms, there is a kiln firebox and triple arms in the east and west of the furnace. The outer part of the eastern part of the kiln was full of gypsum related to the kiln activity. Two architectural periods were identified in the kiln. The first or older period consists of 16 layers and two phases. In the first phase, the arms of the east and west sections and valves and stone pits were used. The presence of debris indicates that the furnace was abandoned in this phase after use. The architectural evidence of the second phase is the arms of the central and eastern parts, the fire house, the temperature control valve and the gypsum depots in the eastern part of the furnace. Due to the arrangement of gypsum stones parallel to the crescent arms and the remains of the firebox ash, it seems that in this phase, the furnace was left unused. The second or newer period includes long periods from the time the furnace was abandoned to the present day, and includes 4 layers. The second layer has several pieces of pottery. The pottery from Layer 4 is a typical example that belongs to the Sassanid period in comparison with the pottery obtained from other excavations. According to the abundant evidence of Sassanid works in Barzqualeh, it is possible to attribute the discovery of Trench 3 to the Sassanid era. ConclusionThe present article sought to introduce Barzqualeh gypsum baking industrial workshop and explain the process of its discovery. The residents of Barzqualeh, with full knowledge of the environmental landscape and careful study, have chosen a suitable place to carry out their industrial activities. The architectural structure of the furnace and the correct arrangement of its elements and components by the craftsmen show their accuracy in using natural forces. The opening of the furnace is located in the southwestern part and the vents related to the ventilation or exhalation flow are located in the northeastern part. The size of the loaded raw materials indicates that they are harvested in a suitable and portable size, so that in addition to being easy to transport, they can be cooked faster. To save time and money, the workshop has been set up in a place that has easy access to the surrounding gypsum mines. Considering that this workshop is the first known example of gypsum kilns in Iran and neighboring regions, it may be possible to speak with more confidence about the production process and operation of the most widely used building and decorative materials of the Sassanid era. And by studying it more closely, in future researches of Sassanid era sites, similar examples can be searched more carefully.