فن‌آوری تولید و آنالیز سفال عصر مس و سنگ جدید شمال غرب ایران براساس آزمایشات xrf/ xrd و پتروگرافی(مطالعه موردی تپه گردآشوان)

تپه گِردآشوان در حاشیه‌‌ی شرقی دشت پیرانشهر، در شیب دامنه غربی ارتفاعات شرقی دشت و رودخانه لاوین واقع شده است. تپه گِردآشوان پشته‌‌ای حدود 2750 مترمربع را در بر می‌‌گیرد. در این تپه استقراری طولانی مدت شکل گرفته و دارای هشت متر انباشت فرهنگی با چهار فاز معماری و سفال شاخص گونه پیزدلی lc1 و کاهرو lc2/3 است. مطالعه مواد فرهنگی تپه پیوندهای فرهنگی گردآشوان را با مناطق قفقاز، آناتولی و بین‌‌النهرین نشان داد؛ چراکه گونه سفال کاهرو دارای پراکنش وسیعی در نقاط مختلف است. با توجه به گستردگی این گونه‌‌ی سفالین، آگاهی ما از نحوه تولید آن از جمله بافت سفال، عناصر تشکیل‌‌دهنده، منشا ساخت و فرایند تولید آن اهمیت بسیاری در شناخت تولید و فن‌‌آوری سفال‌‌گری دارد؛ لذا مطالعات آزمایشگاهی می‌‌تواند راه‌گشای تبیین فرایند تولید سفال محسوب گردد. در این پژوهش تلاش شد تا با آنالیز سفال، شناخت دقیق‌‌تری از تولید آنها داشته باشیم. در این راستا با هدف شناخت دقیق‌‌تر از فن‌‌آوری به‌‌کار گرفته شده در سفال‌‌های گردآشوان و شناسایی ترکیبات سفال عصر مس و سنگ، از آزمایش xrf (طیف-سنجی تابش مجهول فلورسانس)، آزمایش xrd (طیف‌‌سنجی پراش پرتوایکس) و پتروگرافی استفاده گردید. تعداد 12 قطعه سفال جهت آزمایش xrf/xrd و تعداد 22 قطعه جهت مطالعه پتروگرافی انتخاب گردیدند. نتایج حاصله نشان ‌‌داد که فاز اصلی تشکیل-دهنده سفال بر اساس آزمایش xrd به ترتیب کوارتز quartz، سیلیس sio2، کلسیت calcite و کربنات کلسیم  caco3است. بر اساس نتایج xrf نیز عناصر سیلیس، اکسید آلومینیوم و کلسیم از عناصر تشکیل‌‌دهنده سفال است. همچنین نتایج آنالیز پتروگرافی هم نشانگر عناصر کوارتز و کلسیت بود که نشانگر هم‌‌پوشانی با آنالیز xrf/xrd است.

pottery making technology from late chalcolithic period in girdi ashoan tepe,(north west iran),based on xrd,xrf and petrography techniques

excavations at gird-i ashoan, an archaeological mound in piranshahr county in the lower zab basin, have provided remarkable insights into the cultural traditions of the region during the late chalcolithic. at gird-i ashoan, the surface layers represented ephemeral iron ii-iii occupations, the mannaean period (sharifi 2021c), totally lacking in architecture. directly below these later contexts emerged the cultural material characteristic of the late chalcolithic, thus marking the presence of a protracted hiatus of several millennia. with its thick deposit of 8.65 m, gird-i ashoan in the zab basin represents a key point in northwestern iran. excavations of gird-i ashoan revealed a late chalcolithic-period deposit, which extended from a depth of 1.00 m down to –9.65 m. results from the excavations of the site are indicative of the interactions and cultural similitudes of the occupants of gird-i ashoan with northwest iran, north mesopotamia, anatolia and the caucasus.the material culture from the site exhibits close relationships with the coetaneous centers of the lake urmia region, on the one hand, and anatolia, the caucasus and mesopotamia, on the other. building on the finds from gird-i ashoan, the present paper addresses the reasons for the chaff-faced pottery’s extension over a wide geographic area from the caucasus to mesopotamia, northern syria and northwestern iran. excavations at the site brought to light a late chalcolithic settlement of an unprecedentedly substantial range, consisting of about 8 m of continuous deposits. the pottery assemblages from the site include chaff-faced ware and painted pisdeli ware, suggesting that the site’s strongest interactions were with the caucasus, anatolia, and mesopotamia. the late chalcolithic is represented by a thick deposit comprised of 24 layers and 4 architectural phases. a contemporary deposit of such depth, 8 meters, is as yet unreported from northwestern iran.the presence of the cfw across vast regions was initially linked to the migrations of mesopotamian groups to transcaucasia (marro 2010: 52). yet, thorough comparison of cfw assemblages excavated from the caucasus down to the fertile crescent, it is now argued that this widespread occurrence does not result, contrary to a frequent opinion, from the migrations of mesopotamian groups into transcaucasia; rather, it developed from a local evolution dating back at least to 4500 bce. the territory spanned by cfw thus constitutes some kind of oikoumene, whose center of gravity is probably located in the highlands, between the euphrates and the kura basins but not in the fertile crescent (marro 2010). the bearers of the cfw culture appear to have lived side by side with the bearers of the kura-araxes culture for a certain while, before the latter supplanted the cfw culture. test results of petrography techniques shows the inclusions identified in the sample under study are: phenocryst and polycrystalline forms, plagioclase, feldspar, pyroxene, iron oxide, silt particles, clay, calcite, and sedimentary. based on the regional geology, these components all point to the local provenance of the raw materials. quartz occurs as fine-grained, mono-crystalline, and semi-rounded inclusion. another inclusion typical to the whole sample , calcite is particularly significant for pottery studies as its serves as a built-in thermometer. it is lost to heat as temperature reaches 800 °c. thus, its presence in any specimen will mean the original piece was fired at a lower temperature.in light of petrography, the ceramics fall into three fabric groups. the first group has porous texture. a lot of empty space can be seen in the paste of this group of samples.group 1 is marked by a silty fabric, having quartz and grog as the dominant component. contrariwise, group 2:the second group is clays with silty texture (fine-grained) and heterogeneous silty. in this group, various minerals such as quartz and calcite are observed in the form of coarse to fine pieces in the clay paste. in general, it can be concluded that quartz is present in most samples. compounds like quartz are present in all soils and it is one of the main components of the soil used in the production of pottery. the presence of calcite is due to lime deposits.