نوع مقاله : مقاله پژوهشی

نویسندگان

1 ژئومورفولوژی، دانشکده جغرافیا، دانشگاه تهران

2 جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران

3 باستان شناسی، دانشگاه آزاد ورامین، پیشوا

چکیده

هدف از این پژوهش، بررسی نقش عوامل محیطی در مکان‌گزینی و نحوه زندگی ساکنان باستانی محوطه پیش از تاریخ چالتاسیان، با استفاده از مطالعات زمین‌باستان‌شناسی و تکنیک میکرومورفولوژی است. محوطه باستانی چالتاسیان، در دشت ورامین و در قسمت‌های میانی مخروط‌افکنه جاجرود قرار گرفته است. پس از بررسی‌های کتابخانه‌ای و میدانی و حفر ترانشه روی تپه شرقی محوطه باستانی، برداشت نمونه رسوب و مکعب در جهت آزمایش‌های غربالگری الکترونیکی، کلسیمتری و میکرومورفولوژی صورت گرفت. با مطالعه مقاطع نازک، عناصر موجود در رسوبات شناسایی و بررسی شد. نتایج نشان داد که بیشترین میزان زغال، گیاه، پرشدگی‌ها و کربنات کلسیم در مکعب رسوبی شماره 9 وجود دارد. از آنجا که وجود این عوامل، رابطه مستقیمی با میزان فعالیت‌های بشری در لایه‌های باستانی دارد، می‌توان نتیجه گرفت که بیشترین میزان دخالت و فعالیت‌های ساکنان باستانی محوطه چالتاسیان در این لایه اتفاق افتاده است. همچنین، پس از آزمایش غربالگری الکترونیکی مشخص شد که تمامی نمونه‌های رسوب، ریزدانه و از نوع ماسه سیلتی و سیلت ماسه‌ای است. این امر با فراهم کردن خاک مناسب کشاورزی و سفال‌سازی، تأثیر بسیار زیادی در مکان‌گزینی محوطه باستانی چالتاسیان داشته است. 

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Geoarchaeological survey of the Chaltasian prehistoric enclosure in Jajrour Fan, using micromorphological techniques

نویسندگان [English]

  • Mehran Maghsoudi 1
  • Seyed Mohammad Zaman Zadeh 2
  • Afsaneh Ehdaei 1
  • Rooho allah Yusefi Zeshk 3
  • Mojtaba Yamani 1
  • Hojjato allah Ahmad pour 3

1 Geomorphology, Faculty of Geography, University of Tehran

2 Natural Geography, Faculty of Geography, University of Tehran

3 Archaeology, Varamin Azad University, Peshwa

چکیده [English]

Characteristics of the natural environment is the most important factor for the formation of human settlements, especially in the ancient eras. Geoarchaeological surveys are the efficient way to discover the environmental features of ancient settlements at the time of their establishment. Geoarchaeology is the application of geological and geomorphological techniques to archaeology and the study of the interactions of hominines with the natural environment at a variety of temporal and spatial scales (Brown, 2008: 278). Micromorphology is one of the appropriate techniques used in this field. Chaltasian ancient enclosure is a prehistoric settlement located on the central parts of Jajrour fan and the aim of this study is the geoarchaeological survey of the Chaltasian prehistoric enclosure in Varamin Plain, using micromorphological techniques.
Materials and Methods
Varamin Plain is situated in the south sastern corner of Tehran on the alluvial sediments of Jajroud River. Chaltasian ancient enclosure is a prehistoric settlement located on the central parts of Jajrour fan. Information needed for this research obtained through a library studies (text and image resources) and field (field visit, trenching and sediment and cube sampling). One trench on the ancient mound was excavated and 22 samples from it were determined. Then, laboratory methods, including Mansel color recognition method, electronic screening, calcimetry and micromorphology were performed in order to analysis the sediments. Also, nine thin sections were prepared for micromorphology testing.
Results and Discussion
The sediment and cube sampling from the trenches on the eastern mound was performed (a total of 22 sediment samples and nine cubes from ancient mound). Most of the sediment samples are very pale and pale brown but colors of some samples are darker or lighter. Being darker is due to the presence of organic materials, particularly coal in ancient layers. Layers closer to pink are more weathered and have nodules more often than the layers with typical brown color. Also, large amount of carbonates gives white or gray color to the soil. For example, the sample 424 on the ancient mound, with white color, has the highest rates of calcium carbonate among the other sediments. After testing and analysis the grain size, it was found that the most of the tested sediments from the ancient mound are sandy silt and silty sand. Fine-grained soil is one of the most important factors influences the site selecting of the ancient settlements thus the economy and livelihood of the ancients, especially in pottery making, dependent on the soil type and existence of the majority of ancient settlements including Chaltasian ancient enclosure in the central part of Jajroud fan has proved it. In this study, man-made elements, filling, the frequency of nodules, the microscopic structure and the relative distribution are the factors studied using micromorphological techniques. The microscopic structure of all thin sections examined was complex and the relative distribution of them was open porphyric. Existence of coal in ancient layers is caused by human intervention and the increase of the amount of coal reflects an increase in the involvement and impact of human activities on sediment layers. Section number 9 has the highest amount of coal that would be caused by the use of the ancient inhabitants of this region as a place for accumulation of household waste, food waste and ash of baking pottery kilns. The amount of clay and pottery at all sections is almost the same. All nodules in thin sections studied, are typical ferruginous nodules and the maximum value was 10% at section number 8. Probably, sections number8 have been exposed longer than the other sections. The type of filling in all sections is dense incomplete and sections number 9 and 10 with 5% has the highest rate of filing. Since this type of filling has a direct relationship with the amount of calcium carbonate, therefore, these two sections have the highest amount of calcium carbonate.
Conclusion
The results showed that the maximum amount of coal, plants, filling and calcium carbonate in the section number 9 have been detected. Since existing these factors have a direct relationship with the amount of human activity in ancient layers, it can be concluded that the highest level of intervention and activities of the ancient inhabitants of the Chaltasyan ancient enclosures have been occurred at this layer. Also, granulometry tests indicated that all sediment samples are silty sand and sandy silt and it provided suitable soil for agriculture and pottery making which had significant influence on aite selecting of Chaltasian ancient enclosures.

کلیدواژه‌ها [English]

  • Sedimentology
  • geoarchaeology
  • Chaltasian prehistoric site
  • micromorphology