فهرست مطالب

نشریه کواترنری ایران
پیاپی 23 (پاییز 1399)

  • تاریخ انتشار: 1400/09/10
  • تعداد عناوین: 7
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  • سید میلاد هاشمی سروندی*، حامد وحدتی نسب، ژیل بریون صفحات 344-367

    امروزه بررسی آماری ریخت ‏شناسانه دست‏ساخته‏ های سنگی و تغییرات و گوناگونی‏های شکل آن‏ها در زمان و مکان اهمیت زیادی در باستان‏شناسی پارینه‏ سنگی یافته است. از دلایل این توجه روزافزون، رواج بهره‏ گیری از روش‏های آماری چندمتغیره در باستان‏ شناسی، ایجاد ارتباط روزافزون میان باستان‏ شناسان و متخصصان برنامه ‏نویسی و علوم زیستی (چون بیوسیستماتیک جانوری)، پیشرفت‏ در فناوری مدرن و روش‏های دریافت اطلاعات، و نیز توانایی روش‏های تحلیل ریخت‏شناسی در پاسخ به برخی پرسش‏هاست که تاکنون پاسخ دادن بدان‏ها یا امکان نداشته یا از عینیت چندانی برخوردار نبوده است. به دلیل همین نیاز به عینیت، استفاده از چنین روشی در باستان‏ شناسی پارینه‏ سنگی ایران ضرورت دارد. امروزه به کمک بررسی ریخت‏ شناسی دست‏ ساخته های سنگی امکان پاسخ دادن به پرسش‏هایی در زمینه های گوناگون چون مباحث ادراکی، سازمان فناوری، بوم ‏شناسی رفتاری انسان، تاریخ فرهنگ، سازوکارهای شارش اطلاعات، و تطور فیلوژنتیکی بیش از پیش مهیا شده است. در این پژوهش یکی از روش‏های بررسی شکلی، به نام «ریخت‏ سنجی هندسی به صورت سه‏ بعدی»، به منظور بررسی تغییرات درزمانی در شکل دست ‏افزارهای سنگی یافت شده از دو لایه باستان‏ شناسی محوطه پارینه ‏سنگی میرک، در جنوب سمنان، استفاده شده است. روش پژوهش هم آزمایشگاهی هم کتابخانه ‏ای است. پرسش اصلی پژوهشی این بود که آیا میان شکل کلی این دست‏ افزارها، که تراشه ‏محور هستند، تفاوتی وجود دارد یا خیر؟ دیگر آنکه در صورت وجود یا فقدان تفاوت، یافته ها چگونه تحلیل می‏شوند؟ نتایج بررسی‏های ریخت‏ سنجی به کمک روش‏های آماری کاهش ابعاد و چندمتغیره نشان داد میان شکل کلی دست ‏افزارهای سنگی نهشته های دوم و سوم میرک تفاوت معناداری از نظر آماری وجود ندارد؛ به عبارت دیگر، ریخت‏ شناسی کلی این دست ‏افزارها دچار تغییری در طول زمان نشده است. به نظر می‏رسد از جمله دلایل این عدم تغییر وجود بزرگ‏ جمعیت‏ها و انتشار اطلاعات فناورانه در پهنه شمال دشت کویر مرکزی، ثبات روش‏های کاهش سنگ مادرهای تراشه، و شکل اولیه مواد خام سنگی با درجات اثر گوناگون باشد.
     

    کلیدواژگان: بزرگ جمعیت ها، دست افزارهای سنگی، ریخت سنجی هندسی سه بعدی، محوطه پارینه سنگی میرک، مرحله سوم ایزوتوپ دریایی
  • ونوس تاثیری، محسن پورکرمانی*، علی سربی، محمود الماسیان، مهران آرین صفحات 369-382

    تحلیل فرکتالی زمین لرزه ها و خط و اره ها و آبراهه ها ابزاری کاربردی جهت ارزیابی فعالیت زمین ساختی هستند. به کمک تحلیل فرکتالی می توان بلوغ ساختاری و پویایی زمین ساختی را ارزیابی کرد. در این پژوهش، با استفاده از تحلیل فرکتالی و بهره گیری از روش جعبه شمارو مطالعات صحرایی به بررسی و مقایسه ابعاد فرکتالی اندازه گیری شده برای شبکه طراحی شده استان البرز پرداخته شد. این شبکه بندی شامل 65 مربع با طول ضلع 5/12 کیلومتر است که ابعاد فرکتالی زمین لرزه ها و خط واره ها و آبراهه های همه آن ها، جداگانه، محاسبه شد. نتایج تحلیل فرکتالی خط واره ها و شبکه آبراهه ها بیانگر فعالیت ساختاری بالا پیرامون گسل های الموت، مشا، شمال تهران، و طالقان در بخش شمالی و گسل های ایپک و اشتهارد در بخش جنوبی منطقه مورد مطالعه بود. علاوه بر آن، با توجه به گوناگونی سنگ شناسی در گستره مورد مطالعه، تحلیل فرکتالی زمین لرزه ها نیز انجام گرفت. پهنه های 54، 55، 45، 46 از فعالیت زمین ساختی بالایی برخوردارند که این نتایج تنها در تحلیل فرکتالی زمین لرزه ها خود را نمایان ساخت. به طور کلی به نظر می رسد فعالیت زمین ساختی در استان البرز به شدت متاثر از فعالیت های گسل های اصلی و البته حضور گسل های فرعی و پنهان (جنوب استان البرز) در منطقه است که در آنالیز ابعاد فرکتالی زمین لرزه ها محرز شد.

    کلیدواژگان: تحلیل فرکتالی، جعبه شمار، زمین لرزه، بلوغ ساختاری، استان البرز
  • علیرضا صالحی پور میلانی*، راضیه مزروعی سبدانی صفحات 383-405

    پادگانه های دریایی مجموعه ای از عوارض تکتونیکی در ایران هستند و در طول سواحل دریای عمان از جاسک تا گواتر امتداد دارند. این پادگانه ها پیوسته در حال بالا آمدن اند و این امر بر مورفولوژی آن ها تاثیر زیادی گذاشته است و نمود بارز آن را می توان شکل گیری پرتگاه های مارنی ماسه سنگی در این مناطق دانست. اما یکی از سوالات مهم در بررسی این پادگانه ها، برآورد میزان برخاستگی این پادگانه ها در بخش های مختلف آن است. هدف از این تحقیق بررسی و برآورد تغییرات ارتفاعی پادگانه های دریایی منطقه کنارک تا کلات با استفاده از تصاویر ماهواره ای، تکنیک تداخل سنجی راداری و همچنین بررسی تاثیر آن بر مورفولوژی این پادگانه ها بود. در این تحقیق از تصاویر ماهواره ای رادار ENVISAT در بازه زمانی 2003 تا 2010 و از آنالیز سری زمانی SBAS برای تحلیل میزان جابه جایی و تغییرات ارتفاع پادگانه های دریایی کنارک، گوردیم، تنگ و کلات استفاده شد. نتایج حاصل از این تحقیق بیانگر آن است که میزان برخاستگی سواحل در پادگانه های منطقه مورد مطالعه یکسان نیست و میانگین میزان برخاستگی از 25/0 میلی متر در سال در پادگانه کنارک در شرق منطقه مورد مطالعه به سمت غرب تا 7/0 میلی متر در سال در پادگانه کلات افزایش می یابد. در بخش هایی از پادگانه های دریایی، هم زمان با برخاستگی، فرونشست هایی مشاهده می شود که دلیل آن را می توان شکل گیری گسلش های نرمال در این منطقه و فرونشینی سطح پادگانه ها دانست. این برخاستگی ها و فرونشست ها بر مورفولوژی پادگانه های دریایی تاثیر گذاشته و اشکال ژیومورفولوژی همانند پرتگاه های مارنی ماسه سنگی متعدد را در این منطقه به وجود آورده است. علاوه بر آن بررسی ها نشان می دهد بالاترین سطوح ارتفاعی در پادگانه های دریایی منطبق بر مناطقی است که میزان برخاستگی آن ها بیشتر از سایر نقاط است.

    کلیدواژگان: برخاستگی و فرونشینی، پادگانه های دریایی، تداخل سنجی راداری، کلات، کنارک
  • طاهره جلیلیان، علیرضا تقیان *، راضیه لک، جواد درویشی خاتونی صفحات 407-432

    در این پژوهش، ضمن جمع آوری اطلاعات قبلی در ارتباط با مطالعات اقلیم دیرینه و رسوب شناسی، اقدام به برداشت 16 مغزه رسوبی با بیشینه ژرفای 5/11 متر به صورت دست نخورده از رسوبات بستر پلایای گاوخونی توسط مغزه گیر اوگر شد. رخساره های رسوبی بر اساس رنگ، اندازه دانه، ساخت رسوبی، شکل دانه، و نوع کانی های تبخیری تفکیک شدند. نمونه برداری بر اساس تغییر در نوع رسوبات و رخساره های رسوبی انجام گرفت. تعداد 80 عدد نمونه رسوبی جهت آنالیز دانه بندی تفکیک شد. دانه بندی نمونه ها به دو روش الک مرطوب و ذرات ریزتر از ماسه (سیلت و رس) توسط دستگاه لیزر انجام گرفت و با استفاده از نرم افزار سدی لایزر پارامترهای آماری رسوب‏شناسی محاسبه شد و در نرم افزار SPSS مورد تحلیل قرار گرفت. تیپ غالب رسوبات بستر پلایا گل و محیط های رسوبی بادی، رودخانه، دلتا، دریاچه، و پلایا است. با توجه به آنالیز سن سنجی به روش ایزوتوپی C14-AMS، میزان رسوب گذاری در بخش‏های غربی حدود 4/0 میلی متر و بخش‏های شرقی 25/0 میلی‏متر در سال بوده است. در این مطالعه دو دوره مهم خشک (8200 و 4500 سال پیش) در رسوبات هولوسن بستر پلایای گاوخونی شناسایی شد که حاکی از خشک شدن و گسترش رسوبات بادی در بستر پلایاست.

    کلیدواژگان: پلایای گاوخونی، رسوب شناسی، مغزه رسوبی، نهشته های بادی، هولوسن
  • حسین باقری، آرش امینی* صفحات 433-448

    در این مطالعه جهت بازسازی تغییرات عمده اقلیمی در بخش جنوب شرقی دریای خزر یک مغزه رسوبی (N1) به طول 712 سانتی‌متر توسط مغزه‌گیر لرزه‌ای از بخش جنوبی خلیج گرگان و ساحل نوکنده برداشت شد. در آزمایشگاه، جهت بررسی نوع رسوبات، 89 نمونه در طول مغزه برداشت شد و آنالیز لیزری ‌دانه‌بندی روی آن‌ها انجام گرفت. همچنین، جهت بررسی دمای دیرینه آنالیز ایزوتوپ‌های پایدار کربن و اکسیژن در 20 نمونه فرامینیفر و جهت سن‌سنجی نمونه‌ها آنالیز کربن 14 در 3 نمونه حاوی ماده آلی صورت پذیرفت. نتایج ‌دانه‌بندی نشان داد این مغزه از 6 رخساره اصلی تشکیل شده؛ شامل 39 رخساره سیلت ماسه‌ای (sZ)، 28 رخساره سیلتی (Z)، 9 رخساره ماسه سیلتی، 9 رخساره گل ماسه‌ای گراول‌دار، 3 رخساره ماسه گلی گراولی، 1 رخساره ماسه گراولی. محدوده سنی آن نیز از حدود 22000 در قدیمی‌ترین واحدها تا عهد حاضر است. در جمع‌‌بندی نهایی مشخص شد بیشترین دما 4/27 درجه سانتی‌گراد مربوط به دوره قبل از یخبندان بزرگ و کمترین دما 9/13 درجه سانتی‌گراد مربوط به آخرین اوج یخبندان (Wurm) بوده است. در نهایت، با انطباق داده‌های مختلف، 7 دوره تغییرات عمده اقلیمی سرد و گرم طی 22000 سال در این منطقه مشخص شد.

    کلیدواژگان: تغییرات اقلیمی، جنوب شرقی دریای خزر، رخساره های رسوبی، کواترنری، مغزه های رسوبی
  • محسن جهان بین، سید رضا مهرنیا*، حمیدرضا شیروانی مهدوی، حبیب رحیمی صفحات 449-468

    هدف اصلی این پژوهش شناسایی گسل‏ها در منطقه درکه تهران بود. برای این منظور، پروفیل‏های ژیوالکتریک با آرایه ونر شلومبرژه، رادار نفوذی به زمین (GPR)، و برای سنجش فرکتالی پروفیل ژیوالکتریک از تابع نمایی پراش مسافت استفاده شد. در بازدیدهای میدانی انجام شده شکستگی‏ها و گسل‏ خوردگی‏هایی با امتدادهای مختلف در سطوح وسیعی از سنگ‏های منطقه تشخیص داده شد. گسل شمال تهران مهم‏ترین و تاثیرگذارترین گسل منطقه مورد مطالعه است. از دیگر گسل‏های فرعی منطقه می‏توان به گسل‏های امامزاده داود و دربند و شیرپلا اشاره کرد. نتایج پردازش پروفیل ژیوالکتریک نشان دهنده افت بسیار شدید مقاومت ویژه در فاصله 96 متری پروفیل به علت وجود یک زون گسلی است. کمینه تغییرات مقاومت ویژه الکتریکی تحت روش فرکتالی انجام شده نشان دهنده روند خطی همراه با افت نسبی بعد فرکتال است. در برخی مناطق افزایش نامتعارف بعد فرکتال و ایجاد شرایط آشوبناک بیانگر مناطق گسله و خردشده است. همچنین، تغییرات مرتبط با افت شدید دامنه امواج الکترومغناطیسی در رادارگرام GPR در فواصل 90 تا 100 متری موید وجود حتمی زون گسلی در منطقه مورد مطالعه است.

    کلیدواژگان: آرایه ونر، بعد فرکتال، رادار نفوذی به زمین، شلومبرژه، گسل شمال تهران
  • محمدجواد بهمنی، خلیل رضایی*، عبدالرضا هاشمی صفحات 469-483

    خطوط ساحلی از مناطقی هستند که حساسیت بالایی در برابر فرسایش و رسوب‏گذاری دارند. خطوط ساحلی همواره مورد توجه کاربری ‏های انسانی قرار دارند. ولی با توجه به پتانسیل تغییرپذیری بالایی که دارند در معرض مخاطرات هستند. از مخاطرات رایج مناطق ساحلی پس روی و پیش روی خطوط ساحلی است. با توجه به اهمیت موضوع، در این پژوهش به بررسی تغییرات خطوط ساحلی جنوب استان خوزستان پرداخته شد. در این پژوهش به منظور دستیابی به اهداف مورد نظر از مدل رقومی ارتفاعی 30 متر SRTM، تصاویر ماهواره لندست، نقشه‏ های توپوگرافی 1:50000، و نقشه‏ های زمین‏ شناسی 1:100000 به عنوان داده‏ های تحقیق استفاده شد. ابزار مورد استفاده Arc GIS‏، ENVI، IDRISI بود. روش کار در این تحقیق به این صورت بود که ابتدا تصاویر ماهواره لندست سال‏های 1990، 2000، 2010، 2020 تهیه و پیش‏پردازش‏های لازم بر آن ها انجام گرفت. پس از آن نقشه ‏‏های پوشش زمین طی دوره‏های زمانی مورد مطالعه تهیه شد. سپس با استفاده از مدل LCM روند تغییرات خط ساحلی منطقه ارزیابی شد. بر اساس نتایج حاصله، خط ساحلی جنوب خوزستان با تغییرات زیادی مواجه شده است؛ طوری که طی سال‏های 1990 تا 2020 حدود 707 کیلومتر مربع از خشکی‏های منطقه مورد مطالعه به پهنه آبی تبدیل شده که عمدتا مربوط به فرسایش نوارهای ماسه ‏ای و همچنین پیش‏روی دریا بوده است. همچنین، در این دوره حدود 5/14 کیلومتر مربع از پهنه آبی به خشکی تبدیل شده است.

    کلیدواژگان: تصاویر لندست، تغییرات ساحلی، ساحل خوزستان، مدل LCM
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  • Seyyed Milad Hashemi Sarvandi*, Hamed Vahdati Nasab, Gilles Berillon Pages 344-367

    The study of the morphology of stone artifacts and their spatio-temporal changes in form has gained great importance in Paleolithic archaeology today. This growing attention is due to the prevalent use of advanced multivariate statistical methods in archaeology, the growing connection between archaeologists and the specialists of life sciences (e.g., animal biosystematics) and programming languages, advances in modern technology and data acquisition, as well as the ability of the statistical shape analysis methods to answer some questions that have not been possible to answer or the answers lacked acceptable dose of objectivity. Nowadays, using the help of stone artifacts shape analysis, it is becoming more and more feasible to deal with some hithertho-impossible questions in various domains such as cognitive topics, technological organization, human behavioral ecology, cultures’ history, the mechanisms of cultural transmission, as well as the investigation on phylogenetic evolution of artifacts. Here, a 3-d geometric morphometric approach is used to dealing with the diachronic variabilities of stone tools in shape. The tools are flake-based and are recovered from the two MIS 3 archaeological layers of Mirak, an open-air Paleolithic site near the modern city of Semnan in the northern fringes of Iranian Central Desert. The research is done using both computer-based post-excavation analysis and library research method. The research main question is whether there are morphological differences between the two sets of flake-based lithic tools. The results of the morphometric study using dimensional reduction and multivariate statistical methods indicated that there is no statistically significant difference between the tools of the two layers (deposits) mentioned; put in another way, the morphology of the tools has not changed over time. It seems this is due to the presence of metapopulations and the resultant survival of technological information in the region of study, the stability in flake core reduction methods, and finally, the original morphology of lithic raw material. 

    Introduction

    The study of the morphology of stone artifacts and their spatio-temporal variabilities in form have gained great importance in Paleolithic archaeology today. This growing attention is due to the prevalent use of advanced multivariate statistical methods in archaeology, the growing connection between archaeologists and the specialists of life sciences (such as animal biosystematics) and programming languages, advances in modern technology and data acquisition, as well as the ability of the statistical shape analysis methods to answer the questions more objectivity. Various methods have been developed to study the morphological variability of stone artifacts through space and time; one of them is called geometric morphometrics (GM), meaning the application of the geometrical principles to the statistical study of morphology. In one of the three general modes of GM, called landmark-based GM, the shape of artifacts is examined using comparable landmark and semilandmark points created on the Cartesian coordinate system. Such points, created on a two- or three-dimensional image of stone artifacts could help to grasp the inter- and intra-assemblage shape variabilities via the help of multivariate statistics. As a result, the researcher could be able to address the variables involve in creating various shapes. The ultimate goal of such studies is to inspect the mechanisms and reasons behind in creating such variabilities; among them are stochasticity, the original shape and type of raw material, reduction intensity and technique, function, ecology, cultural traditions and biomechanical and cognitive differences. Here, this method is used to investigate on the shape variabilities of the flake-based stone tools recovered from Mirak Paleolithic site.

    Materials and Methods

    Here, a 3-d GM approach is used to dealing with the diachronic variabilities of stone tools in morphology. The tools are flake-based and are recovered from the two archaeological layers of Mirak, both of Marine Isotope Stage 3. Mirak is an open-air Paleolithic site located near the modern-day city of Semnan, Iran, at the northern edges of Iranian Central Desert. The statistical population is comprising of 76 tools, 31 of which from the younger layer (layer 2), and the remainder (45 specimens) of layer 3 (late Middle Paleolithic Period). Thus, here we are dealing with two groups of comparable materials from one Paleolithic landscape to investigate their similarities and differences through time (diachronic approach). After the preparation of the 3-d models of the lithic tools via light scanning (desktop Shining 3D scanner), the cloud points were analyzed using a shape analysis software called AGMT-3d and the help of some dimensionality reduction techniques such as principal component analysis. Finally, the data were assessed using some formal significance tests.

    Results and Discussion

    The results of the landmark-based GM study using dimensional reduction and multivariate statistical methods indicated that there are no statistically significant differences between the lithic tools of the two layers mentioned; put in another way, the morphology of the tools has not changed drastically over time. This may bear some implications for raw material original shape, the reduction techniques, population dynamics, and their adaptive strategies. As far as the general morphology has remained unchanged, this may imply the impact of the original lithic raw material shape, the presence of metapopulations in the landscape throughout MIS 3, and the flow of information regarding core reduction techniques. Due to the radical size differences between the lithic raw material scatters in the landscape and Mirak flake-based tools, it seems the form of lithic raw materials was not the main factor determining the shape of the tools. Additionally, the absence of flake cores makes the comparison of the shape and dimensions of the candidate raw materials and tools difficult, due to the fact that cores are intermediate forms influenced from the original lithic raw material form and have great impact on the morphology of the detached flake blanks. In addition to what mentioned, based on the fluctuations in climatic-environmental characteristics in the landscape throughout MIS 3, it seems the comparability of the blanks of the flake-based tools is not solely due to similar adaptive strategies in the two different time periods (layers 2 and 3), since the environement was probably different in Mirak landscape with rather unpredictable incidents in the two periods. Therefore, the comparability of the flake blanks in the two discontinuous archaeological sets in Mirak could probably be attributed to the population dynamics and the presence of metapopulations in the landscape which prevented the loss of previous information and techniques.     

    Conclusion

    Based on what mentioned, it seems at least part of the comparability of the flake debitages is due to the presence of metapopulations in the landscape and this fact that the populations did not abandon the region completely during the periods with unfavorable environmental characteristics. The reasons behind the sticking with the region was probably due to the existence of some small refugia, the candidates of which are the western part of the Iranian Central Plateau or the more northern landscapes than Mirak near the locations of the modern population centers in the region today. Therefore, despite the time gap between the two archaeological sets, part of the comparability of flake blanks shape in Mirak is due to the survival of information regarding the reduction techniques with the help of the interrelated populations in the region.

    Keywords: Mirak Paleolithic site, lithic tools, 3-d geometric morphometrics, MIS 3, Metapopulation
  • Venus Tasiri, Mohsen Pourkermani*, Ali Sorbi, Mahmoud Almasian, Mehran Arian Pages 369-382

    Fractal analysis of earthquakes, lineages and waterways are considered as one of the practical tools to evaluate tectonic activity. With the help of fractal analysis, structural maturity and tectonic dynamics can be evaluated. In this research, using fractal analysis and box counting method and fild studies, the measured fractal dimensions for the designed network of Alborz province were studied and compared. This network consists of 65 square meters with a side length of 12.5 km, for which the fractal dimensions of earthquakes, lines and waterways were calculated separately for all of them. The results of fractal analysis of lineages and network of waterways show high structural activity around Alamut, Mosha, north of Tehran and Taleghan faults located in the northern part and Ipak and Eshtehard faults in the southern part of the study area. In addition, due to the diversity of lithology in the study area, fractal analysis of earthquakes was performed and areas 54, 55, 45 and 46 have high tectonic activity, which these results only in the fractal analysis of earthquakes. Showed. In general, it seems that tectonic activity in Alborz province is strongly affected by the activities of major faults and, of course, the presence of sub-hidden faults (south of Alborz province) in the region, which was found in the analysis of fractal dimensions of earthquakes.

    Keywords: Fractal analysis, box counting, earthquake, structural maturity, Alborz province
  • Alireza Salehipour Milani*, Razyeh Mazruie Sabadani Pages 383-405
    Introduction 

    The Coastal terrace is a unique tectonic complication in Iran and covers more than half of the Oman Sea coast from Jask to Quatre. These beaches are constantly rising and this has greatly influenced the morphology of the formation and deformation of Makran coasts marine terrace, which can be seen in the formation of coastal cliffs in these areas. But one of the important questions in the study of these terraces is to estimate the rate of rise of these coasts in its different parts and its impact on the formation of coastlines in these areas. The aim of this study is to investigate the altitude changes of marine terraces in the area from Konarak to Kalat using satellite images and Radar interferometry technique and its effect on the morphology of them.   Study area the study area is located on the coast of Makran and between Konarak in the east to Kalat in the west. These terraces are separated by the Gulf of Pozm and Gordim. This coastal area is affected by the Makran subduction zone. Lithologically, the bedrock of Makran coast in eastern Iran includes Upper Miocene to Pliocene sandstones. Fluctuations in the water level and tectonic changes and equilibrium movements of faults in this region have made the tectonic history of this region very complex, especially on the shores of the Oman Sea. Which are especially widespread on the beaches of Makran.  

    Material and Methods

    In this study, with the aim of investigating the deformation rate of Oman marine terraces between Konarak port and Kalat port, ASAR radar sensor satellite data of ENVISAT were used. The time series studied in this study is between 2003 and 2010 and the data analysis was performed in Sarscape software in ENVI 5.3 environment.the short baseline algorithm was used in order to analyze the time series and estimate the deformation rate of marine terraces, lineation of marine terrace is determined using Geomatica and Landsat 8Oli satellite data and direction of this lineation cpmputed using Rockwork software.  

    Result and Discussion 

    The rate of change ranged from -3.4 to 2.2 and the average displacement rate was about 0.25 mm per year in Konarak terrace. The simultaneous presence of subsidence and uplift in this terraces indicates the different performance of tectonic processes in this area. This indicates that the uplift in Konarak terrace is about 1.8 mm during the study period of more than seven years (03/05/2003 to 07/08/2010). This rate is about 2.78mm for Gourdim terrace and 5.7mm in Kalat. In Makran Marine Barracks, several normal faults have led to the movement of sediments and terraces. These normal faults are associated with regional subsidence of the coastal plain, although this may be locally formed as a result of differential uplift.In addition, the extension of the main lines in the terraces of the study area is mostly east-west, and this trend is in line with the east-west extension of the Makran subduction zone, indicating that the impact of the collapse of the Saudi plate under the crust Iran has led to the transformation of the coastal region of the Oman Sea.

    Conclusion

    In this study that uses satellite data ENVISAT-ASAR and SBAS model were performed. The uplift and subsidence rate of marine terraces in this part of the Iranian coast was investigated and the results show the appropriate accuracy of this data and model in the study of these geomorphological forms of the coastline. Tectonic activities have different functions in different parts of these areas and this has led to the formation of uplift and subsidence in different parts of these terraces. The height of the uplifted coasts is directly related to their uplift rate and this parameter decreases from the west of the study area (Kalat) to the east. This is inconsistent with previous assumptions about the increase in altitude of marine terraces from west (Jask) to east, and the rate of uplift of terraces could be a function of locally different geological features.but the results show that the average rate of rise of these beaches in the study period is only about 0.45 mm.

  • Tahereh Jalilian*, Alireza Taghian, Raziyeh Lak, Javad Darvishi Khatooni Pages 407-432
    Introduction

    Identification of the climate changes is important for understanding the paleoenvironmental characteristics. Sedimentary evidence of the closed basins can be one of the most important methods for identifying the climatic periods and changes in the sedimentary environments. Gavkhouni Playa, as the lowland of the ZayandehRud River catchment area is located in an inter-mountainous basin in the Central Iran. This area is one of the pits separating the Sanandaj-Sirjan tectonic zone from the Central Iran, located parallel to the Zagros over thrust. A total of 16 sedimentary cores were taken from the inner part of the Gavkhouni Basin, the outer part of the basin, and the surrounding lands in order to investigate the sedimentary environments of the Gavkhouni Playa during the Late Quaternary.

    Methods and Findings

    The steps of this research include book studies, field works, laboratory works, data processing and then interpretation and conclusion. To investigate the paleontological climate and conditions of the sedimentary environment, 16 intact sediment cores with the mean depth of the sedimentary cores was equal to 7 m and its maximum depth was equal to 11.5 m. Sedimentary facies were identified and separated based on the sedimentary texture, type of evaporite minerals, presence of organic materials, color changes, and other microscopic components, and sampling was performed based on the changes in types of sediment and sedimentary facies. A total of 80 sediment samples were selected for granulation analysis by two methods of wet sieving for coarse-grained particles and laser particle Sizer Analysette for particles smaller than sand (Silt and Clay). Sedimentology parameters were calculated by the SediLizer software and the results were analyzed statistically by the SPSS software. Also, 3 sediment samples sent to the Marmara Research Center, Earth and Marine Sciences Research Institute in Turkey to age measurement analyzing by the radiocarbon method of organic matters.

    Results and discussion

    In the studied cores, 8 major sedimentary facies identified. The facies often contains clay, silt, sand, gravel, and interstitial sediments along with vegetation and shell fossils which in most cases frequency and interference in the mentioned sediments are often seen. Changes were in particle size between clay to gravel due to process type changes, environment's energy and river input's amounts and sediment color variations concerning sedimentation conditions, presence of organic matter, pH amount, salinity and temperature variations, and drought occurrence, throughout the cores. The results of the analyses indicated the identification of eight sedimentary facies, five sedimentary environments, and two types of wind and water processes, which are effective on the sedimentation of the Gavkhouni Playa sub-surface. The major types of sediments in the Gavkhouni Playa sub-surface, mud, and sedimentary environments included the aeolian, river, deltaic, lake, and playa environments. According to the C14-AMS isotope dating analysis, sedimentation rate is about 0.4 and 0.25 mm in the western and eastern parts per year, respectively. According to dating analysis, the paleogeography of the Gavkhouni Playa and the extent of its expansion have been reconstructed at least 40,000 BP. According to the studies, about 18-40 ka BP, the Gavkhouni area has been influenced by the heavy precipitation so that, the amount of sediment load imported from the west (ZayandehRud River) has been high. The great Delta of ZayandehRud has been formed and the coarse-grained particles have been deposited in the gravel and sand sizes. Since, 11.6 -18 ka BP, along with the coastline regress, the great Delta of ZayandehRud has flowed into north of the basin. The end of Delta stretches until the center of the Playa, and sand dunes have been formed to the west of the basin. With the onset of Holocene and the increase in the temperature, it has led to an increase in the size of the aeolian sand deposits and the expansion of the playa environment until about 8.2 ka BP on the margin of the lake. Since, 4.2-8.2 ka BP, it has been accompanied by a temporary progress of the Gavkhouni Lake, and 4.2 ka BP, it has regressed again with a drought occurred about 200 years ago. The progress of the lake facies has taken place about 3.5 ka BP, after which regression has occurred and playa and aeolian facies have replaced with the lake facies. According to the type of the sediments in the Gavkhouni sub-surface, it can be said that, the conditions of the northern and eastern parts of the Gavkhouni Playa have been similar to the current conditions for at least the last 3000 years and also the conditions of the western part for at least the last thousand years. The increase in the thickness of the layers of evaporite sediments, which are mainly salt, in the upper layers of the playa indicated that the Gavkhouni Playa has become drier than before in the recent centuries.

    Conclusion

    According to the results the Gavkhouni Basin has extended to the western part of the sand dunes during the Late Pleistocene. During the Early-Middle Holocene, coastline regress and the ZayandehRud Delta progress toward the Playa have occurred in the northern part of the area. During this time, aeolian sands have spread to the Gavkhouni Playa. In the Late Holocene, semi-arid conditions have reduced the water levels, coastline regress has occurred, and playa environment has been dominated in the Gavkhouni margin. But, there were still lake conditions in the center of the Playa. Gavkhouni Playa has experienced an increase in the level and progress of the coast towards the land about 3 ka BP. The creation of arid conditions about 1000 cal BP has turned the entire Gavkhouni zone into a playa environment, and this situation has been dominated the area almost to this day.

    Keywords: Gavkhouni playa, Paleoclimatology, Paleogeography, Sedimentary core, Holocene
  • Hossein Bagheri, Arash Amini* Pages 433-448
    Introduction 

    Reconstruction of past climate change can provide us valuable information about the time, scale, and details of climate changes. For reconstruction of late quaternary climatic conditions, various methods are used, as well as the use of losses, paleomagnetism, paleontology, etc.One of these methods is to use stable isotopes of carbon and oxygen, which is particularly valuable information on the temperature of the depositional environment, digenesis temperature, the temperature changes in different digenesis environments, separating different areas carbonates offers Considering the importance of Gorgan Bay from different aspects and the fact that not many studies have been done in this region regarding long-term climate change, in this research we have tried to use different data obtained from sedimentary cores harvested from the southeastern part. Caspian Sea (Gorgan Bay) Temperature changes and environmental conditions of the region in the late Quaternary to be studied and reconstructed. Gorgan Bay with an area of more than 400 km is located in the southeastern part of the Caspian Sea (36°48’N, 53°35’E and 36°55’N, 54°03’E, 60 km ×12 km, maximum depth of 4 m ). Gorgan Bay formed during the Holocene period by a sandy spit which is named Miankaleh coastal barrier system. It is connected to the Caspian Sea through the inlet of Ashoradeh-Bandar Torkaman (Chapaghli) which is located in the northeastern part of the Bay This bay is mainly influenced by processes that are operating within the basin. Water balance in the Gorgan Bay is influenced by freshwater inflow from a number of small rivers and streams, including Gorgan-roud from the north and QarehSu from the east. These two rivers drain runoffs from residential and agricultural areas into the bay.

    Materials and methods

    In this for reconstruction of late Quaternary climatic conditions a sedimentary core (N1) were collected from Gorgan Bay using a gravity corer. The core was first examined for magnetic susceptibility (MS). After slicing the core and subsampling with certain distances, Laser particle size analyzer used (Horbia LA-950) for grain size analysis. Also to specify total organic matter content (TOM), loss of ignition method (L.O.I) was used. For this purposes, a portion of each sample (about 3 gr) was placed inside a crucible and heated at 550 ° C for 5 hours and after that the weighing percentage of the organic material was reported. For measurement of carbonate content (CaCO3%), coarser grain particles were manually removed and remaining sediments were placed in a muffle furnace (Excitation, EX.1200-12L) for 1 hour at 950 °C . For 14C dating, totally 3 organic matter samples were sent to the Poznan Laboratory, Poland, The oxygen and carbon stable isotope analysis was carried out on the non-digenetic and negligible digenetic benthic foraminifera (Ammonia Beccari) by mass spectrometer in the Winsor Laboratory, Canada. Paleotempreture of the seawater estimated based on δ18O values for seawater and its counterpart in aragonite.

    Results and discussion

    Grain size, was very variable from sand to clay. N1 core consists of 39 sandy silt facies, 28 silty facies, 9 silty sand facies, 9 facies of gravelly sandy mud , 3 facies gravelly muddy sand and 1 facies gravelly sand. The maximum and minimum ​​of sand were abstained at 617 and 690 cm (80.27% and 0%), respectively, while the highest content of silt and clay were at depth 138 and 416 cm (99.45% and 8.95%), respectively. The lowest amount of silt content was observed at 626 cm (7.23%). The average of sand, silt and clay in this core was 25.13%, 72.52% and 1.56%, respectively. Result of magnetic susceptibility showed a close relationship between particle size distribution and MS magnitude due to variation in terrestrial influx, which is caused by sea-level fluctuations in different times. This process increases with particle size and ranges of MS simultaneously with sea level fall and decreases during sea-level rise. The range of oxygen (δ18O) and carbon isotope (δ13C) was between -4.22 to -1.17‰ and 2.66 to‏ -0.94‰ with a mean of 3.34 and -2.11 ‰ correspondingly. According to the results of carbon dating (14C Dating), age of sediment in the N1 achieved 22070 cal. The rate of sedimentation in the cores varied from 0.57 to 3 mm. Reconstruction of paleotemperature with stable isotopes showed that the maximum temperature recorded in the core was acquired at 144 and 686 cm (27.4 and 27.1°C) and the minimum temperature was 450 cm (13.7°C). The mean temperature in this core was 22.2°C.

    Conclusion

    1-Caspian sea sediments as one of the best region in the world ,record Quaternary climate change in northern IRAN. 2- Accordingly, seven warm and cold periods were identified, which the coldest period being the last glacial maximum (Wurm) with a temperature of 13.7 °C. Furthermore, the highest temperatures related to the pre-glacial and the present periods (about 27°C). Moreover the sedimentology and magnetic susceptibility data confirmed the above results. 3-The degree of magnetic susceptibility in different core subsamples indicates environment conditions and low sediment rate. 4 - The rate of sedimentation in the cores varied from 0.57 to 3 mm. 5 - Reconstruction of paleotemperature with stable isotopes showed that the maximum temperature recorded in the core was acquired at 144 and 686 cm (27.4 and 27.1°C) and the minimum temperature was 450 cm (13.7°C). The mean temperature in this core was 22.2°C. 6 - Based on the results of 14C age and stable isotopes 15 centigrade changes in temperature have occurred during about 22,000 years.

    Keywords: Climate changes, Sedimentary Cores, Sedimentary Facies, South east of Caspian Sea
  • Mohammad Javad Bahmani, Khalil Rezaie*, Abdolreza Hashemi Pages 469-483
    Introduction

    The location of shorelines and the state of their changes in the past, present and over time are important for scientists, engineers and managers. For example, analyzing shoreline information for coastal protection design, policy development, updating and reviewing numerical models, assessing sea level rise, developing risk areas for coastal development, achieving the definition of legal property boundary, research and Coastal monitoring is essential. In this article, first the rate of progress and regression of the coastline of southern Khuzestan during the years 1990 to 2020 is examined and then the issue of which part of the coastline of Khuzestan has the most variability is discussed. In this regard, the research hypotheses of variability above the coastline of southern Khuzestan due to the presence of sand masses and most variability of the western parts of the coast of Khuzestan due to the composition of sand masses is the management of coastal areas and implementation Engineering projects in these areas require information such as the current location of the shoreline, its location in the past, and forecasting its location in the future.

    Materials and methods

     Khuzestan province, with 927 km of land border and 975 km of water border, has 136 and 632% of the total land and water borders of the country, respectively (Report of the Geological Survey of Iran, 2016). These figures are equivalent to 635% of the total land and water borders of the country and Khuzestan province is in the sixth place among the border provinces of the country in this regard. The tools used in this study include 1: 50,000 topographic maps, 1: 100,000 geological maps to study the topographic and geological status of the area, the most important of which are Arc GIS, ENVI, IDRISI, SPSS. In this research, achieving the intended goals has been done in several stages, which are described in the following steps. The first stage includes gathering the desired information about the region as well as theoretical foundations on the subject under study. The second stage includes collecting information and layers needed to study the natural state of Khuzestan province. In the third stage, in order to prepare land use maps, Landsat satellite images have been downloaded from the relevant site. After preparing the images, the necessary pre-processing has been done on the images, and finally the land use maps of the area related to the years 1990, 2000, 2010 and 2020 have been prepared. Finally, after preparing land use maps, using the LCM model, the changes made have been studied and analyzed, and using it, the trend of shoreline changes during the study periods has been evaluated.

    Results and discussion

    In this study, in order to evaluate the changes in the coastline of the south of Khuzestan province, multi-time satellite images were used. The study of land cover during different periods indicates that the coastlines of Khuzestan province are associated with high variability. In fact, due to the fact that a large part of the coasts of Khuzestan province is covered by low-slope and low-altitude sand strips, these coasts have a high potential for erosion and are affected by the retreat and advance of the sea. The study of the coastline in the study area indicates that the coastline of the south of Khuzestan province is facing a lot of fluctuations and during different periods under the influence of hydro-climatic factors, erosion and sedimentation, has been faced with many changes so that during the year Between 1990 and 2000, much of the coastal sand strip was submerged and actually turned into a blue zone. Most of the changes made during this period were on the southern coast of Bandar emam Khomeini. Between 2000 and 2010, sand strips advanced into the sea and shrinked due to sea retreat and sedimentation. Between 2010 and 2000, it was again faced with the advance of the sea and the increase of the water area, which, like the previous periods, had the most changes in the southern shores of Imam Khomeini port.

    Conclusion

    In this study, according to the objectives, the changes of coastlines in the southern coasts of Khuzestan province have been investigated using Landsat satellite images. In this study, first the land cover map related to the years 1990, 2000, 2010 and 2020 was prepared and then the temporal and spatial analysis of changes was performed and then the trend of changes in the coastlines of the study area was evaluated. The results of the evaluation of shoreline changes during the years 1990 to 2020 also indicate that in this 30-year period, due to the fact that the shorelines of the study area are mainly composed of sand strips, it faces many fluctuations and changes. According to the results, during the years 1990 to 2020, about 707 square kilometers of land in the study area has been converted into a water zone, which is mainly related to the erosion of sand belts as well as the advance of the sea. In addition, during this period, 1.6 square kilometers of vegetation and 1.1 square kilometers of man-made areas have been converted into water. Also, the results of the assessment of land cover changes during the years 1990 to 2020 indicate that during this period, about 14.5 square kilometers of water has been converted to land. According to the results, the amount of about 12.3 square kilometers was related to the conversion of water zone to sand zone, the main reason for which is sedimentation and movement of sand masses towards the iodine water zone.

    Keywords: Coastal changes, LCM model, Landsat images, Khuzestan coast