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کواترنری ایران - پیاپی 3 (پاییز 1394)

نشریه کواترنری ایران
پیاپی 3 (پاییز 1394)

  • 116 صفحه،
  • تاریخ انتشار: 1394/10/28
  • تعداد عناوین: 7
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  • الهام مجتهدین، فاطمه هادوی، اکرم پوراسماعیل صفحه 181
    نانوپلانکتون های آهکی یکی از مهمترین گونه های فیتوپلانکتونی جهت بازسازی محیط های دیرینه می باشند. گونه Braarudosphaera bigelowiiدر مجموعه های ساحلی و آب هایی با میزان شوری پایین و همراه با ورود مواد آواری زندگی می کند. بررسی های انجام گرفته بر روی نمونه های خلیج فارس، شرق تنگه هرمز و دریای عمان (سیریک) بر اساس پراکندگی این گونه، نشان دادند که فراوانی این گونه در مناطق مذکور نسبتا کم بوده وحضور این گونه در بخش غربی خلیج فارس به دلیل ورود مواد آواری و آب های شیرین از رودخانه هایی است که در این بخش به خلیج فارس می ریزند، در قسمت های مرکزی به دلیل شوری و تبخیر بالا فراوانی آن خیلی کم و نزدیک به تنگه هرمز که شوری نسبتا کمتر است دارای فراوانی کم و نهایتا در شرق تنگه هرمز و دریای عمان (سیریک) که میزان شوری بالا می باشد، این گونه حضور ندارد.
    کلیدواژگان: شوری، خلیج فارس، دریای عمان، Braarudosphaera bigelowii
  • فهیمه جاجرمی، حامد وحدتی نسب، محمد قمری فتیده صفحه 191
    انسان مدرن و تمامی فعالیت هایش از ابتدای پیدایش –در حدود 200000 سال پیش-، تا کنون، با اقلیم و محیط پیرامون خود در ارتباط بوده است، از آن تاثیر گرفته و بر آن اثراتی گذارده است. اقلیم کره ی زمین به مانند یک سیستم پویا، از تاریخ ذکر شده تا امروز در حال تغییر و تحول دایمی بوده است. تغییرات اقلیمی، از راه ایجاد تغییرات در مولفه های محیطی و ویژگی های چشم انداز کنام زیستی گروه های انسان مدرن، بارها و بارها دشواری ها، محدودیت ها و چالش هایی بر سر راه این گروه ها قرار داده است. در این برهه های اصطلاحا بدخیم اقلیمی، انسان مدرن گهگاه مجبور می شد از مهارت خود (زیر مجموعه ای از فرهنگ)، هوش در حال تطور و توانایی خروج از چشم اندازهای ناپسند (به اقلیم های مورد پسند) برای حل و یا دست و پنجه نرم کردن با این مشکلات استفاده کنند. همین بر هم کنش با اقلیم و زیست بوم چشم انداز یکی از مهم ترین عواملی بود که به تدریج نیاکان ما را به انسان های مدرن از نظر رفتاری (انسان هوشمند هوشمند) تبدیل کرد. تغییرات اقلیمی علاوه بر ایجاد خطرات بالقوه، از عوامل مهمی بود که موجب برانگیزش انسان مدرن برای افزایش انعطاف پذیری و سازش با عوامل بیرونی شد. در این مسیر پرتلاطم، انسان مدرن نیز به فکر ساخت ابزارهایی برای ایجاد تغییراتی هرچند جزئی در محیط زیست اطراف خود افتاد. روندی که کماکان ادامه دارد.
    کلیدواژگان: تغییرات اقلیمی محیطی، انسان مدرن، تطور فرهنگی، مراحل ایزوتوپ دریایی
  • حبیب بیابانگرد، ام البنین شهرکی، محمد بومری صفحه 213
    مخروط های آتشفشانی کوه بوبک و سیخ کوه در جنوب خاوری استان خراسان جنوبی و در شمال و جنوب باختری شهرستان نهبندان واقع شده اند. از دیدگاه تقسیم بندی زمین شناسی ساختاری ایران آنها متعلق به پهنه لوت می باشند. این مخروط ها عمدتا از سنگهای آذرین خروجی تراکی بازالت، و تراکی آندزیت تشکیل شده و دارای بافت غالب پورفیریتیک هستند. کانی های اصلی سازنده آنها پلاژیوکلاز، پیروکسن، الیوین، هورنبلند و بیوتیت و کانی های فرعی و ثانویه آنها کوارتز، سریسیت، اپیدوت، زئولیت و کلسیت می باشد. تعداد 12 نمونه ازسنگ های سالم منطقه جهت انجام تجزیه های شیمیایی عناصر اصلی و فرعی به ترتیب با روش های XRF و ICP انتخاب و به آزمایشگاه زرآزمای ماهان ارسال و مورد تجزیه قرار گرفتند. مشخصات ژئوشیمیایی این سنگها نشان می دهد که که ماگمای اولیه این سنگ ها تحول ازکلسیمی- قلیایی تا قلیایی دارد. در نمودارهای عنکبوتی، غنی شدگی از عناصر LREE و تهی شدگی از HREEبا الگوی موازی و مشابه دیده می شود که حاکی از منشا یکسان آنها می باشد. علاوه بر این، غنی شدگی در LILEوPbنسبت های عناصری Nb/ U و Ce/Pbنیز نشان دهنده ی آلودگی پوسته ای ماگمای سازنده سنگ های منطقه است. از طرفی نمودارهای ژئوشیمیایی، نسبت هایLa/Yb در مقابل Laو TiO2در مقابل Zrنشان دهنده روند تبلور تفریقی در نمونه ها است.همچنین این نمودارها نشان می دهند که ماگمای اولیه این سنگ ها، با منشا گوشته ای، دچار فرآیند تفریق و آلودگی پوسته ای شده است. نمودارهای تکتونوماگمایی، آنومالی منفی NbوTi و مشخصات ژئوشیمیایی در این سنگها حاکی از شکل گیری این آتشفشان ها در محیط فرورانشی است.
    کلیدواژگان: آلودگی پوسته ای، تکتونوماگمایی، فرورانش، کلسیمی، قلیایی، نهبندان
  • مرضیه مکرم، سعید نگهبان صفحه 225
    امروزه شناسایی لندفرم ها و طبقه بندی زمین مبتنی بر روش کارشناسی می باشد که به صورت دستی و با استفاده از عکس های هوایی و نقشه های توپوگرافی انجام می شود که روشی وقت گیر و دارای دقت کمی می باشد. از این رو استفاده از روش های نیمه اتوماتیک و اتوماتیک به منظور طبقه بندی لندفرم ها برای افزایش دقت و سرعت کار، ضروری به نظر می رسد. این پژوهش سعی دارد که به طبقه بندی لندفرم ها بر اساس الگوریتم شبکه های عصبی خودسازمانده (SOM)در حوضه آبخیز گاوخونی بپردازد. پژوهش از نوع تحلیل و توصیفی مبتنی بر روش های آماری، نرم افزار و میدانی است بدین صورت که که به منظور استفاده از الگوریتم SOMبرای طبقه بندی لندفرم ها از 6 پارامتر استفاده شد که شامل جهت (aspect)، ارتفاع (elevation)، شیب (slope)، پروفیل طولی و عرضی (plan ، profile) و انحنا (curvature) می باشد. برای این منظور ابتدا با استفاده از شاخص موقعیت توپوگرافی (TPI)، لندفرم های منطقه مورد مطالعه طبقه بندی شدند که از کلاس های لندفرم حاصل از TPIبه منظور آموزش مدل SOMاستفاده شد. در مرحله بعد از 50 نقطه به عنوان نمونه برای آموزش شبکه استفاده گردید. نتایج حاصل از طبقه بندی لندفرم ها با استفاده از الگوریتم SOMنشان داد که 6 خوشه (کلاس) در محدوده مورد مطالعه وجود دارد، به طوریکه خوشه 1 و 5 شامل لندفرم هایی است که در ارتفاعات زیاد قرار دارند و خوشه 3 شامل لندفرم هایی است که در کمترین ارتفاع واقع شده اند. بقیه خوشه ها شامل لندفرم هایی هستند که در ارتفاعات متوسط در حوضه آبخیز مورد مطالعه قرار دارند. بنابراین از الگوریتم فوق می توان به منظور پیش بینی لندفرم های منطقه مورد مطالعه استفاده کرد.
    کلیدواژگان: طبقه بندی لندفرم، شبکه های عصبی خودسازنده(SOM)، شاخص موقعیت توپوگرافی، حوضه آبخیز گاوخونی
  • محمدرضا کبریایی زاده، مجید میرزایی عطاابادی، عرفان خسروی صفحه 239
    برای نخستین بار بقایای فسیلی مهره داران پستاندار از نهشته های کواترنری بالایی منطقه زاویه در شمال ساوه معرفی و مورد بررسی سیستماتیک قرار گرفته اند. نمونه های مورد مطالعه شامل بقایای اسکلتی لگن کرگدن و اندام های حرکتی انتهایی و دندان های جدا شده اسب ها می باشند که در رسوبات دریاچه ای/ آواری زاویه یافت شده اند . این آثار بر اساس روش های استاندارد مورد اندازه گیری و توصیف قرار گرفته و برای تعیین قرابت و شناسایی دقیقتر به کمک آنالیزهای آماری دو متغیره با نمونه های مشابه امروزی و فسیل مقایسه گردیده اند. در نتیجه این تحقیق حضور کرگدن هایی از جنس احتمالیStephanorhinusو نیز اسبهای استنونیدی، احتمالا از گونه Equus hemionus، در کواترنری بالایی شمال ساوه گزارش می گردد.با توجه به این آثار فسیلی محیط دیرینه باز با پوشش درختی کوتاه یا بوته ای با آب و هوای نیمه مرطوب برای منطقه مورد مطالعه در نظر گرفته می شود.
    کلیدواژگان: مهره داران، پستانداران، فردسمان، فسیل، کواترنری، ساوه
  • میثم پریمی، محمد خانه باد، اسدالله محبوبی، رضا موسوی حرمی صفحه 255
    نهشته های ماسه ای از پدیده های زیبای ژئومرفولوژی مناطق بیابانی در جنوب دامغان هستند. هدف تحقیق مقایسه رسوب شناسی دو نوع از تپه های ماسه ای (نوع برخانی و نبکا) و بررسی خصوصیات مورفومتری آن ها در حاشیه کویر حاج علی قلی دامغان می باشد. طی برداشت صحرایی تعداد 27 رسوب ماسه ای از تپه های برخانی و 15 نمونه از تپه ماسه ای نوع نبکا برداشت گردید و همچنین هر دو نوع نبکای فعال و غیر فعال شناسایی شد. برای بررسی ارتباط آماری بین مولفه های مورفومتری تپه های ماسه ای برخانی طول قله، دامنه رو به باد و پشت به باد اندازه گیری شدند و همچنین برای بررسی پارامترهای مورفومتری تپه های ماسه ای نوع نبکا طول محورهای بلند، کوتاه و ارتفاع آن ها مورد اندازه گیری قرار گرفت. طی مطالعات آزمایشگاهی نمونه ها مورد آنالیز دانه سنجی قرارگرفته و پارامترهای آماری آن ها محاسبه شد. میانگین قطر دانه های تپه های ماسه ای برخانی برابر 435/2 فی (ماسه ریزدانه)، جور شدگی آن ها 530/0 فی (متوسط خوب جورشده)، کج شدگی 268/0- (به سمت ذرات دانه درشت کج شده) و شاخص کشیدگی 054/1 (به طور متوسط کشیده) است و همچنین میانگین قطر دانه های تپه ماسه ای نوع نبکاها برابر800/2 فی (ماسه ریزدانه)، جور شدگی آن ها 540/0 فی (متوسط خوب جورشده)، کج شدگی 070/0- (تقریبامتقارن) و شاخص کشیدگی 640/1 (خیلی کشیده) می باشد. نتایج به دست آمده از مورفومتری تپه های ماسه ای برخانی نشان می دهد که مولفه دامنه قله و پشت به باد بهترین ضریب همبستگی را نشان می دهند و برای به دست آوردن ارتفاع می توان از آن ها استفاده کرد. برای تپه های ماسه ای نوع نبکا رگرسیون خطی برای هر یک از متغیرهای مستقل در برابر متغیر وابسته به طول محور بلند محاسبه شد. با توجه به نتایج می توان گفت هر دو متغیر برای تعیین طول محور بلند مناسب می باشند.
    کلیدواژگان: کویر حاج علی قلی، مورفومتری، نبکا، تپه ماسه ای، رسوب شناسی
  • محمود داوودی، قاسم عزیزی، ولی الله مظفریان، رضا صفایی راد، داوود سلمانی صفحه 265
    امروزه مطالعات آب و هواشناسی دیرینه به دلیل کاربرد در مسایلی چون بررسی تغییرات آب و هوایی گذشته کره زمین، باستان شناسی، درک میزان تاثیر انسان بر تغییرات زیست محیطی، بازسازی داده های آب و هوایی طولانی مدت، شبیه سازی محیط های دیرینه یکی از محبوب ترین زمینه های مطالعاتی شده است. از جمله روش های متداول در مطالعات آب و هواشناسی دیرینه روش گرده شناسی است و از جمله مهم ترین ابزار این روش، اطلس های گرده شناسی هستند. در ایران مطالعات آب و هواشناسی دیرینه و به تبع آن روش گرده شناسی سابقه چندانی ندارد و کمبودهای زیادی در این رشته وجود دارد. از جمله این کمبودها می توان به نبود اطلس گرده های گیاهی ایران اشاره کرد. با توجه به این مسئله در این مقاله سعی شده است با ارایه گرده های گیاهی حوضه آبریز دریاچه پریشان، بخشی از این خلاء پر شود. بدین منظور گرده گیاهان منطقه و مغزه دریاچه پریشان استخراج شد. برای جداسازی گرده های گیاهی از نمونه رسوبی از روش استاندارد استخراج گرده های گیاهی استفاده شد. استفاده شد. در نهایت با تهیه اسلاید و کدگذاری آنها، توسط میکروسکوپ نوری گرده ها، شناسایی و عکسبرداری شدند. در مجموع تعداد 28 گرده شناسایی شد که مشخصات و تصویر هر گرده ارایه شده است.
    کلیدواژگان: دانه گرده، گرده شناسی، آب و هواشناسی دیرینه، دریاچه پریشان
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  • Elham Mojtahedin, Fatemeh Hadavi, Akram Pouresmaeil Page 181
    Coccolithophores are one of the main groups of marine phytoplankton playing key roles in the marine ecosystem as primary producers and in marine biogeochemistry. These organisms have gained considerable attention as they play a unique role in the global carbon cycle because of their combined effects on both the organic carbon and the carbonate pump. Although steady advances in research on coccoliths as biogeochemical agents and palaeontological proxies were obtained knowledge of the biology of these organisms has only progressed considerably in recent years. Calcareous nannoplanktons are one of the most important of phytoplankton for reconstruction of paleoinvironmentThe Persian Gulf Basin, is found between the Eurasian and the Arabian Plates. The Persian Gulf is described as a shallow marginal sea of the Indian Ocean that is located between the south western side of Iran and the Arabian Peninsula and south and southeastern side of Oman and the United Arab Emirates. Other countries that border the Persian Gulf basin include; Saudi Arabia, Qatar, Kuwait, Bahrain and Iraq. The Gulf extends a distance of 1000 km with an area of 240,000 square km. The Persian Gulf basin is a wedge-shaped foreland basin which lies beneath the western Zagros thrust and was created as a result of the collision between the Arabian and Eurasian plates. The Strait of Hormuz is the only link between the Gulf and the open water of Arabian Sea and Indian Ocean. It lies between Iran and a tiny separated territory of the Sultanate of Oman on the Arabian Peninsula. Measured along the median line, the Strait is about one hundred and four miles long but narrows to only twenty nautical miles at the northeastern end between Larak Island on the Iranian side, and the Quioins on the Omani side. The ability to reconstruct historical sea-surface salinity (SSS) patterns is essential to understanding past ocean circulation and climatic change. The calcareous nannoplankton is, as the most groups of marine organism, very sensitive to salinity fluctuations. The family Braarudosphaeraceae is one of the oldest extant coccolithophore families, it is distinguished by having a coccosphere formed of five-fold symmetric calcareous scales called pentaliths. The family has a long fossil record extending back to the Early Cretaceous. In the geological record, they show greater morphological variation in their pentaliths than in modern populations. Based on the morphology of the five segments forming a pentalith, six genera have been recognized in the Braarudosphaeraceae. Besides, although typical marine taxa, a few coccolithophores live in brackish waters and even in fresh ones. In the literature, Braarudosphaera bigelowii is often described as a species living in low-salinity coastal waters, since it is rarely recorded from the open oceanThe species Braarudosphaera bigelowii, a taxon confined mostly to shallow marine environment (first appearing in the Lower Cretaceous), is a good indicator of salinity fluctuations. Braarudosphaera bigelowii lives in the coastal areas, low salinity water and with entrancing of clastic materials. Low-salinity waters and unusual current conditions have also been put forward as a possible cause for past Braarudosphaerid blooms. The studies done on samples of the Persian Gulf, East of Strait of Hormuz and Oman Sea based on distribution of this species showed that in the study area frequency of this species very low and presence of this species in the western part of the Persian Gulf related to the entrance of fresh water to this area. the inflow of Arabian Sea waters occurs mainly in the northern part of the strait and forms a low-salinity wedge intruding westward into the gulf along the southern coast of Iran. Cyclonic circulation within the gulf carries these waters to the northwestern and shallow southeastern areas of the gulf where they are transformed to dense, saline waters which sink into the axial trough of the Persian Gulf and exit through the deepest part of the strait off northern Oman. A recent compilation of hydrographic data from the gulf indicates that the densest waters are formed in the northern gulf during winter, and that these waters propagate southward toward the Straits of Hormuz throughout the year. Slightly less dense, though saltier, waters are formed on the shallow southeastern shelves, which spill more intermittently into the deep gulf. While the general features of the exchange flow through the Straits of Hormuz are understood, the magnitude of the exchange is still poorly known because of large uncertainties in estimates of evaporation over the Persian Gulf. Evaporation and salinity in central part of the Persian Gulf are high and frequency of B.bigelowii is very low and finally in the East Stratit of Hormuz and Oman Sea the amount of salinity is high and in these parts B.bigelowii are rare.
    Keywords: Salinity, Persian Gulf, Oman Sea, Braarudosphaera bigelowii
  • Fahimeh Jajrami, Hamed Vahdati Nasab, Mohammad Ghamari Fatideh Page 191
    Modern human has been in constant struggle with climate and nature since its first appearance about 200 kya. Earth climate has been in continuous change since the mentioned time, most importantly the effect of glacial cycles were so severe. Facing with such endless environmental challenge, modern humans adopted several different ways to make themselves more adaptable, using elaborate culture was certainly among such ways. This relentless challenge with ever changing climate has had substantial impact on the Anatomically Modern Humans (AMH or Homo sapiens), which eventually along with some genetic changes forced them to become Behaviorally Modern Human or what we call: Homo sapiens sapiens. AMH had no option but to rely on its big brain and its creativity to come up with diverse solutions to compete with nature. Making more efficient tool kits, shelters, clothing, hunting, etc are among such innovations. This article reviews the human evolution story since the 115 kya (MIS 5e), which corresponds to the beginning of the last glacial cycle, to 11.5 kya, which is equal to the starting of Holocene. Right at the end of the MIS 6, the African central regions turned to the deserts. Such climatic change and loss of biomass forced new born human populations (early AMH) to leave these areas and move to either North or South seeking for new landscapes to survive.Evidences of modern humans in southern Tanzania and South Africa dated to 130 and 90 kya represent such dispersions. During the MIS 5e, which was an interglacial period (135-116 kya), proper climatic conditions reopened the central African regions to the human populations. On the other hand, such ideal environmental situation and abundance of food might have been responsible for the proliferations of the human populations, obliging some of them to leave Africa for the Levant. Presence of archaeological sites of Skhul and Qafzeh dates to 119-85 kya is the indicator of these populations. Throughout the whole MIS 5 glacial cycles numerous contractions and expansions of human population ranges took place in Africa and Eurasia. It seems that dense human populations in the reservoirs such as alongside of the beaches (e.g., South Africa, Levant and North Africa) demanded more complexity in the societies and more diverse ways of acquiring foods. Human response to such forces was mostly based on using different methods that we call them culture. During the last stages of the glacial period (30-11.6 kya) the sea level dropped rapidly. That provided human populations with an immense opportunity to expand to the regions they had never walked in such as America and South East Asia islands. Human cultural evolutionary process had two aspects of conscious and unconscious. Through most of the human evolutionary history, this was the unconscious aspect which played a significant role. At each age humans did only minor changes and small insignificant innovations such as change in the hunting methods, storage, clothing, building shelters, etc. Such small changes through cumulative process led to what we see it today as elaborate complex cultures around the world. While some of these modern cultures appear extremely complicated, we must not forget that the root for all such modern, complicated cultures go back to the time that humans started to face with nature and its protégé such as climatic changes and environmental unrest using their brains rather than their bodies.
    Keywords: Climatic Changes, Modern Human, Cultural Evolution, Oxygen Isotope Stagesnguage
  • Habib Biabangard, Ummolbanin Shahraki, Mohammad Boomari Page 213
    Kuh-Bubak and Sikh-kuh volcanic cones are located in Southeast of South Khorasan province, north and Southwest Nehbandan city. Based on structural geology classification of Iran, these volcanos are belonging to Lut zone. These cones are composed mainly of Thrachybasalte and Thrachyandesite composition rocks and they are dominant porphyric texture. These rocks have plagioclase, pyroxene, olivine, hornblende and biotite as main minerals and quartze, sericite, epidote, zeolite and calcite is secondary minerals. Twelve fresh rock samples are selected for chemical analysis and then send to the Zrazmay Mahan laboratory were analyzed major and trace elements with XRF and ICP methods respectively. Geochemical characteristics of these rocks show that the primary magma formed these rocks have changes from Calk-alkaline to alkaline. In spider diagrams observed that LREE enrichment and HREE depletion, similar pattern can be seen in parallel and indicated their origin is the same. In addition, enrichment in LILE, and Pb, ratio elements of Nb/U and Ce/Pb indicates that they are contamination with crustal rocks. On the other hand, geochemical diagrams La/Yb versus La and Zr versus TiO2 indicating fractional crystallization process are happen in these rocks. Geochemical various diagrams show that fractionation and crustal contamination has affected on the primary magma. Nb and Ti negative anomalies and geochemical properties indicating that these volcanoes are belonging to subduction zone.
    Keywords: Crustal contamination, Tectono, magmatic, Subduction, Calk, alkaline, Nehbandan
  • Marziyeh Mokaram, Saeed Negahban Page 225
    Introduction system of landform classification for soil mapping has been desired by soil scientists in Canada for a long time. The Canada Soil Survey Committee (CSSC) adopted a system at a meeting held at the University of Guelph in February 1976. Many aspects of the system came from mapping schemes used by the Geological Survey of Canada for mapping surficial geology. The system also embodies concepts developed initially by R.J. Fulton and later by N.F. Alley while doing terrain mapping in British Columbia. However, the needs of the soil scientist for a terrain or landform classification system are not necessarily compatible with those of the geologist. Relief analysis is a tool to analyse a landscape based on a Digital Elevation Model (DEM). One of the simplest parameters might be the elevation itself, or slope or the exposition of a given point in a landscape. Moore et al. (1991) state that the spatial distribution of topographic attributes can often be used as an indirect measure of the spatial variability of hydrological, geomorphologic and biological processes. The advantage compared to other information such as soil parameters or biomass production estimates is based on the relatively simple and fast techniques to model processes in large areas and the complex spatial patterns of environmental systems as seen by Moore et al. (1993b). Another relief parameter relevant for this work is landforms or relief units. Each of these contains certain characteristic physical, chemical, and biological processes and parameters (see Dehn et al., 2001). Milne (1936) was one of the first scientists, who recognised the catena principle of soil formation in a hilly terrain (Ruhe, 1960).Material And Methods Materials are classified according to their essential properties within a general framework of their mode of formation. Four groups (components) of materials have been recognized to facilitate further characterization of the texture and the surface expression of the materials. They are unconsolidated mineral, organic, consolidated, and ice components. These groups and the classes established within them are presented below. This research is trying to classify landforms on the basis of self-organizing neural network algorithm (SOM) in the watershed Gavkhoni pay to use the SOM algorithm is used to classify landforms of 6 parameters that includes orientation (aspect), height (elevation), tilt (slope), the longitudinal and transverse profiles (plan, profile) and curvature (curvature) is.Generally, The aim ofthisstudyis theclassificationof landformsin thebasinGavkhoni. Classification methodstohelpmajorlandformsvisitthe field, usingtopographic mapsandaerial photos, which requires experience. Theautomaticmethodbased ondigital elevation model(DEM)can beusedto classifylandformsBasinGavkhoni.Result And discussion The results of the classification of landforms using SOM algorithm showed that 6 cluster (class) in the study area there as clusters 1 and 5 includes landforms that are at high altitudes and cluster 3 includes landforms that are located at the lowest height. The rest of the cluster, including the landforms that the average height of the watershed studied. So the algorithm can be used to predict the landforms of the study area. The results showed that6isthe maximumdatain SOM algorithm. Also, at leastinthishexdatais zero, which indicates thatthere areno numbersinthislocation. The results ofprincipal component analysisshowedhigh densityanddistributiondata. According to theabove resultsshow thatthelandformsinput datain Figure6 classeshave beendistributedin the study area.Conclusion In this research was used SOM (SOM) to classify landforms. In order to use algorithms for classification of landforms of 6 parameters were used in the watershed Gavkhoni , The results of the classification of landforms using SOM algorithm showed that 6 cluster (class) in the study area ther. as clusters 1 and 5 includes landforms that are at high altitudes and cluster 3 includes landforms that are located at the lowest height. While cluster 3 includes landforms that are the lowest height. The rest of the cluster, including the landforms that the average height of the watershed studied. In general, using the SOM algorithm can be 6 classes to classify landforms in the study area predicted. Using the results of the SOM algorithm to manage watershed management approaches should be considered 6.
    Keywords: Classification of landforms, self, organizing neural networks (SOM), topographic position index (TPI), Gavkhoni Basin
  • Mohammadreza Kebriayi Zadeh, Majid Mirzayi Ataabadi, Erfan Khosravi Page 239
    Fossil vertebrates from quaternary are little known in Iran. This is unfortunately the case for vertebrate fossils from other eras as well. Never the less, elephantidae fossil remains are among the first quaternary fossil vertebrates to be reported from Iran (Farchad and Sahabi 1961). In the recent years more remains of fossil mammals have been reported especially from cave deposits of Late Quaternary in different parts of country, mostly from the Zagros ranges (Biglari et al. 2009, Mashkour et al. 2009). Also, Pleistocene remains of mammals, including Rhinocerotidae, have been reported from eastern Iran (Hashemi and Darvish 2007). Here we report the first fossil mammals from mainly lake and alluvial deposits of Zavyeh area, north of Saveh in central Iran.
    The Quaternary lake deposits in the study area have been recently studied in detail (Djamali et al. 2006). The former studies in this area failed to distinguish these deposits as an independent unit from the well known formations in the region. During the geological and sedimentological surveys by Djamali, the first vertebrate fossils were collected. Further investigations by authors lead to the discovery of several more remains.
    This study is thus based on postcranial and dental remains of fossil Perissodactyla. These are parts of pelvis, including Ilium, pubis and sacrum of a large vertebrate resembling rhinos. Other fossils belongs to equids and consists of metapodials or leg and arm bones (metatarsus and metacarpus) and first phalanges (toe bones), as well as a few lower and upper dentitions. Provenance of equid remains is not as well known as the rhino material. Therefore, it is possible that they belong to different levels from the study area. The lower teeth belong to the molar row (m1-m3) and the upper tooth is a fourth premolar (P4). This material has been described and measured according to standard international protocols (Table 1). The measurements have been used in bivariate analysis and comparison of fossil material with extinct and extant similar species in order to identify the fossil material better (Fig. 6).
    Based on the size and characteristics of the pelvis bones, they can be referred to rhinoceratidae. To better categorize these fossil remains, the length and width of acetabulum of Zavyeh has been compared with several fossils and extant species, including rhinos and other mammals (Table 2 and Fig. 6A). The graph of acetabulum dimensions clearly shows the association of Zavyeh fossil material with other rhinos, ruling out attribution of these specimens to other families. Zavyeh rhino is similar in size to present day species like the African rhinos as well as fossil material of Stephanorhinus genus. Since Stephanorhinus is the most abundant and prominent fossil rhino of the interglacial Quaternary, We believe that our fossil material is most likely belonging to this genus and an indefinable species.
    The fossil equids are clearly belonging to Equus and based on the dental morphology they are better grouped within stenonid horses (Fig. 5). Their main characteristic is the V shaped entoflexid morphology on their lower teeth. To identify the species, we compared both dental and skeletal material with several extant and fossil equids. The dental comparisons show that the upper premolar tooth is close in size to stenonid species like present day grevyi zebras and hemiones like E. hemiones. However, the Zavyeh material is slightly larger than the mentioned species, reaching the lower size distribution of true horses. The Metapodial graphs show that these fossil materials are smaller than many caballoid horses. They are better suited among stenonids, like African zebras and E. hemionus from different areas (Fig. 6). Therefore, the equid fossils from Zavyeh are probably remains of E. hemionus This conclusion is mainly based on the wide distribution of this species in Quaternary and also their continuous presence in Iran during Holocene and present time. However, presence of other equid species cannot be excluded from this locality
    In conclusion, presence of fossil rhinos, like Stephanorhinus, and equids, such as E. hemionus, are reported for the first time from Late Quaternary of Zavyeh, north of Saveh. The presence of rhinos in Late Quaternary of Iran, as was previously reported from eastern and central Iran (Hashemi and Darvish 2006, Biglari et al. 2009, Mashkour et al. 2009) is now documented to larger extent. This increases our data about presence of these peculiar animals in Iran. The equids should be investigated further to confirm their exact provenance and their possible relation with present day wild asses (E. hemionus onager) of the country. As far as the ancient environment is concerned, these fossils (along with other evidence) show the existence of favorable climatic conditions with more rain and less evaporation during the Late Quaternary of (north and west) Iran (Kehl 2009).
    Keywords: fossil, mammals, perissodactyls, quaternary, Saveh, vertebrates
  • Meysam Parimi, Mohammad Khanebaad, Asadollah Mahboubi, Reza Muosavi Harami Page 255
    Introduction Barchan dunes and nebkhas are great geomorphologic phenomena of desert areas in south of Damghan. The purpose of this study is to analyze the sedimentology of sand dunes and nebkha deposits in the Haj Aligholi Desert. More than two-thirds of the Iran's area is arid and semi-arid land. The diversity of flora is limited in these areas because of low humidity. This causes the wind to easily effect on the surface of these lands and carries the sand size and finer grains and deposited in another place. Barchan sand dunes are the most abundant type of sand dunes in the Haj Aligholi Desert. Dispersed vegetation plays an important role in sediment transport and nebkhas formation in this area. Nebkhas or sand dunes are formed usually in hot and humid and semi-arid regions and widespread where the sand can be trapped by vegetation. The study area is located about 35km south of Damghan in 54°, 10' to 54°, 30' E longitude and 35°, 45' to 36°, 00' N latitude. Material and Methods 27 and 15 samples were collected respectively from the sand dunes and nebkhas to determine the sedimentary parameters. Grain size analysis was carried out using dry sieve with a set of 0.5 phi screens for measurement of statistical parameters (mean, median, sorting, skewness and kurtosis). For morphometric investigation the parameters of sand dunes (lee side, stoss side and crest) and nebkhas (long axis, short axis and height length) were measured. Result and Discussion The mean diameter of the grain size, the average of sorting, skewness and kurtosis in the sand dunes are about 2.435 phi (fine sand), 0.530 phi (moderately well sorted), -0.268 (coarse skewed) and 1.054 (mesokurtic), respectively. The mean diameter of the grain size, sorting, skewness and kurtosis in the nebkhas are about 2.800 phi (fine sand), 0.540 phi (moderately well sorted), -0.070 (near symmetrical) and 1.640 (very leptokurtic), respectively. The comparison between the index of kurtosis and sorting show that with increasing of the grain's kurtosis, the grain's sorting increased. After doing regression for each of the independent variables versus the dependent variable to height was calculated. The results show that the attribution of the stoss side and the crest show the best correlation. Therefore, with stoss side and crest components, we can calculate the height of sand dunes from the high-resolution images satellite. To compare the relationship between the longaxis's length and short axis's length, as well as the long axis's length and height of the nebkhas obtained the regression equation in the study area. The results show that this both variable are suitable for measured of long axis in the nebkhas. In this study, both types of nebkhas (active and passive) were identified that cause of the deactivation of them is dropping in the level of groundwater, which its witness is embayment and cracking on the surface of the ground. Due to the prevailing of northwest wind seems to be the accumulation of sediments at this area is closely related to the groundwater table and soil moisture of this region. Conclusion The average of sorting calculated for sediments of sand dunes and nebkhas was moderately well sorted showing two source for sediments (bimodal) and it cause to decrease the amount of sorting. The average of skewness of sand grains skewed to the coarse grains. We can found type movement of sediments that it is saltation. Northwest wind that blowing in study area controlled sand dunes type and position and cause of this claim is morphology and situation of sand dunes. The results of regression revealed that the attribution of the stoss side and the Crest in sand dunes and and also in nebkha dunes the attribution of the short axis and height show the best correlation. In the study area both nebkha (active and passive) found which phenomena annihilator of nebkha is falling groundwater level that it's increasing the desertification.
    Keywords: Haj Aligholi desert, morhpometry, nebkha, sand dune, sedimentology
  • Mahmoud Davoodi, Ghasem Azizi, Valiollah Mozaffarian, Reza Safayi Rad, Davood Salmani Page 265
    Introduction Nowadays, paleoclimatology studies are considered as one of the most popular study fields, for they can be applied for various subjects like the study of past climatic changes of the earth, archeology, the effects of human beings on environment, rebuilding of long-term climatic data and ecosystem simulation. Climate change on all aspects has serious impacts on natural and human life. Natural variability is an inherent feature of climate that happens in short time and long time; As the Earth's climate and ecological conditions during the various geological changes and fluctuations very strong. Knowledge of weather and its patterns over long periods of time will help to determine the future climate. Thus, climate experts and environmental scientists have shown a lot of attention to paleoclimatology and ecology past changes. Through studies of paleoclimatology can reconstruct climate elements of past and predict the pattern of future climate. In fact, to predict the future climate the long-term data is needed; while direct measurement instrument of meteorological data only able to provide a picture of the climate of the past few decades. Therefore, to surmount the direct measurement of poverty, paleoclimatologist must use indirect evidence to discover and reconstruct the long time data. Palynology is one of the most popular methods in metrological studies and palynology atlases are the most significant tools of this method. As a matter of fact, the annals of paleoclimatology studies and palynology studies in Iran is not so rich, leading to numerous shortages in the field like lack of pollen atlas of Iran. As a result, this study aims at filling this gap by introducing the plant pollens of Parishan Lake basin.Material and Methods Two field studies were done in April and June 2013 to conduct the present research. Searching on the basin of Parishan Lake, the vegetation samples were assembled, dried, and transferred to the Botanical National Park of Iran. Then, the samples were transferred to paleoclimatology laboratory of Geography Faculty in University of Tehran in which they sampled the plants’ flowers. In the second step of sampling, a core, measuring about 8.5 m, was taken from the floor of Parishan Lake and its pollens were investigated with intervals of 10 cm. Moore et al. (1991), Erdtman (1952), Faegri and Inversin (1975) methods were used to separate the pollens. Then, Silicon oil 2000 was added to avoid oxidization. Besides, they were put in furnaces with 500C for 24 hours to be dried. Making slides and codifying by microscope, the pollens were recognized and photographed. Official sites and authoritative books and articles were applied to identify the pollens of the core (Faegri and Iversen, 1975; Kremp, 1965; Punt et al., 1994; Hesse et al., 2009; Roubik, 2003; Demske, 2013; Vafadar et al., 2010; Binka, 2003; Behboodi, 2005; Palynology Websites of Australia, Arizona, and San Francisco). Moreover, 5 pollens of each type were measured and the average was considered as the normal size of the pollen.Results The findings reveal that there are 28 pollens in the basin of Parishan Lake including 4 tree pollens, oak, pistachios, almond and olive, 2 water plant pollens of Cyperaceae and Sparganium sp., while the rest are shrubs and herbaceous plants. Their features, including polar axis, equatorial axis, and forms, are presented in Table 1, while equatorial view, polar view, the walls and the level decorations are shown in Figures 2- 10. Pollen size is not fixed and can be smaller or larger than the models listed. The size listed is the average number of groups of any kind.Conclusion As a matter of fact, lack of plant pollen atlas and fossil pollens of Iran has disturbed paleoclimatology studies based on palynology. In fact, the most significant advantage of identifying past climatic changes based on palynology is the recognition of much more pollens in the sediments. However, lacks of pollen articles and pollen atlases have affected this subject. As a result, this research aims to study the plant pollens of Parishan Lake basin which were assembled, prepared, recognized, and photographed by scientific methods. The final output revealed that there are 28 plant pollens including tree pollens, shrub pollens, herbaceous pollens and water plant pollens. Several photos of each pollen are presented to help the researchers to recognize the pollens. These photos were taken from different views like polar view, equator view, pollen wall, level decoration and size.
    Keywords: fossil pollen, palynology, paleoclimatology, Parishan Lake