فهرست مطالب

  • سال سوم شماره 2 (پیاپی 6، پاییز و زمستان 1394)
  • تاریخ انتشار: 1394/12/29
  • تعداد عناوین: 8
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  • فرح جلیلی، فاطمه هادوی*، بهنام رحیمی، احمد رضا خزاعی صفحات 132-143

    در پژوهش حاضر، زیست چینه نگاری نهشته های فیلیشویید افضل آباد (شمال بیرجند) براساس نانوفسیل های آهکی مورد بررسی قرار گرفته است. این فسیل ها به دلیل فراوانی نسبی، محدوده چینه شناسی کوتاه و گسترش جغرافیایی وسیع، ابزار مناسبی برای تقسیم بندی زیست چینه ای هستند. در فیلیشوییدهای افضل آباد، 21 جنس و 56 گونه از نانوفسیل های آهکی شناسایی گردید. بر این اساس، در پایین ترین بخش توالی زون زیستی NP11 و در بالاترین قسمت توالی زون زیستی NP19 از زون بندی (Martini (1971 تعیین شد. بر اساس این زون های زیستی، سن ضخامت مورد مطالعه در برش افضل آباد ائوسن پیشین تا ائوسن پسین (ایپرزین تا پریابونین) پیشنهاد می شود.

    کلیدواژگان: نانواستراتیگرافی، فیلیشویید، افضلآباد، بیرجند
  • جهان بخش دانشیان*، الهام کیوانی صفحات 144-161

    به منظور مطالعه روزن داران و چینه نگاری زیستی نهشته های سازند قم در ناحیه دلیجان، برش چینه شناسی فرنق در جنوب شرق دلیجان انتخاب شد. برش مذکور با 558 متر ضخامت، عمدتا شامل سنگ آهک و مارن است که با ناپیوستگی فرسایشی روی نهشته های سازند قرمز زیرین و در زیر نهشته های سازند قرمز بالایی قرار گرفته است. بررسی و مطالعه 210 نمونه برداشت شده (شامل 151 نمونه سخت و 59 نمونه نرم) از نهشته ها، به شناسایی 38 جنس و 54 گونه از روزن داران کف زی و 7 جنس و 10 گونه از روزن داران شناور منجر شد. بر اساس حضور گونه های شاخص و شباهت با فونای سازند آسماری، نهشته های سازند قم در این برش با بایوزون های Borelis melo group - Meandropsina iranica Assemblage Zone (بایوزون شماره 1) و Miogypsinoides - Archaias - Valvulinid Assemblage Zone (بایوزون شماره 2) در نوشته Adams & Bourgeois (1967) قابل مقایسه اند. سن پیشنهادی برای این برش میوسن پیشین (اکیتانین تا بوردیگالین) است به طوری که حدود 15 متر از نهشته ها در پایین مربوط به اکیتانین و 543 متر بالا مربوط به بوردیگالین می باشند.

    کلیدواژگان: سازند قم، روزنداران، چینه نگاری زیستی، فرنق، میوس پیشی
  • جواد سعادت نژاد* صفحات 162-171

    به منظور مطالعه و معرفی ماکروفسیل های گیاهی سازند کرج (ائوسن)، منطقه ارنگه (ناودیس ارنگه) واقع در شمال باختری تهران مورد بررسی قرار گرفت و نمونه هایی از نهانزادان آوندی شامل دم اسبیان (جنس Equisetum)، پنجه گرگیان (راسته Lycopodiales)، برگ های خرد شده گیاهان نهان دانه تک لپه ای از خانواده Cyperaceae (راسته Poales)، شاخه های جوان حامل برگ و کلاف گل های تک جنسی نر از گیاهان نهان دانه دو لپه ای از خانواده Casuarinaceae (راسته Fagales)، اندام زایای گیاهان نهان دانه دولپه ای (به احتمال میوه) و ریزوم های نهان دانگان تک لپه ای از منطقه به دست آمدند. در مطالعه پیش رو، ماکروفسیل های گیاهی از سازند کرج، ماکروفسیل های گیاهی دو راسته Poales و Fagales از ایران، ماکروفسیل های گیاهی از دو شاخه اسفنوفیتا (دم اسبیان) و لیکوپودیوفیت ها از رسوبات سنوزوئیک ایران و خانواده Casuarinaceae از منطقه ای خارج از گندوانا برای نخستین بار گزارش می شوند. همچنین آب و هوای زمان زیست گیاهان یافت شده از منطقه، گرم و مرطوب و محیط زیست آن ها نیز منطقه ای پرآب و یا حاوی خاک های نمناک و مرطوب پیشنهاد می شود. نمونه های یافت شده همگی از رسوبات بخش شیل کندوان (ائوسن میانی) و ارتفاعات شمال خاوری روستای جی برداشت شده است.

    کلیدواژگان: ماکروفسیلهای گیاهی، ارنگه، سازند کرج، ائوسن میانی، البرز مرکزی
  • فاطمه هادوی*، سمیه سنجری، محسن علامه، مرضیه نطقی صفحات 172-181

    به منظور بررسی سازند آب دراز در حوضه کپه داغ، استراکدهای برش مزدوران مورد مطالعه قرار گرفته است. سنگ شناسی عمده سازند در این برش از شیل و مارن همراه با سه افق سنگ آهک گل سفیدی تشکیل شده است. نهشته های مطالعه شده حاوی بقایای استراکدها است که بررسی این میکروفسیل ها به شناسایی 40 گونه، 16جنس و چهار پهنه زیستی منجر شده است. بر اساس استراکدها و انطباق آن ها با نانوفسیل های آهکی شناسایی شده در این برش، سن سازند آب دراز سانتونین پسین تا آبتدای کامپانین پسین تعیین گردید.

    کلیدواژگان: استراکد، آبدراز، کپه داغ، مزدوران
  • حسین غلام علیان*، محمد گودرزی، فرشاد سالاری پور صفحات 182-197

    در این پژوهش خارداران موجود در نهشته های آلبین سنومانین (سازند کژدمی) در برش کوه گورگن، شمال نورآباد، مورد بررسی قرار گرفته اند. تعداد هشت گونه متعلق به پنج جنس Anorthopygus orbicularis، Cidaris (Dorocidaris) taouzensis، Coenholectypusplanatus، Macraster douvillei، Macraster longesulcatus، Macraster obtritus، Pedinopsis aff. sinaica و Toxaster granosus شناسایی شده اند که از این میان گونه Cidaris (Dorocidaris) taouzensis در این مقاله برای اولین بار از ایران گزارش می شود. حضور گونه یاد شده، سن سنومانین را برای راس سازند کژدمی در برش کوه گورگن ثابت می کند.

    کلیدواژگان: خارداران، سازند کژدمی، کرتاسه، آلبین، سنومانین، نورآباد، کوه گورگن
  • ابراهیم محمدی*، حامد عامری، مهدی قائدی، محمدرضا وزیری، رضا صادقی، محمد داستا ن پور صفحات 198-219

    به منظور بررسی سازند قم در بخش جنوب شرقی حوضه پس کمان قم، نهشته های این سازند در شمال شرقی نطنز مورد مطالعه قرار گرفتند.این نهشته ها با 330 متر ضخامت یکی از صخره سازترین برونزدهای سازند قم بوده و از نظر سنگ شناسی شامل دو بخش پایینی با 210 متر ضخامت مشتمل بر سنگ آهک های متوسط تا ضخیم لایه و توده ای، سنگ آهک های ریفی و شیل و بخش بالایی با 120 متر ضخامت دربردارنده سنگ آهک های متوسط تا ضخیم لایه و مارن می باشند. برونزدهای سازند قم در ناحیه شمال شرقی نطنز با ناپیوستگی روی سنگ های آتش فشانی ائوسن، قرار گرفته و در انتها توسط آبرفت پوشیده شده اند. با توجه به روزن داران شناسایی شده و توزیع عمودی آن ها، توالی مورد مطالعه دارای سن روپلین؟ شاتین آکیتانین می باشد. برداشت و مطالعه 166 نمونه همراه با مشاهدات صحرایی به شناسایی 9 ریزرخساره منجر گردید. با توجه به مطالعات انجام شده، بخش پایینی برش مورد مطالعه عمدتا در محیط های لاگونی و بخش بالایی کاملا در دریای باز نهشته شده است. در انتهای رسوب گذاری بخش پایینی، دو عامل افزایش عمق (که توسط فونای محیط های عمیق تر مشخص شده اند) و ورود مواد کلوئیدی (که با فراوانی رخساره های مارنی مشخص شده است) سبب جلوگیری از رشد مرجان ها شده است. بر اساس شواهد صحرایی و ریزرخساره های شناسایی شده، سازند قم در شمال شرقی نطنز بر روی یک رمپ نهشته است. حضور گسترده روزن داران کف زی بزرگ و ریف های مرجانی نشانگر ته نشینی در آب های گرمسیری می باشد.

    کلیدواژگان: سازند قم، اعنگومنوسن، ریف مرجانی، رمپ، حوضه پسکمان قم
  • فاطمه واعظ *، شهرام نام جو صفحات 220-243

    سازند هجدک در منطقه کوچکعلی، جنوب باختر طبس از گسترش خوبی برخوردار است. این سازند عمدتا از شیل های خاکستری تیره، سیلت سنگ و ماسه سنگ با میان لایه هایی از رگه های زغال سنگ تشکیل می شود. ماکروفسیل های گیاهی این سازند از چاه اکتشافی شماره 169 جمع آوری و مورد مطالعه قرار گرفت. تعداد 32 گونه ماکروفسیل گیاهی متعلق به 19 جنس از راسته های مختلف Bennettitales، Caytoniales، Cycadales، Dicksoniales، Equisetales، Ginkgoales و Pinales مورد شناسایی قرار گرفتند. با توجه به حضور گونه های شاخص Coniopteris hymenophylloides، Klukia exilis، Nilssonia macrophylla و Elatides thomasii سن آالنین باژوسین برای این مجموعه فسیلی در نظر گرفته می شود. یک بایو زون تجمعی به نام Klukia exilis-Nilssonia macrophylla Assemblage zone و چهار زیر بایو زون به ترتیب از پایین به بالا به نام های Sagenopteris nilssoniana-Equisetites columnaris Concurrent Range zone، Equisetites beanii-Ptilophyllum harrisianum Concurrent Range zone، Ginkgoites huttonii Taxon Range zone و Ferizianopteris undulata-Coniopteris hymenophylloides Assemblage zone در این سازند تعیین گردید. بایو زون های سازند هجدک در منطقه کوچکعلی طبس با سایر بایو زون های هم ارز در منطقه مزینو (بلوک طبس)، سازند دانسیرت در مناطق بلده و رودبارک (کوهستان های البرز مرکزی) و سازند بازه حوض در برش الگو (جنوب مشهد، کوهستان بینالود) مورد مقایسه و تطبیق قرار گرفت. با توجه به فراوانی سرخس ها و سیکادال ها در این مکان، آب و هوای مرطوب و نیمه گرمسیری در این بازه زمانی غلبه داشته است.

    کلیدواژگان: ماکروفسیل گیاهی، زیست چینه نگار، سازند هجدک، کوچکعلی شمالی، طبس، آب و هوا
  • مهدی هادی*، حسین مصدق، نصرالله عباسی صفحات 244-256

    این مطالعه بر روی دیرینه بوم شناسی بستر دریای ائوسن در البرز غربی بر اساس گرادیان عمق سنجی متمرکز است. ترکیبی از عوامل محیطی نظیر انرژی آب، شدت نور و سدهای فیزیکی (روزن داران قشرساز) از مهم ترین عوامل محیطی بودند که در ریخت شناسی و رفتارهای هیدرودینامیکی روزن داران کف زی بزرگ به شدت انعکاس یافتند. از این رو شواهد دیرینه بوم شناختی بستر بر اساس چهار تجمع از روزن داران کف زی بزرگ نشانگر یک دریای کم عمق (کمتر از 40 تا 100 متر) ائوسن در پهنه نوری تحت تاثیر انرژی متوسط جریانات و امواج می باشد.

    کلیدواژگان: البرز غربی، ائوسن، روزنداران کفزی بزرگ، عمق سنجی، کوهیای سلطانیه
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  • Fatemeh Hadavi* Pages 132-143
    Introduction

    The studied section is located in east Iran, Lut block (a part of flysch basin east of Iran) and west of Afzalabad (north Birjand city). The mentioned flyschoids are more than 4200 m thick. The studied section consists of two units including 200 m shale and sandstone of Paleocene age (abbreviated as Pef in the geological map) and 300 m of shale and sandstone, marl, sandstone and limestone of Eocene (as Ef in the geological map).

    Material and Methods

    290 samples were taken from this sequence. The upper and lower parts of the mentioned sequence were sampled over a smaller distance. In order to avoid weathering, samples were often taken from a depth of 50cm. Most of the samples were from shale and marl. Most samples were prepared using smear slide method and others by gravity method. Nannofossils were studied using Polarizing Light Microscope Olympus (BH2 model) in PPL and XPL lights, and most of them were photographed.

    Discussion

    In order to determination calcareous nannofossils of this sequence, (Romein, 1979; Perch-Nielsen, 1985; Bown & Young, 1985) reports were used. According to these studies, 21 genera and 56 species of calcareous nannofossils have been identified in the mentioned sequence. Martini, 1971 biozonation is amongst common biozonations for Paleogene and Neogene. Recently other complementary studies were conducted by Agnini et al., 2014. They have adapted their biozonation to that made by Martini, 1971 using some minor changes. Biozonations introduced in this sequence include:Discoaster binodosus Zone (NP11)
    This biozone has been defined based on Martini, 1971 biozonation from the last appearance of Tribrachiatus contortus to the first appearance of Discoaster lodoensis. The age of this biozone is early Eocene (Ypresian). It is worth mentioning that Agnini et al., 2014 have defined their CNE3 biozone, which is started a bit before NP11, at lower edge by the first appearance of Tribrachiatus orthostylus and its upper edge exactly matches that of NP11. In our studied sequence the first appearance of Tribrachiatus orthostylus occurs at the base of the sequence and the first appearance of Discoaster lodoensis was seen 230 m from the sequence base which is the upper boundary of biozone NP11 of Martini, 1971. The age of this biozone is early Eocene (Ypresian).
    Tribrachiathus Orthostylus ZONE (NP12)
    According to Martini, 1971 biozonation, this biozone continues from the first appearance of Discoaster lodoensis to the last appearance of Tribrachiatus orthostylus. The age of this biozone is early Eocene (Periabonian). In the studied sequence the first appearance of Discoaster lodoensis was seen as the base of NP12 biozone and the upper boundary of this biozone was determined based on the last appearance of Tribrachiatus orthostylus.
    Isthmolithus recurvus ZONE (NP19)
    Based on NP19 biozone (Martinin, 1971), the lower boundary of this biozone in this sequence was also determined by the first appearance of Istmolithus recurvus and the upper boundary of this biozone was determined by the first appearance of Sphnolithus pseudoradians. The age of this biozone is Late Eocene (Priabonian). The thickness of this biozone is 100 m in Afzalabad sequence.

    Conclusion

    In Afzalabad flyschoid (north Birjand), 21 genera and 56 species of calcareous nannofossils were identified. Based on the identified species, NP11 and NP12 biozons (Martini, 1971) were identified for lower part of this sequence which nearly matches CNE3 and CNE4 biozons from Agnini et al., 2014 biozonation. In the upper part of the studied sequence NP19 biozone (Martini, 1971) was determined. Agnini et al., 2014 biozonation measures were not seen in this section. According to the identified biozons, the age of studied sequence, Ypresian (early Eocene) to Periabonian (Late Eocene) is suggested for the studied thickness. Considering the presence of NP11 biozone in the upper part of Pef and the lower part of Ef, the pass of mentioned units is continuous and gradual.
    Keywords: Nannostratigraphy; Flyschoid; Afzalabad; Birjand.
    References
    Agnini, C., Fornaciari, E., Raffi, I., Catanzariti, R., Palike, H., Backman, J., & Rio, D., 2014. Biozonation and biochronology of Paleogene calcareous nannofossils from low and middle latitudes. Newsletters on Stratigraphy, 47 (2): 131-181.
    Martini, E., 1971. Standard Tertiary and Quaternary Calcareous Nannoplankton Zonation. In: Farinacci, A., (ed.), Proceeding of 2nd International Conference of Planktonic Microfossils, Roma, 2: 739-785.
    Perch-Nielsen, K., 1985. Cenozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.H., & Perch-Nielsen, K., (eds.), Plankton Stratigraphy, Cambridge University Press, 427-554.
    Romein, A.J.T., 1979. Lineagesin early Paleogene Calcareous Nannoplankton Utchret Microplaentol. Utrecht micropaleontological bulletins, 22: 1-230.

    Keywords: Nannostratigraphy, Flyschoid, Afzalabad, Birjand
  • Jahanbakhsh Daneshian* Pages 144-161
    Introduction

    The Qom Formation is known with layers of shallow water limestone and marl which its special geological features and distinct color distinguish it from the Lower Red and Upper Red formations. This formation were deposited in back-arc and for-arc basins and is one of the lithostratigraphic units of Central Iran Zone with Oligocene to Miocene age that shows the last transgression in central Iran (Rahimzadeh, 1994). This formation is diachronous in areas which have outcrops and the changes of age is significant considering the time of sea transgression and the beginning of sedimentary cycles. The Qom Formation maybe shows part of Rupelian, Chattian, Aquitanian, Burdigalian and even Tortonian (Aghanabati, 2004). According to Berberian (1983), generation of sedimentary basin of the Qom Formation has been indication subduction of Tethys oceanic crust beneath central Iran by opening back-arc and associated with deposition of marine sediments of the Qom Formation and alkaline volcanic processes. Changes of  age and thickness in the Qom deposits of adjacent areas of the studied section such as Aranjan and Doreh sections with Rupelian age (Daneshian & Raziei, 2004), Maragh section the Aquitanian (Raziei, 2004), Jazeh sections the Rupelian-Chattian (Mohammadi et al., 2009), Navab section the Aquitanian-Burdigalian (Daneshian & Aftabi, 2010), Kaftarkuh section the Aquitanian (Estakhr, 2010), Khafr section the Aquitanian (Daneshian & Naderi, 2013) and in northeast Delijan the  Rupelian-Chattian (Karevan et al., 2014) were considered. So, Farnagh stratigraphic section was selected for lithostratigraphic study and age determination in southeast Delijan. Although the Qom Formation deposits were attributed to Oligo-Miocene in this area, we expect the existence of deposits with Oligocene and Miocene (Aquitanian) age. But geological and paleontological studies in this research, confirm the end of Early Miocene. This situation is possibly because of tectonic and performance which caused considerable changes in lithology, facies and age with little distance.

    Material and methods

    After reconnaissance and choice appropriate section, a systematic sampling was done of the Qom Formation. Preparation of samples contains making thin sections of hard samples and washing soft samples then separation foraminifera in usual methods. Study of thin sections was carried out with optical microscope and stereomicroscope was used for soft samples. For identification of benthic and planktic foraminifera were used many references such as Henson (1950), Blow (1959), Huang (1964), Wynd (1965), Adams & Bourgeois (1967), Postuma (1971), Kennett & Sirinivasan (1983), Papp & Schmid (1984), Bolli & Saunders (1985) and Loeblich & Tappan (1988). Based on presence of different species, range chart of foraminifera was drawn and compared with biozonation of Adams & Bourgeois (1967) and Wynd (1965).

    Results and discussion

    Study of 210 collected samples including 151 hard and 59 soft led us to recognition 45 genera and 64 species, contains 38 genera and 54 species of benthic and 7 genera and 10 species of planktic foraminifera. While 27 genera and 39 species of benthic and 4 genera and 5 species of planktic foraminifera were identified of thin sections and 15 genera and 18 species of benthic and 6 genera and 7 species of planktic foraminifera from soft samples. Important index foraminiferal taxa of Farnagh section such as Ammonia beccari, Ammonia stachi, Austrotrillina asmariensis, Austrotrillina howchini, Borelis melo curdica, Bozorgniella sp., Globigerinella obesa, Globigerinoides subquadratus, Globorotalia archeomenardi, Rotalia viennoti and Valvulina sp.1, confirm the Early Miocene (Burdigalian). The Burdigalian age is corroborated specially by Borelis melo curdica in the major part of studied sequence. So from 558 m thickness, about 15 m (in bottom) are Aquitanian and 543 m belong to Burdigalian. While, the presence and stratigraphic position of species such as Ammonia beccari, Austrotrillina howchini, Globigerinella obesa, Globigerinoides subquadratus and Globorotalia archeomenardi with above species are confirmed an Early Miocene (Burdigalian) age for most part of this succession.
    According to presence of index species and similarity to Asmari Formation’s fauna, this section is comparable to Borelis melo group-Meandropsina iranica Assemblage Zone (biozone 1) and Miogypsinoides-Archaias-Valvulinid Assemblage Zone (biozone 2) of Adams & Bourgeois’ biozonation (1967) and Austrotrillina howchini - Peneroplis evolutus assemblage zone (biozone 59) and Borelis melo-curdica assemblage zone (biozone 61) of  Wynd biozonation (1965). So that samples 1 to 9 specifies biozone 2 and samples 10 to 160, biozone 1 of Adams & Bourgeois’ biozonation (1967). These results show that the outcrops of the Qom Formation in Farnagh section are different from the foraminiferal contents and age with adjacent areas and possibly is affected and performance of tectonic and caused Oligocene and main part of Aquitanian sediments not present in this section.

    Keywords: Qom Formation, Foraminifera, Biostratigraphy, Farnagh, Early Miocene
  • Javad Saadatnejad* Pages 162-171
    Introduction

    The Karaj Formation, first introduced by Lorenz (1964) and named by Glaus 1965 It consists of sedimentary, pyroclastic and extrusive igneous rocks representing five official Members of lower shale, middle tuff, Asara shale, upper tuff and Kandovan shale in ascending order. The plant macrofossils studied in this paper were collected from sediments of middle Eocene Kandovan shale (based on Tehran 1:100000 sheet) in north side of Arangeh anticline (Arangeh province) and northeast of Karaj (northwest of Tehran). There has been no systematic and detailed study of the plant macrofossils of Karaj Formation to date. The plant macrofossils have been found in the Karaj Formation are mostly fossil wood and fossilized tree branches and stems, As the most accurate report of the plant macrofossils of the Karaj Formation includes only the plant fossils debris from monocotyledones without reference to a plant member (leaves, branches, etc.) In middle tuff, Asara shale and upper tuff Members have been different sections of the Karaj Formation (Assereto, 1966; Dedual, 1967). In aforementioned view, the main purpose of this article is to introduce at least generic groups of plant macrofossils from Karaj Formation and to provide a detailed study and to provide a starting point for future studies of Tertiary plant macrofossils, especially the Karaj Formation in Iran.

    Material and Methods

    Arangeh region are located in NW of Tehran and NE of Karaj and between 51° 5'-10' E and 36° 54'-57' N. The localities studied is in northern highlands of rural district. The access path is Tehran, Karaj, road Chalus, Aderan  and Arangeh (before Karaj dam). Arangeh syncline (studied area) has been located along the NW-SE axis, northeast of Karaj city, north of thrust north of Tehran and south-southwest thrust of Imamzadeh Davood (Sheet 1:100000 Tehran) and studied area is in north edge of Arangeh syncline. The central core of the Arghana syncline is composed of sedimentary and partly pyroclastic layers of the Kandovan shale Member. The Kandovan shale Member in Arangeh syncline is divided into two parts. The lower part (Es6) of 100 m thick consists of shale, siltstone, sandstone and silty tuff which is entirely gray-brown in color and the upper part (Esc6) of the Kandovan shale in the syncline consists of layers of sandstone, shale and conglomerate with interlayers of tuff. The fossils studied in this paper are derived from sediments of the lower of Kandovan shale (Es6) in the region. The age of the Kandovan Shale Member in the Arangeh syncline (both lower and upper parts) is Middle Eocene.

    Discussion

    The founded samples of region is consist of Horsetails (Equisetum), Lycophyta (Lycopodiales), comminute leaves from Monocotyledons from Cyperaceae (Poales), juvenile branches with pinnules and male Inflorescence from Dicotyledones from Casuarinaceae (Fagales order), organogenetic of Dicotyledones (probably fruit) and Rhizomes of Monocotyledons and most samples have been identified in the family, order or higher classes due to incompleteness and lack of proper preservation.
    Sub Kingdom: Tracheophyta (Vascular Plants)
    Division: Sphenophyta (Equisetophyta) (Horsetails)
    Class: Sphenopsida (Equisetopsida)
    Order: Equisetales
    Family: Equisetaceae
    Genus: Equisetum Linne, 1770
    Division: Lycopodiophyta (Lycopodes)
    Class: Lycopodiopsida
    Order: Lycopodiales (Club mosses)
    Division: Magnoliophyta (Angiospermae) (flowering plants)
    Class: Liliopsida (Monocotyledons)
    Order: Poales
    Family: Cyperaceae (Sedges)
    Class: Magnoliopsida (Dicotyledons)
    Order: Fagales
    Family: Casuarinaceae
    Unknown Dicotyledons organogenetic
    Unknown Rhizomes
    Concolusion
    In this study plant macrofossils from Karaj Formation, plant macrofossils of two Orders Poales and Fagales from Iran and plant macrofossils of two Division of Sphenophyta (Horsetails), Lycopodiophyta from Cenozoic sediments from Iran and Casuarinaceae Family from out of Gondwana are reported for the first time.
    On the basis of material, it can be concluded that humid-temperate and environments of them are suggested lush and humid.
    Keywords:.
    References
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    Assereto, R., 1966. Geological map of Upper Djadjerud and Lar Valleys (Central Elburz, Iran), with explanatory notes. Institute of Geology of the University of Milan, 32: 1-86.
    Boureau, E., 1971. Cours de botanique, Les Sphenophyta. Biologie et Historie evolution, Paris, 1-167.
    Cleal, C.J., & Benton, M.J., 1993. The Fossil Record. Part: Plants, London, 779-808.
    Collinson, M.E., Boulter, M.C., & Holmes, P.L., 1993. Magnoliophyta (Angiosperae). In: Benton, M.J., (ed.), Chapman & Hall, London, 809-840.
    Dedual, E., 1967. Zur Geologie des mitteren und unteren Karaj-Tales, Zentral Elburz (Iran). Mitteilungen of Geological Institute at ETH University of Zurich, 76: 1-123.
    Glaus, M., 1965. Die Geologie des Gebietes nordlich des Kandevan-Passes (Zentral-Elburz), Iran. Mitteilungen of Geological Institute at ETH University of Zurich, 48: 1-165.
    Lorenz, C., 1964. Die Geologie des oberen Karaj-Tales (Zentral - Elburz) Iran. Thesis University Zurich, 1-113.
    Schaffner, J.H., 1930. Geographic distribution of the species of Equisetum in relation to their phylogeny.  American Fern Journal, 20: 89-106.
    Scagel, R.F., Bondini, R.J., Maze, J.R., Rouse, G.E., Schofield, W.B., & Stein, J.R., 1984. Plants, an Evolutionary Survey. Wadsworth Publishing Company, Belmont, CA, 1-756.
    Stewart, W.N., 1983. Paleobotany and the evolution of plants. Cambridge University, Press, 1-405.
    Stocklin, J., 1971. Stratigraphic Lexicon of Iran; Part 1, Central, North and East Iran. Iran Geological Survey, 18: 1-384.
    Wilf, P., Ruben Cuneo, N., Johanson, K.R., Wing, S., & Obradovich, J.D., 2003. High plant diversity in Eocene South America: Evidence from Patagonia. Science, 300: 122-125.
    Wilf, P., Johanson, N.R., Cuneo, N.R., Smith, N.E., Singer, B.S., & Gandolfo, M.A., 2005. Eocene Plant diversity at Laguna del Hunco and Rio Pichileufu, Patagonia, Argentina. American Naturalist, 165: 634-650.
    Wilf, P., 2008. Fossil Angiosperm leaves: pleontology’s difficult children prove themselves. Pleontological society papers, 14: 319-333.
    Wilf, P., Little, S.A., Iglesias, A., Zamaloa, M.C., Gandolfo, M.A., Cúneo, N.R., & Johnson, K.R., 2009. Papuacedrus (Cupressaceae) in Eocene Patagonia: A new fossil link to Australasian rainforests. American Journal of Botany, 96: 2031-2047.
    Zamaloa, M.C., Gandolfa, M.A., Gonzalez, C.C., Romero, E.J., Cuneo, N.R., & Wilf, P., 2006. Casuarinaceae from the Eocene of Patagonia, Argentina. International Journal of Plant Sciences, 167 (6): 1279-1289.

    Keywords: plant macrofossils, Arangeh, Karaj Formation, Middle Eocene, Central Alborz
  • Fatemeh Hadavi* Pages 172-181
    Introduction

    The Kopet-Dagh Depositional Basin has hosted a site for deposition of Jurassic to Miocene which well exposed in parts of Turkmenistan, north of Afghanistan and the northeast of Iran (Aghanabati, 2004). One of the most prominent Formations of the Upper Cretaceous in the Kopet-Dagh Basin is the Abderaz Formation. The main lithology of this formation includes shale and marls with three horizons of chalky limestone. The aim of this study is to determine ostracoda, from Abderaz Formation in Mozduran section.

    Material and methods

    A total of 102 samples of the Abderaz Formation in the east of the Kopet-Dagh Basin were collected. Samples were soaked in a mixture of water and 15% hydrogen peroxide. The content of each bucket was washed up and passed through sieves of 30 and 80-mesh.The sieves had been topped on each another regarding the grain size from course to fine. The samples were, then, dried off and transferred onto standard cans. The ostracoda, themselves, were separated from the rest of sediments through a brush and stored in some slides. Sticking the samples on the stubs, and covered by a film of gold. Then all of samples were photographed and studied.

    Results and Discussion

    Ostracoda are one of group of fossils that are index for reconstruction of environmental conditions. Due to the higher sensitivity to environmental changes, so are local. This leads to a lack of global standard biozonation for them. Not with standing this fact, the Ostracodas have saved their own biostratigraphy validity. In the studied samples, all specimens from the Abderaz Formation in Mozduran section are well preserved. In the studied section, 16 genera, and 40 species of the ostracoda were identified. The studied interval spans the 4 ostracoda biozones. In this research in addition to the investigation of ostracoda, calcareous nannofossils have been studies too, and compared. Ostracoda biozones and results of the comparison with calcareous nannofossils are as follow:1- Rehacythereis sp. Interval Zone
    This biozone is virtually equivalent to the biozone of Calculites obscurus (CC17) and Aspidolitus parcus parcus (CC18) of Sissingh (1977).
    2- Haplocytheridea sp. Interval Zone
    This biozone is virtually equivalent to the biozone of Calculithes ovalis (CC19) of Sissingh (1977).
    3- Veenia sp. Interval Zone
    This biozone is virtually equivalent to the biozone of Ceratolithoides aculeus (CC20) of Sissingh (1977).
    4- Cytherellaida sp. 5 Range Zone
    This biozone is virtually equivalent to the biozone of Uniplanarius sissinghii (CC21) of Sissingh (1977).
    Based on the identified calcareous nannofossils and ostracoda, the age of the Abderaz Formation in Mozduran section is Late Santonian to Early late Campanian.

    Keywords: Ostracoda, Abderaz, Kopet-Dagh, Mozduran
  • Hosein Gholamalian* Pages 182-197
    Introduction

    Kazhdumi Formation has been noticed as a hydrocarbon mother rock. On the other hand, it contains very diverse fauna such as corals, bivalves, gastropods, ammonites and echinoids, but there are a few investigations on these groups. Some researchers as Bulot (2010), Kennedy et al. (2009); Asadi et al. (2015) studied ammonites of Kazhdumi Formation. Dehghani et al. (2012) introduced some bivalves and echinoids from northern Shiraz. Kamyabi-Shadan et al. (2014) implicated the stratigraphic position of genus Macraster.

    Materials and methods

    Studied section is located in the eastern flank of Kuh-e-Gurgen, 21 km NW Noor-Abad, West of Fars Province. Kazhdumi Formation with 194.7 m of shale and a few limestone beds is studied here. A rich echinoid fauna (126 speciements) of regular and irregular echinoids is collected from 11 beds (N1 to N9 and N9a to N10) of the Kuh-e-Gurgen section. Echinoid species are identified based on their general characteristics and diameter ratios as well as fine structures and sculptures. Eighteen thin sections have been provided for age determination.  

    Discussion

    Eight species belonging to five genera are identified as: Anorthopygus orbicularis, Cidaris (Dorocidaris) taouzensis, Coenholectypus planatus, Macraster douvillei, Macraster longesulcatus, Macraster obtritus, Pedinopsis aff. sinaica and Toxaster granosus. One species, Dorocidaris taouzensis has been reported from Iran for the first time. Presence of the mentioned species shows the age of Cenomanian for the top of Kazhdumi Formation in the Kuh-e-Gurgen section.

    Keywords: Echinoidea, Kazhdumi Formation, Cretaceous, Albian, Cenomanin, Noor-Abad, Kuh-e-Gurgen
  • Ebrahim Mohammadi* Pages 198-219
    Introduction

    The marine Qom Formation was deposited at the north-eastern coast of the Tethyan Seaway (Reuter et al., 2009). Its deposition took place in three NW-SE-trending basins: Sanandaj-Sirjan fore-arc basin, Urumieh-Dokhtar magmatic arc (Intra-arc basin) and Central Iran back-arc basin (Mohammadi et al., 2013, 2015). Transgression of the Qom Sea started from the southeast and continued northwestward gradually. Evaporate deposits of the Qom Formation were deposited merely in a rather small area of the Central Iran back-arc basin and deposited in the Early Miocene (Aquitanian-Burdigalian). Because of high facies changes of the Qom Formation and its situation in intermountain basins, defining a depositional model for the Qom Formation for the whole of the Central Iran is impossible. The aim of this research is to study of the biostratigraphy, microfacies and depositional model of the Qom Formation in Natanz area.

    Material and Methods

    One stratigraphic section of the Qom Formation was measured and sampled in Natanz area with the aim to study its biostratigraphy, microfacies and depositional model. A total of 166 samples were collected systematically and based on facies and texture changes. All samples were studied in detail by microscope. Based on different studies the obtained foraminifera were identified and age of the study section was determinate. The classification of carbonate rocks followed the scheme of Dunham (1962) and Embry & Klovan (1971). Finally, depositional model of the study section was reconstructed. 

    Discussion

    The study succession with 330 m thickness is one of the most cliff-forming outcrops of the Qom Formation and lithologicaly are composed of two parts: the lower part with 210 m thickness consists mainly of medium to thick bedded and massive limestone, reefal limestone and shale; while, the upper part with 120 m thickness is composed of medium to thick bedded limestone and marl. On the basis of recognized foraminifera and their vertical distribution, the Qom Formation is Rupelian?-Chattian-Aquitanian in age in the study area. Field and laboratory studies caused to identification of 9 microfacies, they are: A) Shale; B) Bioclastic imperforate foraminifera packstone; C) Sandy bioclastic miliolida wackestone; D) Coral boundstone; E) Bioclastic perforate and imperforate foraminifera packstone; F) Marl; G) Bioclastic perforate foraminifera packstone; H) Bioclast wackestone; I) Bioclastic bryozoan packstone. The investigation results indicate that the lower part of the study section deposited mainly in lagoonal settings; while its upper part deposited entirely in the open marine setting. At the end of the deposition of the lower part, increasing of the colloidal grain inputs (which characterized by the abundance presence of the marly facies) and depth (which characterized by the presence of typical fauna of the deeper settings) prevented the growth of the reef-forming corals. According to recognized microfacies and field investigations, deposition of the Qom Formation in northeastern Natanz took place on a carbonate ramp. The proposed carbonate ramp can be divided into inner ramp and middle ramp. Inner ramp is characterized by high abundance of imperforated foraminifera and mainly includes the lower part of the study section. Inner ramp is dominated mainly by A to E microfacies. Middle ramp is characterized by high abundance of larger benthic foraminifera with hyaline wall and mainly includes the upper part of the study section. Middle ramp is dominated mainly by F to I microfacies. Deposits of the outer ramp, which is characterized by absence of larger benthic foraminifera together with the presence of planktonic foraminifera and light-independent organisms, are not recognized in the study section.

    Keywords: Qom Formation, Oligo-Miocene, Coral reef, Ramp, Qom back-arc basin
  • Fatemeh Vaez* Pages 220-243
    Introduction

    Hojedk Formation is well-exposed at the Kouchekali area, south western of the Tabas city. It consists of mainly grey-dark shale, siltstone and sandstone intercalating with coal seams. Here, the core number 169 was studied and plant macrofossils were collected. Thirty-two species of plant macrofossil remains allocated to nineteen genera of various orders such as Equisetales, Dicksoniales, Schizaeales, Caytoniales, Bennettitales, Cycadales, Ginkgoales and Pinales were identified. On the basis of the occurrence of index fossils such as Coniopteris hymenophylloides, Elatides thomasii, Klukia exilis and Nilssonia macrophylla, Aalenian-Bajocian age is suggested for this assemblage. One assemblage zone (Klukia exilis-Nilssonia macrophylla) and four sub-biozones were recognized in this formation. These subzones are: I) Sagenopteris nilssoniana-Equisetites columnaris Concurrent range zone, II) Equisetites beanii-Ptilophyllum harrisianum Concurrent range zone, III) Ginkgoites huttonii Taxon range zone and IV- Ferizianopteris undulata-Coniopteris hymenophylloides Assemblage zone. Biozones of the Hojedk Formation in the Kouchekali area were correlated to the similar age sediments of the Mazino area (Tabas Block), the Dansirit Formation in Baladeh and Rudbarak areas (Central Alborz Mountains) and Bazehowz Formation in its type section (south Mashhad, Binalud Mountains). Moreover, on the basis of relative abundance of Filicales and Cycadales in this area, a humid sub-tropical (warm temperate) climate or is suggested for this period of time.
    Material, methods and geological setting
    The plant fossils have been driven from the borehole number 169, North Kouchekali, W Tabas city, 33˚17´North, 56˚18´East. A total of 86 specimens have been collected from a 405 m stratigraphic-core section. Some specimens yielded more than one fossil. There were several coal seams among this core. The flora from this locality is here introduced for the first time. Material cited in this work (prefixed FJNK; acronym for Fatemeh, Javadi, Namjoo and Kouchekali) is held in the collection of the Palaeobotany Laboratory of the Faculty of Geology at University of Tehran.
    Systematic palaeobotany
    North Kouchekali core section, W Tabas city contains well-preserved plant macrofossils belonging to 32 species allocated to 19 genera. These fossils are: Anomozamites sp., Cladophlebis aktashensis, Cladophlebis whitbyensis, Coniopteris hymenophylloides, Ctenis sp. cf., Ctenis sulcicaulis, Dictyophyllum sp., Elatides thomasii, Elatocladus zamioides, Equisetites beanie, Equisetites columnaris, Ginkgoites huttonii, Klukia crenata, Klukia exilis, Lobifolia rotundifolia, Lobifolia sp., Neocalamites sp., Nilssonia feriziensis, Nilssonia macrophylla, Nilssonia orientalis, Nilssonia sp., Nilssonia sp. cf., Nilssonia tazarensis, Nilssonia tenuicaulis, Nilssonia undulate, Podozamites distans, Pterophyllum feriziense, Ptilophyllum harrisianum, Rhizomopteris rezaii, Sagenopteris nilssoniana and Sphenobaiera sp.
    Biostratigraphy of the North Kouchekali
    The Hojedk Formation consists of shale, siltstone and fine-sandy silt alternating with a thick medium-grained sandstone at the base of column. Several coal seams present at the middle and upper part of the core column. One assemblage biozone was established in this section with lower and upper boundaries identified by FOO (First Observed Occurrence) and LOO (Last Observed Occurrence) of Klukia exilis and Nilsssonia macrophylla respectively. Furthermore, four informal subzones were recognized which are upward: I) Sagenopteris nilssoniana-Equisetites columnaris Concurrent range zone; II) Equisetites beanii-Ptilophyllum harrisianum Concurrent range zone; III) Ginkgoites huttonii Taxon zone and IV) Coniopteris hymenophylloides-Nilssonia feriziensis Concurrent range zone.
    Geographic and stratigraphic distribution of taxa
    Floristic association described here is widespread in the Central-East Alborz Mountains, Kerman Basin and Tabas area in the early Middle Jurassic. Similar plant macrofossil assemblages have been distinguished from the Shemshak Group in the Alborz Mountains, the Bazehowz Formation in the Binalud Mountains and the Hojedk Formation in the Kerman Basin and in the Tabas area (e.g. Barnard & Miller, 1976; Fakhr, 1977; Schweitzer et al., 2000, 2003; Vaez-Javadi, 2011, 2012, 2014; Vaez-Javadi & Allameh, 2015).
    Relative abundance of Taxa in North Kouchekali
    Relative abundances of morphocats was studied in which the relative abundances of Filicales and Equisetales and macrophyllous cycadophytes were 38.5% and 37% respectively. It is noteworthy that variety of the species of Genus Nilssonia (six species) and species of Order Ginkgoales (two taxa), as a macrophyllous cycadophyte was high within the North Kouchekali core column. Therefore, a humid subtropical (warm temperate) climate is considered during this period of time in this area.
    Floral gradient analysis of the flora of North Kouchekali
    In order to recognized palaeoclimate of the Calshaneh area during the Middle Jurassic floral gradient and correspondence analysis was used. Ziegler et al. (1996) assigned all Jurassic leaf genera to ten coarser morphological categories (or 'morphocats'). These are sphenophytes, ferns, pteridosperms, microphyllous cycadophytes, unassigned (intermediate or morphologically variable) cycadophytes, macrophyllous cycadophytes, ginkgophytes, microphyllous conifers, unassigned (intermediate or morphologically variable) conifers and macrophyllous conifers. These groups parallel the major taxonomic subdivisions which in turn reflect the individual physiognomic strategies of their constituent plants. Rees et al. (2000) explained "Floral gradient" analysis. They show how this analysis can be used to interpret phytogeographic patterns based on the axis 1 scores of individual leaf genera and corresponding plant localities, due to their relative degrees of association. Then it can be understood these climatically in terms of the basic morphological characteristics of individual leaf genera and the palaeogeographic distribution of plant localities. By averaging the scaled (0 to 100) axis 1 scores of the 32 genera common to all three intervals, a Jurassic 'floral gradient' has been derived. In this case, microphyllous conifers and microphyllous cycadophytes have low scores, whereas macrophyllous conifers and ginkgophytes have high ones. Ferns and macrophyllous cycadophytes occupy the central portion of the gradient, along with sphenophyte genera such as Equisetites. Using the floral gradient, can assign a value to any Jurassic plant locality simply by averaging the scores of its constituent leaf genera. In this study I established this analysis. Floral gradient score of the North Kouchekali flora is 56.2. This shows that the flora assigned to the middle part of Table and suggests a humid and sub-tropical climate during early Middle Jurassic.

    Conclusion

    In this study, new data have been provided from the Hojedk Formation at the North Kouchekali, west of Tabas city, central-east Iran. Jurassic deposits in this core-column contains thirty-two species of plant macrofossil remains belonging to nineteen genera of various orders such as Equisetales, Dicksoniales, Schizaeales, Caytoniales, Bennettitales, Cycadales, Ginkgoales and Pinales. On the basis of the occurrence of index fossils such as Coniopteris hymenophylloides, Klukia exilis, Nilssonia macrophylla and Elatides thomasii, Aalenian-Bajocian age is suggested for this assemblage. One assemblage zone (Klukia exilis-Nilssonia macrophylla) and four informal sub-biozones were recognized in this formation. These subzones are upward: I) Sagenopteris nilssoniana-Equisetites columnaris Concurrent range zone, II) Equisetites beanii-Ptilophyllum harrisianum Concurrent range zone, III) Ginkgoites huttonii Taxon range zone and IV) Ferizianopteris undulata-Coniopteris hymenophylloides Assemblage zone.  This assemblage biozone is comparable to other biozones of the same age in Iran. Furthermore, relative abundances of taxa and morphocats were studied and relative abundances of Filicales, Equisetales, macrophyllous and cycadophytes were 38.5% and 37% respectively. It is noteworthy that variety of the species of Genus Nilssonia (six species) and species of Order Ginkgoales (two taxa), as a macrophyllous cycadophyte was high within the North Kouchekali core column. In addition, floral gradient score of this assemblage is 56.2. This shows that the flora assigned to a humid and sub-tropical climate (warm temperate biome) during the Middle Jurassic.

    Keywords: Plant macrofossil, Hojedk Formation, Biostratigraphy, N. Kouchekali, Tabas, Climate
  • Mahdi Hadavi* Pages 244-256
    Introduction

    Large benthic foraminifera (LBF) is an informal group of benthic foraminifers that characterized by complicated internal structures and relative large sizes with bathymetric distribution under environmental factors. The main objective of this study is palaeoecological reconstruction of the Eocene shallow- marine carbonate successions based on morphological characters and hydrodynamic behavior of LBF from the Soltanieh Mountains (western Alborz).     

    Material and methods

    This study has been done on three sedimentary successions from Gheynarjeh and Ghaziabad locations. Gheynarjeh 1, 2 are located at 19 km southeast of the city of Zanjan (close to Gheynarjeh Village) with thickness of 52 m and 34 m respectively. The Ghaziabad section is 25-m thick and located near the Ghaziabad Village (about 25 km south of the city of Zanjan) and about 5 km southwest of the Gheynarjeh 2 section. In total, 50 samples were collected from these sections. After preparation, they were examined in terms of microfossils contents especially LBF. Some samples contained a fair number of well-orientated large benthic foraminifera. We have used relative differences in D/T measurements of LBF and the ratio of the megalospheric (A-form) tests to the microspheric (B-form) tests in palaeoenvironmental interpretation.
    Results and

    conclusion

    The distributional pattern of LBF and their ecological gradient are represented by four assemblages: 1) Alveolinids assemblages: this assemblage has a high diversity of alveolinids Alveolina ellipsoidalis (Schwager), Alveolina tumida (Hottinger), Alveolina laxa (Hottinger), Alveolina pisiformis (Hottinger), Alveolina rotundata (Hottinger), Alveolina subpyrenaica (Leymerie) associated with smaller porcelaneous foraminifera (mainly miliolids), rare Orbitolites sp. and nummulitids which are represent at maximum depth 40 m under the influence of high energy conditions by wave action in a lagoonal environment. In generally, They were observed down to depths of 80 m (Hottinger 1983, 1997); 2) Nummulitids assemblages: this assemblages is dominated by robust and ovate Nummulites tests on palaeohigh, relatively minor with low relief submerged near fair- weather wave base, with a ratio of A to B forms of 50:1 to 75:1 that affected by wave and current (storm?) action at depth less than 80 m; 3) Encrusting Foraminifera assemblages: The highly abundances of encrusting foraminifera (acevulinids) in this assemblage had constructed the “reefs” at moderate depths in the euphotic zone (40-80 m). In fact, the presence of encrusting foraminifera such as physical barrier may play a major role in decreasing of hydrodynamic energy and 4) Orthophragminids assemblages: this assemblage is dominated by flattened and saddle-like formrs of orthophragminids Discocyclina javana (Verbeek), Discocyclina sp., Discocyclina dispansa sp. cf., Discocyclina dispansa (Sowerby), Orbitoclypeus sp. cf. and Orbitoclypeus marthae associated with nummulitids at a depth range between 80 to 100 m (outer ramp setting).

    Keywords: Western Alborz, Eocene, Large benthic foraminifera, Bathymetric, Soltanieh Mountains