دانشگاه اصفهان پژوهش های چینه نگاری و رسوب شناسی 2008-7888 36 1 2020 03 20 Investigating the effect of various stratigraphy on karst development and variability of karst springs discharges, Kermanshah Province بررسی تأثیر واحدهای سنگ‌چینه‌شناسی مختلف بر توسعۀ کارست و تغییرپذیری آبدهی چشمه‌های کارستی، استان کرمانشاه 1 20 24410 10.22108/jssr.2019.118118.1110 FA زینب نجفی دانشکده علوم زمین، گروه آبشناسی، دانشگاه صنعتی شاهرود، شاهرود، ایران غلامحسین کرمی دانشیار، گروه آبشناسی، دانشکده علوم زمین، دانشگاه صنعتی شاهرود، شاهرود، ایران حاجی کریمی استاد گروه مرتع و آبخیزداری، دانشکده کشاورزی، دانشگاه ایلام، ایلام، ایران Journal Article 2019 07 15 Abstract In karstification phenomenon of carbonate formations various factors are involved which the most important of them are lithology, precipitation, stratigraphic characteristics, structural factors and the topography of the region. Thick and massive limestones have much higher potential for the development of karst and, as a result, the formation of karst features. In this research, four important karstic springs have been investigated, the name of these springs are Ravansar, Kabotarlaneh, Sahneh and Kashanbeh. The catchment areas of these springs are located in the different geological formations with various lithologies and ages. The discharge of springs and its variability depends significantly on the lithology of the aforementioned formations. The average annual discharge of the Ravansar, Darband Sahneh, Kashanbeh, and Kabotarlaneh springs in the hydrological year 2016–2017 is 1932, 462, 166 and 771 lit/s, respectively. Moreover, the coefficients of variation of these karst springs are 1.07, 0.30, 0.49 and 0.48 and the maximum to minimum ratio of these springs were calculated 20, 2, 7 and 4, respectively. The Ravansar and Kabotarlaneh springs have three discharge coefficients, while the springs of the Sahneh and Kashanbeh have two, which are related to stratigraphy and lithology of their basins. The largest of the aquifer storage from these springs is dedicated to the Ravansar spring, and the smallest is Kashanbeh; the discharge of these springs also confirms it. Keyword: Stratigraphy, Karst Development, Karst spring, Kermanshah Introduction: ‘‘Karst’’ refers to terrain with distinctive landforms and a largely subsurface drainage system, arising from the high solubility of certain rocks in natural waters (Karami 2002). Although karstic areas mainly develop on carbonate rocks (limestone in particular), they are not limited to these rocks and can also develop on other soluble rocks (e.g. gypsum, anhydrite, and halite). Several factors are involved in karst development, the karst development is mainly controlled by lithology, precipitation, stratigraphic, characteristics of structural factors and the topography of the area. Among them, the lithology and stratigraphic characteristics of carbonaceous formations are of particular importance. Thick and massive carbonate rocks have a higher degree of karst development and, as a result, more obvious karstic features. There are many karst springs (that is called “Sarab” in the local lingo) in Kermanshah province (more than 200 springs). The mean annual discharge of these springs is relatively considerable (the average annual discharge some of them is up to 3000 lit/s). In this study, karstic springs have been selected from different regions of the province and their characteristics related to the stratigraphy of spring's basin have been studied. The purpose of this study is to investigate the stratigraphic role of different formations on discharge fluctuations of the selected springs in the study area. Material & Methods: For achieving the aim of this research as the initial evaluation, geological maps in the area were concerned and then springs were selected whose catchment area are located in different carbonate formations or have different lithologies status. In the fieldwork electrical conductivity and water temperature of springs has been measured. Spring's water was sampled monthly during a water year (2016–2017) and concentration of major ions of samples was determined in the hydrology laboratory of the Shahrood University of Technology by titration method, then the results were randomly re-measured at the Freie Universität Berlin (FUB) by ion chromatography, which showed high precision results. After following the steps mentioned above estimating recharge potential zone in the study area was estimated and the catchment area of the springs was determined. Finally, the effect of various stratigraphy on karst development and variability of karst springs discharges and groundwater flow in karst aquifers was investigated. Discussion of Results & Conclusions The role of stratigraphy in karst aquifers is very important and plays a major role in karst development and the creation of various conduits and dissolution spaces in the aquifer of springs. This theme is well visible in the evaluation of the four springs of Ravansar, Kabotarlaneh, Darband, and Kashanbeh. Ravansar spring's basin due to the Bistoon Formation has high karst development and consequently high fluctuations in discharge, electrical conductivity, and temperature. Many studies have been carried out to determine the flow type and thickness dynamics of a karstic aquifer, mainly evaluating the physical and chemical properties of springs. Changes in the physical and chemical properties of the water of the selected springs are different and are influenced by the stratigraphy and geological characteristics of the catchment basins of these springs. The discharge coefficients and variations of the measured parameters for Ravansar spring indicate that conduit flow system is dominant in karst aquifer feeding this spring. According to the characteristics of the Kabotarleneh spring, the conduit system in its aquifer has become less developed in comparison to the Ravansar spring which is related to its different stratigraphy. The characteristics of catchment areas of the Darband are similar to the Kabotarlaneh spring, which has caused the flow system of the Darband spring to be similar to the Kabotarleneh spring. According to characteristics of Kashanbeh Springs, it has a diffuse-conduit flow system. عوامل مختلفی در پدیدۀ کارستی‌شدن سازندهای کربناته نقش دارند که از مهم‌ترین آنها عبارتند از: سنگ‌شناسی، مقدار بارش، ویژگی‌های چینه‌شناسی، عوامل ساختاری و توپوگرافی منطقه و در این میان، ویژگی‌های سنگ‌شناسی و چینه‌شناسی اهمیت ویژه‌ای دارند. در پژوهش حاضر، چهار چشمۀ کارستی مهم با چینه‌شناسی مختلف شامل چشمه‌های روانسر، کبوترلانه، دربند صحنه و کاشنبه بررسی شدند. آبخوان تغذیه‌کنندۀ این چشمه‌ها به‌ترتیب از آهک‌های توده‌ای و ضخیم‌لایۀ سازند بیستون، آهک‌های کرتاسۀ اربیتولین‌دار و توده‌ای، آهک کرتاسه و آهک مارنی و آهک تله‌زنگ و واحدهای سنگی آواری سازند امیران تشکیل شده‌ است. آبدهی این چشمه‌ها و تغییرپذیری آن به‌طور درخور توجهی به سنگ‌شناسی سازند‌های یادشده وابسته است؛ به‌این‌تریتب که میانگین آبدهی سالانۀ چشمه‌های روانسر، دربند صحنه، کاشنبه و کبوترلانه در سال بررسی‌شده به‌ترتیب 1932، 462، 166و 771 لیتر بر ثانیه است؛ همچنین ضریب تغییرات آبدهی چشمه‌های یادشده به‌ترتیب 07/1، 30/0، 49/0و48/0 و نسبت حداکثر به حداقل میزان آبدهی این چشمه‌ها به‌ترتیب 20، 2، 7 و 4 محاسبه شده است. چشمه‌های روانسر و کبوترلانه سه ضریب و چشمه‌های دربند صحنه و کاشنبه هرکدام دو ضریب کاهش دبی دارند که به حوضۀ آبگیر و سنگ‌شناسی آن در این چشمه‌ها مربوط است. بیشترین حجم ذخیرۀ آبخوان‌ها به چشمۀ روانسر و کمترین به چشمۀ کاشنبه اختصاص دارد؛ آبدهی این چشمه‌ها مؤید این مطلب است.

https://jssr.ui.ac.ir/article_24410_c6a556f07650328d34def255ca57b69e.pdf

دانشگاه اصفهان پژوهش های چینه نگاری و رسوب شناسی 2008-7888 36 1 2020 03 20 Assessing the heavy metal contamination in sediments of Mighan playa using pollution indices ارزیابی آلودگی فلزات سنگین در رسوبات تالاب میقان با استفاده از شاخص‌های آلایندگی 21 38 24322 10.22108/jssr.2019.119776.1124 FA فریدون قدیمی گروه مهندسی معدن، دانشکده مهندسی علوم زمین، دانشگاه صنعتی اراک، استان مرکزی، ایران Journal Article 2019 10 26 Abstract Mighan playa in the central part of Arak watershed receives heavy elements from urban, industrial and agricultural activities. In order to evaluate the pollutants of Mighan playa, 29 sediment and soil samples were collected from playa and heavy metal concentrations were determined and compared with local and upper crust reference. The concentration of heavy metals in most samples is lower than their concentration in the crust reference. Individual contamination index, such as contamination factor, determined the degree of contamination in all samples medium for Cu and Cr and low grade for other elements. However, indices such as ecological risk, enrichment factor, and geo-accumulation index were low for all samples. Moreover, integrated indices such as sum of degree of pollution, ecological risk potential and Nemerow index for sum of elements indicate low degree of contamination. Municipal wastewater, industrial and agricultural wastewater are the most important source of heavy metals in the Mighan playa. Therefore, efforts should be taken to reduce heavy elements from pollutants, especially municipal sewage in the vicinity of the Mighan playa. Keywords: Heavy Metals, Sediment Pollution, Pollution Indices, Mighan Playa, Arak Introduction The role of human activities in the production of heavy metals can be traced to industrial activities, agricultural effluents, mining activities, urban and rural wastewater, industrial and domestic solid waste. Long-term use of heavy metals (such as Hg, Cd, As, and Pb) in an ecosystem will increase the heavy metals in organisms and cause morbidity and mortality. Arak Plain in the center of the Mighan playa is at the center of major urban, agricultural and industrial activities. Industrial, agricultural, municipal wastewaters and leachate, landfill and atmospheric depletion in Arak were the most important heavy metal production potentials that may reach the Mighan playa. In this study, the role of heavy metals will be determined by examining the concentration of heavy metals in soil and sediments in and around Mighan playa with local and international reference. On the other hand, pollution were evaluated using different indices of pollution and the degree of contamination and the source of heavy metals were determined. Material & Methods Arak basin with an area of 5500 km2 was a closed area of which 62% of its mountains, 36% of plain and 2% of Mighan playa. The playa in the center of the basin consists of two parts of island and lake. Twenty-nine samples were collected from soil and sediment from different land uses at a depth of 10 cm and measured heavy metals such as As, Cr, Cu, Ni, Pb, Zn and Cd using ICP-MS at Zarazma Lab. in Tehran. Discussion of Results & Conclusion Investigation of 29 soil and sediment samples from Mighan playa showed that the mean concentrations of As, Cr, Cu, Ni, Pb, Zn and Cd were 4.03, 53, 23, 34, 13, 50 and 0.21 mg / kg, respectively. The heavy metal values were compared with the local (As=5.90, Cr=73, Cu=23, Ni=45, Pb=13, Zn=66, Cd=0.25 mg/kg) and upper crust reference values (As=4.80, Cr=92, Cu=28, Ni=47, Pb=17, Zn=67, Cd=0.09 mg / kg). The study showed that 17.5% of the samples have arsenic above local reference and 35% above upper crust reference. 28% of Cr is above the local reference and 3.5% above the upper crust reference. The values for Cu are 43% and 21%, for Ni, 24% and 17%, for Pb, 59% and 14%, for Zn, 24% and 24%, and for Cd, 62% and 72%, respectively. Therefore, the role of human activities is significant in increasing metals in the sediments of Mighan playa. Cd and Pb are two heavy metals that accounted for the largest proportion of human influences in the Mighan playa. Most of the soils around Mighan playa are rich in elements such as As, Cr, Cu, Ni, Pb, Zn and Cd. Arak's municipal wastewater treatment is also rich in Pb and Zn. In all samples, the total contamination index is less than seven and falls within the low contamination level. In other words, soils and sediment of different land uses are not contaminated with heavy metals such as As, Cr, Cu, Ni, Pb, Zn and Cd. Ecological risk potential index was also low in all samples with less than 150. The Nemerow index fall within the safety domain in all samples (except for rangelands). The Nemerow index is within the precaution domain in the rangelands. Contamination indices in soil and sediment samples of different land use indicate no contamination of As, Cr, Ni and Zn (low pollution grade). Cu and especially Pb vary from low to medium pollution degree in most samples. Therefore, comparing the concentrations of heavy metals with local reference and upper crustal reference showed that the Mighan playa was affected by pollutants such as municipal wastewater, industrial effluent and agricultural activities. The contamination indices indicate heavy metal have low contamination and safety domain in soil and sediments of Mighan playa. If it is not controlled heavy metal pollution in wastewaters, the degree of contamination tend to intermediate to advanced degree in future. Therefore, birds and aquatic animals will be exposed to heavy metals. Since the most important source of heavy metals is urban wastewater, therefore, measures should be taken to reduce heavy metals from municipal wastewater. تالاب میقان در بخش مرکزی حوزۀ آبخیز اراک، عناصر سنگین ناشی از فعالیت‌های شهری، صنعتی و کشاورزی را دریافت می‌کند. در راستای ارزیابی آلاینده‌های تالاب میقان، 29 نمونه رسوب و خاک از تالاب برداشت، غلظت عناصر سنگین تعیین و با مرجع محلی و مرجع پوستۀ بالایی مقایسه شد. میانگین غلظت آرسنیک 03/4، سرب 13، روی 50، کروم 53، مس 33 ، نیکل34 و کادمیوم 21/0 میلی‌گرم‌در کیلوگرم و در بیشتر نمونه‌ها کمتر از مرجع بود. ضریب آلودگی و درجۀ آلودگی در تمام نمونه‌ها برای مس و کروم متوسط و برای سایر عناصر کم بود؛ همچنین شاخص‌هایی مانند ضریب ریسک اکولوژیک، ضریب غنی‌شدگی و ضریب زمین‌انباشت برای تمام نمونه‌ها درجۀ کم را نشان دادند. شاخص‌های مرکب نظیر مجموع درجۀ آلودگی، پتانسیل ریسک اکولوژیک و شاخص نمرو برای مجموع عناصر گویای درجۀ کم آلودگی بود. فاضلاب شهری، پساب صنایع و کشاورزی مهم‌ترین منشأ ورود فلزات سنگین به تالاب میقان محسوب می‌شوند؛ بنابراین، بایستی اقدامات لازم برای کاهش عناصر سنگین در منابع آلاینده به‌ویژه فاضلاب شهری در هم‌جوار با تالاب میقان انجام شوند.

https://jssr.ui.ac.ir/article_24322_c9d31786fd53f6e69b2d2955f1b611c7.pdf

دانشگاه اصفهان پژوهش های چینه نگاری و رسوب شناسی 2008-7888 36 1 2020 03 20 Palynofacies and Sporomorph EcoGroups-based paleoecology implications for the Dalichai Formation, Andariyeh, central Alborz استفاده از اکوگروه‌های اسپورومورفی (SEGs) و پالینوفاسیس برای بازسازی پالئواکولوژی سازند دلیچای، برش چینه‌شناسی اندریه، البرز مرکزی 39 60 24387 10.22108/jssr.2020.118759.1116 FA فیروزه هاشمی یزدی دکتری چینه شناسی و فسیل شناسی، مؤسسۀ تحقیقات جنگل‌ها و مراتع کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران ندا بشیری دانشجوی کارشناسی ارشد، دانشکدۀ زمین‌شناسی، پردیس علوم، دانشگاه تهران، ایران فرشته سجادی دانشیار دانشکدۀ زمین‌شناسی، پردیس علوم دانشگاه تهران، ایران Journal Article 2019 08 25 Abstract The Dalichai Formation at the Andariyeh stratigraphic section in the northeast of Andariyeh village, central Alborz Mountains, was studied by using analyses of the Sporomorph EcoGroups (SEGs) data and associated plant communities and palynofacies in order to determine its paleoecology conditions. The Sporomorph EcoGroups data from the Dalichai Formation's palynological assemblages, declination of miospores representing Upland/Lowland plant communities and proliferation of those characterizing Lowland/Coastal-Tidal plant associations interpreted to signify relatively low sea level and deposition in a marginal marine setting. Furthermore, the ratios of wetter/drier and warmer/cooler elements suggest deposition of the host strata under a moist, ±warm climate prevailing during the Middle Jurassic in central Alborz Mountains. The results of drawing diagrams of the palynofacies in the Andariyeh stratigraphic section, indicates that the Dalichai sediments accumulated in a dysoxic shallow marine environment with low sedimentation rate that corresponds well with its SEGs graphs. Keywords: Palaeoecology, Dalichai Formation, Sporomorph EcoGroups (SEGs), palynofacies, Andariyeh village, central Alborz Mountains. Introduction The Dalichai Formation is represented by greenish-grey color shales, calcareous shales, marls, and richly ammonitiferous limestones (Steiger 1966), being widely distributed in the Alborz Mountain, northern Iran. It disconformably overlies the dark, siliciclastic coal bearing Shemshak Formation and underlies gradually by the light colored, more uniform Lar Limestone containing chert concretions. The Dalichai Formation is represented the first rock unit of the Jurassic marine sediments of the Alborz Mountain. This formation includes a diverse fauna as ammonites, belemnites, bivalves, brachiopods, echinoderms, sponges, bryozoans and foraminifera (Stöcklin 1972; Sussli 1976; Nabavi & Seyed-Emami 1977; Alavi-Naini et al. 1982; Schairer et al. 1991; Shahrabi 1994; Seyed-Emami et al. 1985, 1989, 1995, 1996; Makvandi 2000; Tutunchi 2001; Shafeizad et al. 2002; Shafeizad & Seyed- Emami 2005; Alvani 2006; Niknahad 2007; Shams 2007; Vaziri et al. 2008, 2011). Due to presence of shale and marl layers, this formation has been the subject of many palynological studies.(e.g. Wheeler & Sarjeant 1990; Ghasemi-Nejad & Khaki 2002; Farisi Kermani 2003; Ghasemi-Nejad et al. 2008; Sajjadi et al. 2009; Sabbaghiyan 2009; Orak 2010; Boroumand et al. 2011, 2013; Ghasemi-Nejad et al. 2012; Dehbozorgi 2013; Dehbozorgi et al. 2013; Mafi et al. 2013; Navidi 2013; Saadati Jafarabadi et al. 2013; Hashemi-Yazdi et al. 2015; Skupien et al. 2015; Hashemi-Yazdi 2008, 2015). The purpose of this study was to determine the palaeoenvironmental interpretation of the Dalichai Formation based on SEGs data, and quantitative analysis of the palynofacies in the Dalichai Formation at the Andariyeh stratigraphic section, central Alborz. Material & Methods Totally 29 palynologically samples collected from the Dalichai Formation at the Andariyeh stratigraphic section, northeast of Andariyeh village, central Alborz Mountains. All samples were prepared following standard palynological processing procedures (Phipps & Playford 1984), including HCl (10–50%) and HF (40%) utilized for dissolution of carbonates and silicates, respectively. Then the residues were saturated with ZnCl2 solution (specific gravity 1.9 g/ml) for density separation. All the residues were sieved with a 20 μm mesh sieve prior to making strew slides. Three slides of each preparation examined by transmitted light microscope. The slides are stored in the collection of Faculty of Geology, Tehran University, Iran. For quantitative study of the prepared slides, 15 field views were randomly selected from each slide and studied with a 16 x microscope magnification lens. The particles were counted for each sample to determine palynodebries and palynofacies. An examination of facies including identification of palynomorphs, plant remains and amorphous particles, ratios of different particles and their size range in determination the paleoenvironment is very much important. Three main parameters including percentage of palynomorphs, phytoclasts, and organic matter (AOM) transferred to Tyson triple diagram (Tyson 1993) for plotting and interpretations. In addition, The Sporomorph Ecogroup Model (SEG model) of Abbink et al. (2001, 2004a) was applied to the Dalichai Formation. In this model, the miospores are classified as SEGs each, with reference to their parent plants, indicating particular palaeoecological specifications. Discussion of Results & Conclusions Palynofacies data and SEGs used to draw palaeoecological and palaeoenvironmental inferences for the Dalichai Formation at the Andariyeh stratigraphic section in central Alborz Mountains. Diverse and well preserved palynofloras embracing miospores, dinoflagellate cysts, tasmanites, scolecodont, acritarchs, and foraminiferal test linings are retrieved from the host strata. Miospores typifying all the six plant communities are retrieved from the material examined. The least and most abundant miospores taxa are those related to Pioneer and Lowland SEGs., respectively, The wet/dry curve (ratio of wetter vs drier elements) reflects variations in humidity and precipitation while the warm/cool curve (ratio of warmer against cooler elements) indicates temperature fluctuations. Quantitative analysis of the SEGs tends to suggest that the host strata accumulated under a moist, warm climate during the Middle Jurassic. Also based on palynofacies studies, a palynofacies of Tyson (1993) (II) was determined that proposed domination of a dysoxic shallow marine environment throughout the deposition of Dalichai Formation. Palynological evidence such as high proportion of the equidimensional opaque palynomaceral to the blade-shape opaque palynomaceral; the high ratio of phytoclasts to marine palynomorphs, and the abundance of transparent amorphous organic matter in comparison to the opaque amorphous organic matter, all indicates that the Dalichai sediments, accumulated in a dysoxic-anoxic shallow marine environment at the Andariyeh stratigraphic section, central Alborz Mountains. در مطالعۀ حاضر، مدل اکوگروه‌های اسپورومورفی (Sporomorph EcoGroups: SEGs) و جوامع گیاهی مرتبط با آن و همچنین پالینوفاسیس برای بازسازی پالئواکولوژی سازند دلیچای در برش چینه‌شناسی اندریه در شمال‌شرق روستای اندریه، البرز مرکزی استفاده شد. بر اساس اطلاعات مربوط به اکوگروه‌های اسپورومورفی در رسوبات مطالعه‌شده، نسبت کم جوامع گیاهی Upland/Lowland و نسبت زیاد جوامع گیاهی Lowland/Coastal + Tidal و درصد کم جامعۀ گیاهی Upland SEG گویای کم‌بودن نسبی سطح آب دریا در ناحیۀ مطالعه‌شده و رسوب‌گذاری در محیط کم‌عمق است؛ همچنین نسبت زیاد اسپورومورف‌های warmer/cooler و نسبت کم اسپورومورف‌های drier/wetter، آب‌و‌هوای گرم و مرطوب در زمان تشکیل رسوبات سازند دلیچای در برش چینه‌شناسی مطالعه‌شده را نشان می‌دهد. نتایج ترسیم نمودارهای مربوط به پالینوفاسیس در برش چینه‌شناسی اندریه نیز محیط ساحلی کم‌عمق، کم‌اکسیژن با سرعت رسوب‌گذاری کم را برای سازند دلیچای معرفی می‌کنند که به‌خوبی با نمودارهای اسپورومورفی (SEGs) آن مطابقت دارد.

https://jssr.ui.ac.ir/article_24387_f7f4a67a06e5cc849e2925082262ee50.pdf

دانشگاه اصفهان پژوهش های چینه نگاری و رسوب شناسی 2008-7888 36 1 2020 03 20 Ordovician conodonts of the Katkoyeh formation in the Kuh-e-Bonorg section, Kalmard Horst (west of Tabas) کنودونت‌های اردوویسین سازند کتکویه در جنوب کوه بنرگ، فرازمین کلمرد (باختر طبس) 61 88 24418 10.22108/jssr.2020.119847.1125 FA محمد نژادعباس دانشجوی کارشناسی ارشد چینه‎نگاری و دیرینه‎شناسی، دانشگاه فردوسی مشهد، مشهد، ایران عباس قادری استادیار گروه زمین شناسی - دانشگاه فردوسی مشهد - مشهد - ایران هادی جهانگیر گروه زمین شناسی، دانشگاه گلستان، گرگان، ایران علیرضا عاشوری استاد، گروه زمین شناسی، دانشگاه فردوسی مشهد، مشهد، ایران Journal Article 2019 10 28 Abstract In this research, Ordovician conodonts obtained from the sedimentary succession of the informal Katkoyeh formation is studied in a stratigraphic section at the south of Kuh-e-Bonorg, eastern flank of Kalmard Anticline in the west of Tabas (Central Iran). The formation which is partly equivalent to the succession of the Shirgesht Formation in Tabas Block is unconformably overlaid the Kalmard Formation (attributed to the Neoproterozoic) and disconformably overlain by the Carboniferous Gachal formation. The Katkoyeh formation with 214.8 meter thickness is divided into three lithostratigraphic members including the Lower Sandstone (mostly quartzarenite to litharenite), Middle Shale (red to green shales interbedded with some dolomitic and calcareous sandstones, in laminated wavy stromatolite structure at the base) and Upper Carbonate (limestones, dolostones and marls). The section was sampled bed by bed for conodont studies so that 80 samples have been selected, however only seven of them were productive. Within the selected samples, six genera and 14 species of coniform and ramiform conodont elements are determined, a few of them are reporting for the first time from Iran. The obtained conodonts demonstrate the faunal assemblages equal to the proteus, elegans-evae and diprion Zones which confirm the age of Early Ordovician (late Tremadocian–Floian) for the studied section. The whole conodont material display a faunal affinity with the Baltoscandic and Argentina paleobiogeographic provinces. Keywords: Conodont, Floian, Katkoyeh formation, Ordovician, Tremadocian. Introduction In spite of the moderately -exposed outcrops of the Ordovician successions throughout the country, most of the stratigraphical studies in Iran are focused on Alborz Range (e.g.; Gansser and Huber 1962, Muller 1973, Ghavidel-Syooki 2006, Ghobadi Pour et al. 2007, 2011; Jahangir et al. 2016) and the appropriate data from the other regions are restricted to a few published reports (e.g.; Ruttner et al. 1968, Aghanabati 1977, Hamedi 1995, Ghaderi et al. 2008). Especially our knowledge is very little about the conodont contents of the Ordovician rocks in Iran. The Ordovician sedimentary succession in the north of Tabas in central Iran have been introduced as the Shirgesht Formation by Ruttner et al. (1968). The rock sequences of this formation composed of brown, cream, and green to red limestones, shales and partly sandstones with hardly more than 800 m in thickness (Ghobadi Pour et al. 2006). Lithostratigraphically, the Ordovician sedimentary interval in adjacent Kalmard Block (Aghanabati 2010) is different, includes more siliciclastic rocks somewhat carbonate beds in upper part. These succession has been considered as the Katkoyeh formation by Hamedi and Wright (1992). The less known Katkoyeh formation as an informal stratigraphic rock unit in central Iran has been regarded to Arenigian to Ashgillian in the type area in Kerman region, but the age of the formation in the Kalmard type region is dissimilar in different studies. In the current research we have looked for the succession Katkoyeh formation in a section at the south of Kuh-e-Bonorg, eastern flank of the Kalmard anticline, from the age dating view, based on the conodont contents. Material & Methods In the Kuh-e-Bonorg section, 80 rock samples were collected bed by bed for conodont content while only seven of them were productive. For this purpose, sandy limestones, dolomitic limestones and pure limestones with about 3–5 kg were dissolved by 10% formic acid and 20% acetic acid following the standard procedure for conodont extraction (e.g., Jeppsson & Anehus, 1995). Residue washed on appropriate clean 18 and 230 mesh sieve-stack (0.85 to 0.063 mm). The extracted conodont collections stored in the Ferdowsi University of Mashhad, Iran under the collection name with the FUM#MC prefix. Discussion of Results & Conclusions The Katkoyeh formation in the south of Kuh-e-Bonorg section is unconformably overlaid the Neoproterozoic rocks attributed to the Kalmard Formation and disconformably overlain by the Carboniferous Gachal formation. The Katkoyeh formation of 214.8 meter thickness in the studied area is divided into three members such as the Lower Sandstone (mostly quartzarenite to litharenite), Middle Shale (red to green shale interbedded with some dolomitic and calcareous sandstone, in laminated wavy stromatolite structure at the base) and Upper Carbonate (limestones, dolostones and marls). Among the seven fossiliferous beds, we obtained the index conodonts of Lower Ordovician which belong to six genera and 14 species of coniform and ramiform elements. The assemblage is correlative with the same collections from the Baltoscandic and Argentina paleobiogeographic provinces (e.g.; Mannik and Virra 2012; Voldman ‌‌‌‌‌‌et al. 2017). The distribution of taxa in the stratigraphic succession is variable, in abundance of elements as well as in the number of taxa. The oldest conodonts in the section, Drepanodus arcuatus and Drepanoistodus costatus, come from the dolostones and dolomitic limestones of uppermost Tremadocian-early Floian proteus Zone (equivalent to Acodus apex Zone in NW Argentina Province) the sample MC208B. The next fossiliferous bed, MC232, comprises Acodus triangularis, Acodus cf. deltatus, Drepanoistodus cf. nowlani, Drepanoistodus cf. bassiovalis, Drepanoistodus bassiovalis and Gothodus costalatus which confirm Floian elegans - evae Zones (equivalent to Gothodus vetus–Gothodus andinus Zones in NW Argentina Province). The last productive beds, MC263–MC265, contain Trapezognathus diprion as the index taxon for upper evae Zone (equivalent to Trapezognathus diprion Zone in NW Argentina Province). This species confirm the age of late Floian for the uppermost part of the Katkoyeh formation in the Kuh-e-Bonorg section. در پژوهش حاضر، کنودونت‌های اردوویسین به‌دست‌آمده از توالی‌ رسوبی سازند غیررسمی کتکویه در برش چینه‌شناسی جنوب کوه بنرگ، یال خاوری تاقدیس کلمرد در باختر شهرستان طبس (ایران مرکزی) مطالعه شدند. سازند کتکویه در این برش با ناپیوستگی زاویه‌دار روی سازند کلمرد (منتسب به نئوپروتروزوئیک) قرار گرفته و خود با ناپیوستگی فرسایشی با واحد‌های سنگی کربناتۀ سازند گچال به سن کربنیفر پوشیده شده است. این سازند در برش یادشده با 8/214 متر ضخامت به سه عضو مختلف شامل عضو ماسه‌سنگ زیرین، عضو شیل میانی و عضو کربنات بالایی تقسیم می‌شود. در نمونه‌های برداشت‌شده از توالی یاد‌شده، 6 جنس و 14 گونۀ مختلف از کنودونت‌های مخروطی و شاخه‌ای شناسایی شدند که برخی از آنها برای نخستین‌بار از ایران گزارش می‌شوند. مجموعه کنودونتی موجود یادآور حضور تجمع‌های فونی معادل با بایوزون‌های proteus، elegans-evae و diprion به سن اردوویسن پیشین (ترمادوسین پسین- فلوین) است و از دیدگاه زیست‌جغرافیای دیرینه با حوضۀ بالتواسکاندیک و آرژانتین قرابت فونی دارد.

https://jssr.ui.ac.ir/article_24418_983702dca8b8f99fcd0532e4ad1a0168.pdf

دانشگاه اصفهان پژوهش های چینه نگاری و رسوب شناسی 2008-7888 36 1 2020 03 20 Biostratigraphy of the Upper Devonian–Lower Carboniferous deposits in Til-Abad section, northeast Shahrud, Eastern Alborz زیست‌چینه‌نگاری نهشته‌های دونین پایانی- کربنیفر آغازین در برش تیل‌آباد، شمال‌شرق شاهرود، البرز شرقی 89 114 24327 10.22108/jssr.2020.119411.1120 FA طاهره پرویزی دانشجوی دکتری چینه و فسیل شناسی،گروه زمین شناسی، دانشگاه اصفهان، ایران علی بهرامی دانشیار گروه زمین شناسی، دانشگاه اصفهان، ایران ساندرا کایسر موزه تاریخ طبیعی، اشتوتگارت آلمان پیتر کونیگشوف موزه تاریخ طبیعی فرانکفورت، آلمان Journal Article 2019 09 28 Abstract The biostratigraphy of Devonian–Carboniferous (D/C) boundary of Til-Abad section in Eastern alborz is carried out in this study. The studied section is located about 85 km of northeast Shahrud city and close to the Shahrud–Azadshahr road. The uppermost sediments of Devonian and lowermost Carboniferous strata in Til-Abad section (467 m thick) systematically studied and in general led to discrimination of seven following zonal boundaries: Bispathodus aculeatus aculeatus zone, Bispathodus costatus zone, Bispathodus ultimus zone, ?praesulcata zone, ckI, sulcate zone, typicus Zone and anchoralis- latus Zone. The D/C transition interval contains a bioclastic limestone and a coaly shale bed (3 cm thick) with interbedded of very thin gypsum layer. The first horizon of Carboniferous strata is begun with grey marls interbedding fossiliferous limestone. This unit has large amounts of very small corals and brachiopods with high preservation. Interpreted conodont data shows lack of kockeli Zone at the D/C boundary and Carboniferous deposits disconformably overlays the Devonian deposits of the Khoshyeilagh Formation. Keywords: Biostratigraphy, Late Devonian, Early Carboniferous, Devonian–Carboniferous boundary, Hangenberg Crisis, Til-Abad, Eastern Alborz. Introduction Conodonts have been studied by paleontologists as a very important tool for identifying and defining the D/C transition and for partial investigation of the Hangberg event (Ziegler 1962a; 1969; Sandberg et al. 1978; Ziegler and Sandberg 1990; Paproth and Streel 1984; Corradini 2003; Kaiser and Corradini 2008; Kaiser et al. 2009; Corradini et al. 2011; Hartenfels 2011; Corradini et al. 2016; Spalletta et al. 2017). After a prolonged period of warm climate from Silurian to the late Frasnian, in the Famennian regime, global climate change caused a decrease in temperature and environmental changes from greenhouse to icehouse condition (Caputo et al. 2008; Isaacson et al. 2008; Streel et al. 2000). But again in the late Famennian world climate was warmed abruptly and this warming continued until early Carboniferous, resulting in a sudden change in temperature leading to the Hangenberg Event on the D/C boundary. (Walliser 1984; Caplan et al. 1996; Caplan and Bustin 1999; Kaiser et al. 2006, 2011; Marynowski and Filipiak 2007; Marynowski et al. 2012; Kumpan et al. 2014). This increase in global temperatures triggered sea level rise, creating eutrophic conditions, anoxic conditions, increased buried carbon, the formation of the dark shale (Hangenberg Black Shale) and a reduction in shallow and especially deep marine organisms (Caplan et al. 1996; Caplan and Bustin 1999; De Vleeschouwer et al. 2013). However, this part of the Hangberg event in some sections, particularly Poland (Marynowski et al. 2012), is associated with volcanic activity and acidic magmatic intrusion into the ocean that contributed to the creation of anoxic to bioxigenic conditions. In most of the studied global sections, a Hangenberg sandstone horizon occasionally several centimeters thick can sometimes be observed following sudden anoxic events and the formation of dark shales due to sudden cooling. Therefore, global sea level fall happened at the D/C boundary (Isaacson et al. 2008; Wicander et al. 2011). As a result of the Hangberg event, the late palmatolpid and Icriodid conodonts went generally extinct (Ziegler and Sandberg 1984), but species of siphonodelids and protogonatoids were less severely damaged and entering Carboniferous, however, these conodonts were able to recover quickly and to prosper after the extinction event with their maximum reproduction strategy and reduced size and diversity. Some researchers believe that one of the reasons for this high rate of extinction at the D/C boundary is due to the vulnerability of the bio-fauna that began to recover and flourish after the significant extinction of the Frasnian–Famennian boundary but still lacked the ability to tolerate the environmental change during Hahenberg event (Morrow et al. 1996). In Iran, Devonian-Carboniferous successions are found in limited areas, but their distribution is more extensive and widespread in eastern and central Alborz and central Iran (Wendt et al. 2005). However, the presence of these deposits in different structural blocks with different depositional environments have led to different sedimentary sequences, facies and bio-fauna (Ashuri 1990, 1997, 1998, 2001, 2002, 2004, 2006; Bahrami et al. 2011; Habibi et al. 2008; Sardar Abadi et al. 2015; Yazdi 1999, Yazdi and Turner 2000; Wendt et al. 2002, 2005). The main purposes of this study are to summarize a detailed stratigraphy below and above the D/C boundary in the Til-Abad section on the basis of conodonts according to new global zonation. Material &Methods During field work, 467 m of the Upper Devonian–Lower Carboniferous successions at Til-Abad section has been measured and samples and about 93 conodont samples (3–4 kg each) were collected. The samples were processed with diluted acetic/formic acid (20%). The conodonts were extracted from residues by hand picking and heavy liquid technique at the University of Isfahan, I.R. Iran and also State Museum of Natural History Stuttgart, Germany. Discussion of Results &Conclusions Tilabad Abad section is located about 85 km from Shahrud city, near Shahrud–Azadshahr Road, adjacent to Til-Abad village in East Alborz structural zone. Geographical coordinates of the base and top of this studied section are: N: 36° 55' 46.58", E: 55° 26' 54.07" base and, N: 36° 55' 46.58", E: 55° 26' 54.07" top. This section includes Late Devonian uppermost sediments of Khoshyeilagh Formation (322 m thick) and the lowermost Carboniferous of Mobarak Formation (145 m thick), which is subdivided into eight lithological units (units A to H). The conodont zonation scheme proposed by Corradini et al. (2016) and Spalletta et al. (2017) for the Upper Devonian and Lower Carboniferous strata were utilized for lower part of the Til-Abad section in this study. According to these conodont zonations, Protognathodus kuheni is considered as the base of the Carbonoferous. However, due to the lack of Protognathodus in the Til-Abad section, we used conodont zonations of Kaiser et al. (2009) to define D/C boundary based on the appearance of Siphonodella praesulcata and Siphonodella sulcate. TheZiegler and sandberg (1990) biozones were used for the highest part of this section. Totally seven bio-intervals have been discriminated in the Til-Abad section: Bi. aculeatus aculeatus Zone, Bi. costatus Zone, Bi. ultimus Zone, The ?praesulcta Zone, The Costatus-kockeli interregnum (CKI), and the sulcata Zone, typicus Zone, anchoralis- latus Zone.It should be noted that in the studied section in the strata about 41.5 m thick consisting of dark gray to shale, yellow to cream, yellow shale with layers of gray to brown limestone, no conodont fossils were found between Siphonodella sulcata biozone and typicus biozone. Therefore, the biozones of duplicata, Sandbergi, Lower crenulata, isosticha-Upper crenulata cannot be recovered between siphonodella sulcata and typicus zones. This distance is considered equivalent to the barren zone. The reason for the lack of these biozones may have been due to facies changes or tectonic structures such as faults in the area. Despite intensive sampling in this study, no latest Famennian kockeli Zone was recognized at the studied section implying the presence of disconformity and discontinuity of deposition در پژوهش حاضر، برش تیل‌آباد در زون ساختاری البرز شرقی ازنظر زیست‌چینه‌نگاری نهشته‌های گذر دونین-کربنیفر مطالعه و بررسی شد. این برش در 85 کیلومتری شهرستان شاهرود و در کنار جادۀ شاهرود- آزادشهر قرار دارد. بررسی‌های کنودونتی سیستماتیک حدود 467 متر از نهشته‌های بالاترین بخش‌های دونین بالایی و بخش‌های آغازین کربنیفر زیرین با‌توجه‌ به بایوزون‌های استاندارد جهانی به شناسایی 7 بایوزون به شرح زیر منجر شد: Bispathodus aculeatus aculeatus Zone, Bispathodus costatus Zone, Bispathodus ultimus Zone, ?praesulcata Zone, ckl, sulcata Zone, typicus Zone, anchoralis- latus Zone گذر دونین- کربنیفر در برش تیل‌آباد بر یک واحد سنگ‌آهک بیوکلاستی در آخرین بخش فامنین پسین و یک لایه شیل تیرۀ زغالی با ضخامت حدود 3 سانتی‌متر دارای ورقه‌های نازک ژیپسی در مرز دونین- کربنیفر منطبق است. نخستین افق‌های کربنیفر با واحدی از شیل‌های خاکستری دارای میان‌لایه‌های سنگ‌آهک فسیل‌دار آغاز می‌شود؛ این واحد مقادیر فراوانی از مرجان‌ها و بازوپایان بسیار ریز با حفظ‌شدگی بسیار خوب متعلق به کربنیفر پیشین دارد. مقایسۀ زیست‌چینه‌نگاری برش مطالعه‌شده با بایوزون‌های استاندارد جهانی ارائه‌شده برای گذر دونین- کربنیفر به شناسایی ناپیوستگی هم‌شیب در این مرز و نبود kockeli Zone از آخرین بایوزون‌های فامنین پسین منجر شد.

https://jssr.ui.ac.ir/article_24327_5e61feb2ec268a6be2f26cd5c530747b.pdf

دانشگاه اصفهان پژوهش های چینه نگاری و رسوب شناسی 2008-7888 36 1 2020 03 20 Microfacies, sedimentary environmental model and relative sea level change of marly strata of the Qom Formation in Zarrin-Abad section, South of Zanjan ریزرخساره‌ها، مدل رسوبی و نوسان‌های نسبی سطح آب در توالی‌های مارنی سازند قم در برش زرین‌آباد، جنوب زنجان 115 134 24439 10.22108/jssr.2020.120140.1128 FA جواد ربانی گروه زمین شناسی، دانشکده علوم، دانشگاه زنجان، زنجان، ایران. مجید میرزایی عطاآبادی گروه زمین شناسی، دانشکده علوم، دانشگاه زنجان، زنجان ، ایران الهام شاهسواری گروه زمین شناسی، دانشکده علوم، دانشگاه زنجان، زنجان، ایران. Journal Article 2019 11 27 Abstract In order to reconstruct the sedimentary environment of marly strata related to the upper parts of Qom Formation, one stratigraphic outcrop have been studied. Studied section is located in the Zarrin-Abad area (South of Zanjan) and is composed of 135 meters of marls and argillaceous limestones. Theses strata are limited by thick bedded limestone (related to the F Member of the Qom Formation) at the base. There is a thick bed of evaporate layer at the top of these strata with sharp boundary that can be stratigraphically related to the Upper Red Formation. Based on petrographic and texture studies, eight microfacies have been identified. These microfacies are related to the distal parts of inner shelf, patch reef, slope, toe of slop and deep shelf sub environments. Based on microfacies analysis we can propose an open shelf as sedimentary environment for these strata. Relative abundance of allochems show one cycle (rise and fall) in relative sea level along the stratigraphic column that can be correlated with eustasy curve. Keywords: Microfacies, Sedimentary model, Qom Formation, Zarrin-Abad, Zanjan. Introduction The Qom Formation (Oligocene–Miocene) in central Iran is composed of carbonate and silisiclastic strata that is related to the lagoon, reef and basin sedimentary environments (Reuter et al. 2009). Due to the hydrocarbon potential, this formation has been considered by many geologists. Different sedimentary environment (ramp and/orshelf) have been proposed for this formation. Thus, this study try to reconstruct the sedimentary environment for these strata in the south of Zanjan to complete the comprehensive plan for the sedimentary environment of the Qom Formation. This formation in the studied section (Zarrin-Abad) is unconformably underlain by silisiclastic strata of the Lower Red Formation (Aalipour et al. 2017) and overlain (covered boundary) by the evaporitic package of Upper Red Formation. This study focused on upper parts of Qom Formation (marls and argillaceous limestones) in order to reconstruct sedimentary environment. Material & Method One stratigraphic section has been sampled in the South of Zanjan (Sothwest of Zarrin-Abad). Forty two samples from 135 meters of marls and argillaceous limestones (Upper parts of Qom Formation) have been collected and thin sections were prepared. Sampling intervals were about three meters in average and included hard and semi-hard sediments. The microfacies analysis using polarized microscope have allowed the reconstruction on carbonate environment of upper parts of the Qom Formation in this section. Carbonate rock classification, facies study and environmental interpretation on thin sections was based on Dunham (1962) and Flugel (2010). All thin sections have been housed in Paleontological Laboratory, Department of Geology, University of Zanjan. Discussion of Results & Conclusions Biostratigraphic studies confirm a Burdigalian age for these strata based on two index fossils (Borelis meo curdica, Meandropsina Iranica). One biozone has been identified based on first occurrence of Borelis melo curdica in the base of section (S1) and last occurrence of Meandropsina Iranica in the top of section (S39). This biozone can be correlated with (Adams and Bourgeois 1967) and (Daneshian and Ramezani Dana 2019) zonations. Microfacies analysis lead to identification of eight microfacies (1- Bioclast benthic foraminifera algal grainstone, 2- Coral boundstone, 3- Bioclast wackestone, 4- Sandy bioclast grainstone, 5- Sandy bioclast packstone, 6- Bioclast mudstone, 7- Pelagic mudstone/wackestone and 8- Pelagic packstone) related to the middle to outer carbonate shelf environment. Coral reef facies in lower parts of studied section can approve a carbonate shelf as sedimentary environment. Moreover, bioclast particles that consist of corals, benthic foraminifera, algae and some other fossils beside coral boundstone facies show fore reef facies in front of the platform margin. Based on presence of clastic particles in pelagic facies, we can conclude that there were some channels in coral reef areas that connect back reef environments to the open marine areas. Based on field observation and microfacies analysis, we proposed non-rimmed carbonate shelf as sedimentary environment for the studied strata. Based on quantitative analysis on environmental data, most of samples (strata) are related to the deep shelf environment. Quantitative analysis diagrams (allochems percentage) shows in each samples that there were rising trend in relative sea level from the base of section to the middle part. Following this trend the falling trend towards the end of the section have been recorded. This trends can be correlated with the global sea level changes during this time (Burdigalian). Thus it can be concluded that the Burdigalian basin in this area had been connected to the open oceans. به‌منظور بازسازی محیط رسوبی دیرینۀ توالی‌های مارنی انتهای سازند قم، یک برش چینه‌شناسی سطح‌الارضی در منطقۀ جنوب زنجان مطالعه شد. این برش در منطقۀ زرین‌آباد شامل 135 متر توالی‌های مارنی و آهک رسی مربوط به بخش‌های انتهایی سازند قم است که روی توالی‌های کربناتۀ ضخیم‌لایۀ عضو F این سازند قرار گرفته‌اند. یک واحد ضخیم‌لایۀ تبخیری به‌طور ناگهانی روی توالی‌های یادشده قرار گرفته است که می‌توان آن را به سازند قرمز بالایی نسبت داد. مطالعۀ 42 مقطع نازک میکروسکوپی از این توالی‌ها به شناسایی و تفکیک 8 ریزرخساره منجر شد که مجموع این رخساره‌ها، محیط رسوبی شلف مرتبط با دریای آزاد (Non-rimmed shwlf) شامل زیرمحیط‌های بخش‌های دور از ساحل شلف درونی، ریف، شیب قاره، بخش‌های انتهایی شیب قاره و شلف عمیق را برای این توالی‌ها پیشنهاد می‌کند. بررسی نمودارهای فراوانی نسبی آلوکم‌ها و تغییرات رخساره‌ای در مجاورت ستون چینه‌شناسی، چرخۀ نوسان افزایشی و کاهشی سطح آب دریا به‌طور نسبی در طول ستون چینه‌شناسی را نشان می‌دهد؛ این موضوع با نمودار جهانی نوسان‌های سطح آب دریا در این محدودۀ سنی منطبق است.

https://jssr.ui.ac.ir/article_24439_2ec6dff094d01907b4689b7af3ad427f.pdf