M. Heydari; Sharafi M.
Abstract
The use of remote sensing combined with field surveys can be used as an economic approach to detect the areas that are susceptible to the influx of water into tunnels. This study aims at investigating potential zones of groundwater influx in part 1-A of the Nosoud water-transport tunnel located in the ...
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The use of remote sensing combined with field surveys can be used as an economic approach to detect the areas that are susceptible to the influx of water into tunnels. This study aims at investigating potential zones of groundwater influx in part 1-A of the Nosoud water-transport tunnel located in the NW of Kermanshah province. Stratigraphic units of the area are composed of limestone and shale layers, which have formed alternating hard and soft sequences at the tunnel site. Fractured brittle limestone layers alternating with impermeable shale layers are the most important factor controlling the influx of water into the Nosoud tunnel. The danger of possible mine explosions prevented us from a survey along the whole length of the tunnel. Hence we classified these lithologies into two types labeled as Li and Sh which representing limestone and shale respectively. In order to explore layers that could potentially lead to water influx, we used ASTER satellite images to analyze the geohydrologic evidences across the area. Results suggest that the tunnel has a high risk of groundwater influx in places where the Li3 and Li-Sh3 units are encountered. Moreover, observations during tunnel excavation show that the major cause of water influx into the tunnel are preferentially concentrated in zones where hard layers with open fractures are crossed. This is considerably compatible with the results of satellite image processing model.
R. Haftlang; M. Afghah; S. A. Aghanabati; M. Parvaneh Nezhad Shirazi
Abstract
Lithological and biological Sequences of Cretaceous in Bahar section, Located in South Esfahan (147 m. true thickness) include grayish olive green pencil- like shales containing Budantysras Ammonites (Albian) interbedded with limy shales. which are covered by glauconitic Sandy Limestone (Early Turonian) ...
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Lithological and biological Sequences of Cretaceous in Bahar section, Located in South Esfahan (147 m. true thickness) include grayish olive green pencil- like shales containing Budantysras Ammonites (Albian) interbedded with limy shales. which are covered by glauconitic Sandy Limestone (Early Turonian) (with erosional discontinuity). These sandy limestones are wackestone and rarely greenstone, according to Dunham classification. Based on Biozone divisions, this unit is related to Biozone No. 27 presented by Wynd (1965) and it is equivalent to Sarvak Formation in Zagros. Marly limestone and limestone containing Inoceramus bivalve interbedded with marl dating back to Late, Middle Touronian- Late Touronian- Coniacian to Early Santonian are younger equivalents of this section which can be equaled to Surgah Formation. According to Biozone divisions, this unit is equivalent to Biozone No. 28 presented by Wynd (1965) and also based on Dunham classification, the unit is packestone and partly boundstone. The lower Contact of the unit is Concordant and Continuous with glauconitic sandy limestone and its upper Contact is Continuous and Concordant with marl and interbeddings of Limestones dating back to Santonian- Campanian. By comparing Bahar Section with South eastern Lorestan section (Poshte jangal anticline), (Azadbakht, 2015), the following results were obtained: From Litho/bio stratigraphical view, thick to thin-bedded Limestones (Light to dark gray) interbedded with marl in Poshte jangal anticline are Correlated with Inoceramus limestone and marly Limestone interbedded with marl in Bahar Section. They are dated back to EarlyTuronian to Early Campanian.Due to Strong similarity of Lithostratigraphy and biostratigraphy between Bahar section located in Southern Esfahan (Central Iran) and section of Poshte jangal anticline located in Southeast of Lorestan, it can be deducted that a branch of Lorestan Sea has advanced in Turonian- Coniacian times and some parts of Southern Esfahan has been covered by the sea.
Stratigraphy and Palaeontology
A. Abdolnia; I. Maghfouri Moghaddam; D. Baghbani
Abstract
The Shahbazan Formation deposited in the Lorestan foreland basin and northeastern part of Dezful embayment zone during the Middle-Late Eocene age. In order to study the stratigraphy of the Shahbazan Formation, four surface sections of this formation in northeastern flank of Langar anticline, southeastern ...
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The Shahbazan Formation deposited in the Lorestan foreland basin and northeastern part of Dezful embayment zone during the Middle-Late Eocene age. In order to study the stratigraphy of the Shahbazan Formation, four surface sections of this formation in northeastern flank of Langar anticline, southeastern flank of Chenareh anticline, northeastern flank of Maleh Kuh anticline and southwestern flank of Poshte-Jangal anticline, have been selected. The Shahbazan Formation in Langar and Chenareh sections is composed of limestone with intercalation of dolomite. In other parts of the Lorestan such as Maleh kuh and Poshte Jangel, it consists of dolomite and intercalations of limestons. In these areas, the Shahbazan and Asmari formations form a prominent topographic unit and separating their boundary is often difficult to place, thus making it necessary to map the two formations as one unit. In this case, the two names are hyphenated as Shahbazan- Asmari Formation. According to study of benthic foraminifera in Chenareh and Langar sections, two biozone have been distinguished. The age of the Shahbazan Formation in these areas is determined as Middle- Late Eocene (Bartonian- Priabonian). In the Maleh Kuh section, the lower part of the Shahbazan- Asmari Formations is dolomitic but in the upper part it contains limestone beds with foraminifera that belong to two assemblage zones, in Aquitanian- Burdigalian age. In the Poshte Jangal section, the lower and middle parts of Shahbazan- Asmari formations are dolomitic but the upper part contains limestone beds with rare foraminifera which have been reported at the Chattian- Burdigalian beds of the Asmari Formation.
Z. A. Pur-Abrishami; A. H. Kokabi-Nezhad; G. R. Zare; O. Dabiri
Abstract
Maragheh informal Formation is widely extended on the Sahand hillside and Maragheh city. Based on lithology and sedimentary facies, Maragheh Formation is divided into two members: lower member in the studied area (Mordagh area - Aghajery) consists of marl, tuff, tuffaceous ...
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Maragheh informal Formation is widely extended on the Sahand hillside and Maragheh city. Based on lithology and sedimentary facies, Maragheh Formation is divided into two members: lower member in the studied area (Mordagh area - Aghajery) consists of marl, tuff, tuffaceous sandstone with several fossiliferous layers. Upper member has more extent and thickness than the lower member and the facies variation are accompanied by increase of tuffaceous layers with diatomit and fish debries. In the Gorg Darreh –Mordagh area four geologic sites were excavated and investigated for vertebrate fossils. The samples obtained in this study from above mentioned sites consist of Ivory of mastodont, Ivory of phiomia, Monkey teeth, radius and ulana bones of elephant, cervid, gazelle and hipparions. The sequence of Maragheh Formation mostly consists of fluvial deposits, therefore its dating is difficult. However, it displays different ages from 7Ma to 12.5Ma respectively based on the vertebrate fossils such as hipparion sp. ,.
