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CONTENTS YEAR 2019 Asian J. Exp. Sci., V 33, No. 1, 2019; 1-20
Leila Ebadi*, Seyed Mohammad Hosein Razavi and Hosein Sheikhi Karizaki
1 Department of Geology, Azad University, North Tehran Branch, Tehran, Iran
Abstract : The ophiolitic rocks from the Dizajaland area in NW Iran are a part of the non-metamorphic ophiolitic complex of SW Khoy. They are close to eastern Turkey ophiolites, ophiolites along Zagros orogen and ophiolites from the Lesser Caucasus in Armenia. The study shows that all ophiolitic units including serpentinized peridotite, gabbro, diabase, pillow lavas and deep marine sediments are present in the area, although dismembered and displaced. Microfossils in the ophiolitic pelagic limestone indicate an age of Santonian-Campanian. Whole rock chemistry of the crustal sequence rocks indicates calk-alkaline to tholeiitic nature and a mid-ocean ridge to island arc tectonic-setting. The chemistry of the mafic rocks shows a mantle source, close to E-MORB compositions. The dual nature (i.e. both island arc and MORB) for the crustal sequence rocks, based on whole rock chemistry, is taken to represent a supra-subduction setting for these ophiolites. Mineral chemistry of orthopyroxene, spinel and olivine in the peridotites confirms a supra-subduction setting with a fore-arc environment for generation of these rocks. Ophiolitic rocks from the Dizajaland area can be considered as a continuation of "Inner Ophiolite Belt" of Iran, connecting it to the Izmir-Ankara-Erzincan suture. Apparently they are obducted along the Sevan-Akera suture in Armenia as a northern continuation of the Izmir-Ankara-Erzincan suture. These ophiolitic rocks are result of an intra-oceanic subduction with late Jurassic age.
Key words : Ophiolite; supra-subduction zone; fore-arc; Neotethys; NW Iran
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Mineralogy and Geochemistry of Rhyolitic domes and Perlites in the Ghledokhtar, Northwest of Iran
Amin Allah Kamali*, Mohsen Moayyed, Amir Mohamedgol, Ali Asadi
Departmentof Geology, Faculty of Natural Sciences, University of Tabriz, Iran.
Abstract : Volcanic rocks of Ghledokhtar are located some 15 km southeast of Mianeh Township, East Azarbaijan province, northwestern Iran. Acidic rocks of the area include Oligocene rhyolite, rhyodacite, perlite and lava. Rhyolites and rhyodacites are exposed in the form of domes as well as lava flows. Perlites that occurs in the lower parts of the rhyolites and rhyodacite domes, was formed by the rapid cooling of acidic lavas and volcanic glasses such as obsidian, which later converted to Perlite in the presence of atmospheric and hydrothermal waters. Agate in Ghledokhtar area has occurs in voids inside the acidic volcanic units of Oligocene. Formation of silica in the host- and surrounding rocks including cavities may be attributed to hydrothermal gases in the region. Mineralogically the rhyolitic and rhyodacitic rocks include sanidine, quartz, plagioclase, hornblend, biotite and opaque minerals with microlithic porphyry texture. Geochemically, however, rhyolites indicate calc-alkaline nature belonging to I-rhyolites and magnetite series. The rhyolites of the area, in relation to (give details of abbreviation first) HREE in parenthesis and HFSE (same as above), are enriched in LILE (as above) and LREE (as above) but depleted in Ta and Nb as they are related to an arc system. The tectonic setting and origin show that they represent rocks that are associated with subduction and were contaminated by the upper crust. Besides, they show negative anomalies of Nb, Ta, P, Ti and Pb. Tectonic setting and discrimination diagrams point that the rocks were formed due to subduction of the neotethys beneath the central plate of Iran, in the central Iranian active continental margin.
Key words : Ghledokhtar, rhyolites, subduction, perlite.
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Mozhgan Poormansouri1, Mohammad Hossein Razavi1*, Afshin Ashja Ardalan1, Mohammad Ali Makkizadeh2, Mohammad Khalaj3
1Department, Tehran North Branch, Islamic Azad University, Tehran, Iran
Abstract : Compared to other alterations, Rare Earth Elements (REEs) do not indicate remarkable mobility in Shoja Abad Region. Low mobility of REEs and increase in heavy rare earth elements (HREEs) in the propylitic zone are associated with high pH level and low water-content of the rocks in the respective region and transfer of the respective elements to the clay minerals of the kaoline family (halloysite and kaolinite). In the region under study, depletion alteration of all REEs is observed with slight differentiation from the HREEs. This is reflective of formation of this alteration zone in an environment with high pH and temperature. Evidently, the respective conditions lead to leaching of all rare earth elements. In the vicinity of Qom-Zefreh faulting zone in the region under study, alterations can be observed resulting from geothermal solutions of rising calc-alkaline andesite magma. The most significant attribute of the respective section is presence of enclaves of oceanic crust composition (~Upper Cretaceous) and uplifting of the dark-colored masses during rise of calc-alkaline magma.
Key words : Hydrothermal alteration, Shoja Abad, Uremia-Dokhtar Belt, Qom - Zefreh Fault.
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Anjali Namdeo1 and Suchitra Banerjee2
1Govt. M.L.B. Girls College, Bhopal, India
Abstract : Present study was conducted to determine the in vivo effects of short term exposures of ethanolic leaf extract of Datura stramonium (D.s. 100 mg/l) and chlorpyriphose (0.0034 mg/l) separately and combined for 96 hours on acetylcholinesterase (AChE) activity, inhibition, and enzyme kinetics of the liver of Catla catla. This was followed by a recovery period in clean water (120 h more). Enzyme inhibitory activity was carried out by using Ellman's method (1961). Enzyme kinetics was estimated by Line Weaver Burk's plots. The results demonstrated inhition in AChE activity in the liver were ranging from 32% to 51%. Following 120 hours of recovery, AChE activity in catla liver was still different from that of controls and recovered 24.3% at the end of experiment.
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