Petrology and geochemistry of volcanic rocks in south Langrood

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Research Paper 01/12/2014
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Petrology and geochemistry of volcanic rocks in south Langrood

Sedigheh Ehsani, Mohammad Ali Arian, Mohammad Hossein Razavi
J. Bio. Env. Sci.5( 6), 345-352, December 2014.
Certificate: JBES 2014 [Generate Certificate]

Abstract

This region is located 330kmfar from north of Tehran in Gilan province. According to tectono-sedimentary classification of Iran (Nabavi, 1977), this region is located in Alborz-Azarbaijan zone. The area of understudied region in Gilan province is 450 km2 that is located in south and west part of Amlash city. In this region the upper part is formed of an Ophiolite set that its uplifting time is upper Cretaceous. Constitutive rocks of this part are rocks of old ocean crust and totally consist of carbonate cretaceous sedimentary rocks, pillow basalts (include basalt, basaltic andesite, andesite and trachyte terms), delorite and gabbro dikes. Totally it can be concluded that petrologic and geochemical studies in southern of Amlash indicate a magmatic event in various tectonic environments in a way that each rift environments, active continental and intra-plate margins are acceptable for some of the samples. In the other hand, there are evidences that show magmatic differentiation and crust pollution happened in understudied rocks. Therefore, clear and detailed interpretation about tectonic environment of these magmatic events is not possible.

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