University of Isfahan Petrological Journal 2228-5210 10 4 2020 02 20 Petrography, geochemistry, tectonic setting and petrogenesis of volcanic rocks in Robaie area (South of Damghan) Petrography, geochemistry, tectonic setting and petrogenesis of volcanic rocks in Robaie area (South of Damghan) 23 44 24533 10.22108/ijp.2020.119892.1152 FA Mehdi Mahdavi Akerdi 1Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Azadeh Malekzadeh Shafaroudi 1Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran 0000-0002-7373-561x Mohammad Hassan Karimpour 1Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Behnam Rahimi 1Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Jose Francisco Santos 2Department of Geology, University of Aveiro, Aveiro, Portugal Journal Article 2019 11 20 <span>The rocks of the Robaie area located in the Torud-Chahshirin belt and south of Damghan, includes the Eocene andesite and trachyandesite rocks in which subvolcanic igneous rocks as </span><span lang="EN-ZW">stoke and dyke </span><span>with </span><span lang="EN-ZW">diorite, monzonite and monzodiorite porphyry composition</span><span> are intruded</span><span lang="EN-ZW">. </span><span>The main textures of volcanic rocks are porphyritic characterized by plagioclase, hornblende and biotite phenocrysts as well as apatite and zircon as minor minerals. </span><span lang="EN-ZW">The rocks studied are mainly of shoshonitic nature and only one sample is considered as high-K calc-alkaline. </span><span>Several line of  evidence including LILE and LREE enrichment, HREE and HFSE depletion, high Th/Yb with negative anomalies of Ti, Nb and the position of the samples on the tectonic discrimination diagrams indicate that the volcanic rocks in discussion were emplaced into the subduction zone related to an active continental margin setting. The initial ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd ratios and (εNd)_i value of andesite are 0.704445, 0.512691 and 2.29, respectively. All of these evidences confirm that the studied volcanic rocks were generated from partial melting of the mantle wedge above the subduction zone. Petrographic observations along with geochemistry of rare earth and trace elements suggest that the calc-alkaline affinity of the rocks studied and their parent magma from a subducted-related environment as well as crustal assimilation and fractional crystallization</span> <span>The rocks of the Robaie area located in the Torud-Chahshirin belt and south of Damghan, includes the Eocene andesite and trachyandesite rocks in which subvolcanic igneous rocks as </span><span lang="EN-ZW">stoke and dyke </span><span>with </span><span lang="EN-ZW">diorite, monzonite and monzodiorite porphyry composition</span><span> are intruded</span><span lang="EN-ZW">. </span><span>The main textures of volcanic rocks are porphyritic characterized by plagioclase, hornblende and biotite phenocrysts as well as apatite and zircon as minor minerals. </span><span lang="EN-ZW">The rocks studied are mainly of shoshonitic nature and only one sample is considered as high-K calc-alkaline. </span><span>Several line of  evidence including LILE and LREE enrichment, HREE and HFSE depletion, high Th/Yb with negative anomalies of Ti, Nb and the position of the samples on the tectonic discrimination diagrams indicate that the volcanic rocks in discussion were emplaced into the subduction zone related to an active continental margin setting. The initial ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd ratios and (εNd)_i value of andesite are 0.704445, 0.512691 and 2.29, respectively. All of these evidences confirm that the studied volcanic rocks were generated from partial melting of the mantle wedge above the subduction zone. Petrographic observations along with geochemistry of rare earth and trace elements suggest that the calc-alkaline affinity of the rocks studied and their parent magma from a subducted-related environment as well as crustal assimilation and fractional crystallization</span> https://ijp.ui.ac.ir/article_24533_db55e4b967e75904d503cdd92d58f74e.pdf