TY - JOUR ID - 142659 TI - Tectonic environment and petrogenesis of igneous rocks of Tashvir area, Tarom mountains, northwest of Iran JO - Scientific Quarterly Journal of Geosciences JA - GSJ LA - en SN - 1023-7429 AU - Jamal Omidi, Reza AU - Hakimi Asiabar, Saeid AU - Haghnazar, Shahrooz AU - Vosoghi Abedini, Mansour AD - Department of Geology, Lahijan Islamic Azad University, Lahijan, Iran AD - Department of Geology, North Tehran Islamic Azad University, Tehran, Iran Y1 - 2022 PY - 2022 VL - 32 IS - 2 SP - 105 EP - 120 KW - Tectonic setting KW - Magmatic arc KW - Rift KW - Tarom mountains KW - Alborz DO - 10.22071/gsj.2022.305126.1936 N2 - Tarom mountains are located at the southwestern end of the Alborz mountain range with an approximate northwest-southeast direction. Tashvir region is a part of the northern margin of the Tarom mountains. Most igneous rocks in this area include basalt, andesitic basalt, and interlayers of tuff. Enrichment of LIL elements with positive anomalies of Ce, P, Sm, and depletion of Nb, Ta, Zr, Hf, and Th, elements and also K2O/Na2O and Ba/Rb ratios in the rock samples of Tashvir area, indicate magma contamination with the lower crust. The evidence of crustal contamination and the ratio of Nb/Y and Zr/Y in the samples indicate that the basalts of the Tashvir region belong to the source of the plume. Alkaline, shoshonitic, and peraluminous nature, REE enrichment (i. e. Ba, Rb, and Sr), low titanium content, origin, and depth of magma indicate they're belonging to the rift environment. In this study, in addition to determining the characteristics of igneous rocks in the Tashvir area, the results of several previous studies are plotted on the map of the Tarom mountains. Accordingly, the tectonic setting of the Tarom range is divided into two parallel sub-regions with magmatic arc and rift-type eruptions, which expansion of this rift zone has stopped before it evolve as a back-arc basin. UR - http://www.gsjournal.ir/article_142659.html L1 - http://www.gsjournal.ir/article_142659_f55995e5af9e19d7e55058faae280591.pdf ER -