Maryam Honarmand; Mohsen Moayyed; Ahmad Jahangiri; Jamshid Ahmadian; Noushin Bahadoran
Volume 1, Issue 3 , December 2010, , Pages 65-88
The Natanz plutonic complex is located 120 km north of Isfahan and in the Orumieh - Dokhtar magmatic belt. These Oligocene - Miocene plutons are intruded into the volcanics of Eocene. ...
The Natanz plutonic complex is located 120 km north of Isfahan and in the Orumieh - Dokhtar magmatic belt. These Oligocene - Miocene plutons are intruded into the volcanics of Eocene. Based on petrographic studies, the Natanz complex is composed of six types of rocks, including gabbro, diorite, quartz-diorite, quartz-monzonite, granodiorite and granite. Field, mineralogy and geochemical studies indicate that the parental magma of this complex is I-type in nature, calc-alkaline and meta-aluminous. Magma produced gabbro resulted from melting of metasomatized upper mantle which have undergone differentiation prior to emplacement. The parental magma of granitoid rocks is diorite that produced from mixing of mantle-derived mafic magma and crustal melting magma. The geochemical characteristics of rare earth elements are comparable to other subduction-related magmatic rock suites. The flat REE pattern in these magmas may require their derivation by partial melting from a garnet-poor source. Petrological evidence show that fractional crystallization from dioritic magma to monzogranitic magma was the main role in the genesis of these rocks. Tectono-magmatic setting of this complex may be subduction related magmatism or post-collisional magmatism due to extensional phases after collision of Arabic and Central Iran microcontinent.