Zircon U-Pb Ages and Magmatic History of the Kashan Plutons in the Central Urumieh-Dokhtar Magmatic Arc,Iran:Evidence for Neotethyan Subduction during Paleogene-Neogene  

作　　者：Tayebeh Khaksarc Nematollah Rashidnejad-Omran Fukun Chen Shu-Guang Song Shuang-Qing Li Majid Ghaderi 

机构地区：[1]Department of Geology,Tarbiat Modares University,Tehran 14115-175,Iran [2]School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [3]School of Earth and Space Sciences,Peking University,Beijing 100871,China

出　　处：《Journal of Earth Science》2020年第1期53-68,共16页地球科学学刊（英文版）

基　　金：The TMU Research Grant Council funded field studies;partly supported by grants from the University of Science and Technology of China,Hefei;Peking University,Beijing

摘　　要：The Kashan plutons are situated in the central part of Urumieh-Dokhtar magmatic arc recording subduction-related magmatism within the Alpine-Himalayan orogeny in Iran.These rocks consist of different calc-alkaline plutonic rocks including gabbro,gabbroic diorite,microdiorite,monzodiorite,tonalite,granodiorite,and granite.The plutons were emplaced into the Jurassic sedimentary units(Shemshak Formation)and the Eocene calc-alkaline volcanic and pyroclastic rocks.New U-Pb zircon ages show that the Kashan plutons formed during two main periods at 35.20±0.71 Ma in the Late Eocene(Priabonian)and at 18.90±0.84,19.26±0.83,19.30±1.2,and 17.3±1.8 Ma in the Early Miocene(Burdigalian).The reported events in the Kashan plutons imply the final phases of subductionrelated magmatism before the collision which happened between the Arabian and Iranian plates in the Middle Miocene.The plutonic activity in the Kashan region occurred during the transition from Eocene subduction-related setting to Middle Miocene collisional setting.The Kashan plutons are situated in the central part of Urumieh-Dokhtar magmatic arc recording subduction-related magmatism within the Alpine-Himalayan orogeny in Iran.These rocks consist of different calc-alkaline plutonic rocks including gabbro,gabbroic diorite,microdiorite,monzodiorite,tonalite,granodiorite,and granite.The plutons were emplaced into the Jurassic sedimentary units(Shemshak Formation) and the Eocene calc-alkaline volcanic and pyroclastic rocks.New U-Pb zircon ages show that the Kashan plutons formed during two main periods at 35.20±0.71 Ma in the Late Eocene(Priabonian) and at 18.90±0.84,19.26±0.83,19.30±1.2,and 17.3±1.8 Ma in the Early Miocene(Burdigalian).The reported events in the Kashan plutons imply the final phases of subductionrelated magmatism before the collision which happened between the Arabian and Iranian plates in the Middle Miocene.The plutonic activity in the Kashan region occurred during the transition from Eocene subduction-related setting to Middle Miocene collisional setting.

关 键 词：zircon U-Pb dating plutonic episodes Kashan Urumieh-Dokhtar magmatic arc Iran 

分 类 号：P619.14[天文地球—矿床学] P597.3[天文地球—地质学] P588.11