Archive \ Volume.8 2019 Issue 4

Sr-Nd Isotope Constraints of Hezar Igneous Complex (south of ‎Kerman- Iran) - as a Part of Urumieh-Dokhtar Magmatic Arc

Mohammad Noorizadeh , Abbas Moradian , Hamid Ahmadipour , Mohammad ‎Reza Ghassemi , José Francisco Santos ‎‏
Abstract

The Hezar Igneous Complex (HIC) in the south-eastern part of Urumieh-Dokhtar magmatic arc, is the most prominent magmatic feature in the Kerman Porphyry Copper Belt, near Rayen, south of Kerman. It is indicated that the possible place of the vent is in Jalas Mountain which has been split later by the Sabzevaran fault into Minor and Major Jalas. The sub-alkaline rocks of this complex are mainly composed of different pyroclastic and lava flow rocks, acidic to basic in composition. Positive Epsilon Nd values and low Sr in HIC, besides TDM 0.6-0.7 Ga indicates formation from partial melting of lithospheric mantle sources which is modified with previous subduction components. Positive epsilon Nd indicates that these rocks have been originated from evolved magmas without assimilation of crustal materials. All of the samples except two cases are far from mantle array which indicates that they are located in mantle wedge over the subduction zone and subjected to some increasing in 87Sr/86Sr ratios. The depicted isochron for three related samples indicates an age of 47±5 Ma with MSWD=0.44 which is an indication for the main magmatic activity of this complex. But two other samples give an unreliable age of 6.4 Ma for some intrusive bodies (dikes) in Jalas which is the last phase of magmatism in HIC.


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