Paper Information

Journal:   PETROLOGY   WINTER 2016 , Volume 6 , Number 24; Page(s) 87 To 113.
 
Paper: 

RB/SR AND SM/ND ISOTOPE GEOCHEMISTRY AND PETROGENESIS OF MISHU GRANITOID ROCKS, NORTHWEST OF IRAN

 
 
Author(s):  SHAHZEIDI MALIHE, MOAYYED MOHSEN*
 
* DEPARTMENT OF EARTH SCIENCES, FACULTY OF NATURAL SCIENCES, UNIVERSITY OF TABRIZ, TABRIZ, IRAN
 
Abstract: 

Abstract The Mishu granitoids occur in northwest of Central Iran and are part of the Khoy-Takab Precambrian metamorphic belt. Based on petrographic studies, this complex comprises several intrusions of granitic rocks ranging in composition from diorite to leucogranite. Geochemical studies indicate these granitic rocks can be divided into the three groups which have undergone a complex history of magmatic process. I-type and S-type granitoidic rocks and leucogranites generally having features typical of medium to high-K calc-alkaline to shoshonitic rocks. Primitive mantle-normalized trace element spider diagrams display enrichment in LILE and depletion in some HFSE which is typical of an enriched mantle source. Rb-Sr and Pb-Pb isotopic data determine the ages of 530±30 and 500±74 Ma for the rocks studied. S-type granites show high (87Sr/86Sr)i values between 0.7081 and 0.7104 and negative eNd values -4.18 to -4.72, whereas I-type granites have a much wider range in eNd of -0.8 to -4.3 and lower (87Sr/86Sr)i of 0.704867 to 0.708046. Initial eNd values for leucogranites range from +0.98 to +1.25. However, their variable Sr and Nd isotope compositions together with major and trace element geochemistry suggest that they were produced by mixing of crustal anatectic melts with variable amounts of mantle-derived basaltic liquids. The present study, therefore demonstrates that these granitic rocks formed on an active continental margin during convergence of Centeral Iran and Alborz-Azerbaijan to Arabian platform during Precambrian (closure of branch of the Proto Tethys Ocean).

 
Keyword(s): SHOSHONITIC MAGMATISM, MAGMA MIXING, MISHU ENRICHED MANTLE, CENTRAL IRAN, UROMIEH-DOKHTAR MAGMATIC ZONE
 
References: 
  • ندارد
 
  Persian Abstract Yearly Visit 105
 
Latest on Blog
Enter SID Blog