Effective Processes in Evolution of Kuh-e Dom Plutonism, NE Ardestan, the using of Geochemical and Isotopic Evidence

Kananian, A.; Sarjoughian, F.; Ahmadian, J.

doi:10.22071/gsj.2011.54383

Document Type : Original Research Paper

Authors

¹ Department of Geology, School of Science, Tehran University, Tehran, Iran

² Department of Geology, Payam-e Noor University, Tehran, Iran

https://doi.org/10.22071/gsj.2011.54383

Abstract

The Kuh-e Dom intrusion is a small section of Upper Eocene Urumieh- Dokhtar magmatic belt in the Central Iran tectonic zone. This intrusion is composed of two separate phases which include an acidic and intermediate- mafic units. The acidic rocks consist of monzogranite, granodiorite, quartz monzonite and quartz monzodiorite whereas the intermediate-mafic rocks comprise gabbro, diorite, quartz diorite, monzodiorite and monzonite. Mafic microgranular enclaves of dioritic, quartz dioritic, monzodioritic and quartz monzodioritic composition are common in the acidic rocks. Based on geochemical data, magma mixing along with fractional crystallization has important role in evolution of the plutonic rocks. Also, Kuh-e Dom intrusive rocks have low TiO₂, P₂O₅ and Nb/Zr ratio which are characteristics of active continental margin. The isotopic signature of plutonic rocks is not exactly like those of mantle- or crustal-derived magma, but these rocks have some features commonly found both in the crustal and mantlic sources so that the enclaves tend to illustrate mantlic composition and the acidic rocks tend to show crustal composition, but the intermediate- mafic rocks are in the range from acidic rocks to enclaves. This result along with field and petrographical studies indicate that magma mixing/magma or mingling processes may play an important role in evolution of the intrusion. The upper mantle magma forming the microgranular enclaves, after emplacement in the crust may lead to partial melting of lower crust and because of magma mixing between crustal and mantlic melts, the mafic to intermediate rocks may form.

Keywords

20.1001.1.10237429.1390.21.81.24.7

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Scientific Quarterly Journal of Geosciences

Effective Processes in Evolution of Kuh-e Dom Plutonism, NE Ardestan, the using of Geochemical and Isotopic Evidence

References

References

Volume 21, Issue 81
December 2011
Pages 191-200

Effective Processes in Evolution of Kuh-e Dom Plutonism, NE Ardestan, the using of Geochemical and Isotopic Evidence

References

References

Volume 21, Issue 81December 2011Pages 191-200

Volume 21, Issue 81
December 2011
Pages 191-200