Document Type : Original Research Paper


1 Islamic Azad University – Ahar branch, Ahar, Iran.

2 Department of Geology, Faculty of Sciences, University of Tabriz, Tabriz, Iran

3 Department of Geology, Faculty of Sciences, University of Tabriz, Tabriz, Iran.

4 Geological Survey of Iran, Tehran, Iran


The study area as a part of Maku-Tabriz zone is located in about 20 km NE of Khoy, NW Iran. Shah Ashan Dagh granite covers about 60 km2 of the area and emplaced into Permian host rocks and covered by Oligo-Miocene sedimentary rocks (Qom Formation). The Shah Ashan Dagh intrusive rocks composed of gabbro and alkali-feldspar granite. Porphyric and granophyric textures indicate shallow depth emplacement and perthitic texture shows hypersolvous nature of this body. The studied mafic rocks have high LREEs relative to HREEs and they indicate relatively enrichment of LILEs and depletion in HFSEs (exception Hf, Ta, Nb). The studied mafic rocks based on positive Nb and Ta anomalies show similarity to plum type MORB. These rocks are tholeiitic and they have mantle plum enriched source. Shah Ashan Dagh granite characterized with high-K, sub-alkaline, metaluminous to peraluminous and weakly peralkaline nature. They have high content of LILEs, especially Th and Rb, and low content of Eu, Sr, Ta, Nb, Ba, and Ti, implying the granites may have been derived from crustal melts.


Al-Saleh, A. M. & Boyle, A. P., 2001- Neoproterozoic ensialic back-arc spreading in the eastern Arabian Shield: geochemical evidence from the Halaban Ophiolite. Journal of African Earth Science, Vol. 33: No. 1, 1-15.
Boynton, W. V., 1984- Geochemistry of the rare earth elements: meteorite studies. In: Henderson, P. (ed.), Rare earth element geochemistry. Elsevier, pp. 203-213.
Cabanis, B. & Leocolle, M., 1989- Le diagramme La/10-Y/15-Nb/8: un outil pour la discrimination des series volcaniques et la mise en evidence des processus de mélange et/ou de contamination crustale. C. R. Acad. Sci. Paris Sér. II 309: 2023- 2029.
De La Roche, H., Leterrier, J., Grand Claude, P. &  Marchal, M., 1980- A classification of volcanic and plutonic rocks using R1-R2 diagrams and major element analyses – its relationships and current nomenclature. Chemical Geology 29: 183-210.
Eby, G. N., 1992-Chemical Subdivision of the A-type granitoides: Petrogenesis and tectonic implications. Geology, 20: 641-644.
Ghasemi, A. & Talbot, C. J., 2006- A new tectonic scenario for the Sanandaj-Sirjan zone (Iran). Journal of Asian Earth Science 26: 683-693.
Grabowsky Jr, G. J. & Norton, I. O., 1994- Tectonic controls on the stratigraphic architecture and hydrocarbon systems of the Arabia plate. The Middle East Petroleum Geosciences (GEOُ ) 1: 413-430.
Harker, A., 1909- The natural history of igneous rocks. Methuen, London.
Irvine, T. N. &  Baragar, W. R. A., 1971- A guide to the chemical classification of  the common volcanic rocks. Can. J. Earth Sci. 8: 523-548.
Maniar, P. D. & Piccoli, P. M., 1989- Tectonic discrimination of granitoids. Geo. Soc. Am. Bull.  Vol. 101.
Mohajjel, M., Fergusson, C. L. & Sahandi, M. R., 2003- Cretaceous-Tertiary convergence and continental collision, Sanandaj-Sirjan Zone, western Iran. Journal of  Asian Earth Sciences 21: 397-412.
Mohajjel, M. & Fergusson, C. L., 2000- Dextral transpression in late Cretaceous continental collision, Sanandaj-Sirjan zone, western Iran. Journal of Structural Geology 22: 1125-1139.
Nedelec, A., Stephens, W. E. & Fallick, A. E., 1995- The Panafrican stratoid granites of Madagascar: alkaline magmatism in a postcollisional extensional setting. J. Petrol. 36: 1367–1391.
Pearce, J. A. & Norry, M. J., 1979- Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks. Contrib. Mineral Petrol. 69: 33-47.
Pearce, J., 1996-  Source and setting of granitic rocks. Episode 19, 120-125.
Pearce, J. A. & Cann, J. R., 1973- Tectonic setting of basic volcanic rocks determined using trace element analysis. Earth Planetary Science Letters 19: 290-300.
Pearce, J. A., Harris, N. B. W. & Tindle, A. G., 1984- Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Geol. Soc. Spec. Publ. 7: 14-24.
Pitcher, W. S., 1997- The Nature and Origin of Granite, 2nd ed. Chapman & Hall, London, p. 386.
Schandl, E. S. & Gorton, M. P., 2002- Application of high field strength elements to discriminate tectonic settings in VMS environments. Economic Geology97: 629-642.
Stampfli, G. M., Marcoux, J. & Baud, A., 1991- Tethyan margins in space and time. Palaeogeography, Palaeoclimatology, Palaeoecology 87, 373-409.
Streckeisen, A., 1976-To each plutonic rock its proper name. Earth Science Reviews12: 1–33.
Sun, S. S. &  McDonough, W. F., 1989- Chemical and isotopic systematics of ocean basalts:Implication for mantle composition and processes. In: Saunders, A.D., Norry, M.J., (Eds.), Magmatism in Ocean Basins. Geological Society of London, Special publication, No. 42: pp. 313-345.
Whalen, J. B., Currie, K. L. & Chappel, B. W., 1987- A-type granites: geochemical characteristics, discrimination and petrogenesis. Contrib. Mineral. Petrol. 95: 407-419.
Zhao, J. H. & Zhou, M. F., 2007- Geochemistry of Neoproterozoic mafic intrusions in the Panzhihua district (Sichuan Province, SW China); implications for subduction rtelated metamorphism in the upper mantle. Precamrian Res. 152: 27-47.