Document Type : Original Research Paper


1 Assistant Professor, Research Institute for Earth Science, Geological Survey of Iran, Tehran, Iran.

2 M.Sc., Geological Survey of Iran, Tehran, Iran

3 Associate Professor, Department of Geology, Faculty of Science, Islamic Azad University- Science and Research Branch, Tehran, Iran.


Oshnavieh Plutonic Complex (OPC), hosted within the northernmost part of the Sanandaj- Sirjan zone, allows distinguishing three suites including diorite, granite and alkalisyenite-alkaligranite (AS-AG). Dioritic rocks formed from partial melting of enriched lithospheric mantle sources on base of minerlogical and geochemistry. The granite suite is S type that formed from partial melting of metapelitic-greywacke source. The peraluminous A-type granite of AS-AG suite are generated by partial melting of quartzo-feldspatic source at high temperatures. According to the negative Nb, Ta and Ti anomaly in spider diagrams, and tectonic discrimination diagram of Rb-(Y+Nb), the diorite suite formed in active continental margin (VAG) environment. According to the diorite’s formed environment and simultaneously formed granite in 100 M.a., OPC seems to have formed by northeastward subduction of Neo-tethyan oceanic crust under the Iranian continental crust. Following intrusion and setting of mafic magma into the crust, partial melting of pelitic-greywacke, resulted from heating by intrusion of the mafic magma, produced the granitic magma. After 20 Ma the AS-AG suite formed from melting of quartzo-feldspatic rocks of lower crust, probably by heating of mafic magma and/or in relaxation period of subduction and emplaced in the continental volcanic arc.


Alavi, M., 1994- Tectonic of the Zagros orogenic belt of Iran: new data and interpretations. Tectonophysics 229, 211-238.
Altherr, R., Holl, A., Hegner, E., Langer, C. & Kreuzer, H., 2000- High-potassium, cala-alkaline I-type plutonism in the European Variscides: northern Vosges (France) and northern Schwarzwald (Germany). Lithos 50, 51-73.
Anderson, J. L., 1983- Proterozoic anorogenic granite plutonism of North America. Geological Society of American Memory 161, 133-154.
Bedard, J., 1990- Enclaves from the A-type granite of the Megantic complex, White Mountain magma series: clues to granite mag-magenesis. Journal of Geophysical Research 95(B11), 17797-17819.
Berberian, M. & King, G. C. P., 1981- Toward a paleogeography and tectonic evolution of Iran. Canadin Journal of Earth Scince, 18, 210-265.
Blundy, J. D. & Holland, T. J. B., 1990- Calcic amphibole equilibria and a new amphibole-plagioclase geothermometer. Contributions to mineralogy and petrology 104, 208-224.
Boynton, W. V., 1984- Cosmochemistry of the rare earth elements: meteorite studies. In: Henderson, P., (Ed.), Rare Earth Element Geochemistry, Elsevier, Amsterdam, 63-114.
Chappell, B. W. & White, A. J. R., 1974- Two contrasting granite types. Pacific Geology 8, 173-174.
Chappell, B. W. & White, A. J. R., 1992- I- and S-type granites in Lachlan fold belt. Transactions of Royal Society Edinburgh Earth Sciences 83, 1-26.
Chappell, B. W., Bryant, C. J., Wyborn, D. & White, A. J. R., 1998- High- and Low-Temperature I-type granites. Resource Geology 48, 225-235. 
Clemens, J. D., Holloway, J. R. & White, A. R. J., 1986- Origin of an A-type granite: experimental constraints. American Mineralogist 71, 317-324.
Collins, W. J., Beams, S. D., White, A. J. R. & Chappell, B. W., 1982- Nature and origin of A-type granite with particular reference to south eastern Australia. Contributions to mineralogy and petrology 80, 189-200.
Creaser, R. A., Price, R. C. & Wormald, R. J., 1991- A-type granite revisited: assessment of a residual-source modal. Geology 19, 163-166.
Deer, W. A., Howie, R. A. & Zussman, J., 1992- An introduction to the rock forming  minerals.  John Wiley & Sons, Inc. New York, 2nd ed. pp 696.
Forst, C. D. & Forst, R. B., 1997- Reduced rapakivi-type granites: the tholeiite connection. Geology 25, 647-650.
Forster, H. J., Tischendorf, G. & Trumbull, R. B., 1997- An evaluation of the Rb vs. (Y+Nb) discrimination diagram to infer tectonic setting of silicic igneous rocks. Lithos, 40, 261-293.
Hammarstrom, J. M. & Zen, E. A., 1986- Aluminum in hornblende: An empirical igneous geobarometer. American Mineralogist 71, 1297-1313.
Harker, A., 1909- The natural history of igneous rocks. Methuen and Co., London, 344 pp.
Harris, N. B. W., Hawkesworth, C. J. & Ries, A., 1984- Crustal evolution in north-east and east Africa from model Nd ages. Nature 309, 773-776.
Johnson, M. C. & Rutherford, M. J., 1989- Experimental calibration of an aluminum-in-hornblende geobarometer with application to Long Valley caldera (California) volcanic rocks. Geology 17, 837-841.
Jung, S., Hoernes, S.  & Mezger, K., 2000- Geochronology and petrogenesis of Pan- African, syn-tectonic, S-type and post-tectonic A-type granite (Namibia): products of melting of crustal source, fractional crystallization and wall rock entrainment. Lithos 50, 259–287.
King, P. L., White, A. J. R., Chappell, B. W. &  Allen, C. M., 1997- Characterization and origin of aluminous A-type granite from the Lachlan fold belt, Southeastern Australia. Journal of petrology 38, 371-391.
King, P. L., Chappell, B. W., Allen, C. M. & White, A. J. R., 2001- Are A-type granites the high-temprature felsic granites? Evidence from fractionated granites of the Wangrah suite. Australian Journal of earth science 48, 501-514.
Leake, B. E., Wooley, A. R., Birch, W. D., Burke, E. A. J., Ferraris, G., Grice, J. D., Hawthorne, F. C., Kisch, H. J., Krivovichev, V. G., Schumacher, J. C., Stephenson, N. C. N. & Whittaker, E. J. W., 1997- Nomenclature of the amphiboles: report of the subcomittee on the amphiboles of the International Mineralogical Association. Canadian Mineralogist 35, 219–246.
Loiselle, M. C. & Wones, D. R., 1979- Characteristics and origin of anorogenic granites. Geological Society of America Abstracts 11(7), 468.
Maniar, P. D. & Piccoli, P. M., 1989- Tectonic discrimination of granitoids. Geological Society of America Bulletan 101, 635-643.
Miller, C. F., 1985- Are strongly peraluminous magmas derived from pelitic sedimentary sources? Journal of Geology 93, 673-689.
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.
Mohajjel, M., 1997- Structure and tectonic evolution of Palaeozoic-Mesozoic rocks, Sanandaj-Sirjan Zone, western Iran. Ph.D. thesis, University of Wollongong, Wollongong, Australia (unpublished).
Morimoto, N., 1988- Nomenclature of Pyroxenes. Bull. Mineral. 111, 535-550.
Patino Douce, A. E., 1997- Generation of metaluminous A-type granites by low-pressure melting of calc-alkaline granitoids. Geology 25, 743-746.
Pearce, J. A. & Peate, D. W., 1995- Tectonic implications of the composion of volcanic arc magmas. Annual Review of Earth and Planetary Science 23, 251-285.
Pearce, J. A., Harris, N. B. W. & Tindle, A. G., 1984- Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology 25, 956-983.
Pearce, J., 1996 - Source and setting of granitic rocks, Episode 19, 120-125.
Pitcher, W. S., 1993- The nature and origin of granite. Chapman & Hall, London 321pp.
Ramo, O. T. & Haapala, I., 1991- The rapakivi granites of easthern Fennoseandia: a review withinsights into their origin in the light of new Sm-Nd isotopic data. In: Gower, C.F., River, T. and Ryan, B. (Eds), Mid-Proterozoic Laurentia-Baltica. Geological Association of Canada Special Paper 38, 401-415. 
Rapp, R. P. & Watson, E. B., 1995- Dehydration melting of metabasalt at 8-32 kbar: implications for continental growth and crust-mantle recycling. Journal of Petrology 36, 891-931.
Rapp, R. P., 1995- Amphibole-out phase boundary in partially melted metabasalt, its control over liquid fraction and composition, and source permeability. Journal of Geophysical Research 100, 15601-15610.
Sengor, A. M. C., 1990- A new model for the late Palaeozoic-Mesozoic tectonic evolution of Iran and implication for Oman, Geological Society, London, Special Pulication 49, 797-831.
Stoklin, J., 1968- Structural history and tectonics of Iran: A review. The American Association of Petroleum Geologist Bulletin 52, 1229-1258.
Streckeisen, A., 1976- To each plutonic rocks its proper name. Earth Science Review 12, 1-33.
Sun, S. S. & McDonough, W. F., 1989- Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders, A.D., Norry, M.J. (Eds.), Magmatism in Ocean Basins. Geological Society of London, pp. 313–345 (Special Publication 42).
Vielzeuf, D. & Montel, M. J., 1994- Partial melting of metagreywackes. Part 1, Fluid-absent experiments and phase relationships, Contributions to Mineralogy and Petrology 117, 375-393.
Vyhnal, C. R., Mcsween, H. Y. Jr. & Speer, A., 1991- Hornblende chemistry in southern Appalachian granitoids: implication for aluminium hornblende thermobarometry and magmatic epidote stability. American Mineralogist 76, 176-188.
Watson, E. B. & Harrison, T. M., 1983- Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types. Earth and Planetary Science Letters 64, 295-304.
Whalen, J. B., Currie, K. L.&  Chappell, B. W., 1987- A-type granites: geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology 95, 407-419.
Wilson, M., 1989- Igneous petrogenesis, Unwin Hyman Ltd., 466 pp.