The enigma of inherited Zircon crystals in Qalaylan plutone, Clues from the Gondwana crust in the rocks with primitive isotopic signatures

Abstract

The Qalaylan pluton of Late Jurassic age is composed of intermediate and felsic rocks that crop out in the northern Sanandaj-Sirjan Zone. A body is comprising alkaline, high K, Ferroan A1-type rocks with contrasting aspects; whiles, Nd-Sr primitive isotopic composition consistent with a mantle source. On the other hand, inherited zircon cores (with a range of 230 – 2700 Ma) and elevated Nd model ages (Avg. »670 Ma) indicate that the source of these rocks was not juvenile mantle-derived subduction related magma. Unusually large proportion of inherited zircons demonstrates that fast and non-equilibrium melting of pre-fertile crust with primitive isotopic signatures was the source of these rocks. Zoning and porphyritic texture of the body, oscillatory zoning of plagioclase grains and unusually amount of pre-magmatic zircons all are evidences of non-equilibrium condition as a result of fast cooling rate of parental magma of Qalaylan.

Keywords


[1] Molnar M., "Tertiary Development of the Zagros Mountains", Geol.186 -earth history (2006).

[2] Mouthereau F., Lacombe O., Vergés J., "Building the Zagros collisional orogen: Timing, strain distribution and the dynamics of Arabia/Eurasia plate convergence", Tectonophysics 532–535 (2012) 27-60.

[3] Berberian F., Berberian M., "Tectono-plutonic episodes in Iran. In: Gupta, H.K., Delany, F.M., (Eds.), Zagros, Hindukush, Himalaya geodynamic evolution", American Geophysical :union: Geodynamic Series 3 (1981) 5–33.

[4] Agard P., Omrani J., Joliver L., Mouthereau F., "Convergence history across Zagros (Iran): constraints from collisional and earlier deformation", International Journal of Earth Sciences 94 (2005) 401–419.

[5] Agard P., Omrani J., Jolivet L., Whitechurch H., Vrielynck B., Spakman W., Monie P., Meyer B., Wortel R., "Zagros Orogeny: a subduction-dominated process", Geological Magazine 148 (2011) 692-725.

[6] Mohajjel M., Fergusson C.L., Sahandi M.R., "Cretaceous–Tertiary convergence and continental collision, Sanandaj–Sirjan Zone, Western Iran", Journal of Asian Earth Sciences 21 (2003) 397-412.

[7] Mohajjel M., Fergusson C.L., "rassic to Cenozoic tectonics of the Zagros Orogen in northwesternIran", International Geology Review, 56)3) (2014)263-287.

[8] Hassanzadeh J., Stockli D. F., Horton B. K., Axen G. J., Stockli L. D., Grove M., Schmitt A. K., Walker J. D., "U-Pb zircon geochronology of late Neoproterozoic–Early Cambrian granitoids in Iran: Implications for paleogeography, magmatism, and exhumation history of Iranian basement", Tectonophysics 451 (2008) 71-96

[9] Horton B.K., Hassanzadeh J., Stockli D.F., Axen G.J., Gillis R. J., Guest B., Amini A., Fakhari M.D., Zamanzadeh S.M., Grove M., "Detrital zircon provenance of Neoproterozoic to Cenozoic deposits in Iran: Implications for chronostratigraphy and collisional tectonics" Tectonophysics 451 (2008) 97–122.

[10] Stöcklin J., "Possible Ancient Continental Margins in Iran. In: Burk, C.A. and Drake, C.L. (eds.).", The Geology of Continental Margins, New York, Springer-Verlag (1974) 873-887.

[11] Azizi H., Zanjefili Beiranvand M., Asahara Y., "Zircon U–Pb ages and petrogenesis of a tonalite–trondhjemite–granodiorite (TTG) complex in the northern Sanandaj–Sirjan Zone, northwest Iran: Evidence for Late Jurassic arc–continent collision", Lithos 216 (2014) 178-195.

[12] Montero P., Bea F., "Accurate determination of 87Rb/86Sr and 147Sm/144Nd ratios by inductively-coupled-plasma mass spectrometry in isotope geoscience: an alternative to isotope dilution analysis", Analytica Chimica Acta, 358 (1998) 227–233.

] 13[ حسینی اختیار آبادی م.، و همکاران،. "نقشه زمین شناسی 100000/1 قروه"، سازمان زمین شناسی و اکتشافات معدنی کشور، ١٣٧٦.

] 14[ اشراقی ص.ع.، همکاران، "نقشه زمین شناسی 100000/1 سنقر"، سازمان زمین‌شناسی و اکتشافات معدنی کشور، 1375.

[15] Frost B.R., Barnes C.G., Collins W.J., Arculus R.J., Ellis D.J., Frost C.D., "A geochemical classification for granitic rocks", Journal of Petrology, 42 (2001) 2033–2048.

[16] Hofmann A.W.," Chemical differentiation of the Earth: the relationship between mantle, continental crust, and oceanic crust", Earth and Planetary Science Letters, 90 (1988) 297-314.

[17] McDonough W.F., Sun S.-S.," Composition of the Earth", Chemical Geology 120 (1995) 223–253.

[18] DePaolo D.J.,"Neodymium isotopes in the Colorado Front Range and implications for crust formation and Mantle evolution in the Proterozoi" Nature 291 (1981) 193-197.

[19] Yajam S., Montero P., Scarrow J., Ghalamghash J., Razavi S.M.H., Bea F., "The spatial and compositional evolution of the Late Jurassic Ghorveh-Dehgolan plutons of the Zagros Orogen, Iran: SHRIMP zircon U-Pb and Sr and Nd isotope evidence", Geologica Acta 13(1) (2015) 25-43.

[20] Eby G.N.," Chemical subdivision of A-type granitoids: petrogenetic and tectonic implications", Geology 20 (1992) 641–644.

[21] Moreno J. A., Molina J. F., Montero P., Abu Anbar M., Scarrow J. H., Cambeses A., Bea F., "Unraveling sources of A-type magmas in juvenile continental crust: Constraints from compositionally diverse Ediacaran post-collisional granitoids in the Katerina Ring Complex, southern Sinai, Egypt." Lithos 192-195 (2014) 56-85.

[22] Chiu H.-Y., Chung S.-L., Zarrinkoub M.H., Mohammadi S.S., Khatib M.M., Iizuka Y., "Zircon U–Pb age constraints from Iran on the magmatic evolution related to Neotethyan subduction and Zagros orogeny", Lithos 162-163 (2013) 70-87.

[23] Esna-Ashari A., Tiepolo M., Valizadeh M. V., Hassanzadeh J., Sepahi A.A, "Geochemistry and zircon U–Pb geochronology of Aligoodarz granitoid complex, Sanandaj-Sirjan Zone", Iran. Journal of Asian Earth Sciences 43 (2012) 11–22.

[24] Clemens J.D., Holloway J.R., White A.J.R., "Origin of an Atype granite: experimental constraints", American Mineralogist 71 (1986) 317–324.

[25] Montero P., Bea F., Zinger T. F., Scarrow J. H., Molina J. F., Whitehouse M. J.," 55 million years of continuous anatexis in central Iberia: single zircon dating of the Pen‹a Negra Complex", Journal of the Geological Society, London 161 (2004) 255-264.

[26] Gilotti J. A., McClelland W. C., "Leucogranites and the time of extension in the East Greenland Caledonides", Journal of Geology, 113) 2005) 399-417.

[27] Miller C. F., McDowell S. M., Mapes R.W., "Hot and cold granites? Implications of zircon saturation temperatures and preservation of inheritance", Geology 31 (2003) 529-532.

[28] Bea F., Montero P., Gonzalez-Lodeiro F., Talavera C., "Zircon Inheritance Reveals Exceptionally Fast Crustal Magma Generation Processes in Central Iberia during the Cambro-Ordovician", Journal of petrology 48 (2007) 2327-2339.

[29] Holland T., Blundy J., " Non ideal interactions in calcic amphiboles and their bearing on amphibole – plagioclase thermometery", Contributions to mineralogy and petrology 116 (1994) 433-447.







[30] Watson E.B., Harrison T.M., "Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types", Earth and Planetary Science Letters 64 (1983) 295–304.

[31] Boehnke P., Watson B., Trail D., Harrison T.M., Schmitt A.K., "Zircon saturation re-revisited", Chemical Geology 351 (2013) 324 -334.

[32] Watson E. B., "Dissolution, growth and survival of zircons during crustal fusion: Kinetic principles, geological models and implications for isotopic inheritance", Transactions of the Royal Society of Edinburgh: Earth Sciences 87 (1996) 43-56

[33] Bea F., "Controls on the trace element composition of crustal melts", Transaction of the Royal Society of Edinburg, Earth Sciences 87 (1996) 33–42.

[34] Huppert H. E., Sparks S. J., "The generation of granitic magmas by intrusion of basalt into continental crust", Journal of Petrology 29 (1989) 599-624.