Trachyandesites, trachytes, andesites, and pyrocalstic rocks, with shoshonitic signature, are the main Quaternary volcanic rocks in the Sabalan region (Ardabil). Plagiocalse, K-feldspar, biotite associated with clinopyroxene, and glass are the main constituents of these lavas. Plagioclases are andesine to labradorite while clinopyroxenes have augitic composition. The Sabalan volcanic rocks show enrichment in LREEs (relative to HREEs) and are characterized by enrichment in LILEs and depletion in HFSEs. Petrological observations, along with rare earth and trace elements geochemistry, suggest shoshonitic signature for Sabalan lavas. This signature highlights derivation from a subduction-related source. The Sabalan volcanic rocks are isotopically characterized by derivation from an enriched mantle source with a tendency to plot in the fields defined by island-arc basalts (IAB) and OIBs (in εNd versus 87Sr/86Sr diagram). The geochemical and isotopic characteristics of the Sabalan lavas suggest that their magma has been issued via low degree partial melting of a subduction-metasomatized continental lithospheric mantle. The formation of these lavas is related to slab steepening and breakoff in a postcollisional regime. 1. Introduction Cenozoic magmatism is well known from the peri-Arabic region, north of the Bitlis-Zagros Suture Zone (Figure 1), and ranges in age from Eocene to Plio-Quaternary. The timing of the eruptions and pooling the plutons mostly coincides with and postdates a series of continental collisional events in the northern Bitlis-Zagros Suture Zone region [1, 2]. The Eocene magmatism in the peri-Arabic region (both in the Urumieh-Dokhtar magmatic belt and south of the Anatolian block) is calc-alkalic to shoshonitic, which resulted from subduction of the Neotethyan Ocean beneath the central Iranian and Anatolian blocks. The Plio-Quaternary (and Quaternary) alkaline-ultrapotassic magmatism occupies most of the Turkish-Iranian high plateau (NW Iran and NE Turkey) and is mostly characterized by within-plate and/or subduction-related geochemical characteristics [3–5]. The geochemical variations of late Cenozoic lavas indicate a progression from calc-alkaline to alkaline compositions with time [2]. Figure 1: Simplified tectonic map of the eastern Mediterranean-Persian Gulf region showing the active plate boundaries and post-collisional volcanic rocks in the Peri-Arabian region modified after [ 6]. Abbreviation: PSF = Pampak-Sevan Fault; EKP = Erzurum-Kars Plateau; EAF = East Anatolian Fault; IAESZ = Izmir-Ankara-Erzincan Suture Zone; EF = Ecemis
References
[1]
Y. Dilek and D. L. Whitney, “Cenozoic crustal evolution in central Anatolia: extension, magmatism and landscape development,” in Proceedings of the 3rd International Conference on the Geology of the Eastern Mediterranean, pp. 183–192, 2000.
[2]
Y. Dilek, N. Imamverdiyev, and ？. Altunkaynak, “Geochemistry and tectonics of Cenozoic volcanism in the Lesser Caucasus (Azerbaijan) and the peri-Arabian region: collision-induced mantle dynamics and its magmatic fingerprint,” International Geology Review, vol. 52, no. 4-6, pp. 536–578, 2010.
[3]
J. A. Pearce, J. F. Bender, S. E. De Long et al., “Genesis of collision volcanism in Eastern Anatolia, Turkey,” Journal of Volcanology and Geothermal Research, vol. 44, no. 1-2, pp. 189–229, 1990.
[4]
M. Keskin, “Magma generation by slab steepening and breakoff beneath a subduction-accretion complex: an alternative model for collision-related volcanism in Eastern Anatolia, Turkey,” Geophysical Research Letters, vol. 30, no. 24, pp. 1–9, 2003.
[5]
M. Kheirkhah, M. B. Allen, and M. Emami, “Quaternary syn-collision magmatism from the Iran/Turkey borderlands,” Journal of Volcanology and Geothermal Research, vol. 182, no. 1-2, pp. 1–12, 2009.
[6]
Y. Dilek and ？. Altunkaynak, “Geochemical and temporal evolution of Cenozoic magmatism in Western Turkey: mantle response to collision, slab break-off, and lithospheric tearing in an orogenic belt,” Geological Society of London Special Publication, vol. 311, pp. 213–233, 2009.
[7]
R. Riou, C. Dupuy, and J. Dostal, “Geochemistry of coexisting alkaline and calc-alkaline volcanic rocks from northern Azerbaijan (N.W. Iran),” Journal of Volcanology and Geothermal Research, vol. 11, no. 2-4, pp. 253–275, 1981.
[8]
D. Dhont and J. Chorowicz, “Review of the neotectonics of the Eastern Turkish-Armenian Plateau by geomorphic analysis of digital elevation model imagery,” International Journal of Earth Sciences, vol. 95, no. 1, pp. 34–49, 2006.
[9]
Y. ？zdemir, ？. Karao？lu, A. ü. Tolluo？lu, and N. Güle？, “Volcanostratigraphy and petrogenesis of the Nemrut stratovolcano (East Anatolian High Plateau): the most recent post-collisional volcanism in Turkey,” Chemical Geology, vol. 226, no. 3-4, pp. 189–211, 2006.
[10]
H. E. ？ubuk？u, I. Ulusoy, E. Aydar et al., “Mt. Nemrut volcano (Eastern Turkey): temporal petrological evolution,” Journal of Volcanology and Geothermal Research, vol. 209-210, pp. 33–60, 2012.
[11]
F. Innocenti, R. Mazzuoli, G. Pasquarè, F. Radicati Di Brozolo, and L. Villari, “Tertiary and quaternary volcanism of the Erzurumkars area (Eastern Turkey): geochronological data and geodynamic evolution,” Journal of Volcanology and Geothermal Research, vol. 13, no. 3-4, pp. 223–240, 1982.
[12]
P. Comin-Chiaramonti, S. Meriani, R. Mosca, and S. Sinigoi, “On the occurrence of analcime in the northeastern Azerbaijan volcanics (northwestern Iran),” Lithos, vol. 12, no. 3, pp. 187–198, 1979.
[13]
M. Aghazadeh, A. Castro, Z. Badrzadeh, and K. Vogt, “Post-collisional polycyclic plutonism from the Zagros hinterland: the Shaivar Dagh plutonic complex, Alborz belt, Iran,” Geological Magazine, vol. 148, no. 5-6, pp. 980–1008, 2011.
[14]
A. Alberti, P. Comin-Chiaramonti, G. Di Battistini, R. Fioriti, and S. Sinigei, “Crystal fractionation in the eastern Azerbaijan (Iran) lower tertiary shoshonitic suite,” Neues Jahrbuch für Mineralogie, Monatshefte, vol. 1, pp. 35–48, 1981.
[15]
J. Dostal and M. Zerbi, “Geochemistry of the Savalan volcano (northwestern Iran),” Chemical Geology, vol. 22, no. C, pp. 31–42, 1978.
[16]
J. Didon and Y. M. Germain, Le Sabalan, Volcan Plio-Quaternaire de l Azerbaidjan oriental (Iran): Etude geologique et petrographique de le difice et de son environment regional [Ph.D. thesis], Docteur du 3 eme cycle. Université de Grenoble, Grenoble, France, 1976.
[17]
J. Leterrier, R. Maury, P. Thonon, D. Girard, and M. Marchal, “Clinopyroxene composition as a method of identification of the magmatic affinities of paleo-volcanic series,” Earth and Planetary Science Letters, vol. 59, no. 1, pp. 139–154, 1982.
[18]
M. J. L. Bas, R. W. L. Maitre, A. Streckeisen, and B. Zanettin, “A chemical classification of volcanic rocks based on the total alkali-silica diagram,” Journal of Petrology, vol. 27, no. 3, pp. 745–750, 1986.
[19]
A. Peccerillo and S. R. Taylor, “Geochemistry of eocene calc-alkaline volcanic rocks from the Kastamonu area, Northern Turkey,” Contributions to Mineralogy and Petrology, vol. 58, no. 1, pp. 63–81, 1976.
[20]
W. F. McDonough and S.-S. Sun, “The composition of the Earth,” Chemical Geology, vol. 120, no. 3-4, pp. 223–253, 1995.
[21]
H. Azizi, Y. Asahara, B. Mehrabi, and S. L. Chung, “Geochronological and geochemical constraints on the petrogenesis of high-K granite from the Suffi abad area, Sanandaj-Sirjan Zone, NW Iran,” Chemie der Erde—Geochemistry, vol. 71, no. 4, pp. 363–376, 2011.
[22]
O. Karsli, M. Ketenci, I. Uysal et al., “Adakite-like granitoid porphyries in the Eastern Pontides, NE Turkey: potential parental melts and geodynamic implications,” Lithos, vol. 127, no. 1-2, pp. 354–372, 2011.
[23]
C. Zhang, C. Ma, and F. Holtz, “Origin of high-Mg adakitic magmatic enclaves from the Meichuan pluton, southern Dabie orogen (central China): implications for delamination of the lower continental crust and melt-mantle interaction,” Lithos, vol. 119, no. 3-4, pp. 467–484, 2010.
[24]
A. Jahangiri, “Post-collisional Miocene adakitic volcanism in NW Iran: geochemical and geodynamic implications,” Journal of Asian Earth Sciences, vol. 30, no. 3-4, pp. 433–447, 2007.
[25]
J. A. Pearce, “Trace element characteristics of lavas from destructive plate boundaries,” in Andesites, R. S. Thorpe, Ed., pp. 525–548, Wiley, New York, NY, USA, 1982.
[26]
R. Bezard, R. Hébert, C. Wang, J. Dostal, J. Dai, and H. Zhong, “Petrology and geochemistry of the Xiugugabu ophiolitic massif, western Yarlung Zangbo suture zone, Tibet,” Lithos, vol. 125, no. 1-2, pp. 347–367, 2011.
[27]
M. Keskin, J. A. Pearce, P. D. Kempton, and P. Greenwood, “Magma-crust interactions and magma plumbing in a postcollisional setting: geochemical evidence from the Erzurum-Kars volcanic plateau, eastern Turkey,” Geological Society of America Special Paper, no. 409, pp. 475–505, 2006.
[28]
A. M. C. ？eng？r, S. ？zeren, T. Gen？, and E. Zor, “East Anatolian High Plateau as a mantle-supported, north-south shortened domal structure,” Geophysical Research Letters, vol. 30, no. 24, pp. 1–8, 2003.
