Van Gölü’nün doğusundaki Otlakbaşı bazaltik volkanizmasının petrolojik ve jeokimyasal evrimi

Van Gölü’nün doğusundaki çarpışma ile ilişkili Otlakbaşı volkanizması farklı açılma çatlaklarındanpüskürerek meydana gelmiştir. Bu çalışmada, Otlakbaşı bazaltik volkanizmasının yeni yaş verisive ana oksit, iz ve nadir toprak element jeokimyasal karakteristikleri incelenmiştir. Ar-Ar yaş verisibu bazaltik volkanizmanın bilinen Kuvaterner yaşının aksine Erken Pliyosende püskürdüğüneişaret eder. Volkanik ürünleri alkali-subalkali ayrım çizgisine yakın ve bazaltik bileşimdedirler.Fraksiyonel kristallenme ile birleşik kıtasal kirlenme (AFC) modellerinin sonuçları, magmaodası evrim süreçlerinde fraksiyonel kristallenmenin kıtasal kirlenmeye göre ihmal edilebilirolduğuna ve kıtasal kirlenmenin fraksiyonel krsitallemeye oranının (r değeri) 0.1 ile 0.35 arasındadeğiştiğine işaret eder. Büyük iyon yarıçaplı litofi l elementlerin ve (BİYL) hafif nadir toprakelementlerin (HNTE) yüksek alan şiddetli elementlere (YAŞE) göre zenginleşmesi ve hareketliiz elementlerin (Ba, Th) davranışı, Otlakbaşı bazaltik volkanizmasının manto kaynak bölgesinindalmış sedimentlerden türeyen ergiyikler ile zenginleştiğini ortaya koymuştur. Fraksiyonlanmadoğrulaması yapılan örneklerin Rb ve K elementlerindeki tüketilme, manto kaynak alanında fl ogopitve/veya amfi bolün var olabileceğine işaret eder. Kısmi ergime modelleme çalışmalarının sonuçları,bu bazaltik volkanizmanın baskın olarak spinel peridotit kaynağının ergimesi ile üretilebileceğinigöstermiştir. Metasomatize olmuş spinelce zengin litosferik mantonun ergimesi, Otlakbaşı bazaltikvolkanizmasının püskürmesinden sorumlu olabilir.

Geochemical and petrologic evolution of Otlakbaşı basaltic volcanism to the east of Lake Van

Collision-related Otlakbaşı volcanism to the east of Lake Van occurred by eruptions from extensional fi ssures. In this study, it is investigated new Ar-Ar age data and major, trace and rare earth elements characteristics of the Otlakbaşı basaltic volcanism. The Ar-Ar age data indicate that this basaltic volcanism erupted in Early Pliocene time in contrast to its previously known as Quaternary age. The volcanic products are basaltic composition and close to alkaline-subalkaline division line. Results of fractional crystallization accompanied by assimilation (AFC) modelling imply that fractional crystallisation can be negligible compared to crustal contamination in the evolution processes of the magma chamber and ratio of the crustal contamination to the fractional crystallisation (r values) varies from 0.1 to 0.35. Enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to high strength fi eld elements (HFSE) and behaviour of mobile elements (Ba and Th) reveal that the mantle source region of the Otlakbaşı basaltic volcanism might have been enriched by melts that were derived from subducted sediments. Depletion in Rb and K elements of the fractionated-corrected samples indicate that amphibole and/or phlogopite could be presence in the mantle source. Results of partial melting model studies show that this basaltic volcanism can be predominantly produced by the melting of the spinel peridotite source. Metasomatized spinel bearing lithospheric mantle may be responsible for the eruption of the Otlakbaşı basaltic volcanism.

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Acarlar, M., Erkal, T., Güner, E., Şen, A., Umut, M., Elibjol, E., Gedik, İ., Hakyemez, Y., Uğuz, F. 1991. Van Gölü Doğu ve Kuzeyinin Jeolojisi, Maden Tetkik ve Arama Genel Müdürlüğü, Rapor No: 9469, 94 s. Ankara (yayınlanmamış).
Adam, J., Green, T. 2006. Trace element partitioning between mica- and amphibole-bearing garnet lherzolite and hydrous basanitic melt: 1. Experimental results and the investigation of controls on partitioning behavior. Contributions to Mineralogy and Petrology 152, 1-17.
Aldanmaz, E., Yalınız, M.K., Güçtekin, A., Göncüoğlu, M.C. 2007. Geochemical characteristics of mafi c lavas from the Neotethyan ophiolites in western Turkey: implications for heterogeneous source contribution during variable stages of ocean crust generation. Geological Magazine 145, 37-54.
Al-Lazki, A., Seber, D., Sandvol, E., Türkelli, N., Mohamad, R., Barazangi, M. 2003. Tomographic Pn velocity and anisotropy structure beneath the Anatolian plateau (eastern Turkey) and the surrounding regions, Geophysical Research Letter 30, 8043.
Allen, M., Armstrong, H. A. 2008. Arabia-Eurasia collision and the forcing of mid-Cenozoic global cooling. Palaeogeography, Palaeoclimatology, Palaeoecology 265, 52-58.
Angus, D.A., Wilson, D.C., Sandvol, E., Ni, J.F. 2006. Lithospheric structure of the Arabian and Eurasian collision zone in Eastern Turkey from S-wave receiver functions. Geophysical Journal of International 166, 1335-1346.
Bağcı, U., Alpaslan, M., Frei, R., Kurt, M.A., Temel, A. 2011. Different Degrees of Partial Melting of the Enriched Mantle Source for Plio-Quaternary Basic Volcanism, Toprakkale (Osmaniye) region, Southern Turkey. Turkish Journal of Earth Science 20, 115-135.
Bravo, M.S., O’Hara, M.J. 1975. Partial melting of phlogopite–bearing synthetic spinel– and garnet– lherzolites. Physics and Chemistry of the Earth 54, 845-854.
Class, C., Miller, D. M., Goldstein, S. L., Langmuir, C. H. 2000. Distinguishing melt and fl uid subduction components in Umnak volcanics: Aleutian arc. Geochemistry, Geophysics, Geosystems (3G) 1, 1-34.
Condamine, P., Medard, E., Devidal, J.L. 2016. Experimental melting of phlogopite-peridotite in the garnet stability fi eld. Contribution to mineralogy and petrology 95, 1-26.
DePaolo, D. J. 1981. Trace element and isotopic effects of combined wall-rock assimilation and fractional crystallization. Earth and Planetary Science Letters 53, 189–202.
EARTHREF (Geochemical Earth Reference). http:/www. earthref.org. 1.12.2017.
Elburg, M. A., Bergen, M. V., Hoogewerff, J., Foden, J., Vroon, P., Zulkarnain, I., Nasution, A. 2002. Geochemical trends across an arc–continent collision zone: magma sources and slab– wedge transfer processes below the Pantar Strait volcanoes, Indonesia. Geochimica et Cosmochimica Acta 66, 2771–2789.
Elliott, T., Planck, T., Zindler, A., White, W., Bourdon, B. 1997. Element transport from slab to volcanic front at the Mariana arc. Journal of Geophysical Research 102, 14991–15019.
Foley, S. F., Tiepolo, M., Vannucci, R. 2002. Growth of early continental crust controlled by melting of amphibolite in subduction zones. Nature 417, 837– 840.
Furham, T., Graham, D. 1999. Erosion of lithospheric mantle beneath the East African Rift system: geochemical evidence from the Kivu volcanic province. Lithos, 48, 237-262.
Green, D. H., Ringwood, A. E. 1967. The stability fi elds of aluminous pyroxene peridotite and garnet peridotite. Earth and Planetary Science Letters 3, 151-160.
Göğüş, O. H., Pysklywec, R. N. 2008. Mantle lithosphere delamination driving plateau uplift and synconvergent extension in eastern Anatolia. Geology 36, 723-726.
Gök, R., Sandvol, E., Türkelli, N., Seber, D., Barazangi, M. 2003. Sn attenuation in the Anatolian and Iranian plateau and surrounding regions, Geophysical Research Letter 30, 8038 -8042.
Hawkesworth, C. J., Turner, S. P., McDermott, F., Peate, D. W., Van Calsteren, P. 1997. U–Th isotopes in arc magmas: implications for element transfer from the subducted crust. Science 276, 551–555.
Hofmann, A.W., Hart, S. 1978. An assessment of local and regional ısotopic equilibrıum in the mantle. Earth and Planetary Science Letters 38, 44-62.
http://www.earthref.org.
Innocenti, F., Mazzuoli, R., Pasquaré, G., Radicati di Brozolo, F., Villari, L. 1982. Tertiary and Quaternary volcanism of the Erzurum-Kars area (Eastern Turkey): Geochronological data and geodynamic evolution. Journal of Volcanology and Geothermal Research 13, 223-240.
Irvine, T. N., Baragar, W. R. A. 1971. A guide to the chemical classifi cation of the common volcanic rocks. Canadian Journal of.Earth Sciences 8, 523-548.
Ionov, D.A., Bodinier, J.-L.,Mukasa, S.B. Zanetti, A. 2002. Mechanisms and sources of mantle metasomatism: major and trace element compositions of peridotite xenoliths from Spitsbergen in the context of numerical modelling. Journal of Petrology 43, 2219–2259.
Karaoğlan, F., Parlak, O., Thöni, M., Klötzli, U., Koller, F. 2016. The temporal evolution of the active margin along the Southeast Anatolian Orogenic Belt (SE Turkey): Evidence from U–Pb, Ar–Ar and fi ssion track chronology. Gondwana Research 33, 190- 208.
Karapetian, S.G., Jrbashian, R.T., Mnatsakanian, A.K. 2001. Late collision rhyolitic volcanism in the northeastern part of the Armenian Highland, Journal of Volcanology and Geothermal Research 112, 189-220.
Keskin, M. 2003. Magma generation by slab steepening and breakoff beneath a subduction-accretion complex: An alternative model for collisionrelated volcanism in Eastern Anatolia, Turkey. Geophysical Research Letters 30, 8046-8050.
Keskin, M. 2007. Eastern Anatolia: a hot spot in a collision zone without a mantle pluma. In:Foulger, G.R., and Jurdy, D., (eds) Plates, Plumes and Planetary Processes. Geological Society of America, Special papers 430, 693-722.
Keskin, M., Chugaev, A., Lebedev, A. V., Sharkov, E. V., Oyan, V., Kavak, O. 2012. The Geochronology and Origin of Mantle Sources for Late Cenozoic Intraplate Volcanism in the Frontal Part of the Arabian Plate in the Karacadağ Neovolcanic Area of Turkey. Part 2. The Results of Geochemical and Isotope (Sr–Nd–Pb) Studies. Journal of Volcanology and Seismology 6, 43-70.
Keskin, M., Genç, Ş. C., Aysal, N., Özeren, M. S., Sharkov, E. V., Lebedev, V. A., Chugaev, A. V., Oyan, V., Özdemir, Y., Ünal, E., Karaoğlu, Ö., Duru, O. 2013. Tectono-magmatic processes across the Arabian-Eurasian collision zone and their geodynamic signifi cance: an integrated geological, petrological, geochemical and geochronological study of the post-collisional Cenozoic volcanic units displaying a transition from orogenic to anorogenic nature across a geotraverse from Caucasus to Arabian foreland, Unpublished report of TÜBİTAK-RFBR project #108Y222.
Keskin, M., Pearce, J. A., Mitchell, J. G. 1998. Volcanostratigraphy and geochemistry of collision-related volcanism on the Erzurum-Kars Plateau, North Eastern Turkey. Journal of Volcanology and Geothermal Research 85, 355-404.
Kessel, R., Schmidt, M., Ulmer, P., Pettke, T. 2005. Trace element signature of subduction-zone fl uids, melts and supercritical liquids at 120-180 km depth. Nature 437, 724-727.
Koçyiğit, A., Yılmaz, A., Adamia, S., Kuloshvili, S. 2001. Neotectonics of East Anatolian plateau (Turkey) and lesser caucasus: Implication for transition from thrusting to strike-slip faulting. Geodinamica Acta 14, 177-195.
Krienitz, M. S., Haase, K.M., Mezger, K., Eckardt, V., Shaikh-Mashail, M. A. 2006. Magma genesis and crustal contamination of continental intraplate lavas in northwestern Syria. Contribution of Mineralogy and Petrology 151, 698–716.
Le Bas, M.J., Le Maitre, R.W., Streckeisen, A., Zanettin, B. 1986. A chemical classifi cation of volcanic rocks based on the total alkali-silica diagram. Journal of Petrology 27, 745–750.
Lebedev, V.A., Sharkov, E.V., Keskin, M., Oyan, V. 2010. Geochronology of the Late Cenozoic volcanism in the area of Van Lake (Turkey): an example of the developmental dynamics for magmatic processes. Doklady Earth Sciences 433, 1031–1037.
Lustrino, M., Wilson, M. 2007. The circum-Mediterranean anorogenic Cenozoic igneous province. Earth Science Reviews 81, 1-65.
Mc Kenzie, D. P., O’Nions, R. K. 1991. Partial melt distributions from inversion of rare earth element concentrations. Journal of Petrology 32, 1021- 1091.
MTA. 2008. 1/100000 ölçekli Başkale K-51 paftası. Maden Tetkik ve Arama Genel Müdürlüğü, Ankara.
Okay, A. I., Zattin, M., Cavazza, W. 2010. Apatite fi ssiontrack data for the Miocene Arabian-Eurasia collision. Geology 38, 35-38.
Oyan, V. 2011. Vocanostratigraphy, Petrology and Magmatic Evolution of the Etrusk Volcano and Surrounding Areas (North of Lake Van, Turkey). PhD thesis, Yüzüncü Yıl Universtiy, 362 s.Van, Turkey.
Oyan, V., Keskin, M., Lebedev, V.A., Chugaev, A.V., Sharkov, E.V. 2016. Magmatic evolution of the Early Pliocene Etrüsk stratovolcano, Eastern Anatolia collision zone, Turkey. Lithos 256-257, 88-108.
Oyan, V., Keskin, M., Lebedev, V.A., Chugaev, A.V., Sharkov, E.V., Ünal, E. 2017. Petrology and Geochemistry of the Quaternary Mafi c Volcanism in the northeast of Lake Van, Eastern Anatolian Collision Zone, Turkey. Journal of Petrology DOI: https://doi.org/10.1093/petrology/egx070.
Özacar, A.A., Gilbert, H., Zandt, G. 2008. Upper mantle discontinuity structure beneath East Anatolian Plateau (Turkey) from receiver functions. Earth and Planetary Science Letters 269, 426-434.
Özdemir, Y., Karaoğlu, Ö., Tolluoğlu, A.Ü., Güleç, N. 2006. Volcanostratigraphy and petrogenesis of the Nemrut stratovolcano (East Anatolia High Plateau): The most recent post-collisional volcanism in Turkey. Chemical Geology 226, 189-211.
Özdemir, Y., Güleç, N. 2014. Geological and Geochemical evoluation of Suphan Stratovolcano Eastern Anatolia, Turkey: Evidence for the lithosphereasthenosphere interaction on post collisional volcanism. Journal of Petrology 55, 37-62.
Parlak, O., Delaloye, M., Kozlu, H., Fontıgnie, D. 2000. Trace element and Sr-Nd isotope geochemistry of the alkali basalts observed along the Yumurtalık Fault (Adana) in southern Turkey. Yerbilimleri 22, 137-148.
Pearce, J.A., Bender, J.F., De Long, S.E., Kidd, W.S.F., Low, P.J., Güner, Y., Şaroğlu, F., Yılmaz, Y., Moorbath, S., Mitchell, J.G. 1990. Genesis of collision volcanism in Eastern Anatolia, Turkey. Journal of Volcanol and Geothermal Research 44, 189-229.
Pearce, J.A., Stern.R.J., Bloomer, H.S., Fryer, P. 2005. Geochemical mapping of the Mariana arc-basin system: Implications for the nature and distribution of subduction components. Geochemistry, Geophysics, Geosystem (3G) 6, 1-27.
Peccerillo, A., Taylor, S.R. 1976. Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area. Northern Turkey. Contributions to Mineralogy and Petrology 58 63–81.
Plank, T., Langmuir, C. H. 1998. The chemical composition of subducting sediment and its consequences for the crust and mantle. Chemical Geology 145, 325–394.
Sandvol, E., Türkelli, N., Barazangi, M. 2003. The Eastern Turkey Seismic Experiment: The study of a young continent-continent collision. Geophysical Research Letter 24, 8038-8041.
Schildgen, T.F., Yildirim, C., Cosentino, D., Strecker, M.R. 2014. Linking slab break-off, Hellenic trench retreat, and uplift of the central and Eastern Anatolian plateaus. Earth Science Reviews 128, 147–168.
Shaw, D.M. 1970. Trace element fractionation during anatexis. Geochimica et Cosmochimica Acta 34, 237-243.
Shaw, J.E., Baker, J.A., Menzies, M.A., Thirlwall, M.F., İbrahim, K.M. 2003. Petrogenesis of the largest intraplate volcanic fi eld on the Arabian Plate (Jordan): a mixed lithosphere–asthenosphere source activated by lithospheric extension. Journal of Petrology 44, 1657– 1679.
Staudacher,Th., Jessberger, E. K., Dorfl inger, D., Kiko, J. 1978. A refi ned ultra-high vacuum furnace for rare gas analysis. Journal of Physics E: Scientifi c Instruments 11,781-784.
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. (ed.) In Magmatism in Ocean Basins, Geological Society of London Special Publication 42, 313-345.
Şengör, A.M.C., Kidd, W.S.F. 1979. Post – collisional tectonics of the Turkısh – Iranian plateau and a comparison with tibet. Tectonophysisics 55, 361- 376.
Şengör, A.M.C., Özeren, M.S., Keskin, M., Sakınç, M., Özbakır, A.D., Kayan, I. 2008. Eastern Turkish high plateau as a small Turkic-type orogen: implications for post-collisional crust-forming processes in Turkic-type orogens. Earth Science Reviews 90, 1-48.
Takahashi, E., Kushiro, I. 1983. Melting of a dry peridotite at high pressures and basalt magma genesis. American Mineralogist 68, 859-879.
Tatsumi, Y., Hamilton, D.J., Nesbitt, R. W. 1986. Chemical characterization of fl uid phase released from a subducted lithosphere and origin of arc magmas: Evidence from high-pressure experiments and natural rocks. Journal of Volcanology and Geothermal Research 29, 293–309.
Taylor, S.R., McLennan, S.M. 1985. The continental crust: its composition and evolution, Geoscience Texts. Blackwell Scientifi c Publications, London.
Topuz, G., Altherr, R., Kalt, A., Satır, M., Werner, O., Schwarz, W.H. 2004. Aluminous granulites from the Pulur complex, NE Turkey: a case of partial melting, effi cient melt extraction and crystallization, Lithos 72, 183-207.
Turner, S. P. 2002. On the time-scales of magmatism at island-arc volcanoes. Philosophical Transactions of the Royal Society of London, Mathematical, Physical and Engineering Sciences 360, 2853– 2871.
Yılmaz, Y., Şaroğlu, F., Güner, Y. 1987. Initation of the neomagmatism in East Anatolia. Tectonophysics 137, 177-199.
Yılmaz, Y., Güner, Y., Şaroğlu, F. 1998. Geology of the Quaternary volcanic centres of the East Anatolia. Journal of Volcanology and Geothermal Research 85,173-210.
Zor, E., Gürbüz, C., Türkelli, N., Sandvol, E., Seber, D., Barazangi, M. 2003. The crustal structure of the East Anatolian Plateau from receiver functions. Geophysical Research Letters 30, 8044-8047.