پترولوژی گدازه های جوان ماکو-پلدشت؛ با نگاهی به توزیع اندازه بلورهای الیوین و حفرات

نوع مقاله : مقاله پژوهشی

نویسنده

گروه زمین شناسی، دانشکده علوم، دانشگاه ارومیه، ارومیه، ایران

چکیده

گدازه های سیاه جوانی به سن کمتر از یک میلیون سال، با منشاء گرفتن از آتشفشان آرارات، دشت وسیع بین ماکو تا پلدشت را در آذربایجان‌غربی با دبی دیاکلازی، آآ و پاهوهو پوشانیده اند. ترکیب این واحد با کانی های پلاژیوکلاز، الیوین‌های شکل دار تا نیمه شکل دار و کمی کلینوپیروکسن، از نوع بازالتی تا آندزی بازالتی بوده و ماهیت کالکوآلکالن دارند. این سنگ ها از نوع بازالت های درون صفحه ای می باشند. فاکتور ∆Nb بیانگر تعلق این بازالت ها به انواع طغیانی درون صفحه قاره ای است. بررسی منحنی توزیع اندازه بلورهای الیوین موجود در این بازالت ها نشان داد که نرخ هسته بندی به رشد برای الیوین ها 4 تا 5 برابر بوده است شیب خط که با نسبت -1/Gt معادل است برای الیوین های بازالت های ماکو از 3- تا 5- بوده که با در نظر داشتن سرعت رشد بلور در شرایط استاندارد، بیانگر توقف 60 تا 90 ساله برای ماگما در لانه زیرین جهت رشد بلورهای الیوین می باشد. با توجه به الگوی BSD برای حفرات بازالت های ماکو معلوم شد که نرخ هسته بندی به رشد حباب ها اغلب معادل بوده یا در برخی موارد نرخ رشد بر وقوع هسته ها تفوق داشته است. نکته مهم اینکه در واحد زمان رشد حباب های گاز 3 تا 5 برابر رشد بلور الیوین بوده است که با ترکیب بازیک گدازه های ماکو چنین حجم گاززدایی قابل پیش بینی است.

کلیدواژه‌ها


Abdel-Rahman, A., El-Kibbi, M., 2001. Anorogenic magmatism: chemical evolution of the Mount El-Sibai A-type complex (Egypt), and implications for the origin of within-plate felsic magmas. Geological Magazine 138(1), 67-85 http://doi:10.1017/S0016756801005052
Ahmadzadeh, G., Jahangiri, A., Lentz, D., Mojtahedi, M., 2010. Petrogenesis of Plio-Quaternary post-collisional ultrapotassic volcanism in NW of Marand, NW Iran. Journal of Asian Earth Sciences 39, 37-50 http://dx.doi.org/10.1016/j.jseaes.2010.02.008
Azad, S.S., Dominguez, S., Philip, H., Hessami, K., Forutan, M.R., Shahpasand Zadeh, M., Ritz, J. F., 2011. The Zanjan fault system: Morphological and tectonic evidences of a new active fault network in the NW of Iran, Tectonophysics 506, 73-85 http:// doi:10.1016/j.tecto.2011.04.012
Barbarin, A., 1999. A review of the relationships between granitoid types, their origins and their geodynamic environments. Lithos 46, 625-646 http://dx.doi.org/10.1016/S0024-4937(98)00085-1
Cashman, K.V., Mangan, M.T., Newman, S., 1994. Surface degassing and modifications to vesicle size distributions in active basalt flows. Journal of Volcanology and Geothermal Research 61(1), 45-68 http://doi.org/10.1016/0377-0273(94)00015-8.
Colombier, M., Bruce, V., Houghton, B.F., Caceres, F., Scheu, B., Kueppers, U., Thivet, S., Gurioli, L., Montan, C., Soldati, A., Di Muro, A., Dongwell, D.B., 2021. Degassing and gas percolation in basaltic magmas. Earth and Planetary Science Letters 573, 117-134 https://doi.org/10.1016/j.epsl.2021.117134
Copley, A., Jackson, J., 2006. Active tectonics of the Turkish-Iranian Plateau. Tectonics 25, TC6006 https://doi.org/10.1029/2005TC001906
Cox, K.G., Bell, J.D., Pankurst, R.J., 1979. The interpretation of Igneous rocks, Londan, Unwin – Hyman Ltd., p.450 http://dx.doi.org/10.1007/978-94-017-3373-1
Fitton J.G., 2007. The OIB paradox. Article in Special Paper of the Geological Society of America 430, 387-412 http://doi.10.1130/2007.2430(20)
Fitton, J.G., Saunders, A.D., Norry, M.J., Hardarson, B.S., Taylor, R.N., 1997. Thermal and chemical structure of the Iceland plume. Earth and Planetary Science Letters 153, 197-208 https://doi.org/10.1016/S0012-821X(97)00170-2
Hastie, A.R., Kerr, A.C., Pearce, J.A., Mitchell, S.F., 2007. Classification of altered volcanic island arc rocks using immobile trace elements: development of the Th-Co discrimination diagram. Journal of Petrology 48(12), 2341-2357 http://dx.doi.org/10.1093/petrology/egm062
Higgins M.D., 2006. Quantitative textural measurement in igneous and metamorphic petrology. Cambridge university press, p.265 https://doi.org/10.1017/CBO9780511535574
Hooper, P.R., Hawkesworth, C.J., 1993. Isotopic and geochemical constraints on the origin and evolution of the Columbia River Basalt. Journal of Petrology 34 (1), 203-246 https://doi.org/10.1093/petrology/34.6.1203
Jones, M.R., Soule, S., Klein, F., 2020. Quantitative vesicle analyses and total CO2 reconstruction in mid-ocean ridge basalts. Journal of Volcanology and Geothermal Research http://doi.:10.1016/j.jvolgeores.2020.107109.
Keskin, M., Chugaev, A.V., Lebedev, V.A., Sharkov, E.V., Oyan, V., Kavak, O., 2012. Geochronology and origin of mantle sources for Late Cenozoic intraplate volcanism in the frontal part of the Arabian Platein the Karacadağ Neovolcanic Area of Turkey. Part1.The results of isotope – geochronologic studies. Journal of Volcanology and Seismology 6, 31-42 https://doi.org/10.1134/S0742046312060048
Keskin, M., Pearce, J.A., Mitchell, J.G., 1998. Volcano-stratigraphy and geochemistry of collision-related volcanism on the Erzurum-Kars Plateau, northeastern Turkey. Journal of Volcanology and Geothermal Research 85, 355-404 https://dx.doi.org/10.1016/S0377-0273(98)00063-8
Kheirkhah, M., 2013. New investigation on the petrogenesis and dating of basic Quaternary lavas in the NW Iran. Iranian Earth Sciences (in Persian) 88, 205-218 https://doi.org/10.22071/gsj.2013.53694
Kheirkhah, M., Allen, M.B., Emami, M.H., 2009. Quaternary syn-collision magmatism from the Iran/Turkey borderlands. Journal of Volcanology and Geothermal Research 182, 1-12 https://doi.org/10.1016/j.jvolgeores.2009.01.026
Kretz R., 1983. Symbols for rock-forming minerals. American mineralogist 68, 277-279
MacDonald, R., Belkin, H.E., Wall, F., Bagiński, B., 2009. Compositional variation in thechevkinite group: new data from igneous and metamorphic rocks. Mineralogical Magazin 73, 777-796 http://doi. 10.1180/0026461026660078
McDonough, W.F., Sun, S.S., Ringwood, A.E., Jagoutz, E., Hofmann, A.W., 1992. Potassium, rubidium, cesium in the Earth and Moon and the evolution of the Earth's mantle. Geochimica et Cosmochimica Acta 56, 1001-1012 https://doi.org/10.1016/0009-2541(94)00140-4
Moazzen, M., Modjarrad, M., 2005. Contact metamorphism and crystal size distribution studies in the Shivar aureole, NW Iran. Geological Journal 40, 499-517 https://doi.org/10.1002/gj.1025
Modjarrad, M., 2022a. Crystal Size Distribution of garnet and geochemistry of the Hal Hal Chaldoran garnet amphibolites-Northwest corner of Iran. Advanced Applied Geology (in Persian) 12(3), 537-556 https://doi.10.22055/AAG.2021.37891.2237
Modjarrad, M., 2022b. Geochemistry and crystal shape, size and spatial distribution in arc-related gabbro, Urmia, NW Iran. Acta Geochimica https://doi: 10.1007/s11631-022-00557-8
Modjarrad, M., 2022c. The importance of quantitative measurements of the texture of metamorphic rocks. Petrology (in Persian) 12(48), 121-140 https://doi.org/10.22108/ijp.2022.132883.1271
Modjarrad, M., 2015. Crystal size distribution of amphiboles from Bezow dacites, Urmia, Iran. Neues Jahrbuch Fur Geologie Und Palaontologie- Abhandlungen 276, 101-110
Modjarrad, M., Sheykhbaglou, S., 2016a. Crystal Size Distribution of kyanite and staurolite from Hamza Qassim and Khazai Bala Metapelites-southeast Shahin-Dezh; confirmation to regional metamorphism conditions at the area. Iranian Journal of Crystallography and Mineralogy (in Persian) 24, 99-108 http://doi.20.1001.1.17263689.1395.24.1.8.0
Modjarrad, M., Sheykhbaglou, S., 2016b. Crystal size distribution of amphibole and plagioclase from Zanbil adakitic dacites, Urmia-Iran: Evidence for magma mixing and textural coarsening. Acta Geodynamic Geomaterials 181, 89-101
Modjarrad, M., 2019. Crystal size distribution studies on the leucite, pyroxene and olivine at the eastern Urmia Lake volcanic rocks- magma mixing possibility and residence time at the chamber. Iranian Journal of Crystallography and Mineralogy (in Persian) 27, 55-68 https://doi.10.29252/ijcm.27.1.55
Modjarrad, M., 2020. Effect of whole rock chemistry on the crystal size distribution of garnet in metapelites, comparison of Shahindezh schist with Dorbeh hornfelses. Iranian Journal of Crystallography and Mineralogy (in Persian) 28, 297-310 https://dx.doi.org/10.29252/ijcm.28.2.297
Nabavi, M., 1976. Introduction to the geology of Iran. Iranian geological Survey (in Persian), p.109
Okay, A.I., Tüysüz, O., 1999. Tethyan sutures of northern Turkey, in Durand, B., Jolivet, L., Horváth F., and Séranne, M., eds., The Mediterranean Basins: Tertiary Extension within the Alpine Orogen: Geological Society of London Special Publication156, 475-515 https://doi.org/10.1016/j.gsf.2019.05.010
Pearce, J., 1982. Trace Element Characteristics of Lavas from Destructive Plate Boundaries. In book: Andesites: Orogenic Andesites and Related Rocks, Publisher: John Wiley and Sons, Editors: R.S. Thorpe, 525-548.
Pearce, J.A., 1996. A user’s guide to basalt discrimination diagrams. Geological Association of Canada, Short Course Notes 12, 79-113
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(1), 63-81
Sahandi, M.R., 2003. The Maku 1:100000 Geological Sheet. Geological Survey of Iran, number 4968
Schandl E.S., Gorton M.P., 2002. Application of high field strength elements to discrimination tectonic setting in VMS environments. Economic Geology 79, 629-642 https://doi.org/10.2113/gsecongeo.97.3.629
Shabanian, E., Acocella, V., Gioncada, A., Ghasemi, H., Bellier, O., 2012. Structural control on volcanism in intraplate post collisional settings: Late Cenozoic to Quaternary examples of Iran and Eastern Turkey. Tectonics 31, TC3013 https://doi.org/10.1029/2011TC003042
Shea, T., Houghton, B.F., Gurioli, L., Cashman, K.V., 2010. Textural studies of vesicles in volcanic rocks: An integrated methodology. Journal of Volcanology and Geothermal Research 190, 271-289
Shervais, J.W., 1982. Ti-V plots and petrogenesis of modern and ophiolitic lavas. Earth and Planetary Sciences Letters 23, 319-351
Sluggett, C.L., 2003. Quaternary alkaline and calc-alkakine basalts in southern British Colombia: Mixed signals from mantle sources above the southern edge of the juan de fuca – pacific slab window. Master of Science Thesis, University of British Colombia, p.164
Srivastava, R.K., Singh, R.K., 2004. Trace element geochemistry and genesis of Precambrian sub-alkaline mafic dikes from the Central Indian Craton: evidence for mantle metasomatism. Journal of Asian Earth Sciences 23, 373-389 https://doi:/10.1016/A1367-9120(03)00150-0
Stampfli, G.M., Borel, G.D., 2002. A plate tectonic model for the Paleozoic and Mesozoic constrained by dynamic plate boundaries and restored synthetic oceanic isochrons. Earth and Planetary Science Letters 196, 17-33 https://doi.org/10.1016/S0012-821X(01)00588-X
Sun, S.S., McDonough, W.F., 1989. Chemical and isotopic systematic of oceanic basalts: implications for mantle composition and processes. Geological Society of London, Special Publication 42(3), 313-345
White, W.M., 2005. Geochemistry. Wiley-Blackwell, UK, p.701ISBN: 978-1-119-43805-2
Woodhead, J.D., Eggins, S., Gamble, J., 1993. High field strength and transition element lyitematics in island arc and back-arc basin basalts: evidence for multi-phase melt extraction and a depleted mantle wedge. Earth and Planetary Science Letters 114, 491-504
Yang, W., Teng, F.Z., Zhang, H.F., 2009. Chondritic magnesium isotopic composition of the terrestrial mantle: A case study of peridotite xenoliths from the North China craton. Earth and Planetary Science Letters 288, 475-482