ژئوشیمی، پتروژنز و تحولات ماگمایی بازالت‌های شمال شهر رضی

نوع مقاله : علمی -پژوهشی

نویسندگان

1 گروه زمین‌شناسی، دانشکده علوم، دانشگاه محقق اردبیلی، اردبیل، ایران

2 گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران

3 گروه زمین‌شناسی، دانشگاه پیام نور، ایران

چکیده

مجموعه‌ای از منشورهای بازالتی در شمال غرب ایران و در شمال شهر رضی (استان اردبیل) با روند شمال غرب – جنوب شرق برون‌زد دارند. کانی‌شناسی اصلی منشورهای بازالتی شامل فنوکریست های پلاژیوکلاز، کلینوپیروکسن (اوژیت) و الیوین با کانی فرعی تیتانومگنتیت و بافت غالب گلومروپورفیریتیک و هیالومیکرولیتی پورفیری می‌باشد. به لحاظ ژئوشیمیایی ماگمای مولد این سنگ‌ها دارای سرشت آلکالن و شوشونیتی است. نمودار عنکبوتی نشانگر غنی شدگی LREE نسبت به HREE بوده و بررسی ژئوشیمیایی گویای ژنز مرتبط با گوشته غنی‌شده است. روند تغییرات اکسیدهای مختلف نسبت به فراوانی SiO2 بیانگر فرایند تفریق عادی است. منشأ ماگمای این سنگ‌ها از ذوب 1 تا 5% گوشته‌ی اسپینل گارنت لرزولیت با غنی شدگی توسط متاسوماتیسم در منشأ با مذاب حاصل از صفحه فرو رو و سیالات و رسوبات همراه آن است. براساس شواهد ذکر شده این الیوین بازالت‌ها در یک حوضه کششی پشت قوس پس از برخورد در امتداد سوچر زون اللهیارلو در ورای کمان ماگمایی کرتاسه ایجاد شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Geochemistry, petrogenesis and magmatic evolution of basalts from north of the Razi city

نویسندگان [English]

  • gholamreza ahmadzadeh 1
  • mohammad mobasher Germi 1
  • Ahmad Jahangiri 2
  • Gahraman Sohrabi 1
  • Marziyeh Rezaeiagdam 3
1 Department of Geology, Faculty of Science, Mohaghegh Ardabili University, Ardabil, Iran
2 Department of Earth Sciences, Faculty of Natural Science, University of Tabriz, Tabriz, Iran
3 Department of Geology, Payame Noor University, Iran
چکیده [English]

IntroductionNorth Razi basalts in Ardabil province are located in the longitude range of º52 º47 to 505 º48 and latitude ˝00 ´00 º39 to ́50 ° 38. North of Razi magmatic region extends to the city of Kalibar (Sudi and Moazzen., 2014) in the southern part of the Caucasus, which has Lower and Middle Eocene basaltic magmas from northeast to southwest. Also it has olivine gabbroic dykes infiltrated in the eastern part of the Middle Eocene to Oligocene. The studied magmatism is restricted by the southern basin of the Caspian Sea on the east and the Allahyarlu ophiolite belt and Aras fault on the west. Allahyarloo melange ophiolite emerges in the southwestern of Lahroud magmatic zones in Cretaceous and pre-Cretaceous. In this research the genesis and tectono-magmatic environment of the Middle and Late Eocene North Razi basalts and their relationship with the the subductional back arc environment, have been investigated.MetodologyAfter field studies, 45 rock samples were selected for the study based on field relationships and petrographic evidence. Then thirty thin sections of the samples were prepared for petrographic studies. To investigate the geochemistry of major and minor elements, 20 samples were sent to the Amdel Laboratory of the University of New South Wales in Australia for chemical analysis by XRF and ICP.DiscussionIn macroscopic studies, North Razi basalts are black in color and melanocrate in terms of color index. Microscopic studies show Plagioclase and clinopyroxene phenocrysts are the main minerals while olivine and titanomagnetite are the lowest manufacturers of these rocks and show glomeroporphiritic and hyalomicrolitic porphiritic texture. The matrix of these rocks is mostly composed of glass with plagioclase microcrystals, small pyroxene granules, small amounts of olivine and opaque minerals. The parent magma of these rocks have alkaline nature regarding geochemical data. Multi-element diagrams indicate the enrichment of LREEs in comparison with HREEs suggesting magma involvement in enrichment of the mantle. Major oxide variation diagrams versus SiO2 confirm the role of normal magma differentiation. Petrological and geochemical evidences suggest 1- 5% partial melting of spinel garnet lherzolite metasomatic mantle as a result of sub ducted slabs and their sedimentary melting. ResultsIn northwestern Iran, north of the Razi city, a series of prismatic basalts are exposed which according to the stratigraphic studies, are related to the Eocene period of the northern part of Talesh zone. Based on geochemistry, the studied rocks have alkaline to shoshonitic nature and have been formed by subtraction of primary magma at relatively high oxygen fugacity. The order of crystallization of minerals was olivine and then the simultaneous crystallization of plagioclase and clinopyroxene occurred, respectively. Examining the trend of changes in major and minor elements indicates a genetic relationship with a basic magma and the effect of the subtraction process. Also, the study of petrogenesis indicates metasomatism of origins by submerged ocean fragments and associated fluids. This is obtained by unbalanced melting of garnet with spinel lerzolitic origin. These olivine basalts were formed in a tensile back arc basin, after collision along the Allahyarlu suture zone, beyond the Cretaceous magmatic arc.

کلیدواژه‌ها [English]

  • Basaltic series
  • Metasomatism
  • Alkaline
  • Razi city
  • Talesh zone
  1. -Alavi, M., 1996. Tectonostratigraphic synthesis and structural style of Alborz mountain system in northern Iran, Journal Geodynamic, v. 21, p. 1-33 (In Persian).
  2. -Aldanmaz, E., 2012. Trace element geochemistry of primary mantle minerals in spinel-peridotites from polygenetic MOR SSZ suites of SW Turkey: constraints from an LA-ICP-MS study and implications for mantle metasomatism, Geological Journal, v. 47, p. 59-76.
  3. -Aldanmaz, E., Pearce, J.A., Thirlwall, M.F. and Mitchell, J.G., 2000. Petrogenetic evolution of late Cenozoic, post-collision volcanism in western Anatolia, Turkey, Journal of Volcanology and Geothermal Research, v. 102, p. 67-95.
  4. -Allen, M.B., Ghassemi, M.R., Shahrabi, M. and Qorashi, M., 2003. Accommodation of the late Cenozoic oblique shortening in the Alborz range, northern Iran, Journal of Structural Geology, v. 25, p. 659-672.
  5. -Allen, M.B., Jackson, J. and Walker, R., 2004. Late Cenozoic reorganization of the Arabia-Eurasia collision and the comparison of short-term and long-term deformation rates, Tectonics, v. 23, p. 1-16.
  6. -Arslan, M. and Aslan, Z., 2006. Mineralogy, petrology and whole-rock geochemistry of the Tertiary granitic intrusions in the Eastern Pontides, Turkey, Journal of Asian Earth Sciences, v. 27, p. 177-193.
  7. -Babakhani, A.R. and Hossein Khani, N., 1997. Geological Quadrangle Map and repot 1:100000, No.5567, Geological Survey of Iran, Lahrud (In Persian).
  8. -Bird, D.E., Hall, S.A., Burke, K., Casey, J.F. and Sawyer, D.S., 2007. Early Central Atlantic Ocean sea floor spreading history, – Geosphere, v. 5, p. 282-298.
  9. -Class, C., Miller, D.M., Goldstein, S.L. and Langmuir, C.H., 2000. Distinguishing melt and fluid subduction components in Umnak Volcanism, Aleutian Arc, Geochemistry Geophysics Geosystems, doi: 10.1029/1999GC000010.
  10. -Cox, K.G., Bell, J.D. and Pankhurts, R.J., 1979. The Interpretation of Igneous Rocks, 450 George Allen and Unwin, London.
  11. -Deer, W.A., Howie, R.A. and Zussmann, J., 1991. An Introduction to Rock-forming Minerals”, Longman, 528 p.
  12. -Didon, J. and Gemaine, Y.M., 1976. Sabalan volkan plioquaternair del Azerbajan orienta (Iran), Etude geologique et petrographique del edfic et de son environment regional these Docteur du 3e cycle, Univ, Grenoi, France, 304 p.
  13. -Eftekhar Nezhad, I., 1975. Briefhistoy and structural development of Azerbijan, Geological Survey of Iran. International Report: 8. (In Persian).
  14. -Fitton, J.G. and Godard, M., 2004. Origin and Evolution of Magmas on the Ontong Java Plateau, In: Fitton, J.G., Mahoney, J.J., Wallace, P.J., Saunders, A.D. (Eds.), Origin and evolution of the Ontong Java Plateau, Geological Society Special Publication, 229. Geological Society of London, London, p. 151-178.
  15. -Floyd, P.A., Kelling, G., Gokcen, S.L. and Gokcen, N., 1991. Geochemistry and tectonic environment of basaltic rocks from the Misis ophiolitic Melange, South Turkey, Chemical Geology. v. 89, p. 263-280.
  16. -Galoyan, G., Rolland, Y., Sosson, M., Corsini, M., Billo, S., Verati, C. and Melkonyan, R., 2009. Geology, geochemistry and 40Ar/39Ar dating of Sevan ophiolites (Lesser Caucasus, Armenia): evidence for Jurassic back-arc opening and hot spotevent between the south Armenian block and Eurasia, Journal of Asian Earth Sciences, v. 34, p. 135-153.
  17. -Guest, B., Horton, B.K., Axen, G.J., Hassanzadeh, J. and McIntosh, W.C., 2007. Middle to late Cenozoic basin evolution in the western Alborz Mountains: implications for the onset of collisional deformation in northern Iran Tectonics, Journal of Asian Earth Sciences 4, v.(25), p. 26-27.
  18. -Harangi, S. and Lenkey, L., 2007. Genesis of the Neogene to Quaternary volcanism in the Carpathian–Pannonian region: role of subduction, extension, and mantle plume, In: Beccaluva, L., Bianchini, G., Wilson, M. (Eds.) Cenozoic Volcanism in the Mediterranean Area: Geological Society of American Special Paper, v. 418, p. 67-92.
  19. -Harker, A., 1909. The natural history of igneous rocks, methuen 220. Landon.
  20. -Hofmann, A.W., 2004. Sampling mantle heterogeneity through oceanic basalts: isotopes and trace elements, (Ed. in Carlson, R.W) the mantle and Core, Volume 2 of Treatise on Geochemistry (eds. Holland, H.D and Turekian, K.K.) 61–101. Elsevier, Oxford.
  21. -Irvine, T.N. and Baragar, W.R.A., 1971. Guide to the chemical classification of the common volcanic rocks, Canadian Journal of Earth Sciences, v. 8(5), p. 523-548.
  22. -Kamber, E., 2012. Back arc basing in the coatmalia zone in Africa, Journal of Geophysical, v. 92, p. 34-62.
  23. -Kazmin, V.G. and Tikhonova, N.F., 2008. Cretaceous-Paleogene Back-arc Basin in the Iran Afghanestan-Pamirs Segment of the Eurasian Active Margin, Earth Sciences, v. 24, p. 118 120.
  24. -Kim, J. and Cho, M., 2003. Low-pressure metamorphism and leucogranite magmatism, NE Yeongnam Massif, Korea. Precambrian Research. v. 122, p. 235-251.
  25. -Kretz, R., 1983. Symbols for rock-forming mineral, American Mineralogist, v. 68, p. 227-279.
  26. -Kuscu, G.G. and Floyd, P.A., 2001. Mineral compositional and textural evidence for magma mingling in the Saraykent volcanics, Lithos, v. 56, p. 207-230.
  27. -LeMaitre, R.W., 1976. The chemical variability of some commn igneous rocks, Journal of Petroleum, v. 17(4), p. 589-637.
  28. -McKenzie, D. and O’Nions, R.K., 1991. Partial melt distribution from inversion of rare earth element concentrations. Journal of Petrology, v. 32, p. 1021-1091.
  29. -Mobashergarmi, M., 2013. Petrography, petrology, geochemistry and petrogenesse survey to basalts in the south of Talesh, MSc thesis, University of Tabriz, Tabriz, Iran (In Persian).
  30. -Mobashergarmi, Z., Akbari, M. and Jamshedi, M., 2015. Geochemistry, Petrogeneses and Origin Magmatic Evolution in the Olivine Gabbro Dikes of SW Germi city, Journal of Petrology, v.(24), p. 65-86(In Persian).
  31. -Mohammadiha, H., Mostafazadeh, M., Gholami, N., 2014. An investigation on the Eocene Pushtasar basaltic lava in relation to Moghan Aulacogene, Arabian Journal of Geosciences, DOI 10.1007/s12517-014-1335-9.
  32. -Morata, D., Oliva, C., Cruz, R. and Suarz, M., 2005. the bandurrias gabbro: Late Oligocene alkaline magmatism in the Patagonian cordillera, Journal of South American Earth Sciences, v. 18, p. 147-162.
  33. -Munker, C., 2000. The isotope and trace element budget of the Cambrian Devil River System, New Zealand: Identification of four source components, Journal of Petrology, v. 41, p. 759-788.
  34. -Nabavi, M.H., 1976. Introduction to geology of Iran, Publication by Geological survey of Iran, 109 p. (In Persian).
  35. -Nelson, S.A., 2010. magmatic differentiation, Petrology, Tulane University, v. 212, p. 15.
  36. -Pearce, J.A. and Stern, R.J., 2013. Origin of Back-Arc Basin Magmas: Trace Element and Isotope Perspectives, American Geophysical Union, doi: 10.1029/166GM06.
  37. -Pearce, J.A., 2005. Mantle preconditioning by melt extraction during f low: Theory and petrogenetic implications, Journal of Petrology, Doi:10.1093/petrology/ egi007.
  38. -Pearce, J.A., Harris, N.W. and Tindle, A.G., 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks, Journal of Petrology, v. 25, p. 956-983.
  39. -Pearce, J.A., Stern, R.J., Bloomer, S.H. and Fryer, P., 2005. Geochemical Mapping of the Mariana Arc-Basin System: Implications for the Nature and Distribution of Subduction Components, Geochemistry Geophysics Geosystems, 2004GC000895.
  40. -Pearce, J.A. and Norry, M.J., 1979. Petrogentic implications of Ti, Zr, y and Nb variations in volcanic rocks, Contributions to Mineralogy and Petrology, v. 69, p. 33-47.
  41. -Plank, T. and Langmuir, C.H., 1998. The chemical composition of sub ducting sediment and its consequences for the crust and mantle, Chemical Geology, v. 145, p. 325-394.
  42. -Prytulak, J. and Elliott, T., 2007. TiO2 enrichment in ocean island basalts, Earth and Planetary Science Letters, v. 263, p. 388-403.
  43. -Righter, K. and Rosas-Lguera, J., 2001. Alkalin Lavas in the Volcanic Front of the Western exican Volcanic Belt: Geology and Petrology of the Ayutla and Tapala Volcanic Fields, ournal of Petrology, p. 2333-2361.
  44. -Rollinson, H.R., 1993. Using Geochemical Data: evaluation, interpretation, presentation, Publishing House, Longman Group, United Kingdom, 374 p.
  45. -Salavati, M. and Fahim Gilani, R., 2014. Petrology and geochemistry of mafic and ultramafic masses rock, East of Amam Zadeh Hashem (south, Gilan), Journal of Economic Geology, v.1(6), p. 87-105 (In persian).
  46. -Salavati, M., Cananian, A., Samadi Sufi, A. and Zaeimnia, F., 2009. minerals chemistry of Ophiolite Complex in Caspian Sea (East Gilan), Journal of Crystallogy and Mineralogy, v. 1(17), p. 149-166.
  47. -Shafaii Moghadam, M.H. and Shahbazi Shiran, S.H., 2010. Geochemistry and petrogenesis of volcanic rocks from the northern part of the Lahrud region (Ardabil): An example of shoshonitic occurrence in northwestern Iran, Journal of Petrology, v. 4, p. 16-31(In Persian).
  48. -Sinton, J.M., ford, L.L., Chapplle, B. and Mcculloch, M.T., 2003. Magma genesis and mantel heterogeneity in the Manus BAB Papua New Guiea, Journal of Petrology, v. 44, p. 59-195.
  49. -Stern, C.R. and Kilian, R., 1996. Role of the subducted slab, mantle wedge and continental crust in the generation of adakites from the Andean Austral Volcanic Zone, Contributions to Mineralogy and Petrology, v. 123, p. 263-281.
  50. -Stocklin, J., 1997. Structural Correlation of the Alpine ranges between Iran and Central Asia, Societe geologique de France, Paris. v. 8, p. 333-353.
  51. -Sudi, M. and Moazzen, M., 2014. Role of the Allahyarlu ophiolite in the tectonic evolution of NW Iran and adjacent areas (Late Carboniferous – Recent), Central European Geology, v. 57, p. 363-383, DOI:10.1556/CEuGeol.
  52. -Sudi, M. and Jahangiri, A., 2010. Petrography and tectonic setting from ophiolite complex of Allah Yarlu, 29 th Symposium Geoscience, Tehran, Iran.
  53. -Sun, S. and McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts, In implication for mantle composition and processes, Special Publication, London, 387 p.
  54. -Taylor, B. and Martinez, F., 2003. Back-arc basin basalt systematics, Earth Planet, Science Letters, v. 210, p. 481-497.
  55. -Taylor, S.R. and McLennan, S.M., 1981. The composition and evolution of the continental crust: rare earth element evidence from sedimentary rocks, Philosophical Transactions of the Royal Society, v. 301, p. 381-399.
  56. -Turner, S., Hawkesworth, C., Rogers, N., Bartlett, J., Worthington, T., Hergt, J., Pearce, J. and Smith, I., 1997. U-Th disequilibrium, magma petrogenesis, and flux rates beneath the depleted Tonga-Kermadec island arc, Geochimica et Cosmochimica Acta, v. 61, p. 4855-4884.
  57. -Verdle, C., 2009. Cenozoic geology of Iran: An integrated study of extensional tectonics and related volcanism, Ph.D. Thesis, California Institute of Technology, Pasadena, California.
  58. -Wang, Y., Fan, W. and Guo, F., 2003. Geochemistry of early Mesozoic potassium-rich dioritesgranodiorites in southeastern Hunan Province, South China” Petrogenesis and tectonic implications, Geochemical Journal, v. 37, p. 427-448.
  59. -Wayer, S., Munker, C. and Mezger, K., 2003. Nb/Ta, Zr/Hf and REE in the depleted mantle: implications for the differentiation history of the crust-mantle system, Earth and Planetary Science Letters. V. 205, p. 309-324.
  60. -Weaver, B. and Tarney, J., 1984. Empirical approach to estimating the composition of the continental crust, Nature, v. 310, p. 575-580.
  61. -Wedepohl, K.H., 1995. The composition of the continental crust, Geochemistry Cosmochemisty Acta, v. 59, p. 1217-1232.
  62. -Wilson, M. and Downes, H., 2006. Tertiary-Quaternary intraplate magmatism in Europe and its relationship to mantle dynamics, Geological Society, London, 325 p.
  63. -Yoder, H.S. and Tilley, C.E., 1962. Origin of basalt magmas: an experimental study of natural and synthetic rock systems, Journal of Petrology, v. 3, p. 342-532.
  64. -Zakariadze, G.S., Dilek, Y., Adamia, S.M., Oberhansli, R.S., Karpenko, S.M., Bazylev, B.A. and Soloveva, N., 2007. Geochemistry and geochronology of the Neoproterozoic Pan-African Transcaucasian Massif (Republic of Georgia) and implications for island arc evolution of the late Precambrian Arabian– Nubian Shield, – Gondwana Research, v. 11, p. 92-108.
  65. -Zhao, J.H. and Zhou, M.F., 2007. Geochemistry of Neoproterozoic mafic intrusions in the Panzhihua district (Sichuan Province, SW China) Implications for subduction - related metasomatism in the upper mantle, Precambrian Research, v. 152, p. 27-47.
  66. -Pearce, J.A. and Cann, J.R., 1973. Tectonic Setting of basic volcanic rocks determined using trace element analysis, Earth and Planetary Science Letter, v. 19, p. 290-300.