ویژگی های کانی شناختی و ژئوشیمیایی توده گرانیتوئیدی کوه سورمه، شمال باختر نهبندان؛ خاور بلوک لوت

نوع مقاله: مقاله پژوهشی

نویسندگان

گروه زمین‌شناسی، دانشکده علوم پایه، دانشگاه سیستان و بلوچستان

چکیده

گرانیتوئید کوه سورمه در جنوب­خاوری استان خراسان جنوبی و 50 کیلومتری شمال باختری شهرستان نهبندان قرار دارد. از لحاظ تقسیمات زمین­شناسی ایران این توده در محل اتصال بخش خاوری پهنه لوت و زون زمین­درز سیستان واقع شده است. این توده­ از تعدادی توده کوچک به صورت استوک مانند و منقطع با روند عمومی شمال­باختری-جنوب­خاوری در داخل مجموعه­های فلیشی منتسب به سازند شمشک؟ برونزد دارد؛ پیکره اصلی آن ترکیب دیوریتی و گرانودیوریتی دارد. پلاژیوکلاز، کوارتز، آلکالی­فلدسپار، هورنبلند و بیوتیت مهم­ترین کانی­های سازنده­ی توده­ها می­باشند. گرانیتوئید کوه سورمه کالکوآلکالن، متاآلومینوس تا پرآلومینوس و دارای خاستگاه آذرین (I) است.  شواهدی چون حضور هورنبلند، بیوتیت و نبود موسکوویت و داده‌های ژئوشیمیایی این گرانیتوئید نشان از خاستگاه آذرین این توده دارد. این توده­ها دارای غنی­شدگی از عناصر نادر خاکی سبک (LREE) و فقیر شدگی از عناصر نادر خاکی سنگین (HREE) با الگوی مشابه می­باشند، این اختصاصات به احتمال بیانگر منشاء مشترک آن­ها است. نمودارهای جداکننده­ی محیط­های زمین­ساختی جایگاه گرانیتوئیدهای کوه سورمه را وابسته به کمان­های آتشفشانی حاشیه قاره معلوم می­دارد. تغییرات نـسبت­های Th/Yb و Ta/Yb نـشان می­دهد که ماگمای سازنده واحدهای گرانیتوئیدی متعلق به زون­های فرورانشی غنی شده می­باشند.

کلیدواژه‌ها


عنوان مقاله [English]

Mineralogy and geochemistry properties of Surma granitoids, Northeast Nehbandan, East of Lut block

نویسندگان [English]

  • Habib Biabangard
  • Jamila tayabi
چکیده [English]

Abstract: Surme granitoid plutons are located southeast of Southeastern Khorasan province and 50Km in Northwestern of Nehbandan city. Basd on geological of Iran classification this pluton is located at the junction of the eastern part of Lut and Sistan suture zone. The mass is composed of a small mass number such as stocks with the general trend northwest - southeast that interrupted flysch series and outcroup to Shemshak formation? Main body of pluton is Diorite and granodiorite composition. Plagioclase, quartz, alkali feldspar, hornblende and biotite are the main minerals component of this pluton. Surme granitoid is Calc- alkaline, metaluminous to peraluminous and I type. Depletion of Nb, P, Yb,Y and Ti elements suggest that the parent magmas relate to the subduction zone setting and affected by crustal contamination.These plutons have enriched in light rare earth elements (LREE) and depleted in heavy rare earth elements (HREE) with similar patterns.These characteristics indicate the likely origin of magma that originated from the subducted oceanic crust and metasomatisem with wedge mantle and finally contamination with crustal material. According to the tectonic discrimination diagrams surme granitoid has related to the active continental crust. Surme granitoid have low Sr (135- 205ppm), Sr/Y and plot predominantly in the field of mantle- derived arc magmas (normal Calc- alkaline rocks). Variations in Th/Yb and Ta/Yb ratios indicate that the resulted magma of granitoids unites have been affected by crustal contamination en route to the surface.

کلیدواژه‌ها [English]

  • Continental margin
  • Surme granitoid
  • Nehbandan
  • Lut block
[1]  Aghanabati, E (2004) Geology of Iran. Global Security Institute, Tehran (in Persian).

[2] Ahmadibonakdar, S (2010) Distribution and petrogenitic application of REE elements in the Biotite- Turmaline Pegmatoid South of Nehbandan. M.Sc Thesis, university of Sistan and Baluchestan, 180 (in Persian).

[3] Barbarin, B (1999) A review of the relationships between granitoid types, their origins and the geodynamic environments, Lithos.46: 605–626.

[4] Chappell, B.W., and White, A.J.R (1992) Two contrasting granite types, 25 years later. Australian Journal of Earth Sciences, 48:489-499.

[5] Esmaeily, D (2002) Petrology and geochronology of Shah-kuh granitoid (south Birjand), with reference to tin mineralization. Ph.D Thesis, university of Trbiat Modaras, Tahran, Iran, 270.

[6] Esmaeily, D., Valizadeh, M.V., HossanZadeh, J., and Bloon, H (2004) Petrology of Shah-kuh granite (eastern Iran) and radiometric age with K-Ar method, geology of science, 41: 142-160.

[7] Esmaeily, D., Nedeec, A., Valizadeh, M.V., Moore, F., and Catten, j (2004) Petrology of the Jurassic Shah-kuh granite (eastern Iran), with reference to tin mineralization: Journal of Asian Earth Siences, 30: 961-980.

[8] Eggleton R. A., and Benfield J. F (1985) The alteration of granitic biotite to chlorite, American Mineralogist 70: 902-910.

[9] Frost B. R., and Frost C. D (2008) A Geochemical Classification for Feldspathic Igneous Rocks, Journal of Petrology 49: 1955-1969.

[10] Frost B. R., Barnes C. G., Collins W. J Arculus R. J., Ellis D. J., and Frost C.D. A (2001) Geochemical classification for granitic rocks, Journal of Petrology42: 2033-2048.

[11] Ghasemi, H., Sadegheian, M., Kord, M., and Khanalizadeh, A (2010) The evolution mechanisms of Zahedan granitoidic batholith, Southeast Iran, journal of Iranin of crystallography and Mineralogy, 17: N.4. 552- 578(in Persian),

[12] Gill. R (2010) Igneous rocks and processes, department of earth sciences Royal Holloway University of London. 472.

[13] Ghonjalipour, R (2013) Mineralogy and Petrology  Rigi and Abdullahi  granitoid, Weast of Dehsalm, east of Lut block.M.Sc thesis, university of Sistan and Baluchestan, 184(in Persian.

[14] Hamzapour, B (1993) Geological Quadrangle map of Chaharfarsakh 1:100000, Geological Survey and Mineral Exploration of Iran, Tehran (in Persian).

[15] Harker, A (1909) The natural history of igneous rocks. Methneu, London. 344.

[16] Harris N.B.W., Pearce J.A., and Tindle A.G (1986) Geochemical characteristics of collision-zone magmatism. In: Coward, M.P., Ries, A.C. (Eds.), Collision Tectonics, Geological Society London, Special Publication 19, 67–81.

[17] Kaygusuz A., Siebel W., Sen C., and Satir M (2008) Petrochemistry and petrology of I- type granitoids in an arc setting: the composite Torul pluton, Eastern Pontides, NE Turkey, International Journal of Sciences 97: 739- 764.

[18] Martin, H (1993) The mechanism of petrogenesis of the Archean continental crust comparison with modern processes, Lithos 30:373–388.

[19] Maniar, P. D., and Picolli. P. M (1989) Tectonic discrimination of granitoid. Geological Society of America Bulletin 101:635-643.

[20] Miyashiro, A (1974) Nature of alkali Volcanic rocks Series, Contribution Mineral, Petrology  66:91-104.

[21] Middlemost, E.A.K (1985) Magma and magmatic rocks: An Introduction to igneous petrology. Longman Group U.K 73-86.

[22] Najafzade, M (2014) petrogenesis of Chaharfarsakh granitoid, Weast of Nehbandan, east of Iran. M.Sc thesis, university of Sistan and Baluchestan, 235 (in Persian).

[23] Patino Douce A. E (1999) What do experiments tell us about the relative contributions of crust and mantle to the origins of granitic magmas? In: A. Castro, C. Fernandez and Vigneresse, J. L. (Eds.): Understanding granites: Intergrating new and classical techniques, Geological Society of London, Special Publication 168: 55-75.

[24] Pearce, J. A., Harris, N.B.W. and Tindle, A. G (1984) Trace element discrimination diagram for the tectonic interpretation of granitic rocks. Journal of Petrology 25:956-983.

[25] Rollinson, H (1993) Using geochemical data: evaluation, presentation, interpretation, Longman Scientific and Technical London. 352.

[26] Shand, S. J (1943) Eruptive rocks, Their genesis, composition, classification, and their relations to ore - deposits. John Wiley & Sons, Inc., New York.

[27] Sun, S. S., and Mc Donough, W. F (1989) Chemical and isotopic systematic of oceanic basalts: implication for mantle composition and processes. In: Magmatism in oceanic basalts (Eds. Saunders, A. D. and Norry, M. J). Special Publication 42: 313-345. Geological Society, London.

[28] Tolabinegad, E (2013) petrology, mineralogy and petrogenesis of Sefidkuh granitoid, Nehbandan, east of Iran.M.Sc thesis, university of Sistan and Baluchestan, 344.

[29] Wilson, M (2007) Igneous petrogenesis. Uniwin Hyman London, 466.

[30] Whalen J. B., and Chappell B.W (1988) Opaque mineralogy and mafic mineral chemistry of  I- and S-type granites of the Lachlan fold belt, southeast Australia, American Mineralogist73: 281-296.