نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکترا، گروه زمین شناسی، دانشکده علوم پایه، دانشگاه هرمزگان، بندرعباس، ایران

2 استادیار، گروه زمین شناسی، دانشکده علوم پایه، دانشگاه هرمزگان، بندرعباس، ایران

3 استاد، دانشکده زمین شناسی، پردیس علوم، دانشگاه تهران، تهران، ایران

4 استادیار، سازمان زمین‎شناسی و اکتشافات معدنی کشور، تهران، ایران

چکیده

توده­های نفوذی رشتخوار در شمال ­خاور شهرستان رشتخوار (استان خراسان رضوی)، درلبه­خاوری­کمربندآتشفشانی- نفوذیخواف- کاشمر- بردسکن،شمالگسلدرونه ودرجنوب پهنه­ساختاری سبزوارواقعشده‎اند. ترکیب سنگ­شناسی توده­های نفوذی عمدتاً شامل سینیت، مونزوسینیت، مونزونیت، سینیت­، مونزونیت و دیوریت ­پورفیری با کمترین گسترش است که دارای بافت گرانولار و پورفیری هستند. براساس داده‎های ژئوشیمیایی، توده­های نفوذی رشتخوار از نوع کالک­آلکالن با ماهیت پتاسیم بالا تا شوشونیتی و متاآلومین هستند و در گروه­ گرانیت­های نوع I قرار دارند. الگوی تغییرات عناصر کمیاب­خاکی وکمیاب بهنجار شده نسبت به کندریت و گوشته ­اولیه نشان­دهنده­ غنی­شدگی این سنگ­ها از LILE،LREE و Th، تهی­شدگی از HFSE و تهی­شدگی اندک از HREE و Y، همراه با آنومالی­های منفی Nb، Ta وTi است، این ویژگی­ها موقعیت زمین­ساختی حاشیه فعال قاره­ای و  پس از برخوردی را نشان می­دهند. مقادیر پایین از نسبت­های Nb/La، Nb/U وCe/Pb و مقدار Sm/Yb= 2.8-3.9 نشان­دهنده­ آلایش­کم ماگما با پوسته­ بالایی است. عامل اصلی فعالیت ماگمایی در ناحیه رشتخوار ذوب بخشی­گوه­­گوشته­ای متاسوماتیسم ­شده شبیه (E-MORB) با ترکیب اسپینل- لرزولیت دارای فلوگوپیت است. بر اساس الگوی چند عنصری و REE و نسبت K2O/Na2O، در سنگ­های نفوذی رشتخوار آلایش و آمیختگی با ماگمای اسیدی پوسته­­زیرین در رخساره­ آمفیبولیتی به­علت گرمای ماگمای گوشته­ای و فرایند AFC در تکامل ماگما نقش مهمی داشته است. ترکیب پتاسیک نمونه­ها، غنی­شدگی از Rb، Ba، K، Th، U و Pbو تهی­شدگی از Nb، Ta، Tiبه همراه فراوانی بالای La(ppm 29<) نشانگر نقش پوسته­­زیرین در تکامل ماگمای سازنده سنگ­های­ نفوذی است. باتوجه به اطلاعات به دست آمده ازمطالعات صحرایی،سنگ­شناسی،ژئوشیمی و نمودارهای تمایز محیط­های زمین‌ساختی­توده نفوذی رشتخوار در یک محیط کششی پس از برخورد وابسته به حاشیه ­قاره­ای ازذوب گوشته- پوسته­زیریندرکمربند خواف- کاشمر- بردسکن تشکیل شده­اند.

کلیدواژه‌ها

کتابنگاری
آقانباتی، ع.،  1385- زمین­شناسی ایران، سازمان زمین­شناسی و اکتشافات معدنی کشور، وزارت صنایع و معادن، 608 ص.
تیموری، خ.، 1391- پتروگرافی، ژئوشیمی و منشأ کانسار آهن رشتخوار و سنگ های میزبان مرتبط با آن، پایان­نامه کارشناسی­ ارشد، دانشگاه سیستان و بلوچستان، 145 ص.
گل­محمدی، ع.، 1393- پتروژنز توده­های نفوذی، پترولوژی اسکارن، منشأ محلول­های کانه­ساز و مغناطیس­سنجی معدن سنگ آهن شرق ایران (سنگان)، رساله­ دکترا، دانشگاه فردوسی مشهد، 484 ص.
یوسفی­سورانی، ل.، 1385- پتانسیل­یابی ورقه 100000/1 دولت­آباد با استفاده از داده­های ژئوشیمی رسوبات رودخانه­ای، ژئوفیزیکی و پردازش و تفسیر داده­های ماهواره­ای، پایان­نامه کارشناسی ارشد، دانشگاه فردوسی مشهد، 387 ص.
 
 
References
Alavi, M., 1991- Tectonic map of the Middle East, Scale 1: 5,000,000. Geological Survey and Mining Exploration of Iran.
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.
Alizadeh, E., Ghadami, Gh., Esmaeily, D., Ma, Ch., Lentz, D. R., Omrani, J. and Golmohammadi, A., 2018- Origin of 1.8 Ga zircons in Post Eocene mafic dikes in the Roshtkhar area, NE Iran. International Geology Review, V. 60, p. 1855-1882.
Almeida, M. E., Macambira, M. J. B. and Oliveira, E. C., 2007- Geochemistry and zircon geochronology of the I-type high-K calcalkaline and S-type granitoid rocks from southeastern Roraima, Brazil: Orosirian collisional magmatism evidence (1.97-1.96 Ga) in central portion of Guyana Shield. Percambrian Research, V, 155, p, 69-97.
Altherr, R., Hall, A., Henger, E., Langer, C. and Kreuzer, H., 2000- High potassium, calc-alkaline I-type plutonism the Euro peanvariscides Northern Vosges (Farance) and NorthenSchwarzwald (Germany). Lithos, V. 50, p. 51-73.
Atherton, M. P. and Ghani, A. A., 2002- Slab breakoff: a model for Caledonian, late granite syncollisionalmagmatism in the orthotectonic metamorphic zone of Scotland and Donegal, Ireland. Lithos, V. 62, p. 65-85.
Bonin, B., 2004- Do coeval mafic and felsic magmas in post-collisional to within-plate regimes necessarily imply two contrasting, mantle and crustal, sources? A review. Lithos, V. 78: p. 1-24.
Boomeri, M., 1998- Petrography and Geochemistry of the Sangan Iron Skarn Deposit and Related Igneous Rocks, Northeastern Iran. [Ph.D. thesis], Akita University, Japan, 226p.
Brenan, J. M., Shaw, H. F., Reyerson, F. J. and Phinney, D. L., 1995- Mineral-aqueous Fluid partitioning of trace elements at 900οC and 2 Gpa: Constraints on the rare element chemistry of mantle and deep crustal fluids. GeochimicaetCosmochimicaActa, V. 59, p. 3331-3350.
Brown, G. C., Thorpe, R. S. and Webb, P. C., 1984- The geochemical characteristics of granitoids in contrasting arcs and comments on magma sources. Journal of Geological Society of London, V. 141, p. 413-426.
Burnham, C. W., 1979- Magmas and hydrothermal fluids. In: Barnes, H.L., (Eds.), Geochemistry of hydrothermal ore deposits. John Wiley and Sons, New York, 71-136p.
Chappell, B. W. and White, A. J. R., 1992- I- and S-type granites in the Lachlan Fold belt.Transactions of the royal society of Edinburgh. Earth Science Reviews, V. 83, p. 1-26.
Chappell, B. W. and White, A. J. R., 2001- Two contrasting granite type: 25 years later. Journal of Earth Sciences, V. 48, p. 489-499.
Conceição, R. V. and Green, D. H., 2004- Derivation of potassic (shoshonitic) magmas by decompression melting of phlogopite+pargasitelherzolite. Lithos, V. 72, p. 209-229.
Condie, K. C., 1989- Geochemical changes in basalts and andesites across the Archean-Proterozoic boundary: identification and significance. Lithos, V. 23, p. 1-18.
De Yoreo, J. J., Lux, D. R. and Guidotti, C. V., 1989- The role of crustal anatexis and magma migration in the thermal evolution of regions of thickened continental crust. In: Daly, J. S., Cliff, R. A., Yardley, B. W. D., (Eds.,), Evolution of metamorphic belts. Geological Society London, Special Publication, V. 43, p. 187-202.
Defant, M. J. and Drummond, M. S., 1990- Derivation of some modern arc magmas by melting of young subducted lithosphere. Nature, V. 347, p- 662-665.
Esperanca, S., Crisci, M., de Rosa, R. and Mazzuli, R., 1992- The role of the crust in the magmatic evolution of the island Lipari (Aeolian Islands, (Italy). Contributions to Mineralogy and Petrology, V. 112, p. 450-462.
Fan, W. M., Gue, F., Wang, Y. J. and Lin, G., 2003- Late Mesozoic calc-alkaline volcanism of post-orogenicextention in the northen Da Hinggan Mountains, northeastern China. Journal of Volcanology and Geothermal Research, V. 121, p. 115- 135.
Foley, S. F., Barth, M. G. and Jenner, G. A., 2000- Rutile/melt partition coefficients for trace elements and an assessment of the influence of rutile on the trace element characteristics of subduction zone magmas. Geochimica and CosmochimicaActa, V. 64, p. 933-938.
Furman, T. and Graham, D., 1999- Erosion of lithospheric mantle beneath the East African Rift system: Geochemical evidence from the Kivu volcanic province, Lithos, V. 48, p. 237-262.
Furman, T., 2007- Geochemistry of East African Rift Basalts: on overview. Journal of African Earth Science, V. 48, p. 147-160.
Girardi, J. D., Patchett, P. J., Ducea, M. N., Gehrels, G. E., Cecil, M. R., Rusmore, M. E., Woodsworth, G. J., Pearson, D. M., Manthei, C. and Wetmore, P., 2012- Elemental and isotopic evidence for granitoid genesis from deep-seated sources in the Coast mountains batholith, British Columbia. Journal of Petrology, V. 53, p. 1505-1536.
Golmohammadi, A., Karimpour, M. H., MalekzadehShafaroudi, A. and Mazaheri., S. A., 2015- Alteration-mineralization, and radiometric ages of the source pluton at the Sangan iron skarn deposit, northeastern Iran: Ore Geology Reviews, V. 65, p. 545-563.
Gou, L., Zhang, L., Tao, R. and Du, J., 2012- A geochemical study of syn-subduction and post-collisional granitoids at Muzhaerte River in the Southwest Tianshan UHP belt, NW China. Lithos, V. 136-139, p. 201-224.
Grove, T. L. and Donnelly-Nolan, J. M., 1986- The evolution of young silicic lavas at Medicine Lake volcano, California: Implications for the origin of compositional gaps in calc- alkaline series lavas. Contributions to Mineralogy and Petrology, V. 92, p. 281-302.
Harris, N. B. W., Duyverman, H. J. and Almand, D. C., 1983- The trace element and isotope geochemistry of the Sabaloka igneous complex, Sudan. Journal of Geological Society of London, V. 140, p. 245-256.
Harris, N. B. W., Kelley, S. and Okay, A. L., 1994- Post- collision magmatism and tectonism in northwest Anatolia. Contributions to Mineralogy and Petrology, V. 117, p. 241-252.
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, V. 19, p. 67- 81.
Hastie, A. R., Kerr, A. C., Pearce, J. A. and 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, V. 48, p. 2341-2357.
Hermann, J., 2002- Allanite, Thorium and light rare earth element carrier in subducted crust. Chemical Geology, V. 192, p. 289-306.
Hofmann, A. W., Jochum, K. P., Seofert, M. and White, W. M., 1986- Nb and Pb in oceanic basalts: new constrains on mantel evolution, Earth and Planetary Science Letters,V. 79, p. 33- 45.
Hole, M. J., Saunders, A. D., Marriner, G. F. and Tarney, J., 1984- Subduction of pelagic sediments: implication for the origin of Ceanomalous basalts from Alexander Islands. Journal of Geological Society of London, V. 141, p. 453-472.
Kampunzu, A. B., Tombale, A. R., Zhai, M., Bagai, Z., Majaule, T. and Modisi, M. P., 2003- Major and trace element geochemistry of plutonic rocks from Francistown, NE Botswana: evidence for a Neoarchaean continental active margin in the Zimbabwe craton. Lithos, V. 71, p. 431-460.
Karsli, O., Dokuz, A., Uysal, İ., Ketenci, M., Chen, B. and Kandemir, R., 2012- Deciphering the shoshoniticmonzonites with I-type characteristic, the Sisdaği pluton, NE Turkey: Magmatic response to continental lithospheric thinning. Journal of Asian Earth Sciences, V. 51, p. 45-62.
Kay, S. M. and Mpodozis, C., 2001- Central Andes ore deposits linked to evolving shallow subduction systems and thickening crust. Geological Society of American, V.11, p. 4-9.
KholghiKhasraghi, M. H., Naderi, N. and AlaviNaini, M., 1996- Geological map of Iran, Dolat-Abad, Scale 1:100,000.Geological Survey of Iran, Tehran.
Kolb, M., Von Quadt, A., Peytcheva, I., Heinrich, C. A., Fowler, S. J. and Cvetković, V., 2013- Adakite-like and normal arc magmas: distinct fractionation paths in the east Serbian segment of the Balkan-Carpathian arc. Journal of Petrology, V. 54, p. 421-451.
Li, J. X., Qin, K. Zh., Li, G. M., Xiao, B., Chen, L. and Zhao, J. X., 2011- Post-collisional orebearingadakitic porphyries from Gangdese porphyry copper belt, southern Tibet: Melting of thickened juvenile arc lower crust. Lithos, V. 126, p. 265-277.
Magnien, A., Salahshurian, M., Ternet, Y., Berthiaux, A., Christmann, P., Fauvelet, E., Harrival, J. N., Teherani, R., Weecksteen, G., Andreieff, P., Hottin. A. M., Danesfaleh, M., Sajedi, T. and AlaviNaini, M.,1983- Geological map of Iran, Gonabad, Scale 1:250,000. Geological Survey of Iran, Tehran.
MalekzadeShafaroudi, A., Karimpour, M. H. and Golmohammadi, A., 2013- Zircon U-Pb geochronology and petrology of intrusive rocks in the C-North and Baghak districts, Sangan iron mine, NE Iran. Journal of Asian Earth Sciences, V. 64, p. 256-271.
Maniar, P. D. and Piccoli, P. M., 1989- Tectonic discrimination of granitoids. Geological Society of America Bulletin, V. 101, p. 635-643.
Martin, H., 1999- Adakitic magmas: modern analogous of Archeangranitoids. Lithos, V. 46, p. 411- 429.
Mazhari, N., MalekzadehShafaroudi, A., Ghaderi, M., Star Lackey, J., Lang Farmer, G. and Karimpour, M. H., 2017- Geochronological and geochemical characteristics of fractionated I-type granites associated with the skarn mineralization in the Sangan mining region, NE Iran. Ore Geology Reviews, V. 84, p. 116-133.
Middlemost, E. A. K., 1985- Magmas and Magmatic Rocks. Longman, London and NewYork.
MonazzamiBagherzadeh, R., Karimpour, M. H., Lang Farmer, G., Stern, C. R., Santos, J. F., Rahimi, B. and HeidarianShahri, M. R., 2015- U-Pb zircon geochronology, petrochemical and Sr-Nd isotopic characteristic of Late Neoproterozoicgranitoid of the Bornaward Complex (Bardaskan-NE Iran). Journal of Asian Earth Sciences, V. 111, p. 54-71.
Morata, D., Oliva, C., de la Cruz, R. and Suarez, M., 2005- The Bandurrias Gabbro; late Oligocene alkaline magmatism in the Patagonian Cordillera. Journal of South American Earth Sciences, V. 18, p. 147-162.
Nagudi, N., Koberl, C. and Kurat, G., 2003- Petrography and geochemistry of the Sigo granite, Uganda and implications for origin. Journal of African Earth Sciences, V. 36, p. 1-14.
Pearce, J. A. and Parkinson, I. J., 1993- Trace element models for mantle melting: application to volcanic arc petrogenesis. In: Prichard, H. M., Albaster, T., Harris, N. B. W., Neary, C. R. (Eds.), Magmatic Processes in Plate Tectonics, Geological Society of London Special Publication, V. 76, p. 373-403.
Pearce, J. A. and Stern, R. J., 2006- Origin of Back-Arc Basin Magmas: Trace Element and Isotope Perspectives, in Back-Arc Spreading Systems. In: Christie, D. M., Fisher, C. R., Lee, S.M., Givens, S., (Eds.), Geological, Biological, Chemical, and Physical Interactions. American Geophysical Union, Washington, D. C. 
Pearce, J. A., 1983- Role of the subcontinental lithosphere in magma genesis at active continental margins. In: Hawkesworth, C. J., Norry, N. J. (Eds.), Continental Basaltsand Mantle Xenoliths. Shiva, Cheshire, UK, 230-249.
Pearce, J. A., 1996- Sources and settings of granitic rocks- Episodes, V. 19, p. 120-125.
Pearce, J. A., 2008- Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust. Lithos, V. 100, p. 14-48.
Pearce, J. A., Harris, N. B. 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.
Plank, T., 2005- Constraints from thorium/lanthanum on sediment recycling at subduction zones and the evolution of the ontinents. Journal of Petrology, V. 46, p. 921-944.
Ramezani, J. and Tucker, R. D., 2003- The Saghand region, Central Iran: U-Pbgechronology, petrogenesis and implications for Gondwana tectonics. American Journal of Science, V. 303, p. 622-665.
Roberts, M. P. and Clemens, J. D., 1993- Origin of high-potassium, calc-alkaline, I-type granitoids. Geology, V. 21, p. 825-828.
Rollinson, H., 1993- Using geochemical data: evaluation, presentation, interpretation. Singapore. Longman Singapore Publishers Ltd., p. 1-351.
Rudnick, R. L. and Gao, S., 2003- Composition of the continental crust. In: Rudnick, R. L., (Eds.), The crust, treatise in geochemistry, Elsevier-Pergamon, Oxford, V. 3, p. 1-64.
Rutter, J. M. and Wyllie, P., 1988- Melting of vapour-absent tonalite at 10 kbar to simulate dehydration-melting in the deep crust.Nature, V. 331, p. 159-160
Saunders, A. D., Tarney, J. and Weaver S. D., 1980- Transverse geochemical variations across the Antarctic Peninsula: implication for the genesis of calc-alkaline magmas.Earth and Planetary Science Letters, V. 46, p. 344-360.
ShafaiiMoghadam, H., Li, X. H., Ling, X. X., Santos, J. F., Stern, R. J., Li, Q. L. and Ghorbani, G., 2015- Eocene Kashmargranitoids (NE Iran): petrogenetic constraints from U-Pb zircon geochronology and isotope geochemistry. Lithos, V. 216-217, p. 118-135.
Stolz, A. J., Jochum, K. P., Spettel, B. and Hofmann, A. W., 1996- Fluid and melt related enrichment in thesub arc mantle: evidence from Nb/Ta variations in island arc basalts. Geology, V. 24, p. 587-590.
Sun, S. S. and McDonough, W. F., 1989- Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. Geological Society, London, Special Publications, V. 42, p. 313-345.
Taylor, S. R. and McLennan, S. M., 1995- The geochemical evolution of the continental crust. Reviews of Geophysics, V. 33, p. 241-265.
Ternet, Y., Guillou, Y., Maurizot, P., Berthiaux, A., Weecksteen, G., Hottin. A. M., Andreieff, P., Ancelin, J., Danesfaleh, M., Sajedi, T. and AlaviNaini, M., 1980a- Geological map of Iran, Khaf, Scale 1:100,000. Geological Survey of Iran, Tehran.
Ternet, Y., Salahshurian, M., Magnien, A., Weecksteen, G., Berthiaux, A., Hottin. A. M., Andreieff, P., Ancelin, J., Danesfaleh, M., Sajedi, T. and AlaviNaini, M., 1980b- Geological map of Iran, Roshtekhar, Scale 1:100,000. Geological Survey of Iran, Tehran.
Thieblemont, D. and Tegyey, M., 1994- Une discrimination geochimique des rochesdifferencieestemoin de la diversitedorigineet de situation tectonique des magmas calco-alcalins. C.R. Acad Sciences Paris, V. 319, p. 87-94.
Thuy, N. T. B., Satir, M., Siebel, W., Vennemann, T. and Long, T. V., 2004- Geochemical and isotopic constrains on the petrogenesis of granitoids from the Dalat zone, southern Vietnam. Journal of Asian Earth Sciences, V. 23, p. 467-482.
Turner, S., Bourdon, B., Hawkesworth, C. and Evans, P., 2000- 226Ra-230Th evidence for multiple dehydration events, rapid melt ascent and the time scales of differentiation beneath the Tonga-Kermadec island arc. Earth and Planetary Science Letters, V. 179, p. 581-593.
Walker, J. A., Patino, L. C., Carr, M. J. and Feigenson, M. D., 2001- Slab control over HFSE depletions in Central Nicaragua. Earth and Planetary Science Letters, V. 192, p. 533-543.
Wang, Q., Wyman, D.A., Xu, J., Dong, Y., Vasconcelos, P.M., Pearson, N., Wan, Y., Dong,H., Li, C., Yu, Y., Zhu, T., Feng, X., Zhang, Q., Zi, F. and Chu, Z., 2008- Eocene melting of subducting continental crust and early uplifting of central Tibet: evidence from central-western Qiangtang high-K calc-alkaline andesites, dacites and rhyolites. Earth Planet. Sci. Lett. 272, 158–171.
Weaver, B. L. and Tarney, J., 1984- Empirical approach to estimating the composition of the continental crust. Nature, V. 310, p. 575-577.
Whalen, J. B., Percival, J. A., McNicoll, V. J. and Longstaffe, F. G., 2004- Geochemical and isotopic (Nd-O) evidence bearing on the origin of late-to post-orogenic high-K granitoid rocks in the Western Superior Province: implication for late Archeantectonomagmatic processes. Precambrian Research, V. 132, p. 303-326.
Whitney, D. L. and Evans, B. W., 2010- Abbreviations for names of rock-forming minerals. American Mineralogist, V. 95, p. 185-187.
Wilson, M., 1989- Igneous petrogenesis: A global tectonic approach. Unwin Hyman, London, 466p.
Zhang, Zh. Y., Du, Y. S., Teng, Ch. Y., Zhang, J. and Pang, Zh. Sh., 2014- Petrogenesis, geochronology, and tectonic significance of granitoids in the Tongshan intrusion, Anhui Province, Middle-Lower Yangtze River Valley, eastern China. Journal of Asian Earth Sciences, V. 79, p. 792-809.
Zhao, Z. F., Zheng, Y. F., Wei, C. S. and Wu, Y. B., 2007- Post-collisional granitoids from the Dabieorogen in China: Zircon U-Pb age, element and O isotope evidence for recycling of subducted continental crust. Lithos, V. 93, p. 248-272.