نشریه علوم زمین خوارزمی

نشریه علوم زمین خوارزمی

دما-فشارسنجی و جایگاه تکتونیکی سنگ های دگرگونی ملانژ افیولیتی جنوب دهشیر (جنوب‌باختری یزد)

نویسندگان
1 دانشگاه بین لمللی امام خمینی(ره)، دانشکده علوم پایه، گروه زمین شناسی،
2 دانشگاه بین المللی امام خمینی(ره)، دانشکده علوم پایه، گروه زمین شناسی،
3 دانشگاه تهران، پردیس علوم، دانشکدۀ زمین شناسی
چکیده
ملانژ افیولیتی جنوب دهشیر بخشی از نوار افیولیتی نائین-بافت است. همراه با توالی پوسته­ای و گوشته­ای افیولیت­های جنوب دهشیر، بلوک­هایی از سنگ­های دگرگونی متشکل از آمفیبولیت، پیروکسن-اپیدوت­آمفیبولیت لایه­بندی­دار، گارنت-پیروکسن آمفیبولیت، گارنت-آمفیبول­گنیس و گارنت-اپیدوت­هورنبلندیت برونزد دارند. نتایج دما-فشارسنجی سه نمونه گارنت-پیروکسن آمفیبولیت، گارنت-آمفیبول­گنیس و گارنت-­اپیدوت­هورنبلندیت با یک‌دیگر هم­خوانی داشته و نشان­دهندۀ میانگین دما و فشار 664 درجۀ سانتی­گراد و 8/8 کیلوبار است. شرایط دما و فشار سنگ­های دگرگونی ملانژ افیولیتی جنوب دهشیر با شرایط پهنه­های دگرگونی قاعده­ای دمای بالای سایر زمین­درزهای افیولیتی دنیا مطابقت نشان می­دهد. رابطۀ مکانی نزدیک بین سنگ­های دگرگونی بررسی شده با افیولیت­های هم­جوار، شرایط دما-فشار دگرگونی و شیمی سنگ کل بیان‌گر آن است که این سنگ­ها معرف لیتوسفر اقیانوسی بالای پهنه فرورانش هستند که از رویداد دگرگونی قاعده­ای در جای‌گاه شروع فرورانش، نشأت گرفته­اند.





کلیدواژه‌ها

عنوان مقاله English

Thermobarometry and Tectonic Setting of Metamorphic Rocks from Ophiolitic Mélange of South Dehshir (SW Yazd)

نویسندگان English

Khadijeh heidari 1
mohsen nasrabady 2
reza nozaem 3
1 Geology Department, Imam Khomeini International University, Qazvin
2 Geology Department, Imam Khomeini International University, Qazvin
3 School of Geology, Faculty of Science, University of Tehran
چکیده English

Ophiolitic mélange of south Dehshir is a slice of Nain-Baft ophiolitic belt. Blocks of metamorphic rocks that consist of amphibolite, banded Px-Ep amphibolite, Grt-Px amphibolite, Grt-Am gneiss and Grt-Ep hornblendite are cropped out along with crustal and mantle sequence of ophiolites from south Dehshir. Thermoberometry results of three samples of Grt-Px amphibolite, Grt-Am gneiss and Grt-Ep hornblendite are compatible and indicating an average temperature and pressure of 664°C and 8.8 kb, respectively. PT conditions of metamorphic rocks of south Dehshir ophiolitic mélange are in accordance with the conditions of those from the other worldwide ophiolitic sutures. Intimate spatial relation between investigated metamorphic rocks and adjoining ophiolites, PT conditions of metamorphism and whole rock chemistry indicate that these rocks representing oceanic lithosphere of suprasubduction zone and have derived from sole metamorphism event in the subduction initiation setting.

کلیدواژه‌ها English

Sole metamorphism
thermobarometry
Subduction initiation
Dehshir
[1] Jamieson, R. A., "PT paths from high temperature shear zones beneath ophiolites", Journal of Metamorphic Geology 4 (1986) 3–22.
[2] Agard, P., Searle, M. P., Alsop, G. I. and Dubacq, B., "Crustal stacking and expulsion tectonics during continental subduction: P–T deformation constraints from Oman", Tectonics 29 (2010) 1–19.
[3] Searle, M. P. and Cox, J. S., "Tectonic setting, origin and obduction of the Oman ophiolite", Geological Society of America Bulletin 111 (1999) 104–122.
[4] Cowan, R. J., Searle, M. P., Waters, D. J., "Structure of the metamorphic sole to the Oman ophiolite, Sumeini Window and Wadi Tayyin: implications for ophiolite obduction processes", GSL Spec. Publ. 392 (2014) 155–175.
[5] Rioux, M., Garber, J., Bauer, A., Bowring, S., Searle, M. P., Kelemen, P., Hacker, B., "Synchronous formation of the metamorphic sole and igneous crust of the Semail ophiolite: New constraints on the tectonic evolution during ophiolite formation from high-precision U–Pb zircon geochronology", Earth and Planetary Science Letters 451 (2016) 185–195.
[6] Guilmette, C., Matthijs A. Smit, M. A., van Hinsbergen, D. J. J., Gürer, D., Corfu, F., Charette, B., Maffione, M., Rabeau, O., Savard, D., "Forced subduction initiation recorded in the sole and crust of the Semail Ophiolite of Oman", Nature Geoscience (2018) https://doi.org/10.1038/s41561-018-0209-2.
[7] Brandelik, A., "CALCMIN - an EXCEL (TM) Visual Basic application for calculating mineral structural formulae from electron microprobe analyses", Computers and Geosciences 35 (2009) 1540-1551.
[8] Shafahi‌i Moghadam, H., Stern, R. J., Late cretaceous forearc ophiolities of Iran", Island Arc 20 (2011) 1-4.
[9] Sabzehei M., "The Geological Map of Dehshir, 1:100000 Series: Tehran, Iran, Geological Survey of Iran", Sheet 6752, scale 1:100000 (1997).
[10] Berberian, M., King, G. C. P., "Towards a paleogeography and tectonic evolution of Iran", Canadian Journal of Earth Science 18 (1981) 210–265.
[11] Stampfli, G. M., Borel, G. D., "The TRANSMED transects in space and time: Constraints on the paleo tectonic evolution of the Mediterranean domain. In: Cavazza, W., Roure, F., Spakman, W., Stampfli, G. M., Ziegler, P., (eds). The TRANSMED Atlas: The Mediterranean Region from Crust to Mantle", Springer Verlag, (2004) 53-80.
[12] Ghasemi, A., Talbot, C. J., "A new tectonic scenario for the Sanandaj–Sirjan Zone (Iran)", Journal of Asian Earth Science 26 (2006) 683–693.
[13] Bagheri S., Stampfli G. M., "The Anarak, Jandaq and Posht-e-Badam metamorphic complex in central Iran: New geological data, relationships and tectonic implications", Tectonophysics 451 (2008) 123-155.
[14] Shafaii Moghadam, H., Whitechurch, H., Rahgoshay, M., Monsef, I., "Significance of Nain-Baft ophiolitic belt (Iran): short-lived, transtensional Cretaceous back-arc oceanic basins over the Tethyan subduction zone", Comp. Rendus Geosci. 341 (2009) 1016–1028.
[15] Agard, P., Omrani, J., Jolivet, L., Whitechurch, H., Vrielynck, B., Spakman, W., Wortel, R., "Zagros orogeny: a subduction-dominated process", Geol. Mag.148 (2011) 692–725.
[16] Hassanzadeh, J., Wernicke, B. P., "The Neotethyan Sanandaj-Sirjan zone of Iran as an archetype for passive margin-arc transitions", Tectonics 35 (2016) 586–621.
[17] Shafaii Moghadam, H., Stern, R.J., Rahgoshay, M., "The Dehshir ophiolite (central Iran): Geochemical constraints on the origin and evolution of the Inner Zagros ophiolite belt", Geological Society of American Bulletin 122 (2010) 1516–1547.
[20] Frey, M., De Capitani, C. and Liou, J. G., "A new petrogenetic grid for low-grade metabasites", Journal of Metamorphic Geology 9 (1991) 479-509.
[21] Hollocher, K., "A pictorial guid to metamorphic rocks in the field", Taylor & Francis Group (2014) London, UK.
[22] Haggerty, S. E., "Oxide textures: A mini-atlas", In Mineralogical Society of America Reviews in Mineralogy 25 (1991) 129-219.
[23] Whitney, D. L. and Evans, B. W., "Abbreviations for names of rock-forming minerals", American Mineralogist 95 (2010) 185–187.
[24] Hawthorne, F. C., Oberti, R. E., Harlow, G. V., Maresch, W. F., Martin, R. C., Schumacher, J. D., Welch M., "Nomenclature of the amphibole supergroup", American Mineralogist 97 (2012) 2031–2048.
[25] Deer, W. A., Howie, R. A. and Zussman, J. "An introduction to the rock forming minerals", Longman, London, (1996) 528.
[26] Morimoto, N. "Nomenclature of pyroxenes", American Mineralogist 73 (1988) 1123-1133.
[27] Schumacher, J. C., "Appendix 2. The estimation of the proportion of ferriciron in the electron-microprobe analysis of amphiboles". In: Leake, B. E., et al. (Eds. Nomenclature of Amphiboles, Canadian Mineralogist 35 (1997) 238–246.
[28] Guidotti, C.V., and Dyar, M. D., "Ferric iron in metamorphic biotite and its petrologic and crystallochemical implications", American Mineralogist 76 (1991) 161-175.
[29] Dyar, M. D., Guidotti, C. V., Harper, G. D., McKibben, M. A., Saccocia, P. J., "Controls on ferric iron in chlorite", Geological of American Society, Abstr. Prog. 24 (1992) 130.
[30] Dyar, M. D.; McGuire, A. V., "Redox equilibria and crystal chemistry of coexisting minerals from spinel lherzolite mantle xenoliths", American Mineralogist 74 (1989) 969–980.
[31] Powell, R. and Holland T. J. B., "On thermobarometry", Journal of Metamorphic Geology 26 (2008) 155-179.
[32] Krogh Ravna, E., "Distribution of Fe2+ and Mg between coexisting garnet and hornblende in synthetic and natural systems: an empirical calibration of the garnet–hornblende Fe-Mg geothermometer", Lithos 53 (2000a) 305-321.
[33] Nakamura, D., "A new formulation of garnet–clinopyroxene geothermometer based on accumulation and statistical analysis of a large experimental data set", Journal of Metamorphic Geology 27 (2009) 675-689.
[34] Krogh Ravna, E., "The garnet-clinopyroxene Fe2+- Mg geothermometer: an update calibration", Journal of Metamorphic Geology 18 (2000b) 211-219.
[35] Ganguly, J., Cheng, W., Tirone, M., "Thermodynamics of aluminosilicate garnet solid solution: new experimental data, an optimized model, and thermometric applications", Contributions to Mineralogy and Petrology 126 (1996) 137–151.
[36] Berman, R. G., Aranovich, L. Y., Pattison, D. R. M., "Reassessment of the garnet–clinopyroxene Fe–Mg exchange thermometer: II. Thermodynamic analysis", Contributions to Mineralogy and Petrology 119 (1995) 30–42.
[37] Ellis, D. J. and Green, D. H., "An experimental study of the effect of Ca upon garnet-clinopyroxene Fe-Mg exchange equlibria", Contributions to Mineralogy and Petrology 71 (1979) 13-22.
[38] Holland T., Blundy J., "Non-ideal interactions in calci amphiboles and their bearing on amphibole-plagioclase thermometry", Contributions to Mineralogy and Petrology 116 (1994) 47-433.
[39] Kohen, M. J. and Spear, F. S., "Two new geobarometers for garnet amphibolites with applications to southeastern Vermont", American Mineralogist 75 (1990) 89-96.
[40] Ernst, W. G. and Liu, J., "Experimental phase-equilibrium study of Al- and Ti-contents of calcic amphibole in MORB-A semiquantitative thermobarometer", American Mineralogist 83 (1998) 952-969.
[41] Wu, C. M., "Original calibration of a garnet geobarometer in metapelite", Minerals 9 (2019) 540; doi:10.3390 /min 9 090540.
[42] Goldman, D. S., Albee, A. L., "Correlation of Mg/Fe partitioning between garnet and biotite with 18O/16O partitioning between quartz and magnetite", American Journal of Science 277 (1977) 750–767.
[43] Lavrent’eva, I. V., Perchuk, L. L., "Experimental data on phase correspondence in the system biotite–garnet", Doklady Geoscience Section 260 (1981) 168– 171.
[44] Perchuk, L. L., Lavrent’eva, I. V., "Experimental investigation of exchange equilibria in the system cordierite–garnet–biotite", In: Saxena, S. K. (Ed.), Kinetics and Equilibrium in Mineral Reactions. Springer-Verlag, New York, (1983) 199–239.
[45] Bhattacharya, A., Mohanty, L., Maji, A., Sen, S. K., Raith, M., "Non-ideal mixing in the phlogopite–annite binary: constraints from experimental data on Mg–Fe partitioning and a reformulation of the biotite–garnet geothermometer", Contributions to Mineralogy and Petrology 111 (1992) 87– 93.
[46] Wu, C. M. and Chen, H. X., "Revised Ti-in-biotite geothermometer for ilmenite- or rutile-bearing crustal metapelites", Science Bulletin 60 (2015) 116-121.
[47] Liu, J. Bohlen, S. R. and Ernest, W. G., "Stability of hydrous phases in subducting oceanic crust", Earth and Planetary Science Letters 143 (1996) 161-171.
[48] Nagel, T. J., Hoffmann, E. and Münker, C., "Generation of Eoarchean tonalite-trondhjemite-granodiorite series from thickened mafic arc crust", Geology 40 (2012) 375-378.
[49] Pearce, J. A., "A users guide to basalt discrimination diagrams. In: Wyman, D. A. (eds) Trace Element Geochemistry of Volcanic Rocks: Applications for Massive Sulphide Exploration", Geological Association of Canada, 12 (1996) 79-113.
[50] Winchester, J. A. and Floyd, P. A., "Geochemical magma type discrimination: application to altered and metamorphosed igneous rocks", Earth and Planetary Science Letters 28 (1976) 459–469.
[51] Pearce, J. A. and Gale, G. H., Identification of ore- deposition environment from trace element geochemistry of assocciated igneous host rocks. Geological Society, Special Publlcation 7 (1977) 14-24.
[52] Shervais, J. W., "Ti-V plots and the petrogenesis of modern and ophiolitic lavas", Earth and Planetary Science Letters 59 (1982) 101-118.
[53] Pearce, J. A., "Trace element characteristics of lavas from destructive plate boundaries. In: Thorpe, R. S. (ed.) Andesites. Chichester", John Wiley, (1982) 525-547.
[54] Wood, D. A., "The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province" Earth and Planetary Science Letters 50 (1980) 11-30.
[55] Sun S. S., and McDonough W. F., "Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes, In: Saunders A. D., Norry M. J. (Eds.), Magmatism in Ocean Basins", Special Publications, Geological Society, London 42 (1989) 312-345.
[56] Kazmin, V. G. and Kulakov, V., "The geological map of Syria, 1:500000 (sheet Al-Latheqiyeh), Explanatory note, Technoexport" Nedra, Moscow (1968).
[57] DavoudZadeh, M., "Geology and petrography of the area north of Nain, Central Iran", Geological Survey of Iran. Rep. (1972) No.: 39.
[58] AlaviTehrani, N., "Geology and petrography in the ophiolite range NW of Sabzevar (Khorasan/Iran) with special regards to metamorphism and genetic relations in an ophiolite suite", Geological Survey of Iran, Rep. (1977) No.: 43.
[59] Nasrabady, M., Rossetti, F., Theye, T., Vignaroli, G., "Metamorphic history and geodynamic significance of the Early Cretaceous Sabzevar granulites (Sabzevar structural zone, NE Iran)", Solid Earth 3 (2011) 477–526.
[62] Agard, P., Yamato, P., Soret, M., Prigent, C., Guillot, S., Plunder, A., Dubacq, B., Chauvet, A., Monie, P., "Plate interface rheological switches during subduction infancy: control on slab penetration and metamorphic sole formation", Earth and Planetary Science Letter 451 (2016) 208–220.
[63] Wakabayashi, J., Dilek, Y., "What constitutes ‘emplacement’ of an ophiolite? Mechanisms and relationship to subduction initiation and formation of metamorphic soles, in Dilek, Y., Robinson, P. T., eds., Ophiolites in Earth History", Geological Society of London, Special Publications 218 (2010) 427–447.
[64] Wakabayashi, J., Ghatak, A., Basu, A. R., "Suprasubduction-zone ophiolite generation, emplacement, and initiation of subduction: A perspective from geochemistry, metamorphism, geochronology, and regional geology", Geological Society of America Bulletin 122 (2010) 1548–1568.
[65] van Hinsbergen, D. J. J., Peters, K., Maffione, M., Spakman, W., Guilmette, C., Thieulot, C., Plümper, O., Gürer, D., Brouwer, F. M., Aldanmaz, E., Kaymakcı, N., "Dynamics of intra-oceanic subduction initiation: 2. Suprasubduction zone ophiolite formation and metamorphic sole exhumation in context of absolute plate motions", Geochemistry Geophysics and Geosystem 16 (2015) 1771–1785.
[66] Plunder, A., Agard, P., Chopin, C., Soret, M., Okay, A. I., Whitechurch, H., "Metamorphic sole formation, emplacement and blueschist facies overprint: early subduction dynamics witnessed by western Turkey ophiolites", Terra Nova 28 (2016) 329-339.