Geochemistry of metapelitic rocks from the Garmichay Area, East Azerbaijan, NW Iran; protolith nature and whole rock control on metamorphic mineral assemblages

Document Type : Research Paper

Authors

1 Department of Earth Sciences, University of Tabriz, 51664, Tabriz

2 Department of Earth Sciences, University of Tabriz

3 Geoscience Department, University Brunei Darussalam, Tunkgu Link, Gadong BE 1410, Brunei Darussalam

4 Department of Geology, University of Gorgan

Abstract

The protoliths of metamorphosed argillaceous rocks from the Garmichay area in the East Azerbaijan province of NW Iran were clay-rich sediments of reworked nature, originating most likely from an andesite to andesite-basalt source and deposited in an active continental margin tectonic setting. The protoliths of the Garmichay metapelites experienced low to moderate chemical weathering. Andalusite, cordierite, biotite, and muscovite are produced due to metamorphism under low-pressure and medium-temperature conditions. Cordierite throughout the whole assemblages is altered to the pseudomorphs pinite. Some rock samples contain both andalusite and altered cordierite as porphyroblasts, whereas others contain only andalusite or altered cordierite. Pressure and temperature estimates indicate that pressure for metamorphism was in the range 1-2.5 kbar with temperature between 500-600°C. Major oxides abundance show similar values in all analyzed samples, while concentration of some minor elements, especially zinc, show meaningful differences in rocks with different metamorphic mineral assemblages. The variations in the abundance of these minor elements may have played important role in the control of the mineral assemblages present.

Keywords

Article Title [Persian]

زمین شیمی سنگهای رسی دگرگون در منطقه گرمی چای، آذربایجان شرقی، شمال غرب ایران- ماهیت سنگ مادر اولیه و کنترل شیمی سنگ کل بر مجموعه کانیهای دگرگونی

Authors [Persian]

  • محسن موذن 1
  • مهدی قادری 2
  • هادی عمرانی 4
1
2 گروه علوم زمین - دانشگاه تبریز
3
4 گروه زمین شناسی دانشگاه گرگان
Abstract [Persian]

سنگ مادر سنگها دگرگونی رسی منطقه گرمی چای در آذربایجان شرقی در شمال غرب ایران رسوبات غنی از رس با ماهیت فرسایش یافته بوده است که به احتمال زیاد از یک سنگ اولیه آندزیت تا آندزیت بازالت منشا گرفته و در یک محیط  تکتونیکی حاشیه فعال قاره ای رسوب کرده اند. سنگ مادر سنگهای دگرگونی گرمی چای قبل از دگرگونی هوازدگی شیمیایی ضعیف تا متوسطی را تحمل کردند. آندالوزیت، کردیریت، بیوتیت و موسکویت حاصل دگرگونی در شرایط فشار پایین و دمای متوسط  هستند. کردیریت در تمامی این سنگها به سودومورف پنیت تجزیه شده اند. برخی از نمونه های سنگی دارای هر دو کانی آندالوزیت و کردیریت هوازده به صورت درشت بلور هستند در حالیکه نمونه های دیگر حاوی تنها آندالوزیت و یا تنها کردیریت هوازده هستند. دما و فشار محاسبه شده برای دگرگونی نشان می دهد که محدوده فشاری 1 تا 5/2 کیلوبار و دما بین 500 تا 600 درجه سانتیگراد بوده است.  فراوانی اکسیدهای اصلی در تمامی نمونه های تجزیه شده مقادیر مشبهی نشان می دهند در حالیکه مقادیر برخی عناصر فرعی به ویژه روی تفاوت معنی داری بین نمونه ها ی با مجموعه کانی شناسی متفاوت نشان می دهند. تفادت مقادیر این عناصر فرعی می تواند نقش مهمی در مجموعه کانی شناسی سنگها ایفا کند.

Keywords [Persian]

  • سنگ رسی دگرگون
  • سنگ مادر
  • هوازدگی شیمیایی
  • دگرگونی
  • مجموعه کانی
  • شمال غرب ایران

References

Behruzi, A., Amini Azar, R., 1992. Geological map of Sarab, 1:100000, Geological Survey of Iran.
Berman, R.G., 1988. Internally-consistent thermodynamic data for minerals in the system Na2O-K2O-CaO-MgO-FeO-Fe2O3-Al2O3-SiO2-TiO2-H2O-CO2. Journal of Petrology, 29: 445–522.
Bertoldi, C., Proyer, A., Schonberg, D. G., Behrens, H., Dachs, E., 2004. Comprehensive chemical analyses of natural cordierites: implications for exchange Mechanisms. Lithos,78: 389-409.
Bucher, K., Grapes, R., 2011. Petrogenesis of metamorphic rocks. Springer-Verlag, 428 p.
Condie, K. C., 1993. Chemical composition and evolution of the upper continental crust: contrasting results from surface samples and shales. Chemical Geology, 104: 1–37.
Cox, R., Lowe, D. R., Cullers, R. L., 1995. The influence of sediment recycling and basement composition of evolution of mud rock geochemistry in the south western United States, Geochimica et Cosmochimica Acta, 59: 2919–2940.
Cullers, R.L., DiMarco, M.J., Lowe, D.R., Stone, J., 1993. Geochemistry of a silicified, felsic volcaniclastic suite from the early Archaean Panorama Formation, Pilbara Block, Western Australia: an evaluation of depositional and post-depositional processes with special emphasis on the rare-earth elements. Precambrian Research, 60:99–116.
de Capitani, C.,Brown, T. H., 1987. The computation of chemical equilibrium in complex systems containing non-ideal solutions. Geochimica et Cosmochimica Acta, 51: 2639–2652
Droop, G. T. R., Harte, B., 1995. The effect of Mn on the phase relations of medium-grade pelites: constraints from natural assemblages on petrogenetic grid topology, Journal of Petrology, 36: 1549-1578.
Eftekharnejad J (1981) Tectonic division of Iran with respect to sedimentary basins. Journal of Iranian Petroleum Society, 82:19–28 (in Persian)
Ewart, A., 1982. The mineralogy and petrology of Tertiary–Recent orogenic volcanic rocks: with special reference to the andesitic–basaltic compositional range, in Thorpe, R.S., ed., Andesites: Orogenic Andesites and Related Rocks: Chichester, U.K., John Wiley & Sons, p. 25–95.
Fedo, C.M., Nesbitt, H.W., Young, G.M., 1995. Unraveling the effects of potassium metasomatism in sedimentary rocks and paleosoils, with implications for paleoweathering conditions and provenance. Geology, 23: 921–924.
Hallberg J. A., 1984. A geochemical aid to igneous rock identification in deeply weathered terrain, Journal of Geochemical Exploration, 20: 1-8.
Harnois, L., 1988. The CIW index: A new chemical index of weathering.  Sedimentary Geology, 55: 319–322.
Hassanzadeh, J., Stockli, D. F., Horton, B. K., Axen, G. J., Stockli, L. D., Grove, M., Schmidt, A.K., Walker, J. D., 2008. U-Pb zircon geochronology of late Neoproterozoic–Early Cambrian granitoids in Iran: Implications for paleogeography, magmatism, and exhumation history of Iranian basement. Tectonophysics, 451: 71-96.
Heier, K. S.,Billings, G. K.,1970.Rubidium. Handbook of Geochemistry (Wedepohl, K. H., ed.), 37B1–37N1, Springer, Berlin.
Herron M. M., 1988. Geochemical classification of terrigenous sands and shales from core or log data, Journal of Sedimentary Petrology, 58:820-829.
Jamshidi Badr, M., Collins, A. S., Masoudi, F., 2013. The U-Pb age, geochemistry and tectonic significance of granitoids in the Soursat Complex, Northwest Iran, Turkish Journal of Earth Sciences, 22 (1):1-31.
Li, Y.H.,2000. A Compendium of Geochemistry: Princeton, New Jersey, Princeton University Press, 475p.
Long, X., Sun, M., Yuan, C., Xiao, W. and Cai, K., 2008. Early Paleozoic sedimentary record of the Chinese Altai; Implications for its tectonic evolution, Sedimentary Geology, 208:88100.
Mahar, E. M., Baker, J. M., Powell, R., Holland, T. J. B., Howell, N.,1997.The effect of Mn on mineral stability in metapelites, Journal of Metamorphic Geology, 15:223-238.
Mason, B. and Moore, C. B.,1982. Principle of Geochemistry. John Willey and Sons. Fourth Ed.344pp.
McLennan, S. M., Taylor, S. R..1980. Th and U in sedimentary rocks: crustal evolution and sedimentary recycling. Nature, 285:621–624.
McLennan, S. M., Hemming, S., McDaniel, D. K., Hanson, G. N.,1993.Geochemical approaches to sedimentation, provenance and tectonics, In Johnsson, M.J., and Basu, A., eds., Processes Controlling the Composition of Clastic Sediments: Geological Society of America, Special Paper, 284: 21–40.
Moazzen, M. Hajialioghli, R., Möller, A., Droop, G. T. R., Oberhänsli, R., Altenberger, U., Jahangiri, A., 2013. Oligocene partial melting in the Takab metamorphic complex, NW Iran; Evidence from in situe U-Pb geochronology. Journal of Sciences Islamic Republic of Iran, 26(2): 153-161.
Nesbitt, H.W., Young, G. M., 1982. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature, 199: 715–717.
Nichols, G.T., Berry, R.F., Green, D. H., 1992. Internally consistent gahnitic spinel-cordierite-garnet equilibria in the FMASHZn system: geothermobarometry and applications, Contributions to Mineralogy and  Petrology, 111:362-377.
Pearce, J. A., Cann, J. R., 1973. Tectonic setting of basic volcanic rocks determined using trace element analyses, Earth and Planetary Science Letters, 19: 290–300.
Pinto, L., Herail, G., Moine, B., Fonton, F., Charrier, R., Dupre, B., 2004.Using geochemistry to establish the igneous provenances of the Neogene continental sedimentary rocks in the Central Depression and Altiplano, Central Andes, Sedimentary Geology, 166: 157-183.
Potter, P. E., Maynard, J. B., Depetris, P. J., 2005. Mud and Mudstones: Introduction and Overview: Heidelberg, Springer-Verlag, 297 pp.
Puchelt, H., 1972. Barium. Handbook of Geochemistry (Wedepohl, K. H. et al., eds.), 56B1–56O2, Springer, Berlin.
Rudnick, R. L., Gao, S., 2003. Composition of the continental crust. Treatise on Geochemistry, Volume 3. Elsevier, P. 1-64.
Roser, B. P., Korsch, R. J., 1988. Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data. Chemical Geology, 67:119–139.
Saki, A., 2010. Proto-Tethyan remnants in northwest Iran: geochemistry of the gneisses and metapelitic rocks. Gondwana Research,17:704–714.
Saki, A., Moazzen, M., Oberhänsli, R., 2012. Mineral chemistry and thermobarometry of the staurolite-chloritoid schists from Poshtuk, NW Iran. Geological Magazine, 149: 1077-1088.
Shafaii Moghadam, H., Li, X. H., Stern, R. J., Ghorbani, G., Bakhshizad, F., 2016. ZirconU–Pb       ages and Hf–O isotopic composition of migmatites from the Zanjan–Takab complex, NW Iran: Constraints on partial melting of metasediments. Lithos, 240: 38-48.
Stöklin, J.,1968. Structural history and tectonics of Iran; a review. American Association of Petroleum Geology Bulletin, 52:6-7.
Taylor, S. R., McLennan, S. M.,1985. The Continental Crust: Its Composition and Evolution. Blackwell, Oxford, 312 pp.
Van Kranendonk, M. J.,2006. Volcanic degassing, hydrothermal circulation and the flourishing of early life on Earth: a review of the evidence from c. 3490–3240 Ma rocks of the Pilbara Supergroup, Pilbara Craton, Western Australia. Earth Science Reviews, 74: 197–240.
Wei, C. J., Powell, R., Clarke, G. L.,2004. Calculated phase equilibria forlow- and medium-pressure metapelites in the KFMASH and KMnFMASH systems. Journal of Metamorphic Geology, 22:495-508.
Werner, C. D.,1987. Saxonian granulites-igneous or lithoigneous: a contribution to the geochemical diagnosis of the original rock in high metamorphic complexes. Zfl Mitteilungen, 13: 221-250.
Whitney, D. L., Evans, B. W., 2010. Abbreviations for names of rock-forming minerals. American Mineralogist, 95: 185-187.
Winchester, J. A., Floyd, P. A., 1977. Geochemical discrimination of different magma series and their differentiation products using immobile. Chemical Geology, 20: 325–343.
Wronkiewicz, D.J., Condie, K. C., 1987. Geochemistry of Archean shales from the Witwatersrand Supergroup, South Archean shales from the Witwatersrand Supergroup, South Africa: source-area weathering and provenance. Geochimica et Cosmochimica Acta, 51: 240-2416.
Zang, L., Sun, M., Wang, S.,Yu, X., 1998. The composition of shales from the Ordos basin, China: effects of source weathering and diagenesis, Sedimentary Geology,116: 129-141.
Geopersia
Volume 6, Issue 1 - Serial Number 22287825
Winter and Spring
March 2016
Pages 1-18

Files

History

  • Receive Date: 23 May 2015
  • Revise Date: 25 May 2016
  • Accept Date: 29 June 2016

Share

How to cite

Statistics