Document Type : Original Research Paper

Authors

1 Assistant Professor, Department of Geology, Faculty of Science, University of Isfahan, Isfahan, Iran

2 M.Sc. Student, Department of Geology, Faculty of Science, University of Isfahan, Isfahan, Iran

3 Professor, Department of Mining, Faculty of Engineering, University of Kurdestan, Sanandaj, Iran

Abstract

The Dorojin granitoid at the northeastern Isfahan is located in the central Urumieh-Dokhtar zone and within the volcano-sedimentary complex. The Dorojin iron deposit is the one of the several ore deposits that Dorojin granitoid body is caused in its surrounding rocks. According to microscopic evidences, mineral assemblage of wollastonite, garnet, pyroxene (diopside), amphibole, epidote, feldspar, calcite and quartz, Dorojin deposit attributed to the class of calcic skarns that occur during two stages progressive and regressive. Based on electron microprobe analysis, some garnets are andradite (An92-97Gr1-5) in core and andradite-grossular (An53-66Gr30-41Sp2-4) in rim. In the beginning, andradite fluid inclusions with temperature range from 369˚ to 444˚C and salinity range from 11.22 to 12.96 wt.% NaCl eqv., originate from magmatic fluids, while with change in the acidity condition of environment and the opening of system, grandite, epidote and calcite fluids with a temperature between 221˚ and 305˚C and salinity between 0.4 and 10.11 wt.% NaCl eqv., are dominated by mixing and dilution of early magmatic fluids with meteorite waters. Sr isotopic ratio of garnet vary between 0.70760 and 0.70805, suggesting that prominent role of the magmatic fluids for the formation of andraditic garnet.

Keywords

Main Subjects

References
Beygi, S., Nadimi, A. R. and Safaei, H., 2016- Tectonic history of seismogenic fault structures in Central Iran. Journal of geosciences 61: 127-144.
Bodnar, R. J. and Vityk, M. O., 1994- Interpretation of microthermometric data for H2O-NaCl fluid inclusions. In: De Vivo, B., Frezzotti, M. L. (Eds.), Fluid Inclusions in Minerals, Methods and Applications. Virginia Tech, Blacksburg: 117–130.
Bowman, J. R., 1998- Stable-isotope systematics of skarns, Mineralogical Association of Canada Short Course 26: 99–145.
Burt, D. M., 1977- Mineralogy and petrology of skarn deposits. Rendiconti Societa Italiana di Mineralogia e Petrologia 33(2): 859-873.
Casillas, R., Demény, A., Nagy, G., Ahijado, A. and Fernández, C., 2011- Metacarbonatites in the Basal Complex of Fuerteventura (Canary Islands). The role of fluid/rock interactions during contact metamorphism and anataxis. Lithos 125: 503–520.
Chiu, H. Y., Chung, S. L., Zarrinkoub, M. H., Mohammadi, S. S., Khatib, M. M. and Iizuka, Y., 2013- Zircon U-Pb age constraints from Iran on the magmatic evolution related to Neotethyan subduction and Zagros orogeny. Lithos 162–163: 70–87.
Christensen, J. N., Rosenfeld, J. L. and De Paolo, D. J., 1989- Rates of tectonometamorphic processes from rubidium and strontium isotopes in garnet. Science 244: 1465-1469.
Ciobanu, C. L. and Cook, N. J., 2004- Skarn textures and a case study: the Ocna de Fier-Dognecea orefield, Banat, Romania. Ore Geology Reviews 24: 315-370.
Crawford, M. L., 1981- Phase equilibria in aqueous fluid inclusions. Short course in fluid inclusions: applications to petrology 6: 75–100. (in Persian).
Demir, Y., Uysal, I., Kandemir, R. and Jauss, A., 2017- Geochemistry, fluid inclusion and stable isotope constrants (C and O) of the Sivrikaya Fe-skarn mineralization (Rize, NE Turkey). Ore geology reviews 91: 153-172.
Einaudi, M. T. and Burt, D. M., 1982- Introduction-terminology, classification and composition of skarn deposits. Economic Geology 77: 745-754.
Einaudi, M. T., 1982- Descriptions of skarns associated with porphyry copper plutons, In: S.R. Titley (Editor), Advances in geology of porphyry copper deposits, southwestern North America. University of Arizona Press, Tucson: 1592-1606.
Einaudi, M. T., Meinert, L. D. and Newberry, R. J., 1981- Skarn deposits, Economic Geology 75: 317-391.
Gaspar, M., Knaack, C., Meinert, L. D. and Moretti, R., 2008- REE in skarn systems: A LA-ICP-MS study of garnets from the Crown Jewel gold deposit, Geochimica et Cosmochimica Acta 72 (1): 185–205.
Golmohammadi, A., Karimpour, M. H. and Malekzadeh, A., 2015- Alteration, mineralization, and radiometric ages of the source pluton at the Sangan iron skarn deposit, northeastern Iran. Ore Geology Reviews 65: 545–563.
Hodell, D. A., Kamenov, G. D., Hathorne, E. C. and Zachos, J. C., 2007- Variations in the strontium isotope composition of seawater during the Paleocene and early Eocene from ODP Leg 208 (Walvis Ridge). Geochemistry, Geophysics Geosystems: 1-15. DOI:10.1029/2007GC001607.
Idrus, A., Kolb, J., Meyer, F. M., Arif, J., Setyandhaka, D. and Kepli, S., 2009- A preliminary study on skarn-related calc-silicate rocks associated with the Batu Hijau porphyry copper-gold deposit, Sumbawa Island, Indonesia. Resource Geology 59: 295-306.
Kesler, S. E., 2005- Ore-forming fluids, Elements 1(1): 13-18.
Kodera, P., Rankin, A. H. and Lexa, J., 1998- Evolution of fluids responsible for iron skarn mineralisation: an example from the Vyhne-Klokoc deposit, Western Carpathians, Slovakia. Mineralogy and Petrology 64: 119-147.
Kohn, M. J., 2013- Geochemical zoning in metamorphic minerals. In: Treatise on geochemistry. 3. The crust (ed. Rudnick, R.), pp. 229–261. Elsevier, Amsterdam.
Lentz, D. R. and Suzuki, K., 2000- A low F pegmatite-related skarn from the southwestern Grenville Province, Ontario, Canada: phase equilibria and petrogenetic implications. Economic Geology 95: 1319–1337.
Lentz, D. R., Walker, J. and Stirling, J., 1995- Millstream Cu-Fe skarn deposit: an example of a Cu mineralized magnetite-rich skarn system in northern New Brunswick. Exploration and mining geology 4: 15-31.
McArthur, J. M., Howarth. R. J. and Bailey, T. R., 2001- Strontium Isotope Stratigraphy: LOWESS Version 3: Best Fit to the Marine Sr-Isotope Curve for 0–509 Ma and Accompanying Look-up Table for Deriving Numerical Age. Journal of geology 109: 155-170.
Meinert, L. D., Hedenquist, J. W., Satoh, H. and Matsuhisa, Y., 2003- Formation of anhydrous and hydrous skarn in Cu-Au ore deposits by magmatic fluids. Economic Geology 98: 147-156.
Morimoto, N., Fabrise, J., Ferguson, A., Ginzburg, I. V., Ross, M., Seifert, F. A., Zussman, J., Aoki, K. and Gottardi, G., 1988- Nomenclature of pyroxene, Mineralogical Magazine 52: 535-555.
Muller, D. and Groves, D. I., 2016- Potassic Igneous Rocks and Associated Gold-Copper Mineralization. fourth ed. Springer-Verlag, Berlin-Heidelberg-New York: 311 p.
Nabatian, G., Rastad, E., Neubauer, F., Honarmand, M. and Ghaderi, M., 2015- Iron and Fe-Mn mineralisation in Iran: implications for Tethyan metallogeny. Australian Journal of Earth Sciences 62: 211-241.
Palmer, M. R. and Edmond, J. M., 1989- The strontium isotope budget of modern ocean, Earth planet. Sci. Lett., 92: 11-26.
Park, C., Choi, W., Kim, H., Park, M. H., Kang, I. M., Lee, H. S. and Song, Y., 2017- Oscillatory zoning in skarn garnet: Implications for tungsten ore exploration, Ore geology reviews 89: 1006-1018.
Perkins, E. H., Brown, T. H. and Berman, R.G., 1986- PTX-SYSTEM: three programs for calculation of pressure– temperature– composition phase diagrams. Computers and Geoscience 12(6): 749–755.
Pons, J. M., Franchini, M., Meinert, L., Recio, C. and Etcheverry, R., 2009- Iron skarns of the vegas Peladas District, Mendoza, Argentina. Economic Geology 104: 157-184.
Radfar, J. and Amini Chehragh, M. R., 1999- Ardestan Geological map quadrangle, scale 1:100000, Geological Survey of Iran, Tehran.
Sarjoughian, F. and Kananian, A., 2017-  Zircon U-Pb geochronology and emplacement history of intrusive rocks in the Ardestan section, central Iran. Geologica Acta 15 (1): 25-36.
Sarjoughian, F., Lentz, D., Kananian, A., Ao, S. and Xiao, W., 2017- Geochemical and isotopic constraints on the role of juvenile crust and magma mixing in the UDMA magmatism, Iran: Evidence from mafic microgranular enclaves and cogenetic granitoids in the Zafarghand igneous complex. International Journal of Earth Sciences. https://doi. org/10.1007/s00531‐017‐1548‐8.
Spear, F. S., 1995- Metamorphic Phase Equilibria and PressureTemperature-Time Paths. Mineralogical Society of America, Washington, D.C.
Vlasova, D. V., Podlesskiy, K. V., Kudrya, P. F., Boronikhin, V. A. and Muravitskaya, G. N., 1985- Zoning in garnets from skarn deposits. International Geology Review 27: 465-482. DOI: 10.1080/ 00206818509466434.
Whitney, D. L. and Evans, B. W., 2010- Abbreviations for names of rock-forming minerals. American mineralogist 95(1): 185-187.
Whitney, J. A., Hemley, J. J. and Simon, F. O., 1985- The concentration of iron in chloride solution equilibrated with synthetic granitic compositions: The sulfur-free composition. Economic Geology 80: 444-460.
Wilkinson, J. J., 2001- Fluid inclusions in hydrothermal ore deposits, Lithos 55(1): 229-272.
Williams- Jones, A. E., Samson, I. M., Ault, K. M., Gagnon, J. E. and Fryer, B. J., 2010- The genesis of distal zinc skarns: evidence from the Mochito deposit, Honduras. Economic Geology 105: 1411-1440.
Zhai, D. G., Liu, J. J., Zhang, H. Y., Wang, J. P., Su, L., Yang, X. A. and Wu, S. H., 2014- Origin of oscillatory zoned garnets from the Xieertala Fe–Zn skarn deposit, northern China: in situ LA–ICP-MS evidence. Lithos 190: 279-291.