Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Mineralization of chromite and ilmenite in Kurdistan ophiolite: An approach to determine the geotectonic setting

Document Type : Original Research Paper

Authors
Mohammad Ali Rajabzadeh 1
Mohammad Amini 2
1 Department of Earth Sciences, Faculty of Science, Shiraz University, Shiraz, Iran
2 School of Geology, Faculty of Science, University of Tehran, Tehran, Iran
10.22071/gsj.2022.308944.1941
Abstract
This is the first report on the presence of podiform chromititeLenses associated with the Marivan ophiolite. These ore deposits with granular massive fabric are hosted by dunite and harzburgite occurred in south Marivan city. Chemistry of chromian spinel in the chromite Lenses indicated that Cr#  for two ore occurrences is high (0.85) with very low TiO2, but for the other ore occurrence is lower (0.67) with higher TiO2 (0.05). The finding shows that the chromite ore Lenses and consequently their host ophiolite were developed in two different geotectonical settings. Geochemical data indicated that some of the studied ore deposits occurred during the opening of oceanic crust in a Mid Oceanic Ridge setting from a tholeiitic magma while the others were fractionated form a boninitic melt in a Supra Subduction Zone. Formation of these ore Lenses and the host rocks occurred in response to the very fast divergence and then convergence of Neo-Tethys oceanic crust. A wide range of gabbros including coarse-grained gabbro, melagabbro and microgabbro host ilmenite, magnetite and titanite in three regions at the northwest of Kamyaran (Yakhtekhan village), the east of Sarvabad (Mianeh village) and the south of Marivan (Dragashikhan-Vyseh villages). Ilmenite is found in all the three regions, but magnetite and titanite are only found in the east of Sarvabad. Plagioclase (andesine-labradorite) and diopside, the main rock-forming minerals with minor augite, olivine and amphibole are the minerals of the host rocks. The chemical composition of the ilmenites showed that the average concentration of TiO2 increases from Kamyaran (43.19 wt.%) to Sarvabad (46.09 wt.%) and then to Marivan (47.42 wt.%). These minerals occur as interstitial fine to medium grains (up to 1.5 mm) and often in the amoeboid, anhedral and to a lesser extent as subhedral forms. Based on textural and mineral chemistry evidence, mineralization of titanium occurred as the result of magma oxidation. The oxidation of magma resulted in the formation of iron-titanium immiscible liquid droplets, following the plagioclase crystallization.
Keywords
Mineralization
Chromite
Ilmenite
Ophiolite
Geotectonic setting
Kurdistan

Subjects

Allahyari, K., Saccani, E., Rahimzadeh, B., and Zeda, O., 2014. Mineral chemistry and petrology of highly magnesian ultramafic cumulates from the Sarve-Abad (Sawlava) ophiolites (Kurdistan, NW Iran): New evidence for boninitic magmatism in intra-oceanic fore-arc setting in the Neo-Tethys between Arabia and Iran. Journal of Asian Earth Sciences 79: 312-328. https://doi.org/10.1016/j.jseaes.2013.10.005. 
Azizi, H., Lucci, F., Stern, R. J., Hasannejad, S., and Asahara, Y., 2018. The Late Jurassic Panjeh submarine volcano in the northern Sanandaj-Sirjan Zone, northwest Iran: Mantle plume or active margin?, Lithos, 308: 364-380.‏ https://doi.org/10.1016/j.lithos.2018.03.019 . 
Barnes, S. J., and Roeder, P. L., 2001. The range of spinel compositions in terrestrial mafic and ultramafic rocks. Journal of Petrology 42(12): 2279-2302. https://doi.org/10.1093/petrology/42.12.2279. 
Dick, H. J., and Bullen, T., 1984. Chromian spinel as a petrogenetic indicator in abyssal and alpine type peridotites and spatially associated lavas.Contributions to Mineralogy and Petrology 86(1): 54-76. https://link.springer.com/article/10.1007%2FBF00373711. 
Dilek, Y., and Furnes, H., 2014. Ophiolites and Their Origins. Elements 10(2): 93-100. https://doi.org/10.2113/gselements.10.2.93. 
Emami, M. H., Sadeghi, M. M., and Omrani, S. J., 1993.  Magmatic Map of Iran 1: 1,000,000: Geological Survey of Iran. internal report.‏ 
Farahat, E. S., 2008. Chrome-spinels in serpentinites and talc carbonates of the El Ideid-ElSodmein District, Central Eastern Desert, Egypt: Their metamorphism and petrogenetic implications. Geochemistry 68(2): 193-205. https://doi.org/10.1016/j.chemer.2006.01.003. 
Force, E. R., 1991. Geology of titanium-mineral deposits. Geological Society of America 259. DOI: https://doi.org/10.1130/SPE259.
Ismail, S. A., Mirza, T. M., and Carr, P. F., 2010. Platinum-group elements geochemistry in podiform chromitites and associated peridotites of the Mawat ophiolite, northeastern Iraq. Journal of Asian Earth Sciences 37(1): 31-41. https://doi.org/10.1016/j.jseaes.2009.07.005.
Johnson, C., 2012. Podiform chromitite at Voskhod, Kazakhstan. PhD thesis, University of Cardiff, Wales, UK. https://orca.cardiff.ac.uk/40714/. 
Kamenetsky, V. S., Crawford, A. J., and Meffre, S., 2001. Factors controlling chemistry of magmatic spinel: an empirical study of associated olivine, Cr-spinel and melt inclusions from primitive rocks. Journal of Petrology 42(4): 655-671. https://doi.org/10.1093/petrology/42.4.655. 
Leblanc, M., and Violette, J. F., 1983. Distribution of aluminum-rich and chromium-rich chromite pods in ophiolite peridotites. Economic Geology 78(2): 293-301. https://doi.org/10.2113/gsecongeo.78.2.293.
Mukherjee, R., Mondal, S. K., Frei, R., Rosing, M. T., Waight, T. E., Zhong, H., and Kumar, G. R., 2012. The 3.1 Ga Nuggihalli chromite deposits, Western Dharwar craton (India): geochemical and isotopic constraints on mantle sources, crustal evolution and implications for supercontinent formation and ore mineralization. Lithos, (155): 392-409. ‏https://doi.org/10.1016/j.lithos.2012.10.001. 
Nicolas, A., 1989. Structure of Ophiolites and Dynamics of Oceanic Lithosphere. Kluwer Academic Publishers, Dordrecht. https://doi.org/10.1007/978-94-009-2374-4. Publisher: Springer Dordrecht. eBook Packages: Springer Book Archive. 
Pearce, T. H., Russell, J. K., and Wolfson, I., 1987. Laser-interference and Nomarski interference imaging of zoning profiles in plagioclase phenocrysts from the May 18, 1980, eruption of Mount St. Helens, Washington. American Mineralogist 72(11-12): 1131-1143. 
Rajabzadeh, M. A., 1998. Minéralisation en chromite et éléments du groupe du platine dans les ophiolites d’Assemion et de Neyriz, ceinture du Zagros, Iran. PhD Thesis, Institut National Polytechnique de Lorraine, France. 
Rajabzadeh, M. A., and Moosavinasab, Z., 2012. Mineralogy and distribution of platinum-group minerals (PGM) and other solid inclusions in the Neyriz ophiolitic chromitites, Southern Iran. The Canadian Mineralogist 50(3): 643-665. Doi: 10.3749/canmin.50.3.000.
Rajish, K., Srivastava Chandra, R., and Shastry, A., 2004. High-Ti type N-MORB parentage of basaltsfrom the south Andaman ophiolite, India. Earth and Planetary Science Letters 113(4): 605-618. 
Shafaii Moghadam, H., Li, Q. L., Stern, R. J., Chiaradia, M., Karsli, O., and Rahimzadeh, B., 2020. The Paleogene ophiolite conundrum of the Iran–Iraq border region. Journal of the Geological Society 177(5): 955-964.‏ https://doi.org/10.1144/jgs2020-009. 
Shafaii Moghadam, H., Stern, R. J., and Chiaradia, M., 2013. Geochemistry and tectonic evolution of the Late Cretaceous Gogher-Bft ophiolite,central Iran. Lithos 168: 33-47. https://doi.org/10.1016/j.lithos.2013.01.013. 
Tian, L., Castillo, P. R., Hawkins, J. W., Hilton, D. R., Hanan, B. H., and Pietruszka, A. J., 2008. Major and trace element and Sr-Nd isotope signatures of lavas from the central Lau Basin: implications for the nature and influence of subduction components in the back- arc mantle. Volcanology and Geothermal Research 178(4): 657-670. https://doi.org/10.1016/j.jvolgeores.2008.06.039.
Uysal, I., Sadiklar, M. B., Tarkian, M., Karsli, O., and Aydin, F., 2005. Mineralogy and composition of the chromitites and their platinum-groupminerals from Ortaca (SW Turkey): evidence for ophiolitic genesis. Mineralogy and Petrology 83(3-4): 219-242. DOI:10.1007/s00710-004-0063-3.
Whitney, D. L., and Evans, B. W., 2010. Abbreviations for names of rock-forming minerals. American Mineralogist 95(1): 185-187. https://doi.org/10.2138/am.2010.3371.
Zhou, M. F., and Kerrich, R., 1992. Morphology and composition of chromite in komatiites from the Belingwe greenstone belt, Zimbabwe. The Canadian Mineralogist 30(2): 303-317.
Zhou, M. F., Robinson, P. T., Malpas, J., and Li, Z., 1996. Podiform chromitites in the Luobusa ophiolite (Southern Tibet): implications for melt-rock interaction and chromite segregation in the upper mantle. Journal of Petrology 37(1): 3-21. https://doi.org/10.1093/petrology/37.1.3.
Scientific Quarterly Journal of Geosciences
Volume 32, Issue 3 - Serial Number 125
Vol. 32,, Issue.3, Serial No. 125, Autumn 2022
Summer 2022
Pages 133-144