Document Type : Original Research Paper

Authors

1 Ph.D. Student, Department of Geology, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran

2 Professor, Department of Geology, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran

3 Associate Professor, Department of Geology, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran

Abstract

The Oshvad skarn type deposit was formed during the intrusion of a felsic mass into the Permian and Triassic carbonate rocks and ion exchange occurred between the intrusion mass and these units. In order to determine the properties of the mineralizing fluid in this skarn, several fluid inclusions in quartz and calcite minerals of the mineralization zone were analyzed. The results show that these minerals have two types of fluids inclusion. The first group includes L+V type, low to medium salinity, and with homogenization temperature of 194 to 480°C. The second group includes V+L type, low to moderate salinity, and homogenization temperature of 338 to 448°C. The origin of L+V type fluid inclusions are magmatic-meteoric and metamorphic type and V+L fluid inclusions are metamorphic type. Mixing and dilution of fluids occurred during the mixing of meteoric waters with magmatic-metamorphic fluids. These processes are the main factors of mineralization in this deposit. Fluid inclusions data show that fluid pressure has been 50 to 150 bars during the ore-forming minerals. Also, the fluid temperature has been between 200 to 360°C. The data suggest that the ore minerals have been formed in depth of 650 meters lower than the old water table.

Keywords

Main Subjects

References
Ahadnejad, V., Valizadeh, M. V., Deevsalar, R., and Rezaei-Kahkhaei, M., 2011- Age and geotectonic position of the Malayer granitoids: Implication for plutonism in the Sanandaj-Sirjan zone, W Iran. NeuesJahrbuchfürGeologie und Paläontologie, Abhandlungen, 261(1): 61–75. DOI: 10.1127/0077-7749/2011/0149.
Ahmad, S. N., and Rose, A. W., 1980- Fluid Inclusions in Porphyry and Skarn Ore at Santa Rita, New Mexico. Economic Geology,75: 229-250. https://doi.org/10.2113/gsecongeo.75.2.229.
Alavi, M., 1994- Tectonics of the Zagros orogenic belt of Iran: new data and interpretations. Tectonophysics, 229(3) :211-238. Doi: 10.1016/0040-1951(94)90030-2.
Barnes, H. L., 1997- Geochemistry of Hydrothermal Ore Deposits. John Wiley, New York.
Beane, R. E., 1983- The Magmatic–Meteoric Transition, Geothermal Resources Council, Special Report, 13: 245–253.
Drummond, S. E., and Ohmoto, H., 1985- Chemical evolution and mineral deposition in boiling hydrothermal systems. Economic Geology, 80: 126–147.
Duan, S., Zhang, Z., Jiang, Z., Zhao, J., Zhang, Y., Li, F., and Tian, J., 2014- Geology, geochemistry, and geochronology of the Dunde iron–zinc ore deposit in western Tianshan, China. Ore Geology Reviews, 57: 441-461. https://doi.org/10.1016/j.oregeorev.2013.08.019.
Goldstein, R. H., 2001- Fluid inclusions in sedimentary and diagenetic systems. Lithos, 55(1): 159–192. https://doi.org/10.1016/S0024-4937(00)00044-X.
Haas, J. L., 1971- The Effect of Salinity on the Maximum Thermal Gradient of a Hydrothermal System at Hydrostatic Pressure. Economic Geology, 66: 940-946. https://doi.org/10.2113/gsecongeo.66.6.940.
Hastie, A. R., Kerr, A. C., Pearce, J. A., and Mitchell, S., 2007- Classification of altered volcanic island arc rocks using immobile trace elements: development of the Th–Co discrimination diagram. Geology and geological evolution of Jamaica, 48(12): 2341-2357. DOI: 10.1093/petrology/egm062.
Kendy, G. C., 1950- Pneumatolysis and the liquid inclusion method of geologic thermometry. Economic Geology, 45: 533-547. https://doi.org/10.2113/gsecongeo.45.6.533.
Lingang, X., Jingwen, M., Fuquan, Y., Hennig, D., and Jianmin, Z., 2010- Geology, geochemistry and age constraints on the Mengku skarn iron deposit in Xinjiang Altai, NW China. Journal of Asian Earth Sciences, 39: 423-440. https://doi.org/10.1016/j.jseaes.2010.04.005.
Middlemost, E. A., 1994- Naming materials in the magma/igneous rock system. Earth-Science Reviews, 37(3-4): 215-224. https://doi.org/10.1016/0012-8252(94)90029-9.
Mohajjel, M., Fergusson, C. L., and Sahandi, M. R., 2003- Cretaceous–Tertiary convergence and continental collision, Sanandaj–Sirjan zone, western Iran. Journal of Asian Earth Sciences 21.4: 397-412. https://doi.org/10.1016/S1367-9120(02)00035-4
Nash, J. T., 1976- Fluid inclusion petrology-data from porphyry copper deposits and applications to exploration, US Geol. Surv. Prof. Paper 907 D 16 p.
Pearce, J. A., Harris, N, B., and Tindle, A. G., 1984- Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4): 956-983. https://doi.org/10.1093/petrology/25.4.956.
Potter, R. W., Clynne, M. A., and Brown, D. L., 1978- Freezing Point Depression of Aqueous Sodium Chloride Solution. Economic Geology, 73:  284-285. https://doi.org/10.2113/gsecongeo.73.2.284.
Roedder, E., 1984- Fluid inclusions, Reviews in Mineralogy, Mineralogical Society of America, Virginia, 12: 640p.
Shand, S. J., 1943- Eruptive rocks their genesis, composition, classification, and their relation to ore-deposits with a chapter on meteorite. John Wiley and Sons, New York.
Shepherd, T., Rankin, A. H., and Alderton, D. H. M., 1985- A Practical Guide to Fluid Inclusion Studies, Blackie, London 239p.
Tale fazel, E., Mehrabi, B., Khakzad, A. and Kianpour, R., 2011- Stages and Mineralization Conditions of Dardvey Iron Skarn Based on Mineralogy and Fluid Inclusion Evidences, Sangan Area (Khorasan Razavi). Scientific quarterly journal of geosciences, 82: 139-150. Doi: 10.22071/GSJ.2011.54450.
Van den Kerkhof, A. M., and Hein, U. F., 2001- Fluid inclusion petrography. Lithos, 55: 27-47. ‏https://doi.org/10.1016/S0024-4937(00)00037-2.
Viti, C., and Frezzotti, M. L., 2001- Transmission electron microscopy applied to fluid inclusion investigations. Lithos 55: 125-138. https://doi.org/10.1016/S0024-4937(00)00042-6.
Whitney, D. L., and Evans, B. W., 2010-Abbreviations for names of rock-forming minerals. Am Mineral, 95(1): 185-187. https://doi.org/10.2138/am.2010.3371.
Wilkinson, J. J., 2001- Fluid inclusions in hydrothermal ore deposits. Lithos, 55:  229- 272. https://doi.org/10.1016/S0024-4937(00)00047-5.
Zamanian, H., Sameti, M., Pazoki, A., Barani, N., and Ahmadnejad, F., 2017- Thermobarometry in the Sarvian Fe-skarn deposit (Central Iran) based on garnet–pyroxene chemistry and fluid inclusion studies. Arabian Journal of Geosciences, 10(3), p.54. Doi: 10.1007%2Fs12517-016-2785-z.
Zangeneh, M., Boumeri, M., and Biabangard, H., 2017- Investigation of skarn formation using petrographic, mineral chemistry and fluid inclusion data, south west of Khaf, (southeast of Razavi Khorasan Province). Iranian Journal of Crystallography and Mineralogy, 1: 35-48.
Zareie, R., Zamanian, H., Pazouki, A., Barani, N., and Zaal, F., 2016- Mineral chemistry and temperature condition investigations of the Sarvian Iron ore deposit (Markazi province, Delijan city). Iranian Journal of Crystallography and Mineralogy, 3: 435-448.
Zhang, Y. G., and Frantz, J. D., 1987- Determination of homogenization temperatures and densities of supercritical fluids in the system NaCl-KCl-CaCl2- H2O using synthetic fluid inclusions. Chemical Geology, 64: 335-350. https://doi.org/10.1016/0009-2541(87)90012-X.