100°C), with a reproducibility of ±1°C. However, it was reduced to 0.1–0.5°C/min near phase transformation, with a reproducibility of ±0.1°C.
Results
Mineralization that occurs in the area is mainly related to the Sheiviar Dagh intrusive rocks and it includes a variety of types of skarn, porphyry- and vein-type, epithermal and intrusion related deposits. Agh Daragh mineralization occurs at least in three states including: 1) stockwork-disseminated, 2) vein-type and 3) replacement (skarn). In order to determine the nature and characteristics of granodiorites hosted Ayran Goli mineralization, the biotites points were analyzed. The Ayran Goli granodiorite with calc-alkaline nature is related to orogenic zones that is associated with subduction zones. To determine the chemical properties of the minerals in Gowdal skarn mineralization, garnet and chlorite have been used for analysis which are often located at repidolite and picnochlorite positions. Electron micro probe analysis (EMPA) of magnetite from the Chupanlar area showed that it belongs to porphyry and Kiruna type deposits. Based on the observations made, three types of aqueous fluid inclusions were distinguished in the quartz-sulfide veins, including halite-saturated aqueous (H2O–NaCl±KCl), aqueous two-phase (H2O–NaCl±CaCl2), and monophase liquid and vapor fluid inclusions.
Discussion
Because of the lack of CO2-bearing fluid inclusions phase in the samples, we used a temperature-pressure relationship intersection in order to obtain the depth of mineralization. However, but at this study salt-rich inclusions (type 1) the dissolution of halite homogeneous solid phase (Bodnar, 1994) were used in order to estimate the standing deposit. Considering the temperature of the liquid-vapor homogenization (Thl-v), temperatures between 201 to 474°C, homogenization halite (TmNaCl) between 196 to 434°C (48 wt% NaCl eq.) in the solid phase inclusions with halite, minimum and the maximum pressure between 4.0 and 7.2, respectively that occur at 0.4 to 2.7 kb (average of 5.1 kb and 4 km depth) under lithostatic pressure. These conditions are consistent with the occurrence of gold porphyry copper deposits introduced by Hedenquist et al., (1998). The presence of gas-phase inclusions (type 3), gas-rich (type 2) and a solid-bearing phase, halite (type 1) in a mixture of fluid inclusions indicates the occurrence of fluid immiscibility (Bodnar, 1995; Fournier, 1999). In such circumstances, homogenization temperature inclusions are trapped as their temperature is taken. Petrographic evidence on the simultaneous presence of these two categories is stored as the initial fluid temperature up 400 to 500°C with boiling and fluid immiscibility.
References
Aghazadeh, M., 2009. Petrology and geochemistry of the Anzan-Khan Kandi and Sheivier Dagh granitoids (north and east of Ahar, East of Azerbijan). PhD thesis, Tarbiat Modares University, Tehran, Iran, 493 pp. (in Persian with English abstract)
Bodnar, R.J., 1994. Synthetic fluid inclusions: XII: the system H2O–NaCl. Experimental determination of the halite liquidus and isochores for a 40 wt.% NaCl solution. Geochimica et Cosmochimica Acta, 58(3): 1053–1063.
Bodnar, R.J., 1995. Revised equation and table for determining the freezing point depression of H2O-NaCl solutions. Geochimical et Cosmochimica Acta, 57(3): 683-684.
Fournier, R.O., 1999. Hydrothermal processes related to movement of fluid from plastic to brittle rock in the magmatic-epithermal environment. Economic Geology, 94(8): 1193-1212.
Hedenquist, J.W., Arribas, A. and Reynolds, T.J., 1998. Evolution of an intrusion-centered hydrothermal system: Far Southeast Lepanto porphyry and epithermal Cu-Au deposits, Philippines. Economic Geology, 93(4): 374-404.
Nabavi, M.H., 1976. An introduction to the Iranian geology. Geological Survey of Iran, Tehran, 110 pp.]]>
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52.99 wt.% NaCl equiv., which are most similar to the results of the other Iranian porphyry copper deposits. Being located in the quartz-sericite-pyrite alteration zone, the results of thermometry indicates that ore deposition in the Iju deposit has occurred via mixing of magmatic and surface fluids. Variations in salinity and paragenesis of the saline multiphase fluid inclusions and two-phase gas-rich fluid inclusions indicate the occurrence of boiling phenomenon in some samples of the Iju deposit. The amount of δ34S for pyrite has a limited range close to zero (average, 0.229‰) that shows a magmatic origin for sulfur. Considering the presence of subvolcanic rocks, the type and extension of alteration zones, the structure and texture of ore bodies, thermometry results of fluid inclusions and sulfur isotope values, the Iju deposit is similar to porphyry copper deposits.
Discussion
In the quartz-sericite-pyrite zone, three main groups of veinlets have been identified. The quartz+pyrite veinlets are more abundant than the other types and they were selected for fluid inclusions and stable isotope studies. Petrographic studies of fluid inclusions identifies two groups of fluids including: 1- fluid inclusions without the halite phase, including the types L+V, L+V+S1 and (L+V+S1+S2, that is secondary), 2- fluid inclusions with halite phase, including the types L+V+H, L+V+H+S1, L+V+H+S1+S2 and L+V+H+S1+An. Homogenization temperature and salinity for the fluid inclusions without halite phase are as follows: 140 to 380°C and 0.18 to 24 wt.% NaCl (Fig. 8A and C) and for the fluid inclusions with halite phase they range from 230 to 480°C and 30 to 52 wt.% NaCl (Fig. 9A, B and D), In addition, the pressure and depth for the fluid inclusions containing halite phase are 750 bar and 3500 m on the average. Fluid inclusions available at the quartz veinlets of porphyry copper deposits can be formed in a wide range of chemical composition and under different temperature and pressure conditions (Rusk and Reed, 2008). The wide range in fluid inclusions data of the Iju deposit can be justified by physicochemical changes in the fluid as it is boiling and mixing with the surface fluids. Cooling, fluids mixing, boiling and fluid-rock reaction play important roles in the settling of chalcopyrite from the hydrothermal fluid and the dilution of saline ore-bearing fluids can cause the formation of copper ores from the ore-bearing fluid (Ulrich et al., 2002). Pyrite δ34S value ranges from -0.86 to +1.27‰ (average, +0.22‰) and the δ34SH2S value of the syngenetic fluid with pyrite ranges from -0.23 to -2.36‰ (average, -1.17‰). The limited and near zero range that is observed about δ34S value of the sulfur minerals indicates the controlling role of magmatic processes in the mineralization events (Chen et al., 2009).
Acknowledgments
This article is related to Project No. 27124.3 dated 2015, 2, 7 at the Ferdowsi University of Mashhad. We are thankful to and appreciate the Research and Development center of National Iranian Cu Industries (Shahr-e-Babak, Meiduk), especially S.M. Mousavi, for the financial support of this project and the necessary proceedings.
References
Chen, Y.J., Piranjno, F., Li, N., Guo, D.Sh. and Lai, Y., 2009. Isotope systematica and fluid inclusion studies of the Qiyugou breccia pipe- hosted gold deposit, Qinling Orogen, Henan province, China: Implication for ore genesis. Ore Geology Reviews, 35(2): 245-261.
Dimitrijevic, M.D., 1973. Geology of Kerman region. Geological Survey of Iran, Tehran, Report No. Yu/52, 334 pp.
Hassanzadeh, J., 1993. Metallogenic and tectonomagmatic events in the SE sector of the Cenozoic active continental margin of central Iran (Shahr e Babak area, Keman Province). Ph.D. thesis, University of California, Los Angeles, America, 204 pp.
Rusk, B.G. and Reed, M.H., 2008. Fluid inclusion evidence for magmatic-hydrothermal fluid evolution in the porphyry copper- molybdenum deposit at Butte, Montana. Economic Geology, 103(2): 307-334.
Ulrich, T., Gunther, D. and Heinrich, C.A., 2002. The evolution of a porphyry Cu-Au deposit, based on LA-ICP-MS analysis of fluid inclusions: Bajo de la Alumbrera, Argentina. Economic Geology, 97(8): 1889-1920.]]>
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0.3 and AlIV > 0.7 which reveal the presence of primary oxidative magma in the Dalli porphyry Cu-Au deposit. Oxidative conditions seem to have prevailed during the onset of the hydrothermal stage of the Dalli porphyry deposit. This is because it has been confirmed by laser Raman spectroscopy analyses that the most primitive quartz veins in the potassic alteration of the Dalli deposit are characterized by the presence of anhydrite and hematite minerals (see Zarasvandi et al., 2015b). Also, microthermometry results on the most primitive barren quartz veins in potassic alteration represent temperatures as high as 620oC which indicate the beginning temperature of hydrothermal conditions.
Acknowledgements
Many thanks are due to the office of vice-chancellor of the Shahid Chamran University of Ahvaz for valuable information concerning the field work and sampling.
References
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Titley, S.R. and Beane, R.E., 1981. Porphyry copper deposits. Part 1. Geologic Setting, Petrology, and Tectogenesis. In: J.W. Hedenquist, J.F.H. Thompson, R.J. Goldfarb and J.P. Richards (Editors), Economic Geologists, 75th Anniversary Volume. Society of Economic Geologists, U.S.A, pp. 214-234.
Wang, R., Richards, J.P., Hou, Z.Q., Yang, Z.M., Gou, Z.B. and DuFrane, A., 2014. Increasing Magmatic Oxidation State from Paleocene to Miocene in the Eastern Gangdese Belt, Tibet: Implication for Collision-Related Porphyry Cu-Mo ±Au Mineralization. Economic Geology, 109(7): 1943–1965.
Zarasvandi, A., Rezaei, M., Sadeghi, M., Lentz, D., Adelpour, M. and Pourkaseb, H., 2015a. Rare earth element signatures of economic and sub-economic porphyry copper systems in Urumieh–Dokhtar Magmatic Arc (UDMA), Iran. Ore Geology Reviews, 70: 407-423.
Zarasvandi, A., Rezaei, M., Raith, J., Lentz, D., Azimzadeh, A.M. and Pourkaseb, H., 2015b. Geochemistry and fluid characteristics of the Dalli porphyry Cu–Au deposit, Central Iran. Journal of Asian Earth Sciences, 111: 175-191.]]>
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Ca, with Ca/K ratios between 0.01 to 1, whereas non magmatic fluids are often richer in Ca with Ca/K between 1 to 100 (Yardley, 2005). The amounts of Fe and Cu in magmatic fluids are commonly above 10000 and 1000 ppm, respectively. However, it depends on chlorinity (Fisher and Kendrick, 2008; Gillen, 2010; Appold and Wenz, 2011). Mn concentrations are 424 to 3645 ppm, with an average concentration of 7581 ppm. Mn/Fe ratio is varied from 0.21 to 1.87 with an average of 0.60.The wide range of homogenization temperature (170 -450 °C) and salinity (31- 52 wt % NaCl equiv) of the fluid inclusions and ratios of K/Ca in fluid inclusions indicate different fluid sources with magmatic and basinal type fluids (Yardley, 2005). Mn/Fe ratios in fluid inclusions are in wide ranges (0.21 -1.87) which indicate the presence of both reduced type and oxidized type fluids (Fisher and Kendrick, 2008).
Results
In addition to iron oxide, economical Cu mineralization occurs in the Jalal Abad deposit with Au, Bi and As mineralzation with insignificant apatite. The K, Fe, Ca, Na and Cu concentrations in fluid inclusions are most probably related to the mixing of magmatic and basinal fluids. The mineralogical, microthermometry and chemistry of fluid inclusions data show that magmatic-hydrothermal metal bearing fluids, nonmagmatic hydrothermal fluids and mixing of them are responsible for iron-Cu-Au mineralization (IOCG) in the Jalal- Abad deposit.
References
Appold, M.S. and Wenz, Z.J., 2011. Composition of Ore Fluid Inclusions from the Viburnum Trend, Southeast Missouri District, United States: Implications for Transport and Precipitation Mechanisms. Economic Geology, 106(1): 55-78.
Fisher, L.A. and Kendrick, M.A., 2008. Metamorphic fluid origins in the Osborne Fe oxide–Cu–Au deposit, Australia: Evidence from noble gases and halogens. Mineralium Deposita, 43(5): 483–497.
Gillen, D., 2010. A study of IOCG-related hydrothermal fluid in the Wernecke Mountains, Yukon Territory, Canada. Ph.D. thesis, James Cook University, Queensland, Australia, 562 pp.
S Stosch, H.G., Romer, R.L. and Daliran, F., 2011. Uranium–lead ages of apatite from iron oxide ores of the Bafq District, East-Central Iran. Mineralium Deposita, 46(1): 9–21.
Yardley, B.W.D., 2005. 100th Anniversary Special Paper: metal concentrations in crustal fluids and their relationship to ore formation. Economic Geology, 100(4): 613–632.]]>
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