0.707, N-MORB normalized patterns with enrichment in Low- and High Field Strength Elements (LFSE and HFSE) and depletion in P and Ti contents, chondrite-normalized patterns with flat heavy rare earth elements (HREE) patterns, magnetic susceptibility <10-5x100 (ilmenite series), no alteration, and no Sn, Cu, Pb, and Zn anomalies in whole rock composition of granitoids nor in the associated river sediments, absence of volcanic rocks, and occurrence of metamorphic rocks (slate and schist) during Cimmerian orogeny indicate the SaSZ granitoids are S-type granitoids formed in a continental collision zone. Discussion Geological, geophysical and geochemical characteristics of granitoids in Sanandaj-Sirjan Zone (such as the absence of volcanic arc and volcanic rocks, continental crust thickening (56-52 km) and the formation of large-scale (batholith) granitoids at depths >4 km, regional metamorphism at green schist facies (and amphibolite) following Cimmerian orogeny, low (Eu/Eu)N (reducing conditions), magnetic susceptibility <100x10-5 (ilmenite series), negative εNdi and (87Sr/86Sr)I >0.707) show that, unlike previous studies, these granitoids are S-type granitoids formed by melting the continental crust in a collisional zone. Therefore, tin mineralization might probably occurred in connection with them. However, there is ample evidence of the absence of tin mineralization by the magma that forms these S-type granitoids, that are including the lack of hydrothermal fluids and consequently mineralization potential (due to the absence of alteration minerals in ASTER satellite images), low content of tin, copper, lead and zinc elements in these granitoids Sanandaj-Sirjan Zone and associated river sediments, (Eu/Eu)N value > 0.2, Rb/Sr <3, low Y (10-75 ppm), Ba > 200 ppm, as well as the geological, geophysical and geochemical similarities to barren S-type (ilmenite series) granitoids in Lut block (in Najmabad, Sorkh kuh to Shah kuh areas) which have formed in a continental collision system during the Cimmerian orogeny. References Ahadnejad, V., Valizadeh, M., 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. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 261(1): 61–75. https://doi.org/10.1127/0077-7749/2011/0149 Bayati, M., Esmaeily, D., Maghdour-mashhour, R., Li, X. and Stern, R.J., 2017. Geochemistry and petrogenesis of Kolah-Ghazi granitoids of Iran: Insights into the Jurassic Sanandaj-Sirjan magmatic arc. Chemie der Erde- Geochemistry, 77(2): 281–302. https://doi.org/10.1016/j.chemer.2017.02.003 Esna-Ashari, A., Tiepolo, M., Valizadeh, M., Hassanzadeh, J. and Sepahi, A., 2012. Geochemistry and zircon U–Pb geochronology of Aligoodarz granitoid complex, Sanandaj-Sirjan Zone, Iran. Journal of Asian Earth Sciences, 43(1): 11–22. https://doi.org/10.1016/j.jseaes.2011.09.001 Ishihara, S., 1977. The Magnetite-series and Ilmenite-series Granitic Rocks. Mining Geology, 27(145): 293–305. https://doi.org/10.11456/shigenchishitsu1951.27.293 Khalaji, A.A., Esmaeily, D. and Valizadeh, M. V., 2007. Petrology and geochemistry of the granitoid complex of Boroujerd, Sanandaj-Sirjan Zone, Western Iran. Journal of Asian Earth Sciences, 29(5-6): 859–877. https://doi.org/10.1016/j.jseaes.2006.06.005 Neiva, A.M.R., 2002. Portuguese granites associated with Sn-W and Au mineralizations. Bulletin of the Geological Society of Finland, 74: 79–101. https://doi.org/10.17741/bgsf/74.1-2.003 Shahbazi, H., Siebel, W., Pourmoafee, M., Ghorbani, M., Sepahi, A.A., Shang, C.K. and Abedini, M.V., 2010. Geochemistry and U – Pb zircon geochronology of the Alvand plutonic complex in Sanandaj – Sirjan Zone (Iran): New evidence for Jurassic magmatism. Journal of Asian Earth Sciences, 39(6): 668–683. https://doi.org/10.1016/j.jseaes.2010.04.014 Takahashi, M., Aramaki, S. and Ishihara, S., 1980. Magnetite-Series/Ilmenite Series vs. I-type/S-type granitoids, Granitic Magmatism and related mineralization. Mining Geology, Special Issue, 8: 13–28. Tahmasbi, Z., Castro, A., Khalili, M., Khalaji, A.A. and De, J., 2010. Petrologic and geochemical constraints on the origin of Astaneh pluton, Zagros. Journal of Asian Earth Sciences, 39(3): 81–96. https://doi.org/10.1016/j.jseaes.2010.03.001 Zheng, W., Mao, J., Zhao, C., Zhang, Z., Xiao, W., Ji, W., Majidifard, M.R., Rezaeian, M., Talebian, M., Xiang, D., Chen, L., Wan, B., Ao, S. and Esmaeili, R., 2018. Geochemistry, zircon U-Pb and Hf isotope for granitoids, NW Sanandaj-Sirjan zone, Iran: Implications for Mesozoic-Cenozoic episodic magmatism during Neo-Tethyan lithospheric subduction. Gondwana Research, 62: 227–245. https://doi.org/10.1016/j.gr.2018.04.002]]>
p. 1−28
2423-5865
Vol.13/No.1
p. 29−55
2423-5865
Vol.13/No.1
1) in all of the samples. Moreover, a strong negative correlation was observed between Sr and Y in the studied apatite and monazites. Fluid inclusions within the apatites were classified into eight groups: a) one-phase gaseous inclusions, b) one-phase liquid inclusions, c) two-phase liquid rich inclusions (L+V), d) two-phase gas-rich inclusions (V+L), e) two-phase liquid- solid inclusions (L+V), f) three-phase inclusions (V-L-S), g) three-phase CO2 bearing inclusions associated with formation of clathrate, and h) melt inclusions. The composition of the fluid inclusions is plotted in magmatic and hydrothermal fields. The salinity of most of the inclusions is low to medium (5-21 wt.% NaCl) and homogenization temperature ranges from 250 to 350˚C. Also, a limited number of fluid inclusions were homogenized in the range of 378-486 ˚C, indicating high salinity (43 to 54 wt.% NaCl). The fluid trapping depths were measured to be in the range 100-1700 m. Discussion The Esfordi iron-apatite deposit is located NE of Bafq, Yazd province and it hosts three types of apatite mineralization in massive, vein, and disseminated forms, as well as REE-bearing minerals. Periodic variations in mineralizing fluid is evidenced by changes in REE content of the studied minerals. The presence of monazite in dark phases of the host apatite mineral indicates leaching of REE from the host apatite and redeposition during the nucleation of monazite grains (Heidarian et al., 2017). Mineralogical data indicated that the apatites are of the fluorapatite type with minor contents of chloride (Rajabzadeh et al., 2013). The quantities of Sr and Y in the studied minerals indicate a strong negative correlation, consistent with magmatic differentiation. In addition, the concentrations of Mn, Sr, and Y support the granitoid origin of the Esfordi deposit (Belousova et al., 2002). Microthermometric data plotted on magmatic and hydrothermal fields indicated that mixing fluids and boiling are the important factors in mineralization. Upon the obtained data of the present study, main parts of the Esfordi iron phosphate deposit have been formed at temperatures ranging from 146 to 486˚C and depths of 100 to 1700 m. Acknowledgements The authors appreciate Shiraz University Research Council for their support of this work. The Director General and personnel of the Esfordi Mine Company are acknowledged for their assistance in the field works. References Belousova, E.A., Griffin, W.L., O’Reilly, S.Y. and Fisher, N.I., 2002. Apatites as indicator mineral for mineral exploration: trace-element compositions and their relationship to host rock type. Journal of Geochemical Exploration, 76(1): 45–69. https://doi.org/10.1016/S0375-6742(02)00204-2 Heidarian, H., Alirezaei, S. and Lentz, D., 2017. Chadormalu Kiruna-type magnetite–apatite deposite, Bafq district, Iran: Insights in to hydrothermal alteration and petrogenesis from geochemical, fluid inclusion and sulfur isotope data. Ore Geology Reviews, 83(7): 43–62. https://doi.org/10.1016/j.oregeorev.2016.11.031 Rajabzadeh, M.A., Hoseini. K. and Moosavinasab. Z., 2013. Mineralogical and geochemical studies on apatites and phosphate host rocks of Esfordi deposit, Yazd province, to determine the origin and geological setting of the apatite. Journal of Economic Geology, 6(2): 331–353. (in Persian with English abstract) https://dx.doi.org/10.22067/ECONG.V6I2.20956 ]]>
p. 57−84
2423-5865
Vol.13/No.1
98%. Each sample was reacted with Cu2O powder to produce SO2. The SO2 gas was collected and purified, and followed by S isotopic analysis using a MAT252 mass spectrometer at stable isotope laboratory of the University of Arizona. The δ34S values were reported relative to Vienna Cañon Diablo Troilite (VCDT), and analytical precision is ±0.2‰. Results and discussion Based on field and petrographic observations, three mineralization stages including diagenetic, hydrothermal (early-ore, main-ore and late-ore substages), and supergene stages were identified at the Chaldaq deposit. At least six types of pyrite and arsenian pyrite were recognized at the Chaldaq deposit. On the basis of EPMA results, gold with 10 to 80 ppm Au content occurs as solid solution (Au+)in arsenian pyrite [(Fe2+As3+)S2Au2.S0]. Various studies have documented that gold in the primary ores of sediment-hosted gold deposits is largely hosted by arsenian pyrite, and that gold in occurs as a substituting cation in the form of solid solution (Au+) and/or as nanoparticles of native gold (Au0) (Cook and Chryssoulis, 1990; Fleet and Mumin, 1997; Reich et al., 2005). Au– and Au3+ have also been suggested to occur as solid solution in pyrite (Arehart et al., 1993; Li et al., 2003). The understanding of the chemical state of gold in iron sulfides is important for deep understanding of gold depositional mechanism in sediment-hosted gold deposits. Main-ore substage sulfide minerals has δ34S values ranging from 3.5 to 6.5 ‰ (avg. 5‰, n=6). The Fe content of sphalerites from the main-ore indicates that sphalerite precipitated from relatively low fS2 fluid. Based on all evidence, it can be said that sulfur mineralization of the Chaldaq prospect has been formed by the performance of oxidized hydrothermal fluid on organic-bearing carbonaceous host rocks (at the Chaldaq unit) and the systematic subtraction of H2S reductive species from that environment. Considering the low temperature (fS2 between -14 to -16) and the acidic to neutral pH (presence of kaolinite and illite) for the main-ore stage of hydrothermal mineralization in the Chaldaq prospect, probably the major contribution of sulfur is in the form of H2S. References Arehart, G.B., Chryssoulis S.L. and Kesler, S.E., 1993. Gold and arsenic in iron sulfides from sediment-hosted disseminated gold deposits: implications for depositional processes. Economic Geology, 88(3): 171–185. https://doi.org/10.2113/gsecongeo.88.1.171 Cook, N.J. and Chryssoulis S.L., 1990. Concentrations of invisible gold in the common sulfides. Canadian Mineralogist, 28(3): 1–16. https://doi.org/10.1007/s00126-0140562-z Fleet, M.E. and Mumin, A.H., 1997. Gold-bearing arsenian pyrite and marcasite and arsenopyrite from Carlin trend gold deposits to laboratory synthesis. American Mineralogist, 82(3): 182–193. https://doi.org/10.2138/am-1997-1-220 Li, J.L., Qi, F. and Xu, Q.S., 2003. A negatively charged species of gold in minerals–further study of chemically bound gold in arsenopyrite and arsenian pyrite. Neues Jahrbuch für Mineralogie-Abhandlungen, 5(2): 193–214. https://doi.org/10.1127/0028-3649/2003/2003-0193 Mehrabi, B., Yardley, B.W.D. and Cann, J.R., 1999. Sediment-hosted, disseminated gold mineralisation at Zarshuran, NW Iran. Mineralium Deposita, 34(3): 656–671. https://doi.org/10.1007/s001260050227 Reich, M., Kesler, S.E., Utsunomiya, S., Palenik, C.S., Chryssoulis, S.L. and Ewing, R.C., 2005. Solubility of gold in arsenian pyrite. Geochimica and Cosmochimica Acta, 69(6): 2781–2796. https://doi.org/10.1016/j.gca.2005.01.011]]>
p. 85−111
2423-5865
Vol.13/No.1
p. 113−144
2423-5865
Vol.13/No.1
1000 ℃ in mantle or subduction zones of continental margins, and (2) S-type (low-temperature or Caledonian granitoids with inherited zircons) granites formed by partial melting of felsic crust at ~700-800 ℃. Northeast of Iran is a key location for studying the Cimmerian Orogeny, which is related to the Late Triassic collision between it and Eurasia, and the closure of the Paleo-Tethys (Samadi et al., 2014). Mesozoic Mashhad granitoids have cropped out along with the Paleo-Tethys suture zone. Distinct granitoid suites, i.e., monzogranite, granodiorite, tonalite, and diorite occur in Mount Khalaj located in the south of Mashhad. It comprises of monzogranite and granodiorite. However, monzogranite is the most abundant. To study the plutonic events during the Turan and Central Iran collision, the origin and tectonic setting of monzogranite of Mount Khalaj are investigated in this study based on whole rock geochemical data.
Materials and methods
This research study is based on field studies and petrography. Fresh thin sections samples were selected for geochemical analysis. Whole rock composition was measured on pressed powder tablets by X-ray fluorescence (XRF) using a Philips PW 1480 wavelength dispersive spectrometer with a Rh-anode X-ray tube and a 3 MeV electron beam Van de Graaff Accelerator, at the center for Geological Survey of Iran. The trace element data of a sample was measured at the Activation Laboratories, Ontario, Canada (ActLabs). Samples were digested by lithium metaborate/tetraborate fusion and analyzed with a Perkin Elmer Sciex ELAN 6000, 6100 or 9000 ICP/MS. GCDkit 4.1 and CorelDraw software packages were used for plotting diagrams and calculation of saturation temperatures.
Results
The Khalaj granitoid is mineralogically composed of quartz, potassic feldspar, plagioclase, mica, and accessory minerals of zircon and apatite. Geochemically, it is an unaltered acidic intrusion with ~72-73 wt.% SiO2. It is a granitoid (monzogranite) based on various classification diagrams (e.g., Cox et al., 1979; etc.). It shows the peraluminous nature (A/CNK~ 1.08-1.24) with negative Eu anomaly of ~0.62-0.73 (Eu/Eu*<1), low HREE and high LREE and LILE contents.
Discussion
Geochemically, the low HREE and high LREE and LILE content in the Mount Khalaj monzogranite indicate a more differentiated melt for it. Monzogranite samples from the Khalaj-Khajeh Morad regions are similar to ferroan alkali-calcic, felsic peraluminous S-type granitoids based on discrimination diagrams by various researchers (e.g., Chappell and White, 2001; Villaseca et al., 1998). In fact, the Mount Khalaj monzogranite is a collisional granite (based on diagrams by: Batchelor and Bowden, 1985; Sahin et al., 2004), produced by anatexis and partial melting of felsic upper crust pelitic sediments (based on diagrams by: Almeida et al., 2007; Patiño Douce, 1999). It is classified as a low-temperature S-type granite formed at 730-800 ℃ (based on the diagram of Rapp and Watson, 1995), with TZr of ~732-745 ℃ (by using GCDKit software). Therefore, S-type syn- to post-collisional Mount Khalaj monzogranite is a consequence of partial melting (anatexis) of hydrous sedimentary rocks of upper crust after Paleo-Tethys subduction under Turan plate and continental collision and compressional tectonism.
References
Almeida, M.E., Macambira, M.J.B. and Oliveira, E.C., 2007. Geochemistry and zircon geochronology of the I-type high-K calc-alkaline and S-type granitoid rocks from southeastern Roraima, Brazil: Orosirian collisional magmatism evidence (1.97-1.96 Ga) in central portion of Guyana Shield. Precambrian Research, 155(1–2): 69–97. https://doi.org/10.1016/j.precamres.2007.01.004
Barbarin, B., 1999. A review of the relationships between granitoid types, their origin and their geodynamic environments. Lithos, 46(3): 605–626. https://doi.org/10.1016/S0024-4937(98)00085-1
Batchelor, R.A. and Bowden, P., 1985. Petrogenetic interpretation of granitoid rocks series using multicationic parameters. Chemical Geology, 48(1–4): 43–55. https://doi.org/10.1016/0009-2541(85)90034-8
Chappell, B.W. and White, A.J.R. 2001. Two contrasting granite types: 25 years later. Australian Journal of Earth Sciences, 48: 489–499. https://doi.org/10.1046/j.1440-0952.2001.00882.x
Chappell, B.W. and White, A.J.R., 1992. I- and S-type granites in the Lachlan fold belt. Earth and Envioronmental Sciennce Transactions of The Royal Society Edinburgh, 83(1–2): 1–26. https://doi.org/10.1017/S0263593300007720
Chappell, B.W., Bryant, C.J., Wyborn, D., White, A.J.R. and Williams, I.S., 1998. High- and low-temperature I-type granites. Resource Geology, 48(4): 225–236. https://doi.org/10.1111/j.1751-3928.1998.tb00020.x
Cox, K.G., Bell, J.S. and Pankhurst, R.J., 1979. The interpretation of igneous rocks. Allen and Unwin, London, 450 pp. https://doi.org/10.1007/978-94-017-3373-1
Frost, B.R., Barnes, C.G., Collins, W.J., Arculus, S.R.J., Ellis, D.J. and Frost, C.D., 2001. A geochemical classification for granitic rocks. Journal of Petrology, 42(11): 2033–2048. https://doi.org/10.1093/petrology/42.11.2033
Patiño Douce, A.E., 1999. What do experiments tell us about the relative contributions of crust and mantle to the origins of granitic magmas? Geological Society, London, Special Publication, 168: 55–75. https://doi.org/10.1144/GSL.SP.1999.168.01.05
Pitcher, W.A.S., 1993. The nature and origin of granite. Chapman and Hall, London, 321 pp. https://doi.org/10.1007/978-94-011-5832-9
Rapp, R.P. and Watson, E.B., 1995. Dehydration melting of metabasalt at 8–32 kbar: Implications for continental growth and crust-mantle recycling. Journal of Petrology, 36(4): 891–931. https://doi.org/10.1093/petrology/36.4.891
Sahin, S.Y., Güngör, Y. and Boztuğ, D., 2004. Comparative petrogenetic investigation of Composite Kaçkar Batholith granitoids in Eastern Pontide magmatic arc-Northern Turkey. Earth, Planet and Space, 56(4): 429–446. https://doi.org/10.1186/BF03352496
Samadi, R., Mirnejad, H., Kawabata, H., Valizadeh, M.V., Harris, C. and Gazel, E., 2014. Magmatic garnet in the Triassic (215 Ma) Dehnow pluton of NE Iran and its petrogenetic significance. International Geology Review, 56(5): 596–621. https://doi.org/10.1080/00206814.2014.880659
Villaseca, C., Barbero, L. and Herreros, V., 1998. A re-examination of the typology of peraluminous granite types in intracontinental orogenic belts. Earth and Envioronmental Sciennce Transactions of The Royal Society Edinburgh, 89(2): 113–119. https://doi.org/10.1017/S0263593300007045]]>
p. 145−164
2423-5865
Vol.13/No.1
p. 165−192
2423-5865
Vol.13/No.1
p. 193−213
2423-5865
Vol.13/No.1
p. 215−242
2423-5865
Vol.13/No.1