Shadan deposit (Lut block): the first gold-rich porphyry deposit in Iran

Authors

1 School of Geology- Faculty of Science- University of Tehran

2 faculty of science- school of geology- university of Tehran

3 School of Geology, Faculty of Science. University of Tehran

Abstract

Shadan gold deposit is located 60 km southwest of Birjand and north of Lut block. the Eocene post-collision magmatism resulting from the subduction of the Sistan Ocean has played a role in the formation of the Shadan gold deposit. Gold mineralization in Shadan deposit is directly related to the emplacement of plutonic and sub volcanic plutons with a composition diorite to monzodiorite that intruded into andesite-pyroclastic units. The main alterations in the area are primary potassic and propylitic alterations, the first of which is located in the center of the hydrothermal-magmatic system and the second of which surrounds the potassic alteration. These two alterations are overprinted by the late Phyllic and Argillic alterations. Mineralization in Shadan deposit occurred in the form of stockwork, vein-veinlets, disseminated and hydrothermal breccias and the most important trigger of gold mineralization in this deposit was Shadan pluton. According to SEM studies, the most important host of gold in the hypogene part is pyrite and gold occurs as native, electrum and calavarite. The most characteristic veins of Shadan gold deposit are M and A type and banded veins. Shadan pluton contains abundant hornblende phenocrysts and biotite as well as high amounts of magnetite in various alterations which can indicate the presence of a highly oxidized magma with high amounts of water. Based on all the mentioned evidences as well as the Cu / Au ratio (3000), Shadan deposit can be introduced as the first gold-rich porphyry deposit in Iran.

Keywords


Aghazadeh, M., Hou, Z., Badrzadeh, Z. Zhou, L., 2015. Temporal–spatial distribution and tectonic setting of porphyry copper deposits in Iran: constraints from zircon U–Pb and molybdenite Re–Os geochronology. Ore geology reviews 70, 385-406. https://doi.org/10.1016/j.oregeorev.2015.03.003.
Arjmandzadeh, R., Alirezaei, S. Almasi, A., 2022. Tectonomagmatic reconstruction of the Upper Mesozoic-Cenozoic Neotethyan arcs in the Lut block, East Iran: a review and synthesis. Turkish Journal of Earth Sciences 31(6), 20-54. https://doi:10.55730/1300-0985.1818.
Asadi, H.H., Voncken, J.H.L., Kühnel, R.A. Hale, M., 2000. Petrography, mineralogy and geochemistry of the Zarshuran Carlin-like gold deposit, northwest Iran. Mineralium Deposita 35, 656-671.   https://doi.org/10.1007/s001260050269.
 Amraei, S. Niroomand, S., 2016. Mineralogy, Alterations, Lithogeochemical Investigations and Fluid Inclusions Studies in Kudkan Cu-Au Mineralization Area, Southern Khorasan, Iran. Advanced Applied Geology 6(1), 34-47. https://doi.org/10.1007/s001260050269.
Bodnar, R.J., Lecumberri-Sanchez, P., Moncada, D. Steele-MacInnis, M., 2014. Fluid inclusions in hydrothermal ore deposits. Treatise On Geochemistry 13, 119-142. https://doi.org/10.1016/B978-0-08-095975-7.01105-0.
Camp, V.E. Griffis, R.J., 1982. Character, genesis and tectonic setting of igneous rocks in the Sistan suture zone, eastern Iran. Lithos 15(3), 221-239. https://doi.org/10.1016/0024-4937(82)90014-7.
Eshraghi, H., Rastad, E. Motevali, K., 2010. Auriferous sulfides from Hired gold mineralization, south Birjand, Lut block, Iran. Journal of Mineralogical and Petrological Sciences 105(4), 167-174. https://doi.org/10.2465/jmps.070414b.
Golonka, J., 2004. Plate tectonic evolution of the southern margin of Eurasia in the Mesozoic and Cenozoic. Tectonophysics 381(1-4), 235-273. https://doi.org/10.1016/j.tecto.2002.06.004.
Gustafson, L.B. Hunt, J.P., 1975. The porphyry copper deposit at El Salvador, Chile. Economic Geology 70(5), 857-912. https://doi.org/10.2113/gsecongeo.70.5.857.
Hedenquist, J.W., Arribas, A. 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), 373-404. https://doi.org/10.2113/gsecongeo.93.4.373.
Hezarkhani, A., Williams-Jones, A.E. Gammons, C.H., 1999. Factors controlling copper solubility and chalcopyrite deposition in the Sungun porphyry copper deposit, Iran. Mineralium Deposita 34, 770-78. https://doi.org/10.1007/s001260050237.
Heidari, S.M., Daliran, F., Paquette, J.L. and Gasquet, D., 2015. Geology, timing, and genesis of the high sulfidation Au (–Cu) deposit of Touzlar, NW Iran. Ore Geology Reviews 65, 460-486. https://doi.org/10.1016/j.oregeorev.2014.05.013.
Jones, B.K., 1992. Application of metal zoning to gold exploration in porphyry copper systems. Journal of Geochemical Exploration 43(2), 127-155. https://doi.org/10.1016/0375-6742(92)90003-Q.
Karimpour, M.H., Stern, C., Farmer, L.  Saadat, S., 2011. Review of age, Rb-Sr geochemistry and petrogenesis of Jurassic to Quaternary igneous rocks in Lut Block, Eastern Iran. Geopersia 1(1), 19-54.. https://dx.doi.org/10.22059/jgeope.2011.22162.
Karimpour, M.H., Malekzadeh Shafaroudi, A., Farmer, G.L.  Stern, C.R., 2012. Petrogenesis of Granitoids, U-Pb zircon geochronology, Sr-Nd Petrogenesis of granitoids, U-Pb zircon geochronology, Sr-Nd isotopic characteristics, and important occurrence of Tertiary mineralization within the Lut block, eastern Iran. Journal of Economic Geology 4(1), 1-27. https://dx.doi.org/10.22067/econg.v4i1.13391.
Kesler, S.E., 1973. Copper, molybdenum and gold abundances in porphyry copper deposits. Economic Geology 68(1), 106-112. https://doi.org/10.2113/gsecongeo.68.1.106.
Kesler, S.E., Chryssoulis, S.L.  Simon, G., 2002. Gold in porphyry copper deposits: its abundance and fate. Ore Geology Reviews 21(1-2), 103-124. https://doi.org/10.1016/S0169-1368(02)00084-7.
Kouzmanov, K., Pokrovski, G. S., Hedenquist, J. W., Harris, M., Camus, F., 2012. Hydrothermal controls on metal distribution in porphyry Cu (-Mo-Au) systems. Society of Economic Geolology Spececial Publication 16, 573-618. https://doi.org/10.1144/SP402.4.
Kouhestani, H., Rashidnejad-Omran, N., Rastad, E., Mohajjel, M., Goldfarb, R.J.  Ghaderi, M., 2014. Orogenic gold mineralization at the Chah Bagh deposit, Muteh gold district, Iran. Journal of Asian Earth Sciences 91, 89-106. https://doi.org/10.1016/j.jseaes.2014.04.027.
Kouhestani, H., Ghaderi, M., Chang, Z., & Zaw, K. (2015). Constraints on the ore fluids in the Chah Zard breccia-hosted epithermal Au–Ag deposit, Iran: Fluid inclusions and stable isotope studies. Ore Geology Reviews 65, 512-521. https://doi.org/10.1016/j.jseaes.2014.04.027.
Lecumberri Sanchez, P., 2013. Spatial and temporal evolution of fluids in hydrothermal ore deposits. Phd Thesis, Virginia Techology University.
Moncada, D., Baker, D.  Bodnar, R.J., 2017. Mineralogical, petrographic and fluid inclusion evidence for the link between boiling and epithermal Ag-Au mineralization in the La Luz area, Guanajuato Mining District, México. Ore Geology Reviews 89, 143-170. https://doi.org/10.1016/j.oregeorev.2017.05.024.
Pang, K.N., Chung, S.L., Zarrinkoub, M.H., Khatib, M.M., Mohammadi, S.S., Chiu, H.Y., Chu, C.H., Lee, H.Y.,  Lo, C.H., 2013. Eocene–Oligocene post-collisional magmatism in the Lut–Sistan region, eastern Iran: Magma genesis and tectonic implications. Lithos 180, 234-251. https://doi.org/10.1016/j.lithos.2013.05.009.
Rahim Souri, Y., Yaghoubpour, A., Modabberi, S., 2013. Geology studies and Carlin-type mineralization of Ag Darreh deposit, Takab, West Azerbaijan. Earth Sciences Quarterly, special issue 88(3), 42-53.
Ramezani, J.  Tucker, R.D., 2003. The Saghand region, central Iran: U-Pb geochronology, petrogenesis and implications for Gondwana tectonics. American Journal of Science 303(7), 622-665. https://doi.org/10.2475/ajs.303.7.622.
Richards, J.P., Wilkinson, D.  Ullrich, T., 2006. Geology of the Sari Gunay epithermal gold deposit, northwest Iran. Economic Geology 101(8), 1455-1496. https://doi.org/10.2113/gsecongeo.101.8.1455.
Richards, J.P., Spell, T., Rameh, E., Razique, A.  Fletcher, T., 2012. High Sr/Y magmas reflect arc maturity, high magmatic water content, and porphyry Cu±Mo±Au potential: Examples from the Tethyan arcs of central and eastern Iran and western Pakistan. Economic GSeology 107(2), 295-332. https://doi.org/10.2113/econgeo.107.2.295.
Richards, J.P., 2015. Tectonic, magmatic, and metallogenic evolution of the Tethyan orogen: From subduction to collision. Ore Geology Reviews 70, 323-345. https://doi.org/10.1016/j.oregeorev.2014.11.009.
Roedder, E., 1971. Fluid inclusion studies on the porphyry-type ore deposits at Bingham, Utah, Butte, Montana, and Climax, Colorado. Economic Geology 66(1), 98-118. https://doi.org/10.2113/gsecongeo.66.1.98.
Rusk, B.G., Reed, M.H.  Dilles, J.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. https://doi.org/10.2113/gsecongeo.103.2.307.
Saccani, E., Delavari, M., Beccaluva, L.,  Amini, S., 2010. Petrological and geochemical constraints on the origin of the Nehbandan ophiolitic complex (eastern Iran): Implication for the evolution of the Sistan Ocean. Lithos 117(1-4), 209-228. https://doi: 10.1016/j.lithos.2010.02.016.
Seedorff, E., Dilles, J.H., Proffett, J.M., Einaudi, M.T., Zurcher, L., Stavast, W.J., Johnson, D.A.  Barton, M.D., 2005. Porphyry deposits: Characteristics and origin of hypogene features. In: Hedenquist, J.W., Thompson, J.F.H., Goldfarb, R.J., Richards, J.P. (Eds.), One Hundredth Anniversary Volume. Society of Economic Geologists. pp. 251-298. https://doi.org/10.5382/AV100.10.
Shafaroudi, A.M., Karimpour, M.H.  Stern, C.R., 2015. The Khopik porphyry copper prospect, Lut Block, Eastern Iran: geology, alteration and mineralization, fluid inclusion, and oxygen isotope studies. Ore Geology Reviews 65, 522-544. https://doi.org/10.1016/j.oregeorev.2014.04.015.
Sillitoe, R.H., 2000. Gold-rich porphyry deposits: descriptive and genetic models and their role in exploration and discovery. In: Hagemann, S.G., Brown, P.E., (Eds.), Gold in 2000, SEG Reviews, 13.  pp. 315-345  https://doi.org/10.5382/Rev.13.09.
Sillitoe, R.H., 2010. Porphyry copper systems. Economic Geology 105(1), 3-41. https://doi.org/10.2113/gsecongeo.105.1.3.
Simon, G., Kesler, S.E., Essene, E.J.  Chryssoulis, S.L., 2000. Gold in porphyry copper deposits: Experimental determination of the distribution of gold in the Cu-Fe-S system at 400 to 700 C. Economic Geology 95(2), 259-270. https://doi.org/10.2113/gsecongeo.95.2.259.
Stampfli, G.M.  Borel, G.D., 2002. A plate tectonic model for the Paleozoic and Mesozoic constrained by dynamic plate boundaries and restored synthetic oceanic isochrons. Earth and Planetary Science Letters 196(1-2), 17-33. https://doi.org/10.1016/S0012-821X(01)00588-X.
Sun, W., Wang, J.T., Zhang, L.P., Zhang, C.C., Li, H., Ling, M.X., Ding, X., Li, C.Y.,  Liang, H.Y., 2017. The formation of porphyry copper deposits. Acta Geochimica 36, 9-15. https://doi.org/10.1007/s11631-016-0132-4.
Tirrul, R., Bell, I.R., Griffis, R.J.  Camp, V.E., 1983. The Sistan suture zone of eastern Iran. Geological Society of America Bulletin, 94(1), 134-150. https://doi.org/10.1130/0016-7606(1983)94%3C134:TSSZOE%3E2.0.CO,2.
Verdel, C., Wernicke, B.P., Ramezani, J., Hassanzadeh, J., Renne, P.R.  Spell, T.L., 2007. Geology and thermochronology of Tertiary Cordilleran-style metamorphic core complexes in the Saghand region of central Iran. Geological Society of America Bulletin 119(7-8), 961-977. https://doi.org/10.1130/B26102.1.
Van den Kerkhof, A.M.  Hein, U.F., 2001. Fluid inclusion petrography. Lithos 55(1-4), 27-47. https://doi.org/10.1016/S0024-4937(00)00037-2.
Vila, T.  Sillitoe, R.H., 1991. Gold-rich porphyry systems in the Maricunga belt, northern Chile. Economic Geology 86(6), 1238-1260. https://doi.org/10.2113/gsecongeo.86.6.1238.
Zarrinkoub, M.H., Pang, K.N., Chung, S.L., Khatib, M.M., Mohammadi, S.S., Chiu, H.Y.  Lee, H.Y., 2012. Zircon U–Pb age and geochemical constraints on the origin of the Birjand ophiolite, Sistan suture zone, eastern Iran. Lithos 154, 392-405. https://doi.org/10.1016/j.lithos.2012.08.007.