Geology and Geochemistry of Cu Mineralization in the Dehmadan and Darreh-Yas indices, Charmahal va Bakhtiari Province


1 Department of Geology, Faculty of Earth Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran

2 Research Institute for Earth Sciences, Geological Survey and Mineral Exploration of Iran, Tehran, Iran


Mashayekh area is located in Charmahal and Bakhtiari province and is structurally located in the high Zagros belt. This region is characterized by two mining districts, namely, the Dehmadan and the Darreh-Yas, approximately two kilometers apart. The most mineralization is associated with organic-bearing carbonate rocks in the Dehmadan deposit. The presence of Do-ab salt dome and Ab-Vanak reverse fault in around of the study area have been resulted in changing the salinity, Eh, pH and movement of ore forming fluids. The geochemical results represent negative Ce and Eu anomalies, Light Rare Earth elements (LREE) enrichment relative to Heavy Rare Earth Elements (HREE) in the Dehmadan deposit that the features are analogous to that of central African Zambian belt sedimentary copper deposits. Darreh-Yas deposit also shows weak negative Ce anomaly and HREE enrichment relative to LREE. In general, the results indicate that metals of old units have been leached by high saline brines with oxic conditions and entered into sedimentary basins. Then, the reaction of ore-forming fluid with organic-bearing carbonate rocks lead to ore deposition in a reduced condition. Finally, the ore has been undergone by late-stage supergene and weathering processes.


Ahankoub, M., 2009. Petrological and Geochemical investigation of Naghān Copper Ore Deposit (Ardal), Research Project. Payame Noor University of Shahrekord, p. 113.
Alavi, M.,1994. Tectonics of the Zagros orogenic belt of Iran: newdata and interpretations. Tectonophysics 229, 211–238.
Alavi, M., 2004. Regional stratigraphy of the Zagros fold-thrust belt of Iran and its pro foreland evolution. American Journal of Science 304, 1–20.
Alavi, M., 2007. Structure of the Zagros Fold-Thrust Belt in Iran. American Journal of Science 307, 1064–1095.
Bau, M., Dulski, P., 1996. Distribution of yttrium and rare-earth elements in the Penge and Kuruman iron-formations, Transvaal Supergroup, South Africa. Precambrian Research 79, 37–55.
Bhatia, M.R., Crook, K.A.M., 1986. Trace element characteristics of graywackes and tectonic discriminiation of sedimentary basins. Contributions to Mineralogy and Petrology 92, 181-193.
Bornhorst, T.J., Williams, W.C., 2013. The Mesoproterozoic Copperwood sedimentary rock-hosted stratiform copper deposit, Upper Peninsula, Michigan. Economic Geology 108, 1325-1346.
Boynton, W.V., 1984. Geochemistry of the rare earth elements: meteorite studies. In: Henderson. P. Rare Earth Element geochemistry. (Ed.). Elsevier, Amsterdam, pp. 114.
Cailteux, J.L.H., Kampunzu, A.B., Lerouge, C., Kaputo, A.K., Milesi, J.P., 2005. Genesis of sediment-hosted strati-form copper-cobalt deposits, central African Copper belt. Journal of African Earth Sciences 42, 134–158.
Condie, K.C., Wronkiewicz, D.S., 1990. The Ce/Th ratio in Precambrian pelites from the Kaapvaal Craton as an index of cratanic evolution. Earth and Planetary Science Letters 97, 256-267.
Cox, D.P., Bernstein, L.R., 1986. Descriptive model of Kipushi Cu-Pb-Zn, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 227.
Ehsan Bakhshi Kermani, M.H., Rahimzadeh, F., Qomishi, A., Jamshidi, KH., 1996. Map 1: 100000 Ardal, Geological Survey and Mineral Exploration of Iran.
Ghorbani, M., 2007. Economic Geology of Mineral Deposits and Natural Resources of Iran, 1st edition, Arian Zamin Publishers, p. 492.
Hayes, T.S., 1990. A preliminary study of thermometry and metal sources of the Spar Lake stratabound copper-silver deposit, Belt Supergroup, Montana, U.S. Geological Survey 90-484, p. 30.
Hitzman, M., Kirkham, R., Broughton, D., Thorson, J., Selley, D., 2005. The sediment hosted stratiform copper ore systemEconomic Geology, 609–642.
Hitzman, M.W., Selley, D., Bull, S., 2010. Formation of sedimentary rock-hosted stratiform copper deposits through Earth history. Economic Geology 105, 627–639.
Hongo, Y., Nozaki, Y., 2001. Rare earth element geochemistry of hydrothermal deposits and Calyptogena shell from the Iheya Ridge vent field, Okinawa Trough. Geochemical journal 35, 347–354.
Jones, B., Manning, D.C., 1994. Comparison of geochemical indices used for the interpretation of paleo-redox conditions in Ancient mudstones. Chemical Geology 111, 111-129.
Kirkham, R.V., 1989. Distribution, settings, and genesis of sediment-hosted stratiform copper deposits. In: Boyle, R.W., Brown, A.C., Jefferson, C.W., Jowett, E.C., Kirkham, R.V. (Eds). Sediment-hosted stratiform copper deposits. Geological Association of Canada, Special Paper 36, p. 3–38.
McLennan, S.M., 1989. Rare earth elements in sedimentary rocks: influence of provenance and sedimentary processes. Geochemistry and mineralogy of rear earth elements. Review in Mineralogy 21, 169-200.
McLennan, S.M., Taylor, S.R., 1991. Sedimentary rocks and crustal evolution revisited: tectonic setting and secular trends. The Journal of Geology 99, 1-21.
Nesbitt, H.W., Young, G.M., 1982. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites, Nature 299, 715-717.
Nesbitt, H.W., Young, G.M., 1989. Formation and diagenesis of weathering profile, The Journal of Geology 97, 129-174.
Norman, M.D., De Deckker, P., 1990. Trace elements in lacustrine and marine sediments: a case study from gulf of Carpentaria, northern Australia. Chemical geology 82, 299-318.
Nowecki, J.P., 2014. Tracing seawater evaporation and its role in the formation of sediment-hosted stratiform copper deposits (Doctoral dissertation, University of Southampton).
Ohmoto, H., 1986. Stable isotope geochemistry of ore deposits. In: Valley, J.W., Taylor, H.P., O’Neil, J.R. (Eds). Stable isotopes in high temperature geological processes. Reviews in Mineralogy 16.
Pirajno, F., Mernagh, T.P., Huston, D., Creaser, R.A. and Seltmann, R., 2016. The Mesoproterozoic Abra polymetallic sedimentary rock-hosted mineral deposit, Edmund Basin, Western Australia. Ore Geology Reviews 76, 442-462.
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 Geology 107, 295-332.
Rimmer, S.M., 2004. Geochemical paleoredox indicators in the Devonian– Mississippian black shales, central Appalachian Basin (USA). Chemical Geology 206, 373–391.
Roberts, S., Palmer, M.R., Cooper, M.J., Buchaus, P., Sargent, D., 2009. REE and Sr isotope characteristics of carbonate within the CuCo mineralized sedimentary sequence of the Nchanga Mine, Zambian Copper belt. Mineralium Deposita 44, 881–891.
Rollinson, H., 1996. Using geochemical data: evaluation, presentation, interpretation. Longman Scientific and Technical, John Wiley and Sons, New York.
Taylor, C.D., Causey, J.D., Denning, P.D., Hammarstrom, J.M., Hayes, T.S., Horton, J.D., Kirschbaum, M.J., Parks, H.L., Wilson, A.B., Wintzer, N.E., Zientek, M.L., 2013. Descriptive models, grade-tonnage relations, and databases for the assessment of sediment-hosted copper deposits-With emphasis on deposits in the Central African Copperbelt, Democratic Republic of the Congo and Zambia, U.S. Geological Survey, Scientific Investigations Report 2010–5090–J, 154.
Toth, J.R., 1980. Deposition of submarine crusts rich in manganese and iron. Geological Society of America Bulletin 91, p. 44– 54.
Webb, G.E., Kamber, B.S., 2000. Rare earth elements in Holocene reefal microbialites; a new shallow seawater proxy, Geochimica et Cosmochimica Acta 64, 1557–1565.
Zarasvandi, A., Charchi, A., Carranza, E.J.M., Alizadeh, B., 2008. Karst bauxite occurrence in the Zagros Mountain Belt, Iran. Ore Geology Reviews 34, 521- 553.
Zarasvandi, A., Lentz, D., Rezaei, M., Pourkaseb, H., 2013. Genesis of the Nasirabad manganese occurrence, Fars province, Iran: Geochemical evidences. Geochemistry 73, 495-508.
Zhao, X.F., Zhou, M.F., Li, J.W. and Qi, L., 2013. Late Paleoproterozoic sedimentary rock-hosted stratiform copper deposits in South China: their possible link to the supercontinent cycle. Mineralium Deposita 48, 129-136.