Mineralization, structure, texture and genesis of sediment-hosted Chehrabad Pb–Zn–Cu deposit, NW Zanjan

زمین شناسی اقتصادی

Article 3, Volume 12, Issue 2 - Serial Number 25, 2020, Pages 177-202   

Document Type: Research Article

DOI: 10.22067/econg.v12i2.74819

Authors

Ali Rajabzadeh; Hossein Kouhestani^* ; Mir Ali Asghar Mokhtari; Afshin Zohdi

University of Zanjan

Abstract

Introduction
Sediment-hosted stratabound copper (SSC) deposits are bodies of disseminated, cementing, and lesser veinlet hosted copper minerals that are peneconformable with their sedi­mentary or metasedimentary host rocks (Hayes et al., 2015). These deposits have been termed sediment hosted stratiform Cu, sedimentary rock-hosted stratiform Cu, Cu shale, Cu sandstone, cupriferous sandstones, sandstone Cu, red-bed Cu, Kupferschiefer type Cu, marine paralic type Cu, reduced-facies Cu, or Revett Cu deposits (Cox et al., 2003, 2007; Hitzman et al., 2005; Hayes et al., 2015). SSC deposits occur in three subtypes divided by host lithology and the corresponding type of reductant that precipitated sulfur and Cu from warm, oxidized, metals-transporting, sedimentary brines. These types are as follows: (1) reduced-facies type; (2) sandstone-type (Revett); and (3) red-bed type. These deposits have been formed during the middle-late Paleoproterozoic to Tertiary.
There are several SSC deposits in the Avaj Zanjan Tabriz Khoy area in the northwestern Iran that are hosted by grey sandstone units of the Upper Red Formation (URF). The Tasouj, Tazekand, Nahand Ivand, Ortasou, Chehrabad, Halab, Zagelou and Avaj are the main important deposits in this area. These deposits predominantly consist of bedding-parallel replacement and disseminated Cu–Pb–Zn sulfides, roughly concordant with the stratification. The average Cu, Pb and Zn content of these deposits are ~1.5, 2 and ~1 wt.%, respectively.
Apart from small scale geological maps of the area, i.e., 1:250,000 geological maps of Takab (Alavi and Omidi, 1976), 1:100,000 geological maps of Mahneshan (Lotfi, 2001) and a number of unpublished Pb–Zn–Cu exploration reports, no other work has been reported prior to this research study on Pb–Zn–Cu mineralization at Chehrabad. The present paper provides an overview of the geological framework and the mineralization characteristics of the Chehrabad deposit with an application to ore genesis. Identification of these characteristics can be used as an exploration model for this type of Pb–Zn–Cu mineralization in this area and elsewhere.
 
Materials and methods
Detailed field work has been carried out at different scales in the Chehrabad area. During the field works, detailed stratigraphic sections were measured, sampled and described. In addition, the color of the sandstone layers and the presence of fossil woods were scanned during the field work. About 23 polished thin and thin sections from host rocks and mineralized layers were studied by conventional petrographic and mineralogic methods at the University of Zanjan in Iran.
 
Results and Discussion
The Pb–Zn–Cu deposit at Chehrabad, 75 km northwest of Zanjan, is located in the Central Iranian zone. Rock units exposed in this area belong to the URF, and consist of alternations of red and green marl intercalated with red to grey, medium- to thick-bedded sandstone. In this area, URF has 980 m thickness and consists of four main parts. These parts, from bottom to top, consist of 1- alternation of gypsiferous green marls along with gypsium and salt layers (235 m), 2- red marls intercalated with grey and red sandstones (445 m), 3- alternation of red and green marls intercalated with sandstones (145 m), and 4- alternation of green marls and green siltstones (155 m). The Pb–Zn and Cu mineralization in the Chehrabad deposit has occurred in grey sandstone units of the second part of the URF. Mineralization has often been formed around and within the fragments of the plant fossils, in the form of disseminated and the solution seems to have been sulfides. Based on field studies, mineralization at the Chehrabad deposit has occurred in two horizons of reduced-grey sandstones, H-A and H-B, with about 4 and 6 m thickness and about 200 and 1000 m length, respectively. These horizons contain red oxidized zone, bleached zone and mineralized reduced zone with the latter being located within the bleached zone.
The red oxidized zone consists of red marl and sandstone layers containing iron oxides which are located adjacent to the reduced horizons. The red color of this zone has been caused by the presence of iron oxides around the grains. The oxidized pyrite crystals are the main important minerals in this zone. The bleached zone is a part of sandstone sequences that have undergone changes in their color due to the alteration processes. Grey and green colors in this zone have occurred due to the presence of organic materials and diagenetic pyrites. Mineralization in the reduced zone has occurred within the organic materials bearing bleached zones. Plant debris, plant fossils, diagenetic pyrites and permeability of host rocks have the most important roles for the Pb-Zn and Cu mineralization at the Chehrabad deposit.
Galena, sphalerite, chalcocite, pyrite and chalcopyrite along with minor Ag-bearing sulfides (mckinstryite, stromeyrite) are the main ore minerals at the Chehrabad deposit. Cerussite, malachite, azurite, covellite, atacamite, vanadinite, and goethite are formed during supergene processes. Disseminated and cemented textures along with lens-shaped, solution seems, replacement, vein-veinlet, and framboidal are the main ore textures at the Chehrabad deposit. Based on the tectonic setting, host rock, geometry, presence of plant fossils, ore structure and texture and mineralogy, it can be concluded that the Chehrabad deposit is a sediment-hosted Redbed type Cu deposit.
 
References
Cox, D.P., Lindsey, D.A, Singer, D.A. and Diggles, M.F., 2007. Sediment-hosted copper deposits of the world-deposit models and database. U.S. Geological Survey, Canada, Open-file report 03-107, 50 pp.
Cox, D.P., Lindsey, D.A., Singer, D.A., Moring, B.C. and Diggles, M.F., 2003. Sediment-hosted copper deposits of the world-deposit models and database. U.S. Geological Survey, Canada, open-file report 03-107, 53 pp.
Hayes, T.S., Cox, D.P., Piatak, N.M. and Seal, R.R., 2015. Sediment-hosted stratabound copper deposit model. U.S. Geological Survey, Virginia, 147 pp.
Hitzman, M., Kirkham, R., Broughton, D., Thorson, J. and Selley, D., 2005. The sediment-hosted stratiform copper ore system. In: J.W. Hedenquist, J.F.M. Thompson, R.J. Goldfarb and J.P. Richards (Editors), One Hundered Anniversary volume. Economic Geology, Littleton, pp. 609–612.

Keywords

Sediment-hosted Cu mineralization; Redbed type; Upper Red Formation; Chehrabad; Zanjan

References

Adkins, A.R., 1993. Geology of the Montanore stratabound Cu-Ag deposit, Lincoln and Sanders Counties, Montana. Belt Symposium III, Program and Abstracts, Whitefish, Montana, USA.

Aghanabati, A., 2004. Geology of Iran. Geological Survey of Iran, Tehran, 606 pp. (in Persian)

Alavi, M. and Omidi, M., 1976. Geological map of Takab, scale 1:250,000. Geological Survey of Iran.

Alderton, D.H.M., Pearce, J.A. and Potts, P.J., 1980. Rare earth element mobility during granite alteration: evidence from south-east England. Earth and Planetary Science Letters, 49(1): 149–165.

Annels, A.E., 1989. Ore genesis in the Zambian Copper belt, with particular reference to the northern sector of the Chambishi basin. In: R.W. Boyle, A.C. Brown, C.W. Jefferson, E.C. Jowett and R.V. Kirkham (Editors), Sediment-hosted Stratiform Copper Deposits. Geological Association of Canada, Special Paper 36, Canada, pp. 427–452.

Avila-Santos, W., 1990. Origin of the copper at Corocoro, Bolivia. In: L. Fontbote, G.C. Amstitz, M. Cardozo, E. Cedillo and J. Frutos (Editors), Stratabound Ore Deposits of the Andes. Springer-Verlag, Berlin, pp. 659–670.

Azaraien, H., Shahabpour, J. and Aminzadeh, B., 2017. Metallogenesis of the sediment-hosted stratiform Cu deposits of the Ravar Copper Belt (RCB), Central Iran. Ore Geology Reviews, 81(1): 369–395.

Azizi, H., Hosseinzadeh, M.R., Moayyed, M. and Siahcheshm, K., 2018. Geology and geochemistry of the sediment-hosted stratabound red bed-type Cu-Pb (Zn-Ag) mineralization in the Dozkand-Moshampa area, NW Zanjan, Iran. Neues Jahrbuch für Mineralogie-Abhandlungen (Journal of Mineralogy and Geochemistry), 195(2): 123–143.

Ballato, P., Cifelli, F., Heidarzadeh, G., Ghassemi, M.R., Wickert, A., Hassanzadeh, J., Dupont-Nivet, G., Balling, P., Sudo, M., Zeilinger, G., Schmitt, A., Mattei, M. and Strecker, M., 2016. Tectono-sedimentary evolution of the northern Iranian Plateau: insights from middle–late Miocene foreland basin deposits. Basin Research, 29(12):417–446.

Brown, A.C., 1984. Alternative sources of metals for stratiform copper deposits. Precambrian Research, 25(1–3): 61–74.

Brown, A.C., 1997. World-class sediment-hosted stratiform copper deposits: characteristics, genetic concepts and metallotects. Australian Journal of Earth Sciences, 44(3):317–328.

Brown, A.C., 2003. Redbeds: Source of metals for sediment-hosted stratiform copper, sandstone copper, sandstone lead, sandstone uranium vanadium deposits. In: D.R. Lentz (Editor), Geochemistry of sediments and sedimentary rocks: evolutionary considerations to mineral deposit forming environments. Geological Association of Canada, GeoText, Canada, pp. 121–133.

Chan, M.A., Bowen, B.B., Parry, W.T., Ormö, J. and Komatsu, G., 2005. Red rock and red planet diagenesis: Comparisons of Earth and Mars concretions. GSA Today, 15(8): 4–10.

Cox, D.P., Lindsey, D.A, Singer, D.A. and Diggles, M.F., 2007. Sediment-hosted copper deposits of the world-deposit models and database. U.S. Geological Survey, Canada, Open-file report 03-107, 50 pp.

Cox, D.P., Lindsey, D.A., Singer, D.A., Moring, B.C. and Diggles, M.F., 2003. Sediment-hosted copper deposits of the world-deposit models and database. U.S. Geological Survey, Canada, open-file report 03-107, 53 pp.

Daliran, F., Pride, K., Walther, W., Berner, Z.A. and Bakker, R.J., 2013. The Angouran Zn (Pb) deposit, NW Iran: evidence for a two stage, hypogene zinc sulfide–zinc carbonate mineralization. Ore Geology Reviews, 53: 373–402.

Dokuz, A., Tanyolu, E. and Genc, S., 2005. A mantle and a lower crust derived bimodal suite in the Yusufeli Artvin area, NE Turkey: Trace element and REE evidence for subduction-related rift origin of Early Jurasic Demirkent intrusive complex. International Journal of Earth Sciences, 95(3): 370–394.

Durieux, C.G. and Brown, A.C., 2007. Geological context, mineralization, and timing of the Juramento sediment-hosted stratiform copper-silver deposit, Salta district, northwestern Argentina. Mineralium Deposita, 42(8): 879–899.

Ebrahimi, M., Kouhestani, H. and Shahidi, E., 2015. Investigation of type and origin of iron in the Mesgar occurrence, south of Zanjan, using by petrology, mineralogy and geochemistry data. Journal of Economic Geology, 7(1): 111–127. (in Persian with English abstract)

Enayati Kolaie, S., Yazdi, M. and Mokhtari, M.A.A., 2016. Geology, mineralogy and genesis of stratiform Cu mineralization in the Tazeh-Kand area, Northeast of Tabriz. Scientific Quarterly Journal, GEOSCIENCES, 25(99): 195–208. (in Persian with English abstract)

Flint, S.S., 1989. Sediment-hosted stratabound copper deposits of the Central Andes. In: R.W. Boyle, A.C. Brown, C.W. Jefferson, E.C. Jowett and R.V. Kirkham (Editors), Sediment-hosted stratiform copper deposits. Geological Association of Canada, Special Paper 36, Canada, pp. 371–400.

Folk, R.L., 1980. Petrology of sedimentary Rocks. Austin, Texas, Hemphill, 159 pp.

Gablina, I.F., 1981. New data on formation conditions of the Dzhezkazgan copper deposit. International Geology Review, 23(11): 1303–1311.

Garlick, W.S., 1989. Mineralization controls and source of metal in the Lufillian fold belt, Shaba (Zaire), Zambia and Angola: A discussion. Economic Geology, 84(4): 966–968.

Ghasemlou, A., Kouhestani, H., Mokhtari, M.A.A. and Zohdi, A., 2016. Geological characteristic and mineralization of Hamzelou copper ore deposit, Northwest of Zanjan. 35th Symposium of Geosciences, Geological Survey of Iran, Tehran, Iran. (in Persian with English abstract)

Ghasemlou, A., Kouhestani, H., Mokhtari, M.A.A. and Zohdi, A., 2017. Stratigraphy and petrographical composition of the Upper Red Formation sandstone in Hamzelou Cu deposit, Northwest of Zanjan. 3th Congress Sedimentology of Iran, Tehran, Iran. (in Persian with English abstract)

Guilbert, J. and Park, Ch., 1997. The Geology of Ore deposits, W.H. Freeman and Company Publication, New York, 985 pp.

Haghighi, A., Nabatian, Gh., Kouhestani, H., Azimzadeh, A.M. and Zohdi, A., 2016. Geochemistry of the main oxides hosted Ortasu Pb-Zn deposite, northwest Zanjan. 8th Congress of Economic Geology of Iran, University of Zanjan, Zanjan, Iran. (in Persian with English abstract)

Haghighi, A., Nabatian, Gh., Kouhestani, H., Azimzadeh, A.M. and Zohdi, A., 2019. Mineralization, mineralogy, structure, texture and genesis of Ortasu Pb-Zn deposit, NW Zanjan. Journal of Economic Geology, 11(3): 359–386. (in Persian with English abstract)

Hayes, T.S., Cox, D.P., Piatak, N.M. and Seal, R.R., 2015. Sediment-hosted stratabound copper deposit model. U.S. Geological Survey, Virginia, 147 pp.

Hitzman, M., Kirkham, R., Broughton, D., Thorson, J. and Selley, D., 2005. The sediment-hosted stratiform copper ore system. In: J.W. Hedenquist, J.F.M. Thompson, R.J. Goldfarb and J.P. Richards (Editors), One Hundered Anniversary volume. Economic Geology, Littleton, pp. 609–612.

Hitzman, M.W., Selley, D. and Bull, S., 2010. Forma‌tion of sedimentary rock-hosted stratiform copper deposits through earth history. Economic Geology, 105(3): 627–639.

Jamalipour, S., 2015. Mineralogy and geochemistary of host rock and Pb ore in the Chaerlanghoosh deposit. M.Sc. Thesis, University of Zanjan, Zanjan, Iran, 125 pp. (in Persian with extended English abstract)

Jowett, E.C., 1989. Effects of continental rifting on location and genesis of stratiform copper–silver deposits. In: R.W. Boyle, A.C. Brown, C.W. Jefferson, E.C. Jowett and R.V. Kirkham (Editors), Sediment-hosted stratiform copper deposits. Geological Association of Canada, Special Paper 36, Canada, pp. 53–66.

Jowett, E.C., Rydzewski, A. and Jowett, R.J., 1987. The Kupferschiefer Cu-Ag ore deposits in Poland: A reappraisal of the evidence of their origin and presentation of a new genetic model. Canadian Journal of Earth Sciences, 24(10): 2016–2037.

Karami, M., Ebrahmi, M. and Kouhestani, H., 2016. Loulak-Abad occurrence, NW Zanjan: metamotphosed and deformed type of volcano-sedimentary deposit in the Central Iranian Zone. Journal of Economic Geology, 8(1): 93-115. (in Persian with English abstract)

Karimi, M., 2012. Final Exploration Report of Cu-Pb in Chehrabad area. Industry, Mine and Trade Organization of Zanjan, Zanjan, 178 pp. (in Persian)

Khodabandeh, A.A., Faridi, M. and Amini Azar, R., 1998. Geologic map of Miyaneh, scale 1:100,000. Geological Survey of Iran, Iran.

Kirkham, R.V., 1989. Distribution, setting and genesis of sediment-hosted stratiform copper deposits. In: R.W. Boyle, A.C. Brown, C.W. Jefferson, E.C. Jowett and R.V. Kirkham (Editors), Sediment-hosted stratiform copper deposits. Geological Association of Canada, Special Paper 36, Canada, pp. 3–38.

Kirkham, R.V., 1996. Sediment-hosted copper. In: O.R. Eckstrand, W.D. Sinclair and R.I. Thorpe (Editors), Geology of Canadian Mineral Deposit Types. Geological Association of Canada, Canada, pp. 223–240.

Lotfi, M., 2001. Geologic map of Mahneshan, scale 1:100,000. Geological Survey of Iran, Iran.

Love, L.G. and Brockley, H., 1973. Peripheral radial texture in framboids of poly-framboidal pyrite. Fortschritte der Mcneralogie, 50(3): 264–269.

MacIntyre, T.J., 2005. Fault-controlled hydrocarbon-related bleaching and sediment-hosted copper mineralization of the Jurassic Wingate sandstone at the Cashin Mine, Montrose County, Colorado. Unpublished M.Sc. Thesis, Colorado School of Mines, Colorado, United State, 360 pp.

MacIntyre, T.J., Thorson, J.P. and Hitzman, M.W., 2004. Setting the stage for sediment-hosted copper: Fault-related hydrocarbon bleaching and copper ore at the Cashin mine, Montrose County, Colorado. 36th Denver Annual Meeting, Geological Society of America, Denver, USA.

Mahdavi, A., Rastad, A. and Hosseini Barzy, M., 2011. Mineralogy, structure and texture and genesis of sedimentary diagenetic Cu Markeshe, Redbed type, in the Garedu Red Formation, Jurassic, south of Central Iran. Scientific Quarterly Journal, GEOSCIENCES, 21(81): 81–92. (in Persian with English abstract)

Maleki Kahangi, M., 2016. Mineralogy, geochemistry and mineralization of sedimentary copper deposit in Halab area, Zanjan. Unpublished M.Sc. Thesis, Shahid Beheshti University, Tehran, Iran, 156 pp. (in Persian with English abstract)

Nabatian, Gh., Ghaderi, M., Rashid-Nejad Omran, N. and Daliran, F., 2010. Geochemistry and origin of Sorkheh-Dizaj iron oxide- apatite deposit, SE Zanjan. Journal of Economic Geology, 1(1): 19-46. (in Persian with English abstract).

Oszczepalski, S., 1999. Origin of the Kupferschiefer polymetallic mineralization in Poland. Mineralium Deposita, 34(5-6): 599–613.

Parry, W.T., Chan, M.A. and Beitler, B., 2004. Chemical bleaching indicates fluid flow in sandstone deformation bands. American Association of Petroleum Geologists Bulletin, 88(2): 175–191.

Rahimi, R., 2016. Mineralogy and formation of copper in Ghezeljeh region. Unpublished M.Sc. Thesis, Shahid Beheshti University, Tehran, Iran, 196 pp. (in Persian English abstract)

Rajabpour, S., Abedini, A., Alipour, S., Lehmann, B., Jiang, S.Y., 2017. Geology and geochemistry of the sediment-hosted Cheshmeh-Konan Redbed-type copper deposit, NW Iran. Ore Geology Reviews, 86: 154–171.

Rajabzadeh, A., 2018. Geology, geochemistry and genesis of sediment-hosted Chehrabad Pb-Zn mineralization (NE Mahneshan). Unpublished M.Sc. Thesis, University of Zanjan, Zanjan, Iran. 162 pp. (in Persian with English abstract)

Rajabzadeh, A., Kouhestani, H., Mokhtari, M.A.A. and Zohdi, A., 2016. Mineralization, structure and textures and mineralography of Chehrabad Cu-Pb-Zn deposit, northwest of Zanjan. 35th Symposium of Geosciences, Geological Survey of Iran, Tehran, Iran. (in Persian with English abstract)

Rajabzadeh, A., Kouhestani, H., Mokhtari, M.A.A. and Zohdi, A., 2020. Petrography and geochemistry of major and trace elements of the Upper Red Formation at Chehrabad Pb-Zn deposit, northwest of Zanjan, implication for provenance and tectonic setting. Scientific Quarterly Journal, GEOSCIENCES. (in Persian with English abstract)

Rose, A.W., 1976. The effect of cuprous chloride complexes in the origin of red-bed copper and related deposits. Economic Geology, 71(6): 1036–1048.

Sadati, S.N., 2016. Mineralogy, geochemistry and genesis of Cu deposit in sedimentary rocks in the north of Tabriz, (East Azarbayjan province), NW Iran. Unpublished Ph.D. Thesis, Shahid Beheshti University, Tehran, Iran, 170 pp. (in Persian with English abstract)

Sadati, S.N., Yazdi, M., Mao, J., Behzadi, M., Adabi, M.H., Lingang, X., Zhenyu, C. and Moktari, M.A.A., 2016. Sulfide mineral chemistry investigation of sediment-hosted stratiform copper deposits, Nahand-Ivand area, NW Iran. Ore Geology Reviews, 72(1): 760–776.

Salehi, T., Ghaderi, M. and Rashid-Nejad Omran, N., 2011. Mineralogy and geochemistry of Rear Earth Elements in the Gomish-Tappeh Zn-Pb-Cu (Ag) deposit, SW Zanjan. Journal of Economic Geology, 2(2): 235-254. (in Persian with English abstract)

Sephri Rad, R. and Fathjo, D., 2010. Exploration report of sedimentary copper mineralization in south Zanjan. Geological Survey of Iran, Tehran, 150 pp. (in Persian)

Shakouri, N., Nabatian, Gh., Kouhestani, H. and Zohdi, A., 2016. Mineralization, structure and textures and mineralography of Sari Kand Pb-Zn deposit, Northwest of Zanjan. 35th Symposium of Geosciences, Geological Survey of Iran, Tehran, Iran. (in Persian with English abstract)

Subias, I., Fanlo, I. and Mateo, J., 2003. A model for the diagenetic formation of sandstone-hosted copper deposits in Tertiary sedimentary rocks, Aragon, NE Spain: S/C ratios and sulfur isotope systematic. Ore Geology Reviews, 23(1-2): 55–70.

Sun, S.S. and McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. In: A.D. Saunders and M.J. Norry (Editors), Magmatism in the Ocean Basins. Geological Society of London, Special Publication 42, London, pp. 313–345.

Taylor, S. and McLennan, S., 1985. The continental crust: Its composition and evolution. Blackwell, Oxford, 312 pp.

Thompson, R.N., 1982. Magmatism of the British Tertiary province. Scottish Journal of Geology, 18(1): 49–107.

Thorson, J.P., 2004. Paradox Basin sandstone-hosted copper deposits generated by two episodes of basinal fluid expulsion. 36th Denver Annual Meeting, Geological Society of America, Denver, USA.

Walker, T.R., 1989. Application of diagenetic alterations in red beds to the origin of copper in stratiform copper deposits. In: R.W. Boyle, A.C. Brown, W. Jefferson, E.C. Jowett and R.V. Kirkham (Editors), Sediment-hosted stratiform copper deposits. Geological Association of Canada, Special Paper 36, Canada, pp. 85‒96.

Wang, Q., Wyman, D.A., Xu, J.F, Zhao, Z.H., Jian, P., Xiong, X.L., Bao, Z.W., Li, C.F. and Bai, Z.H., 2006. Petrogenesis of Cretaceous adakitic and shoshonitic igneous rocks in the Luzong area, Anhui province (Eastern China): Implications for geodynamics and Cu-Au mineralization. Lithos, 89(3–4): 424–446.

Whitney, D.L. and Evans, B.W., 2010. Abbreviations for names of rock-forming minerals. American Mineralogist, 95(1): 185–187.

Woodward, K.H., Kaufman, W.H., Schumacher, O.L. and Talbott, L.W., 1974. Stratabound copper deposits in Triassic sandstone of Sierra Nacimiento, New Mexico. Economic Geology, 69(1): 108‒120.