Mineralogical and Geochemical Characteristics of Serpentinite-Derived Ni-Bearing Laterites from Fars Province, Iran: Implications for the Lateritization Process and Classification of Ni-Laterites
Nickel-bearing laterites occur as two parallel belts along Sedimentary Zagros Orogenic (SZO) and Metamorphic Sanandaj-Sirjan (MSS) petrostructural zones, Fars Province, south Iran. An undisturbed vertical profile of these laterites includes protolith, saprolite, clay, and oxide horizons from base to top. Highly serpentinized harzburgite with relicts of olivine and orthopyroxene is regarded as the source rock. The laterites are unusual in lacking a significant saprolite zone with little development of Ni-silicates. Hematite, saponite, dolomite, smectite and clinochlore increase, while calcite, olivine, lizardite and chrysotile decrease from saprolite to oxide zones. Smectite and clinochlore with minor calcite are the major minerals in clay zone. Contacts of different horizons in laterite profiles are gradual and characterized by a decrease in Mg concentration ranging from 18.1 to 9.3 wt.% in oxide and saprolite, respectively. The maximum Ni concentration is 0.34 wt.% (NiO) in the base of the oxide zone, and goethite is the major Ni-bearing phase. From saprolite to oxide horizons, Al2O3, K2O, TiO2, and CaO decrease, while SiO2, MnO, NiO, and Fe2O3 increase. Silica content reaches up to 45 wt.% in the upper part of the soil profile. There is a decrease in pH (8.44-8.17) and an increase in organic matter (0.28-0.59 wt.%) from base to top of the soils. The studied laterites are classified in the oxide clans which were derived from ophiolite ultramafic rocks under Mediterranean climate conditions.
 M. J. Wilson, “Weathering of the primary rock-forming minerals: processes, products and rates”. Clay Miner., vol. 39, 2004, pp. 233–266.
 J. Garnier, C. Quantin, E. Guimaraes, V. K. Garg, E.S. Martins, T. Becquer, “Understanding the genesis of ultramafic soils and catena dynamics in Niquelandia, Brazil”. Geoderma, vol. 151, 2009, pp. 204–214.
 M. Elias, “Nickle laterite deposits-geological overview, resources and exploitation, in giant ore deposit: characteristics, genesis and exploration”. Centre Ore Deposit Res., Univ. Tasmania, Spec. Pub. vol. 4, 2002, pp. 205–220.
 S. A. Gleeson, R. J. Herrington, J. Durango, C. A. Velazquez, “The mineralogy and geochemistry of the Cerro Matoso S. A. Ni laterite deposit, Montelibano, Colombia”. Econ. Geol. vol. 99, 2004, pp. 1197–1213.
 A. D. Dalvi, W. G. Bacon, R. C. Osborne, “Past and future of nickel laterite projects”. In: Imrie, W. P., Lane, D. M. (Eds.), International Nickel Laterite Symposium TMS. 133 Annual Meeting and Exhibition, Charlotte, N. Carolina, 2004, pp. 23–50.
 G. M. Mudd, “Global trends and environmental issues in nickel mining: sulfides versus laterites”. Ore Geol. Rev. vol: 38, 2010, pp. 9–26.
 C. W. Butt, D. Cluzel, “Laterite nickel ore deposits: weathered serpentinites”. Elements. vol. 9, 2013, pp. 123–128.
 P. Freyssinet, C. R. M. Butt, R. C. Morris, P. Piantone, “Ore-forming processes related to lateritic weathering”. Society of Economic Geologists, Inc. Economic Geology 100th Anniversary Volume, 2005, pp. 681–722.
 J. F. Lewis, G. Draper, J. A. Proenza, J. Espaillat, J. Jimenez, “Ophiolite-related ultramafic rocks (Serpentinites) in the Caribbean Region: a review of their occurrence, composition, origin, and emplacement and Ni-laterite soils formation”. Geol. Acta, vol. 4, 2006, pp. 237–263.
 M. A. Wells, E. R. Ramanaidou, M. Verrall, C. Tessarolo, “Mineralogy and crystal chemistry of ‘‘garnierites’’ in the Goro lateritic nickel deposit, New Caledonia”. Eur. J. Mineral. vol. 21, 2009, pp. 467–483.
 R. L. Thorne, R. Herrington, S. Roberts, “Composition and origin of the Caldag˘ oxide nickel laterite deposit, W. Turkey”. Miner. Deposita, vol. 44, 2009, pp. 581–595.
 R. L. Thorne, R. Herrington, S. Roberts, “Climate change and the formation of nickel laterite deposits”. Geology, vol. 40, 2012, pp. 331–334.
 J. P. Golightly, “Progress in understanding the evolution of nickel laterites”. (Eds.), The Challenge of Finding new Mineral Resources—Global Metallogeny, Innovative Exploration, and New Discoveries, Society of Economic Geologists Special Publication, vol. 15. 2010, pp. 451–485.
 J. Roque-Rosell, J. F. W. Mosselmans, J. A. Proenza, M. Labrador, S. Gali, K. D. Atkinson, P.D. Quinn, “Sorption of Ni by ‘‘lithiophorite–asbolane’’ intermediates in Moa Bay lateritic deposits, eastern Cuba”. Chem. Geol. vol. 275, 2010, pp. 9–18.
 W. Fu, J. Yang, M. Yang, B. Pang, X. Liu, H. Niu, X. Huang, “Mineralogical and geochemical characteristics of a serpentinite-derived laterite profile from East Sulawesi, Indonesia: Implications for the lateritization process and Ni supergene enrichment in the tropical rainforest”. Journal of Asian Earth Sciences, vol. 93, 2014, pp. 74–88.
 V. I. Berger, D. A. Singer, J. D. Bliss, B. C. Moring, “Ni–Co laterite deposits of the world—database and grade and tonnage models”. U.S. Department of the Interior & U.S. Geological Survey, Open-File Report 2011-1058, 2011, pp. 1–26.
 M. Alavi, “Tectonostratigraphic evolution of Zagros sides of Iran”. Geology, vol. 8, 1980, pp. 144–149.
 H. A. Babaie, A. Babaie, A. M. Ghazi, M. Arvin, “Geochemical, 40Ar/39Ar age, and isotopic data for crustal rocks of the Neyriz ophiolite, Iran”. Canadian Journal of Earth Sciences, vol. 43 (1), 2006, pp. 57–70.
 M. A. Rajabzadeh, “Mineralisation en chromite et elements du groupe du platine dans les ophiolites d’Assemion et de Neyriz, centrure du Zagros, Iran”. Ph.D. These: Institue National Polytechnique de Lorraine, France, 1998, p. 358.
 R. Stoneley, “The geology of the kuh-e Dalneshin area of southern Iran and its bearing on the evolution of southern Tethys”. Geological Society of London 138, 1981, pp. 509–526.
 M. A. Rajabzadeh, T. Nazari Dehkordi, S. Caran, “Mineralogy, geochemistry and geotectonic significance of mantle peridotites with high-Cr chromitites in the Neyriz ophiolite from the outer Zagros ophiolite belts, Iran”. Journal of African Earth Sciences, vol. 78, 2013, pp. 1–15.
 B. Oveisi, “Geological map of Surian. – Geol. Survey of Iran”. 2001, 109 p. (in Persian)
 G. Estefan, R. Sommer, J. Ryan, “Methods of Soil, Plant, and Water Analysis: A manual for the West Asia and North Africa region”. International Center for Agricultural Research in the Dry Areas (ICARDA), Lebanon,Third Edition, 2013.
 L. A, Haskin, T. R. Wildeman, M. A. Haskin “An accurate procedure for the determination of the rare earths by neutron activation”. J Radioanal Chem. vol. 1, 1968, pp. 337–348.
 J. P. Golightly, Nickeliferous laterite deposits. In: Economic Geology, 75th Anniversary Volume, 1981, pp. 710–735.
 S. A. Gleeson, C.R.M. Butt, M. Elias, “Nickle laterites: a review”. Newslett. Soc. Econ. Geol. vol. 4, 2003, pp. 12–18.
 M. Elias, M. J. Donaldson, N. Giorgetta, “Geology, mineralogy, and chemistry of lateritic nickel–cobalt deposits near Kalgoorlie, Western Australia”. Econ. Geol. vol. 76, 1981, pp. 1775–1783.
 D. Cluzel, B. Vigier, “Syntectonic mobility of supergene nickel ores of New Caledonia (Southwest Pacific) evidence from Garnierite Veins and Faulted Regolith”. Resource Geol. vol. 58, 2008, pp. 161–170.
 M. L. Carvalho-E-Silva, A. Y. Ramos, H. C. N. Tolentino, J. Enzweiler, S. M. Netto, M. C. M. Alves, “Incorporation of Ni into natural goethite: an investigation by X-ray absorption spectroscopy”. Am. Mineral. vol. 88, 2003, pp. 876–882.
 Z. Q. Shi, E. Peltier, D. L. Sparks, “Kinetics of Ni sorption in soils: roles of soil organic matter and Ni precipitation”. Environ. Sci. Technol. Vol. 46, 2012, pp. 2212–2219.
 M. K. Scoot, “Regolith geochemistry of elements, (In: Regolith Science: Scott, M. K. and Pain, C. F, editors), Springer-CSIRO Publishing”. 2008.
 Sufriadin, “Mineralogy, geochemistry, and leaching behavior of the Soroako nickeliferous laterite deposits, Sulawesi, Indonesia”. Summery, Graduate Program of Geological Engineering Faculty of Engineering, Gadjah Mada University Yogyakarta, 2013.