Trace Elements Geochemistry in the Zagros Phosphorite Horizon: New Approach on Deposition and Genesis

Document Type : Research Article

Authors

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

Abstract

Introduction
Phosphorites are marine sediments of biogenic origin containing 15–20 wt% P2O5 and between 50 and 120 ppm U (Boggs, 2009; Tzifas et al., 2014; Zarasvandi et al., 2019). The study of phosphorites, especially trace elements geochemistry, confirms the importance of deposition conditions and diagenesis on the elemental composition of phosphatic minerals. Even more importantly, marine phosphorites are considered to have an economic potential for elements such as REE, Sc, U and Th (Altschuler, 1980). Some trace elements, including Sr, Ba, Se, Mo, Ag, Pb, Zn, V, Cr, Ni, Cu, Cd, and U are commonly found in phosphorites and sediments rich in phosphorus related to the crystal structure of apatite and carrier organic ligands (Tzifas et al., 2014; Zarasvandi et al., 2019). In general, more than seven horizons with an extent of ∼400 to 100km have been delineated in the Zagros Mountains. The Zagros phosphorite horizon of Eocene-Oligocene age hosted by the Pabdeh Formation is located in the Zagros fold belt with NW-SE trend (Halalat and Bolourchi, 1994; Zarasvandi et al., 2019). The aim of this study is to investigate the geochemistry of trace elements in order to obtain the deposition and genesis conditions of these elements in the Zagros phosphorite horizon.
 
Materials and methods
A total of 29 samples were taken from phosphorite, hydrocarbon-bearing shale, phosphorite and limestone and oxide zone of the studied phosphorites of Zagros. Hence, based on stratigraphy, different samples from Zagros phosphorite horizons were collected from the phosphorites of Kuh-e-Sefid (n=9), Kuh-Rish (n=12) and Sheykh-Habil (n=8). Mineralogical and geochemical studies were carried out using ICP-MS analyses. 20 polished-thin sections were prepared. Mineralogy and petrography of the samples was determined and examined using polarizing-reflected light optical microscopy at the Shahid Chamran University of Ahvaz in Iran. Geochemical studies on mineralized and host rocks of Zagros phosphorite horizon were performed by the ICP-MS technique (Thermo Scientific- X Series II; DL= 0.001 ppb) at the Department of Earth Sciences, Pondicherry University in India.
 
Results
According to the petrographic studies, phosphorite components and non-phosphorite components mainly consist of pellets, Ooids, intraclasts, fish skeletal fragments, micro-fossils, glauconite, calcite, pyrite, iron-oxide and quartz. Several elements that substitute Ca including rare earth elements and trace elements are suitable for contribution in the carbonate-rich fluorapatite (francolite) crystalline structure. Thus, some oxo-anions such as VO4, As2O4, SO2, SO4 and CO3 can be substituted into PO4 structure in apatite group lattices (Tzifas et al., 2014; Zarasvandi et al., 2019). Consistently, the Zagros phosphorite horizon exhibits different concentrations of elements such as Sr, REE, Zn, V, Mo, Cr, Cd, Se, As and U. Trace element distribution patterns in the studied phosphorites are similar to phosphorite in Iran and worldwide, especially in terms of concentration of U, Se, and Cd that can be related to apatite group minerals crystal lattice (Tzifas et al., 2014; Zarasvandi et al., 2019). Due the low entrance rate of detrital components from continental to the basin, the most probable source for trace elements is hydrocarbon-bearing shale in the stratigraphic column as a result of activities of microorganisms.
 
Discussion
Field observation and microscopic studies showed that the phosphorite components occur as authigenic apatite with sparite cement, abundant pellets, ooids of symmetrical to elongated shape due to pressures caused by diagenesis, oval shape intraclasts, fish skeletal fragments and abundant microfossils. In additions to phosphorite and biogenic components, non-phosphorite minerals such as calcite, glauconite, pyrite, iron oxide, and microcrystalline quartz are present.
There are many indications of change in conditions. They include bituminous shale in stratigraphic sequence, presence of abundant framboidal pyrites, PAAS-normalized patterns of REEs, negative Ce anomaly of all samples and positive Eu anomalies of all samples except bituminous shale sample of Kuh-e Rish phosphorite, the Ni/Co ratio and also the diagram of V/(V+Ni) vs. Ni/Co. These indicate changes in conditions from oxides during phosphate deposition into dysoxic to anoxic due to degradation and decomposition of organic compounds by microorganisms and the entry of trace elements such as uranium into the crystalline structure of apatite in the Zagros Basin.
The significant economic potential of organometallic elements especially U and REE is observed in the Zagros phosphorite horizon due to favorable conditions of dysoxic to anoxic as a result of decomposition of organic compounds and then the entry of the elements into the apatite crystal structure.
 
References
Altschuler, Z.‌S., 1980. The Geochemistry of Trace Elements in Marine Phosphorites Part I. Characteristic Abundances and Enrichment. In: Y.K. Bentor (Editor), Marine Phosphorites-Geochemistry, Occurrence, Genesis. SEPM Society for Sedimentary Geology, Reston, pp. 19–30. https://doi.org/10.2110/pec.80.29.0019
Boggs, S., 2009. Petrology of Sedimentary Rocks. Cambridge University Press, England, 600 pp. Retrieved October 3, 2020 from https://www.researchgate.net/publication/281604561
Halalat, H. and Bolourchi, M., 1994. Geology of Iran: Phosphate. Geological Survey of Iran, Tehran, 362 pp. (in Persian with English abstract)
Tzifas, I.Tr., Goldelitsas, A., Magganas, A., Anderoulakaki, E., Eleftheriond, G., Mertzimckis, T.J. and Perraki, M., 2014. Uranium-bearing phosphatized limestone of new Greece. Journal of Geochemical Exploration. 143: 62–73. https://doi.org/10.1016/j.gexplo.2014.03.009
Zarasvandi, A., Fereydouni, Z., Pourkaseb, H., Sadeghi, M., Mokhtari, B. and Alizadeh, B., 2019. Geochemistry of trace elements and their relations with organic matter in Kuh-e-Sefid phosphorite mineralization, Zagros Mountain, Iran. Ore Geology Reviews, 104: 72–87. https://doi.org/10.1016/j.oregeorev.2018.10.013
 

Keywords


Abed, A.M., 2011. Review of Uranium in the Jordanian Phosphorites: Distribution, Genesis and Industry. Journal of Earth and Environmental Sciences, 4(2): 35–45.  Retrieved October 3, 2020 from https://www.researchgate.net/publication/288959316
Abed, A.M., 2013. The eastern Mediterranean phosphorite giants: an interplay between tectonics and upwelling. GeoArabia, 18(2): 67–94. Retrieved October 3, 2020 from https://www.researchgate.net/publication/285695505
Abed, A.M., Jaber, O., Alkuisi, M. and Sadaqah, R., 2016. Rare earth elements and uranium geochemistry in the Al-Kora phosphorite province, Late Cretaceous, northwestern Jordan. Arabian Journal of Geosciences, 9(3): 187–206. https://doi.org/10.1007/s12517-015-2135-6
Alavi, M., 2007. Structure of the Zagros Fold-Thrust Belt in Iran. American Journal of Sciences, 307(9):1064–1095. https://doi.org/10.2475/09.2007.02
Al-Bassam, K.S., 1990. The Akashat phosphate deposits, Iraq. In: A.J. Notholt, R.P. Sheldon and D.F. Davidson (Editors), Phosphate Deposits of the World, Phosphate Rock Resources. Cambridge University Press, United Kingdom, pp. 316–322.  Retrieved October 3, 2020  from https://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=6729694
Altschuler, Z.‌S., 1980. The Geochemistry of Trace Elements in Marine Phosphorites Part I. Characteristic Abundances and Enrichment. In: Y.K. Bentor (Editor), Marine Phosphorites-Geochemistry, Occurrence, Genesis. SEPM Society for Sedimentary Geology, Reston, pp. 19–30. https://doi.org/10.2110/pec.80.29.0019
Arning, E.T., Luckge, A., Breuer, C., Gussone, N., Birgel, D. and peckmann, J., 2009. Genesis of Phosphorite Crusts off Peru. Marine Geology, 262(1–4): 68–81. https://doi.org/10.1016/j.margeo.2009.03.006
Avini, M., 1988. Preliminary report of economic technical Studies of Kuh-Rish phosphate deposit (North Behbahan). Ministry of Industry, Mines and Trade, Tehran, 27 pp. (in Persian with English abstract)
Awadalla, G.S., 2010. Geochemistry and microprobe investigations of Abu Tartur REE-bearing phosphorite, Western Desert, Egypt. Journal of African Earth Sciences, 57(5): 431–443. https://doi.org/10.1016/j.jafrearsci.2009.11.009
Baioumy, H., 2011. Rare earth elements and sulfur and strontium isotopes of upper Cretaceous phosphorites in Egypt. Cretaceous Research, 32(3): 368–377. https://doi.org/10.1016/j.cretres.2011.01.008
Baturin, G.N. and Kochenov, A.V., 2001. Uranium in phosphorites. Lithology and Mineral Resources, 36(4): 303–321. Retrieved October 3, 2020 from https://link.springer.com/article/10.1023/A:1010406103447
Bech, J., Suarez, M., Reverter, F., Tume, P., Sánchez, P., Roca, N. and Lansac, A., 2010. Selenium and other trace element in phosphorites: A comparison between those of the Bayovar-Sechura and other provenances. Journal of Geochemical Exploration, 107(2): 146–160. https://doi.org/10.1016/j.gexplo.2010.04.002
Bishady, A.M., Farag, N.M., Mira, H.I., Elsawey, E.S.H. and Negm, S.H., 2019. A Contribution to the geochemistry of El-sibaiya phosphorite, Nile Valley, Egypt. Nuclear Sciences Scientific Journal, 8(1): 39–58. https://doi.org/0.21608/nssj.2019.29945
Boggs, S., 2009. Petrology of Sedimentary Rocks. Cambridge University Press, England, 600 pp. Retrieved October 3, 2020 from https://www.researchgate.net/publication/281604561
Bonnot-Courtois, C. and Fleoteaux, R., 1989. Distribution of Rare-Earth and some trace elements in Tertiary phosphorites from the Senegal Basin and their weathering products. Chemical Geology, 75(4): 311–328. https://doi.org/10.1016/0009-2541(89)90004-1
Brew, G., Barazangi, M., Al-Maleh, A.K. and Sawaf, T., 2001. Tectonics and geologic evolution of Syria. Geoarabia, 6(4): 573–616. Retrieved October 3, 2020 from https://pubs.geoscienceworld.org/geoarabia/article/6/4/573/566764/
Chen, D., Qing, H., Yan, X. and Li, H., 2006. Hydrothermal venting and basin evolution (Devonian, South China): constraints from rare earth element geochemistry of chert. Sedimentary Geology, 183(3–4): 203–216. https://doi.org/10.1016/j.sedgeo.2005.09.020
Cheshmehsari, M., 2012. The mineralogical and geochemical features of Dalir phosphate index (SW of Chalous – Mazandaran province). M.Sc. Thesis, Urmia University, Urmia, Iran, 91 pp. (in Persian with English abstract)
Damiri, K., 2011. Geology, Geochemistry and Genesis of the Phosphate Occurrences in the Pabdeh Formation, southwestern Iran. M.Sc. Thesis, Shahid Chamran University, Ahvaz, Iran, 146 pp. (in Persian with English abstract)
Emsbo, P., Patrick, I., McLaughlin, P.I., Breit, G.N., Du Bray, E.A. and Koenig, A.E., 2015. Rare earth elements in sedimentary phosphate deposits: solution to the global REE crisis? Gondwana Research. 27(2): 776–785.  https://doi.org/10.1016/j.gr.2014.10.008
Fazio, A.M., Scasso, R.A., Castro, L.N. and Carey, S., 2007. Geochemistry of rare earth elements in early- diagenetic Miocene phosphatic concretions of Patagonia, Argentina: Phosphogenetic implications. Deep Sea Research Part II: Topical Studies in Oceanography, 54(11–13): 1414–1432. https://doi.org/10.1016/j.dsr2.2007.04.013
Fereydouni, Z., 2016. Investigating distribution and behavior of Rare Earth Elements and Uranium in the Kuh-e-sefid phosphate ore deposit, Ramhormoz, Khuzestan. M.Sc. Thesis, Shahid Chamran University, Ahvaz, Iran, 222 pp. (in Persian with English abstract)
Gabar, A.E., Arabi, M.E. and Khalifa, I.H., 2002. Application of multivariate statistical analyses in the interpretation of geochemical behaviour of uranium in phosphatic rocks in the Red Sea, Nile Valley and Western Desert, Egypt. Journal of Environmental Radioactivity, 61(2): 169–190. https://doi.org/10.1016/S0265-931X(01)00124-2
Glenn, C.R. and ArThur, M.A., 1988. Petrology and major element geochemistry of Peru margin phosphorites and associated diagenetic minerals: Authigenesis in modern organic-rich sediments. Marine Geology, 80, 231–267. https://doi.org/10.1016/0025-3227(88)90092-8
Halalat, H. and Bolourchi, M., 1994. Geology of Iran: Phosphate. Geological Survey of Iran, Tehran, 362 pp. (in Persian with English abstract)
Hiatt, E.E., Pufahl, P.K. and Edwards, C.T., 2015. Sedimentary phosphate and associated fossil bacteria in a Paleoproterozoic tidal flat in the 1.85 Ga Michigamme Formation, Michigan, USA. Sedimentary Geology, 319: 24–39. https://doi.org/10.1016/j.sedgeo.2015.01.006
Huang, J.H., Huang, F., Evans, L. and Glasauer, S., 2015. Vanadium: Global (bio) geochemistry. Chemical Geology, 417: 68–89. https://doi.org/10.1016/j.chemgeo.2015.09.019
Huerta-Diaz, M.A. and Morse, J.W., 1992. Pyritization of trace metals in anoxic marine sediments. Geochimica et Cosmochimica Acta, 56(7): 2681–2702. https://doi.org/10.1016/0016-7037(92)90353-K
Ilyin, A.V., 1998. Rare-earth geochemistry of ‘old’ phosphorites and probability of syngenetic precipitation and accumulation of phosphate. Chemical Geology, 144(3–4): 243–256. https://doi.org/10.1016/S0009-2541(97)00134-4
Imamoglu, S.M., Nathan, Y., Hakan, C., Soudry, D. and Glenn, C., 2009. Geochemical, mineralogical and isotopic signatures of the Semikan, West Kasrık “Turkish” phosphorites from the Derik–Mazıdagı–Mardin area, SE Anatolia. International Journal of Earth Sciences, 98(7): 1679–1690. https://doi.org/10.1007/s00531-008-0332-1
Jarvis, I., 1980. Geochemistry of phosphatic chalks and hardgrounds from the Santonian to early Campanian (Cretaceous) of northern France. Journal of the Geological Society, 137(6): 705–721. https://doi.org/10.1144/gsjgs.137.6.0705
Jarvis, I., 1992. Sedimentology, geochemistry and origin of phosphate chalks. the upper cretaceous deposits of NW Europe. Sedimentology 39(1): 55–97. https://doi.org/10.1111/j.1365-3091.1992.tb01023.x
Jiang, S.Y., Zhao, H.X., Chen, Y.Q., Yang, T., Yang, J.H. and Ling, H.F., 2007. Trace and rare earth element geochemistry of phosphate nodules from the lower Cambrian black shale sequence in the Mufu Mountain of Nanjing, Jiangsu province, China. Chemical Geology, 244(3–4): 584–604. https://doi.org/10.1016/j.chemgeo.2007.07.010
Jones, B. and Manning, D.C., 1994. Comparison of geochemical indices used for the interpretation of paleo-redox conditions in Ancient mudstones. Chemical Geology, 111(1–4): 111–129. https://doi.org/10.1016/0009-2541(94)90085-X
Kechiched, R., Laouar, R., Bruguier, O., Kocsis, L., Salmi-Laouar, S., Bosch, D., Ameur-Zaimeche, O., Foufou, A. and Larit, H., 2020. Comprehensive REE+ Y and sensitive redox trace elements of Algerian phosphorites (Tébessa, eastern Algeria): A geochemical study and depositional environments tracking. Journal of Geochemical Exploration, 208: 106–396. https://doi.org/10.1016/j.gexplo.2019.106396
Khan, K.F., Dar, Sh.A. and Khan, S.A., 2012. Rare earth element (REE) geochemistry of phosphorites of the Sonrai area of Paleoproterozoic Bijawar basin, Uttar Pradesh, India. Journal of Rare Earths, 30(5): 507–514. https://doi.org/10.1016/S1002-0721(12)60081-7
Khirekesh, Z., 2016. Mineralogy and Geochemistry of phosphate rock in Firuzkuh region. M.Sc. Thesis, Golestan University, Gorgan, Iran, 78 pp. (in Persian with English abstract)
Kidder, D., Krishnaswamy, R. and Mapes, R.H., 2003. Elemental mobility in phosphatic shales during concretion growth and implication for provenance analysis. Chemical Geology, 198(3–4): 335–353.  https://doi.org/10.1016/S0009-2541(03)00036-6
Matter, W.S.A., 1996. Geology of the early paleogene phosphorite deposits of Northwestern Saudi Arabia. Ph.D. Thesis, King Fahd University of Petroleum and Minerals, Saudi Arabia, 380 pp.
McClellan, G.H., 1980, Mineralogy of carbonate-fluorapatite. Journal of the Geological Society, London. 137(6): 675–681. https://doi.org/10.1144/gsjgs.137.6.0675
Morford, J.L. and Emerson, S., 1999. The geochemistry of redox sensitive trace metals in sediments. Geochimica et Cosmochimica Acta, 63(11–12): 1735–1750.  https://doi.org/10.1016/S0016-7037(99)00126-X
Okubo, J., Muscente, A.D., Luvizotto, G.L., Uhlein, G.J. and Warren, L.V., 2018. Phosphogenesis, aragonite fan formation and seafloor environments following the Marinoan glaciation. Precambrian Research, 311: 24–36. https://doi.org/10.1016/j.precamres.2018.04.002
Pasero, M., Kampf, A.R., Ferraris, C., Pekov, I.V., Rakova, J. and White, T., 2010. Nomenclature of apatite supergroup minerals. European Journal of Mineralogy, 22(2): 163–179. https://doi.org/10.1127/0935-1221/2010/0022-2022
Pourmad, A., Dauphas, N. and Ireland, T.J., 2012. A novel extraction chromatography and MC-ICP-MS technique for rapid analysis of REE, Sc and Y: Revising CI-chondrite and Post-Archean Australian Shale (PAAS) abundances. Chemical Geology, 291: 38–54.  https://doi.org/10.1016/j.chemgeo.2011.08.011
Rajabzadeh, M.A., Hoseini, K. and Moosavinasab, Z., 2014. 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)
Rakovan, J., Reeder, R.J., Elzinga, E.J., Cherniak, D., Tait, C.D. and Morris, D.E., 2002. Characterization of U(VI) in the apatite structure by X-ray absorption spectroscopy. Environmental Science & Technology, 36(14): 3114–3117. Retrieved October 3, 2020 from https://pubs.acs.org/doi/abs/10.1021/es015874f
Reynard, B., Lecuyer, C. and Grandjean, P., 1999. Crystal-chemical controls on Rare earth element concentrations in fossil biogenic apatites an implication for paleoenvironmental reconstructions. Chemical Geology, 155(3–4): 233–241. https://doi.org/10.1016/S0009-2541(98)00169-7
Rimmer, S.M., 2004. Geochemical paleoredox indicators in the Devonian– Mississippian black shales, central Appalachian Basin (USA). Chemical Geology. 206(3–4): 373–391. https://doi.org/10.1016/j.chemgeo.2003.12.029
Robertson, A.H.F. and Dixon J.E., 1984. Introduction: aspects of the geological evolution of the Eastern Mediterranean. In: J.E. Dixon and A.H. Robertson (Editors), The Geological Evolution of the Eastern Mediterranean. Geological Society, London, pp. 1–74. https://doi.org/10.1144/GSL.SP.1984.017.01.02
Sharland, P.R., Casey, D.M., Davies, R.B., Simmons, M.D. and Sutcliffe, O.E., 2004. Arabian plate sequence stratigraphy–revisions to SP2. GeoArabia, 9(1): 199–214. Retrieved October 3, 2020 from https://pubs.geoscienceworld.org/geoarabia/article/9/1/199/566966
Shi, C.H. and Hu, R.Z., 2005. REE geochemistry of Early Cambrian phosphorites from Gezhongwu Formation at Zhijin, Guizhou Province, China. Chinese Journal of Geochemistry, 24(2): 166–172. Retrieved October 3, 2020 from https://link.springer.com/article/10.1007/BF02841161
Silva, E.F.D., Mlayahb, A., Gomesa, C., Noronhac, F., Charefb, A., Sequeiraa, C., Estevesd, V. and Marquesd, A.R.F., 2010. Heavy elements in the phosphorite from Kalaat Khasba mine (North-western Tunisia): Potential implications on the environment and human health. Journal of Hazardous Materials, 182(1–3): 232–245.  https://doi.org/10.1016/j.jhazmat.2010.06.020
Slansky, M., 1979. Geology of Sedimentary Phosphates. North Oxford Academic, United Kingdom, 210 pp. Retrieved October 3, 2020  from https://www.researchgate.net/publication/236431754
Soudry, D., Ehrlich, S., Yoffe, O. and Nathan, Y., 2002. Uranium oxidation state and related variations in geochemistry of phosphorites from the Negev (southern Israel). Chemical Geology, 189(3–4): 213–230. . https://doi.org/10.1016/S0009-2541(02)00144-4
Soudry, D., Glenn, C.R., Nathan, Y., Segal, I. and VonderHaar, D., 2006. Evolution of Tethyan phosphogenesis along the northern edges of the Arabian–African shield during the Cretaceous–Eocene as deduced from temporal variations of Ca and Nd isotopes and rates of P accumulation. Earth-Science Reviews, 78(1–2): 27–57. https://doi.org/10.1016/j.earscirev.2006.03.005
Taylor, S.R. and McLennan, S.M., 1985. Continental Crust: Its Composition and Evolution. Blackwell, Oxford, 311 pp. Retrieved October 3, 2020 from https://www.researchgate.net/publication/313050953
Tzifas, I.Tr., Goldelitsas, A., Magganas, A., Anderoulakaki, E., Eleftheriond, G., Mertzimckis, T.J. and Perraki, M., 2014. Uranium-bearing phosphatized limestone of new Greece. Journal of Geochemical Exploration. 143: 62–73. https://doi.org/10.1016/j.gexplo.2014.03.009
Varol, B., 1989. Sedimentray Petrography and Origin of Phosphate Peloids of the Mazıdağ-Derik Area (Mardin, Southeast Turkey). Maden Tetkik ve Arama Dergisi, 109(109): 65–73. Retrieved October 3, 2020 from https://dergipark.org.tr/en/pub/bulletinofmre/issue/3928/52267
Veeh, H.H., Calvert, S.E. and Price, N.B., 1974. Accumulation of uranium in sediments and phosphorites on the South West African shelf. Marine Chemistry, 2(3): 189–202. https://doi.org/10.1016/0304-4203(74)90014-0
Voyseh, S., 2017. The prospecting report of rare earth elements in the sedimentary phosphate horizons of Iran. Geological Survey and Mineral Exploration of Iran, Tehran, 218 pp. (in Persian with English abstract)
Whitney, D.L. and Evans, B.W., 2010. Abbreviations for names of rock-forming minerals. American Mineralogist, 95(1): 185–187. https://doi.org/10.2138/am.2010.3371
Wright, J., Schrader, H. and Holser, W.T., 1987. Paleoredox variations in ancient oceans recorded by rare earth elements in fossil apatite. Geochimica et Cosmochimica Acta 51(3): 631–644.  https://doi.org/10.1016/0016-7037(87)90075-5
Yang, H., Xiao, J., Xia, Y., Xie, Z., Tan, Q., Xu, J., Guo, H., He, S. and Wu, S., 2019. Origin of the Ediacaran Weng'an and Kaiyang phosphorite deposits in the Nanhua basin, SW China. Journal of Asian Earth Sciences, 182: 103–931. https://doi.org/10.1016/j.jseaes.2019.103931
Ye, Y., Wang, H., Wang, X., Zhai, L., Wu, C. and Zhang, S., 2020. Elemental geochemistry of lower Cambrian phosphate nodules in Guizhou Province, South China: An integrated study by LA-ICP-MS mapping and solution ICP-MS. Palaeogeography, Palaeoclimatology, Palaeoecology, 538: 109–459. https://doi.org/10.1016/j.palaeo.2019.109459
Zarasvandi, A., Fereydouni, Z., Pourkaseb, H., Sadeghi, M., Mokhtari, B. and Alizadeh, B., 2019. Geochemistry of trace elements and their relations with organic matter in Kuh-e-Sefid phosphorite mineralization, Zagros Mountain, Iran. Ore Geology Reviews, 104: 72–87. https://doi.org/10.1016/j.oregeorev.2018.10.013
 
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