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

Document Type : Research Article

Authors

• Mohammad Ali Rajabzadeh
• Kiamars Hosseini
• Zohreh Moosavi Nasab

Shiraz

10.22067/econg.v6i2.20956

Abstract

Introduction
Iron-apatite ore deposits well known as Kiruna iron type formed in association with calc-alkaline volcanism from Proterozoic to Tertiary (Hitzman et al., 1992). Liquid immiscibility in an igneous system was proposed to explain the formation of the iron oxides accompanying apatite in mineralized zones (Förster and Jafarzadeh, 1994; Daliran, 1999). The mode of ore formation however, is a matter in debate. Bafq region in Central Iran is one of the greatest iron mining regions in Iran with 750 million tons of reservoir. The majority of the iron deposits contains apatite as minor mineral and underwent metamorphism-alteration in varying degrees. The mode of formation and geological setting of Esfordi iron-apatite deposit in this region with an average of 13.9 wt% apatite are discussed using geochemical and mineralogical data along with field description.

Materials and methods
Fifty-three samples of mineralized zones and host rocks collected from 7 cross sections were studied by conventional microscopic methods. Seven representative samples were determined by XRD at Department of Physics, Shiraz University. Fifteen and six samples were also analyzed for major and trace elements using XRF at Binaloud Co. Iran, and ICP-MS at Labwest Minerals Analysis, Australia, respectively. Microprobe analyses were carried out on apatite in Geo Forschungs Zentrum Telegrafenberg at Potsdam University, Germany.


Results
Field observation shows that igneous host rocks in Esfordi were intensively altered by hydrothermal fluids. The ores are surrounded by wide altered halos. Petrographic investigation indicated that the most important alterations are of potassic, carbonatitic and silicification types. Magnetite and apatite occur as major minerals, accompanied by minor hematite and goethite in the mineralized zones. Rare Earth Element (REE) minerals are present as minor phases in the ores. Three apatite mineralization types (vein, massive, and disseminated) were recognized. Petrographic data represent three apatite generations: stage 1 which is recognized in the massive and disseminated ore types, stage 2 occurred in brecciated zones and stage 3 which is formed by dissolution and redeposition of the 1 and 2 apatite types in vein-shaped bodies. The correlations among major elements and SiO2 correspond to magmatic differentiation. Cerium is the most abundant REE in the studied samples. Similar REE distribution patterns were observed in the apatite, magnetite and host rhyolite. Electron Probe Micro Analysis (EPMA) shows that the apatites are of fluoroapatite type, enriched in LREE. Low content of Sr was detected in apatites of Esfordi. Low Cd and Na concentrations but high U and Th values were also detected in the studied ore samples.


Discussion
Esfordi iron-apatite deposit is located NE of Bafq, Yazd Province, and in the Central Iran structural zone hosted by mainly Infracambrian rhyolites. Field evidence such as flow structure of ore and dendritic texture of some minerals, e.g., actinolite reveal the magmatic origin of iron-apatite deposit. The trends of major element concentrations in ores from different rocks are consistent with magmatic origin of the ores. The absence of sulfides shows an oxidized condition of magma at the time of ore formation. Low Sr in the apatite however, rejects any carbonatitic magma at Esfordi (Belousova et al., 2002). Similar REE distribution patterns in the apatite, magnetite and host rhyolite indicates the same origin for them. Cerium concentration in the ores from Esfordi is also consistent with magmatic ore types and negatively sloped REE distribution pattern and negative Eu anomaly resemble to the Kiruna type iron-apatite deposits (Hsieh et al., 2008). Low Cd and variable Th/U in the apatite along with low Na are contradicting with sedimentary environment (Jami, 2005; Alves, 2008). The Esfordi deposit probably formed in an extensional arc-related setting associated with syn-collision granitoids.

Acknowledgements
The authors appreciate Shiraz University Research Council that supported this work. The Director General of the Esfordi Mine Company is acknowledged for his assistance in the fieldwork.


References
Hitzman, M.W., Oreskes ,N. and Einaudi, M.T., 1992. Geological characteristics and tectonic setting of Proterozoic Iron oxide (Cu-U-Au-LREE) deposits. Precambrian Research, 58(1-4): 241-287.
Förster, H. and Jafarzadeh, A., 1994. The Bafq mining district in Central Iran a highlymineralized Infracambrian volcanic field. Economic Geology, 89(8):1697-1721.
Daliran, F., 1999. REE geochemistry of Kiruna –type iron ores. In: C. J. Stanley (Editor), Mineral Deposite, processes to processing. Balkema, Rotterdam, pp. 631-634.
Belousova, E.A., Griffin, W.L., O Reilly, S.Y. and Fisher, N.I., 2002. Apatites as indicator mineral for mineral exploration: trace-element compositions and their relationship to host rock type. Journal of Geochemical Exploration, 76(1): 45-69.
Hsieh, P.S., Chen, C.H., Yang, H.J. and Lee, C.Y. 2008. Petrogenesis of the Nanling Mountains granites from South China: Constraints from systematic apatite geochemistry and whole-rock geochemical and Sr–Nd isotope compositions. Journal of Asian Earth Sciences, 33(5-6): 428–451.
Jami, M., 2005. Geology, Geochemistry and Evolution of theEsfordi Phosphate – Iron Deposit, Bafq Area, Central Iran. Ph.D. thesis, The University of New South Wales, Australia, 220 pp.
Alves, P.R., 2008. The carbonatite-hosted deposit of Jacupiranga, SE Brazil: styles of mineralization, ore characterization, and association with mineral processing. M.Sc. thesis, Missori University of Sciences and Technology, USA, 140 pp.

Keywords

• Mineralogy
• Geochemistry
• apatite
• phosphate
• Esfordi

20.1001.1.20087306.1393.6.2.9.6

---

References

Alves, P.R., 2008. The carbonatite-hosted deposit of Jacupiranga, SE Brazil: styles of mineralization, ore characterization, and association with mineral processing. M.Sc. thesis, Missori University of Sciences and Technology, USA, 140 pp.

Andreoli, M.A.G., Smith, C.B., Watkeys, M., Moore, J.M., Ashwal, L.D. and Hart, R.J., 1994. The geology of the Steenkampskraal monazite deposit, South Africa: Implications for REE-Th-Cu mineralization in charnockite-granuliteterranes. Economic Geology, 89(5): 994–1016.

Baier, E., 1940. Das iransche binnenland ostlich beckens Von Nain-yazd Neues jahrbuch fur mineralogy, Geology und palaontologie,Beilage- band. Neues Jahrbuch für Mineralogie Abhandlungen, 83(1): 46-86.

Belousova, E.A., Griffin, W.L., O Reilly, S.Y. and Fisher, N.I., 2002. Apatites as indicator mineral for mineral exploration: trace-element compositions and their relationship to host rock type. Journal of Geochemical Exploration, 76(1): 45-69.

Bohen, E., 1929. Uberblick uber die erzlagerstatter per siens unden derzeitigen stand Von gewinnung und Verhuttung. Erzmetall, 26(4): 57-61.

Bonyadi, Z., 1999. Geochemistry and genesis of Narigan manganese deposit, Bafgh-Yazd. M.Sc. thesis, Siraz University, Shiraz, Iran, 157 pp. (in Persian)

Borumandi, H., 1973. Petrographische and Lagerstatten Kundliche unter suter suchungen der Esfordi – formation zwischen Mishdowan and Kushk bie bafgh central iran. Ph.D. Dissertation, Aachen University, Aachen, Germany, 174 pp.

Boynton, W.V., 1985. Cosmochemistry of the rare earth elements: Meteorite studies. In: P. Henderson) Editor), Rare Earth Element Geochemistry. Elsevier, Amsterdam, pp. 115-1522.

Chu, M.F., Wang, K.L., Griffin, W.L., Chung ,S.L., O’Reilly, S.Y., Pearson, N.J. and Iizuka Y. 2009. Apatite composition: Tracing petrogenetic processes inTranshimalayan granitoids. Journal of Petrology, 50(10): 1829-1855.

Coppin, F., Berger, G., Castet, S. and Loubet ,M., 2002. Sorption of lanthanides on smectite and kaolinite. Chemical Geology, 182(1): 57-68.

Cox, K.J., Bell, J.D. and Pankhurst, R.J., 1979. The interpretation of igneous rocks. George Allen and Unwin, London, 464 pp.

Daliran, F., 1999. REE geochemistry of Kiruna –type iron ores. In: C. J. Stanley (Editor), Mineral Deposite, processes to processing. Balkema, Rotterdam, pp. 631-634.

Daliran, F., 2002. Kiruna-type iron oxide-apatite ores and apatitites of the Bafq district, Iran, with an emphasis on the REE geochemistry of their apatites. In: T.M. Porter (Editor), Hydrothermal iron oxide copper - gold and related deposits, PGC Publishing, Linden Park, South Australia, pp. 303-320.

Darvishzadeh, A., 1983. Investigation of Bafg-Esfordi phosphate. Journal of Sciences Tehran University, 13(1-2): 2-24 (in Persian).

Edfelt, A., 2007. The Tjårrojåkka Apatite-Iron and Cu (-Au) Deposits, Northern Sweden. Ph.D. thesis, Division of Ore Geology and Applied Geophysics, Luleå University of Technology, Sweden, 230 pp.

Ezatian, E., 2002. Atlas of igneous rocks, classification and nomenclature. Geological Survey of Iran.

Farkhondi Sorkhabi, K., 1998. Investigation of rare earth elements (REE) and Nb distributions in iron-apatite deposits of Bafgh area. M.Sc. thesis, Shahid Beheshti University, Tehran, Iran, 234 pp. (in Persian)

Förster, H. and Borumandi, H., 1976. Petrographic observation on a magnetite deposit at Mishdovan, Central Iran. Economic Geology, 74(1): 1485-1489.

Förster, H. and Jafarzadeh, A., 1994. The Bafq mining district in Central Iran a highlymineralized Infracambrian volcanic field. Economic Geology, 89(8):1697-1721.

Förster, H. and Knittel, U., 1979. Petrographic observation on a magnetite deposit at mishdovan, central Iran. Economic Geology, 74(6): 1485-1489.

Frietsch, R. and Perdahl, J.A., 1995. Rare earth elements in apatite and magnetite in kiruna –type iron ores and some other iron ore type. Ore Geology Reviews, 9(6): 489-510.

Fuge, R., 1977, On the behavior of fluorine and chlorine during magmatic differentiation. Contributions to Mineralogy and Petrology, 61(3): 245-249.

Haghipour, A., 1974. Etude geologique la region de Biabanak - Bafq (Centeral Iran); Petrologie et tectonique du socle percamberien et sacouverture. Ph.D. These, Universite Scientifique et Medicale de Grenobal, France , 403 pp.

Hall, A., 1998. Igneous Petrology. Longman, UK, 550 pp.

Helvaci, C., 1984. Apatite-Rich Iron Deposits of the Avnik (Bingol) Region, Southeastern Turkey. Economic Geoloy, 79(2): 354-371.

Hitzman, M.W., Oreskes ,N. and Einaudi, M.T., 1992. Geological characteristics and tectonic setting of Proterozoic Iron oxide (Cu-U-Au-LREE) deposits. Precambrian Research, 58(1-4): 241-287.

Hooshmandzadeh , A., Nabavi, M.J. and Hamdi, B., 1988. Precambrian-Lower Cambrian rocks in Iran. 1st Conference of Investigation on Resources and Mineral Potential in Yazd Province, Yazd, Iran. (in Persian)

Houkriede, R., Kursten, M. and Vanzlaff, H., 1962. Zur geologeie des gebeietes zwischen kerman und Saghand (Iran). Beihefte zum Geologischen Jahrbunch, 51(2): 1-179.

Hsieh, P.S., Chen, C.H., Yang, H.J. and Lee, C.Y. 2008. Petrogenesis of the Nanling Mountains granites from South China: Constraints from systematic apatite geochemistry and whole-rock geochemical and Sr–Nd isotope compositions. Journal of Asian Earth Sciences, 33(5-6): 428–451.

Irvine, T.N. and Baragar, W.R.A., 1971. A guide to the chemical classification of the common volcanic rocks. Canadian Journal of Earth Sciences, 8(5): 523-548.

Iwao, S. and Zahedi, M., 1966. Geology and iron ore deposit of Chadormalu mine Bafgh area Central Iran. Geological Survey of Iran, Tehran, Report 10, 8 pp.

Jami, M., 2005. Geology, Geochemistry and Evolution of theEsfordi Phosphate – Iron Deposit, Bafq Area, Central Iran. Ph.D. thesis, The University of New South Wales, Australia, 220 pp.

Jensen, L.S., 1976. A new cation plot for classifying subalkalic volcanic rocks. Division of Mines, Ontario, Report 66, 22 pp.

Jinjie,Y.U., Qi, Z., Jingwen, M., Shenghao, Y. 2007, Geochemistry of Apatite from the Apatite-rich Iron Deposits in the Ningwu Region, East Central China. Acta Geologica Sinica (English Edition), 81(4): 637–648.

Jones, A.P., Wall, F. and Williams, C.T. 1996. Rare Earth Minerals: Chemistry, Origin and Ore Deposits. Mineralogical Society of Great Britain and Ireland: The Mineralogical Society Series. 7. Chapman & Hall, UK, 372 pp.

Koeppenkastrop, D. and De Carlo, E.H., 1993. Uptake of rare earth elements from solution by metal oxides. Environmental and Science Technology, 27(9): 1796-1802.

Lottermoser, B.G., 1992. Rare earth elements and hydrothermal ore formation processes. Ore Geology Review, 7(1): 25-41.

Lovering, T.G. and Heyl, A.V., 1974. Jasperoid as a guide to mineralization in the Taylor mining district and vicinity near Ely, Nevada. Economic Geology, 69(1): 46-58.

Mathez, E.A. and Webster, J.D., 2005. Partitioning behavior of chlorine and fluorine in the system apatite- silicate melt- fluid. Geochimica et Cosmochimica Acta, 69(5): 1275-1286.

Moor, F. and Modabberi, S., 2003. Origin of choghart iron oxide deposite Bafq minig districte, centeral Iran: new isotopic and geochemical evidences. Journal of Sciences Islamic Republic of Iran, 14(3): 259-269.

Moosavinasab, Z., 1997. Geochemistry and genesis of Choghart iron deposit, Bafgh-Yazd. M.Sc. thesis, Shiraz University, Tehran, Iran, 201 pp. (in Persian)

Nystrom, J.O. and Henriquez, R., 1994. Magmatic features of iron ores of the kiruna type in chile and widen: ore textures and magnetite geochemistry. Economic Geology, 89(4): 820-839.

Paknejad, H., 1991. Complementary exploration of Esfordi deposit. Geological Survey of Iran, Tehran, Report 11, 89 pp. (in Persian)

Parak, T., 1975. Kiruna iron ores are not ‘intrusive-magmatic ores of the Kiruna type. Economic Geology, 70(7): 1242–1258.

Pearce, J.A., Harris, N.B.W. and Tindle, A.G., 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4): 956-983.

Pichler, H. and Reigraf, C.S. (Translated by Mehrabi, F.), 1995. Gesteinsbildende minerale im duennschliff. Shiraz University Press, Shiraz, 230 pp. (in Persian)

Rollinson, H.R., 1993. Using geochemical data: evaluation, presentation, interpretation. Routledge, USA, 384 pp.

Rønsbo, J.G., 1989. Coupled substitution involving REEs and Na and Si in apatites in alkaline rocks from the Ilimaussaq intrusion, South Greenland, and the petrological implications. American Mineralogist, 74: 896–901.

Ruzicka, V., 1990. Vein uranium deposits. Ore Geology Review, 8: 247 - 276.

Samani, B., 1998. Precambrian metallogenic in Central Iran. Scientific Bulletin of the Atomic Energy Organization of Iran, 17(1): 1-16.

Stahl, A.F., 1911. Persian. In: A.F. Stahl (Editor), Handbuch der regionalen geologie. Heidelberg (Winter), Germany, pp. 275-279.

Sverjensky, D.A., 1984. Europium redox equilibria in aqueous solution. Earth and Planetary Science Letters, 67(1): 70-78.

Torab, F., 2008. Geochemistry and metallogeny of magnetite-apatite deposits of the Bafq Mining District, Central Iran. Ph.D. Thesis, Faculty of Energy and Economic Sciences, Clausthal University of Technology, Germany, 144 pp.

Torab, F.M., 2010. Geochemistry and radioisotope investigations to determine apatite setting in iron-apatite deposits in Bafgh mining district. Irananin Journal of Crystallographyand Mineralogy, (3): 409-418. (in Persian)

White, R.A., 2000. Behavior of the rare earth elements in ochreous mine drainage: a elaborately and field study. Ph.D. thesis, University of Wales, UK, 210 pp.

Winchester, J.A. and Floyd, P.A., 1977. Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chemical Geology, 20:325-343.

Witford, D.J., Korsch, M.J., Porritt, P.M. and Craven, S.J., 1980. Rare earth elemnt mobility around the volcanogenic polymetallic massive sulfide deposit at Que river, Tasmania Australia. Chemical Geology, 68(1): 105-119.

Wood, D.A., 1980. The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province. Earth and Planetary Science Letters, 50(1): 11-30.

Zui, C., 1994. Evolution of apatite mineralization Potential in Central Iran. Remote Sensing Project. Iranian Ministry of Industry and Mine, Tehran, Report 2, 20 pp.