Geology, geochemistry, fluid inclusion and genesis of the Arabshah magnetite-apatite mineralization, SE Takab

Document Type : Research Article

Authors

1 Associate Profesor, Department of Geology, Faculty of Sciences, University of Zanjan, Zanjan, Iran

2 M.Sc., Mineralogy Lab., Iran Mineral Processing Research Center (IMPRC), Tehran, Iran

Abstract

The Arabshah Fe mineralization is the only known magnetite-apatite mineralization at the Takab–Takht-e-Soleyman–Angouran subzone in southeast of Takab. The oldest rock units in the mineralization area include sedimentary succession of the Qom Formation that was intruded by the Pliocene Ayoub Ansar volcanic dome. Magnetite- apatite mineralization at the Arabshah occurs as vein-veinlets with E-W stright within the Ayoub Ansar dacitic dome. Brecciated zones containing narrow magnetite vein- veinlets occur at footwall and hanging wall of the main vein. Hydrothermal alterations include sodic-calcic, silicification and argillic. Magnetite is the only ore mineral in this mineralization which is accompanied with apatite, clinopyroxene, albite and quartz as gangue minerals. Mineralization textures in the Arabshah deposit include vein-veinlet, brecciated, disseminated, and replacement. REEs concentration within apatite crystals are more than 1%, and demonstrate LREE enrichment with high LREE/HREE ratio and distinctive negative Eu anomalies which is indicative for Kiruna- type iron ores. The result of fluid inclusion studies indicates the presence of two-phase and poly-phase inclusions include LV, VL, LVH, LVS and LVHS fluid inclusions with homogenization between 230-550 °C. The salinity of halite bearing poly-phase fluid vary between 35-60 wt.% NaCl equiv. Fluid inclusion data indicates that Arabshah magnetite-apatite mineralization originated from magmatic fluids. Evidences like mineral assemblages, hydrothermal alteration, ore structure and textures, geochemical characteristics and fluid inclusion data, indicate that the Arabshah magnetite-apatite mineralization can be classified as Kiruna-type iron ores.
 
 
Introduction
Iron oxide-apatite deposits (IOA) are considered to be Kiruna-type iron ores which have formed between Protrozoic to Tertiary eras in different parts of the world. Apatite occurs as a major constituent of these deposits which is accompanied by magnetite and some actinolite. Higher concentration of REEs is one of the important features of these deposits (Frietsch and Perdahl, 1995). The Arabshah Fe mineralization is the only known magnetite-apatite mineralization at the Takab–Takht-e-Soleyman–Angouran subzone within the Sanandaj-Sirjan zone which is located about 15 km southeast of Takab. During the past years, some exploration works were done on the Arabshah Fe mineralization, but its geological characteristics, mineralogy, texture, geochemistry, characteristics of mineralized fluids and genesis have not been studied yet. Recognition of characteristics of the Arabshah magnetite-apatite deposit as the first explored deposit of the Kiruna type mineralization in the Takab area is useful for exploration of this type of mineralization in NW Iran.
 
Materials and methods
This research study can be divided into two parts including field and laboratory studies. Field work includes recognition of different lithological units and ore veins along with sampling for laboratory studies. During field work, 34 samples were selected for petrographical, mineralogical and analytical studies. 10 thin sections and 5 thin-polished sections were used for petrographical and mineralogical studies. For geochemical studies, 6 samples from ore vein were analyzed by ICP–MS methods at the Geological Research Center, Karaj, Iran. Microthermometric measurements were performed on 2 samples using a Linkam THMS-600 heating–freezing stage attached to a ZIESS microscope in the fluid inclusion laboratory of the Iran Minerals Processing Research Center.
 
Results
The oldest rock units in the Arabshah area include Oligo-Miocene sedimentary succession of the Qom Formation that was intruded by the E–W-trending Pliocene Ayoub Ansar volcanic dome. Based on petrographic studies, the Ayoub Ansar volcanic dome has porphyritic, felsophyric and glomeroporphyritic textures and it is composed of plagioclase, amphibole and some quartz and K-feldspar phenocrysts set in a quartz-felspathic groundmass, and it is compositionally classified as dacite-rhyodacite. These rocks have medium-K calc-alkaline affinity and are classified as metaluminous I-type granitoids. They have been formed in an active continental margin to post-collisional tectonic setting and demonstrate geochemical characteristics similar to high silica adakites (Sabzi et al., 2018).
Fe mineralization at the Arabshah mineralization occurs as vein-veinlets of magnetite-apatite within the Ayoub Ansar dacitic dome. Brecciated zones occur at footwall and hanging wall of the main vein. The ore vein has east- west trend and crops out in 50 m length and maximum 1 m width. Coarse-grained euhedral apatite crystals are mainly present at the margins of the main vein. Hydrothermal alterations around the mineralized veins include sodic-calcic, silicification and argillic alterations. Mineralogically, the ore minerals include magnetite along with apatite, clinopyroxene, albite and quartz as gangue minerals. Goethite was formed during supergene alteration. Mineralization textures in the Arabshah deposit include vein-veinlet, brecciated, disseminated, and replacement form. Apatite crystals have high concentrations of REEs (about 1%). Condrite-normalized REE patterns for apatite crystals, magnetite-apatite ores and magnetite ore without or with minor apatite demonstrate LREE enrichment with high LREE/HREE ratio and distinctive negative Eu anomalies.
Based on phase relationships at room temperature, three types of fluid inclusion including two-phase (LV and VL), three-phase (LVH and LVS) and polyphase (LVHS) are present within the apatite crystals at the Arabshah mineralization. Microthermometric measurements indicate that LV and VL fluid inclusions have homogenized between 253-550 °C and 363-490 °C, respectively. Tree-phase LVH fluid inclusions have been homogenized between 278-508 °C and have salinities between 35-59.8 wt.% NaCl equiv. Three-phase LVS fluid inclusions have been homogenized between 240-520 °C. Polyphase LVHS fluid inclusions have been homogenized between 230-520 °C and have salinities between 36-59 wt.% NaCl equiv.
 
Discussion
Similar REE patterns of apatite crystals and mineralized samples with samples from host dacitic dome demonstrate a genetic link between magnetite-apatite mineralization and dacites. Furthermore, REE patterns of the Arabshah mineralization is similar to other iron oxide-apatite deposits from the Tarom–Hashtjin metallogenic belt (Mokhtari et al., 2018), and those of Central Iranian iron ores (Mokhtari et al., 2013). Moreover, REE patterns of the Arabshah deposit are similar to REE patterns of the Kiruna-type iron ores (Frietsch and Perdahle, 1995).
Fluid inclusion data indicates that Arabshah magnetite-apatite mineralization originated from magmatic fluids. Positive correlations between salinity and homogenization temperatures indicate that mineralization at the Arabshah deposit involved mixing of magmatic fluids and a dilute and cooler meteoric fluid.
Totally, based on mineral assemblages, hydrothermal alteration, textures, geochemical characteristics and fluid inclusion data, the Arabshah magnetite-apatite mineralization can be classified to be of the Kiruna-type iron ores.
 
Acknowledgment
This research study was made possible by a grant from the office of vice-chancellor of research and technology, University of Zanjan. We hereby acknowledge their generous support. The Journal of Economic Geology reviewers and editor are also thanked for their constructive comments.

Keywords


Asadi, S. and Khorshidian, F., 2013. Fluid inclusion microtrmometry and geochemistry of the Chadormalou deposit, evidences from IOCG mineralization in Bafq mining district. 17th Symposium of Geological Society of Iran, Shahid Beheshti University, Tehran, Iran. (in Persian with English abstract)
Asadi, S., Manouchehry Nya, M. and Hassannezhad, A.A., 2019. Origin of Choghart iron ore deposit, Central Iran: Application of the geochemistry of fluid inclusion. Journal of Advanced Applied Geology, 17(3): 59–71. (in Persian with English abstract) http://dx.doi.org/10.22055/aag.2019.28137.1918
Asadi, H.H., Voncken, J.H.L., Kühnel, R.A. and Hale, M., 1999. Invisible gold at Zarshuran, Iran. Economic Geology, 94(8): 1367–1374. https://doi.org/10.2113/gsecongeo.94.8.1367
Belousova, E., Griffin, W.L., O'Reilly, S.Y. and Fisher, N.L., 2002. Igneous zircon: trace element composition as an indicator of source rock type. Contributions to Mineralogy and Petrology 143(5): 602–622. https://doi.org/10.1007/s00410-002-0364-7
Boni, M., Gilg, H.A., Balassone, G., Schneider, J., Allen, C.R. and Moore, F., 2007. Hypogene Zn carbonate ores in the Angouran deposit, NW Iran. Mineralium Deposita, 42: 799–820. https://doi.org/10.1007/s00126-007-0144-4
Bonyadi, Z., Davidson, G.J., Mehrabi, B., Meffre, S. and Ghazban, F., 2011. Significance of apatite REE depletion and monazite inclusions in the brecciated Se–Chahun iron oxide–apatite deposit, Bafq district, Iran: Insights from paragenesis and geochemistry. Chemical Geology, 281(3–4): 253–269. https://doi.org/10.1016/j.chemgeo.2010.12.013
Boomeri, M., 2013. Rare earth minerals in Esfordi magnetite-apatite deposit, Bafq district. Scientific Quarterly Journal, Geosciences 22(85): 71–82. (in Persian with English abstract) http://dx.doi.org/10.22071/gsj.2012.54023
Buchanan, L.J., De Vivo, B., Kramer, A.K. and Lima, A., 1981. Fluid inclusion study of the Fiumarella barite deposit (Catanzaro, south Italy). Mineralium Deposita, 16: 215–226. https://doi.org/10.1007/BF00202736
Daliran, F., 2008. The carbonate rock-hosted epithermal gold deposit of Agdarreh, Takab geothermal field, NW Iran, hydrothermal alteration and mineralization. Mineralium Deposita, 43: 383–404. https://doi.org/10.1007/s00126-007-0167-x
Daliran, F., Hofstra, A.H., Walther, J. and Stüben, D., 2003. Aghdarreh and Zarshuran SRHDG deposits, Takab region, NW Iran. GSA Annual Meeting, Abstract with Programs, Session 63–8. Retrieved November 2 –5, 2003 from  https://www.agw.kit.edu/english/1427_1506.php
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. https://doi.org/10.1016/j.oregeorev.2013.02.002
Dill, H.G., 2010. The chessboard classification schome of mineral deposits: Mineralogy and geology from aluminum to zirconium. Earth-Science Reviews 100(1–4): 1–420. https://doi.org/10.1016/j.earscirev.2009.10.011
Fonoudi, M. and Hariri, A., 2000. Geological map of Takab, scale 1:100000. Geological Survey of Iran.
Forster, H. and Jafarzadeh, A., 1994. The Bafq mining district in central Iran: a high mineralized infra-Cambrian volcanic field. Economic Geology, 89(8): 1697–1721. https://doi.org/10.2113/gsecongeo.89.8.1697
Frietsch, R. and Perdahl, J.A., 1995. Rare earth elements in apatite and magnetite in Kiruna-type iron ores and some other iron ore types. Ore Geology Reviews 9(6): 489–510. https://doi.org/10.1016/0169-1368(94)00015-G
Gilg, H.A., Boni, M., Balassone, G., Allen, C.R., Banks, D. and Moore, F., 2006. Marble-hosted sulphide ores in the Angouran Zn-(Pb-Ag) deposit, NW Iran: interaction of sedimentary brines with a metamorphic core complex. Mineralium Deposita 41: 1–16. https://doi.org/10.1007/s00126-005-0035-5
Gleason, J.D., Marikos, M.A., Barton, M.D. and Johnson, D.A., 2000. Neodymium isotope study of rare earth element sources and mobility in hydrothermal Fe oxide (Fe-P-REE) system. Geochemical et Cosmochemica Acta 64(6): 1059–1068.  https://doi.org/10.1016/S0016-7037(99)00325-7
Harlov, D., Meighan, C.G., Kerr, I.D. and Samson, I.M., 2016. Mineralogy, chemistry, and fluid-aided evolution of the Pea Ridge Fe-oxide-REE deposit, southeast Missouri, USA. Economic Geology, 11(8): 1963. http://dx.doi.org/10.2113/econgeo.111.8.1963
Heidari, S.M., Daliran, F., Paquette, J.L. and Gasquet, D., 2015. Geology, timing, and genesis of the high sulfidation Au (–Cu) deposit of Touzlar, NW Iran. Ore Geology Reviews, 65: 460–486. https://doi.org/10.1016/j.oregeorev.2014.05.013
Heidari, S.M., Ghaderi, M., Kouhestani, H., 2017. Sediment-hosted epithermal gold mineralization at Arabshah, SE Takab, NW Iran. Scientific Quarterly Journal, Geosciences 27(105): 233–244. (in Persian with English abstract) http://doi.org/10.22071/gsj.2017.53971
Heidarian, H., Alirezaie, S. and Lenta, D.R., 2017. Chadormalu Kiruna-type magnetite-apatite deposit, Bafq district, Iran: Insights into hydrothermal alteration and petrogenesis from geochemical, fluid inclusion, and sulfur isotope data. Ore Geology Reviews, 83: 43–62. https://doi.org/10.1016/j.oregeorev.2016.11.031
Hildebrand, R.S., 1986. Kiruna- type deposit: their origin and relationship to inter mediate subvolcanic plutons in the Great Bear magmatic zone, Northwest Canada. Economic Geology 81(3): 640–659. https://doi.org/10.2113/gsecongeo.81.3.640
Hitzman, M.W., 2000. Iron oxide-Cu-Au deposits: What, where, when and why? In: Porter, T.M., (Editor), Hydrothermal iron oxide copper-gold and related deposits: A global perspective, 1. Australian Mineral Foundation, Adelaide, pp. 9–25. Retrieved December 3-5, 2000 from https://books.google.com/books/about/Hydrothermal_Iron_Oxide_Copper_gold_Rela.html?id=NXPxAAAAMAAJ
Hitzman, M.W., Oreskes, N. and Einaudi, M.T., 1992. Geological characteristics and tectonic setting of Protrozoic iron oxide (Cu-U-Au-LREE) deposits. Precambrian Research, 58(1): 241–287. https://doi.org/10.1016/0301-9268(92)90121-4
Jami, M., Dunlop, A.C. and Cohen, D.R., 2007. Fluid inclusion and stable isotope study of the Esfordi apatite- magnetite deposit, Central Iran. Economy Geology, 102(6): 1111–1128.  https://doi.org/10.2113/gsecongeo.102.6.1111
 Karami, F., Kouhestani, H., Mokhtari, M.A.A. and Azimzadeh, A.M., 2021. The Halab deposit, SW Zanjan: Volcanogenic massive sulfide Zn–Pb (Ag) mineralization, Takab–Takht-e-Soleyman–Angouran metallogenic district. Journal of Economic Geology, 13(1): 165–192. (in Persian with English abstract) https://dx.doi.org/10.22067/econg.v13i1.76448
Kordian, Sh., Mokhtari, M.A.A., Kouhestani, H. and Veiseh, S., 2020. Geology, mineralogy, structure and texture, geochemistry and genesis of the Golestan Abad iron oxide- apatite deposit (East of Zanjan). Journal of Economic Geology, 12(3): 299–325. (in Persian with English abstract) https://doi.org/10.22067/econg.v12i3.79628
Lecumberri-Sanchez, P., Steele-Macinnis, M. and Bodnar, R.J., 2012. A numerical model to estimate trapping conditions of fluid inclusions that homogenize by halite disappearance. Geochimica et Cosmochimica Acta, 92: 14–22. https://doi.org/10.1016/j.gca.2012.05.044
Loberg, B.E.H. and Horndal, A.K., 1983. Ferride geochemistry of Swidish Precambrian iron ores. Mineralium Deposita, 18(3): 487–504. Retrieved June 15, 2021 from https://link.springer.com/article/10.1007/BF00204493
Lotfi, M. and Karimi, M., 2004. Mineralogy and ore genesis of Bayche Bagh five elements (Ag-Ni-Co-As-Bi) vein deposit (NW Zanjan, Iran). Scientific Quarterly Journal, Geosciences, 12(53): 40–55. (in Persian with English abstract)
Maanijou, M. and Khodaie, L., 2018. Mineralogy and electron microprobe studies of magnetite in the Sarab-3 iron Ore deposit, southwest of the Shahrak mining region (East Takab). Journal of Economic Geology, 10(1): 267–293. (in Persian with extended English abstract) https://doi.org/10.22067/econg.v10i1.56522
Majidi, S.A., Lotfi, M., Emami, M.H. and Nezafati, N., 2017- The genesis of iron oxide-apatite (IOA) deposits: evidence from the geochemistry of apatite in Bafq-Saghand district, Central Iran. Scientific Quarterly Journal, Geosciences, 27(105): 233–244. (in Persian with English abstract) http://dx.doi.org/10.22071/gsj.2017.54185
Malekzadeh Shafaroudi, A. and Karimpour, M.H., 2015. Mineralization and fluid inclusion studies of the Khanlogh iron oxide- apatite deposit, noetheast Iran. Advanced Applied Geology, 17(3): 59-71. (in Persian with English abstract) http://dx.doi.org/10.22055/aag.2015.11825
McDonough, W.F. and Sun, S.S., 1995. The composition of the Earth. Chemical Geology, 120(3-4): 223–253. https://doi.org/10.1016/0009-2541(94)00140-4
Mehrabi, B., Yardley, B.W.D. and Cam, J.R., 1999. Sediment-hosted disseminated gold mineralization at Zarshuran, NW Iran. Mineralium Deposita, 34: 673–696. https://doi.org/10.1007/s001260050227
Mohammadi, Z., Ebrahimi, M. and Kouhestani, H., 2014. The Goorgoor Fe occurrence, NE of Takab: A metamorphosed volcano-sedimentary mineralization in the Sanandaj–Sirjan zone. Advanced Applied Geology, 4(13): 20–32. (in Persian with English abstract). Retrieved June 15, 2021 from  https://aag.scu.ac.ir/article_10913.html
Mohammadi Niaei, R., Daliran, F., Nezafati, N., Ghorbani, M., Sheikh Zakariaei, J. and Kouhestani, H., 2015. The Ay Qalasi deposit: An epithermal Pb–Zn (Ag) mineralization in the Urumieh-Dokhtar Volcanic Belt of northwestern Iran. Neues Jahrbuch für Mineralogie – Abhandlungen (Journal of Mineralogy and Geochemistry), 192(3): 263–274.  https://doi.org/10.1127/njma/2015/0284
Mokhtari, M.A.A., 2015. Posht-e-Badam metallogenic block (Central Iran): a suitable zone for REE mineralization. Central European Geology, 58(3): 199–216. https://doi.org/10.1556/24.58.2015.3.1
Mokhtari, M.A.A., Hossein Zadeh, Gh. and Emami, M.H., 2013. Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran) using REE geochemistry. Journal of Earth System Science, 122(3): 795–807.  https://doi.org/10.1007/s12040-013-0313-z
Mokhtari, M.A.A., Sadeghi, M. and Nabatian, Gh., 2018. Geochemistry and potential resource of rare earth element in the IOA deposits of Tarom area, NW Iran. Ore Geology Reveiws, 92: 529–541. https://doi.org/10.1016/j.oregeorev.2017.12.006
Nabatian, Gh., 2012. Geology, Geochemistry and Evolution of Iron Oxide-apatite Deposits in the Tarom Volcano-plutonic Belt, Western Alborz. Unpublished PhD Thesis, Tarbiat Modares University, Tehran, Iran, 375 pp. (in Persian with English abstract) Retrieved September 18, 2012 from https://parseh.modares.ac.ir/thesis.php?id=2032388&sid=1&slc_lang=en
Nabatian, Gh. and Ghaderi, M., 2014. Mineralogy and geochemistry of the rare earth elements in iron oxide-apatite deposits of the Zanjan region. Scientific Quarterly Journal, Geosciences, 24(93): 157–170. (in Persian with English abstract) http://dx.doi.org/10.22071/gsj.2014.43556
Nabatian, Gh., Ghaderi, M., Corfu, F., Neubauer, F., Bernroider, M., Prokofiev, V. and Honarmand, M., 2014. Geology, alteration, age and origin of iron oxide–apatite deposits in Upper Eocene quartz monzonite, Zanjan district, NW Iran. Mineralium Deposita, 49(2): 217–234. https://doi.org/10.1007/s00126-013-0484-1
Nabatian, Gh., Ghaderi, M., Daliran, F. and Rashidnejad Omran, N., 2012. Sorkhe-Dizaj iron oxide-patite ore deposit in the Cenozoic Alborz-Azarbaijan magmatic belt, NW Iran. Resource Geology, 63(1): 42–56. https://doi.org/10.1111/j.1751-3928.2012.00209.x
Najafzadeh, M., Ebrahimi, M., Mokhtari, M.A.A. and Kouhestani, H., 2017. The Arabshah occurrence: An epithermal Au-As-Sb Carlin type mineralization in the Takab-Angouran-Takht-e-Soleyman metallogenic zone, western Azerbaijan. Advanced Applied Geology, 6(4): 62–77. (in Persian with English abstract) http://doi.org/10.22055/aag.2016.12709
Nouri, F., Mokhtari, M.A.A., Izadyar, J. and Kouhestani, H., 2021. Geochemistry and petrogenesis of the Alamkandi granitoid body and Fe skarn (west of Mahneshan, Zanjan province). Journal of Economic Geology, 13(3): 507–536. (in Persian with English abstract) https://doi.org/10.22067/ECONG.V13I3.86285
Pourmohamad, F., Kouhestani, H., Azimzadeh, A.M., Nabatian, Gh. and Mokhtari, M.A.A., 2019. Mianaj iron occurrence, southwest of Zanjan: Metamorphosed and deformed volcano-sedimentary type of mineralization in Sanandaj–Sirjan zone. Scientific Quarterly Journal, Geosciences, 28(111): 161–174. (in Persian with English abstract) http://doi.org/10.22071/gsj.2017.84283.1099
Roedder, E., 1984. Fluid inclusions. Mienralogical Society of America, Virginia, 646 pp.
Sabzi, Z., Mokhtari, M.A.A. and Ebrahimi, M., 2018. Petrology and geochemistry of Ayoub Ansar volcanic dome, southeast Takab. Researches in Earth Sciences, 9(1): 103–117. (in Persian with English abstract) Retrieved June 15, 2021 from https://esrj.sbu.ac.ir/article_96554.html?lang=en
Shepherd, T.J., Rankin, A.H. and Alderton, D.H.M., 1985. A practical guide to fluid inclusion studies. Blackie, Glasgow, 239 pp. http://doi.org/10.1180/minmag.1986.050.356.32
Steele-MacInnis, M., Lecumberri-Sanchez, P. and Bodnar, R.J., 2012. HOKIEFLINCS-H2O-NaCl: A Microsoft Excel spreadsheet for interpreting microthermometric data from fluid inclusions based on the PVTX properties of H2O-NaCl. Computers and Geosciences, 49: 334–337. https://doi.org/10.1016/j.cageo.2012.01.022
Sterner, S.M., Hall, D.L. and Bodnar, R.J., 1988. Synthetic fluid inclusions. V. Solubility relations in the system NaCl-KCl-H2O under vapor-saturated conditions. Geochimica et Cosmochimica Acta 52, 989–1005. https://doi.org/10.1016/0016-7037(88)90254-2
Tofigi, F., Mokhtari, M.A.A., Izadyar, J. and Kouhestani, H., 2019. Geology and genesis of Halab 2 Fe occurrence in Takab-Takht-e-Soleiman-Anguoran metallogenic zone. Advanced Applied Geology, 8(1): 44–59. (in Persian with English abstract) http://doi.org/10.22055/aag.2018.22926.1747
Torab, F.M. and Lehmann, B., 2008. Magnetite-apatite deposits of the Bafq district, Central Iran: apatite geochemistry and monazite geochronology. Mineralogical Magazine, 71(3): 347–363. https://doi.org/10.1180/minmag.2007.071.3.347
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  
Wilkinson, J.J., 2001. Fluid inclusions in hydrothermal ore deposits. Lithos, 55(1–4): 229–272. https://doi.org/10.1016/S0024-4937(00)00047-5
 
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