Rare Earths in fluorite deposits of Elika Formation (East of Mazandaran Province)

زمین شناسی اقتصادی

Article 7, Volume 8, Issue 1 - Serial Number 14, June 2016, Pages 201-221   

Document Type: Research Article

DOI: 10.22067/econg.v8i1.29969

Authors

Zahra Mehraban; Behnam Shafiei Bafti^* ; Gholam Hossein Shamanian

Golestan

Abstract

Introduction
The Central Alborz in eastern Mazandaran province is host to the most important carbonate-hosted fluorite deposits in Iran, such as Pachi-Miana, Sheshroodbar, Era and Kamarposht. In these deposits, mineralization occurs in the upper parts of the middle Triassic Elika formation (Vahabzadeh et al., 2009 and references therein). These deposits have long been studied, and various models are presented for ore genesis. Nevertheless, ore genesis in these deposits is still unclear. The present study of the geochemistry of the REEs of these deposits is intended to improve genetic models.

Materials and methods
Three hundred samples were taken from above mentioned deposits. Samples were categorized into 5 groups: (1) fluorite ore types, (2) ore-stage calcite, (3) carbonate host rocks, (4) basaltic rock around the deposits, and (5) shale of the Shemshak formation. Fourteen pure fluorite samples, 4 samples of pure calcite, 4 samples of carbonate host rock, 1 sample of basalt and 1 sample of shale were analyzed for REEs by ICP-MS at West Lab in Australia.

Results
Analytical data on fluorite from the Elika deposits show very low REE concentrations (0.5-18ppm), in calcite(0.5-3ppm) in carbonate host rocks – limestone (1.8-7ppm), and in dolomitic limestone 6.5ppm, compared with upper Triassic basalt (43ppm) and shale (261ppm). REE in fluorite of these deposits are strongly enriched (10 3 to 10 6 times) relative to normal sea water, ore stage calcite and carbonate host rocks, especially for mid-REEs (Eu, Gd) and heavy REEs (Lu, Yb, La/Yb=~0.05).
Also, LREEs depletion (La/Sm= 2-10) and HREEs (La/Yb=0.01-0.08) relatively enrichment of fluorites compared with limestone (La/Sm=2.5-4, La/Yb=0.1-1.5) and dolomitic limestone (La/Sm=4.28, La/Yb=0.07-0.4) host rocks as well as positive Eu anomaly are the most important REEs signatures in fluorites.
Fluorite elsewhere in the world with low total REE conten thas been interpreted to have a sedimentary origin (Ronchi et al., 1993; Hill et al., 2000; Sasmaz et al., 2005). Strong enrichment of REEs in fluorite and carbonate host rocks worldwide, relative to normal sea water indicates that diagenetic and/or hydrothermal processes have contributed to the process. Depletion of LREEs and moderately strong HREE enrichment in fluorite relative to carbonate host rocks is interpreted to be post-sedimentation (Ronchi et al., 1993;Hill et al., 2000). Thisis supported by the hydrothermal character of the fluorite in the Elika deposits and similarity between REE profiles and those of fluorine-rich MVT deposits with hydrothermal origin (Chesley et al.,1994; Bau et al., 2003). Positive Eu anomalies in fluorite elsewhere suggest deposition reduced conditions and temperatures~250°C (Bau et al., 2003; Sverjensky, 1989). The present study indicates that low total REEcontents in fluorite precipitated from reduced hydrothermal solutions could be caused by (1) increasing pH of the ore-forming solution during interaction with carbonate host-rock, (2) gradually decreasing F concentration in hydrothermal solutions due to different generations of fluorite mineralization, and (3) low REE contents of carbonate hostrocks.

References
Bau, M., Romer, R.L., Luders, V. and Dulski, P., 2003. Tracing element sources of hydrothermal mineral deposits: REE and Y distribution and Sr-Nd-Pb isotopes in fluorite from MVT deposits in the Pennine Orefield, England. Mineralium Deposita, 38(8): 992–1008.
Chesley, J.T., Halliday, A.N., Kyser, T.K. and Spry, P.G., 1994. Direct Dating of MississipValley-type mineralization: Use of Sm-Nd in fluorite. Economic Geology, 89(9):1192-1199.
Hill, G.T., Campbell, A.R., and Kyle, P.R., 2000. Geochemistry of southwestern New Mexico fluorite occurrences: implications for precious metals exploration in fluorite-bearing systems. Journal of Geochemical Exploration, 68(1): 1–20.
Ronchi, L.H., Touray, J.C., Michard, A. and Dardenne, M.A., 1993. The Riberia fluorite district, Southern Brazil. Geological and geochemical (REE, Sm–Nd isotopes) characteristics. Mineralium Deposita, 28(1): 40–52.
Sasmaz, A., Yavuz, F., Sagiroglu, A. and Akgul, B., 2005. Geochemical patterns of the Akdagmadeni (Yozgat, Central Turkey) fluorite deposits and implications. Journal of Asian Earth Sciences, 24 (3): 469–479.
Sverjensky, D.A., 1989. The diverse origins of Mississippi Valley-type Zn–Pb–Ba–F deposits. Chronicle of mineral research and exploration, 495(1): 5 – 13.
Vahabzadeh, G., Khakzad, A., Rasa, I. and Mosavi, M.R., 2009. Study on S isotopes in galena and barite of Savad Kuh fluorite deposits. Journal of Basic Science, Islamic Azad University, 69(18): 99-108 (in Persian).

Keywords

Rare Earth Elements (REEs); Fluorite; Elika; Mazandaran

References

Aghanabati, S.A., 2005. Geology of Iran. Geological Survey of Iran Publication, Tehran, 586 pp (in Persian).

Alirezaee, S., 1989. Contribution to stratigraphy and mode of generation of F-Pb-Ba deposits in Triassic of eastern Alborz. M.Sc. Thesis, Tehran University, Tehran, Iran, 87 pp (in Persian).

Bau, M., Romer, R.L., Luders, V. and Dulski, P., 2003. Tracing element sources of hydrothermal mineral deposits: REE and Y distribution and Sr-Nd-Pb isotopes in fluorite from MVT deposits in the Pennine Orefield, England. Mineralium Deposita, 38(8): 992–1008.

Bonsall, T.A., Spry, P.G., Voudouris, P.C.H., Tombros, S., Seymour, K.St.‌ and Melfos, V., 2011. The Geochemistry of Carbonate-Replacement Pb-Zn-Ag Mineralization in the Lavrion District, Attica, Greece: Fluid Inclusion, Stable Isotope and Rare Earth Element Studies. Economic Geology, 106(5): 619–651.

Brunet, M.F., Granath, J.W.‌ and Wilsmen, M., 2009. South Caspian to Central Iran Basins. The Geological Society London Special Publications, 312(2): 1-6.

Chesley, J.T., Halliday, A.N., Kyser, T.K. and Spry, P.G., 1994. Direct Dating of MississipValley-type mineralization: Use of Sm-Nd in fluorite. Economic Geology, 89(9):1192-1199.

Constantopoulos, J., 1988. Fluid inclusion and REE geochemistry of fluorite from south-central Idaho. Economic Geology, 83(5): 626–636.

Dill, H. G. Hansen, B.T.‌ and Weber, B., 2011. REE contents, REE minerals and Sm/Nd isotopes of granite-and unconformity-related Fluorite mineralization at the western edge of the Bohemian Massif: With special reference to the Nabburg-Wölsendorf District, SE Germany. Ore Geology Reviews, 40(1): 132–148.

Ehya, F., 2012. Variation of mineralizing fluids and fractionation of REE during the emplacement of the vein-type fluorite deposit at Bozijan, Markazi Province, Iran. Journal of Geochemical Exploration, 112(1): 93–106.

Ekambaram,‌V., Brookins, D.G., Rosenberg, P.E.‌‌ and Emanuel, K.M., 1986. Rare earth element geochemistry of fluorite-carbonate deposits in western Montana, U.S.A. Chemical Geology, 54(2): 319-331.

Eppinger, R.G, and Closs L.G., 1990. Variation of trace elements and rare earth elements in fluorite, a possible tool for exploration. Economic Geology, 85(10): 1896–1907.

Fisher, J., Lillie, R.‌ and Rakovan, J., 2013. Flourite in Mississippi Valley-Type Deposits. Rocks and Minerals, 88(1): 20-47.

Gorjizad, H., 1996. Study on geology, mineralogy, facies analysis and genesis of Pachi Miana fluorite deposit. M.Sc. Thesis, Tarbiat Modaress University, Tehran, Iran, 156 pp.

Henderson, P., 1984. Rare earth element geochemistry, Developments in Geochemistry. Elsevier Science Publishers, Amsterdam, 2510 pp.

Hill, G.T., Campbell, A.R., and Kyle, P.R., 2000. Geochemistry of southwestern New Mexico fluorite occurrences: implications for precious metals exploration in fluorite-bearing systems. Journal of Geochemical Exploration, 68(1): 1–20.

Joseph, L.‌ and Graf, Jr., 1984. Effects of Mississippi Valley-Type Mineralization on REE Patterns of Carbonate Rocks and Minerals, Viburnum Trend, Southeast Missouri. The Journal of Geology, 92(3): 307-324.

Moller, P., Bau, M., Dulski, P.‌ and Lüders, V.,1998. REE and Y Fractionation in Fluorite and Their Bearing on Fluorite Formation. Proceedings of the Ninth Quadrennial IAGOD Symposium, Schweizerbart, Stuttgart.

Moller, P., Parekh, P.P. and Schneider, H.J., 1976. The application of Tb/Ca–Tb/La abundance ratios to problems of fluorspar genesis. Mineralium Deposita, 11(1): 111– 116.

Palmer, D.A. S and Williams-Jones, A.E., 1996. Genesis of the carbonatite hosted fluorite deposit at Amba Dongar, India: Evidence from fluid inclusions, stable isotopes and whole rock-mineral geochemistry. Economic Geology, 91(8): 934–950.

Rollinson, H., 1993. Using geochemical data: evaluation, presentation, interpretation. Longman Publisher, UK, 352 pp.

Ronchi, L.H., Touray, J.C., Michard, A.‌ and Dardenne, M.A., 1993. The Riberia fluorite district, Southern Brazil. Geological and geochemical (REE, Sm–Nd isotopes) characteristics. Mineralium Deposita, 28(1): 40–52.

Sanchez, V., Cardellach, E., Corbella, M., Vindel, E., Crespo, T.M.‌ and Boyce, A.J., 2010. Variability in fluid sources in the fluorite deposits from Asturias (N Spain): Further evidences from REE, radiogenic (Sr, Srn, Nd) and stable (S, C, O) isotope data. Ore Geology Reviews, 37(1): 87–100.

Sasmaz, A., Yavuz, F., Sagiroglu, A.‌ and Akgul, B., 2005. Geochemical patterns of the Akdagmadeni (Yozgat, Central Turkey) fluorite deposits and implications. Journal of Asian Earth Sciences, 24 (3): 469–479.

Schönenberger, J., Köhler, J.‌ and Markl, G., 2008. REE systematics of fluorides, calcite and siderite in peralkaline plutonic rocks from the Gardar Province, South Greenland. Chemical Geology, 247(1): 16–35.

Schwinn, G. and Markl, G., 2005. REE systematics in hydrothermal fluorite. Chemical Geology, 216(2): 225– 248.

Shariatmadar, A., 1999. Geology and genesis of Sheshrodbar fluorite deposit. M.Sc. Thesis, Tarbiat Modaress University, Tehran, Iran, 230 pp (in Persian).

Souissi, F., Souissi, R.‌ and Dandurand, J.L., 2010. The Mississippi Valley-type fluorite ore at Jebel Stah (Zaghouan district, north-easternTunisia): Contribution of REE and Sr isotope geochemistry to the genetic model. Ore Geology Reviews, 37(1):15–30.

Sverjensky, D.A., 1989. The diverse origins of Mississippi Valley-type Zn–Pb–Ba–F deposits. Chronicle of mineral research and exploration, 495(1): 5 – 13.

Tabasi, H., 1997. Structural analysis of Sheshrodbar fluorite mine. M.Sc. Thesis, Tarbiat Modaress University, Tehran, Iran, 130 pp (in Persian).

Vahabzadeh, G., 2008. Comparison between mineralogy, geochemistry and genesis of fluorite deposits of Savad Kuh region. Ph.D. Thesis, Shahid Beheshti University, Tehran, Iran, 174 pp (in Persian).

Vahabzadeh, G., Khakzad, A., Rasa, I.‌ and Mosavi, M.R., 2008. Oxygen and Carbon Isotopes and REE Study in the Emaft Fluorite Mine, Savad Kuh Region (Mazandaran province). Research Journal of Isfahan University, 29(3): 189-200 (in Persian).

Vahabzadeh, G., Khakzad, A., Rasa, I.‌ and Mosavi, M.R., 2009. Study on S isotopes in galena and barite of Savad Kuh fluorite deposits. Journal of Basic Science, Islamic Azad University, 69(18): 99-108 (in Persian).

Williams-Jones, A.E., Samson, I.M.‌ and Olivo, G.R., 2000. The genesis of hydrothermal fluorite-REE deposits in the Gallinas Mountains, New Mexico. Economic Geology, 95(2):327–342.