Geochemistry of rare earth elements in the Baba Ali magnetite skarn deposit, western Iran – a key to determine conditions of mineralisation
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Keywords

Almoughlagh
Ce/Ce* ratio
Eu/Eu* ratio
La/Y ratio

How to Cite

Zamanian, H., & Radmard, K. (2016). Geochemistry of rare earth elements in the Baba Ali magnetite skarn deposit, western Iran – a key to determine conditions of mineralisation. Geologos, 22(1), 33–47. https://doi.org/10.1515/logos-2016-0003

Abstract

The Baba Ali skarn deposit, situated 39 km to the northwest of Hamadan (Iran), is the result of a syenitic pluton that intruded and metamorphosed the diorite host rock. Rare earth element (REE) values in the quartz syenite and diorite range between 35.4 and 560 ppm. Although the distribution pattern of REEs is more and less flat and smooth, light REEs (LREEs) in general show higher concentrations than heavy REEs (HREEs) in different lithounits. The skarn zone reveals the highest REE-enriched pattern, while the ore zone shows the maximum depletion pattern. A comparison of the concentration variations of LREEs (La–Nd), middle REEs (MREEs; Sm–Ho) and HREEs (Er–Lu) of the ore zone samples to the other zones elucidates two important points for the distribution of REEs: 1) the distribution patterns of LREEs and MREEs show a distinct depletion in the ore zone while representing a great enrichment in the skarn facies neighbouring the ore body border and decreasing towards the altered diorite host rock; 2) HREEs show the same pattern, but in the exoskarn do not reveal any distinct increase as observed for LREEs and MREEs. The ratio of La/Y in the Baba Ali skarn ranges from 0.37 to 2.89. The ore zone has the highest La/Y ratio. In this regard the skarn zones exhibit two distinctive portions: 1) one that has La/Y >1 beingadjacent to the ore body and; 2) another one with La/Y < 1 neighbouring altered diorite. Accordingly, the Baba Ali profile, from the quartz syenite to the middle part of the exoskarn, demonstrates chiefly alkaline conditions of formation, with a gradual change to acidic towards the altered diorite host rocks. Utilising three parameters, Ce/Ce*, Eu/Eu* and (Pr/Yb)n, in different minerals implies that the hydrothermal fluids responsible for epidote and garnet were mostly of magmatic origin and for magnetite, actinolite and phlogopite these were of magmatic origin with low REE concentration or meteoric water involved.

https://doi.org/10.1515/logos-2016-0003
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References

Amiri, M., 1995. Petrography of the Almouglagh. University of Tarbiat-e-Moalem, Tehran, Iran, 231 pp. (in Persian)

Asadi, S., 2009. Study of iron mineralization in metamorphic rock in Kohe germez – Kohe sorkh (Qatruyeh). University of Shiraz, Shiraz, Iran, 154 pp. (in Persian)

Aubert, D. Stille, P. & Probst, A., 2001. REE fractionation during granite weathering and removal by waters and suspended loads: Sr and Nd isotopic evidence. Geochimica et Cosmochimica Acta 65, 387–406.

Barud, J., 1975. Geological Map of the Kermanshahan Quadrangle (1:250,000). Geological Survey of Iran, Tehran.

Bellon, H. & Barud, J., 1975. Donnes nouvellexs sur le domaine metamorphique du Zagros (Zone de S-S au niveau de Kermanshah-Hamadan (Iran); Nature, age et interpretation des series metamorphiques et des intrusious, evolution structurale. Faculty of Science, Orsay Paris, 14 pp. (in French)

Brooking, D.G., 1984. Geochemical aspects of radioactive waste disposal. Springer, New York, 374 pp.

Crinci, J. & Jurkowic, I., 1990. Rare earth elements in Triassic bauxites of Croatia Yugoslavia. Travaux 19, 239–248.

Darvishzadeh, A., 1992. Geology of Iran. Nashre Danesh, Tehran, Iran, 901 pp. (in Persian)

Einaudi, M.T. Meinert, L.D. & Newberry, R.J., 1981. Skarn Deposits. Economic Geology, 75th Anniversary Volume, 317–391.

Emami, M.H., 2000. Magmatism in Iran. Geological Survey of Iran, Tehran, Iran, 608 pp. (in Persian)

Frei, D., Liebscher, A., Wittenberg, A. & Shaw, C.S.J., 2003. Crystal chemical controls on rare earth element partitioning between epidote-group minerals and melt: An experimental and theoretical study. Contributions to Mineralogy and Petrology 146, 192–204.

Green, G.R. Ohmoto, H. Date, J. & Takahashi, T., 1983. Whole-rock oxygen isotope distribution in the Fukazawa–Kosaka area, Hokuroku district, Japan and its potential application to mineral exploration. Economic Geology. Monogr. 5, 395–411.

Hashiguchi, H. Yamada, R. & Inoue, T., 1983. Practical application of low Na2O anomalies in footwall acid lava for delimiting promising areas around the Kosaka and Fukazawa Kuroko deposits, Akita Prefecture, Japan. Economic Geology. Monogr. 5, 387–394.

Ishihara, S., 1981. The Granitoid Series and mineralization. Economic Geology 75, 458–484.

Ishikawa, Y. Sawaguchi, T. Iwaya, S. & Horiuchi, M., 1976. Delineation of prospecting targets for Kuroko deposits based on modes of volcanism of underlying dacite and alteration halo. Mining Geology 26, 105–117.

Karadag, M. Kupeli, S. Aryk, A. Ayhan, A. Zedef, V. & Doyen, A., 2009. Rare earth elements (REE) geochemistry and genetic implications of the Mortas bauxite deposit (Seydisehir/Konya-Southern Turkey). Chemie der Erde Geochemistry 69, 143–159.

Kato, Y., 1999. Rare earth elements as an indicator to origins of skarn deposits, example of the Kamioka Zn-Pb and Yoshiwara-Sannotake (Cu-Fe) deposit in Japan. Resource Geology 49, 183–198.

Kikawada, Y., 2001. Experimental studies on the mobility of lanthanides accompanying alteration of andesite by acidic hot spring water. Chemical Geology 176, 137–149.

Knarchenko, S.M. & Pokrovsky, B.G., 1995. The tomtor alkaline ultrabasic massif and related REE-Nb deposit, Northern Siberia. Economic Geology 90, 676–689.

Pollard, P.J., 1995. A special issue devoted to the geology of rare metal deposits, geology of rare metal deposits: An introduction and overview. Economic Geology 90, 489–494.

Rard, J.A., 1988. Aqueous solubility’s of praseodymium, Europium and lutetium sulfates. Journal of Solution Chemistry 17, 499–517.

Ramdohr, P., 1980. The ore minerals and their intergrowth. 2nd ed. Pergamon Press, London, 1205 pp.

Rolland, Y. Cox, S. Boullier, A. & Pennacchioni, G., 2003. Rare earth and trace element mobility in mid-crustal shear zones: insights from the Mont Blanc Massif (Western Alps). Earth and Planetary Science Letters 214, 203–219.

Rollinson, H., 1993. Using Geochemical data: Evolution, presentation, interpretation. Longman, London, 652 pp.

Taylor, Y. & McLennan, S.M., 1985. The Continental Crust: Its Composition and Evolution. Blackwell, Oxford, 312 pp.

Wood, S.A., 1990. The aqueous geochemistry of the rare-earth elements and Yttrium. Theoretical predictions of speciation in hydrothermal solutions to 350°C at saturation water vapor pressure. Chemical Geology 88, 99–125.

Yusoff, Z.M., Ngwenya, B.T. & Parsons, I., 2013. Mobility and fractionation or REE during deep weathering of geochemically contrasting granites in a tropical setting, Malaysia. Chemical Geology 349–350, 71–86.

Zamanian, H., 2003. Iron mineralization related to the Almoughlagh and south Ghorveh batholiths with specific refrence ti the Baba Ali and Gelali deposits. University of Pune, 220 pp.

Zamanian, H. & Asadollahi, B., 2013. Geochemistry and ore potential of the Almoughlagh batholiths, Western Iran. Geologos 19, 229–242.