Crystal chemistry of phlogopite minerals from Plio-Quaternary potassic volcanic rocks, NW Marand

Abstract

Plio-Quaternary potassic to high potassic basaltic rocks are found in northern part of Uromieh-Dokhtar Magmatic Arc in NW Iran. The mineralogical composition of these rocks characterized with phenocrysts of Cpx, phlogopite, leucite and olivine in groundmass of plagioclase, sanidine, Cpx and biotite. Phlogopite phenocrysts display a euhedral platy form with reaction rims. Based on the International Mineralogical Association scheme, the phologopite compositions plot between siderophyllite and eastonite end members and show Fe/(Fe+Mg) ratios<0.33. Based on their TiO2, MgO, MnO and AlVI content, they are primary magmatic micas. The micas contain up to 5 wt% BaO and 8.62 wt% TiO2 and indicate similarity in composition with barian titanian phlogopites from other potassic volcanic rocks in the world. As BaO, Al2O3 and TiO2 increase, the SiO2, FeO, MgO and K2O decrease. In this regard, Different substitutions deduced from such variations, which is common to most magmatic barian micas are discussed. In comparison with other potassic and high potassic volcanic rocks, the studied phlogopites display similarity with phlogopites of Italian Roman type volcanic rocks.

Keywords


[1] Mitchell R.H., “Titaniferous phlogopites from the Leucite lamproites of the West Kimberley area, Western Australia”, Contributions to Mineralogy and Petrology 76 (1981) 243-25l.

[2] Zhang M., S uddaby P, Thompson R. N., Dungan M. A., “Barian-titanian phlogopite from potassic lavas in northeast China: chemisry, substitutions and paragenesis”, Am.Mineral 78 (1996) 1056-1065.

[3] Holm P.M., “Mineral chemistry of perpotassic lavas of the Vulsinian district, the Roman Province, Italy,” Mineralogical Magazine 46 (1982) 379-386.

[4] O'Brien H.E., Irving A., McCallum I.S., “Complex zoning and resorption of phenocrysts in mixed potassic mafic magmas of the High-wood Mountains, Montana,” American Mineralogist 73 (1988) l007-1024.

[5] Feldstein S.N., Lange R.A., Vennemann T., O’Neil J.R., “Ferric–ferrous ratios, H2O contents and D/H ratios of phlogopite and biotite from lavas of different tectonic regimes,” Contribution to Mineralogy and Petrology, 126 (1996) 51–66.

[6] Ahmadzadeh G., Jahangiri A., lentz D., Mojtehdi M., “Petrogenesis of Plio-Quaternary post-collisional ultrapotassic volcanism in NW of Marand, NW Iran”, Journal of Asian Earth Sciences 39 (2010) 37-50.

[7] Rieder M., Cavazzini G., Yakonov, Y.D., Frank-Kanetskii, V.A., Gottardi, G., Guggenheim S., Koval P.V., Muller G., Neiva A.M.R., Radoslovich, E.W., Robert, J.L., Sassi, F.P., Takeda, H., Weiss, Z., Wones, D.R.,. “Nomenclature of the micas,” Canadian Mineralogist 36 (3) 1998 905–912.

[8] Guo J., Green T.H., "Experimental study of barium partitioning between phlogopite and silicate liquid at upper-mantle pressure and temperature”, Lithos 24, (1990) 83-95.

[9] Dymek R.F., “Titanium, aluminum and interlayer cation substitutions in biotite from high-grade gneisses, west Greenland,” American Mineralogist 68 (9–10) (1983) 880–899.

[10] Nachit H., Ibhi A., Abia E.H., Ohoud M.B., “discrimination between primary magmatic biotites, reequilibrated biotites and neoformed biotites”, Geomateriala (Mineralogy), Comptes Rendus, Geosciences 337 (2005) 1415-1420

[11] Farmer G.L., Boettcher A.L., “Petologic and crystal-chemical significance of some deep-seated phlogopites”, Am. Mineral.66, (1981)1154-1163.

[12] Bol L.C.G.M., Bos A., Sauter P. C.C., Jansen J.B.H., “Barium-titanium-rich phlogopites in marbles from Rogaland, southwest Norway,” American Mineralogist 74, (1989) 439-447.

[13] Deer W.A., Howie R.A., Zussman J., “Rock-forming minerals”, III. Sheet silicates, p. 42-54. (1962) Longmans, London.

[14] Foley S.F., “Experimental constraints on phlogopite chemistry in lamproites. II Effect of pressure-temperature variations”, European Journal of Mineralogy 2 (1990) 327-341

[15] Mansker W.L., Ewing R.C., Keil K., “Barian-titanian biotites in nephelinites from Oahu, Hawaii”, American Mineralogist 64 (1979) 156-I 59.

[15] Mitchell R.H., Bergman S.C., “Petrology of lamproites”, p. 169-217 (1991) Plenum Press, New York.

[16] Forbes W.C., FLower M.J.F., “Phaser elations of titan-phlogopite, K2Mg4TiAl2Si6O20 (OH)4: a refraclory phase in the upper mantle”, Earth Planet. Sci. Iett. 22 (1974) 60-66.

[17] Robert J.-L., “Titanium solubility in synthetic phlogopite solid solutions”, Chem. Geol. 17 (1976) 213-227.

[18] Barton M., “A comparative study of some minerals occurring in the potassium-rich alkaline rocks of the Leucite Hills, Wyoming, the Vico Volcano, Western Italy, and the Toro-Ankole Region, Uganda”, Neues Jahrbuch fiir Mineralogie Abhandlungen, 137, (1979) ll3-134.

[19] Edgar A.D., “Mineral chemistry and petrogenesis of an ultrapotassic-ultramafrc volcanic rock”, Contributions to Mineralogy and Petrology, 7l (1979) 17l-175

[20] Thompson R.N., “Primary basalts and magma genesis. III. Alban Hills, Roman comagmatic province, central Italy”, Contributions to Mineralogy and Petrology 60 (1977) 9l-108.

[21] Holm P.M., “Mineral chemistry of perpotassic lavas of the Vulsinian district, the Roman Province, Italy”, Mineralogical Magazine 46 (1982) 379-386.

[22] Bachinski S.W., Simpson E.L., “Ti-phlogopites of the Shaw's Cove minette: A comparison with micas of other lamprophyres, potassic rocks, kimberlites, and mantle xenoliths”, American Mineralogist 69 (1984) 4t-56.

[23] Ryabchikov I.D., Kovalenko V.I., Dikov Yu P., Vladykin N.V., “Titaniferous micas from the mantle: Composition, structure, formation conditions, and possible role in the production of potassic alkali magmas”, Geokhimiya 6 (1981) 873-888.

[24] Carlier G., Lorand J.P., Audebaud E., Kienast J.R., “Petrology of unusual orthopyroxene-bearing minette suite From southeastern Peru, Eastern Andean Cordillera: Al-rich lamproites contaminated by peraluminous granites”, J. Volcanol. Geotherm. Res. 75 (1997) 59–87.