Study of pegmatites from Ebrahim Attar and related skarns (southwest of Qorveh)

Abstract

The study area is located in west of Iran (38 km SW of Qorveh). This region is part of Sanandaj-Sirjan zone. This area contains several pegmatitic dikes and based on mineralogical and geochemical characteristics belong to muscovite-rare-element pegmatites. The lithology of this body varies from pegmatitic syenogranite to granodiorite. Various rock bodies in this suite are mostly I-type and calc-alkaline, with moderate to high K and regarding to the aluminum saturation degree they are subaluminous to peraluminous. The low (La/Yb) N ratio in the pegmatitic samples (2.28) indicates progression of fractional crystallization in the initial magma. The low Eu/Eu* ratio (0.137) in these pegmatites indicates differentiation of calcic plagioclase before pegmatitic stage. In the spider diagrams, LILE elements such as K, Rb and Th are enriched relative to HFSE elements specially Nb and Ti. Intrusion of this pegmatite in the carbonate rocks led to skarn development. These skarns have different minerals such as tremolite, epidote, scapolite, clinozoisite, pyrrhotite, pyrite, chalcopyrite and magnetite. Based on geochemical characteristics of these pegmatites, their composition, in accordance with bodies, is related to Sn, W and Mo skarns. This fact is in agreement with the studies in area regarding Sn & W mineralization.

Keywords


[1] London D., “Granitic pegmatites”, Trans. Royal Soc. Edinb.: Earth Sci 87 (1996) 305-319.

[2] London D., “Estimating abundances of volatile and other mobile components in evolved silicic melts through mineral melt equilibria”, Journal of Petrology 38 (1997) 1691-1706.

[3] London D., “Granitic pegmatites: an assessment of current concepts and directions for the future”, Lithos 80 (2005) 281-303.

[4] عمیدی س. م.، "تحقیق سنگ شناسی آذرین جنوب شهرستان قروه" ، پایان نامه کارشناسی ارشد، دانشگاه تهران (1345) 60 ص.

[5] حسینی م.، " شرح نقشه زمین‌شناسی 1:100000 چهار گوش قروه (پیوست نقشه)"، سازمان زمین‌شناسی و اکتشافات معدنی کشور (1376).

[6] ترکیان ا.، "مطالعه ماگماتیسم توده گرانودیوریتی منطقه جنوبی قروه"، پایان نامه دکتری، دانشگاه اصفهان (1387) 135ص.

[7] گردیده س.، "پترولوژی مجموعه آذرین و دگرگونی منطقه مشیرآباد- تازه آباد (جنوب قروه- کردستان)"، پایان نامه کارشناسی ارشد، دانشگاه بوعلی‌سینا (1389) 154ص.

[8] دانشور ن.، "بررسی لیتوژئوشیمی کانی‌زایی تنگستن ابراهیم عطار (جنوب غرب قروه)، پایان نامه کارشناسی ارشد، دانشگاه تربیت معلم (1390) 261ص.

[9] Hildreth W., “Gradients in silicic magma chambers: implications for lithospheric magmatism”, Journal of Geophysical Research 86 (1981) 10153-10192.

[10] Du Bray E.A., “Garnet compositions and their use as indicators of granitoid petrogenesis – southeastern Arabian shield”, Contribution to Mineralogy and Petrology 100 (1988) 205-212.

[11] Green T. H., “Garnet in silicic liquid and its possible use as P-T indicator”, Contribution to Mineralogy and Petrology 65 (1977) 59-67.

[12] London D., Evensen J. M., “Beryllium in Silicic magamas and the origin of beryl-bearing pegmatite”. In: Grew, E.S. (Ed.), Beryllium: Mineralogy Petrology and Geochemistry, Mineralogical Society of America, Review in Mineralogy and Geochemistry (2003) 455-486.

[13] Passchier C. W., Trouw R. A. J., “Microtectonics”, Springer-Verlag, Berlin, Heidelberg (1996) 289p.

[14] Cerny P., Ercit T. S., “The classification of granitic pegmatites revisited”, The Canadian Mineralogist 43 (2005) 2005-2026.

[15] Shmakine B. M., “Muscovite and Rare Metal-Muscovite pegmatites”, Nauka, Novosibirsk, USSR (in Russ) (1976).

[16] Ercit T. S., “REE enriched granitic pegmatites”, In: Linnen R.L., Samson I.M., (eds.) Rare element Geochemistry and Mineral Deposits, Geological Association of Canada, Short Course Notes 17 (2005) 175-199.

[17] Wood P. A., “Petrogenesis of the Spruce Pine pegmatites, North Carolina”, M. Sc. Thesis, Virginia Polytechnic Institute, Blacksburg, Virginia, USA (1996).

[18] سلامی ص.، "مطالعه پگماتیت‌های ابراهیم عطار با تاکید بر انواع بریل‌دار (جنوب قروه)" ، پایان نامه کارشناسی ارشد، دانشگاه بوعلی‌سینا (1390) 134ص.

[19] Middlemost E. A. K., “Magmas and magmatic rocks, an introduction to igneous petrology”, Longman Groupuk (1985).

[20] Maniar P. D., Piccoli P. M., “Tectonic discrimination of granitoids”, Geological Society of America Bulletin 101 (1989) 635-643.

[21] Irvine T. N., Baragar W. R. A., “A guide to the chemical classification of common volcanic rocks”,Can. Journal of Earth Science 8 (1971) 523-484.

[22] Miyashiro A., “Volcanic rock series in island arcs and active continental margins”, American Journal of Science, 274 (1974) 321-355.

[23] Rickwood P. C., “Boundary lines within petrologic diagrams which use oxides of major and minor elements”, Lithos 22 (1989) 247-263.

[24] Collins W. J., Beams S. D., White A. J. R., Chappel B. W., “Nature and Origin of A-Type Granites with Particular Refernce to Southeastern Australia”, Contributions to Mineralogy and Petrology 80 (1982) 189-200.

[25] Boynton W. V., “Cosmochemistry of the rare earth elements: meteorite studies, Rare Earth Elements Geochemistry”, Elsevier, Amsterdam (1984) 63-114.

[26] Tepper J. H., Nelson B. K., Bergantz G. W., Irving A. J., “Petrology of the Chiliwack Batholith, North Cascades, Washington: generation of calc-alkaline granitoids by melting of mafic lower crust with variable water fugacity”, Contributions to Mineralogy and petrology 113 (1993) 333-351.

[27] Sun S. S., McDonough W. F., “Chemical and isotopic systematics of oceanic basalts: Implications for mantel composition and processes. In: Saunders, A. D., and Norry, M. J., eds., Magmatism in Ocean Basins”, Geological Society of London, Special Publication 42 (1989) 313-345.

[28] Floyd P. A., Winchester J. A., “Magma type and tectonic setting discrimination using immobile elements”, Earth and Planetary Science Letters 27 (1975) 211-218.

[29] Bucher K., Frey M., “Petrogenesis of metamorphic Rocks”, Springer Verlag (1994).

[30] Meinert L. D., “Variability of skarn deposits-guides to exploration”, In: Boardman, S.J. (Ed.) Revolution in the Earth Sciences. Kendall-Hunt Publishing, Dubuque, lowa (1983) 301-316.

[31] Meinert L. D., “Igneous petrogenesis and skarn deposits”, Geological Association of Canada Special Paper 40 (1993) 569-583.









[32] Meinert L. D., “Compositional variation of igneous rocks associated with skarn deposits-chemical evidence for a genetic connection between petrogenesis and mineralization”, Mineralogical Association of Canada, Short Course Series 23 (1995) 401-418.

[33] Meinert L. D., “Application of skarn deposit zonation to mineral exploration and Mining Geology”, Exploration and Mining Geology 6 (1997) 185-208.

[34] Newberry R. J., Swanson S. E., “Scheelite skarn granitoids: an evalution of the role of magmatic source and process”, Ore Geology Reviews 1 (1986) 57-81.

[35] Oztûrk Y. Y., Helvaci C., Satir M.,“Genetic relations between skarn mineralization and petrogenesis of the Evciler Granitoid, Kazdag, Canakkale, Turkey and comparison with world skarn granitoids”, Turkish Journal of Earth Sciences 14 (2005) 2155-280.

[36] حسنی پاک ع.ا.، "اصول اکتشافات ژئوشیمیایی"، انتشارات دانشگاه تهران (1381) 615 ص.

[37] حسامی ع.، "پروژه نیمه تفصیلی اکتشاف تنگستن"، سازمان زمین‌شناسی و اکتشافات معدنی کشور (1382) 132ص.