Petrogenesis of skarn related Cu-porphyry intrusion deposit, Ali-Abad- Darreh Zereshk, Yazd

Document Type : Research Article

Authors

1 Shiraz

2 Isfahan

Abstract

The study area is a part of Cenozoic magmatic belt of Central Iran, which is located in the West of Yazd porovince. Contact metamorphism and skarn occurred in conglomerate part of Sngestan Formation. The Oligocene intrusion bodies of Ali-Abad-Darreh Zereshk are leucocerate and have the chemical composition of granite to granodiorite with calc-alkaline affinity from volcanic arc geological setting. The main mineral assemblage of skarn in order of imprtance is as follow: Garnet + epidote + quartz + calcite + pyrite + iron oxides. Brown garnets are the skarn characteristic mineral. EPMA analysis has shown that the chemical composition with garnet belong to andradite-grossular solid-solution (And 65, Gross 30) with more andradite component. The high permeability and presence of carbonate pebbles in conglomerate are two important factors for fluid flow and genesis of garnets. Distinct oscillatory zoning in garnets is resulted from the change of fO2 in fluids. The evolution of Ali-Abad skarn is took place in the range of 380 to 530 ºC, 0.5 Kbar pressure and high fO2. Also close association of this skarn with Ali-Abad intrusive with Cu-porphyry mineralization shows that this skarn is a Cu-porphyry type skarn.

Keywords


[1] مکی زاده م. ع. بررسی کانی شناسی و پترولوژیکی اسکارن های ایران مرکزی (استان یزد)، دانشگاه شهید بهشتی، (1387) 188 صفحه.
[2] Yücel-Öztürk Y., Helvaci C., and Satir M., Genetic relations between skarn mineralization and petrogenesis of the Evciler granitoid (Kazdag,
Çanakkale - Turkey) and comparison with world skarn granitoids: Turkish Journal of Earth Sciences, 14 (2005) 255-280.
[3] نبوی م. ح.، نقشه چهارگوش یزد، مقیاس 000/1:250 سازمان زمین شناسی کشور (1972).
[4] Forster, H., Mesozoic-Cenozoic metallogenesis in Iran, Journal of the Geological society of London, 135 (1978) 443-445.
[5] سبزه‌ئی م.، علایی مهابادی، س.، گزارش مقدماتی مطالعات زمین شناختی و سنگ شناختی مرمرها و اسکارنهای منطقه ده بالا، یزد، مدیریت زمین شناسی منطقه جنوب خاوری مرکز کرمان، منتشر نشده، (1365)35 ص.
[6] Zarasvand A. Liaghat s. and Zentill M., Geology of the Darreh-Zereshk and Ali-Abad porphyry copper deposits, Central Iran, International Geology Review, 47 (2005) 620-646.
[7] رضائیان ک.، نقره ئیان م.، مکی زاده م. ع. و شرافت ش.، زمین شناسی و ژنز اندیس کانی فیروزه، علی آباد (تفت یزد)، مجله پژوهشی دانشگاه اصفهان (علوم پایه) جلد هیجدهم، شماره 2،(1382) صص 145-158.
[8] اسلامی زاده ع.، پترولوژی سنگهای آذرین علی آباد و دره زرشک ناحیه یزد (زون ایران مرکزی) و کانه‌زائی مس وابسته به آن، پایان‌نامه دکتری، دانشگاه آزاد اسلامی ایران، واحد علوم و تحقیقات، (1382) 231 صفحه.
[9] Chappell B. W., and white, A. J. R., Two contrasting granite types: Pacific geology, (1974) 8, 173-174.
[10] White A. J. R. and Capplle, B. W, Ultrametamorphism and granitic genesies: Tectonophysics (1974) 43, 7-22.
[11] Middlemost E.A.K., Magmas and Magmatic rocks Longman Group Limited ,Essex (1985).
[12] Irvine T. N., Baragar W. R. A., A guide to the chemical classification of the common volcanic rocks, Can. J. Earth Sci., 8 (1971) 523-548.
[13] Maniar P. D. and piccolo P. M., Tectonic discrimination of granitoids ,Geilogical society of America Bulltin, 101 (1989) 635-643.
[14] Pearce J. A., Harris N. and Tindle A. G., Trace element discrimination diagrams for tectonic interprtation of granitic rocks. Jour. Petrol., 25, 4, (1984) 956-983.
[15] Murad E., Zoned birefringent garnets from Thera Island, Santorini Group (Aegean Sea), Min., 40, (1975) 715-719.
[16] Jamtveit B., Wogelius R. A. and Fraser D. G., Zonation patterns of skarn garnets, records of hydrothermal system evolution, Geo., 21, (1993) 113-116.
[17] Yardley B.W.D., Rochelle, C. A., Barnicoat, A. C., and Lioyd, G. E., Oscillatory zoning in metamorphic minerals, Anindicator of infiltration metasomatism, Miner. Mag., 55, (1991) 357-365.
[18] Clechenko C. C. and Valley J. W., Oscillatory Zoning in garnet from the Willsboro wollastonite Skarn, Adirondack Mts, New York: a record of shallow hydrothermal processes preserved in a granulite facies terrane, J. Metam. Geol., 21, (2003) 771-784.
[19] مسعودی ف.، مهرابی ب. و فرازدل ف.، نوع ساختمان منطقه‌ای گارنت در اسکارنهای توده نفوذی قهرود، جنوب کاشان، مجله بلورشناسی و کانی شناسی ایران، سال سیزدهم شماره 1، (1384) صص43 تا 60.
[20] Engi M.Wersin P., Derivation and application of a solution Model for calcic garnet ,schweizerische Mineralogische and petrographische Mitteilungen 67, (1987)53-73.
[21] Huckenholz H.G., Fehr ,K.T., Stability relationships of grossular + guartz + wollasttonite + anorthite II, The erect of grandite- hydrograndite solid solution, Neues Jahrbuch fur Mineralogie abhand lungen 145. (1982).1-33
[22] Meinert l. D., Skarns and skarn deposits, Geoscience Canada, v. 19, (1992) 145-162.
[23] Tracy R. J., Frost B. R., Phase equilibria and thermobarometery of calcareous, ultramafic and mafic rocks, and iron formation, In D. M., Kerrick, E. d., Contact Metamorphism, Min. Soc. Amer., Reviews in Mineralogy, 26, (1991) 207-289.
[24] Deer W.A. Howie R.A and zussman J., An introduction to the rock forming minerals , seventeenth impression, Longman , (1991) 528p.
[25] Miyashiro A., Metamorphism and metamorphic belts, George Allen and Uniwin, London, (1973) 495 p.
[26] Einaudi M. T., Meinert L. D. and Newberry R. J., Skarn deposits. In Econ. Geol. 75th Anniv. Econ. Geo. Publ. Co, (ed. B. J. Skinner), (1981) 317-391.
[27] Robb L. 2005, Introduction to ore-forming processes, Blackwell publishing. (2005) 373.
[28] ژیلبرت جان، م، زمین شناسی کانسارها، ترجمه سعید علیرضائی، نشر دانش امروز، (1385) 1155 صفحه.
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