Mineral chemistry and temperature condition investigations of the Sarvian Iron ore deposit (Markazi province, Delijan city).

Abstract

The Sarvian magnetitic skarn deposit has been formed due to the granodiorite injection into the oligomiocene limestones. It is a calcic skarn deposit with dominated exoskarn section. Garnet and pyroxene are two coupled indicator minerals that have been formed by Mg-Si-Fe-bearing fluid remained from magma crystallization. These minerals are observed extensively in the metasomatic haloes in the country rocks and could be used to determine the conditions of temperature and pressure that have been governed on skarnization. It is revealed from microprobe analysis that the garnets in the Sarvian deposit are of the grossular-andradite type that are enriched in Fe & Ca, and depleted in Mg & Mn. These garnets show a sharp zoning structure. The distributions of MnO, CaO, Al2O3 and FeO in the zoned garnets indicate that from the core to rim, their composition changes gradually from grossular to andradite. The composition of the garnets and pyroxenes in the Sarvian ore deposit is compatible with the Fe-skarn deposits. Pyroxenes in the Sarvian ore deposit are of Ca-riched diopsid-hedenbergite type. During the prograde stage in which the anhydrous minerals such as garnets and pyroxenes were formed, the temperatures are comparable with albite-epidote and hornblende-hornfelse facieses. According to the temperatures of the garnet-clinopyroxene minerals formation, the temperatures of prograde stage have been determined between 370-500 °C. On the other hand, the results of fluid inclusion studies on quartz grains obtained from mineralized veins suggest that the temperatures during the iron mineralization in the retrograde stage of skarnization have been 400-380 ° C.

Keywords


[1] Einaudi M.T., Meinert L. D., Newberry R. J., "Skarn deposit", Economic Geology, 75th Anniv (1981) 317-391.

[2] Pirajno F., "Hydrothermal Mineral Deposits", Speringer-Verlag)1992 (709.

[3] Lindsley D. H., "Pyroxene thermometry", American Mineralogist68 (1983) 477-493.

]4[ قلمقاش ج.، باباخانی ع.ر.، " نقشه زمین‌شناسی 1:100000 کهک"، سازمان زمین شناسی و اکتشافات معدنی کشور.)1379(

]5 [بارانی ن.، زمانیان ح.، زارعی ر.، پازوکی ا.، "زمین شناسی اقتصادی کانسار آهن سرویان،دلیجان (استان مرکزی)"، پایان نامه کارشناسی ارشد دانشگاه لرستان (1392).

[6] سجادی ف.، "مطالعه پترولوژی، فسیل شناسی و چینه شناسی محدوده بین نطنز و اردستان (ایران مرکزی)"، پایان نامه فوق لیسانس دانشگاه تهران(1371).

[7] Whitney D.L., Evans B.W., "Abbreviations for names of rock-forming minerals", American Mineralogist 95) 2010 (185-187.

[8] Meinert L. D., "Skarns and skarn deposits", Geoscience Canada 19 (1992) 145-162.

[9] Meinert L.D., "Skarn zonation and fluid evalution in the Groundhog Mine, Central Mining District, New Mexico", Economic Geology 82 (1989) 523-545.

[10] مسعودی ف.، مهرابی ب.، فرازدل ف.،" نوع ساختمان منطقه ای گارنت در اسکارن های توده نفوذی قهرود، جنوب کاشان"، مجله بلور شناسی و کانی شناسی ایران، سال سیزدهم، شماره 1، بهار و تابستان1384، ص60-43.





[11] Yang P., Pattison D., "Genesis of monazite and Y zoning in garnet from Black Hills, South Dakota", Journal of Lithos 88 (2009) 233-253.

[12] Jamtviet B., "Oscillatory Zonation Patterns in hydrothermal grossular-andradite garnet, Nonlinear behavior in regions of immiscibility", American Mineralogist 76 )1991 (319- 1327.

[13] Amthauer G, Rossman G. R., "The hydrous component in andradite garnet", American Mineralogist 83 )1998 (835- 840.

[14] Morimoto N., Kitamura M., "Q-J diagram for classification of pyroxenes", Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists (in Japanese) 78 (1983( 141.

[15] Deer W.A., Howie R.A., Zussman J., "An introduction to the rock forming minerals: Second edition", Longman Scientific and Technical (1992). 696.

[16] Nash J.T., Theodor A., "Fluid inclusion petrology-data from porphyry copper deposits and applications to exploration; United States Geological Survey professional 107(1971) 907-923.

[17] Roedder E., "Fluid inclusions", Reviews in Mineralogy, Mineralogical Society of America 12 (1984) 644.

[18] Hass J.I., "The effect of salinity on the maximum thermal gradient of a hydrothermal system at hydrostatic pressure", Economic Geology 54 (1971) 940-946.

[19] Kendy G.C., "Pneumatolysis and the liquid inclusion method of geologic thermometry", Economic Geology 45 (1950) 533-547.

[20] Wilkinson J.J., "Fluid inclusions in hydrothermal ore deposits", Lithos 25 (2001) 229- 279.

[21] Davidson GJ, Davis BK., "Some controls on oxidation state variation of oxide Cu–Au systems", Mineralogical Society of America 33 (2007) 358-372.

]22 [ترابی ق.، نوربهشت ا.، شیردشت‌زاده ن.، پیرنیات.، "زمین دماسنجی اسکارن موجود در افیولیت ملانژ نایین(استان اصفهان)"، مجله بلور و کانی شناسی ایران شماره 2 (1386) صفحه 375-383.

]23 [شیخی ف.، اعلمی نیا ز.، طباخ شعبانی ا، ع.، "زمین دماسنجی اسکارن سر انجیرک (جنوب غرب قروه استان کردستان)"، مجله بلور و کانی شناسی ایران(1391) شماره 20 صفحه 343-354

]24[ ساکی ع.، پورکاسب ه.، "مطالعه شرایط فیزیک و شیمیایی تشکیل اسکارن ها در همبری باتولیت الوند با سنگ های آهکی دگرگون شده، همدان، غرب ایران"، مجله زمین شناسی اقتصادی (1391) شماره 1، صفحه 123 تا 134.

[25] Krogh E. J., "The garnet-clinopyroxene Fe-Mg geothermometer-a reinterpretation of existing experimental data", Contributions to Mineralogyand Petrology 99 (1988) 44-48.

[26] Krogh E. J., "The garnet-clinopyroxene Fe+2-Mg geothermometer & an updated calibration", Journal of Metamorphic Geology 18 (2000) 211-219.

[27] Ellis D. J., Green D. H., "An experimental study of the effect of Ca upon the garnet-clinopyroxene Fe-Mg exchange equilibria", Contributions to Mineralogy and Petrology 71 (1979) 13 -22.

[28] Powell R., "Regression diagnostics and robust regressionin geothermometer/geobarometer calibration: the garnet clinopyroxenegeothermometer revisited", Journal of Metamorphic Geology 2 (1985) 33-42.

[29] Raheim A., Green D. H., "Experimental determination of the temperature and pressure dependence of the Fe-Mg partition coefficient for coexisting garnet and clinopyroxene", Contributions to Mineralogy and Petrology 48 (1974) 179–203.

[30] Nakamura D., Hirajima T., "Exprimental evaluation of garnetclinopyroxene geothermometery as applied to eclogites", Contributions to Mineralogy and Petrology 150 (2005) 581-588.

[31]Li Li H, Kuang X, Mao A, Li Y, Wang S., "Study of local structures and optical spectra for octahedralFe3 + centers in a series of garnet crystals A3B-2C3O12 (A = Cd, Ca; B = Al, Ga, Sc, In; C = Ge, Si) ", Journal of Chemical Physics Letters 484 (2010) 387–391.

[32] Winkler H., "Petrogenesis of Metamorphic Rocks", New York: Springer (1976).

[33] Sokolov G.A., Grigor'ev V.M., "Deposits of iron, in Smirnov, V.I., ed., Ore deposits of the U.S.S.R", London, Pittman1 (1977) 7-113.

[34] Rose A. W., Burt D. M., "Hydrothermal alteration In H. L. Barnes, Ed.", Geochemistry of Hydrothermal ore Deposits, John wiley and sons 17 (1979) 173-235.

[35] Einaudi and Burt., "introduction, Terminology- classification and composition of skarn deposite", Economic Geology 77 (1982) 445-455.

[36] Zharikov V.A., "Skarns: Part I., II and III, Int’l", Geology Review 12 (1970) 760 -775.