Geochemistry and genesis of Robat-Paein barite deposit, Khomein, Markazi province

Abstract

The Robat-Paein barite deposit is located about 30 Km northwest of Khomein city, in the Sanandajـ Sirjan zone. The Lower Cretaceous carbonate sequences are the host rock of barite mineralization in the Robat-Paein­ deposit.­­ These carbonate sequences consist mainly of massive bedded orbitolina-bearing limestone (undergone dolomitization in some areas) as well as marl, shale and thinly bedded limestone. ­In this region, epigenetic mineralization occurred as vein, open space filling, fracture filling, massive and replacement textures in carbonate host rocks. The low ratios of Al2O3 (0.1-0.12 wt%), TiO2 (0.01-0.3 wt%), and a relatively high Sr concentration (average 3180 ppm) in the samples of Robat-Paein­ barite deposit could be a sign for presence of ­low temperature­ hydrothermal­ ore-bearing fluids. The enrichment of ­LREE/HREE indicate that­ chlorine-rich fluids were­ dominant during mineralization,­ compared to that­­ of ­fluorinated fluids.­­ According to transportation, LREE hydrothermal solution is made by complex chloride, because they are more soluble chlorides and can be deposited in the final stages.­­­­ The REE patterns of­ the­­ Robat­-Paein barite is analogous to continental margin low temperature hydrothermal barites of California SCCB­. The negative Ce anomalies (Ce/Ce*­= 0.26-0.91), strong positive Eu anomalies (Eu/Eu* between 1.83-3.06), high Ce/La ratios (Ce/La­=1.05), low Y/Ho ratios (Y/Ho between 4-7.14) are the indicative of deposition in continental setting­.­ ­­Based on the field observation, as well as mineralogical and geochemical studies, it seems that the Robat-­Paein deposit could be classified as a MVT deposit.

Keywords


[1] خوش جو ا.، "کانسارهای باریت ایران، نشریه سازمان زمین‌شناسی و اکتشافات معدنی کشور" (1378).

[2] آدابی م.، جمالیان م.، " شناسایی ترکیب کانی‌شناسی اولیه و نحوه کانسار‌سازی در کربنات‌های معدن رباط (خمین ‌ـ اراک)"، مجله‌ی علوم زمین، شماره 66 (1385) 2-23.

[3]‌ McDonough W.F., Sun S.S., "The composition of the earth", Chemical Geology 120(3-4) (1995) 223–253.

[4] Zarasvandi A., Charchi A., Carranza‌ E.‌J.‌M., "Alizadeh. B., 2008. Karst bauxite deposit in the Zagros mountain belt, Iran", Ore Geology Reviews, 32, P. 521-532.

[5] واعظی پور م.، خلقی م.، " نقشه زمین‌شناسی 1:100000ورچه‌، سازمان زمین‌شناسی کشور" (1384).

[6] پیرنجم الدین، ح.، راستاد، ا.، محمودی، پ.، 1393، "جایگاه چینه‌ای افق‌های کانه زایی روی سرب و باریت در توالی کربناته کرتاسه زیرین منطقه معدنی رباط، حوضه جنوب اراک، پهنه سنندج سیرجان"، سی و سومین گردهمایی علوم زمین.

[7] Brand V., Veizer J., "‌Chemical diagenesis of multicomponent CarboNate system:Trace elements", Jour, Sed. Petrology, 50 (1980) 1219-1236.

[8] Pingitore N.E., "The behavior of Zn2+ and Mn2+ during CarboNate diagenesis: Theory and application", Jour. Sed. Petrology, 48 (1978) 799-814.

‌[9] Choi‌ Jai Ho, Hariya Yu., "Geochemistry and depositional environment of Mn oxide deposits‌ in‌‌ the Tokoro Belt, northeastern Hokkaido, Japan", doi: 10.2113/gsecongeo.87.5.1265 Economic Geology August 1, 1992 vol. 87 no. 5 1265-1274.

[10] Kato Y., Nakamura, K., 2003, "Origin and global tectonic significance of early Archean cherts from the Marble Bar greenstone belt, Pilbara Craton, Western Australia": Precambrian Research 125(3ـ4), 191ـ243.

‌[11] Stamatakis M.G., Hein J.R., "Origin of barite in Tertiary marine sedimentary rocks from Lefkas Island", Greece: Economic Geology, v. 88, no. 1, p. (1993) 91–103.

[12] Jurković I., Garašić V., Hrvatović H., "Geochemical characteristics of barite occurrences in the ‌ Palaeozoic complex of South-eastern Bosnia and their relationship to the barite deposits of the Mid- Bosnian Schist Mountain", Geologia Croatia 63(2), (2010) 241ـ258.

[13] جزی م. ع.، شهاب پور ج.، "بررسی خصوصیات کانی‌شناسی، ساختی، بافتی و ژئوشیمیایی معدن سرب نخلک، اصفهان"، مجله زمین‌شناسی اقتصادی شماره‌ی 2: (1389) صفحه 131-151.

[14] Guichard F, Church TM, Treuil M, Jaffrezic H, " Rare earths in barites: distribution and effects on aqueous partitioning", Geochim Cosmochim Acta 49(1979) 983–997.

[15] Taylor R. P., Fryer B. J., "Rare earth element geochemistry as an aid to interpreting hydrothermal ore deposits". In: Mineralization associated with acid magmatism (ed) A M Evans (John Wiley & Sons, Ltd). (1983).

‌[16] Eppinger G. E., Closs L. G., "Variation of trace elements and rare earth elements in fluorite": A possible tool for exploration, Econ. Geol. 85, (1990) 1896ـ1907.

[17]‌ Murray R.W., "‌Chemical criteria to identify the depositional environment of chert: general principles and applications", Sedimentary Geology 90(3-4) (1994) 213– 232.

[18] ‌Evensen M.N., Hamilton P., O’Nions R.K., "Rare-earth abundances in chon-dritic meteorites", Geochim Cosmochim. Acta 42 (1978) 1199.

‌[19]‌ Ehya F., "Rare earth element and stable isotope (O, S) geochemistry of barite from the Bijgan deposit, Markazi Province, Iran". Mineralogy and Petrology 104(1-2) (2011) 81-93.

[20]‌ Elderfield H., "The oceanic chemistry of the rare earth elements", Philos Trans R Soc London A325:105–126.Ehya, F., 2011. Rare earth element and stable isotope (O, S) geochemistry of barite from the Bijgan deposit, Markazi Province, Iran. Mineralogy and Petrology 104(1-2) (1988) 81-93.

[21]‌ Bao SX., Zhou HY., Peng XT., Ji FW., Yao HQ., "Geochemistry of REE and yttrium in hydrothermal fluids from the Endeavour segment", Juan de Fuca Ridge. Geochem J 42(2008)359ـ370. [22] Hein J.R., ‌‌Zierenberg R.A., Maynard J.B., Hannington M.D., ‌‌"Barite-forming environments along a rifted continental margin, Southern California Borderland", Deep Sea Research part II: Tropical Studies in Oceanography 54(11-13) (2007) 1327-1349.

[23]‌ Bozkaya G, Gökce A., "Trace‌- ‌and rare-earth elements geochemistry of the Karalar (Gaipasa-Antalya) barite-galena deposits, Southern Turkey", Turk J Earth Sci 13(2004)63-75.

[24]‌ Griessmann M., Mumm A.S., Seifert T., Conor C., "The Mt. Mulga barite magnetite copper gold mineralisation, Olary Domain, South Australia", Journal of Geochemical Exploration 106 (2010) 110ـ 120.

[25]‌ Griffith E.M., Paytan A., "Barite in the Ocean‌-‌occurrence, geochemistry, and Palaeoceanographic applications", Sedimentology (doi: 10.1111/j.1365-3091.2012.01327) (2012