بررسی زمین شیمی عناصر اصلی و جزئی در نهشته منگنز قزل داش داغی، شمال‌ غرب مرند (آذربایجان شرقی)

نهشته منگنز قزل داش داغی در 25 کیلومتری شمال غرب شهر مرند در استان آذربایجان شرقی قرار دارد. از نظر ساختاری، این نهشته در پهنه مرکزی واقع‌شده است. میزبان کانی زایی در افق i توفیت و سنگ‌ آهک آب شیرین و در افق ii کنلگومرا و ماسه سنگ حوضه آتشفشانی کواترنری است. شکل کانی زایی در افق i، لایه ایلامینه ای و در افق ii، عدسی‌پرشدگی شکستگی هاست. ویژگی‌های زمین شیمیایی نهشته توسط مقدار عناصر اکسیدهای اصلی، جزئی مطالعه و منشا کانی زایی بحث‌ شده است. غلظت های به نسبت بالای al (0.01 تا 7.39 درصد وزنی، متوسط = 1.34) احتمالاً به‌خاطر لیتیک توف های میزبان است. مقادیر کم تیتانیوم (0 تا 0.28 درصد وزنی، متوسط = 0.05) نشانه ورود اندک مواد آواری طی کانی زایی است. داده هایی مثل mn:fe (متوسط 21.29)، ba بالا (متوسط 1782.4)،co:ni (متوسط 0.79)، co:zn (متوسط 1.18) و نمودارهای تمایز نهشته های منگنز نشان می دهد که نهشته قزل داش داغی کانی زایی آتشفشانی رسوبی از نوع گرمابی است.

The Study of Major and Trace Elements Geochemistry of Gezeldash Daghi Mn Deposit, NW of Marand (Eastern Azerbaijan)

Introduction;It is generally understood that manganese deposits have a diverse origin, based on their mineralogy, chemical composition and tectonic setting. Marine Mnbearing deposits are classified as hydrogenous, hydrothermal and also biogeneticbacterial deposits (Bonatti et al., 1972; Hein et al., 1997; Bau et al., 2014; Polgári et al., 2012; Schmidt et al., 2014). Hydrogenous processes can form ferromanganese crusts, which result from slow precipitation of seawater at the seafloor often via microbial mediation (Toth, 1980; Dymond et al., 1984; Bau and Dulski, 1999; Usui and Someya, 1997; Hein et al., 2000; Jach and Dudek, 2005). Diagenetic manganese deposits occur as nodules and precipitate from hydrothermal solutions or pore water (Polgári et al., 1991; Oksuz, 2011; Polgári et al., 2012), whereas hydrothermal ore deposits are stratabound or occur as irregular bodies and epithermal veins, where they are formed in a marine environment near spreading centers, intraplate seamounts or in subductionrelated island arc setting (Roy, 1992; Roy, 1997; Hein et al., 2008; Edwards et al., 2011).; ;Materials and Method;Eighteen Ore samples (~ 500 g each) were collected systematically from the Gezeldash Daghi manganese deposit. All these ore samples were taken representatively from the surface outcrops ore beds in different places for geochemical analyses. Ore samples were powdered under 200 meshes and analyzed at Iran mineral processing research center laboratories, Tehran. After being prepared by the Lithium Borate Fusion method, their major oxide and trace element contents were determined with ICPOES. The results of the analyses are given in Tables 1 and 2.; ;Results and Discussion;The deposit is hosted in various lithology and horizons consisting of: 1) tuffite interlayered with limestone, 2) conglomerate and sandstone lithology into volcanosedimentary basin located at 25 km northwest of Marand city (N38°35ʹ40ʺ, E45°42ʹ40ʺ). Major and trace element assessments show that hydrothermal solutions were effective in the formation of the Gezeldash Daghi manganese deposit. Also, field observations reveal that manganese mineralization occurred as laminatedlayered and fracturefilling form in limestone and tuffite at horizon I and the spacefilling form between conglomerate clasts and veinlet form in sandstone at horizon II with quaternary age. Therefore, it can be concluded that hydrothermal solutions were caused in the formation of the manganese deposit which may be described as related to volcanohydrothermal occurrence.; ;Acknowledgements;The authors are grateful to the Tabriz University Grant Committee for research funding.;References ;Bau, M. and Dulski, P., 1999. Comparing yttrium and rare earths in hydrothermal fluids from the MidAtlantic Ridge: implications for Y and REE behavior during nearvent mixing and for the Y/Ho ratio of Proterozoic seawater. Chemical Geology, 155(1–2): 77–90.;Bau, M., Schmidt, K., Koschinsky, A., Hein, J.R. and Usui, A., 2014. Discriminating between different genetic types of marine ferromanganese crusts and nodules based on rare earth elements and yttrium. Chemical Geolgy, 381: 1–9.;Bonatti, E., Kraemer, T. and Rydell, H., 1972. Classification and genesis of submarine ironmanganese deposits. In: D. Horn (Editor), Ferromanganese Deposits on the Ocean Floor. National Science Foundation, Washington, pp. 149–166.;Dymond, J., Lyle, M., Finney, B., Piper, D.Z., Murphy, K., Conard, R. and Pisias, N., 1984. Ferromanganese nodules from MANOP sites H, S and R–control of mineralogical and chemical composition by multiple accretionary processes. Geochimica et Cosmochimica Acta, 48(5): 931–949.;Edwards, K.J., Glazer, B.T., Rouxel, O.J., Bach, W., Emerson, D., Davis, R.E., Toner, B.M., Chan, C.S., Tebo, B.M., Staudigel, H. and Moyer, C.L., 2011. Ultradiffuse hydrothermal venting supports Feoxidizing bacteria and massive umber deposition at 5000 m off Hawaii. The ISME Journal, 5(11): 1748–1758.;Hein, J.R., Koschinsky, A., Bau, M., Manheim, F.T., Kang, J. K. and Roberts, L., 2000. Cobaltrich ferromanganese crusts in the Pacific. In: D.S. Cronan, (Editor), Handbook of Marine Minerals Deposit. CRC Press, Boca Raton, Florida, pp. 239–279.;Hein, J.R., Koschinsky, A., Halbach, P., Manheim, F.T., Bau, M., Kang, J. K. and Lubick, N., 1997. Iron and manganese oxide mineralization in the Pacific. In: K. Nicholson, J.R. Hein, B. Buhn, S. Desgupta, (Editors), Manganese Mineralization: Geochemistry and Mineralogy of Terrestrial and Marine Deposits. Geological Society Special Publication, London, pp. 123–138.;Hein, J.R., Schulz, M.S., Dunham, R.E., Stern, R.J. and Bloomer, S.H., 2008. Diffuse flow hydrothermal manganese mineralization along the active Mariana and Southern IzuBonin arc system, western Pacific. Journal of Geophysical Research, 113(8): 1–29.;Jach, R. and Dudek, T., 2005. Origin of a Toarcian manganese carbonate/silicate deposit from the Krížna unit, Tatra Mountains, Poland. Chemical Geology, 224(1–3): 136–152.;Oksuz, N., 2011. Geochemical characteristics of the Eymir (SorgunYozgat) manganese deposit, Turkey. Journal of Rare Earths, 29(3): 287–296.;Polgári, M., Hein, J.R., Vigh, T., SzabóDrubina, M., Fórizs, I., Bíró, L., Müller, A. and Tóth, A.L., 2012. Microbial processes and the origin of the Úrkút manganese deposit, Hungary. Ore Geology Reviews, 47: 87–109.;Polgári, M., Okita, P.M. and Hein, J.R., 1991. Stable isotope evidence for the origin of the Úrkút manganese ore deposit, Hungary. Journal of Sedimentary Research, 61(3): 384–393.;Roy, S., 1992. Environment and processes of manganese deposition. Economic Geology, 87(5): 1218–1236.;Roy, S., 1997. Genetic diversity of manganese deposition in the terrestrial geological record. In: K. Nicholson, J.R. Hein, B. Buhn and S. Dasgupta (Editors), Manganese Mineralization: Geochemistry and Mineralogy of Terrestrial and Marine Deposits. Geological Society, special publication, London, pp. 5–27.;Schmidt, K., Bau, M., Hein, J. and Koschinsky, A., 2014. Fractionation of the geochemical twins ZrHf and NbTa during scavenging from seawater by hydrogenetic ferromanganese crusts. Geochimica et Cosmochimica Acta, 140: 468–487.;Toth, J.R., 1980. Deposition of submarine crusts rich in manganese and iron. GSA Bulletin, 9(1): 44–54.;Usui, A. and Someya, M., 1997. Distribution and composition of marine hydrogenetic and hydrothermal manganese deposits in the northwest Pacific. In: K. Nicholson, J.R. Hein, B. Buhn and S. Dasgupta (Editors), Manganese Mineralization: Geochemistry and Mineralogy of Terrestrial and Marine Deposits. Geological Society, Special Publications, London, pp. 177–198.