زمین شیمی عناصر نادر خاکی در کانسارهای فلوریت سازند الیکا، شرق استان مازندران

نوع مقاله : علمی- پژوهشی

نویسندگان

گلستان

چکیده

مطالعه زمین شیمی عناصر نادر خاکی در کانسارهای فلوریت سازند الیکا (تریاس میانی)، محتوای پایین عناصر مذکور را در فلوریت ها (REEs 0/5-18 ppm=∑)، کلسیت ها (REEs 0/5-3 ppm=∑) و سنگهای کربناته میزبان (آهک: REEs 1/8-7 ppm=∑، آهک دولومیتی: REEs 6/5 ppm=∑) نسبت به بازالت ها (REEs 43 ppm=∑) و شیل های تریاس بالایی (REEs 261 ppm=∑) آشکار کرد. تهی شدگی فلوریت ها از عناصر سبک (10-La/Sm=2) و غنی شدگی نسبی آنها از عناصر سنگین (0/08-La/Yb=0/01) در مقایسه با سنگ میزبانهای آهکی (4-La/Yb=0/1-1/5 ، La/Sm=2/5 ) و آهک دولومیتی (La/Yb=0/07-0/4 ، La/Sm=4/28 ) همراه با بی هنجاری مثبت Eu در فلوریت ها، تشکیل کانسارهای فلوریت مورد بررسی را 1- بعد از رسوب‌گذاری و سنگ شدگی سنگهای کربناته میزبان و 2- توسط محلولهای گرمابی رسوبی زاد واجد شرایط احیایی و دامنه دمایی 200-250 درجه سانتی‌گراد شبیه کانسارهای نوع دره می‌سی سی پی غنی از فلوریت مانند ایلینویز-کنتاکی (امریکا) و پناین (انگلستان) معرفی کرد. پژوهش حاضر نشان داد، محتوای پایین مجموع غلظت عناصر نادر خاکی در فلوریت های ته نشست یافته از این محلولها می توانسته ناشی از 1- افزایش pH محلول گرمابی کانه ساز طی برهم‌کنش با سنگ میزبان کربناته؛ 2- کاهش تدریجی غلظت فعال فلوئور در محلول گرمابی ناشی از کانی سازی نسلهای مختلف فلوریت و 3- محتوای پایین عناصر نادر خاکی سنگهای کربناته میزبان بوده باشد.

کلیدواژه‌ها


Aghanabati, S.A., 2005. Geology of Iran. Geological Survey of Iran Publication, Tehran, 586 pp (in Persian).
Alirezaee, S., 1989. Contribution to stratigraphy and mode of generation of F-Pb-Ba deposits in Triassic of eastern Alborz. M.Sc. Thesis, Tehran University, Tehran, Iran, 87 pp (in Persian).
Bau, M., Romer, R.L., Luders, V. and Dulski, P., 2003. Tracing element sources of hydrothermal mineral deposits: REE and Y distribution and Sr-Nd-Pb isotopes in fluorite from MVT deposits in the Pennine Orefield, England. Mineralium Deposita, 38(8): 992–1008.
Bonsall, T.A., Spry, P.G., Voudouris, P.C.H., Tombros, S., Seymour, K.St.‌ and Melfos, V., 2011. The Geochemistry of Carbonate-Replacement Pb-Zn-Ag Mineralization in the Lavrion District, Attica, Greece: Fluid Inclusion, Stable Isotope and Rare Earth Element Studies. Economic Geology, 106(5): 619–651.
Brunet, M.F., Granath, J.W.‌ and Wilsmen, M., 2009. South Caspian to Central Iran Basins. The Geological Society London Special Publications, 312(2): 1-6.
Chesley, J.T., Halliday, A.N., Kyser, T.K. and Spry, P.G., 1994. Direct Dating of MississipValley-type mineralization: Use of Sm-Nd in fluorite. Economic Geology, 89(9):1192-1199.
Constantopoulos, J., 1988. Fluid inclusion and REE geochemistry of fluorite from south-central Idaho. Economic Geology, 83(5): 626–636.
Dill, H. G. Hansen, B.T.‌ and Weber, B., 2011. REE contents, REE minerals and Sm/Nd isotopes of granite-and unconformity-related Fluorite mineralization at the western edge of the Bohemian Massif: With special reference to the Nabburg-Wölsendorf District, SE Germany. Ore Geology Reviews, 40(1): 132–148.
Ehya, F., 2012. Variation of mineralizing fluids and fractionation of REE during the emplacement of the vein-type fluorite deposit at Bozijan, Markazi Province, Iran. Journal of Geochemical Exploration, 112(1): 93–106.
Ekambaram,‌V., Brookins, D.G., Rosenberg, P.E.‌‌ and Emanuel, K.M., 1986. Rare earth element geochemistry of fluorite-carbonate deposits in western Montana, U.S.A. Chemical Geology, 54(2): 319-331.
Eppinger, R.G, and Closs L.G., 1990. Variation of trace elements and rare earth elements in fluorite, a possible tool for exploration. Economic Geology, 85(10): 1896–1907.
Fisher, J., Lillie, R.‌ and Rakovan, J., 2013. Flourite in Mississippi Valley-Type Deposits. Rocks and Minerals, 88(1): 20-47.
Gorjizad, H., 1996. Study on geology, mineralogy, facies analysis and genesis of Pachi Miana fluorite deposit. M.Sc. Thesis, Tarbiat Modaress University, Tehran, Iran, 156 pp.
Henderson, P., 1984. Rare earth element geochemistry, Developments in Geochemistry. Elsevier Science Publishers, Amsterdam, 2510 pp.
Hill, G.T., Campbell, A.R., and Kyle, P.R., 2000. Geochemistry of southwestern New Mexico fluorite occurrences: implications for precious metals exploration in fluorite-bearing systems. Journal of Geochemical Exploration, 68(1): 1–20.
Joseph, L.‌ and Graf, Jr., 1984. Effects of Mississippi Valley-Type Mineralization on REE Patterns of Carbonate Rocks and Minerals, Viburnum Trend, Southeast Missouri. The Journal of Geology, 92(3): 307-324.
Moller, P., Bau, M., Dulski, P.‌ and Lüders, V.,1998. REE and Y Fractionation in Fluorite and Their Bearing on Fluorite Formation. Proceedings of the Ninth Quadrennial IAGOD Symposium, Schweizerbart, Stuttgart.
Moller, P., Parekh, P.P. and Schneider, H.J., 1976. The application of Tb/Ca–Tb/La abundance ratios to problems of fluorspar genesis. Mineralium Deposita, 11(1): 111– 116.
Palmer, D.A. S and Williams-Jones, A.E., 1996. Genesis of the carbonatite hosted fluorite deposit at Amba Dongar, India: Evidence from fluid inclusions, stable isotopes and whole rock-mineral geochemistry. Economic Geology, 91(8): 934–950.
Rollinson, H., 1993. Using geochemical data: evaluation, presentation, interpretation. Longman Publisher, UK, 352 pp.
Ronchi, L.H., Touray, J.C., Michard, A.‌ and Dardenne, M.A., 1993. The Riberia fluorite district, Southern Brazil. Geological and geochemical (REE, Sm–Nd isotopes) characteristics. Mineralium Deposita, 28(1): 40–52.
Sanchez, V., Cardellach, E., Corbella, M., Vindel, E., Crespo, T.M.‌ and Boyce, A.J., 2010. Variability in fluid sources in the fluorite deposits from Asturias (N Spain): Further evidences from REE, radiogenic (Sr, Srn, Nd) and stable (S, C, O) isotope data. Ore Geology Reviews, 37(1): 87–100.
Sasmaz, A., Yavuz, F., Sagiroglu, A.‌ and Akgul, B., 2005. Geochemical patterns of the Akdagmadeni (Yozgat, Central Turkey) fluorite deposits and implications. Journal of Asian Earth Sciences, 24 (3): 469–479.
Schönenberger, J., Köhler, J.‌ and Markl, G., 2008. REE systematics of fluorides, calcite and siderite in peralkaline plutonic rocks from the Gardar Province, South Greenland. Chemical Geology, 247(1): 16–35.
Schwinn, G. and Markl, G., 2005. REE systematics in hydrothermal fluorite. Chemical Geology, 216(2): 225– 248.
Shariatmadar, A., 1999. Geology and genesis of Sheshrodbar fluorite deposit. M.Sc. Thesis, Tarbiat Modaress University, Tehran, Iran, 230 pp (in Persian).
Souissi, F., Souissi, R.‌ and Dandurand, J.L., 2010. The Mississippi Valley-type fluorite ore at Jebel Stah (Zaghouan district, north-easternTunisia): Contribution of REE and Sr isotope geochemistry to the genetic model. Ore Geology Reviews, 37(1):15–30.
Sverjensky, D.A., 1989. The diverse origins of Mississippi Valley-type Zn–Pb–Ba–F deposits. Chronicle of mineral research and exploration, 495(1): 5 – 13.
Tabasi, H., 1997. Structural analysis of Sheshrodbar fluorite mine. M.Sc. Thesis, Tarbiat Modaress University, Tehran, Iran, 130 pp (in Persian).
Vahabzadeh, G., 2008. Comparison between mineralogy, geochemistry and genesis of fluorite deposits of Savad Kuh region. Ph.D. Thesis, Shahid Beheshti University, Tehran, Iran, 174 pp (in Persian).
Vahabzadeh, G., Khakzad, A., Rasa, I.‌ and Mosavi, M.R., 2008. Oxygen and Carbon Isotopes and REE Study in the Emaft Fluorite Mine, Savad Kuh Region (Mazandaran province). Research Journal of Isfahan University, 29(3): 189-200 (in Persian).
Vahabzadeh, G., Khakzad, A., Rasa, I.‌ and Mosavi, M.R., 2009. Study on S isotopes in galena and barite of Savad Kuh fluorite deposits. Journal of Basic Science, Islamic Azad University, 69(18): 99-108 (in Persian).
Williams-Jones, A.E., Samson, I.M.‌ and Olivo, G.R., 2000. The genesis of hydrothermal fluorite-REE deposits in the Gallinas Mountains, New Mexico. Economic Geology, 95(2):327–342.
CAPTCHA Image