کاربرد شیمی‌ کانی کلینوپیروکسن در بررسی شرایط فیزیکی صعود ماگما، مطالعه موردی سنگ های آتشفشانی علی آباد، شمال غرب نایین

نوع مقاله : علمی- پژوهشی

نویسندگان

1 واحد اصفهان (خوراسگان)، دانشگاه آزاد اسلامی

2 دانشگاه اصفهان

چکیده

در منطقه علی­ آباد (شمال­ غرب نایین) سنگ­ های آتشفشانی با ترکیب آندزیت، تراکی­ آندزیت، داسیت و ریولیت به همراه سنگ­ های آذرآواری (توف) وجود دارند. از لحاظ کانی ­شناسی، این سنگ­ ها از فنوکریست­ های پلاژیوکلاز، کلینوپیروکسن، سانیدین، بیوتیت، کوارتز و کانی­ های اوپک در زمین ه­ای از میکرولیت­ های پلاژیوکلاز، شیشه و کانی­ های اوپک تشکیل شده­ اند. کلینوپیروکسن این سنگ­ ها از نوع اوژیت با ترکیب (En43-45, Wo 38-42, Fs 14-18) است. ترکیب شیمیایی کلینوپیروکسن نشان می ­دهد که این کانی در فشارهای کم تا متوسط تشکیل‌شده و بیانگر تبلور آنها در طی صعود ماگما و در عمق­ های مختلف است. توزیع Al و میزان Fe+3 در ساختار کلینوپیروکسن بیانگر تبلور آن از یک ماگمای آبدار با فشار بخار آب 10 درصد و با فوگاسیته بالای اکسیژن است. بر اساس محاسبات زمین دما-­فشارسنجی، کلینوپیروکسن­ ها در محدوده دمایی 1009 تا 1200 درجه سانتی­ گراد، محدوده فشار حدود 5/2 تا 7 کیلوبار و عمق 9 تا 18 کیلومتری متبلور شده ­اند.

کلیدواژه‌ها


Aghanabati, S. A., 1994. Geology of Iran. Geological Survey and Mineral Exploration of Iran, Tehran, 586 pp.
Amini, B. and Amini Chehragh, M.R., 2003. Geological map of Kajan, scale 1:100 000. Geological Survey of Iran, Tehran.
Aoki, K. and Shiba, I., 1973. Pyroxenes from lherzolite inclusions of Itinome-Gata, Japan. Lithos, 6(1): 41–51.
Beccaluva, L., Macciotta, G., Piccardo, G.B. and Zeda, O., 1989. Clinopyroxene composition of ophiolite basalts as petrogenetic indicator. Chemical Geology, 77(3–4): 165–182.
Best, M.G., 2003. Igneous and metamorphic petrology. Blackwell science ltd, Oxford UK, 729 pp.
Burnham, A.D. and Berry, A.J., 2014. The effect of oxygen fugacity, melt composition, temperature and pressure on the oxidation state of cerium in silicate melts. Chemical Geology, 366(1): 52–60.
Cameron, M. and Papike, J.J., 1981. Structural and chemical variations in pyroxenes. American Mineralogist, 66(1–2): 1–50.
Falahaty, S., Noghreyan, M., Sharifi, M., Torabi, G., Safaei, H. and Mackizadeh, M.A., 2016. Clinopyroxene application in petrogenesis identification of volcanic rocks associated with salt domes from Shurab (Southeast Qom). Journal of Economic Geology, 8(1): 21–38. (in Persian with English abstract)
France, L., Ildefonse, B., Koepke, J. and Bech, F., 2010. A new method to estimate the oxidation state of basaltic series from microprobe analyses. Journal of Volcanology and Geothermal Research, 189(3–4): 340–346.
Helz, R.T., 1973. Phase relations of basalts in their melting ranges at p H2O=5 kbar as a function of oxygen fugacity, Part I, Mafic phases. Journal of Petrology, 14(2): 249–302.
Kretz, R., 1983. Symbols for rock-forming minerals. American Mineralogist, 68(1–2): 277–279.
Kretz, R., 1994. Metamorphic Crystallization. John Wiley and Sons, Berlin, 530 pp.
Laubier, M., Grove, T.L. and Langmuir, C.H., 2014. Trace element mineral/melt partitioning for basaltic and basaltic andesitic melts: An experimental and laser ICP-MS study with application to the oxidation state of mantle source regions. Earth and Planetary Science Letters, 392(2): 265–278.
Le Bas, M.J., 1962. The role of aluminum in igneous clinopyroxenes with relation to their parentage. American Journal of Science, 260(4): 267–288.
Lindsley, I., 1983. Pyroxene thermometry. American Mineralogist, 68(5–6): 477–493.
Liotard, J.M., Briot, D. and Boivin, P., 1988. Petrological and geochemical relationships between pyroxene megacrysts and associated alkali-basalts from Massif Central 23 xenoliths suite (France). Contributions to Mineralogy and Petrology, 98(1): 81–90.
Mehvari, R., 2009. Petrological and mineralogical studies of the hydrothermal alteration (bentonitization and silicification), Molla Ahmad stiphiu, East of Isfahan. M.Sc. Thesis, University of Isfahan, Isfahan, Iran, 171 pp. (in Persian with English abstract)
Mehvari, R., Noghreyan, M., Sharifi, M., Mackizadeh, M.A., Tabatabaei, S.H. and Torabi, G., 2016. Mineral chemistry of clinopyroxene: guidance on geo-thermobarometry and tectonomagmatic setting of Nabar volcanic rocks, South of Kashan. Journal of Economic Geology, 8(2): 493–506. (in Persian with English abstract)
Morimoto, N., 1989. Nomenclature of pyroxenes. The Canadian Mineralogist, 27(1): 143–156.
Neave, D.A. and Putirka, K., 2017. A new clinopyroxene-liquid barometer, and implications for magma storage pressures under Icelandic rift zones. American Mineralogist, 102(1): 777–794.
Nimis, P. and Taylor, W.R., 2000. Single clinopyroxene thermobarometry for garnet peridotites. Part I. Calibration and testing of a Cr-in-Cpx barometer and an enstatite-in-Cpx thermometer. Contributions to Mineralogy and Petrology, 139(2): 541–554.
Nisbet, E.G. and Pearce, J.A., 1977. Clinopyroxene composition in mafic lavas from different tectonic setting. Contributions to Mineralogy and Petrology, 63(2): 149–160.
Princivalle, F., Tirone, M. and Comin- Chiaramonti, P., 2000. Clinopyroxenes from spinel-peridotite mantle xenoliths from Nemby (Paraguay): crystal chemistry and petrological implications. Mineralogy and Petrology, 70(1): 25–35.
Putirka, K., Mikaelian, H., Ryerson, F. and Shaw, H., 2003. New clinopyroxene–liquid thermobarometers for mafic, evolved, and volatile-bearing lava compositions, with applications to lavas from Tibet and the Snake River Plain, Idaho. American Mineralogist, 88(10): 1542–1554.
Putirka, K.D., 2008. Thermometers and barometers for volcanic systems. Reviews in Mineralogy and Geochemistry, 69(1): 61–120.
Ridolfi, F., Renzulli, A. and Puerini, M., 2010. Stability and chemical equilibrium of amphibole in calc- alkaline magmas: an overview, new thermobarometric formulations and application to subduction–related volcanoes. Contributions to Mineralogy and Petrology, 160(1): 45–66.
Sarabi, F., 2010. Optical mineralogy. University of Tehran, Tehran, 466 pp.
Sayari, M. and Sharifi, M., 2014. SCG: A computer application for single clinopyroxene geothermobarometry. Italian Journal of Geosciences, 133(2): 315–322.
Sayari, M. and Sharifi, M., 2016. Application of clinopyroxene chemistry to interpret the physical conditions of ascending magma, a case study of Eocene volcanic rocks in the Ghohrud area (North of Isfahan). Journal of Economic Geology, 8(1): 61–78. (in Persian with English abstract)
Schweitzer, E.L., Papike, J.J. and Bence, A.E., 1979. Statistical analysis of clinopyroxenes from deep-sea basalts. American Journal of Science, 64(5–6): 501–513.
Smythe, D.J. and Brenan, J.M., 2016. Magmatic oxygen fugacity estimated using zircon-melt partitioning of cerium. Earth and Planetary Science Letters, 453(1): 260–266.
Soesoo, A., 1997. A multivariate analysis of clinopyroxene composition: empirical coordinates for the crystallization P-T estimations. The Geological Society of Sweden, 119(1): 55–60.
Stöcklin, J., 1974. Possible ancient continental margin in Iran. In: C.A. Burk and C.L. Drake (Editors), The Geology of Continental Margin. Springer, Berlin, pp. 873–887.
Sun, C. M. and Bertrand, J., 1991. Geochemistry of clinopyroxenes in plutonic and volcanic sequences from the Yanbian Proterozoic ophiolites (Sichuan province, China): Petrogenetic and geotectonic implications. Schweizerische mineralogische und petrographische Mitteilungen, 71(2): 243–259.
Tamizi, N., 2013. Petrogaphy of volcanic rocks in the north of Aliabad mining area with emphasis on recent perlite and bentonite exploration works (NW Nain). M.Sc. Thesis, University of Isfahan, Isfahan, Iran, 95 pp. (in Persian with English abstract)
Zhu, Y.F. and Ogsasawara, Y., 2004. Clinopyroxene phenocrysts (with green salite cores) in trachybasalts: implications for two magma chambers under the Kokche NAPV UHP massif, North Kazakhstan. Journal of Asian Earth Sciences, 22(5): 517–527.
CAPTCHA Image