Clinopyroxene mineral chemistry of Peshtasar basalts, sedimentary basin of Moghan (NW Iran)
Subject Areas :
AbbasAli
Amrei
1
Reza
Zarei
2
Mohsen
Moayyed
3
Ahmad
Ahmadi
4
AmirMorteza
Azimzadeh
5
Keywords: Peshtasar basalt, Crystalization temperature Mineral chemistry, Clinopyroxene.,
Abstract :
With the east–west exposure trend, Peshtasar basalts are in the sedimentary basin of Moghan (Talesh structural zone), in the northwest of Iran.The Peshtasar complex lithologically includes basalt, andesitic basalt or basaltic andesite, megaporphyric andesite, leucite tephrite and volcanic breccia. The main constituent minerals are plagioclase, clinopyroxene, and iddingsitized olivine in basalts and plagioclase megacryst, clinopyroxene, and leucite in tephrite. The results of the microprobe analyses of clinopyroxene reveal the diopside composition. Clinopyroxenes of Peshtasar basalts have igneous nature originated from alkaline and continental magmatic serries. The results of termobarometry studies indicate the crystallization range from 800 -1200 degrees centigrade and crystallization pressure less than 5 kb. There was no water in composition of the parent magma of these rocks. The titanium contents of clinopyroxenes were low, indicating the presence of titano-magnetite (opaque minerals) in the rock. The ferric iron values in clinopyroxenes represents a high oxygen fugacity of magma.
آقانباتی، س.ع.، 1385. زمین‌شناسی ایران. انتشارات سازمان زمین‌شناسی و اکتشافات معدنی کشور، تهران.
بدیع الزمانی، خ.، 1347. مطالعه زمین‌شناسی جنوب خاوری مغان از نظر سنگ‌شناسی، چینه‌شناسی و امکانات نفتی. پایان‌نامه کارشناسی ارشد، دانشکده علوم، دانشگاه تهران. 117.
رحیم زاده، ف.، 1996. نقشه-های زمین‌شناسی زیوه و اصلاندوز (100000/1)، سازمان زمین‌شناسی کشور، تهران.
مبشر گرمی، م. و زارعی سهامیه، ر.، 1394. پتروگرافی و شیمی كانی منشورهای بازالتی جنوب شهرستان گرمی (جنوب حوزه تالش). یافته‌های نوین زمین‌شناسی كاربردی، 17، 79-90.
موید، م. و مجرد، م.، 1386. تکوین و تکامل اقیانوس پالئوتتیس دوم در ایران ؛ نقد فرضیات موجود – ارائه مدل جدید. یازدهمین همایش انجمن زمین‌شناسی ایران، دانشگاه فردوسی مشهد .
نبوی، م.ح.، 1355. دیباچه‌ای بر زمین‌شناسی ایران. سازمان زمین‌شناسی کشور.
Aoki, K. I. 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, 165-182.
Bence, A. E., Papike, J. J. and Ayuso, R. A., 1975. Petrology of Atlantic island arcs. Bulletin of Volcanology, 32, 189-206.
Berger, J., Femenias, O., Mercier, J. C. C. and Demaiffe, D., 2005. Ocean‐floor hydrothermal metamorphism in the Limousin ophiolites (western French Massif Central): evidence of a rare preserved Variscan oceanic marker. Journal of Metamorphic Geology, 23,9, 795-812.
Droop, G.T.R., 1987. A general equation for estimating of Fe3+ concentration in ferromagnesian silicates and oxides from microprobe analysis, using stoichiometric criteria, Mineralogical Magazine, 51, 431-435.
Gamble, R. P. and Taylor, L. A., 1980. Crystal/liquid partitioning in augite: effects of cooling rate. Earth and Planetary Science Letters, 47,1, 21-33.
Golonka, J., 2004. Plate tectonic evolution of the southern margin of Eurasia in the Mesozoic and Cenozoic. Tectonophysics, 381,1, 235-273.
Helz, R. T., 1973. Phase relations of basalts in their melting range at PH2O= 5 kb as a function of oxygen fugacity Part I. Mafic Phases. Journal of Petrology, 14,2, 249-302.
IFP., 1960. Geological Report Number. 235, NIOC, 10-20.
Kornprobst, J., Ohnenstetter, D. and Ohnenstetter, M., 1981. Na and Cr contents in clinopyroxenes from peridotites: a possible discriminant between “sub-continental” and “sub-oceanic” mantle. Earth and Planetary Science Letters, 53,2, 241-254.
Kretz, R., 1983. Symbols for rock-forming minerals. American Mineralogist, 68, 277-279.
Leterrier, J., Maury, R. C., Thonon, P., Girard, D. and Marchal, M., 1982. Clinopyroxene composition as a method of identification of the magmatic affinities of paleo-volcanic series. Earth and Planetary Science Letters, 59,1, 139-154.
Mahood, G. A. and Baker, D. R., 1986. Experimental constraints on depths of fractionation of mildly alkalic basalts and associated felsic rocks: Pantelleria, Strait of Sicily. Contributions to Mineralogy and Petrology, 93,2, 251-264.
Morimoto, N., 1988. Nomenclature of pyroxenes. Mineralogy and Petrology, 39,1, 55-76.
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, 139,5, 541-554.
Nisbet, E. G. and Pearce, J. A., 1977. Clinopyroxene composition in mafic lavas from different tectonic settings. Contributions to Mineralogy and Petrology, 63,2, 149-160.
Princivalle, F., Tirone, M. and Comin-Chiaramonti, P., 2000. Clinopyroxenes from metasomatized spinel-peridotite mantle xenoliths from Nemby (Paraguay): crystal chemistry and petrological implications. Mineralogy and Petrology, 70,1, 25-35.
Putirka, K. D., 2008. Thermometers and barometers for volcanic systems. Reviews in Mineralogy and Geochemistry, 69,1, 61-120.
Schweitzer, E.L., Papike, J. J. and Bence, A. E., 1979. Statistical analysis of clinopyroxenes from deep-sea basalts. American Mineralogist, 64,5-6, 501-513.
Soesoo, A., 1997. A multivariate statistical analysis of clinopyroxene composition: Empirical coordinates for the crystallisation PT‐estimations. GFF, 119,1, 55-60.
Zhu, Y. and Ogasawara, Y., 2004. Clinopyroxene phenocrysts (with green salite cores) in trachybasalts: implications for two magma chambers under the Kokchetav UHP massif, North Kazakhstan. Journal of Asian Earth Sciences, 22,5, 517-527.