Mineral chemistry and thermobarometry of mafic enclaves of Qezelje-Kand volcano, northeast of Qorveh, Kurdistan

Document Type : Original Article

Authors

1 Department of Mineral and Groundwater resource, School of Sciences, Shahid Beheshti University, Tehran, Iran

2 Department of Geology, Payam-e-Noor University, Tehran, Iran

Abstract

Introduction
Enclaves are divided into two categories: autolith (an enclave that is homogeneous with its host rocks) and xenolith (an enclave that is not homogeneous with its host rocks). Qezelje-Kand stratovolcano is located north of Sanandaj-Sirjan zone and in Tabriz-Hamadan volcanic belt. This volcano consists of a mixture of lava, bombs, scoria and ash, and several enclaves can be seen inside the lava and their ejecta. The felsic enclaves, which are pieces of bedrock, can be seen in different sizes from a few millimeters to a few decimeters, and the mafic enclaves can be seen from a few millimeters to a few centimeters. Due to the mineralogical similarity with the host rocks, there is a debate about whether they are autoliths or xenoliths. In this research, mafic enclaves including phlogopite-pyroxenite and pyroxenite have been studied. In this research, mafic enclaves including phlogopite-pyroxenite and pyroxenite have been studied. By using petrography and chemistry of minerals such as pyroxene and phlogopite and comparing them with the host volcanic rock as well as thermobarometry, the physical and chemical conditions of magma crystallization, magmatic origin and the possibility of autoliths or xenoliths of these enclaves have been investigated.
Materials and Methods
After fieldwork and sampling, thin sections were prepared for petrographic studies. Then, two enclave samples (including phlogopite-pyroxenite and pyroxenite) and one host volcanic rock sample were selected for Electron microprobe analysis, and their pyroxene and phlogopite minerals were analyzed. GCDkit, MagMin_PT, Excel and Corel draw software were used in data analysis and processing.
Results and Discussion
The minerals of phlogopite-pyroxenites include clinopyroxene, phlogopite and apatite with cumulate texture. Pyroxenite enclaves contain clinopyroxene with a small amount of phlogopite with granular texture. Host volcanic rocks are composed of pyroxene, plagioclase, olivine, biotite and hornblende with porphyric texture.
According to the results of the chemical analysis of the samples, the composition of pyroxenes of all three samples are calcium-magnesium-iron and clinopyroxene type. The chemical composition of phlogopite-pyroxenite, pyroxenite and host volcanic rock enclaves are Wo39.3-48.2-En39-54.2-Fs3.6-12.5, Wo43.1-49-En32-45-Fs8.6-18.9 and Wo42.8-46.2 -En42.6-46.5-Fs6.1-11.9. Clinopyroxenes are placed in the tetrahedral range in the Al and Si distribution diagram. Magnesium number for clinopyroxenites of phlogopite-pyroxenite sample is 0.76-0.90, for pyroxenite sample 0.64-0.84 and for host volcanic sample 0.78-0.88, which indicates the crystallization of clinopyroxenes of each three examples of a primary magma. By using the value of AlIV versus AlVI, the amount of water pressure at the time of crystallization for clinopyroxene of the phlogopite-pyroxenite sample and the host volcanic rock is 10% and less than 10% for the pyroxenite sample. The biotite of the phlogopite-pyroxenite sample and the host volcanic rock are of the phlogopite type and are re- equilibrate biotite in terms of their origin. In various diagrams drawn based on the chemistry of minerals, the position of clinopyroxenes of the phlogopite-pyroxenite sample is the same as the host volcanic rock, but they are not the same as the clinopyroxenites of the pyroxenite enclave sample. Due to the absence of minerals such as olivine, garnet and orthopyroxene in the enclaves and host volcanic rock, clinopyroxene was used for thermobarometry measurement. Two methods of clinopyroxene-melt and single clinopyroxene were used here. To use the clinopyroxene-melt method, if the value of KD (Fe-Mg exchange coefficient between melt and clinopyroxene) is 0.28 ± 0.08, it can be assumed that there was an equilibrium between the clinopyroxene mineral and the melt during crystallization. The KD of the pyroxenite enclave is greater than 0.28 and shows that it is not in equilibrium with the melt. The KD of the phlogopite-pyroxenite enclave and the host volcanic rock is 0.25-0.28 and 0.27, respectively, accordingly samples that are in equilibrium with the melt can be used for thermobarometry based on this method.
Conclusion
Based on the chemistry of the clinopyroxene crystals in the enclaves and the host rock, the composition of the magma is alkaline to sub-alkaline, it corresponds to the conditions of high oxygen fugacity and they came from a subduction-related tectonic origin. Also, the chemistry of phlogopite samples shows that these samples are composed of calc-alkaline magma in an orogenic environment. The calculated temperature for the phlogopite-pyroxenite enclave is 1150-1229 and for the host volcanic rock is 1190-1228ºC and the pressure calculated for them is 4.4-14 and 8-13 kb, respectively. According to the petrographic and geochemical evidence, it can be said that the phlogopite-pyroxenite sample is an autolith and is formed from the host magma, and the pyroxenite sample is probably a piece of mantle xenolith that was removed along with the eruption and reached the earth's surface.

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References

Abdel-Rahman, A., 1994. Nature of biotites from alkaline, calc-alkaline and peraluminous magmas: Journal of Petrology, v. 35, p. 525-541.
Abdel-Rahman, A.F.M., 1996. Discussion on the comment on nature of biotites in alkaline, calc-alkaline and peraluminous magmas. Journal of Petrology, v. 37(5), p. 1031-1035. Aghanabati, A. (2004). Geology of Iran. Geological survey of Iran, Tehran, 329 p (In Persian).
Aghanabati, A., 2004. Geology of Iran, Tehran, Geological Survey and Mineral Exploration of Iran (In Persian).
Ao, S.J., Xiao, W.J., Han, C.M., Mao, Q.G. and Zhang, J.E., 2010. Geochronology and geochemistry of early Permian mafic-ultramafic complexes in the Beishan area, Xinjiang, NW China: implications for late Paleozoic tectonic evolution of the southern Altaids", Gondwana Research, v. 18, p. 466-478.
Azizi, H. and Moinevaziri, H., 2009. Review of the tectonic setting of Cretaceous to Quaternary volcanism in northwestern Iran, Journal of Geodynamics, v. 47, p. 167-179.
Beccaluva, L., Macciotta, G., Piccardo, G.B. and Zeda, O., 1989. Clinopyroxene composition of ophiolite basalts as petrogenetic indicator. Chemical Geology, v. 77(3-4), p. 165-182.
Berberian, M., 1977. Three phase’s metamorphism in Hajiabad quadrangle (Southeastern extremity of the Sanandaj- Sirjan Structural zon): In contribution to the seisnotectonics of Iran (part 3), p. 239-260.
Botcharnikov, R.E., Koepke, J., Holtz, F., McCammon, C. and Wilke, M., 2005. The effect of water activity on the oxidation and structural state of Fe in a ferro-basaltic melt. Geochimica et Cosmochimica Acta, v. 69(21), p. 5071-5085.
Cundari, A. and Salviulo, G., 1989. Ti solubility in diopsidic pyroxene from a suite of New South Wales leucitites (Australia). Lithos, v. 22(3), p. 191-198.
Darvishzadeh, A. and Shahbazi, H., 2009. Genetic classification staratovolcano Xenoliths of Gezeljeh kand, NE of Qorveh, western Iran (In Persian).
Deer, W.A., Howie, R.A. and Zussman, J., 1987. Rock forming minerals, (2nd ed), SingleChain Silicates, Longman London, 668 p.
Dioh, E., Béziat, D., Grégoire, M. and Debat, P., 2009. Origin of rare earth element variations in clinopyroxene from plutonic and associated volcanic rocks from the Foulde basin, Northern Kedougou inlier, Senegal, West Africa. European Journal of Mineralogy, v. 21(5), p. 1029-1043.
Forster, M.D., 1960. Interpretation of the composition of trioctahedral micas: U.S. Geological Survey, v. 354, p. 11-49.
Golestani, M., 2020. Characteristics of tectono-magmatic alkali gabbros in northern Fathabad, Zarand (NW Kerman): based on the pyroxene mineral chemistry. Iranian journal of crystallography and mineralogy, v. 28(2), p. 311-328 (In Persian).
Griffin, W.L. and O'Reilly, S.Y., 1986. Mantle-derived sapphirine. Mineralogical Magazine, v. 50(358), p. 635-640.
Gündüz, M. and Asan, K., 2023. MagMin_PT: An Excel-based mineral classification and geothermobarometry program for magmatic rocks. Mineralogical Magazine, v. 87(1), p. 1-9.
Helz, R.T., 1973. Phase relations of basalts in their melting range at PH2O= 5 kb as a function of oxygen fugacity, Journal of Petrolology, v. 17, p. 139-193.
Holland, T.H., 1900. The charnockite series: a group of archæan hypersthenic rocks in peninsular India, v. 28(2). Sold at the Office of the Geological Survey.
Hosseini, M., 1999. Geological map 1:100000 Qorve, Geological Survey & Mineral Explorations of Iran (GSI), p. 465-468 (In Persian).
Kilinc, A., Carmichael, I.S.E., Rivers, M.L. and Sack, R.O., 1983. The ferric-ferrous ratio of natural silicate liquids equilibrated in air. Contributions to Mineralogy and Petrology, v. 83(1), p. 136-140.
Kord, M., 2013. Petrological study of ultramafic and gneissic enclaves of NE- Qorveh (Kurdistan). Master's thesis in petrology, Bou Ali Sina University, 139 p (In Persian).
Kretz, R., 1983. Symbols for rock-forming minerals. American mineralogist, v. 68(1-2), p. 277-279.
Lacroix, A., 1890. Sur les enclaves acides des roches volcaniques d'Auvergne. Bull. Serv. Carte Geol. Fr, v. 2, p. 25-56.
Le Bas, M.J., 1962. The role of aluminum in igneous clinopyroxenes with relation to their parentage. American Journal of Science, v. 260(4), p. 267-288.
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, v. 59(1), p. 139-154.
Loucks R.R., 1990. Discrimination of ophiolitic from nonophiolitic ultramafic-mafic allochthons in orogenic belts by the Al/Ti ratio in clinopyroxene, Geology, v. 18, p. 346-349.
Moinvaziri, H., 1999. Introduction to the Magmatism of Iran. Tarbiat Moallem University, Tehran (In Persian).
Morimoto, N., 1988. Nomenclature of pyroxenes, Fortschr mineral, v. 66, p. 237-252.
Morimoto, N., Fabrise, J., Ferguson, A., Ginzburg, I.V., Ross, M., Seifert, F.A., Zussman, J., Akoi, K.I. and Gottardi, G., 1988. Nomenclature of pyroxenes, Mineralogical Magazine, v. 52, p. 535-550.
Morimoto, N. and Kitamura, M., 1983. QJ diagram for classification of pyroxenes. Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists, v. 78, p. 128-141.
Nachit, H., Ibhi, A., Abia, E.H. and Ohoud, M.B., 2005. Discrimination between primary magmatic biotites, reequilibrated biotites and neoformed biotites. Comptes rendus Geoscience, v. 337, p. 1415-1420.
Nimis, P., 1995. A clinopyroxene geobarometer for basaltic systems based on crystalsstructure modeling. Contributions to Mineralogy and Petrology, v. 121, p. 115-125.
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, v. 139, p. 541-554.
Nimis, P. and Taylor, W.R., 2000. Single clinopyroxene thermobarometry for garnet peridotites. Part 1 Calibration and testing of a Cr-in-cpx barometer and an enstatite-in-cpx thermometer. Contributions to Mineralogy and Petrology, v. 139, p. 541-554.
Nimis, P. and Ulmer, P., 1998. Clinopyroxene geobarometry of magmatic rocks. Part 1: an expanded structural geobarometer for anhydrous and hydrous basic and ultrabasic systems. Contributions to Mineralogy and Petrology, v. 133, p. 122-135.
Nisbet, E.G. and Pearce, J.A., 1977. Clinopyroxene composition in mafic lavas from different tectonic settings. Contributions to mineralogy and petrology, v. 63(2), p. 149-160.
Nosova, A.A., Narkisova, V.V., Sazonova, L.V. and Simakin, S.G., 2002. Minor elements in clinopyroxene from Paleozoic volcanics of the Tagil island arc in the Central Urals. Geochemistry international, v. 40(3), p. 219-232.
Papike, J.J., 1974. Amphiboles and pyroxenes: Characterization of other than quadrilateral components estimates of ferric iron from microprobe data. In Geological Society of America Abstract with Programs, v. 6, p. 1053-1054.
Putirka, K., 2008. Thermometers and barometers for volcanic systems. Mineralogical Society of America, v. 69, p. 61-120.
Putirka, K., Johnson, M., Kinzler, R., Longhi, J. and Walker, D., 1996. Thermobarometry of mafic igneous rocks based on clinopyroxene-liquid equilibria, 0–30 kbar. Contributions to Mineralogy and Petrology, v. 123, p. 92-108.
Putirka, K., Ryerson, F.J. and Mikaelian, H., 2003. New igneous thermobarometers for mafic and evolved lava compositions, based on clinopyroxene + liquid equilibria. American Mineralogist, v. 88, p. 1542-1554.
Rieder, M. and et al, 1998. Nomenclature of the micas. The Canadian Mineralogist, v. 36, p. 905-912.
Schweitzer, E.L., Papike, J.J. and Bence, A.E., 1979. Statistical analysis of clinopyroxenes from deep-sea basalts. American Mineralogist, v. 64(5-6), p. 501-513.
Shabniyan, N., Davoodian Dehkordi, A.R. and Soheilian, F., 2013. Tectono-magmatic characteristics of Bagham pluton in southeastern Ardestan: Base on mineral chemistry of clinopyroxene and amphibole. Iranian Journal of Crystallography and Mineralogy, v. 21, p. 471-486 (In Persian).
Sollas, W.J., 1892. On the volcanic district of Carlingford and Slieve Gullion. Part I.: On the Relation of the Granite to the Gabbro of Barnavave, Carlingford. The Transactions of the Royal Irish Academy, v. 30, p. 477-512.
Speer, J.A., 1984. Mica in igneous rocks. In: Bailey SW (ed) Micas. Reviews in Mineralogy, v. 13, p. 299-356.
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, v. 71, p. 243-259.
Veysi, S., Asibahanha, A., Shahbazi, H. and Nasrabadi, M., 2014. The enclaves of the scoria cone of Qazjeh Kand (north of Qorveh), xenolite or cumula?, Journal of Geology of Iran, v. 9(34), p. 70-51 (In Persian).
Yavuz, F., 2013. WinPyrox: A Windows program for pyroxene calculation classification and thermobarometry. American Mineralogist, v. 98(7), p. 1338-1359.
 
 
 

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