Petrology and geochemistry of the metamorphic rocks in the SW Arak and it’s comparison with neighboring areas

Abstract

Metamorphic rocks in SW Arak composed from two groups including regional and contact metamorphism. Regional metamorphic rocks are composed of slate, phyllite and micaschists and locted in green-schist facies and contact metamorphic rocks are composed of spotted schist and hornfels respectively. Mineralogically, these rocks are composed of quartz, chlorite, muscovite, biotite and cordierite. Petrographic studies of these rocks show that cordierite mineral formed during contact metamorphism. On the basis of mineral chemistry, the Chlorite has ripidolite compositions and muscovite is rich in the muscovite end-member. Based on calculations, chlorite mineral in regional metamorphic rocks in the study area have formed at temperature of 387-416 ºC and low-to medium pressure. According to the microscopic studies, field observations and obtained analyses of samples from different protoliths, the rocks have been sedimentary and graywacke or shale type. Major and trace elements concentration (e.g. K2O, TiO2, Rb, Ni) indicates that the primary igneous rocks was acidic (andesite to rhyodacite). In comparison with average of upper continental crust, the rocks of studied area of P, Sr, Ba, Ti negative anomalies and of Rb, K positive anomalies that cause replacements of these elements during metamorphism and alteration. Discriminations diagrams of tectonic setting indicate a subduction Zone. Using major oxides elements, the continental active margins considered for metapelites source.

Keywords

References

[1] سهندی م.، رادفر ج.، حسینی دوست س.ج.، محجل م.، ″نقشه 1:100000 شازند، سازمان زمین شناسی و اکتشافات معدنی کشور″، برگ شماره 5857 (1385).

[2] محجل م.، سهندی م.، ″تکامل تکتونیکی پهنه سنندج- سیرجان در نیمه شمال باختری و معرفی زیرپهنه‌های جدید در آن″، فصلنامه علمی- پژوهشی علوم زمین، شماره ٣٢-٣١ (١٣٧٨)، ص ٤٩-٢٨.

[3] Mahmoudi S., Corfu F., Masoudi F., Mehrabi B., Mohajjel M., ″U–Pb dating and emplacement history of granitoid plutons in the northern Sanandaj–Sirjan Zone, Iran″, Journal of Asian Earth Sciences 41 (2011) 238-249.

[4] رادفر ج.، ″بررسی‌های زمین‌شناسی و پترولوژی سنگ‌های گرانیتوئیدی ناحیه آستانه- گوشه″، پایان‌نامه کارشناسی ارشد، دانشکده علوم، دانشگاه تهران، (1366).

[5] سهیلی م.، ″نقشه زمین‌شناسی١:25٠٠٠٠ خرم‌آباد″، سازمان زمین شناسی و اکتشافات معدنی کشور″، برگ شماره D7 (١٣٧١).

[6] Berthier F., Billiaul H.P., Halbroronn B. Marizot P., ″Etude Stratigraphique, petrologique et structural de La region de Khorramabad (Zagros, Iran) ″, These De 3e cycle, Grenoble, (1974).

[7] Masoudi F., ″Contact metamorphism and pegmatite development in the region SW of Arak, Iran″, PhD Thesis, Leeds University, UK (1997).

[8] سپهوند ف.، ″ژئوشیمی و تعیین محیط تکتونیکی سنگ‌های دگرگونی منطقه آستانه (جنوب‌غرب اراک)″، پایان‌نامه کارشناسی ارشد، دانشکده علوم، دانشگاه لرستان، (1392).

[9] حسنوند م.، ″پتروژنز و ژئوشیمی سنگ های دگرگونی منطقه شمال غربی الیگودرز″، پایان‌نامه کارشناسی ارشد، دانشگاه آزاد اسلامی واحد خوراسگان، (1390).

[10] حسنوندی ا.، ″بررسی پتروژنز و ژئوشیمی سنگ‌های دگرگونی منطقه بروجرد″، پایان‌نامه کارشناسی‌ارشد، دانشگاه آزاد اسلامی واحد خوراسگان، (1389).

[11] طهماسبی ز.، احمدی خلجی ا.، رجاییه م.، ″تورمالین زائی در توده گرانیتوئیدی آستانه (جنوب غرب اراک)″، مجله بلورشناسی و کانی شناسی ایران، شماره 3 (1388) ، ص369-380.

[12] Barker A.J., "Introduction to metamorphic textures and microstructures", Blackie, Glasgow (1990) 162.

[13] Hey M.H., ″A new review of the chlorites″, mineralogical Magazine 30 (1954) 277-292.

[14] Pflumio C., ″Evidences for polyphased oceanic alteration of the extrusive sequence of the Semail ophiolite from the Salahi Block (Oman) ″, in: Peters, T.J.(Eds), Ophiolite genesis and evolution in the oceanic lithosphere, (1991) 313-351.

[15] Bailey S. W., ″Summary of recommendations of AIPEA Nomenclature Committee″. Clays and Clay Minerals 15 (1980) 85-93.

[16] Munguira A.L., Nieto F., Morata D., ″Chlorite composition and geothermometry: a comparative HRTEM/AEM-EMPA study of Cambrian basic lavas from the Ossa Morena Zone, SW Spain″, Clay Minerals 37 (2002) 267–281.

[17] McDowell S.D., Elders W.A., ″Authigenic layer silicate minerals in borehole Elmore 1, Salton Sea geothermal field, California, USA″, Contributions to Mineralogy and Petrology 74 (1980) 293-310.

[18] Cathelineau M., Nieva D., ″A chlorite solid solution geothermometer, The Los Azufres (Mexico) geothermal system″, Contributions to Mineralogy and Petrology 91 (1985) 235-244.

[19] Cathelineau M., ″Cation site occupancy in chlorites and illites as a function of temperature″, Clay Minerals 23 (1988) 471-485.

[20] Laid J., ″Chlorites: metamorphic petrology. In: Hydrous Phyllosilicates (et Baily, S.W.)″, Mineralogical Society of America, Reviews in Mineralogy 19 (1988) 405-453.

[21] Feenstra A., ″An EMP and TEM-AEM study of margarite, muscovite and f paragonite in polymetamorphic metabauxites of Naxos (Cyclades, Greece) and the implications of fine-scale mica interlayering and multiple mica generations″, Journal of Petrology 37 (1996) 201-233.

[22] Miller C.F., Stoddard E.F., Bradfish L.J., Dollase W.A., ″Composition of plutonic muscovite: genetic implications″, The Canadian Mineralogist 19 (1981): 25-34.

[23] Schliestedt M., "Phasengleichgewichte in Hoch druckgesterinen von Sifnos", Griechen land. Ph.D. Thesis, Technical University Braunschweig, Germany, (1980) 142.

[24] Lambert R.St.J., ″The mineralogy and metamorphism of the Moine schists of The Morar and Kroydart districts of Inverness-shire″, Transactions of the Royal Society of Edinburgh 63 (1959) 553.

[25] Kranidiotis P., Maclean W.H., ″Systematics of Chlorite alteration at the Phelps Dodgc massive sulfide deposit, Matagami, Quebec″, Economic Geology 82 (1987) 1898-1911.

[26] Jowett E.C., ″Fitting iron and magnesium into the hydrothermal chlorite geothermometer: GAC/MAC/SEGJoint Annual Meeting (Toronto, May 27-29, 1991) ″, Program with Abstracts 16 (1991) A62.

[27] Xie X., Byerly G.R., Ferrell R.E., ″IIb trioctahedral chlorite from the Barberton greenstone belt: crystal structure and rock composition constraints with implications for geothermometry″, Contributions to Mineralogy and Petrology 126 (1997) 275-291.

[28] Winkler H.G.F., ″Abolition of metamorphic facies″, Fortrschr. Mineral 47 (1970) 84-105.

[29] Pettijohn F.S., Potter P. E., Siever R., ″Sand and Sandstones″, Springer-Verlag, New York, (1972) 290.

[30] Herron M.M., ″Geochemical classification of terrigenous sands and shales from core or log data″, Journal of Sedimentary Petrology 58 (1988) 820-829.

[31] Garcia D., Fonteilles M., Moutte J., ″Sedimentary fractionations between Al, Ti, and Zr and the genesis of strongly peraluminous granites″, Journal of Geology 102 (1994) 411-322.

[32] Werner C.D., ″Saxonian granulites-igneous or lithogenous, A contribution to the geochemical diagnosis of the original rocks in high-metamorphiccomplexes″, ZfI-Mitteilungen 133 (1987) 221-250.

[33] Roser B.P., Korsch R.J., ″Provenances signatures of sandstone-mudstone suites determined using discriminate function analysis of major-element data″, Chemical Geology 67 (1988) 119-139.

[34] Floyd P.A., Winchester J.A., Park R.G., ″Geochemistry and tectonic setting of Lewisian clastic metasediments from the early Proterozoic Lock Marie Group of Gairlock″, Scotland, Precambrian Research 45 (1989) 203-214.

[35] Hallberg J.A., ″A geochemical aid to igneous rock identification in deeply weathered terrain″, Journal of Geology Exploration 20 (1984) 1-8.

[36] Winchester J.A., Floyd P.A., ″Geochemical discrimination of different magma series and their differentiation products using immobile elements″, Chemical Geology 20 (1977) 325-343.

[37] Vergara M., Levi B., Nystrom J.O., Cancino A., ″Jurassic and Early Cretaceous island arc volcanism, extension, and subsidence in the Coat Range of central Chile″, Geology Society of American Bulletin 107 (1995) 1427-1440.

[38] Nesbitt H.W., Young G.M., ″Prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations″, Geochimica et Cosmochimica Acta 48 (1984) 1523-1534.

[39] Fedo C.M., Nesbitt H.W., Young G.M., ″Unravelling the effects of potassium metasomatism in sedimentary rocks and paleosols with implications for paleoweathering conditions and provenance″, Geology 23 (1995) 921-924.

[40] Fedo C.M., Young G.M., Nesbitt H.W., Hanchar J.M., ″Potassic and sodic metasomatism in the Southern Province of the Canadian Shield: evidence from the Paleoproterozoic Serpent Formation, Huronian Supergroup″, Canadian Precambrian Research 84 (1997) 17-36.

[41] Bhatia M.R., Crook K.A.W., ″Trace element characteristics of graywackes and tectonic discrimination of sedimentary basins″, Contributions to Mineralogy and Petrology 92 (1986) 181-193.

[42] Bhatia M.R., ″Plate tectonics and geochemical composition of sandstones″, Journal of Geology 92 (1983) 181-193.

[43] Petersen N., Smith P.L., Mortensen J.K., Creaser R.A., Tipper H.W., ″Provenance of Jurassic sedimentary rocks of south-central Quesnellia″, British Colombia: implications for paleogeography, Canadian Journal of Earth Sciences 41 (2004) 103-125.

[44] Nakamura N., ″Determination of REE, Ba, Fe, Mg, Na, and K in carbonaceous and ordinary chondrites″, Geochimica et Cosmochimica Acta 38 (1974) 757–775.

[45] Thompson A.B., ″Magmatism of the Bristish Terciary volcanic Province″, Scottish Journal of Geology 18 (1982) 50–107.









[46] Wilson M., ″Igneous petrogenesis″, Unwin Hyman London, (1989) 466.

[47] Arsalan M., Aslan Z., ″Mineralogy, petrography and whole-rock geochemistry of the Tertiary granitic intrusions in the Eastern Pontides, Turkey″, Journal of Asian Earth Sciences 27 (2006) 177-193.

[48] Rogers G., Hawkesworth C.J., ″A geochemical traverse across the North Chilean Andes: evidence for crust generation from the mantle wedge″, Earth and Planetary Science Letters 91 (1989) 271–285.

[49] Sajona F.G., Maury R.C., Bellon H., Cotton J., Defant M., ″High field strength elements of Pliocene-Pleistocene island-arc basalts Zamboanga Peninsula, Western Mindanao (Philippines)″, Journal of Petrology 37 (1996) 693–726.

[50] Pearce J.A., Norry M.J., ″Petrogenetic implication of Ti, Zr, Y and Nb variations in volcanic rocks″, Contributions to Mineralogy and Petrology 69 (1979) 33-51.

[51] Shahabpour J., ″Tectonic evolution of the orogenic belt in the region located between Kerman and Neyriz″, Journal of Asian Earth Sciences 24 (2005) 405-417.

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  • Receive Date: 02 July 2025
  • Revise Date: 04 February 2026
  • Accept Date: 02 July 2025

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