Study of Migmatization and Leucocrate granite formation processes in the Tuyserkan area, Hamedan

Document Type : Research Article

Authors

• Masoumeh Zare Shooli ¹
• Zahra Tahmasbi ¹
• Adel Saki ²
• Ahmad Ahmadi Khalaji ¹

¹ Lorestan University

² Shahid Chamran University of Ahvaz

10.22067/econg.v12i1.75143

Abstract

Introduction
Partial melting is an appropriate correlation process between metamorphism and magmatism which plays a key role in the development of migmatites, granulites and S-type granites during crust evolution (Kriegsman, 2001; Alvarez-Valero and Kriegsman, 2008; Sawyer, 2010). In this study, we tried to address the correlation between partial melting process and metapelites migmatization and the formation of adjacent granites through microscopic and field evidence and geochemical data.
 
Materials and methods
Petrography and field studies were carried out and in order to identify minerals’ composition and determine temperature and pressure. A few spots of different minerals were analyzed by microprobe electron method with CAMECA device model SX100 at the Geosciences Research Institute of China University. Also, in order to evaluate the geochemical and the correlation between migmatites, leucocratic granite and metapelites, several samples of the mentioned rocks were selected. Their major and minor elements were respectively analyzed by the XRF and ICP-MS methods at Beijing University of China.
 
Results
While the pattern of rare earth elements (REE) in migmatite leucosome and adjacent granites shows that leucosome and leucocratic granite do not have the same origin, the leucocratic granite influence has occurred after the migmatization event, geothermobarometric calculations of migmatites and intrusive bodies as well as age measurement of Alvand Plutonic mass and migmatite rocks confirm that anatexis and partial melting do not come from granitic body heat but also heat of older mafic bodies is the cause of partial melting and migmatization in the region. Therefore, migmatites have emerged because of contact metamorphism which itself is the result of injection of the same age mafic bodies with migmatites.
 
Discussion
Migmatites of the study area are composed of quartz, plagioclase, potassium feldspar, biotite, andalusite, cordierite, spinel, and sillimanite minerals. Temperature and pressure for metamorphism peak are approximately 700 ° C and 4 kbar, respectively. Based on these data, the formation depth of these rocks is about 11 km. Therefore, their geothermal gradient is 54 °C/km which is located in the contact metamorphism zone and the Buchan type metamorphism series and it is in accordance with high temperature-low pressure metamorphisms. Migmatites are located near the leucocratic granite in some parts of Tuyserkan. However, they do not have any contact with granites in other parts but they have outcrops with hornfels rocks instead. The pattern of rare earth elements (REE) has been used to find out the migmatites protolith in the Hamadan area. Since, the pattern of rare earth elements (REE) of migmatites and metapelites has a similar process, this lithology has been used as a probable protolith. In order to identify the distributed elements inside the molten or in the residual (restite), the average chemical composition of probable protolith (cordierite hornfels) was used as a normalization standard for restite geochemistry in multi-element diagrams. According to spider diagrams pattern (mesosome, leucosome) normalized to the average metapelites based on mass balance, it can be concluded that migmatites have been formed by evolution of cordierite hornfels. In order to investigate the origin and possible relations between leucosome and adjacent granites (leucocratic granite), the chemical composition of these rocks was compared. Leucocratic granite located in the migmatites immediate contact and leucosome which is a few centimeters thick are considered in this comparison. The pattern of rare earth elements (REE) shows a significant difference in the migmatite leucosome and adjacent granites. The most important results of REE patterns is the difference in HFSE value in granites and leucosome. Thermometry has been conducted on intrusive masses (gabbro) through various methods and by Sepahi et al. (2012). The approximate temperatures of 950 ° C for gabbro and 1300 ° C for olivine gabbro are estimated. Also, due to contact metamorphism reactions, the maximum contact temperature of porphyry granites (Alvand intrusive mass) is estimated to be about 530 to 550 ° C (Sepahi and Moein Vaziri, 2001). Such a temperature is not sufficient for migmatization in the region. Shahbazi et al. (2010) have acquired the age of Alvand plutonic rocks to be 166.5 ± 1.8 Ma for gabbro, 163.0 ± 9.9 and 161.7 ± 0.6 Ma for granites and 154.4 ± 1.3 and 153.3 ± 2.7 Ma for leucocratic granite. Jafari (2018) has acquired the age of Hamadan's Migmatites to be about 160 to 180 Ma and an average of 170 million years which is almost equal to the age of Alvand Plutonic body.
 
 
References
Alvarez-Valero, A.M. and Kriegsman, L.M., 2008. Partial crustal melting beneath the Betic Cordillera (SE Spain), the case study of Mar Menor volcanic suite. Lithos, 101(3): 379–396.
Jafari, S.R., 2018. Petrology of High Grade metamorphic rocks of the Hamedan and the adjasent areas in the Sanandaj-Sirjan Zone. Ph.D. Thesis, Bu-Ali Sina University, Hamedan, Iran, 201 pp. (in Persian with English abstract)
Kriegsman, L.M., 2001. Partial melting, partial melt extraction and partial back reaction in anatectic migmatites. Lithos, 56‌(1): 75–96.
Sawyer, E.W., 2010. Migmatites formed by water-fluxed partial melting of a leucogranodiorite protolith: Microstructures in the residual rocks and source of the fluid. Lithos, 116‌(3–4): 273–286.
Sepahi, A.A., Borzoei, K. and Salami, S., 2012. The study of minerals chemistry, thermobarometry and tectonic setting of plutonic rocks from Sarabi Tueyserkan area (Hamedan province). Petrology, 3(11): 39–58. (in Persian with English abstract)
Sepahi, A.A. and Moein vaziri, H., 2001. New findings on metamorphic rocks and adjacent megametates of the Alvand plutonic complex. Research Journal of University of Isfahan "Science", 15(1–2): 37–52. (in Persian)
Shahbazi, H., Siebel, W., Pourmoafee, M., Ghorbani, M., Sepahi A.A., Shang, C.K. and Vousoughi Abedini, M., 2010. Geochemistry and U-Pb zircon geochronology of the Alvand plutonic complex in Sanandaj- Sirjan Zone (Iran): New evidence for Jurassic magmatism. Journal of Asian Earth Sciences, 39‌(6): 668–683.

Keywords

• migmatites
• partial melting
• leucocratic granite
• Tuyserkan
• Hamadan
• Sanandaj-Srjan zone

20.1001.1.20087306.1399.12.1.2.9

---

References

Ahmadi Khalaji, A. and Tahmasebi, Z., 2016. Mineral chemistry of garnet in pegmatite and metamorphic rocks in the Hamedan area. Journal of Economic Geology, 7(2): 243–258. (in Persian with English abstract)

Alavi, M., 1994. Tectonics of the Zagros orogenic belt of Iran, New data and interpretations. Tectonophysics, 229(4): 211–238.

Alavi, M., 2004. Regional stratigraphy of the Zagros fold-thrust belt of Iran and its pro foreland evolution. American Journal of Science, 304(1): 1–20.

Aliani, F., Sabouri, Z., Maanijou, M. and Sepahi, A.A., 2011. Litology and Geochemistry of hololeucocrate granitoids of Alvand granitoid mass (Hamadan). Iranian Journal of Crystallography and Mineralogy, 19(1):133–144. (in Persian)

Alvarez-Valero, A.M. and Kriegsman, L.M., 2008. Partial crustal melting beneath the Betic Cordillera (SE Spain), the case study of Mar Menor volcanic suite. Lithos, 101(3): 379–396.

Baharifar, A.A., 1997. New perspective on petrogenesis of the regional metamorphic rocks of Hamedan area, Iran. M.Sc. Thesis, Tarbiat Moallem University of Tehran, Tehran, Iran, 170 pp. (in Persian with English abstract)

Baharifar, A., Moinevaziri, H., Bellon, H. and Pique, A., 2004. The crystalline complexes of Hamadan (Sanandaj-Sirjan zone, western Iran): Metasedimentary Mesozoic sequences affected by Late Cretaceous tectono-metamorphic and plutonic events, 40 K-40 Ar dating. Comptes Rendus Geoscience, 366(16): 1443–1452.

Bea, F., Pereira, M.D. and Stroh, A., 1994. Mineral/leucosome the trace-element partitioning in peraluminous migmatite (a laser ablation-ICP-MS study). Chemical Geology, 117(1–4): 291–312.

Berberian, M. and King, G.C.P., 1981. Towards a paleogeography and tectonic evolution of Iran. Canadian Journal of Earth Sciences, 18(11): 210–265.

Boynton, W.V., 1984. Cosmochemistry of the rare earth elements, meteorite studies. In: P. Henderson (Editor), Rare earth element geochemistry. Elsevier Scientific Publishing Company, Amsterdam, pp. 63–114.

Coleman, R.G., Lee, D.E., Beatty, L.B. and Brannock, W.W., 1965. Eclogites and eclogites: their differences and similarities. Geological Society America Bulletin, 76(5): 483–508.

Corona-Chavez, P., Poli, S. and Bigioggero, B., 2006. Syn-deformational migmatites and magmatic-arc metamorphism in the Xolapa Complex, southern Mexico. Journal of Metamorphic Geology, 24(3): 169–191.

Dale, J. and Holland, T.J.B., 2003. Geothermobarometry, P-T paths and metamorphic field gradients of high-P rock from the Adula Nappe, Central Alps. Journal of Metamorphic Geology, 21(8): 813–829.

Deer, W.A., Howie R.A. and Zussman, J., 1962. Rock- forming minerals. Longman, London, 528 pp.

Fyfe, W.S., 1973. The granulite facies, partial melting and the Archaean crust. Royal Society of London Philosophical Transactions A, 273(1235): 457–461.

Gardien, V., Thompson, A.B., Grujic, D. and Ulmer, P., 1995. Experimental melting of biotite + plagioclase + quartz + orthose + muscovite assemblage and implication for crustal melting. Journal of Geophysical Research, 100(B8) 15581–15591.

Genier, F., Bussy, F., Epard, J.L. and Baumgartner, L., 2008. Water-assisted migmatization of metagraywackes in a Variscan shear zone, Aiguilles-Rouges massif, western Alps. Lithos, 102(3–4): 575–597.

Harris, N., Ayres, M. and Massey, J., 1995. Geochemistry of granitic melts produced during the incongruent melting of muscoviteimplications for the extraction of Himalayan leucogranite magmas. Journal of Geophysical Research, 100(B8): 15767–15777.

Holdaway, M.J. and Mukhopadhyay, B., 1993. A re-evaluation of the stability relations of andalusite: thermochemical data and phase diagram for the aluminum silicates. American Mineralogist, 78(3–4): 298–315.

Holland, T.J.B. and Powell, R., 1998. An internally consistent thermodynamic data set for phases of petrological interest. Journal of Metamorphic Geology, 16(3): 309–344.

Jafari, S.R., 2018. Petrology of High Grade metamorphic rocks of the Hamedan and the adjasent areas in the Sanandaj-Sirjan Zone. Ph.D. Thesis, Bu-Ali Sina University, Hamedan, Iran, 201 pp. (in Persian with English abstract)

Jung, S., Mezger, K., Masberg, P., Hoffer, E. and Hoernes, S., 1998. Petrology of an intrusionrelated high-grade migmatite - implications for partial melting of metasedimentary rocks and leucosome-forming processes. Journal of Metamorphic Geology, 16(3): 425–445.

Kretz, R., 1983. Symbols for rock-forming minerals. American Mineralogist, 68(1): 277–279.

Kriegsman, L.M., 2001. Partial melting, partial melt extraction and partial back reaction in anatectic migmatites. Lithos, 56(1): 75–96.

Lancaster, J., Fu, B., Page, F.Z., Kita, N.T., Bickford, M.E., Hill, B.M., Mclelland, J.M. and Valley, J.W., 2009. Genesis of metapelitic migmatites in the Adirondack Mountains. Journal of Metamorphic Geology, 27(1): 41–54.

McMillan, A., Harris, N.B.W., Ashwal, M.H.L., Kelley, S. and Rambeloson, R., 2003. A granite-gabbro complex from Madagascar: constraints on melting of the lower crust. Contribution to Mineralogy and Petrology, 145(5): 585–599.

Miller, C.F., 1985. Are strongly per-aluminous magmas derived from mature sedimentary (pelitic) sources? The Journal of Geology, 93(6): 673–689

Mohajjel, M. and Fergusson, C.L., 2000. Dextral transpression in Late Cretaceous continental collision, Sanandaj-Sirjan Zone, western Iran. Journal of Structural Geology, 22(8): 1125–1139.

Mohajjel, M., Fergusson, C.L. and Sahandi, M.R., 2003. Cretaceous-Tertiary convergence and continental collision, Sanandaj-Sirjan zone, Western Iran. Journal of Asian Earth Sciences, 21(4): 397–412.

Nehring, F., Foley, S.F. and Hölttä, P., 2010. Trace element partitioning in the granulite facies. Contributions to Mineralogy and Petrology 159‌(4): 493–519.

Patino Douce, A.E. and Harris, N., 1998. Experimental constraints on Himalayan anatexis. Journal of Petrology, 39‌(4): 689–710.

Saki, A., 2010a. Proto-Tethyan remnants in northwest Iran Geochemistry of the gneisses and metapelitic rocks. Gondwana Research, 17(4): 704–714.

Saki, A., 2010b. Mineralogy, geochemistry and geodynamic setting of the granitoids from NW Iran. Geological Journal, 45(4): 1–16.

Saki, A., Moazzen, M. and Baharifar, A.A., 2012. Migmatite microstructures and partial melting of Hamadan metapelitic rocks, Alvand contact aureole, western Iran. International Geology Review, 54(11): 1229–1240.

Saki, A. and Pourkaseb, H., 2012. Study of the physico- chemical conditions of the formation of skarns in Alvand batolith with metacarbonate rocks. Journal of Economic Geology, 4(1): 123–134. (in Persian with English abstract)

Sawyer, E.W., 1996. Melt segregation and magma flow in migmatites: implications for the generation of granite magmas, Transactions. Earth and Environmental Science Transactions of The Royal Society of Edinburgh, 87(1–2): 85–94.

Sawyer, E.W., 2008. Working with migmatites, Mineralogical Association of Canada Short Course. Quebec City, Quebec, v. 38, 168 pp.

Sawyer, E.W., 2010. Migmatites formed by water-fluxed partial melting of a leucogranodiorite protolith: Microstructures in the residual rocks and source of the fluid. Lithos, 116(3–4): 273–286.

Sepahi, A.A., Borzoei, K. and Salami, S., 2012. The study of minerals chemistry, thermobarometry and tectonic setting of plutonic rocks from Sarabi Tueyserkan area (Hamedan province). Petrology, 3(11): 39–58. (in Persian with English abstract)

Sepahi, A.A., Jafari, S.R. and Mani-Kashani, S., 2009. Low pressure migmatites from the Sanandaj-Sirjan Metamorphic Belt in the Hamedan region (Iran). Geologica Carpathica, 60(2): 107–119.

Sepahi, A.A. and Moein vaziri, H., 2001. New findings on metamorphic rocks and adjacent megametates of the Alvand plutonic complex. Research Journal of University of Isfahan "Science", 15(1–2): 37–52. (in Persian)

Shahabpour, J., 2005. Tectonic evolution of the orogenic belt in the region located between Kerman and Neyriz. Journal of Asian Earth Sciences, 24(4): 405–417.

Shahabpour, J., 2007. Island-arc anity of the Central Iranian Volcanic Belt. Journal of Asian Earth Sciences, 30(5–6): 652–665.

Shahbazi, H., Siebel, W., Pourmoafee, M., Ghorbani, M., Sepahi A.A., Shang, C.K. and Vousoughi Abedini, M., 2010. Geochemistry and U-Pb zircon geochronology of the Alvand plutonic complex in Sanandaj- Sirjan Zone (Iran): New evidence for Jurassic magmatism. Journal of Asian Earth Sciences, 39(6): 668–683.

Sheikholeslami, M.R., Pique, A., Mobayen, P., Sabzehei, M., Bellon, H. and Hashem Emami, M., 2008. Tectono-metamorphic evolution of the Neyriz metamorphic complex, Quri-Kor-e-Sefid area (Sanandaj-Sirjan Zone, SW Iran). Journal of Asian Earth Sciences, 31(4–6): 504–521.

Sun, S.S. and McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: A.D. Saunders and M.J. Norry (Editors), Magmatism in Ocean Basins. Geological Society, London, Special Publications, pp. 313–345.

Vielzeuf, D. and Holloway, J.R., 1988. Experimental determination of the fuild-absent melting relations in the pelitic system. Contributions to Mineralogy and Petrology, 98(3): 257–276.

White, A.J.R. and Chappell, B.W., 1977. Ultrametamorphism and granitoid genesis. Tectonophysics, 43(1–2): 7–22.