Document Type : Original Research Paper

Authors

1 Ph.D. Student, Department of Geology, Faculty of Sciences, Lorestan University, Khorramabad, Iran

2 Assistant Professor, Department of Geology, Faculty of Sciences, Lorestan University, Khorramabad, Iran

3 Associate Professor, Department of Geology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran

4 Associate Professor, Department of Geology, Faculty of Sciences, University of Zanjan, Zanjan, Iran

Abstract

Geysour area is located in the east of Gonabad city and is part of the north of the Lut Block. The rocks in this area include granitoid rocks and high temperature – low pressure metamorphic rocks. Granitoid rocks are composed of granodiorite, enclave (metamorphic and igneous) and microgranites. These rocks belong to medium to high potassium calc-alkaline series, low temperature I type granite and are poorly peraluminous. The Chondrite-normalized REE patterns show that the rocks are enriched incompatible elements, with negative anomalies in Nb, Ta, Sr, P, Ti and Ba and strong enrichment in Rb, K and Th. These patterns are in perfect harmony in granodiorite, microgranular enclave (MME) and microgranite specimens. This harmony also has in upper, middle continental crust and greywackes. Positive anomalies in Rb, Th, Sm and negative anomalies in Ba are prominent in the composition of the crust. Based on the integration of these patterns with the pattern of upper continental crust (UCC) elements and greywackes and adaptation to laboratory work, the Geysour granitoid originated from crustal materials and a little mantle component. The temperature of granitoid formation was estimated based on the Zircon saturation temperature of 748-790 ֯C. Microgranular enclaves have rounded and oval shapes, mixed areole around them, fine grained texture, quartz and plagioclase eyes, bladed biotite, needled apatite, oxide phases in biotite, and the presence of a simple mixed – hyperbolic curve between MME and granodiorite. Field, petrography and geochemistry of the major and rare earth elements data suggest mixing/ mingling (partial melting) processes for the origin of enclaves and the rare earth elements patterns indicates the relationship between Geysour granitoid with the subduction system. Analysing its data, based on logarithmic ratios, show collision tectonic environment. Also, the tectonic-chemical distinctive diagrams suggest a syn-collision to post-collision tectonic type that is interpreted in connection with the collision of the Afghan Block with the Lut Block.

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References
Anne, N. and Bouchez, J. L., 2011- Petrology, Structure, Geological setting and Mettallogeny. Oxford university press, 349p.
Arjmandzadeh, R., Karimpour, M. H., Mazaheri, S. A., Santos, J. F., Medina, J. M. and Homam, S. M., 2011- Two-sided asymmetric subduction; implications for tectonomagmatic and metallogenic evolution of the Lut Block, eastern Iran. Journal of Economic Geology, V. 3, p. 1-14.
B. R.G. M., 1992- Explanatory text of the Gonabad Quadrangle map 1:250000. Geological survey of Iran. p.166.
Barbarin, B. and Didier, J., 1992- Genesis and evolution of mafic microgranular enclaves through various types of interaction between coexisting felsic and mafic magmas. Earth and Environmental Science Transactions of the Royal Society of Edinburgh,  V. 83(1), p. 145- 153.
Barbarin, B., 2005- Mafic magmatic enclaves and mafic rocks associated with some granitoids of the central Sierra Nevada batholith, California: nature, origin and relations with the hosts. Lithos, V. 80, p. 155–177.
Berberian, M., 1983- Continental deformation on theIranian Plateau, G. S. I.. No. 52.
Boniface, N. and Mruma, A. H., 2012- Structural analysis, metamorphism, and geochemistry of the Archean granitoids-greenstones of the Sukumaland Greenstone Belt around Geita Hills, Northern Tanzania. Natural Science, V. 4(8), p. 526-535.
Bonin, B., 2007- A-type granites and related rocks: evolution of a concept, problems and prospects. Lithos, V. 97(1-2), p. 1-29.
Boynton, W. V., 1984- Geochemistry of the rare earth elements: meteorite studies. In: Henderson P.(ed.), Rare earth element geochemistry. Elsevier, p. 63-114.
Chappell, B. W. and White, A. J. R., 2001- Two contrasting granite types: 25 years later. Australian Journal of Earth Sciences, V. 48, p. 489–99.
Chappell, B. W., 1999- Aluminium saturation in I- and S-type granites and the characterization of fractionated haplogranites. Lithos V.46, P.535–551.
Chappell, B. W., White, A. J. R., Williams, I. S. and Wyborn, D., 2004- Low- and high-temperature granites. Transactions of the Royal Society of Edinburgh: Earth Sciences, V. 95, p. 125–140.
Chappell, B. W., White, A. J. R., Williams, I. S., Wyborn, D. and Wyborn, L.A.I., 2000- Lachlan Fold Belt granites revisited: high and low-temperature granites and their implications. Australian Journal of Earth Sciences, V. 47, p. 123–38.
Clarke, D. B., 1981- The mineralogy of peraluminous granites: a review. Canadian Mineralogist, V. 19, p. 3–17.
Collins, W. J., Beams, S. D., White, A. J. R. and Chappell, B. W. 1982- Nature and origin of A-type granites with particular reference to south-eastern Australia. Contributions to Mineralogy and Petrology, V. 80, p. 189–200.
DePaolo, D. J. and Farmer, G. L., 1984- Isotopic data bearing on the origin of Mesozoic and Tertiary granitic rocks in the western United States. Philosophical Transactions of the Royal Society A, V. 310, p. 743-753.
Didier, J. and Barbarin, B., 1991- The different types of enclaves in granites nomenclature. In: Didier, J., Barbarin, B. (Eds.), Enclaves and granite petrology: Developments in Petrology. Elsevier, p. 19–24.
Donaire, T., Pascual, E., Pin, C. and Duthou, J. L., 2005- Microgranular enclaves as evidence of rapid cooling in granitoid rocks: the case of the Los Pedroches granodiorite, Iberian Massif, Spain. Contributions to Mineralogy and Petrology, V. 149, p. 247–265.
Eby, G. N., 1990- The A-type granitoids: a review of their occurrence and chemical characteristics and speculations on their petrogenesis. Lithos, V. 26, p. 115-134.
Eftekharnejad, J., 1981- Tectonic division of Iran with respect to sedimentary basins. Journal of Iranian Petroleum Society, V. 82, p. 19–28 (in Persian).
Erkul, S. T. and Erkul, F., 2012- Magma interaction processes in syn-extensional granitoids: The Tertiary Menderes Metamorphic Core Complex, western Turkey. Lithos, V. 142-143, p. 16–33
Fang, Y., Zhang, Y. H., Zhang S. T., Cao, H.W., Zou, H. and Dong, J. H., 2018- Early Cretaceous I-type granites in the Tengchong terrane: New constraints on the late Mesozoic tectonic evolution of southwestern China. Geoscience Frontiers, V. 9, p. 459-470.
Fourcade, S. and Allegre, C. J., 1981- Trace Elements Behavior in Granite Genesis: A Case Study The Calc-Alkaline Plutonic Association from the Querigut Complex (Pyr6n6es, France). Contributions to Mineralogy and Petrology, V. 76, p. 177 1-95.
Gunter, F., 1977- Principles of isotope geology. Wiley International Edition, 589 p.
Hibbard, M. J., 1995- Petrography to Petrogenesis. Prentice Hall, Englewood Cliffs, New Jersey, p. 587.
Holden, P., Halliday, A. N., Stephens, W. E. and Henney, P. J., 1991- Chemical and isotopic evidence for major mass-transfer between mafic enclaves and felsic magma. Chemical Geology, V. 92, p. 135–152.
King, P. L., White, A. J. R., Chappell, B. W. and Allen, C. M., 1997- Characterization and origin of the aluminous A-type granites of the Lachlan Fold Belt, southeastern Australia. Journal of Petrology, V. 38, p. 371–91.
Kumar, S., Rino, V. and Pal, A. B., 2004- Field evidence of magma mixing from microgranular enclaves, central India. Gondwana Research, V. 7(2), p. 539-548.
Li, X. H., Li, W. X. and Li, Z. X., 2007- On the genetic classification and tectonic implications of the Early Yanshanian granitoids in the Nanling Range, South China. Chinese Science Bulletin V. 52, p.1873–1885.
McDonough, W. F., Sun, S., Ringwood, A. E., Jagoutz, E. and Hofmann, A. W., 1991- K, Rb and Cs in the earth and moon and the evolution of the earth ’s mantle. Cosmochimca et Cosmochemica Acta, V. 56, p. 1001-1012.
Middlemost, E. A.1989- Iron Oxidation Ratios, Norms and the Classification of Volcanic Rocks. Chemical Geology, V. 77, p. 19-26.
Moine, B., Ramambazafy, A., Rakotondrazafy, M., Ravolomiandrinarivo, B., Cuney, M. and de Parseval, P., 1998- The role of flour-rich fluids in the formation of the thorianite and sapphire deposits from SE Madagascar. Goldschmidt Conference Toulouse.
Nabavi, M. H., 1976- An introduction to the geology of Iran. Geological Survey of Iran. 109 p.
Nelson, S. T. and Montana, A., 1992- Sieve-textured plagioclase in volcanic rocks produced by rapid decompression. American Mineralogist, V. 77, p. 1242-1249.
Patin˜o Douce, A. E. and Beard, J. S., 1995- Dehydration-melting of biotite gneiss and quartz amphibolite from 3 to 15 kbar. Journal of Petrology, V. 36, p. 707–738.
Patin˜o Douce, A. E. and Beard, J. S., 1996- Effects of P, f_O2. and Mg/Fe ratio on dehydration melting of model metagreywackes. Journal of Petrology, V. 37, p. 999–1024.
Patin˜o Douce, A. E. and McCarthy, T. C., 1998- Melting of crustal rocks during continental collision and subduction. In: Hacker, B.R., Liou, J.G. -Eds.., When Continents Collide: Geodynamics and Geochemistry of Ultrahigh-Pressure Rocks. Petrology and Structural Geology, Vol. 10. Kluwer Academic Publishers, Dordrecht, p. 27–55.
Patin˜o Douce, A. E., 1996- Effects of pressure and H2O content on the composition of primary crustal melts. Transactions of the Royal Society of Edinburgh: Earth Science, V. 87, p. 11–21.
Pearce, J. A., 1996- Sources and settings of granitic rocks. Episodes, V. 4, p. 120-125.
Pearce, J. A., Harris, N. B.W. and Tindle, A. G., 1984- Trace element discrimination diagrams for the Tectonic interpretation of granitic rocks. Journal of Petrology, V. 4, p. 956-983.
Qiu, J. T., Song, W. J., Jiang, C. X.; Wu, H. D. and Raymond, M., 2013- CGDK: An extensible CorelDRAW VBA program for geological drafting. Computers and Geosciences, V. 51, p. 34-48.
Rapp, R. P. and Watson, E. B., 1995- Dehydration melting of metabasalt at 8–32 kbar: implications for continental growth and crust–mantle recycling. Journal of Petrology, v. 36, p. 891–931.
Roberts, M. P. and Clemens, J. D., 1993- Origin of high-potassium, calc-alkaline, I-type granitoids. Geology, V. 21, p. 825–828.
Rollinson, H., 2002- Using geochemical data evaluation, presentation, interpretation. Pearson Education Limited, 380p.
Rudnick, R. L. and Gao, S., 2003- Composition of the continental crust. In: Rudnick, R.L. (Ed.), The Crust. Elsevier, p. 1–64.
Saccani, E., Delavari, M., Beccaluva, L. and Amini, S. A., 2010- Petrological and geochemical constraints on the origin of the Nehbandan ophiolitic complex (eastern Iran): Implication for the evolution of the Sistan Ocean. Lithos, V. 117(1-4), p. 209-228.
Samani, B. and Ashtari, Sh., 1992- Geological evolution of Sistan and Baluchestan area. Journal of earth sciences. Geological Survey of Iran. No4.
Shand, S. J., 1949- Eruptive Rocks. New York: Jone wiley and Sons, 488p.
Shelley, D., 1992- Igneous and metamorphic rocks under the Microscope. Classification, Textures, Microstructures and Mineral Preferred Orientations. London (Chapman and Hall), 445p.
Silva, M. M. V. G., Neiva, A. M. R. and Whitehouse, M. J., 2000- Geochemistry of enclaves and host granites from the Nelas area, central Portugal. Lithos, V. 50, p. 153-170 .
Tindle, A. G. and Pearce, J. A., 1983- Assimilation and partial melting of continental crust: evidence from the mineralogy and geochemistry of autholiths and xenoliths. Lithos, V. 16, p. 185-202.
Verma, S. P., Pandarinath, K., Verma, S. K. and Agrawal, S., 2013- Fifteen new discriminant-function-based multi-dimensional robust diagrams for acid rocks and their application to Precambrian rocks. Lithos, V. 168, p. 113–123.
Vidal, Ph., Cocherie, A. and Le Fort, P., 1982- Geochemical investigations of the origin of the Manaslu leucogranite (Himalaya, Nepal). Geochimica et Casmochimica Acta, V. 46, p. 2279-2292.
Vogel, T. A., 1982- Magma mixing in the acidic–basic complex of Ardnamurchan: implications on the evolution of shallow magma chambers. Contributions to Mineralogy and Petrology, V. 79, p. 411-423.
Waight, T. E., Maas, R. and Nicholls, I.A., 2001- Geochemical investigations of microgranitoid enclaves in the S-type Cowra Granodiorite, Lachlan Fold Belt, SE Australia. Lithos, V. 56, p. 165–186.
Watson, E. B. and Harrison, T. M., 1983- Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types. Earth and Planetary Science Letters, V. 64, p. 295–304.
Whalen, J.B., Currie, K.L. and Chappell, B.W., 1987- A-Type Granites - Geochemical Characteristics, Discrimination and Petrogenesis. Contributions to Mineralogy and Petrology, V. 95(4), p.407-419.
White, A. J. R. and Chappell, B.W., 2004- Petrographic discrimination of low- and high temperature I-type granites. Resource Geology, V. 54, p. 215–226.
Wilson, M., 2007- Igneous Petrogenesis—A Global Tectonic Approach. Published by Springer, 480p.
Zen, E-an, 1986- Aluminum enrichment in silicate melts by fractional crystallization: some mineralogic and petrographic constraints. Journal of Petrology, V. 27, p. 1095–1117.