Mineral chemistry and petrogenesis of metabasites of metamorphic - igneous Shotor-Kuh complex (SE Shahrood) an indicator for evolution of  intracontinental extensional basins of late Neoproterozoic

Shekari, S.; Sadeghian, M.; Zhai, M.; Ghasemi, H.; Zou, Y.

doi:10.22071/gsj.2017.54181

Document Type : Original Research Paper

Authors

¹ Ph.D. Student, Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology, Shahrood, Iran

² Assocciated Professor, Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology, Shahrood, Iran

³ Professor, Institute of Geology and Geophysics, Chinese Academy of Science, Beijing; Northwest University, Xian, China

⁴ Professor, Department of Petrology and Economic Geology, Faculty of Earth Sciences, Shahrood University of Technology, Shahrood, Iran

⁵ Ph.D Student, Institute of Geology and Geophysics, Chinese Academy of Science, Beijing, China

https://doi.org/10.22071/gsj.2017.54181

Abstract

Metamorphic - igneous Shotor-Kuh complex is located in the 80 km of SE Shahrood and in the northern edge of the central Iran structural zone. This complex includes a wide lithological composition range such as metapelite (micaschists and gneisses), metapsammites, metabasites (amphibolite and garnet amphibolite), metacarbonate (limestone and dolomitic marbles) and metrhyolites. Protolith of metabasites have been basaltic lavas, diabasic swarm dikes and small scale gabbro-dioritic intrusions. With respect to abundance and importance of metamorphosed basaltic intercalations and diabasic swarm dikes in comparison to the other basic rocks, this article specially advocated to investigation of their evolution. Based on the field evidence and petrography, increasing the degree of metamorphism of metabasites resulted in producing of amphibole schist, amphibolite, garnet amphibolite and eventually amphibolitic migmatites. Thermobarometery based on the chemical analysis of garnet, amphibole and plagioclase of the metabasites indicates that the thermal range of 602-711 °C and 9-11 Kbar pressure for their formation, stop of exchange and final equilibrium, which accommodate with P-T condition of amphibolite and upper amphibolites facies. From the geochemical points of view, the magmas forming of these metabasites have tholeitic to calc-alkaline nature. These magmas originated from the subcontinental lithospheric mantel source. Submarine basaltic lava flows and diabasic swarm dikes originated during extensional tectonic regimes which affected Late Neoproterozoic Iranian Gondwanan terrains. These extensional tectonic regimes are associated with producing of intracontinental sea to oceanic basins (riffitic or back arc). The mentioned basins closed in a short time and lead to generate tectonic melange or accretionary prisms on the continental crust. Based on the U- Pb age dating of the Zircons extracted from these metasbasites, these metamorphism event occurred in the interval time of 526-577 Million years (corresponds to the late Neoproterozoic and Cadomian orogeny in the Iranian Gondwanan landforms).

Keywords

20.1001.1.10237429.1396.27.105.17.0

References

References

Anderson, J. L., 1996- Status of thermobarometery in granitic batholiths: Transactions of the Royal Society of Edinburgh, v. 87, 125-138. [Also published in GSA Special Paper 315]

Balaghi, Z., Sadeghian, M., Ghasemi, H., Zhai, M. G. and Mohajjel, M., 2014- Zircon U–Pb ages, Hf isotopes and geochemistry of the schists, gneisses and granites in Delbar Metamorphic-Igneous Complex, SE of Shahrood (Iran): implications for Neoproterozoic geodynamic evolutions of central Iran, Journal of Asian Earth Sciences 92, 92–124.

Best, M. G., 2003- Igneous and metamorphic petrology, Blackwell Science Ltd, 758 pp.

Bucher, K. and Grapes R., 2011- Petrogenesis of Metamorphic Rocks. Springer-Verlag Berlin Heidelberg, 428 pp.

Coban, H., 2007- Basalt magma genesis and fractionation in collision-and extension-related provinces: A comparison between eastern, central and western Anatolia. Earth-Science Reviews 80, 219-238.

Davies, J. F., Grant, R. W. E. and Whitehead, R. E. S., 1979- Immobile trace elements and Archean volcanic stratigraphy in the Timmins mining area, Ontario. Canadian, Journal of Earth Science. 16, 305–311.

Deer, W. A., Howie, R. A. and Zussman, J., 1992- An introduction to the rock forming minerals, Longman Ltd, 528 pp.

Droop, G. T. R., 1987- A general equation for estimating Fe³⁺ concentration in ferromagnesian silicates and oxides from microprobe analysis, using stoichiometric criteria, Mineralogical Magazine 51: 431-435.

Ellam, R. M. and Cox, K, G., 1991- An interpretation of Karoo picrate basalts in terms of interaction between asthenospheric magmas and the mantle lithosphere. Earth Plan SciLett. 105, pp. 330 – 342.

Graham, C. M. and Powell, R., 1984- A garnet–hornblende geothermometer: calibration, testing, and application to the Pelona Schist, Southern California. Journal of Metamorphic Geology 3, 13–21.

Hammarastrom, J. M. and Zen, E. A., 1986- Aluminum in hornblende: An empirical igneous geobarometer. American mineralogist 71, 1297-1313.

Hassanzadeh, J., Stockli, D., Horton, B., Axen, G., Stockli, L., Grove, M,. Schmditt, A. and Walker, D., 2008- U-Pb zircon geochronology of late Neoproterozoic – Early Cambrian granitoids in Iran: Implications for paleogeography, magmatism, and exhumation history of Iranian basement, 2008. Tectonophysics 451, 71- 96.

Hollister, L. S., Grissom, G. E., Peters, E. K., Stowell, H. H., and Sisson, V. R. 1987- Confirmation of the empirical correlation of Al in hornblende with pressure of solidification of calc-alkaline plutons". American Mineralogist 72, 231-239.

Hosseini, S. H., Sadeghian, M., Zhai, M., Ghasemi, H., 2015- Petrology, geochemistry and zircon U–Pb dating of Band-e-Hezarchah metabasites (NE Iran): An evidence for back-arc magmatism along the northern active margin of Gondwana, Chemie der Erde 75, 207–218.

Johnson, M. C. and Rutherford, M. J., 1989- Experimental calibration of the aluminum-inhornblende geobarometer with application to Long Valley caldera (California). Geology 17, 837-841.

Kohn, M. J. and Spear, F. S., 1990- Two new geobarometers for garnet amphibolites, with applications to southeastern Vermont. American Mineralogist 75, 89-96.

Leake, B. E., 1965- The relationship between tetrahedral aluminum and the maximum possible octahedral aluminum in natural calciferous and subcalciferous amphiboles, American Mineralogist, 50: 843 - 851.

Leake, B. E., Woolley, A. R., Arps, C. E. S., Birch, W. D., Gilbert, M. C., Grice, J. D., Hawthorne, F. C., Kato, A., Kisch, H. J., Krivovichev, V. G., Linthout, K., Laird, J., Mandarino, J. A., Maresch, W. V., Nickel, E. H., Rock, N. M. S., Schumacher, J. C., Smith, D. C., Stephenson, N. C. N., Ungaretti, L., Whittaker, E. J. W. and Youzhi, G., 1997- Nomenclature of amphiboles: report of the subcommittee on amphiboles of the International Mineralogical Association, Commission on new minerals and mineral names. Canadian Mineralogist 35, 219- 246.

Leake, R. E., 1978- Nomenclature of amphiboles. Canadian Mineralogist 16, 501-520.

Middlemost, E. A. K., 1975- The basalt clan. Earth Sci. Rev, 11, 337-364.

Middlemost, E. A. K., 1985- Magma and magmatic rocks, an introduction to igneous petrology. Longman Group U.K, 73-86.

Misra, S. N., 1971- Chemical distinction of high-grade ortho- and para-metabasites. Norsk Geologisk Tidsskrift 51, 311–316.

Pearce, J. A., 1983- Role of the sub-continental lithosphere in magma genesis at active continental margin. In: C. J., Hawkesworth and M. J., Norry (Eds.): Continental Basalts and Mantle Xenoliths. Shiva, Nantwich, 230–249.

Pearce, J. A., 1996- A User's guide to basalt discrimination diagrams. In: Wyman, D. A. (eds.) Trace Element Geochemistry of Volcanic Rocks: Applications for Massive Sulphide Exploration", Geological Association of Canada 12, 79- 113.

Pearce, J. A., 2008- Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust, Lithos 100, 14–48.

Perchuk, L. L. and Lavrent'eva, I. V., 1990- Garnetorthopyroxene and garnet-amphibole geothermobarometry. International Geological Review 32, 486-507.

Rahmati-Ilkhchi, M., Faryad, S. W., Holub, F. V., Koˇsler, J. and Frank, W., 2011- Magmatic and metamorphic evolution of the Shotur Kuh metamorphic complex (central Iran). Int. J. Earth. Sci. 100: 45–62.

Rahmati-Ilkhchi, M., Jera´bek P., Faryad, S. W. and Kosler J., 2008- Tectonometamorphic evolution of the Shotur Kuh metamorphic core complex in the Central Iranian block. In: 6th Meeting of the Central European Tectonic Group, Upohlav Slovakia Slov Tec, 08, 48–49.

Rahmati-Ilkhchi, M., Jerabek, P., Faryad, S. W. and Koyi, H. A., 2010- Mid-Cimmerian, Early Alpine and Late Cenozoic orogenic events in the Shotor Kuh Metamorphic complex, Great Kavir Block, NE Iran. Tectonophysics 494: 101 - 117.

Schmidt, M. W., 1992- Amphibole composition in tonalite as a function of pressure: An experimental calibration of the AI-in-hornblende barometer. Contributions to Mineralogy and Petrology 110, 304-310.

Stein, E. and Dietl, C., 2001- Hornblende thermobarometery of granitoids from the Central Odenwald (Germany) and their implications for the geotectonic development of the Odenwald, Mineralogy and Petrology 72, 185–207.

Sun, S. S. and McDonough, W. F., 1989- Chemical and isotopic systematics of oceanic basalt: implications for mantle composition and processes. In: Sanders, A.D., Norry, M.J. (Eds.), Magmatism in the Ocean Basins: Geological Society Special Publication, 42, 528–548.

Walker, K. R., Joplin, G. A., Levering, J. F. and Green, R., 1960- Metamorphic and metasomatic convergence of basic igneous rocks and lime-magnesia sediments of the precambrian of northwestern Queensland. 3. Geol. Soc. Australia 6, 149-177.

Winter, J. D., 2001- An introduction to igneous and metamorphic petrology. Prentice Hall, New Jersey, 697 pp

Scientific Quarterly Journal of Geosciences

Mineral chemistry and petrogenesis of metabasites of metamorphic - igneous Shotor-Kuh complex (SE Shahrood) an indicator for evolution of intracontinental extensional basins of late Neoproterozoic

References

References

Volume 27, Issue 105
December 2017
Pages 167-182

Mineral chemistry and petrogenesis of metabasites of metamorphic - igneous Shotor-Kuh complex (SE Shahrood) an indicator for evolution of intracontinental extensional basins of late Neoproterozoic

References

References

Volume 27, Issue 105December 2017Pages 167-182

Volume 27, Issue 105
December 2017
Pages 167-182