Mineralogy, geochemistry and geotectonic of plagiogranites from Shahre-Babak ophiolite, Zagros zone, Iran

Abstract

Shahre-Babak ophiolite is a part of the inner Zagros ophiolite belt in Iran. Major parts of intrusive masses of Share-Babak ophiolite are gabbro and plagiogranite. The SiO₂ versus Na₂O+K₂O diagram shows that the palgiogranites are related to calk-alkaline series. Rare earth elements exhibit relatively similar pattern that indicates these rocks are syngenetic. Also, REE patterns display an enrichment of LREE compared to HREE, and are characterized by flat to slightly concaveup patterns from Gd to Yb. Such patterns contrast sharply with those of plagiogranites in more complete ophiolite sequences, such as the Semail ophiolite, Oman, or the Troodos ophiolite, Cyprus, and Neyriz, where patterns are much flatter and slightly LREE-depleted. The slightly LREE-enriched patterns of the Shahre-Babak plagiogranites support a partial melting origin for them. The low TiO₂, Nb, Ta content and high LREE concentrations of the Shahre-Babak plagiogranites indicate that the rocks were likely derived from the anatexis of amphibolites, which were related to hydrothermal alteration of gabbros in intra-oceanic back-arc basin.

Keywords

plagiogranite / back-arc basin / Share-Babak ophiolite / Neo-Tethys / Iran

References

Ahmadipour H., Rostamizadeh G. Geochemical Aspects of Na-Metasomatism in Sargaz Granitic Intrusion (South of Kerman Province, Iran).. Journal of Sciences, Islamic Republic of Iran, 2012, 23: 45-58.

Alavi M., Vaziri H., Seyed-Emami K., . The Triassic and Associated Rocks of the Nakhlak and Aghdarband Areas in Central and Northeastern Iran as Remnants of the Southern Turanian Active Continental Margin.. Geological Society of America Bulletin, 1997, 109(12): 1563-1575.

Aldiss D. T. Plagiogranites from the Ocean Crust and Ophiolites.. Nature, 1981, 289(5798): 577-578.

Alizadeh E., Arvin M., Dargahi S. Geochemistry and Petrogenesis of Plagiogranites in the Neyriz Ophiolitic Sequence, Iran: Constraints on Their Origin.. Journal of Petrology, 2012, 12: 1-14.

Allègre C. J., Minster J. F. Quantitative Models of Trace Element Behavior in Magmatic Processes.. Earth and Planetary Science Letters, 1978, 38(1): 1-25.

Arth J. G. Behavior of Trace Elements during Magmatic Processes––A Summary of Theoretical Models and Their Applications. J. Res. US Geol. Surv., 1976, 4: 41-47.

Babaie H. A., Babaei A., Ghazi A. M., . Geochemical, ⁴⁰Ar/³⁹Ar Age, and Isotopic Data for Crustal Rocks of the Neyriz Ophiolite, Iran.. Canadian Journal of Earth Sciences, 2006, 43(1): 57-70.

Bedard J. H. Petrogenesis of Boninites from the Betts Cove Ophiolite, Newfoundland, Canada: Identification of Subducted Source Components.. Journal of Petrology, 1999, 40(12): 1853-1889.

Berberian M., King G. C. P. Towards a Paleogeography and Tectonic Evolution of Iran.. Canadian Journal of Earth Sciences, 1981, 18(2): 210-265.

Berndt J., Koepke J., Holtz F. An Experimental Investigation of the Influence of Water and Oxygen Fugacity on Differentiation of MORB at 200 MPa.. Journal of Petrology, 2005, 46(1): 135-167.

Bézos A., Humler E. The Fe³⁺/ƩFe Ratios of MORB Glasses and Their Implications for Mantle Melting.. Geochimica et Cosmochimica Acta, 2005, 69(3): 711-725.

Boomeri M., Mizuta T., Ishiyama D., . Fluorine and Chlorine in Biotite from the Sarnwosar Granitic Rocks, Northeastern Iran.. Iranian Journal of Science & Technology, Transaction A, 2006, 30(A1): 111-125.

Boynton W. V. Henderson P. Cosmochemistry of the Rare Earth Elements: Meteorite Studies. Rare Earth Element Geochemistry, 1984 Amsterdam: Elsevier, 63-114.

Christie D. M., Carmichael I. S. E., Langmuir C. H. Oxidation States of Mid-Ocean Ridge Basalt Glasses.. Earth and Planetary Science Letters, 1986, 79(3/4): 397-411.

Coleman R. G., Donato M. Oceanic Plagiogranite Revisited. Trondhjemites, Dacites, and Related Rocks, 1979 Amsterdam: Elsevier, 149-167.

Coleman R. G., Peterman Z. E. Oceanic Plagiogranite.. Journal of Geophysical Research, 1975, 80(8): 1099-1108.

Dilek Y., Furnes H. Ophiolite Genesis and Global Tectonics: Geochemical and Tectonic Fingerprinting of Ancient Oceanic Lithosphere.. Geological Society of America Bulletin, 2011, 123(3/4): 387-411.

Dixon S., Rutherford M. J. Plagiogranites as Late-Stage Immiscible Liquids in Ophiolite and Mid-Ocean Ridge Suites: An Experimental Study.. Earth and Planetary Science Letters, 1979, 45(1): 45-60.

Flagler P. A., Spray J. G. Generation of Plagiogranite by Amphibolite Anatexis in Oceanic Shear Zones.. Geology, 1991, 19(1): 70-73.

Floyd P. A., Yaliniz M. K., Goncuoglu M. C. Geochemistry and Petrogenesis of Intrusive and Extrusive Ophiolitic Plagiogranites, Central Anatolian Crystalline Complex, Turkey.. Lithos, 1998, 42(3/4): 225-241.

Frost B. R., Barnes C. G., Collins W. J., . A Geochemical Classification for Granitic Rocks.. Journal of Petrology, 2001, 42(11): 2033-2048.

Gerlach D. C., Leeman W. P., Lallemant H. G. A. Petrology and Geochemistry of Plagiogranite in the Canyon Mountain Ophiolite, Oregon.. Contributions to Mineralogy and Petrology, 1981, 77(1): 82-92.

Ghazi A. M., Hassanipak A. A. Petrology and Geochemistry of the Shahr-Babak Ophiolite, Central Iran.. Geological Society of America Bulletin, Special Paper, 2000, 349: 485-497.

Golestani M. Petrology, Geochemistry and Tectonic Setting Intrusive Massives of Baft Ophiolitic––Melange, Southeast of Kerman, Iran.. Journal of Tethys, 2013, 3: 164-176.

Grimes C. B., John B. E., Cheadle M. J., . Protracted Construction of Gabbroic Crust at a Slow Spreading Ridge: Constraints from ²⁰⁶Pb/²³⁸U Zircon Ages from Atlantis Massif and IODP Hole U1309D (30ºN, MAR).. Geochemistry, Geophysics, Geosystems, 2008, 9(8): 1-24.

Grimes C. B., Ushikubo T., Kozdon R., . Perspectives on the Origin of Plagiogranite in Ophiolites from Oxygen Isotopes in Zircon.. Lithos, 2013, 179: 48-66.

Hanson G. N. The Application of Trace Elements to the Petrogenesis of Igneous Rocks of Granitic Composition.. Earth and Planetary Science Letters, 1978, 38(1): 26-43.

Hawkesworth C. J., Gallagher K., Hergt J. M., . Mantle and Slab Contributions in ARC Magmas.. Annual Review of Earth and Planetary Sciences, 1993, 21(1): 175-204.

Humphris S. E. Henderson P. The Mobility of the Rare Earth Elements in the Crust. Rare Earth Element Geochemistry, 1984 Amsterdam: Elsevier, 317-342.

Jiang Y. H., Liao S. Y., Yang W. Z., . An Island Arc Origin of Plagiogranites at Oytag, Western Kunlun Orogen, Northwest China: SHRIMP Zircon U-Pb Chronology, Elemental and Sr-Nd-Hf Isotopic Geochemistry and Paleozoic Tectonic Implications.. Lithos, 2008, 106(3/4): 323-335.

Koepke J., Berndt J., Feig S. T., . The Formation of SiO₂-Rich Melts within the Deep Oceanic Crust by Hydrous Partial Melting of Gabbros. Contrib. Miner.. Petrol., 2007, 153: 67-84.

Koepke J., Feig S. T., Snow J., . Petrogenesis of Oceanic Plagiogranites by Partial Melting of Gabbros: An Experimental Study.. Contributions to Mineralogy and Petrology, 2004, 146(4): 414-432.

Li X. H., Faure M., Lin W., . New Isotopic Constraints on Age and Magma Genesis of an Embryonic Oceanic Crust: The Chenaillet Ophiolite in the Western Alps.. Lithos, 2013, 160/161: 283-291.

Lippard S. J., Shelton A. W., Gass I. G. The Ophiolite of Northern Oman. Geological Society of London Memoir.. Blackwell Scientific Publications, Oxford., 1986, 11 178.

Ludden J. N., Thompson G. An Evaluation of the Behavior of the Rare Earth Elements during the Weathering of Sea-Floor Basalt.. Earth and Planetary Science Letters, 1979, 43(1): 85-92.

Malpas J. Two Contrasting Trondhjemite Associations from Transported Ophiolites in Western Newfoundland: Initial Report.. Developments in Petrology, 1979, 9: 465-487.

Martin H., Smithies R. H., Rapp R., . An Overview of Adakite, Tonalite-Trondhjemite-Granodiorite (TTG), and Sanukitoid: Relationships and Some Implications for Crustal Evolution.. Lithos, 2005, 79(1/2): 1-24.

Meffre S., Aitchison J. C., Crawford A. J. Geochemical Evolution and Tectonic Significance of Boninites and Tholeiites from the Koh Ophiolite, New Caledonia.. Tectonics, 1996, 15(1): 67-83.

Mirnejad H., Lalonde A. E., Obbeid M., . Geochemistry and Petrogenesis of Mashhad Granitoid: An Insight into the Geodynamic History of Paleo-Tethys in Northeast of Iran.. Lithos, 2013, 170: 105-116.

Nakamura N. Determination of REE, Ba, Fe, Mg, Na and K in Carbonaceous and Ordinary Chondrites.. Geochimica et Cosmochimica Acta, 1974, 38(5): 757-775.

O’Connor J. T. A Classification for Quartz-Rich Igneous Rock Based upon Feldspar Ratios. U.S.G.S.. Professional Paper, 1965, 525B: B79-B84.

Pearce J. A. Hawkesworth C. J., Norry M. J. Role of the Sub-Continental Lithospher in Magma Genesis at Active Continental Margin. Continental Basalts and and Mantle Xenolitehs, 1983, 230-249.

Pearce J. A., Norry M. J. Petrogenetic Implications of Ti, Zr, Y, and Nb Variations in Volcanic Rocks.. Contributions to Mineralogy and Petrology, 1979, 69(1): 33-47.

Pedersen R. B., Malpas J. The Origin of Oceanic Plagiogranites from the Karmoy Ophiolite, Western Norway.. Contributions to Mineralogy and Petrology, 1984, 88(1/2): 36-52.

Rajabzadeh M. A., Dehkordi T. N., Caran S. Mineralogy, Geochemistry and Geotectonic Significance of Mantle Peridotites with High-Cr Chromitites in the Neyriz Ophiolite from the Outer Zagros Ophiolite Belts, Iran.. Journal of African Earth Sciences, 2013, 78: 1-15.

Shafaii Moghadam H., Stern R. J., Chiaradia M., . Geochemistry and Tectonic Evolution of the Late Cretaceous Gogher-Baft Ophiolite, Central Iran.. Lithos, 2013, 168–169: 33-47.

Shafaii Moghadam H., Whitechurch H., Rahgoshay M., . Significance of Nain-Baft Ophiolitic Belt (Iran): Short-Lived, Transtensional Cretaceous Back-Arc Oceanic Basins over the Tethyan Subduction Zone.. Comptes Rendus Geoscience, 2009, 341(12): 1016-1028.

Snyder D., Carmichael I. S. E., Wiebe R. A. Experimental Study of Liquid Evolution in an Fe-Rich, Layered Mafic Intrusion: Constraints of Fe-Ti Oxide Precipitation on the T-f _O2 and T-_Q Paths of Tholeiitic Magmas.. Contributions to Mineralogy and Petrology, 1993, 113(1): 73-86.

Tilton G. R., Hopson C. A., Wright J. E. Uranium-Lead Isotopic Ages of the Samail Ophiolite, Oman, with Applications to Tethyan Ocean Ridge Tectonics.. Journal of Geophysical Research: Solid Earth, 1981, 86(B4): 2763-2775.

Toplis M. J., Carroll M. R. An Experimental Study of the Influence of Oxygen Fugacity on Fe-Ti Oxide Stability, Phase Relations, and Mineral––Melt Equilibria in Ferro-Basaltic Systems.. Journal of Petrology, 1995, 36(5): 1137-1170.

Walker R., Jackson J. Offset and Evolution of the Gowk Fault, S.E. Iran: A Major Intra-Continental Strike-Slip System.. Journal of Structural Geology, 2002, 24(11): 1677-1698.

Walker R., Jackson J. Offset and Evolution of the Gowk Fault, S.E. Iran: A Major Intra-Continental Strike-Slip System.. Journal of Structural Geology, 2002, 24(11): 1677-1698.

Xu J. F., Castillo P. R., Chen F. R., . Geochemistry of Late Paleozoic Mafic Igneous Rocks from the Kuerti Area, Xinjiang, Northwest China: Implications for Backarc Mantle Evolution.. Chemical Geology, 2003, 193(1/2): 137-154.

Zeng L. J., Niu H. C., Bao Z. W., . Petrogenesis and Tectonic Significance of the Plagiogranites in the Zhaheba Ophiolite, Eastern Junggar Orogen, Xinjiang, China.. Journal of Asian Earth Sciences, 2015, 113: 137-150.