MESOZOIC BACK-ARC EXTENSION IN THE ACTIVE MARGIN OF THE IRANIAN CONTINENTAL BLOCK: CONSTRAINTS FROM AGE AND GEOCHEMISTRY OF THE MAFIC LAVAS

Authors

  • Hadi Shafaii Moghadam Damghan University of Basic Sciences, School of Earth Sciences, Damghan, Iran
  • Mohamad Rahgoshay Shahid Beheshti University, Faculty of Earth Sciences, Tehran, Iran
  • Hubert Whitechurch Ecole et Observatoire des Sciences de la Terre, Institute de Physique du Globe, Strasbourg, France

DOI:

https://doi.org/10.4454/ofioliti.v33i2.362

Keywords:

Abstract

The Nain-Baft ophiolitic suture, along the active margin of the Central Iranian continental block (the Sanandaj-Sirjan zone) features back-arc extension during the Late Mesozoic. This ophiolitic belt is characterized by occurrence of mafic lavas including pillow lavas, diabasic dikes and layers, massive basaltic lavas and basaltic-andesitic rock fragments in the volcanic breccias. These mafic lavas display both calc-alkaline and island-arc tholeiitic affinities with enrichment in LILE and depletion in HFSE. Conventional K-Ar measurements on amphibole indicate the Middle Cretaceous for the creation and evolution of the Nain-Baft back-arc basins. As a result of oblique subduction of the Tethyan Ocean, a narrow transtensional back-arc basin could start to open along large transcurrent faults in the active margin of the Iranian continental block.

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Published

2008-07-01

How to Cite

Moghadam, H. S., Rahgoshay, M., & Whitechurch, H. (2008). MESOZOIC BACK-ARC EXTENSION IN THE ACTIVE MARGIN OF THE IRANIAN CONTINENTAL BLOCK: CONSTRAINTS FROM AGE AND GEOCHEMISTRY OF THE MAFIC LAVAS. Ofioliti, 33(2), 95-103. https://doi.org/10.4454/ofioliti.v33i2.362

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Articles