Tectonic setting and geochronology of the Cadomian (Ediacaran-Cambrian) magmatism in Central Iran, Kuh-e-Sarhangi region (NW Lut Block). (15th April 2015)

• Record Type: Journal Article
• Authors: Rossetti, Federico; Nozaem, Reza; Lucci, Federico; Vignaroli, Gianluca; Gerdes, Axel; Nasrabadi, Mohsen; Theye, Thomas
• Is Part Of: Journal of Asian earth sciences. Volume 102(2015)
• Page Start: 24
• Page End: 44
• Publication Date: 2015-04-15
• Subjects: Arc magmatism -- Transpressional orogens -- Cadomian -- Gondwana assembly -- Lut Block -- Iran; Earth sciences -- Asia -- Periodicals; Sciences de la terre -- Asie -- Périodiques; Earth sciences; Asia; Periodicals; 555.05
• DOI: 10.1016/j.jseaes.2014.07.034
• Languages: English
• ISSNs: 1367-9120

Abstract

Highlights: Cadomian (Ediacaran-Cambrian) tranpressional tectonics and pluton emplacement in Central Iran. The exhumed roots of the Cadomian magmatic arc are exposed in Central Iran. An oblique subduction setting for the terminal assembly of northern Gondwana. Abstract: The structure, age and petrogenesis of plutonic basement rocks from the Kuh-e-Sarhangi region, located in the Kashmar-Kerman tectonic zone of Central Iran are described. These intrusive rocks consist of a sub-alkaline, dominantly high-K calc-alkaline acidic suite, characterised by high SiO2 (72.60–77.17 wt%), and alkalis (up to 8 wt%) and low Mg# (07-35). They are also enriched in Th, U and light rare earth elements, and depleted in Nb, Ta, and Ti, thus showing a geochemical fingerprint compatible with arc magmatism. The U–Pb zircon geochronology constrains magma crystallisation and emplacement during Ediacaran-Cambrian (ca. 575–535 Ma) times, under a tectonic regime dominated by transpressional tectonics as constrained by analysis of field structures. Combined inverse and forward modelling thermobarometry indicates pluton emplacement occurred in a thickened crustal environment, suggesting the Kuh-e-Sarhangi magmatic belt exposes the exhumed roots of a volcanic arc. This magmatism is interpreted as part of the Cadomian, subduction-related magmatism and framed within an oblique convergence scenario during formation of an Andean-type active margin all along the northern (proto-Tethyan) margin of the Gondwana Supercontinent.