Evidences for formation of the Precambrian crust in the Takab complex, northwest Iran (review)

The Takab Precambrian rocks with a variety of metamorphic and igneous rocks including pelitic schists, gneiss, meta-ultramafic, amphibolites, calc-silicate and granitoids crop out in the northwest of Iran. In the context of the structural subdivisions of Iran, the Takab Complex has been assigned to the Central Iran Zones; it seems to have more affinities to this zone from the viewpoint of stratigraphy, lithology and age data. P-T conditions of metapelitic and meta-ultramafic rocks attributed to the most orogenic belts, in the other hand geochemical studies of metapelitic and gneiss protolith is related to magmatic arc tectonic setting. All these characteristics and the presence of paleo-suture zones and ophiolitic rocks around the high grade metamorphic rocks suggest an island-arc type cratonization formed the Takab Precambrian basement. This complex belonged to a greater late Neoproterozoic-early Paleozoic orogenic system that was active along the Proto-Tethyan margin of the Gondwanaland supercontinent, extending at least from its Arabian margin to the Himalayan margin of the Indian subcontinent.