Basic volcanic rocks from the West Nain area of the Urumieh–Dokhtar Magmatic Assemblage demonstrate significant subduction-related geochemical characteristics; these along with the new age data obtained for the volcanic rocks shed new light on the geodynamic evolution of the Iranian segment of Alpine–Himalayan orogeny. The late Oligocene (26.5 Ma) high-Nb basic volcanic rocks are likely to represent a transient rather enriched asthenospheric mantle underlying the otherwise dominantly Eocene–early Oligocene West Nain island arc. Lithospheric mantle geochemical signatures of the low-Zr volcanic rocks (20.6 Ma) and high-Th volcanic rocks (19.7 Ma) imply replacement of the underlying mantle. The substitution of asthenospheric mantle by a lithospheric mantle wedge might have been associated with – or perhaps caused by – an increase in the subduction rate. Culmination of the West Nain magmatism into slab melting that produced the early Miocene (18.7 Ma) adakitic rocks is compatible with subsequent ascent that triggered slab decompression melting.

More than 200 iron deposits with about 4 billion tons of iron ore have been discovered in Iran. Major iron oxide districts comprise the Bafq-Posht-e-Badam back arc district in Central Iranian microcontinent, the Ac Kahoor and Hormoz districts in the Zagros mountain range, the Gol-e-Gohar and Hamekasi deposits in the Sanandaj–Sirjan magmatic–metamorphic zone and also the Sangan deposit east of Central Iran. Several smaller iron ore deposits are distributed in the Alborz–Azarbaijan magmatic belt. There is a significant correspondence between the distribution of these deposits and main suture zones in the Iran plate composite. Stratiform iron deposits with a volcano-sedimentary origin are common features of the rifting phases of the future Prototethys and Neotethys oceans. Kiruna-type iron oxide deposits of the Zanjan area, and Fe skarn and iron oxide–copper–gold deposits in the Khaf–Bardaskan–Kashmar district are associated with subduction of Neotethys Ocean. Kiruna-type deposits within the Kashmar–Kerman magmatic arc are related to the Prototethys. Different geotectonic scenarios and their evolution explain the distribution patterns of most of the Fe and Fe–Mn deposits in Iran. Stratiform volcano-sedimentary Fe- and Fe–Mn deposits are related to the rift basin, and other types of Fe and Fe–Mn deposits such as the Kiruna-type deposits, skarn and iron oxide–copper–gold deposits in Iran are related to basin closure and plate collision. Magmatism in the subduction zone produced the magmatic and hydrothermal fluids, which caused Fe and Fe–Mn mineralisation in Central Iran microcontinent, Sanandaj–Sirjan magmatic–metamorphic zone, Alborz–Azarbaijan magmatic belt, east of Central Iran and the Lut blocks. The Central Iran microcontinent (Khaf–Bardaskan–Kashmar district), east of Central Iran, the Sanandaj–Sirjan zone and the Alborz–Azarbaijan belts are the most prospective districts for Fe and Fe–Mn exploration. Based on the age data on the studied deposits, favourable time periods for the largest Fe and Fe–Mn mineralising events in Iran were the Neoproterozoic–lower Cambrian (volcano-sedimentary and Kiruna-type deposits), upper Paleozoic–lower Mesozoic (volcano-sedimentary iron deposits) and Cenozoic (Kiruna type, iron oxide–copper–gold deposits and especially skarn deposits).