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The Arabia – Eurasia collision zone in the central part of the Alpine – Himalayan orogenic system has had a complex deformation history since the Palaeozoic. In Iran, the collision zone consists of the Alborz‐Talesh, Kopeh Dagh and Zagros foldbelts and the intervening Central Iran area. In this review paper, we summarize the structural architecture and tectonostratigraphic characteristics of these domains and attempt to correlate regional deformation events between them. The results show that six regional‐scale deformation phases can be recognized and correlated in Iran over a time interval extending from the Late Palaeozoic to the Late Cenozoic. Late Palaeozoic rifting in northern Gondwana and subsequent oceanic spreading resulted in the separation of the Central and North Iran blocks from the Arabian Platform. These blocks later converged and collided with the southern margin of Eurasia due to the subduction of the intervening PalaeoTethys lithosphere ("Cimmerian orogeny": Late Triassic). The convergent setting resulted in the initial development of the Alborz‐Talesh foldbelt in present‐day northern Iran, while extensional basins developed in the forebulge area in Central Iran. Continuing northward subduction of NeoTethyan oceanic lithosphere at the southern Eurasia margin produced Early Cretaceous back‐arc extension and associated volcanism in Central Iran and the Alborz‐Talesh area to the north. A phase of compressional deformation in the Late Cretaceous was related to the collision of a series of microcontinents derived from Northern Gondwana, including the Ercinjan and Bitlis massifs, with the Central Iran block, and is recorded in the Alborz‐Talesh foldbelt and in Central Iran. Further back‐arc extension in the late Paleocene – Eocene was accompanied by pervasive volcanism and volcaniclastic sedimentation throughout northern and Central Iran. The final closure of NeoTethys and convergence between the Arabian and Eurasian Plates evolved through phases of early Oligocene "soft" collision and middle Miocene "hard" collision. This was accompanied by thrusting in the internal parts of the Zagros foldbelt and by folding and subordinate thrusting in the more external parts, with related development of the flexural Mesopotamian Basin in the foreland to the SW. [ABSTRACT FROM AUTHOR]

Regional convergence in Eurasia has been evolving since the collapse of the Soviet Union. The Commonwealth of Independent States was Russia's initial attempt to forge a comprehensive regional integration. However, Russia gradually shifted its focus to economics, and this produced the Eurasian Economic Union (EEU). This organization has concluded numerous cooperation agreements, even with countries outside the borders of Eurasia, raising questions about regional convergence. In addition, with the expansion of China's influence in Central Asia, there has been a shift in the role and scope of the EEU. Iran has concluded a preferential trade agreement with the EEU, including non‐tariff measures and a list of commodities for which barriers have been reduced or cut to zero. The main question of this study is how Iran's presence in this organization will influence Eurasian convergence. We examine the opportunities for, and obstacles to, convergence through an analysis of the forces that can bind an institution like the EEU: cultural and ideological affinities; the hegemony of the most powerful actors; and the potential for solving common problems. [ABSTRACT FROM AUTHOR]

The interpretation of low-temperature thermochronology (LTT) data in magmatic and metallogenic provinces requires a knowledge of the geothermal field through time. There, the challenge is differentiating rapid cooling following transient perturbations of the geotherms (reheating) from exhumational cooling induced by erosion during tectonic uplift or normal faulting. The Takab Range Complex (NW Iran) is a basement-cored range of the Arabia-Eurasia collision zone that experienced voluminous Eocene to Miocene magmatism and mineralization. Our new apatite and zircon (U-Th-Sm)/He and apatite fission track data, together with field observations, a dedicated numerical thermal model, and a re-evaluation of available geochronology data document the occurrence of a complex geological and thermal history including: (a) late Cretaceous-Paleocene exhumation possibly controlled by regional contractional deformation followed by Eocene deposition; (b) Oligocene to possibly early Miocene (29 to 22-20 Ma) exhumation of basement rocks from 13 to 8 km of depth, most likely through normal faulting during a thermal anomaly that led to migmatization and partial melting; (c) early to late Miocene (~22-20 or earlier to 11-10 Ma) regional subsidence with deposition of an up to ~2- to 3-km-thick Oligo-Miocene sedimentary sequence in association with the emplacement of shallow intrusions, which led to a partial to total reset of our LTT systems sometime between 18 and 13 Ma; and (e) erosional exhumation after 11-10 Ma with the development of a transpressional system and a master, right-lateral, strike slip fault (Chahartagh Fault). Our data highlights the impact of magmatic reheating on LTT ages in areas affected by intense magmatism. [ABSTRACT FROM AUTHOR]