Summary We use the tectonics of Eastern Anatolia to exemplify many of the different aspects of collision tectonics, namely the formation of plateaux, thrust belts, foreland flexures, widespread foreland/hinterland deformation zones and orogenic collapse/distension zones. Eastern Anatolia is a 2 km high plateau bounded to the S by the southward-verging Bitlis Thrust Zone and to the N by the Pontide/Minor Caucasus Zone. It has developed as the surface expression of a zone of progressively thickening crust beginning about 12 Ma in the medial Miocene and has resulted from the squeezing and shortening of Eastern Anatolia between the Arabian and European Plates following the Serravallian demise of the last oceanic or quasioceanic tract between Arabia and Eurasia. Thickening of the crust to about 52 km has been accompanied by major strike-slip faulting on the right-lateral N Anatolian Transform Fault (NATF) and the left-lateral E Anatolian Transform Fault (EATF) which approximately bound an Anatolian Wedge that is being driven westwards to override the oceanic lithosphere of the Mediterranean along subduction zones from Cephalonia to Crete, and Rhodes to Cyprus. This neotectonic regime began about 12 Ma in Late Serravallian times with uplift from wide-spread littoral/neritic marine conditions to open seasonal wooded savanna with colluvial, fluvial and limnic environments, and the deposition of the thick Tortonian Kythrean Flysch in the Eastern Mediterranean. Earthquake hypocentres are scattered throughout the region but large earthquakes are concentrated mainly on the major faults and are mostly shallow, supporting the idea of a brittle elastic lid with hypocentres concentrated towards its base with more ductile deformation in the middle and lower crust. Neotectonic magmatic suites are nepheline-hypersthene normative alkali basalts of mantle origin, and silicic/intermediate/mafic calcalkaline suites, both suites occurring in pull-apart basins in strike-slip regimes and along N-S extensional fissures, and both suites showing a strong change to central activity in the Pliocene. Upper-crustal strains appear to be discontinuous in space and time, with zones of strong shortening representing shoaling of crustal detachment zones flattening between 5 and 10 km. Approximately NW- (dextral) and NE- (sinistral) trending lineaments bound less deformed wedges (low relief seismically ‘dead’ areas) and vary from simple strike-slip faults to complicated braided transform-flake boundaries with pull-apart and compressional segments (N and E Anatolian Transform Faults). Volcanoes lie in grabens on N-S ‘cracks’ that extend into the Arabian Foreland and in transcurrent pull-aparts. Major extensional basins lie at plate (Adana) and flake (Karliova) triple junctions and result from compatibility problems.

Analysis of the geologic and geophysical data from the western and northern margin of the Arabian plate combined with data from the Red Sea/Gulf of Aden leads to an interpretation of Arabian plate motion that supports an episodic extensional history in the Red Sea and Gulf of Aden. Phase 1 extension began in medial to late Eocene and was caused by the NW propagation of the reoriented Central Indian Ridge spreading center. It stretched and thinned continental crust along numerous wrench and normal faults that reactivated preexisting structures. First‐phase extension stopped when the Arabian plate terminally sutured to Eurasia in the medial Miocene and halted northward movement of Arabia relative to Africa. The combined African/Arabian plates moved north more slowly, constricting and thickening continental crust in the Bitlis/Zagros sutures while the Red Sea remained technically quiescent and accumulated salt. By the early Pliocene, continued northward movement was accommodated by lateral extrusion of large continental wedges north of the Bitlis/Zagros sutures. This allowed Arabia to move northward faster than Africa and reopen the Red Sea where phase 2 extension was expressed by seafloor spreading. Extension within the Red Sea/Gulf of Aden rift system has been controlled by the interactions and effects of two factors: (1) convergent processes between the north margin of the Arabian plate and the Eurasian plate to the north and (2) northwest propagation of extension associated with the medial Eocene reorganization of the Central Indian spreading center.

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