Late Campanian (74–71 Ma) Arabia–Eastern Anatolia Collision and Its Geodynamic Implications

Abstract

The East Anatolian Plateau is a major collisional feature within the Tethyan realm formed as a late-stage result of the collision between East Anatolia and the Arabian Platform. The timing of this collision is highly debated, with estimates from the Late Cretaceous to the Miocene. This study presents new biostratigraphic and detrital zircon U–Pb–Hf data from upper Campanian and Danian siliciclastic rocks of the Arabian Foreland Basin, ∼40 km south of the Bitlis Suture. Upper Campanian rocks contain a dominant zircon age cluster (100–83 Ma) with εHf(t) values ranging from −7 to +6, whereas overlying Danian sandstones yield broader age spectra with clusters at 100–65 Ma, 750–500 Ma, and 1,100–800 Ma. The absence of Late Cretaceous magmatism on the Arabian Plate indicates derivation from the magmatic arc north of the Bitlis Suture. The late Campanian–Danian provenance shift likely reflects erosion of the upper arc and exhumation of metamorphic massifs representing middle- to lower-crustal levels of the magmatic arc and the subducted Arabian margin, indicating that the Arabia–Eastern Anatolia collision began in the late Campanian (∼74–71 Ma). Reassessment of published detrital zircon data from the Iranian foreland suggests later collision along the Zagros Suture (Maastrichtian-early Paleocene in the Kermanshah and Khorramabad areas). Final Eurasia–Arabia suturing occurred along the İzmir–Ankara–Erzincan and Zagros sutures, linked across West Azerbaijan (Iran), providing a coherent explanation for the pronounced Mesozoic–early Cenozoic geological contrasts between Eastern Anatolia and NW Iran.