Lower Palaeozoic-Paleogene geological development of a deep-water rift (Güzelsu Corridor) along the northern continental margin of the Southern Neotethys in the Eastern Mediterranean region: Evidence from the Antalya Complex and the adjacent Tauride Carbonate Platform

Abstract

Rift basins in mountain belts shed light on the palaeogeography and tectonic development of adjacent sutured ocean basins, as for the Antalya Complex in the S Neotethys region. Based on literature review, supplemented by multidisciplinary new data, the Antalya Complex in this area represents an Upper Permian-Triassic rift basin and subsequent Jurassic-Cretaceous passive margin that encompasses a marginal shallow-water carbonate platform, slope facies and deeper water axial pelagic sediments and basaltic volcanics. The rift basin was bordered to the north by the Tauride Carbonate Platform, and to the south by the metamorphic Alanya Massif farther south. The S Neotethys was located further south, adjacent to N Africa.The evidence comes from a critical but little known E-W trending segment of the Antalya Complex (Antalya Nappes) in the east of the regional Isparta Angle (an orocline), known as the Güzelsu Corridor. To the south of the Tauride Carbonate Platform, the Güzelsu Corridor exposes three tectonic units within the Antalya Complex of Early Palaeozoic-Late Cretaceous age. The Lower Unit represents the proximal-distal slope of the Tauride platform. The Middle Unit preserves U. Permian-U. Cretaceous axial rift and passive margin settings. The Upper Unit (Gündoğmuş, Kavzandağ and Katrandağ thrust sheets) documents L. Palaeozoic pre-rift sediments, unconformably overlain by Permian-Triassic syn-rift units and a post-rift Jurassic-Cretaceous carbonate platform.Geochemical data highlight the rift-related setting of Upper Permian and Upper Triassic basaltic rocks in both the Middle and Upper Units. Radiolarian biochronology shows that the Middle Unit includes radiolarites of Late Triassic to Late Cretaceous (Campanian) age. Calcareous microfossil data shed light on facies development within the Antalya Complex and along the southern margin of the Tauride Carbonate Platform. Sedimentological and petrographic evidence help indicate depositional environments and processes. Structural data shed light on the emplacement of the Antalya Complex and its relation to the metamorphic Alanya Massif. Comparisons with counterparts of the Antalya Complex around the periphery of the Isparta Angle provide a regional palaeogeographic context.The Antalya Complex in the study area began to rift during the Late Permian, with initial localised alkaline basaltic volcanism. Further rifting (pulsed) and deepening took place during the Early to Middle Triassic. More extensive alkaline volcanics erupted during the Late Triassic (Carnian), coupled with terrigenous turbidites (Mid-Late Triassic), culminating in continental break-up to form the S Neotethys regionally (Carnian-Norian). Accumulation below the carbonate compensation depth took place within the deep-water rift basin during Jurassic-Late Cretaceous.Related to Late Cretaceous subduction, the Alanya microcontinent subducted northwards beneath the Antalya rift and the Tauride Carbonate Platform to the north. Initial collision dissected the rift and its margins into the three major tectonic units. Polymictic debris flows (olistostromes) were emplaced onto the southern margin of the Tauride platform during the latest Cretaceous (Campanian-Maastrichtian). Following partial exhumation, the Alanya Massif was thrust northwards, shedding metamorphic debris onto the adjacent Tauride platform (Early-Middle Eocene). Post-suture tightening (e.g., transcurrent faulting) occurred prior to Miocene transgression. The regional Eocene deformation was probably driven by final closure of Neotethyan ocean farther north.