Triassic-Cretaceous sedimentary and magmatic development of the classic SW outcrop of the Antalya Complex, S Türkiye as a developing rift and passive margin bordering the Southern Neotethys

Abstract

The SW segment of the Antalya Complex (Antalya nappes) documents sedimentation, magmatism and tectonics related to Permian-Triassic continental rifting, Jurassic-Cretaceous passive margin subsidence, Late Cretaceous ophiolite genesis, and latest Cretaceous initial emplacement. Pulsed rifting took place during Late Permian and Early Triassic, followed by continental break-up during Late Triassic, and then Jurassic-Late Cretaceous (Santonian) passive margin subsidence. In the west, the Lower Antalya Unit records Late Triassic (Norian) rifting and collapse of the adjacent carbonate platform (Bey Dağları), then latest Triassic (Rhaetian)-Cenomanian development of a channelised carbonate slope with redeposited shallow-water carbonates. The Middle Antalya Unit begins with Mid-Triassic (Ladinian) radiolarites, overlain by Middle-Upper Triassic siliciclastic turbidites, deep-water hemipelagic carbonates (drift deposits) and radiolarites. Alkaline volcanics erupted during Late Triassic in a deep-water setting. Deep-water radiolarites characterised Rhaetian to Late Cenomanian-Turonian. Within the Upper Antalya Unit farther east, above pre-rift and early syn-rift crust, Middle Triassic (Ladinian) radiolarites were followed by Upper Triassic hemipelagic carbonates, then uppermost Triassic-Cenomanian shallow-water platform carbonates. The SW Antalya Complex restores to the northern margin of the Southern Neotethys. The upper unit (Cambrian-Devonian) rifted during Late Permian, Middle Triassic (Ladinian) and Late Triassic (Carnian-Norian). Rift-related flexural and/or thermal uplift preceded seafloor spreading, similar to the Central-Northern Red Sea. Dismembered ophiolitic rocks were emplaced from the adjacent Southern Neotethys during the latest Cretaceous. Initial ophiolite emplacement resulted in collapse of the passive margin and transgression by mass-flow deposits. Initial emplacement by thrusting and strike-slip, during late Campanian-Maastrichtian, was followed by Paleocene, Eocene and Miocene emplacement events.