Reconstruction of a Late Jurassic-Early Cretaceous carbonate platform margin with composite biostratigraphy and microfacies analysis (western Sakarya Zone, Turkey): Paleogeographic and tectonic implications

摘要: Abstract During Late Jurassic–Early Cretaceous the Pontides were site of a wide carbonate platform facing Tethys ocean in south. In western Upper Jurassic–Lower shallow marine carbonates abut Tethyan Izmir-Ankara suture with no evidence for margin deposits. The Sivrihisar klippe 50 km south preserves record missing margin. exposed this klippe, two coeval but dissimilar rock packages, separated by thrust fault, have been detected. lower succession is composed Kimmeridgian–Valanginian slope to basin Within these following biozones are defined: Globuligerina oxfordiana – Mohlerina basiliensis Zone (Kimmeridgian), Saccocoma (lower Tithonian), Protopeneroplis ultragranulata (upper Crassicollaria ( massutiana Subzone uppermost Calpionella alpina , Remaniella elliptica Subzones Berriasian), Calpionellopsis simplex oblonga upper Berriasian) and Calpionellites darderi Valanginian). These deposits overthrust from north Kimmeridgian carbonates. unit Labyrinthina mirabilis striata (Kimmeridgian) recognized. Based on distribution microfacies types fossil assemblages, depositional model proposed Sakarya Carbonate Platform (SCP). position studied sections respect SCP, biofacies associations suggest that represent remnants southern largely truncated erosion. basinal overthrusted region situated main indicates an important imbrication shortening related closure ocean.