Sedimentary characteristics of early Miocene platform deposits in the Neogene Adana Basin, southern Turkey


Abstract: We report a detailed description of the sedimentological characteristics of the Early Miocene platform deposits to contribute towards the understanding of the evolution of the Neogene Adana Basin (southern Anatolia). Several detailed sedimentological logs were measured and interpreted from the platform deposits (Kaplankaya, Karaisalı, and turbiditic Cingöz formations) of the Adana Basin. The depositional evolution of the Adana Basin began during the Early Miocene as a foreland basin. The basin fill is both marine and nonmarine in character, which shows a gradual transition at the northern margin of the basin from one into another. Formation of the basin commenced by a major marine transgression during the Early Miocene. The pre-Miocene sedimentation area was a large platform with an adjacent depression area, which greatly affected the development of Miocene sedimentation after the Aquitanian-Burdigalian transgression. Prior to this transgression, the paleotopography was filled by terrestrial Gildirli deposits, and after transgression, shallow platform sediments of Kaplankaya-Karaisalı formations, and Cingöz and Güvenç formations were deposited in the slightly deeper parts of the basin. The Early Miocene Kaplankaya and Karaisalı formations conformably overlie the Gildirli Formation. However, both formations are seen resting with angular unconformity on the tilted Oligocene age Karsantı Basin sediments. Early Miocene sediments were developed due to the transgression towards the north. In the areas close to the shore, the northerly sourced littoral-brackish and deltaic Kaplankaya Formation and the more marine reefal Karaisalı Formation were deposited. Stratigraphical, sedimentological, and paleontological evidence has proven that the platform sediments of the basin were deposited during the Aquitanian-Burdigalian. While the Karaisalı Formation is represented by reef sediments, the base of Kaplankaya is characterized by alluvial fan and distributary mouth bar deposits with intermittent fluvial and marine conditions. These pass upward into prodelta clayey facies that consist of shallow marine fossils. The Burdigalian-Serravalian turbiditic Cingöz Formation cuts the Kaplankaya Formation with a channelized erosive contact.

Keywords: Adana Basin, Foreland Basin, Neogene sediments, sedimentary environment, southern Turkey

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