Stratigraphy and Palaeoenvironment of the Lower-"middle" Oligocene Units in the Northern Part of the Western Taurides (Incesu Area, Isparta, Turkey)

Abstract

This study describes the stratigraphic and palaeoenvironmental significance of the Lower-"middle" Oligocene sediments based on the fauna from the Delikarkasi Formation and the microflora from the Incesu Formation of the Incesu area (northern part of the western Taurides, Isparta province, Turkey). In the area, the Oligocene sediments show a regressive succession, which begins with the limestones of the Delikarkasi Formation indicating marine conditions followed by conglomerates, sandstones and coaly mud-stones of alluvial and fluvial (shallow marine-continental) origin. A well preserved foraminiferal assemblage including Nummulites intermedius, Nummulites vascus and Halkyardia maxima proves an Early Oligocene age for the Delikarkasi Formation. Due to palynological markers such as Boehlensipollis hohli, Slowakipollis hippophaeoides, Dicolpopollis kockelii, Magnolipollis neogenicus ssp. minor, Plicapollis pseudoexcelsus, Caryapollenites simplex and Intratriporopollenites instructus the Incesu Formation, which concordantly rests on the Delikarkasi Formation, may be assigned to the Early-"middle" Oligocene. From the palynomorph assemblage, three zones have been recognised according to abundance of species. Zone 1 is characterized by predominance of C. simplex and Momipites punctatus and rarely presence of tricolpate and tricolporate pollen. Zone 2 consists mainly of Inaperturopollenites dubius, Leiotriletes maxoides ssp. maximus, Verrucatosporites favus, Verrucatosporites alien us and infrequently marine dinoflagellate cysts. Zone 3 is characterized by a high percentage of ferns such as Echinatisporis? chattensis and Polypodiaceoisporites saxonicus. The presence of marine dinoflagellate cysts like Apectodinium sp. and Cleistosphaeridium sp., back-mangrove elements such as Acrostichum aureum and lepidocaryoid palms (e.g. Longapertites discord is, Longapertites punctatus and Longapertites psilatus) in the sediments of the Incesu Formation imply coastal or near-coastal conditions. Terrestrial palynomorphs in more inland settings were transported by running water towards the sea. Conifers are represented by poorly preserved and rare pollen grains of Pityosporites, Cathayapollis and Piceapollis which may have been transported by wind. In this study, the terrestrial climate of the Incesu Formation is also discussed on the basis of the Coexistence Approach method. The climate was warm at the coast (over 20 degrees C), as evidenced by A. aureum and lepidocaryoid palms, whereas there was a mean annual temperature of 17.2-17.4 degrees C must be assumed for the upland environment(s). (C) 2010 Elsevier Ltd. All rights reserved.