Journal of Asian Earth Sciences, cilt.308, 2026 (SCI-Expanded, Scopus)
Eastern Anatolia preserves one of the most extensive sedimentary records documenting the final stages of marine deposition associated with the progressive closure of the Neotethys Ocean during the Oligocene–Miocene transition. Despite its paleogeographic importance, the chronostratigraphic framework of many marine successions in this region remains poorly constrained, limiting regional correlations and interpretations of basin evolution during the Arabia–Eurasia collision. This study presents an integrated chronostratigraphic investigation of five well-exposed marine sections in Eastern Anatolia (Yedisu, Aşkale, Çobanbeyi, Çayırlı, and Hamamlı). Field-based stratigraphic observations are combined with calcareous nannofossil and planktonic foraminiferal biostratigraphy and strontium-isotope stratigraphy to establish a robust temporal framework for the Late Oligocene–Early Miocene marine successions preserved in these basins.The integrated dataset indicates that marine sedimentation in Eastern Anatolia persisted from the late Oligocene into the Early Miocene and continued locally until approximately 16.3 Myr (Burdigalian). Lithofacies characteristics and fossil assemblages reveal deposition predominantly in shallow-marine environments, with local variations between relatively open shelf conditions and more restricted marginal basins. These results demonstrate that several Eastern Anatolian basins maintained marine conditions well into the Early Miocene, before tectonically driven uplift and basin reorganization associated with the Arabia–Eurasia collision initiated the transition to continental sedimentation.The persistence of marine environments until the Burdigalian suggests that Eastern Anatolia represented one of the last marine domains along the eastern segment of the former Neotethyan seaway prior to its final regional withdrawal. The new chronostratigraphic framework presented here refines the timing of marine retreat in Eastern Anatolia.