Facies Evolution and Lake-Type Variability Related to Climatic Cycles in the Late Triassic Çakrazboz Formation, Western Pontides, Türkiye
TURKIYE JEOLOJI BULTENI-GEOLOGICAL BULLETIN OF TURKEY, cilt.69, sa.1, 2026 (ESCI, TRDizin)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 69 Sayı: 1
- Basım Tarihi: 2026
- Doi Numarası: 10.25288/tjb.1765110
- Dergi Adı: TURKIYE JEOLOJI BULTENI-GEOLOGICAL BULLETIN OF TURKEY
- Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Central & Eastern European Academic Source (CEEAS), TR DİZİN (ULAKBİM)
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
The & Ccedil;akrazboz Formation, located in the Amasra-Kastamonu region of the Western Pontides (NW T & uuml;rkiye), represents the only known Triassic continental sedimentary succession in T & uuml;rkiye. This study integrates sedimentological, petrographic, and stratigraphic data from six measured sections to reconstruct depositional environments and evaluate paleoclimatic controls. Field and thin-section analyses reveal a complex facies mosaic comprising three major lithofacies groups: lacustrine, palustrine, and fluvial. Lacustrine facies are represented by carbonate-rich successions, including micrite, wackestone, and packstone, indicating low-energy profundal to sublittoral settings. Palustrine facies, occurring predominantly in marginal lake environments, are characterized by pedogenic overprinting, fenestral fabrics, root traces, and desiccation features, with the Bozk & ouml;y and Ba & scedil;k & ouml;y-1 sections showing more pronounced development of these features. Ba & scedil;k & ouml;y-2 and Ba & scedil;k & ouml;y-3 exhibit fluvial point-bar deposits with upward-fining successions and pedogenically modified mudstones, representing meandering river systems deposited during overfilled lake stages. Stratigraphic and sedimentological evidence indicates that the basin experienced repeated shifts between underfilled, balanced-fill, and overfilled lake stages. Carbonate-rich successions in the & Ccedil;akrazboz and lower & Idot;ncigez sections represent low-energy profundal lacustrine conditions typical of underfilled stages. The upper & Idot;ncigez and Ba & scedil;k & ouml;y-1 sections preserve features of balanced-fill conditions, with fining-upward transgressive intervals overlain by progradational littoral facies. Overfilled conditions are locally recorded in Bozk & ouml;y and in the upper parts of Ba & scedil;k & ouml;y-1, as evidenced by laterally extensive successions that thicken and coarsen upward, reflecting sustained freshwater inflow. These vertical facies transitions, stacking patterns, and diagenetic overprints are indicative of orbitally forced lake-level fluctuations under subhumid to semi-arid climate regimes, contributing to a broader understanding of Late Triassic continental basin evolution, facies architecture, and climate-controlled sedimentation.