Sedimentary Characteristics and Depositional Model of the upper Paleocene – Eocene Halkapinar Formation in the Southern Ulukişla Basin, Türkiye

The sedimentary dynamic of the Paleogene deep marine clastic system of the Halkapınar formation provides valuable information for understanding the complex geological history of the Ulukışla basin. This study aims to investigate the sedimentological characteristics of the Halkapınar formation and the paleoenvironmental framework in which the deposition occurred along with the related processes. Detailed sedimentological studies combining facies analysis with field observations indicated that the formation consists essentially of gravity flow deposits accumulated in a deep water setting spanning from the continental slope to the basin floor. The prime mechanisms accountable for sediment accumulation encompass slide, rock fall, debris flow, high-density turbidity current, low-density turbidity current, and suspension fallout. The sedimentary succession is composed predominantly of carbonate-rich turbiditic sandstone with mudstone intercalations, siltstone, and subordinate conglomerate containing clasts most likely derived from the adjacent Bolkar platform and to a lesser extent from the Alihoca Ophiolitic Mélange. The fragmentation of these source areas is mainly attributed to tectonic activity and erosion. Additionally, the occurrence of volcaniclastic sandstones in some localities documents the existence of a volcanic source that provided detritus to the basin. Facies distribution along with depositional architecture of the formation strongly suggest a sedimentation associated with the slope apron system.