ABSTRACT: Larger foraminifera of the late Cretaceous (late Campanian) to middle Eocene (Lutetian) are recognized in the upper Cretaceous to Paleogene sedimentary rocks in the Haymana and Black Sea regions, Turkey. 114 diagnostic larger and benthonic foraminiferal species belonging to 66 genera including one new genus Chaldagia are identified, and 89 diagnostic species are documented as local ranges. Biostratigraphically useful 11 larger foraminiferal assemblage zones are described, and are correlated with two larger foraminiferal assemblage zones, NE India and Philippines in the Tethys region. Chaldagia haymanensis, n. gen., n. sp. and Scandonea samnitica De Castro are systematically described. Associated 52 planktonic foraminiferal species belonging to 23 genera are identified, and 90 larger and benthonic foraminifera and 40 planktonic foraminifera are illustrated. Some element concentrations of the Cretaceous-Tertiary (K-T) boundary layers (28-37 cm thick with goethite layers) were found in the MedetlÃ section, GÃ¶rpazari, Black Sea region by the authorâ€™s research group. In there, Ir concentration was low and slightly elevated (0.24 ppb) in a sample of goethite layers, and foraminiferal taxa didnâ€™t yield. The K-T Ir layers are well correlated with those in the Meghalaya, NE India. Sr isotope values (87 Sr/86 Sr, 0.707885 â€“ 0.707819) in the K-T boundary layers in the Devrekani section, Kastamonu, Black Sea region agreed well with those in the K-T boundary regions of the world by the authorâ€™s research group.