Akademik Veri Yönetim Sistemi
MICROPALEONTOLOGY, cilt.56, sa.5, ss.413-438, 2010 (SCI-Expanded)
The Lapta Group, Late Cretaceous-Middle Eocene in age, mainly consists of basal breccias, micritic limestones and clayey limestones with volcanic, calciturbidite and breccia interbeds. It unconformably overlies the Triassic-Lower Cretaceous platform carbonates in the Besparmak (Kyrenia) Range. The detailed study of planktonic foraminiferal assemblages obtained from three stratigraphic sections through the Lapta Group revealed six biozones: Racemiguembelina fructicosa Zone and Abathomphalus mayaroensis Zone of Maastrichtian age; and Acarinina uncinata Zone (P2), Morozovella angulata Zone (P3), Globanomalina pseudomenardii Zone (P4) and Morozovella velascoensis Zone (P5) of Paleocene age. The Cretaceous-Tertiary boundary and the lower part of the Danian including Guembelitria cretacea (P0), Pamtlarugoglobigerina eugubina (Pa) and Parvularugoglobigerina eugubina-Praemurcia uncinata (P1) zones have not been recorded. Absence of this interval has been attributed to the volcanic level between micritic limestones and clayey limestones in the lower part of the sequence. The clayey limestones of the Lapta Group are overlain by radiolarian calcareous mudstones which pass into alternating siltstone and sandstone of the Ardahan Formation. In contrast to the Lapta Group, the Ardahan Formation lacks zonal marker species and is characterized generally by poorly preserved, less diverse and less abundant planktonic foraminiferal assemblages which hamper biozonation. However, the occurrences of typical Middle Eocene planktonic foraminiferal taxa such as Acarinina bullbrooki (Bolli), Globigerinatheka kugleri (Bolli, Loeblich and Tappan), Globigerinatheka subconglobata (Shutskaya), Morozovella spinulosa (Cushman), Morozovella lehneri (Cushman and Jarvis), Truncorotaloides topilensis (Cushman) and Truncorotaloides rohri Bronnimann and Bermudez together with Turborotalia cerroazulensis cerroazulensis (Cole) and Globorotaloides suteri Bolli suggest a Bartonian age for the Ardahan Formation.