Bio- and isotope stratigraphy of the Cenomanian-Turonian transition and the variations related to OAE2 in the Holul section, west of Kermanshah

Abstract

Micropalaeontological study based on planktonic foraminifera in the Cenomanian - Turonian succession of the Holul section, located in the Lurestan geological province (west of the Kermanshah City), resulted in distinction of Rotalipora cushmani, Whiteinella archaeocretacea and Helvetoglobotruncana helvetica biozones. Whiteinella archaeocretacea biozone globally defines the Cenomanian - Turonian transition. Detection of this biozone in the Holul section could be a clue for continuous sedimentation of the Cenomanian - Turonian transition in the studied stratigraphic section. Elongated chambers planktonic foraminifera such as Muricohedbergella simplex are relatively common during time span of Whiteinella archaeocretacea biozone in the Holul stratigraphic section. Results of the isotopical analysis in the studied section indicates an increasing - decreasing trend from the top of Rotalipora cushmani to the base of Helvetoglobotruncana helvetica biozones including two positive shifts before and after Whiteinella archaeocretacea biozone that can be correlated with carbon isotope peaks of OAE2 in the Neotethys Basin.

Keywords

• Biostratigraphy
• Planktonic foraminifera
• Carbon isotope
• Cenomanian/Turonian transition
• OAE