Refined age of the anoxic level in the Cenomanian-Turonian transition of the Mt. Sel'-Bukhra section (Crimean Mountains, Ukraine): Implications of radiolarian analysis.

A representative radiolarian assemblage has been macerated for the first time from beds enriched in organic matter at the time of the Oceanic Anoxic Event (OAE-2). The assemblage includes radiolarians characteristic of the late Cenomanian, and is barren of species typical of the incipient Turonian. Consequently, deposition of beds rich in organic matter terminated in the late Cenomanian. [ABSTRACT FROM AUTHOR]