SEDIMENTOLOGICAL AND PALYNOLOGICAL ANALYSIS OF THE CENOMANIAN-TURONIAN EVENT IN NORTHERN SIBERIA

Abstract

"Oceanic Anoxic Event" on the boundary of Cenomanian-Turonian (OAE2) is a bright episode in Cretaceous history. Results of the sedimentological and palynological researches of Cenomanian-Turonian of terrigenous deposits on the Lower Agapa River (Ust'-Yenisei region) are introduced. Sedimentological features of deposits and their facies relationships have been studied in detail. The rhythmicity of anoxic and normal-marine situations is revealed characteristic for "Black shale" facies. It is well expressed in shift of shallow marine sandy formations with benthonic faunas by black and dark gray fissile clays with pyrite, without macrofaunas, reflecting situations of stagnation. Qualitative and quantitative variations in structure of organic-wall microphytoplankton, dynamics of taxonomical diversity of dinoflagellate cysts are fixed depending on facies. The distribution of palynomorphs in Cenomanian-Turonian sediments in different locales is held.