Reflection of Wenlock oceanic episodes and events of the chitinozoan succession of Estonia

During this study the model of oceanic and climatic cyclicity by Jeppsson (J. Geol. Soc., 1990, 147) was applied in the Wenlock sequence of Saaremaa on the basis of chitinozoan succession. The boundaries of some Wenlock episodes and events, established in the reference sections of lreviken 3 and Vattenfallet outcrops, and Slitebrottet quarries of Gotland, were traced by chitinozoans in the Ohesaare section. In the paper the main changes in the chitinozoan assemblage during primo and secundo episodes and events are discussed. Diversity variations in primo and secundo episodes are expressed also in the monotonous marlstones of the Ohesaare core. The severest extinctions of the chitinozoan assemblage occurred during the Ireviken and Mulde events. The Boge and Valleviken events probably corresponded to an extensive stratigraphic gap in the sections of northern Saaremaa.