On the question of stratigraphic detail Konkian deposits Borysthenian Bay (southern Ukraine) on the fauna of molluscs

The results of study marine bivalve and gastropod from konkian-sarmatian deposits of the Southern Ukraine are gave. Their lateral and vertical distribution is studied. Local stratigraphic schemes for the Northern Black Sea region, Plane Crimea and Kerch peninsula are built. It is confirmed the Konkian regional stage divisible into three parts: the Kartvel (Ervilia and Pholada), Sartagan and Veselyanka layers. The lower part (Kartvel layers) is characterized by monomorphic fauna of Ervilia and / or Pholada; other shellfish are virtually absent. The middle part (Sartagan layers) contains polihalin shellfish such as Turritella, Chlamys et al., but their findings are rare. In this common transit fauna, which can cause significant difficulties in the stratification of the regional stage. The upper part (Veselyanka layers) by the absence of (or single) polihalin elements and extensive development of some types of Cardiidae. The individual seams with Ervilia and Barnea met throughout the section tram and fauna differ from the Kartvel layers joint finding other taxa Konkian shellfish and usually less power. The possibility of fractional stratification Sarmatian regional stage in different structural-facial areas of the Southern Ukraine. Change shellfish communities on the border of the lower and middle Sarmatian occurs gradually in clay sediments and more clearly in the coastal sandy and sandy-clay rocks. Separation of Vasilyevsky and Dnepropetrovsk layers of middle Sarmatian malacofauna problematic in areas of strong recrystallized limestone. For the detail section is necessary to study rocks in thin sections