High Quality Content by WIKIPEDIA articles! The Epoch of Extremal Inundations is the unique nature event in the past. This theory is about wide inundations in the Ponto-Caspian basins which have been associated not only with well-known marine transgressions but also with four landscapes: marine lowlands (marine transgressions), river valleys (superfloods), transgressions (thermocarst lakes) and slopes (solifluction flows). Events of Epoch of Extremal Inundations had catastrophic character and influenced on the ancient human life.