SPELEOGENESIS IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR ON THE KRASNOVIDOVO - TETYUSHA SITE
The Volga coast in the Republic of Tatarstan is well known for the presence of karst and numerous caves. In1957, after the creation of the Kuibyshev reservoir, an active change of its shores began. Many caves have been destroyed and flooded. At the same time, new conditions for speleogenesis have been created. As a result of abrasive and gravitational processes in the coastal zone, numerous wave-breaking niches, grottos, caves, and arches are formed in the carbonate-sulfate deposits of the Kazanian tier of Permian system. In total, more than 70 such forms were investigated from 2001 to 2021 in the site from Krasnovidovo village to Tetyushi town. The article briefly describes them and discusses their general and particular conditions of formation. We have observed some of them from the moment of their origin to the moment of their complete destruction.Special attention is paid to the development of secondary natural cavities above the mouth’s parts of galleries. Gypseous mine workings, which were flooded, were opened as a result of the retreat of the coast. When the entrance sections of the galleries are destroyed, gravitational domes are formed in the coastal zone, the drift of which does not stop. Cavities isolated from the mine are actively developing in the red-colored sediments of the Urzhumian tier of Permian system.