The geological structure is made up of: To the south, Coneyas – mastite (terrigenous-carbonate rocks), santon – mastrite (terrigeno-carbonate rocks), zenoman Middle Turon, Upper-Aryah Formation (marls and clay marls with interbeds of sandstones, sandstones), sand marbles, Krivnen Formation in places sandstone, Seshev Formation – siltstones and often glauconites.