The main geological base consists of Upper Triassic, Lower Jurassic and Upper Cretaceous water-permeable limestones and in some places water-impermeable, clastic, Upper Eocene flysch deposits. The tectonic feature of the terrain shows a high degree of fracture and the basic feature are faulty wrinkles, which gives the area the characteristic of scaly structural structure. Such structural-tectonic features play a crucial role in the development and presence of hydrogeological phenomena. Waterproof clastic flysch deposits with the hydrogeological function of a complete barrier enabled the formation of one larger, permanent and several smaller periodic water sources.
