Massive deposits in reef were discovered in separate fields of Varandey-Adzva zone (Naulskoye, Labaganskoye, etc.). These bodies are represented by organogenic-detrital limestones, fractured with porosity of 8-10 %. They have the form of separate buildings, developed locally, wedging out along the strike within the same area. The deposits are confined to the secondary reservoirs of the pore and pore-fracture type.