East-Siberian and North Chuckchi seas shelfs was the area of intensive deltaic sedimentation during Aptian-Late Cretaceous and Cenozoic times. Large deltaic systems prograded at distance of hundreds kilometers building up continental terraces. Thick sedimentary infill related to two clastic pulses: Aptian-Late Cretaceous and Cenozoic. A number of a paleogeographic maps reflect the major sedimentary epochs.