Delta of the River Lena—a Great Extractive System in the Arctic Coast of Siberia

Geomorphological surfaces of different age and genesis are located on the territory of the Lena delta. The oldest are the remnants of the alluvial-marine plain (edoma, or third terraces) at heights of 50–60 m, composed of an ice complex of sediments and formed in the time interval from 100 to 50 thousand years ago (Ebo-Esme, Kurungnaah-Sise islands, Sordooh-Aryy, Kubalakh-Khaya, Sobo-Sise, Sardakh and the Bykovsky peninsula). The island of Arga-Muora-Sise is represented by a sea sandy terrace (the second) formed in the period from 50 to 15 thousand years ago at heights from 15 to 25 m. Most of the territory of the Lena Delta is occupied by sediments of high and low delta floodplain at heights from 1–2 to 5–10 m (the first terrace), composed of sandy-clay-peat alluvial-sea sediments accumulated over the past 7 thousand years in the form of regional mouth outflow cones on an area of about 25 thousand km2.