Geochemical composition of Holocene syngenetic ice wedges of southern and central parts of the Yamal Peninsula (within the thick peat bogs in the Shchuchya River valley, the Seyakha settlement, the floodplain of the Lakkatoso River, and the vicinity of the Cape Kamenny settlement) was determined. The authors have analyzed the content of trace elements and heavy metals.Holocene ice wedges are ultra-fresh and fresh, their mineralization varies from 20 to 200 mg/l, hydrocarbonates and calcium dominate in the ion composition. Participation of chlorides in the ice wedges on terraces indicates the influence of marine aerosols, the same for the ice wedges on the floodplain means the direct participation water of Ob Bay in their formation. The increasing of iron ions in some fragments of ice wedges, comparable to their content in segregated ice in the peat bog, may indicate a periodic participation of swamp waters in the formation of ice wedges.

The mineralization and chemical composition of water-soluble salts in segregated ice and ice wedges were determined at the V.V. Dokuchaev Soil Science Institute.