Abstract: The two outcrops of Holocene peat with ice wedges in the mouth of Salemlekabtambda River in the Mammoth Peninsula are the object of the study, such as Holocene peat in the bog meadow of Kara Sea and the peat inset in the 15 m terrace. Ice wedges occur in the meadow bog sediments, their height is about 1.5 m. The height of ice wedges in the terrace sediments is about 4.5 m. We studied pollen spectra both, in the ice wedges and their host sediments, as well as determined isotope composition of ice wedges. Series of 14C ages have been obtained. The obtained isotopic and pollen data demonstrate that in the North of the Gydan Peninsula the Holocene optimum was the time of increase of climate continentality. Summer was warmer by 1-3°C than today, and winter was by 2-3°C colder. The intensity of frost cracking and ice wedge formation increased both in organic and mineral alluvial and alluvial-marine sediments.