Abstract: The study focuses on palsa and high-centered polygonal peatlands. Engineering surveys for construction in bumpy permafrost peatlands are complicated by the lack of clear criteria for distinguishing between different types of mounds, such as palsa and high-centered polygonal peatlands. These mounds differ in height, shape, and distribution of their main engineering components. These two kinds of bumpy permafrost peatlands respond to human impact in rather different ways throughout structure operation, necessitating distinct safeguards. In this sense, techniques for more precise mound identification needs to be developed early on in engineering and environmental surveying. Examining the distribution of the carbon to nitrogen ratio in the peat that covers the mounds could be one strategy. The remaining landforms known as high-centered polygonal peat blocks were created "passively" by thermokarst processes along the frost-breaking cracks, with vein ice separating them. Palsa peat massifs are mostly found in the sporadic permafrost zone, though they are also frequently observed in the discontinuous and even continuous permafrost development zones, such as the Norilsk region, the Putorana plateau, the Mirny region of Yakutia, Chukotka and Kamchatka, etc. The thickness of peat on both convex and flat surfaces It is typically high, ranging from 1 to 3 meters, but rising to 5 meters and occasionally 8 to 9 meters on convex mounds. Palsa and high-centered polygonal peatlands exhibit distinctive genesis, height, shape, and distribution of engineering and geological characteristics, particularly ice content. Improved methods for identifying mounds during early stages of engineering and environmental studies are needed. One approach could be to analyze the carbon and nitrogen ratios in the peat covering the mounds. Palsa peatlands have higher carbon content (50-55% on average) and lower nitrogen content (0.5-2.0%) compared to high-centered polygonal peatlands (35-40% carbon and 1.5-2.5% nitrogen). The C/N value in peatlands varies, with palsa ranging from 30-36 (reaching -240) and high-centered polygonal peatlands rarely exceeding 25-27 (often 10-20).

Abstract: The object of this research is the organic-mineral deposits of the Late Pleistocene polygonal ice-wedge complex. They are studied in the outcrop of the second terrace, located on the left bank of the Mongatalyangyakha River, 3 km west of the estuary (71 ° 58'60 "N, 75 ° 16'0" E), on the Yavay Peninsula in the north of the Gydan Peninsula. The botanical composition of allochthonous peat in the upper part of the section is dominated by the remnants of Ledum palustre, and in the organic-mineral sediment the remains of Drepanoladus fluitans, Calliergonella cuspidata (or Calliergon cordifolium) are prevalent. A field outcrop study was performed; three wells were drilled. Palynological and hydrochemical diagrams were constructed and the radiocarbon age of the Late Pleistocene polygonal massif was determined. The main conclusions of the study are: 1. The age of the organic-mineral deposits varies from 30,200 to 21,900 years BP. 2. The rate of accumulation of organic-mineral deposits in the Karginsky time at the mouth of the Mongatalyangyakha River is about 0.25mm/year. 3. According to the palynological analysis, three local pollen zones are distinguished.