Earth`s Cryosphere, 2019, Vol. XXIII, № 2, p. 25-32
GROUND ICE CONTENT OF FROST MOUNDS IN THE NADYM RIVER BASIN
N.M. Berdnikov1, A.G. Gravis1, D.S. Drozdov1–4, O.E. Ponomareva1,2,
N.G. Moskalenko1, Yu.N. Bochkarev1,5
1 Earth Cryosphere Institute, Tyumen Scientific Centre SB RAS,
P/O box 1230, Tyumen, 625000, Russia; nikolaj-berdnikov@yandex.ru
2Russian State Geological Prospecting University (MGRI–RSGPU), 23, Miklukho-Maclay str., Moscow, 117997, Russia
3 Tyumen State Oil and Gas University, 56, Volodarskogo str., Tyumen, 625000, Russia
4 Тyumen State University, 6, Volodarskogo str., Tyumen, 625003, Russia
5 Lomonosov Moscow State University, Faculty of Geography, 1, Leninskie Gory, Moscow, 119991, Russia
The “classical type” ice-cored frost mounds (palsas) are widespread in the northern taiga of Western Siberia. Besides, morphologically different forms of permafrost hummocky landforms are developed, differentiating from the “classical” frost mounds by size and flatter top surface. Using core samples from ten-meter deep boreholes, we have analyzed the total thickness of segregated ice and the contribution of ice inclusions to the total soil ice content, to determine the origin of such flat-topped mounds. A good correlation has been revealed between surface elevations and volumetric ice content of sediments composing flat-topped peat mounds, whose ice content is found to be higher than in the intermound depressions. These facts indicate the local nature of ice segregation and therefore suggest that the investigated landforms were formed by the frost heave processes, rather than being remnant permafrost landforms.
Frost mound, remnant permafrost landforms, ice content, segregation ice, volumetric ice content