Micromorphological investigations into periglacial deposits of the Abalakh accumulative plain (Central Yakutia)
A.A. KUT1, V.V. SPECTOR1, B. WORONKO2, H. JIN3
1Melnikov Permafrost Institute, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russia
2University of Warsaw, Warsaw, Poland
3Northwest Institute of Eco-environment Resources, Chinese Academy of Sciences, Lanzhou, China
Keywords: sedimentation environment reconstruction, ice complex, quartz grain microtexture, Central Yakutia
Abstract
This paper considers periglacial sediments of the high accumulative Abalakh plain located in the interfluve of the Lena and Amga rivers (Central Yakutia). The genesis of loose deposits is determined, and the role of various sedimentation processes in their formation is revealed. Results were obtained on the basis of the cryolithological description of 94,5-meter borehole drilled in 2018. An analysis was made of the degree of roundedness and frosting of the surface of quartz grains. Diagnostic elements on the particle surface characteristic for different sedimentation processes are identified. An assessment of the relationship in the composition of quartz and feldspar grains was made. It was established that the layer under consideration has an alluvial (Tobolsk and Samara-Taz horizon) and lacustrine-alluvial genesis (Zyryanka horizon). It is pointed out that aeolian processes were also involved in sedimentation of the Tobolsk horizon. The source for deposits in the profile of the Abalakh plain was provided by loose deposits of short-range transport which were processed in the fluvial environment. Evidence for post-sedimentation processes of frost weathering was discover in deposits of the Zyryanka Samara-Taz horizons. It was established that loamy deposits of the ice complex were produced as a result of a complicated set of processes including frost weathering, aeolian transportation in a suspended state, and accumulation in stagnant basin conditions.
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