ИСТИНА

In August 2016, within the framework of preparation for the VII International Conference on Cryopedology, a reconnaissance trip was made by the author together with A. Desyatkin and N. Fillipov along the Magadan Highway from Yakutsk to Khandyga and Oimyakon. Preliminary results for the described eight soil profiles are presented. In general, the mountainous part of the trip can be subdivided into three sections with different soil cover patterns and environmental conditions and with distinct orographic boundaries. The Sette-Daban Ridge with relative heights of more than 1000 m is characterized by the high portion of rock outcrops, including calcareous rocks, and thin skeletal soils. Thin petrozems (O–R(ca)) predominate on northern slopes under lichen larch forests; peat lithozems (T–С(ca)–R(ca)) are developed on southern slopes under herb–moss birch–larch forests. The Suntar-Khayta Ridge with relative heights of up to 800 m is more diverse in terms of the bedrock lithology, including dark slates. Raw-humus lithozems (AO–(С)–R) and humus petrozems (W–R) are common on northern slopes under lichen larch forests; raw-humus lithozems and peat lithozems are developed on southern slopes; local drainage conditions are important. The Oimyakon Highland with relative heights of up to 300 m has gently inclined surfaces with considerable accumulations of loose loamy materials with ice wedges; podburs and podzols are common of loamy gravelly substrates, and thin pelozems (O–C) are developed on silty clay substrates. Most of the soils are slightly acid; in profile T5 (podbur), the reaction is very strongly acid (pH 2.8–3.6); in profile T1 (calcareous substrate), the pH is 7.2.