The paper presents new data on the structure, lithology, paleopedology, geomorphology, and radiocarbon geochronology of Late Pleistocene and Holocene deposits in the Nadym Ob area of the West Siberian Plain. The study reveals several distinct events in the Late Pleistocene and Holocene climate and deposition history of the area. Fluvial deposition during the first stage corresponding to the end of MIS-3 (Karga interstadial) produced the second river terrace. During the next stage, in the Last (Sartan) Glacial (MIS-2), primary sand wedges formed as frost cracks became filled with aeolian sand. The presence of sand wedges is inconsistent with the existence of ice sheets in the area during MIS-2. The first terrace of the Nadym River and its tributaries accumulated during the third stage (from about 10.7-10.3 Kyr BP), and peatbogs were formed in the Holocene. The latest stage began in the late Holocene after a long deposition gap and produced aeolian sands accumulation upon the second and first river terraces. The aeolian sand deposition for the past 1200 years was punctuated by short episodes of soil formation and vegetation growth in a slightly warmer and moister climate.
|Состояние||Опубликовано - 1 янв 2017|