The investogations were carried out in the middle flow of B.Chukuchya river on the North -East of Asia on 100x200 cm microarea. The pit has opened sevral regulary-cyclical soil microcomplexes. Right part of the front wall cuts through the nongrown spot-medallion through all its 50 sm length and 25 sm of wigth. This spot-medallion is joint the overgrowing spot 15-20 sm wide and 35 sm long, a part of which opened by the pit. The overgrown spot was opened on the second part of hillock on the back wall of the pit. Thus on the small area ( 100x120 sm ) the different tundra soils were revealed which were situated on the different elements of microrelief. They include:

1. tundra soddy humic soils of hillocks;
2. tundra gleyed soils of medallions;
3. tundra peaty humic gley soils of falls; and
4. tundra peaty soils of cracks.

Two spots are on the front wall: the more old spot is already covered by soum of grey lichens, sedge and red bilberry (essentially on periphery of spot) Close to the overgrowing spot sharply differ from it by the absence of vegetations a nongrown spot-medallion is situated. It is covered with thick net of microcracks 1 sm depth. They both form something like small polygones of irregular form. The surface of these polygones is covered by crust 0,2-0,3 sm thickness. The middle of polygones is a little swelled forming hillocks where lichens of grey, yellow and brown colour in form of points are already settled.

On morphological sign the soil under overgrowing and nongrown spots have no differences.

Alexandr. N. Butsenko
Institute of Soil Sciences and Photosynthesis, RAS
73-18-87, Lab. of Soil Cryology.
142292, Pushchino, Moscow Region, RUSSIA
Phone: (095) 923-35-58
E-mail gilichin@issp.serpukhov.su