The concept of geomorphologic mechanism is put forward and analyzed. The method implies the creation of cinematic and dynamic schemes, the analysis of energy sources and main factors of landforms' development. Several geomorphologic mechanisms in the Pamir-Tien Shan contact zone are considered.

Intermountain plains, plateaus and hills located within the young continental orogenic belts are described. Different types of intermountain areas are distinguished according to their size and morphology. Some features of N-Q dynamics of these areas are under consideration.

The main fluvial development stages of the Russian Plain have been revealed. The result is based on the investigations of landforms and deposits of low terraces, flood-plains and river channels of Seim and Svapa rivers.

These stages are: I) 17-19 Ma B.P. - formation of constructive alluvium layers of sand and siltstone more than 10 m thick; 2) 14-17 Ma - formation of the large meandering river channels with discharge 6-7 times more and normal alluvium thick 1.5-2 times more than recent, 3) 10-14 Ma - the reduction of large channels and formation of inherited flood-plains and its deposits, 4) less than 10 Ma - formation of recent meandering river channels and the belt of segment-ridges flood-plain under the conditions of long-period changes of water discharge.

The using of entropy-informational evaluation of the morphometric characteristics showed this approach to be useful in the studying of zones of faults' active dynamic action. The distribution of various endogenous and exogenous parameters within these zones is considered, and the most informative parameters are determined for normal faults and strike-slips.

The application of stochastic functions theory and statistic analysis to sea bottom depths data processing is discussed. Spectral methods were used for the analysis of morphometric data of the Middle - Atlantic ridge. The approach is shown to be applicable to geomorphologic and tectonic zoning of the ridge.

The upper plateaus of Crimean mountains lie at height of 900-1500 m. The structural grounds were found at these plateaus. They have rounded, polygonal, stripped, reticulated pattern, are covered with limestone cobble and are surrounded by «bunches» of sedge. They are formed in the areas of the wet blackearth-like loamy soils less than 20 cm thick which lie on the fissured limestone and are exposed to multifold freezing-thawing cycles.

Interconnections between soil erosion at croplands, gully solid flow and sediment load in the rivers at the central part of the Russian Plain were analyzed. On the base of cartographic data the quantity evaluations of land-loss modulus, gullies formation rates, sediment runoff as well as the estimate of correlation between them have been obtained.

The exploration of the non-metallic pits in the channel of Belaya river during several decades has caused the significant enlargement of alluvium coarseness in the lower stream. The influence of the draggers is less marked.

Mechanisms of gullies head growth in the humid zone are various and complicated. Besides erosion mechanism there are suffusion, rival, landslide and karst ones. In the dry year the contribution of erosion mechanism is little and the suffusion type of development is predominant, especially in the sandy loam, loam and loess deposits. The examples of different mechanism manifestations in the Kaluga and Bryansk districts are given.

Lateral deformations of middle Amur are under consideration. The river valley in the middle flow subsequently crosses Amur-Zeya plain, offsets of Lesser Hingan ridge and Middle Amur lowland. The river banks consisted of unconsolidated sediments within the plain and lowland are being washed at a rate up to 5 mm/y. As a result the smoothed changes of river channel occurs within the range of wide flood-plain. When crossing Lesse Hingan the channel becomes embedded and the flood-plain disappears. The characteristic period of the channel's changes is of geologic time-scale. The dependence of the river bank erosion from the vertical deformations of channel, its slope, Amur's water run-off, sediment load, coarseness of suspended sediments and human activity is revealed.

Some authors describe large gravitational paleoseismodislocations in the Dukchinskie mountains. The detailed investigations in this area have shown these objects to be the typical manifestations of the glacial morphogenesis - they are glacial bars of Late Pleistocene glaciation and have nothing in common with gravitational paleoseismodislocations. The main diagnostic features of the latter forms were determined; they can help to distinguish these forms reliably from the similar exogenous landforms.

The Tunka rift consists of several Baikal type basins and low mountain ridges separated them. Tunka rift is edged by alpine Tonka Goltsy and Olkha low tableland from the north and by Siberian-type mountains of the Western Khamar-Daban with the large volcanic plateau - from the south. The rift has a full set of morphologic elements typical for the dry rift vallyes in the south of East Siberia, these elements are represented in their normal form. Therefore the Tunka rift may be considered as a morphotype of this type of rift basins. The relief of the rift and adjacent mountains may be divided into five belts: belt of plains and belt of tilted piedmonts within the rift valley, apical belt, belt of slopes and belt of valleys' bottoms within its mountain frame. In addition there are large group of interzonal landforms.

XXV Plenary Session of Commission on Geomorphology of RAS

15th Plenary Session of the High School Scientific Board on the problem of erosion, channel and river mouth's processes at MSU

To the memory of Alexey lvanovitch Spiridonov

To the memory of Lev Georgievitch Nikiforov