The author disagrees with L. King's opinion on the most widespread «Australian» planation surface being of Early Cenozoic age. The «Australian» surf ace was formed in Late Jurassic-Early Cretaceous, remnants of the Middle Triassic surface are above it and Middle Eocenic and Miocenic erosional and aggradational surfaces are situated at lower levels (within area of loose Mesozoic and Cenozoic sediments). Number and age of the planation surf aces in Australia correspond to those in Europe and Asia, the fact is accounted for by the connection of global eustatic ocean transgressions with planationsurface formation.

Problems of systematization of litho-cryogenic processes and phenomena are dealt with, a new multistage classification is introduced, as well as new classifications of individual types, taking into account a number of quantitative and qualitative parameters. A new method of construction of general classification schemes is used, which allows to change them readily into several special classifications based on any of qualitative attributes. The stated principles and methods of classification may be applied to a number of geological and geomorphological processes and phenomena.

Special features of the Central Kodry topography and main stages of its evolution are discussed. An outstanding part in the present day topography modeling belongs to landslides, especially to large erosional-landslide hollows at valleys heads - so called «gyrtops». The morphology of the «gyrtops» and its cinnection with geological structures are discussed in details. Three main stages in the present relief evolution of the Kodry are distinguished on the basis of complex paleo-geomorphological and paleo-geographical analysis. Most active landslides are supposed to correspond to cold stage and periglacial conditions during last glaciation; the present day activization of landslides is accounted for by human activity.

In middle mountains with dissected topography when erosion opens metalliferous deposits it can be easily traced by geomorphic levels, fixing changes in spatial relations of valleys to metal sources. Most important tasks of special geomorphological analysis are discussed using as a case study the Ippata-Merek region (Bureya Ridge) with tin-tungsten ores. The tasks are defines as follows: to study primary ore-bearing rocks in relation to paleo-surfaces of different age, to distinguish stages of erosion, to define manifestations of hypogenous zonation of ore-bearing rocks in the placers composition and location.

A special approach to estimation of efficiency of detailed structural-geomorphological studies is developed. The efficiency is estimated using three criteria: 1) coincidence of the structures revealed by the studies with tho.se known from geological data, 2) time which is necessary for the results, 3) cost of studies.

First criterion is based on the percentage of the structures confirmed by geological data as well as on the reliability of final results. Duration of the work decreases as its main part is done in laboratory and new data on neotectonics of region are promptly used. The total cost of detailed .structural-geomorphological work is estimated as well as cost of 1 km² of survey. Special aerial photos usage can produce a considerable economic effect.

Two large and complicated morphostructural areas can be recognized both at the shelf .and at the land within the zone of contact between the Black Sea basin and the North-Western Caucasus: Tamar and Novorossiysk areas. The areas differed from each other in morphostructures characteristics, direction and rate of neotectonic movements throughout the Neotectonic stage. Morphostructural analysis allowed to distinguish within the areas morphostructural regions and individual morphostructures differing in neotectonic movements intensity. The most pronounced features of the areas' topography were formed during last (Neogene-Quaternary) stage, characterized with considerable sinking of the basin along fault lines and its enlargement on account of middle masses of the Alpine geosyncline.

The role of the bedrock topography in the distribution of the Pleistocene deposits within the range of the insular heights is analyzed, the age of Haanja and Otepaa bedrock elevations being defined. Conclusion is drawn that the tectonic movements were not of great importance in the formation of the insular heights and the latter were formed on the bedrock cores between glacier lobes which differed in the rate of ice flow. Thus the bedrock topography was of primary significance, it predetermined debris accumulation both at its proximal and distal slopes under the moving glacier.

The author calculated thickness of average layer removed by erosion per year on the basis of solid discharge data; the thickness appeared to be more at middle` mountains of Calcareous Daghestan than at high mountains of Schistous Daghestan. It is accounted for by deep valleys and intensive weathering at Calcareous Daghestan. Considering the results the author thinks it possible that the direct correlation of erosion intensity with height (postulated by A. Penck) can be in some cases essentially disturbed.

A geomorphological scheme of the shelf of the North-East Black Sea has been compiled, showing submarine terraces, «marginal bar» or system of bars and the shelf's edge. Analysis of the present-day abrasion processes allows concluding that the terraces are regularly formed at depths less than 20 meters and more than 60 to 70 meters. A simple mathematical model of shelf evolution is introduced.

The author argues the necessity to take into account a correction for the World Ocean level change when total neotectonic movement amplitudes are calculated or neotectonic maps are compiled. The correction (when used on the scale of the whole planet) is shown to increase considerably the areas submerged during the neotectonic stage, which confirm the well-known hypothesis of progressive contraction of the Earth.

Geomorphic processes change the surface topography, and the changes themselves induce decrease or increase in the processes intensity. Thus the auto-regulation of the forming relief is manifested through the intricate interaction. Stage of erosion can be defined by the character of real surface, using a dissection index which can be easily' calculated from topographic maps.

The Vagai valley cuts three basin terraces of different age. There are II local fluvial terraces within lower reaches of the valley (150 km long) which are associated with the three basin terraces levels and the Irtysh River terraces. The valley is proved to consist of three section differing in age, their limits are basin shorelines 110 and 75-80 meters high, corresponding to two transgressions maxima. The floodplains are also of different age. The terraces are considered to be eustatic. Their typical features are association with a certain basin terrace, local extent, relative lowering upstream to the first terrace level, each terrace disappears approximately at the height of the upper limit of the next (higher) basin terrace.

The author describes the mechanism of expiration (glacial erosion) at the sea floor by Shelf glaciers, the latters differing in mass budget (Ross glacier freezes and melts at its base, McMurdo glacier actively freezes at the base). The expiration rate is calculated to be not less than 1 cm per year at loose sediments and 1,0 to 1,5 mm per year at rock floor. Typical features of expiration topography are stated, which has been formed by shelf glaciers and emerged due to tectonic uplift of the Transantarctic Mountains (sub-horizontal expiration terraces, crossing flatbottomed valleys, now situated above mountain glaciers surface). A classification is developed of loose deposits- formed by shelf glaciers.

A detailed structural-geomorphological analysis of coastal plains and shelf at East; Arctic sector of the USSR allows to distinguish four group of structures, including: archdome uplifts inherited from late erogenous stage, structures due to differentiated down-warping of the shelf; block structures at the zone of shear stress; rift structures. The delineated system of circumpolar faults shows similarity of submerged and emerged parts of the arctic margin of the continent, the system itself being a structure of planetary rank. Its special features and contacts with more ancient continental structures indicate that besides the shelf down-warping lateral shear movements were of importance.

Into the group of rock solifluctional forms the author includes stone steps, garlands, tongues and some transitional forms. The structure, distribution, conditions and mechanism of evolution of the forms are described. A single genetic sequence is -shown: stone polygons-stone steps and garlands-stone tongues--turf-covered solifluction tongues.

Soil erosion and channel processes (geomorphological aspects of the problem)

A.P. Rozdestvensky (to the 60th birthday)