Development of geomorphological concepts of Yu. A. Meshcheryakov in the modern geomorphology

A close connection between erosion and alluviation is a matter of common knowledge. Little is known, however, on the mechanism which binds the mutually excluding trends into a dialectically undivided process, the known f act being thus of no theoretical nor practical use. Mutual penetration of the incompatible trends results in spontaneous activation of the opposite processes (erosion and alluviation). A process goes up to certain limit and on having reached it assumes inverse direction - which accounts for the «spontaneous evolution» and «self-regulation» phenomena.

Geointormation systems application opens new prospects in the geomorphological analysis and mapping. A global digital data base on the relief designed for the geoinformation systems may be formed using the new World Hypsometric Map (scale 1:15 000 000). As an example of this data base usage, morphometric characteristics of southern continents (Africa, South America, Australia, Antarctic) are computed and discussed. The continents' area, volume, mean height as well as area and volumes of individual altitudinal steps were calculated in the automatic regime within the geographic and geological-geophysical boundaries of the continents.

A method of reconstruction of paleobasins depth is developed based on integrated results of analysis facies, thickness and pattern of stratification, taking into consideration specific features of carbonates and salts accumulation. As an example, carbonate - saline series of the Vendian - Cambrian age within the Siberian platform is considered.

A position of the hypsometric map is discussed within the system of geomorphological mapping; it is considered to be a special geomorphological map. To obtain an authentic picture of topography on the hypsometric map, the original topographic map requires revision, and the smaller is the scale, the more essential corrections are needed. Methods of such corrections are suggested, and examples are given of color hypsometric scales for different types of topography.

Stationary and semistationary observations of main erosional processes (fluvial erosion, various kinds of surf ace wash, creep and chemical erosion) have been carried out for 10 years using a new technique developed in the Problem Laboratory of Soil Erosion and Channel Processes, Moscow State University. The observation results permit to establish a significance of individual process in slope development and in the evolution of the NW Caucasus relief a whole. Relative significance of each agent of the short-distance transport in the denudation and slopes evolution is discussed with special reference to the Bzugu river basin which is a typical small catchment of the region.

Studies of marginal features in the south-eastern Kola Peninsula provided evidences that the eastern part of the northern Terskiye Keivy complex began to form between the Ponoi ice dome and the White Sea ice lobe, and later developed along the latter's margin. The process most probably took place during the whole Oldest Dryas stage. The second marginal belt (situated further to the south) was formed also by the ice lobe which flowed along the White Sea basin, but is attributed to the Older Dryas. Therefore for the first time the data are obtained which clearly indicate marginal features corresponding to the Luga and Neva glacial stages to be formed in the Kola Peninsula.

Results are discussed of channel processes studies in Western Georgia. The channels dynamics and morphology are found to depend on the land altitude and slope which accounts for a distinct altitudinal zonality of the channel-forming activity of streams. Channel processes influence considerably the coastal zone dynamics.

Investigations of the ancient and recent continental slope of the Black Sea basin revealed sedimentary layers to be truncated in some sections. The thickness of the layers removed reaches a few kilometers within the Gudauty region. The authors believe the truncation results from erosive action of slumping sediments. The theory of continental slope erosion by moving sediments is developed as a modification of the general theory of erosional processes. The slumping sediment about 13 cm thick is shown to erode the slope if the latter is composed of clay. An equation is obtained which defines the process of continental slope erosion by sediments.

Hydrological and morphological criteria are established to distinguish straight unbraided channels from meandering and braided ones. Straight channels are shown to occupy a certain position within the channel forms hierarchy, and good grounds are given for including them into the morphodynamic classification as a specific type of channels.

The Penzhinskaya Guba (bay in the north of the Sea of Okhotsk) is distinguished from other seas of the USSR by the highest tides (up to 14 m). Geological and geophysical studies identified the main process in its morpholithodynamics to be powerful continuous evacuation of terrigenous material from the coast offshore (onto the outer shelf). The size of particles transported varies in wide limits (from silt and clay to gravel) due to high activity of waves and tides. The material is evacuated mostly through the western part of the bay by a complicated system of sediment flows. Various depositional and erosional features are formed in the process, including submarine ridges and barriers up to 22 m high and erosional furrows up to 105 m deep.

The analysis of surface morphology, geological structure and relief evolution provided evidences for the meteoritic impact origin of the Zhamanshin crater in Aktyubinsk region, Northern Kazakhstan. The crater's diameter is 5.5 to 6 km, the depth up to 200 m. Geomorphological and geological data indicate the crater was formed at the end of the Early Pleistocene.

As distinct from the Geomorphological map of the European USSR, scale 1: 2 500 000, published in 1966, the new geomorphological map of the same area based on an analytic legend which shows topographic elements and landforms and specifies their age and genesis (and not morphological complexes). The map clearly displays the relief history and evolution, and geomorphic structure resulted from endogenic and exogenic factors interplay, and the recent dynamics of the topography. The map may be used in education as well as applied to solving scientific and practical tasks.

Stages in the relief evolution of the southern Koryak Highland have been elucidated as a result of structural-geomorphological investigation and sediments studies of the Khakhinan Ridge. Four stages of the relief differentiation and planation have been identified (Early, Middle and l.ate Miocene and Pliocene - Early Pleistocene) as well as the Quaternary cycle of active development of the relief. 6 Stages of general uplift and fluvial erosion are distinguished within the latter. Principal stages of placers formation are also identified.

Erosion processes studies in the Laboratory of Experimental geomorphology, Louvain University, Belgium

Urban geomorphology of arid regions - R.U. Cooke, D.Brunsden, J.C. Doornkamp, D.K.C. Jones. Urban geomorphology in Drylands. Oxford University Press. N. Y., 1982. Repr. 1985. 324 p.

On methods of regional hypsometric analysis of metal ore distribution