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Геоморфология

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№ 4 (2008)

Общетеоретические статьи

3-16 242
Аннотация
The investigations of erosion in various landscape zones of the Earth's plains prove the existence of two basic systems of erosion: the channel and the basin ones. The principle distinctions of these systems show itself in structure of erosion processes and accumulation of their products, in hydrological regime of rivers, in character of dependence of specific suspended sediment yield on river basin area, in structure and thickness of alluvium, in relation between alluvium and slope sediments, in dynamics of river channels, in some features of river valleys morphology, in degree of preservation of relic landforms in the river basin, in general tendency of relief development (valley partition or planation), in intensity of sediment accumulation within the river channels and the flood-plains, ponds, and reservoir, etc. The present river channel system of erosion is divided into two subsystems: one of humid and semi-humid moderate latitudes and one of humid and semi-humid tropical and equatorial latitudes. The present basin system of erosion is also divided into two subsystems: anthropogenic one and natural (semi-desert, savanna, and sub-arctic zones) one.
17-28 277
Аннотация
Functioning of the two main systems of erosion in the plain river basins, geomorphologic results of their activity and changes are not the characteristics of recent period only, but are typical for Pleistocene also. Alluvial deposits, formed during epochs of channel systems domination, fill the erosion hollows and have normal thickness, well-defined stratification at separate facies; slope deposits cover is cut off near valley flanges. Morphogenic and lithogenic processes were concentrated in the river valley bottoms, while slopes and watersheds represented to quite steady formations. Alluvial deposits formed during epochs of basin systems domination had wider distribution, increased thickness, and often were facially replaced by slope deposits near valley flanges. Relic landforms and surfaces of such epochs indicate intensive relief reorganization. Temporal changes of erosion systems have resulted in binary structure of river terraces in all valleys of the east (extra-glacial) part of the Russian Plain. The bottom alluvial series correspond to phases of predominant cutting (river channel system), top series correspond to predominant accumulation (basin system).

Геоморфология и народное хозяйство

29-34 215
Аннотация
Metalliferous blocks within ore-bearing region are characterized by maximum absolute and relative heights, high degree of dissection. Ore indications and ore deposits are located at several height levels in such blocks. According to these characteristics perspective metalliferous blocks were revealed in the Badgal'sky ore district, which shows the possibility of block analysis of morphostructure in ore prospecting.
35-47 320
Аннотация
An approach to classification of alluvial gold placers by their formation dynamics is put forward. Alluvial gold placers formed during different dynamic stages of river valley formation - erosion, abrasion (lateral erosion), equilibrium, and accumulation ones - differ by their composition, structure, orientation in the valley bottom, correlation with the valley surface and bottom relief. Such placers occur predominantly in valleys of different size and within the range of different morphostructures.
48-54 216
Аннотация
On the example of Nimansky gold-bearing region it was shown that the gold grains size depends on the depth of erosion dissection in case the original loads and climate conditions being of the same type within the metallogenic province. The largest grains are concentrated in those parts of river valleys, which are about 320-420 m in depth, the smallest ones - in the valleys about 160-240 m in depth. The valleys with the depth less then 120 m and more then 420 m have no commercial deposits.

Научные сообщения

55-64 282
Аннотация
The paper shows the possibility of using the largest seismically induced paleolandslides for estimation of magnitude of generative earthquake, total volume of displaced material, and the contribution of seismically induced landslides to erosion. This approach is independent one in the context of traditional paleoseismological method. It may significantly improve the results of seismotectonic dislocations study and is an alternative method in case of bad preservation or absence of such dislocations. The method was tested in epicentral zone of Chuya eatrthquake (SE Altai).
65-74 194
Аннотация
To estimate the direction and rate of vertical riverbed deformations the curves of regression were obtained for rivers' level and discharge. The longitudinal profiles of some rivers were plotted. The predominant type of profiles is concave one, which relates to growth of discharge and decrease of gradient downstream. The bed with well-developed alluvial forms is incidental to all rivers with water surface slope less then 20%. The middle and lower streams of the rivers in the zones transient from mountains to basins and littoral plains may be considered as mountain rivers. In volcanic areas equilibrium river profile should be calculated taking into account the density of incoming piroclastic material.
75-82 191
Аннотация
Morpholithogenic processes which formed relief of Ust'-Kanskaya and Yaboganskaya basins during late Neopleistocene are described. The existence of paleolake formed by the ice dam in the early Wurm near Ust'-Kan village was proved. Glacial dislocations accompany the moraine deposits. There are geologic evidence of mudflows and massive floods on the slope down the lake. During the middle and late Wurm eolian processes and paedogenesis were active. Tectonic movements took place in the second half of the Neopleistocene.
83-91 223
Аннотация
Ol'khon block have steps of 350-600, 600-800, 800-1200 m height, Priol'khonsky block have steps of 350-560, 560-600, 600-680, 680-800, 800-1000 m height. These blocks are the dry part of closing dike between Northern and Middle Baikal depressions. The structure of relief is determined by paleoforms of denudation relief, which have persisted since the formation of the oldest (late Cretaceous - Paleogene) transregional and younger (Pliocene) planation surfaces. Since that time no considerable relief transformation have taken place.
91-101 179
Аннотация
The bed off the Votkinsk (Kama river) reservoir dam reach is leveling on the whole. Intensive wash out is predominant at low and middle depth. Some bottom elevations were lowered by 1-2 m during 15 years. Material is transported into deep water - more than 6-8 m. Maximum thickness of accumulated deposits reaches up to 5 m, while average values are about 1.1-1.5 m. Facial composition of deposits depends on hydrologic factors: unstable level of reservoir, frequency and strength of storms, ephemeral and perennial currents.

Рецензии

102-103 186
Аннотация
Рецензия на книгу Э.А. Лихачёвой “Экологические хроники Москвы”
103-105 202
Аннотация
Рецензия на книгу "Эстуарно-дельтовые системы России и Китая: гидролого-морфологические процессы, геоморфология и прогноз развития".


ISSN 0435-4281 (Print)