Preview

Geomorfologiya i Paleogeografiya

Advanced search
No 1 (2015)

Articles

3-13 2989
Abstract

Analysis of QI–diagrams and earlier obtained results demonstrates that in the territory discussed, the braided rivers constitute a statistically homogeneous population in the whole range of drainage areas considered (15–100,000 km2). Inside this population, rivers depositing alluvium differ from rivers at equilibrium (having the same mean annual floods) by higher valley gradients. Incising rivers often have similar or even lower gradients as compared to braided rivers. In the basins’ upper reaches, meandering streams are fairly numerous. Their valleys, all other conditions being equal, have lower gradients, compared with braided rivers, by a factor of 1.5–3.2. Presumably, they are a product of degradation of braided rivers.

14-21 2096
Abstract

The further development of the N.I. Makkaveyev’s theory of the united erosion-deposition process and the synthesis of the concept of this process manifestation at different parts of the fluvial systems (FS) is proposed. Such a synthesis was developed on the basis of the equation of sediment budget, which is universal and basic for all types of FS on different scales. The ratios of the values of the main terms in this equation: erosion, deposition and sediment flux from the catchment, are the explicit quantitative criteria for classification of the parts of FS and of their definition as erosional, dynamically stable or depositional, according to the sign of the sediment budget. It is proposed to define the overall FS type, from the head waters to a given cross-section, according to the delivery ratio.

Discussions

22-35 1673
Abstract

The existing views on the physical conditions of cryogenic heave of grounds are discussed. It is shown that it is necessary to clearly distinguish between two types of ground systems: closed and open. For the closed systems the accepted models are physically correct. However, they are not suitable for the open systems. The positive landforms of cryogenic heaving can rise by the Archimedean force due to the density difference between the thawed and frozen ground. Such a mechanism of swelling, considering the nature of the substrate in which it realizes, can be called lithostatic. The author worked out a theoretical framework including some mathematical assessments of the lithostatic mechanism. The appropriateness of the lithostatical concept is proved by the author's experiments, as well as by the actual data of other researchers. Lithostatic concept makes clear a number of peculiarities of cryogenic swellings, which previously had no strict physical explanation. Using thе lithostatic concept for the explanation of various phenomena in the formation of the forms of cryogenic relief could be useful both in scientific, and in practical terms.

Ecological and Applied Geomorphology

36-40 818
Abstract

The gold release from ores and rear-ore and rear-ore rocks into fine earts (melkozem) among kurums in mountain deeply dismembered area of Transbaikalia occurs more intensely on slopes of southern exposures than those of northern ones. Respectively, interkurum contrastive lithochemical gold anomalies form much more often on the southern slopes. If they are significant in the area measurements, it is advisable to use the considered factor to justify primary evaluation of the object to a depth as of possibly bulk one with relatively low contents of gold, but large ore mass.

Short communications

41-47 759
Abstract

The typology and spatial mapping of ecological-geomorphologic systems of the North-Eastern Caucasus are firstly presented. They are characterized by the unity of the geological-geomorphological and anthropogenic conditions and arising geo-ecological situations.

A comparison the types of ecological-geomorphologic systems on the degree of anthropogenic load and indicators of intensity of ecological-economic conditions of the territories allowed to reveal differences geo-ecological situations in the most developed and industrialized regions of North-East Caucasus. Calculated indexes geo-ecological sustainability for each type of ecological-geomorphologic system are compared. The highest index in the highland and lowland types - the territories of forest and meadow lands. The lowest indexes of stability are obtained for the lowland type, almost devoid of greenery.

The method of scoring in midland and mountainous types of ecological-geomorphologic systems it is demonstrated the prevalence exogeodynamic processes, which are related not only with natural, but anthropogenic factors, including avalanches, landslides, mudflows, seismicity and other. Not so much these processes are expressed in areas that are attributable to the low mountain and lowland. But as a result of considerable anthropogenic pressure (mainly on land resources) there are high levels of absolute and relative tension ecological-economic conditions of the territory.

48-53 995
Abstract

The Crimean coasts are considered as the sum of coastal morphosystems. Their marine and overland borders have been determined. Overland borders are watersheds of rivers (1-4 orders), marine borders are in most cases30 metersisobaths. The specialties of structure and functioning of coastal systems have been detected as well as their regional differences. For instance, the area of the Western Crimea’s coastal systems much larger than South Coast’s ones. As a rule, the BMS Crimean coastal morphosystems includes part of the water area and 10-15 river basins of various ranks. Key factor in the functioning of systems is the balance of sediments.

The typification according to configuration of the coasts and degree of human influence has been made. The main specialties of human impact on coastal systems have been uncovered. The types of natural resources that have the greatest impact on their functioning have been determined. This is coasts’ defence, buildings of channels and water reservoirs and agriculture.

54-69 1290
Abstract

Recent palaeolomnological studies of the small lakes sediments in the northern Karelian Isthmus have demonstrated that the start of organic (gyttja) sedimentation in the Holocene was not simultaneous due to the differences in 1) the lake's elevation, and 2) the proximity to Lake Ladoga shoreline. Organic sedimentation in the lakes located at30 ma.s.l. and higher started around 11000 cal. BP. No major changes in their hydrological conditions have been recorded hereafter. In the lowland lakes (11-20 ma.s.l.) located in the proximity of the Lake Ladoga shoreline the start of organic sedimentation has been dated to 3000-4000 cal. BP. The underlying clayey gyttja contains lower amount of organic matter (ca 10 %) and the diatom assemblages dominated by the “large-lake” diatoms typical for Lake Ladoga. Therefore, the rapid increase in organic content in the lake sediments points at the isolation from Lake Ladoga, and enables to date the termination of the Ladoga transgression to 3000-4000 cal. BP. In the lakes situated at 11-14 ma.s.l. near the present watershed between the Gulf of Finland and Lake Ladoga, gyttja accumulation commenced at 3000-4000 cal. BP. Here the organic sediments overlie unsorted sand and silt that contain “large-lake” diatom taxa. Such sedimentary succession indicates that high-energy sedimentary environments (strait or river-like outlet from Lake Ladoga) persisted in the northern Karelian Isthmus until at least 4000 cal. BP when low-energy environments established resulted from Lake Ladoga regression. Hence, the small-lakes sedimentary records provide an independent evidence for the Lake Ladoga – Baltic Sea connection through the main Ladoga outlet in the north of the Karelian Isthmus in the mid-Holocene.

70-76 1146
Abstract

The study is aimed at determination of magnitudes and directions of sediment fluxes along the coasts of Sambian Peninsula and Curonian Spit by using the calculations of wave-induced sediment transport in a coastal zone. On the base of available data on nearshore bathymetry and wave regime the distributions of both the total fluxes for main wave directions and net sediment flux are computed. It is shown that sediment transport along the studied coasts break up into a number of cells with alternating zones of divergence and convergence. Unidirectional sediment flux is traced only in the northern section of Curonian Spit (up to 260×103 m3/year). Predicted location of the erosion and accretion zones associated with changes in the net sediment flux is confirmed by the published observed data.

77-87 4909
Abstract

The article is devoted to the evaluation of the New Moscow territorial resources from the point of view of the geomorphological conditions. Analysis of the development of exogenous processes and anthropogenic transformations on the territory of New Moscow shows that almost 1/5 of its territory has certain difficulties for development, included the elimination of natural hazards and adaptation of the existing man-made infrastructure to the new tasks. It was analyzed the main regularities of relief, quantitative data on the exogenous processes on the territory of New Moscow and the degree of anthropogenic transformation. The semi-quantitative model of territory, founded on the geographically-distributed database was created. This database consists of the basic parameters of geological-geomorphological conditions and subdivided into three parts as aspects of the evaluation of relief: the cultural-aesthetic, geoecological and geotechnical. The conclusion of investigation included the thesis about necessity to found cultural and aesthetic needs of the population to the foundation of the integrated assessment for the rational use of the annexed territories. Received particular models integrated into a comprehensive model based on a combination of attractiveness of the territory for life, as a priority aspect, and related conditions of geoecological stability and geotechnical risk development. Recommendations on the directions of territorial development, including for the planned "growth points" of the New Moscow proposed.

88-100 844
Abstract

In the late Pliocene and Pleistocene onsite the Cretaceous-Paleogene peneplain peripherally the Dzungaria the high mountains occurred and the plain remained in the center as the territory of massive material accumulation which carried out of the mountains. Three main relief levels formed. Top level included high altitude, middle altitude stratum and intermountain basin stratum on the area of 146000 square kilometers. Middle and low levels formed Dzungarian plain on the area of 223,5 square kilometers. Its margin part (middle level) is represented low changed peneplain (28% of the area). Low level in central part organize the following geomorphological stratum: eolian (21%), lake (5%), alluvial-and-proluvial (21%) and stratal plain (11%), proluvial fans (10%) and front ranges – forbergs (less than 1%). Modern and ancient valleys of large streams occupied less than 3% of the plain area.

101-112 1612
Abstract

Chocolate clays are one of the most common facies of Lower Khvalynian sediments of Northern Caspian and Lower and Middle Volga region. After more than a hundred years of research, there are still a number of unresolved issues related to the conditions of its bedding, structure, facial structure and colority.

Chocolate clays are confined solely to pre-Khvalynian relief depressions: terraces, paleo down cuttings and junctions of large tributaries at river valleys, and varied in form and origin paleoravines, estuaries, saline-dome depressions (Elton Baskunchak) and ancient deflationary depressions (Kalmykia) at watersheds. Chocolate clay roofing according to the general slope of the surface of the Lower Volga and Northern Caspian gradually decreases from north to south. The highest level of occurrence of clays in the Caspian depression is usually noted at levels +20-25 m. To the north, within the valley of the Volga, clay roof rises to a level35 mand above.

There are two types of chocolate clay by the pattern of its distribution: continuous and intermittent (mosaic). Continuous distribution prevails in the Volga River valley and is observed in ancient estuaries and junctions of Volga River’s major tributaries: the Large and Little Irgiz, Large and Little Karaman, Torgun etc.

Depending on structure features facies (macrofacies) of chocolate clay are divided into subfacies: monoargillaceous, stratified, sand-clay and silt-clay. The most common monoargillaceous subfacies have total clay composition. It’s massive unstratified or hidden-stratified dark chocolate brown clay with a large block jointing, sometimes interbedded with lighter silt varieties.

History of Science

113-116 737
Abstract

Present paper states research and analysis of M.V. Piotrovskiy book about the life and artistic legacy of W.M. Davis and V. Penk. Previously this book couldn’t claim for deep review of the base geomorphological problems. However content, logic of statement, author’s continuous effort to analyze and connect the dots of previous and modern geomorphological science, to show urgency of ideas of two distinguished scientists, and also abundance of interesting facts, comparisons and references removes this book beyond the framework of customary popular scientific publication.

117-121 949
Abstract

Anuchin developed a doctrine on earth surface. He wrote a book about the land relief generally and about the Russian Plain relief in particular. He considered the land relief from progressive scientific points of view: earth surface is formed by the interaction of interior and exterior forces; polarity between land and ocean began to compose in old periods of the crust history, although land and ocean scopes mat with varied changes during geological epochs.

Anuchin gave some cases: 1) land consists of some stages – levels, at that each part of the world is characterized by its own levels variety; 2) mountain levels are advanced from equator to thirties parallels, and decreased to poles after them; 3) depending on geological structures and mountain relief denudation Anuchin divided land surface into three types – mountain, hilly and plain relief – and inside them he separated genetic forms – homotypic and geterotypic; 4) he gave the first classification of river valleys, tranches and karst forms.

Anniversaries

 
122-123 354
Abstract
To the 70th annniversary of two scientists-colleagues

Chronicle

127-128 674
Abstract

Chronicle of the IV All-Russian scientific-and-practical conference “Ecological-and-geographical researches in river basins” in Voronezh.



Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


ISSN 2949-1789 (Print)
ISSN 2949-1797 (Online)