Coastal barriers are widespread marine accumulative forms, which often exist as barrier islands. Causes and conditions of coastal barriers formation are under consideration. According to authors their origin relates to transgressive reconstruction of coastal zone. They appear only at the water edge and on the condition when slope of coastal land and offshore slope are in certain relation. The formation of submarine bars and their consequent appearance above water level are impossible.
Multichanneled river bed appears when sediment load from the upper basin exceeds carrying capacity of the river in the site. Meanders appear on the converse condition. If the sediment load equals carrying capacity in the straight channel the latter continues straight (bandy-ridged).
The data base structure, investigation principles and ecogeomorphologic criteria of urban territory evaluation are suggested.
Discussions
Active faults as risk factor of geomoiphological processes (on the problem and on the -paper of S.B. Kuzmin)
The replication to A'.A. Nikonov's comments - Active faults as risk factor of geomoiphological processes (on the problem and on the -paper of S.B. Kuzmin)
The discussion may be continued (Nikonov A.A. Active faults as risk factor of geomoiphological processes (on the problem and on the -paper of S.B. Kuzmin); Kuzmin S.B. The replication to A'.A. Nikonov's comments)
Themes of paper by V.V. Bronguleyev at al. (Geomorphology 2, 1998) are under consideration. Author emphasizes that not all of lineaments on the platforms are the faults. By the most part they are landscape-geomorphic manifestation of planetary jointing. Very strong reasons are obligatory to distinguish real fault. It is necessary to distinguish the zones Of stress concentration and geodynamic activity on the platforms.
Scientific Research Methods
The results of the experimental study of the interrelation between geomorphological features and multiscaling behaviour of lineament nets in the scales 1:250000 and 1:500000 are presented. The scaling of fledg-faults was found to be the most indicative parameter for the intensity of neotectonic movements. The multiscaling study of lineament nets is considered to be an effective new tool for cartometric analysis of spatial morphological structure of the relief and for the estimation of neotectonic and possibly seismic activity.
The method of estimation of existing and potential dissection is presented. The method is applied to European part of Russia for valley-balka and gully network. The average slope length of erosion network is taken as the main parameter. Mapping of this parameter allows to evaluate the hazard of gully erosion and to distinguish regions of recent environmental tension.
Short communications
Paleoclimatic reconstructions and relief analysis were fulfilled, using the large-scale topographic maps and space images for the land and bathymetric and seismic data - two types of mountain and valley glaciers of different thickness and activity were distinguished in the region for the Late Valdai Age. Paleoclimatic and geomorphologic data indicate the absence of continuous thick ice cover on the Pechora lowland during this time.
The conception of the aeolian accumulation growth during transgressions is critically discussed. Dunes formation is shown to be under strong impact of the morpho- and lithodynamics of the offshore and beach under the condition of relative sea level changes. On the basis of composition and texture analysis of Littorina key section in the Liepaya bar (East Baltic) the model of high dunes formation was developed. Stabilization of sea level during regression conduces to the appearance and the grouping of coastal dunes. If the ingression takes place, reactivation of previously formed dune ridges happens during the stages when sea level is stabile or decreasing.
Simple classification of elements of gully-balka (dry valley) systems is put forth. The classification combines ranked nomenclature with morphometric and dynamic characteristics. Six types of elements were distinguished, they are considered as generic. These elements may be separated by the morphology of their longitudinal and transverse sections. The scheme of gully-balka lithogenesis was compiled; it shows the trend in the development of gully-balka systems as well as acceleration and deceleration of this development.
On the basis of alluvial heavy fraction analysis and long-term stationary observations of channel landforms movements the high stability of landforms was revealed in the stretches of straight or meandering river channel. This may be explained by silt dynamics within the strict frames of erosional relief of valley's bedrock. The lateral deformations of channel landforms and movements of accumulation and erosion sites occur in the places of branchy channel. Anabranches are the ways of bed load transport, where exchange of moving sediment and one accumulated in the channel forms takes place.
Loess rocks are widespread on the Earth. They occupy about l0% of global land area. Their thickness reaches up to 300 m in places and even more. Loess rocks differ in the different parts of the Earth. The "warm" and the "cold" loess rocks may be distinguished. They differ not only by conditions of their formation: the "warm" loess rocks are older. The age of oldest loess according to magnetostratiraphic data is about 3.5 My. The accumulation rate of fine earth was estimated by paleomagnetic dating. Paleomagnetic method gives manifold possibilities for paleoclimate reconstructions.
Anniversaries
Reviews
Hydrosphere history through the prism of geologic-geomorphologic development of the Earth
Monograph of V.G. Chuvardinsky «On the glacial theory»
Potpourri of antiglacializm
Chronicle
Third International Symposium on Geology of Turkey: impressions
XXIV plenary session of Geomorphologic Commission of RAS
Association of geomorphologists of Russia: first steps
ISSN 2949-1797 (Online)
