Modern climatic geomorphology identifies 7 climatic-geomorphological zones, unlike the cycles concept by W. Davis, which divided land into 3 zones. Each zone is characterized by its own type of exogenous morphogenesis. Changes of climates induces changes of topography, though morphoclimatic relicts of previous environment are conserved for a long time. From the viewpoint of climatic geomorphology the author reviews the ideas of W. Davis, W. Penck, L. King and doctrine on morphostructure and morphosculpture of I. P. Gerasimov.

Paleogeomorphological analysis and generalization of borehole data revealed topographic features and drainage pattern, the Paleo-Volga being main artery, which existed during Pre-Akchagylian continental stage of North Caspian area development. Paleotopography reconstruction was based on usage of complex quantitative and qualitative techniques such as study of thickness, lithology, and faces features, stratigraphic completeness of overlying sediments, reconstruction of regional slope and ancient hypsometry, analysis of geological features of the surface of Pre-Akchagylian unconformity etc. A vast endorheic depression of complicated configuration was ascertained at the North Caspian area, a lake basin was situated at its central part, paleovalleys of the Volga, Ural, Big and Small Uzens were falling into the northern part of the basin. Main features of both Pre-Akcha-gylian and present morphoslructures are in close connection with deep structures. The established paleomorphological features of the North Caspian area are of importance for oil and gas prospecting.

Geomorphology is considered to be an independent branch of the Earth sciences which deals with studies on origin and development of all forms of the present-day topography, land and ocean floor, on relief-forming processes within the geological space, the processes controlling movement of mineral substance of the Earth crust and resulting in correlative deposits and landforms. Considering the trends of the science and practice development, it seems expedient to subdivide geomorphology into the following sections: analytical, general, regional, historical and planetary geomorphology, an explanation of each section being given in the text of the article.

Surfaces with slope less than 5⁰ were outlined along river valleys and at axial zones of mountain ridges using large scale maps. Adjacent fragments of the slightly inclined surfaces were put in groups, topographic steps linked by steeper slopes were noted and relicts of ancient topographyplanation surfaces were traced within certain height intervals. Most clearly they can be seen at the summit planes of ridges. Six surfaces of continuous and intermittent denudational planation have been identified, five of them corresponding to those established earlier during field geomorphological studies (tables 1, 2). Map of planation surfaces allows to show stages of topography and drainage development; it marks shifts, thrusts, grabbers, subsided and uplifted parts of mountains. Depth of erosional cut-off of ore-bearing structures can be defined.

The planation surface of the Ukrainian shield basement was formed at Aalenian (Middle Yurassic) time by processes of continental denudation under the conditions of mainly humid climate. Later on differentiated movements of the basement's blocks resulted in division of the planation surface into areas differing in altitudes. The primary Aalenian surface conserved its topography only under mantle of Middle Yurassic sediments; at other places it has been transformed by younger erosion and its age can be determined after sedimentary rocks overlying the basement.

Nevertheless, general topography of the primary surface of the basement (position of main divides and river valleys) has been conserved until now.

Lack of identity of ideas on mudflow mapping on middle and large scales is noted as maps compiled by geological organizations usually don't show hydrometeorological conditions of mudflows formation and hydrometeorological maps of mudilows show but very little of geological and geomorphological data. Purpose of mudflow hazard map at middle and large scale is discussed. A proposition is made to compile middle-scale complex maps showing conditions of mudflow formation along with maps of mudflow hazard, Mudflow maps are mainly partial special geomorphological maps of applied significance; according to their contents they belong to analytic specific maps. Main principles are developed for legend construction for all three kinds of maps.

Two main stages, i. e. Early-MiddlePliocene and Late Pliocene-Quaternary, can be identified in the course of the Transcaspian topography development on the base of paleogeographic data and structural-geomorphological analysis. The first stage was characterized with tectonic activization and predominance of enormous scale processes of arid erosion. Special feature of the second stage was spreading of water basin at considerable area and as a result wide distribution of aggradation landforms together with erosional ones.

The paper discusses principal possibilities and techniques of determination of paleodepth in basins around reefs which are now buried. Elevation of top of a reef above the basin floor may be approximated by difference between thickness of the ref and that of synchronous non-reef sediments. As the top of the reef is about sea level, its height is almost the same as the depth of the surrounding basin, Methods of studies of overlying sediments (considering different degree of their condensation) are introduced to estimate differentiated tectonic subsidence, initial pre-reef relief and the reef's sinking into underlying deposits. Cases of reconstructions of different kinds of reefs are discussed, both under conditions of differentiated subsidence and without it.

The article presents a tentative generalization of data on geomorphology of the Pinos Island, results of the authors observations included. The island topography is subdivided into morphogenetic types as follows: denudational fluvial, karstic and thalassogenic ones. The denudational relief is represented by a surface of denudational planation, which is spread over the main part of the Northern Pinos at 10-12 up to 60-70 meters a. s. l. Fluvial relief is represented .by numerous river valleys forming a radial drainage pattern. Karstic forms are developed on limestones of Southern Pinos and on marble ridges of Northern Pinos. Thalassogenic forms of relief include coastal forms and sea terraces at 2,5-6 and 10-12 meters a. s. 1. There was not established any evidences of higher sea level.

The features of the volcanic structure and distribution on the Atlantic ocean bottom based on the materials of the expedition investigations and published charts and papers are described. The volcanic processes play the main part in the forming of the seamounts and oceanic islands. The total volume of the volcanic rocks, the forms built of, is 1,4 mil. km². The formation of the submarine ridges and arch. block rises is caused by the tectonic movements but the volcanic processes play the main role in forming the basement of these morphostructures. The total volume of the volcanic rocks in the morphostructures reaches 67 mil. km².

Carried out studies proved advisability of usage of space photographs 1:1000000-1:1500000 scale for compilation of middle and large scale map, showing horizontal dissection of topography, Main index at the map is recommended to be index of dissection density q=Q/P, where Q stands for quantity of erosional forms and P - for area under study.

International symposium on application of theory and methods of morphostructural analysis for searching mineral and energetic resources

Problems of geomorphology at the XXIII International Geographical Congress