Рассматриваются основные положения современной климатической геоморфологии, возникновение которой связано, прежде всего, с дифференциацией обширной гумидной зоны на ряд климато-геоморфологических зон, каждая из которых характеризуется своим типом экзогенного морфогенеза. Смена климатов ведет к перестройке рельефа, в ходе которой длительное время могут сохраняться геоморфологическое реликты климатов прошлого. Рельеф земной поверхности представляет собой сочетание поверхностей и форм, возникших в различных климатах мезозоя-кайнозоя. Сделана попытка оценки основных геоморфологических концепций с позиций климатической геоморфологии.

На основании палеогеоморфологического анализа и обобщения материалов бурения восстановлены рельеф и особенности речной сети с ее главной артерией – Палео-Волгой, существовавшие в предакчагыльский этап континентального развития в пределах Северного Прикаспия. В это время здесь располагалась обширная бессточная впадина сложной конфигурации, с озеровидным бассейном в центре. В северную часть этого бассейна открывались палеодолины Волги, Урала, Большого и Малого Узеней. Основные черты предакчагыльской и современной морфоструктуры находятся в тесной связи с глубинным строением. Выявленные палеогеоморфологические и палеоморфоструктурные особенности Северного Прикаспия имеют значение для поисков нефти и газа.

В статье приводится понимание основных задач и содержания геоморфологии разными исследователями. На основании критического рассмотрения этих взглядов предлагается новое определение геоморфологии, его обоснование и перечень входящих в нее разделов.

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.

Международный симпозиум по применению теории и методов морфоструктурного анализа при поисках минеральных и энергетических ресурсов

Вопросы геоморфологии на XXIII международном географическом конгрессе