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Geomorfologiya i Paleogeografiya

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No 4 (1986)
3-14 68
Abstract

Morphostructural evolution of inter-plate - sutural - zones is discussed, island arcs and mountain uplifts being co-pared and likeliness and differences in their evolution being traced for 3 stages i. e. Pre-Late Mesozoic, Late Mesozoic-Early Cenozoic and Late Cenozoic. The two zones developed in similar way at the first stage, difference first appeared at the second stage and considerally deepened at the third. Island arcs evolution proceeds in cycles mostly under oceanic conditions, erogenous uplifts grow continually mostly within limits of the continents. Both kinds of sutural zones are characterized by migration of 'slald arcs replaced by erogenous structures from Eurasian continent towards Pacific and Indian oceans linear block morphostructures to replace microcontinents, mantle and folded arcuate structures to be formed at the places of deep troughs marked by ophiolitic belts.

15-23 87
Abstract

The history of topographic evolution is analysed with reference to SW Transbaikalian region, Sikhote-Alin and Tukuringra-Iagdy ridges. Geological and geophysical data obtained give no ground for considering of the regional orogenesis within the frame of mobilistic theory. The main cause of the orogenesis here is thought to be subvertical migration of the upper mantle matter along deep fractures, granitisation and the earthcrust density reduction due to heat and mass transfer, thickening and deepening of «mountain roots» which result in isostatic uplift of the mountains. However the author thinks it real enough the two lithospheric plates (geoblocks) to have collided in the Mongol-Okhotsk sutural zone; Tukuringra-Jagdy horst was formed as Amur and Aldan-Stanovoi geoblocks were brought together.

Discussions

Geomorphology and economy

31-36 97
Abstract

Wind erosion processes in the region under study are favoured by a complicated wind regime, low quantity of precipitations, and predominance of loose sands. Measurements showed the sand landforms migrate mostly southward, some seasonal migration westward and eastward were also observed. Sand surf ace consolidation was attempted using water solution of sulphate-alcohol distillery refuse with addition of suspension polyvinylacetat. The tixativc expenditure is about 2 l per sq. m. Wind-blown sands may be also fixed by Caligorzurn aphyllum or C. junceum.

37-45 88
Abstract

Methods are developed for engineering-geomorphological analysis of faults with view to conditions of tunneling. The methods are based on using space images of various scales together with morphometric analysis of topographic maps, the data being specified in the course of field engineering-geomorphological studies. The methods were put into practice to estimate fault zones along the tunnels of the Caucasian railroad.

46-50 82
Abstract

The topography is factor controlling the hypergene mineral deposits formation, though often underestimated in geological search practice. The underestimation leads to questionable reconstructions of topographic elements which enclose the deposits. Problems of evolution, stability and conservation of ore-bearing topography are still insufficiently studied. To increase the mineral search efficiency it is necessary to work out the typisation of geomorphic environments for individual metal-bearing provinces and regions on the single morphogenetic basis, the typisation should take into consideration the substrate metallogeny and elucidate the problems of geomorphic environments evolution during the ore formation and subsequent stages.

Scientific Research Methods

51-57 83
Abstract

Methods, theory and practical aspects of aerial remote sounding data analytical interpretation are considered as applied to quantitative data gathering on river channel and floodplain morphometry. Photogrammetrical approaches to channel process study are shown to be effective. Experiments results are in good agreement with nature studies data.

58-64 74
Abstract

Long term stationary studies aimed for denudation processes investigation at NW Caucasus and based on repeated photo-theodolite survey appeared to be promising for forecasting and calculation of the denudation volume. Twenty years period of observation indicates the necessity to consider the chronological position of the observation interval with respect to phases of periodical humidity changes. Most precise and representative data on background and extreme intensity of present-day exogenous processes are provided by regular observations, long enough to embrace at least two phases of humidity cycle.

Short communications

65-69 72
Abstract

Linear elements of erosional landforms of surficial and bur'ed topography were analysed and compared with fault-lines pattern, the author concludes that the adey network of the region was mostly inherited from previous stages aztec developed along fault-lines.

69-75 75
Abstract

On the basis of the flows plan drawing a technique is introduced which permits to calculate the flow kinetic energy, transporting capacity and bed load discharge in braided channels, the calculations being made for various types of channel furcation of the Lena River. The equalization process is most pronounced in complicated (morphologically) ramifications. Considering one of the branches, the kinetic energy increases where the flow skirts islands and point bars, however the bed load discharge does not necessarily increase. The kinetic energy changes depend on the changes in the flow pattern and channel bed relief.

75-78 66
Abstract

The algorithm and program «Relief» are discussed which aimed for identification of regional and local components in the surface topography, the technique had been tested at the west Caucasian foreland. Tlle efficiency of the geomorphological study using computer is shown as applied to structural-tectonic investigation of oil and gas bearing regions.

78-87 68
Abstract

General trends of mountain Fergana paleoreliei evolution during Late Paleozoic - Early Mesozoic are considered, Jurassic karst topography formation is analysed in detail, in particular typical cone and tower karst landforms and some associated forms such as erosional karst plains and niches at hills' base due to corrosion and gravitational processes. The mentioned landforms of ancient karst are considered to serve as -datum levels as well as indicators of morphostructures position when carrying out morphostructural analysis of mountain regions.

Chronicle

88-90 68
Abstract

Trends in geological-geomorphological study of the World Ocean (All-Union School on Marine Geology, 1986)

Anniversaries

 
91-92 96
Abstract

Nikolay Ivanovich Nikolaev (to the 80th birthday)



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