Литосфера, 1997, No.7
/ Издания академии / Научные журналы
Литосфера, 1997, No.7
Номер 7, 1997
СОДЕРЖАНИЕ
ОБЩИЕ ПРОБЛЕМЫ
Aizberg R.Ye., Aronov A.G., Garetsky R.G., Karabanov A.K., Safronov A.M.
Seismotectonics within the territory of Belarus and the Baltic States. pp. 5--18
Abstract: The main seismotectonic features revealed within Belarus and the Baltic States are represented in a seismotectonic map which forms the basis for the general seismic zoning of this region. 18 seismic and potential seismic zones where the occurrence of earthquake foci is possible (PEF) were distinguished. Dimensions of these zones were outlined taking into account the morphology and kinematics of active faults, prevailing depths to earthquake foci and maximum sizes of foci areas. The minimum possible magnitude of earthquake was calculated from the seismotectonic potential data, or accepted the actual maximum instrumentally magnitude recorded within the considered PEF zone. The Pripyat seismic superzone (Mmax = 3.5--5.0) and Minsk (Mmax = 3.7), Riga (Mmax = 3.3--4.5), West and Central Estonian (Mmax = 4.0--4.5), Osmussaari (Mmax = 4.7), Vilnius (Mmax = 4.9) and Oshmyany (Mmax = 4.5) zones, generating seismicity were distinguished with the highest confidence. The Borisov (Mmax = 4.0), Kaliningrad-Lithuanian (Mmax = 4.0), Orsha (Mmax = 3.5) and Chashniki (Mmax = 3.5) potential seismic zones were differentiated less reliably.
Voitekhovsky Yu.L.
Statistical analysis applied to the problem of rock ordering in lithosphere. pp. 19--26
Abstract: Indicator functions are used to test spatial correlations between mineral grains of different species in a rock. The biggest range obtained from all the covariograms is regarded to be the radius of minimal mineral aggregates representing a rock texture. These aggregates are defined to be those mineral clusters which build a rock by their superposition on one another. In accordance with statistical theory, translation of such clusters in a rock space is possible with controlled variation. In this sense, the principle of rock ordering looks like intermediate between the strict order and absolute chaos. The developed theory has been applied to gabbronorite from the Fedorova-Pansky Tundra intrusive, the Kola Peninsula.
ГЕОЛОГИЯ
Azhgirevich L.F., Anoshko Ya.I., Rylova T.B., Khursevich G.K., Shimanovich S.L., Yakubovskaya T.V.
Depositional environments existed within the territory of Belarus during the Late Oligocene. pp. 27--35
Abstract: Results of the several years' studies carried out within the territory of Belarus are discussed mainly the data of lithogenetic and paleobotanical investigations of Late Oligocene deposits mostly widespread in the south of Belarus were used to reconstruct paleogeographical environments and to distinguish their stage evolution. Peculiarities in the deposition of sediments during the Late Oligocene are related to the general evolution of paleogeographical conditions within the East European Platform resulted from the global events of that period. Firstly, these were climatic events in turn the resulted from geodynamic processes and were dependent on the territory position in the general position of lithospheric plates. The Late Oligocene stage of lithogenesis is subdivided into smaller intervals (Stradub, Krupeisk) which are typical for some specific areas, though are of regional importance. Integrated paleobotanical and lithologic-mineralogical investigations permitted to describe in details the Late Oligocene stage of lithogenesis and revealed more reliably both regional and local regularities in sedimentation. Paleogeographical peculiarities of the Late Oligocene lithogenesis distinguished within the territory of Belarus can be used to assess perspectives for useful minerals prospecting within this territory.
Poznyakevich Z.L., Slobodyanyuk I.A.
Lithologic and stratigraphic characteristics and correlation of Devonian supra-salt deposits of the Pripyat Depression. pp. 36--51
Abstract: Complex paleontological, lithological and geophysical logging data (from 250 wells) were used as a basis to reveal facies-lithological features of suprasalt deposits of the Pripyat Depression and to carry out stratigraphic subdivision and correlation. Deposits of the Luban, Starobin, Stviga and Borovoye layers of the Upper Devonian Streshin-Polessie Horizon, that were earlier observed only in characteristic sections of the western part, have been distinguished, studied and traced from one borehole to another one all over the depression territory. Data presented are indicative of erroneous identification of the gypsum-bearing subformation (Luban and lower Starobin layers) revealed in the western section of the depression with the certain part of the upper salt-bearing formation of the Shatilky Depression, as it was accepted at the Interdepartmental Regional Stratigraphic Conference for the elaboration of unified stratigraphic schemes of Belarus (Resolutions..., 1983). Schematic maps showing lithologic composition of the Luban, Starobin, Stviga and Borovoye layers of the Pripyat Depression have been compiled. The lithologic and facies characteristic of different section types for each of these subdivitions is presented.
Markovsky V.M.
Lithologic peculiarities of Middle Devonian deposits within the southern part of the Lvov Paleozoic Trough. pp. 51--58
Abstract: In the middle part of the Gold Lime (Zolotaya Lipa) river the left tributary of Dniester entirely a fragment of carbonate sequence of Middle Devonian deposits (Givetian) is exposed within quarry. The fragment is 35 m thick and located in the southern border of the deposits within the Volyn-Podoliya Segment of the East European Platform. The fragment differs from other sediments that are of the same age and occur in the central and northern parts of the Lvov Trough. It is a reason of scientific interest demonstrated to this fragment. A bioherm multicycle complex is presented in the outcrop. Beds of biostromal frame constructions and stromatolith units of equal thickness and separated by thin clay layers are presented in this outcrop. Detailed litholigie-petrographycal investigations of the sequence show that the original calcite material of all the types of organic calc was replaced by metasomatic dolomite. It caused a poor safety of skeleton remains and made difficult their identification. It is possible that bioherms are composed of algae and corals. These units are absent within the greater part of the Lvov Depression in deposits of the same age. A terrigenous-chemogenic complex of a brackish lagoon is found there. The dequence studied is proposed a stratotype of a new unit of the isolated structural-facies zone of the Lvov Depression.
Aksamentova N.V.
Formations and paleogeodynamics of the Early Proterozoic Osnitsk-Mikashevichy volcanic-plutonic belt. pp. 59--72
Abstract: The Osnitsk-Mikashevichy volcanoplutonic belt runs northeastwards for a distance of 650 km from the northwestern Ukraine to eastern Belarus. The belt occupies a discordant position relative to the folded structures of the basement composed of polymetamorphic gneissic complexes and in contrast to them is formed by various plutonic and volcanic rocks without evidences of strong regional metamorphism. Magmatic rocks of the Osnitsk-Mikashevichy belt are subdivided into nine formations differing in composition and origin: metagabbro-diabasic, diorite-granodiorite-granitic, latite-rhyolitic, subalkaline quartz-syenite-granitic, doleritic, rhyolite-alaskitic, subalkaline gabbro-doleritic, trachyandesitic and subalkaline gabbro-syenitic ones. They were formed during the second half of the Early Proterozoic and beginning of the Riphean 2100--1500 mln years ago. Almost all rocks show rather high alkalinity and ferruginous content increasing from older to younger formations. Subalkaline and alkaline rocks are enriched in rare lithophile elements. In diversity of magmatic rocks and their petrogeochemical peculiarites the Osnitsk-Mikashevichy belt is comparable to the Late Paleozoic Dzhungaro-Balkhash and the Mesozoic Mongolia-Okhotsk volcanic-plutonic belts which magmatic areas are extending far into the continents along deep fault zones. By analogy with these belts the Osnitsk-Mikashevichy one can be considered as a long-living intracontinental magmatic active zone initiated over a thick continental crust and developed under complicated paleogeodynamic conditions characterized by reapeatedly changed compression and tension of the Earth's crust. The similarity of the Osnitsk-Mikashevichy belt to the intracontinental active belts shows its predominant rare metal mineralization.
Konischev V.S.
Peculiarities of the structure and oil- and gas-bearing capabilities of the Pripyat and Dnieper-Donets basins. pp. 72--83
Abstract: Oil pools were discovered in the Pripyat Basin within the subsalt, intersalt and uppersalt deposits. There are no any oil pools in rocks of the basement and in suprasalt deposits. The oil and gas pools were found in rocks of the basement and suprasalt deposits in the Dnieper-Donets Basin. There are no any oil and gas pools in the subsalt and intersalt deposits. There is an asymmetry of oil contents in the Pripyat Basin: all commercial oil pools were found in the northeastern part of the Pripyat Depression in the Northern Zone of Steps. Only small uncommercial pools of heavy oil were found in the central and southern parts of the basin within the Central Graben. Oil and gas pools were discovered in the southern, central and northern parts of the Dnieper-Donets Basin and also in the Northern Shoulder of the basin. Such differences in the oil and gas contents of these basins are due to peculiarities of their structure, development, oil and gas generation, migration, and also formation and conservation of oil and gas pools. The principal difference of these basins consists in the smaller depth and thickness of the sedimentary cover within the Pripyat Basin. The basement rocks of the Northern Shoulder of the Dnieper-Donets Basin are covered with the Upper Visean and younger sequences that were deposited during the postrift stage of the basin development. The thickness of the sedimentary cover is 3000 m and more. Clays in the lower part of this sequence is a good seal for the basement rocks. The sedimentary cover thickness in the Northern Shoulder of the Pripyat Basin is less than 3000 m and usually does not exceed 1500 m. The basement rocks are covered with Riphean sandstones and have no any seal. That is why there are no good conditions for the formation and conservation of oil and gas pools in the basement rocks of the Northern Shoulder of the Pripyat Basin. The suprasalt deposits of the Pripyat Basin did not produce oil because of their small depth of occurrence. There are no good conditions for vertical migration of hydrocarbons into the suprasalt deposits from underlying strata, as the Upper Famenian salt formation occupies the whole territory of the Pripyat Basin and is a good seal. The suprasalt Devonian and Carboniferous deposits of the Dnieper-Donets Basin occur deeper and produce oil and gas. The lower Permian clay-salt formation is a good seal for these deposits. The subsalt and intersalt deposits of the Pripyat Basin produced hydrocarbons in the northeastern part of the Depression, because high paleotemperatures were observed only there. Subsalt strata of the Dnieper-Donets Basin are highly fractured with faults and have no good regional seal. That is why they do not show good conditions for the formation and conservation of large oil and gas pools.
Tolstosheyev V.I.
Structure of the surface of Carboniferous deposits in the western part of East-European Platform. pp. 84--90
Abstract: Сarboniferous deposits cover in the East European Platform west much smaller area as compared to that occupied by Devonian formations. They were preserved from washout in the west edge of the Moscow Syneclise, within the Pripyat, Dnieper and Lvov-Lyublin Troughs, where they are represented by Tournaisian, Visean and Serpukhovian deposits of the lower series, by the Bashkirian and Moscow deposits of the middle series, and by Kasimovian deposits of the upper series of the Carboniferous. The structure of the Carboniferous surface in the Pripyat and Dnieper Troughs was affected by salt tectonics, and in the Lvov-Lyublin Trough Carboniferous deposits were dislocated by a set of longitudinal faults. The structural and geological map shows Carboniferous deposits together with the more ancient formations overlain by Permian and Anthropogene rocks. This is indicative of paleogeology in part of the ancient platform west edge in the Carboniferous period.
Davydik K.I.
Peculiarities of the surface of marine Paleogene deposits in Belarus. pp. 90--101
Abstract: Morphologic and structural peculiarities of the surface of marine Paleogene deposits were investigated. The limits of the maximum transgression of the Paleogene sea in eastern Belarus were defined more exactly. A regional subdivision of the area under consideration according to its morphologic and structural features, as well as to the peculiarities of the main relief forming processes was suggested. Eight regions (the Grodno, Brest, Ratno, Pinsk, Minsk, Mozyr, Gomel, and Bragin ones) were recognized. The boundaries of the regions coincide largely with tectonic structures of the basement. The marine Paleogene deposits surface occurs at three hypsometric levels: high -- 110-130 m (the Ratno, Gomel regions and the southern part of the Pinsk region), middle -- 80--100 m (the Mozyr, Bragin, Brest regions and the northern part of the Pinsk region) and low -- less than 70 m (the Grodno region). Maximum changes of the initial surface are characteristic of the middle and low hypsometric levels (in the Grodno region the variation of its altitudes is more than 200 m). The influence of neotectonic and glaciodynamic processes on the postdepositional changes of the Paleogene surface was revealed. Minimum depths of this surface occurrence (as low as 25 m) were found in the Gomel, Bragin and Pinsk regions. Areas promising for mineral resources and associated with marine sediments of the Paleogene may be revealed within the mentioned territories.
Dobkevicius M.
Closer definition of laboratory filtration coefficients according to the data of field tests. pp. 101--109
Abstract: The certain correlation between the parameters obtained in the course of field and laboratory tests was noted and revealed during numerous infusions to the excavations for the determination of filtration coefficients of the rocks of the aeration zone together with determination of their physical properties and laboratory filtration coefficients according to the transient water filtration scheme in G. Kamenski tube. This allowed us to establish the correction for the systematic error between the field and laboratory parameters, which introducing permits the use of the laboratory filtration coefficients as real ones. Moreover, it was established by the field tests that the size of standard rings of N. Nesterov infiltrometer (i.e. a ratio of their outer and inner diameters can not) ensure the vertical flow from the inside tube in low permeable rocks, and hence the values of filtration coefficients increase. Special infusions to the excavations were made with different diameters of infiltrometer rings and the optimum diameters were found that provide the real filtration parameters.
Zinovenko G.V., Monkevich K.N. †, Nagorny M.A.
Strategy of mineral prospecting in Mesozoic deposits of Belarus. pp. 109--117
Abstract: New regional approaches suggested for prospecting such minerals as copper -- in Triassic formations, coal -- in Jurassic, phosphorites and glauconite-bearing strata -- in Cretaceous deposits were based on the results of analysis of a great body of geological information on Mesozoic deposits found within the territory of Belarus which were correlated with global geological processes that took place in the European continent during the Mesozoic. It was assumed that the copper mineralization is of local (deltaic) character and may be confined to the western coastal zone of the Triassic paleobasin within the Pripyat Trough. A zone promising for Jurassic coals was distinguished within the Pripyat Trough between the modern limits of Mid-Jurassic deposits and approximately a zero isohypse of their base. Horizons promising for phosphorites are related to Cenomanian deposits found within a zone adjacent to the northern boundary of their base. Horizons promising for phosphorites are related to Cenomanian deposits found within a zone adjacent to the northern boundary of their spreading except for the region of the Polessian Saddle where Cenomanian deposits are represented by alluvial cone facies. The location of quartz-glauconitic sands and Albian sandstones shown which are of interest as glauconite-bearing strata was shown.
ГЕОФИЗИКА
Boykov A.M.
Climatic "memory" of geothermal field. pp. 118--124
Abstract: A method of modelling of a climatic "memory" stored in the geothermal field under conditions of the groundwater filtration is described. A reliability of various methods used in reconstructing fluctuations of the Caspian Sea level caused by the transgression-regression cyclic recurrence was estimated from the results of geothermal field modelling. The radiocarbon method is considered as the most reliable and is chosen as the basis for modelling in the context of paleogeothermal studies of the problem. Both the character and depth of propagation of the surface temperature paleojumps into upper horizons were estimated under conditions of upward and downward filtration of groundwater. The estimates were made for the ground paleotemperature fluctuations in the northern part of the Caspian Sea region.
ГЕОХИМИЯ
Arkhipova A.A., Naidenkov I.V.
Regional clarkes of petrogenic and trace elements in crystalline basement rocks of Belarus and their average chemical composition. pp. 125--134
Abstract: The paper cites the average background values of petrogenic and trace elements calculated for the main rock types of the crystalline basement of Belarus, as well as the regional clarkes calculated for the crust of the region as a whole (without sedimentary cover). Results of 2,048 complete silicate and 3,248 semiquantitative spectrum analyses carried out for 40 elements have been used in calculations. The average chemical composition of the Earth's crust in Belarus calculated with A.P.Vinogradov's procedure was found to be corresponding to quartz diorite approximating to granodiorite (63.67% of silica). The data obtained show a good correlation with previously calculated clarkes (Vinogradov, 1962 еt al.) of chemical elements in the Earth's crust as a whole. However, these data are representative of some peculiarity of the chemical composition of the regional continental crust that is high in iron, scandium, tin, barium and partly phosphorus, lead, zirconium, yttrium, ytterbium and lanthanum, and low in alumina, chromium and nickel. It has been found that rocks of different origin, but similar in basicity contain similar amounts of most elements. Regional clarkes cited in the paper may be used in various geochemical and metallogenic studies as a groundwork for determining anomalous elements in rocks and minerals, as well as in interpreting geophysical data.
Olkhovik Ye.T., Bordon V.Ye.
Geochemical model of the system "Crystalline basement -- weathering crust -- sedimentary cover". pp. 135--143
Abstract: The paper presents the data on the distribution of minor elements in the "crystalline basement -- weathering crust -- sedimentary cover" system. The basement rocks are rich in silver and bismuth, and specific rock varieties from some boreholes -- in scandium, copper and chromium. A poor migration capacity of these elements resulted in their accumulation in the weathering crust, the more mobile copper only was removed from the denudation zone. Long breaks showing good infiltration properties contributed to the removal of many elements from the rock formation zone. Higher concentrations of boron, chromium, tin, cerium were noted in sedimentary rocks of this region. The reasons of the redistribution of elements are analyzed. A special attention was given to individual geochemical associations when studying the metallogenic orientation of the region.
Petukhova N.N., Kuznetsov V.A.
Geochemical specificity of buried soils in the Nieman river valey. pp. 144--152
Abstract: Geochemical peculiarities of Holocene soils showing different stratigraphic position have been investigated. Their chemical composition depends in many cases on lithogeochemical peculiarities of soil-forming alluvial sediments and considerably differ from the riverhead to the lower reaches of the Nieman river valley. That allowed the authors to distinguish and to characterize four pedogeochemical districts: Stolbtsy, Lubchany-Morin, Mosty and Grodno ones. The characteristics of Holocene soils have been obtained from the study of high floodplain exposures, where buried soil horizons are abundant. Palynological, paleocarpological, radiocarbon and archeological evidences obtained by L.N. Voznyachuk, M.A. Valchik, Ya.K. Yelovicheva, M.E. Zus provide a substantiation of their spatial and temporal differences. It is shown that the evolution of the chemical composition of the soil cover was of rhythmic and cyclic character depending on the changes of paleogeographical conditions (geological, climatic, biocoenosis ones and others). The Early, Middle and Late Holocene soil horizons have been distinguished and geochemically characterized. Their major geochemical indicators have been ascertained.
Kudelsky A.V., Starodubova A.P., Fedenya V.M., Burak V.M.
Ecology of territories of former military bases. pp. 153--166
Abstract: It has been established that the ecological situation in sites formerly occupied by military bases does not satisfy the nature management and living standards. The soil cover is generally contaminated by petroleum products, heavy metals, highly toxic chemicals and radionuclides; forest ecosystems are damaged as a result of firing practice, tactical exercises, forest felling, etc.; surface and subsurface water sources are polluted and partly or completely rendered unfit for use. The oil content of soil and ground varies over a wide range from a few fractions of milligrams to hundreds grams per 1 kg of soil, when the soil sample inflammation is noted (rocket bases in Postavy, Ruzhany, etc.). The subsurface horizons are polluted by oil products as deep as 5 and even 8-10 m (Postavy, Ruzhany, Krasnitsa-2, etc.). Arsenic, manganese, nickel, copper, zinc, molybdenum, cadmium and lead pollution of the soil cover is noted higher than their background values. The concentrations of these elements are particularly high in the soil cover within fuel and lubricant depots, motor-garages, starting grounds and residential complexes. Lead is the most dangerous environmental pollutant among heavy metals. Its content in soil is generally high (from a few to 50 and even 154 mg/kg). Lead migrates actively into natural water where its concentration ranges within 0.8 and 9.0 mg/l, which is 25 to 300 times the maximum-allowable concentration for drinking water (0.03 mg/l). The analysis of the data available shows that territories and natural complexes within the former military sites in Belarus (soil, natural water, etc.) are polluted by highly toxic substances of various origin to ecologically hazardous levels that prevent their economic utilization without expensive restoration works and ecological rehabilitation. Some methods of restoration works are discussed, as well as additional ecological research required for elaborating projects aimed at ecological recultivation of lands, subsurface area and subsurface aquifers and based on appropriate up-to-date technologies.
КРАТКИЕ СООБЩЕНИЯ
Kalinovski P.F., Kovalyukh N.N.
Age of the mammalia paleofauna from the Smorgon site. pp. 167--169
Pavlovskaya I.E., Gulis L.F.
Correlation of the crystalline relief of basement surface and neotectonic structures of Belarus. pp. 169--171
Akudovich S.A., Tratsevskaya I.R.
The procedure and results of analysis of the trace element composition of brines of the Pripyat Trough. pp. 172--174
Sardarov S.S., Sheikhov Yu.G.
Geothermal reconstructions resulted from the analysis of dischargeless water reservoirs. pp. 175--177
ХРОНИКА. pp. 178--192
ПАМЯТИ УЧЕНОГО. pp. 193--195
НОВЫЕ КНИГИ. pp. 196--199
/ Издания академии / Научные журналы / К началу страницы
Designed and maintained by Dr. Nikolai N. Kostyukovich. Last updated: January 6, 1999
Created with assistance of Dr. Ignatii I. Korsak
Copyright © 1999 The National Academy of Sciences of Belarus
Copyright © 1997 The Institute of Geological Sciences of the NAS of Belarus
