Èçäàòåëè: Èíñòèòóò ãåîëîãè÷åñêèõ íàóê Íàöèîíàëüíîé àêàäåìèè íàóê Áåëàðóñè è Áåëîðóññêîå ãåîëîãè÷åñêîå îáùåñòâî, Ìèíñê, Ðåñïóáëèêà Áåëàðóñü
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ËÈÒÎÑÔÅÐÀ Èçäàòåëè: Èíñòèòóò ãåîëîãè÷åñêèõ íàóê Íàöèîíàëüíîé àêàäåìèè íàóê Áåëàðóñè è Áåëîðóññêîå ãåîëîãè÷åñêîå îáùåñòâî, Ìèíñê, Ðåñïóáëèêà Áåëàðóñü |
Abstract: G.I.Goretsky devoted a lot of his papers to the Quaternary geology of the Ukraine, among them "Alluvial chronicle of the Great Original Dnieper" (Goretsky, 1970) should be mentioned as a fundamental monographic essay. Using numerous evidences, firstly, drilling data G.I.Goretsky contibuted to the development of two leads in the Ukrainian geological science: study of alluvial deposits of the original Dnieper and investigation of glacial formations. He was first to distinguish the Vened glacioalluvial and Lower and Upper Krivichi alluvial suites and described for the first time the Lower Quaternary Nikopol terrace. G.I.Goretsky used not only geomorphological and paleontological criteria, but also the paleopotamological method to determine the age of terraces. Within the middle reaches of the Dnieper G.I.Goretsky distinguished a periglacial terrace up to 120-140 m in height and associated its origin with a high sea level during Post-Dnieper time. Similar terraces were previously distinguished in the valleys of the original Volga and original Don. G.I.Goretsky made an important contribution in discovering, studying and elucidating the origin of overdeepened valleys of glacial scouring and washout situated on the left bank of the Dnieper. He discovered a valley as deep as 150 m within the area stretching from Pereyaslav to Cherkassy. It was infilled with the Dnieper age till and glacial alluvium, which G.I.Goretsky differentiated as the Shevchenko suite of the Dnieper glaciation. G.I.Goretsky attributed the origin of the Kanev and Moshnogorie glacial tectonics to the action of the Dnieper glacier. He was first to distinguish the Sokirin glacial valley and the glacioalluvial Trubezh suite. He pioneered the study of the original Zamglai valley and alluvial deposits of the Vened, Lower and Upper Krivichi suites buried there.
Gursky B.N.†
Problems of genesis of Quaternary (Anthropogene) deposits discussed in the papers by G.I. Goretsky. pp. 12--18
Abstract: Papers concerned with problems of genetic classification of Quaternary deposits and aimed at revealing their formation conditions have a significant place in the scientific heritage of G.I.Goretsky. There are three series of papers that discuss: 1) the theory of a periglacial formation; 2) genetic types of alluvial deposits; 3) problems of classification of moraines. G.I.Goretsky interpreted a periglacial formation as a transition between the interglacial and loessial ones. He distinguished 13 genetic types and varieties of deposits that compose the periglacial formation. G.I.Goretsky had consistently studied alluvial deposits. He had developed a genetic classification of alluvial deposits and suggested criteria for the alluvial facies determination. G.I.Goretsky considered the grain size increasing down the section to be the most important distinctive feature of alluvial sands. Alluvium, in his opinion, is a regular combination of floodplain, channel, oxbow, outwash and other facies. G.I.Goretsky believed that one of the most important tasks in studying morainic deposits is searching for their evidences that permit an investigator to distinguish between moraine and pseudomoraine. G.I.Goretsky differentiated surface (formed on the surface) and waterlain (deposited in water) moraines. Surface moraines were divided into those deposited by moving ice terminal moraines (slowed-down ice movement) and morainic kames. Stream till (a variety of waterlain moraine) was considered to be most promising for deposits of building materials.
Yelovicheva Y.K., Sanko A.F.
Palynostratigraphy of the Poozerie (Weichselian) glaciation in Belarus. pp. 18--28
Abstract: Sediments of the late (Poozerie, Weichselian) glaciation in the territory of Belarus have been described by the palynological method. The study of deposits of various geneses has been accompanied by revealing the modes of their occurrence and by their dating using radiocarbon and thermoluminescence methods. All these resulted in the Poozerie sediments subdivision into three subhorizons: Kulakovo, Dvina and Naroch ones. The Kulakovo (early Poozerie) subhorizon corresponds to the 5a-d isotopic stage and includes the West-Dvina megastade with the short Cherny Bereg interstade and three well-defined interstades (Cherikov, Surazh, Polotsk). The Dvina (middle Poozerie) subhorizon (pleniglacial, 4th and 3rd isotopic stages) consists of the Mezhin and Orsha megastades. A megainterstade between them includes three middle Poozerie interstades: Turov, Shapurovo and Borisov ones. The Naroch (late Poozerie) subhorizon (2nd isotopic stage) correlates with the Poozerie Late Glacial. The correlation of the interstades may be represented as follows: the Cherikov interstade corresponds to the Amersfoort interval, Surazh - to Brorup, Polotsk - to Odderrade, Turov - to Moershoofd, Shapurovo - to Hengelo, Borisov - to Denekamp.
Veklich M.F.
G.I. Goretsky and paleopotamology. pp. 29--36
Abstract: Czechoslovak researcher Fr.Rikovsky was first to suggest the term "paleopotamology" in 1929. Paleopotamology was developed as an independent geological science by academician G.I.Goretsky in his numerous papers and monographs. G.I.Goretsky defined the subject and tasks of paleopotamology, worked out a classification of paleorivers, methods, techniques and major lines of investigations, studied the stratigraphy, types and facies of alluvial deposits of the Anthropogene, discovered the valleys of glacial scouring (exaration) and wash-out and described their distinctions from buried river valleys. G.I.Goretsky proved the practical importance of the paleopotamological method. Alluvial deposits are objects of paleopotamological studies. G.I.Goretsky gave the name "paleorivers" to streams that had existed from the Precambrian to the Anthropogene, Mesozoic and Cenozoic rivers formed a separate group of proper paleorivers, and Anthropogenic rivers were identified as "original rivers". G.I.Goretsky considered paleogeography, paleogeomorphology and geology to be the major leads in paleopotamological research, however he stressed an importance of a complex application of granulometric, physical-technical, geochemical, mineralogical, petrographic, palynological, paleocarpological, diatomic, conchological, microfaunistic and other methods of investigations. G.I.Goretsky was first to recognize the Solikamsk, Vened, Lower and Upper Krivichi suites in the composition of the Anthropogene. He subdivided fossil alluvial deposits into the exposed (those manifested in the relief) and hidden (buried in tectonic subsidences) ones, and elaborated in detail the theory of alluvial facies. The works of academician G.I.Goretsky confirmed that the paleopotamological method is of practical importance, in particular, in correlating continental and marine deposits, in compiling stratigraphic schemes, in studying neotectonics and buried relief, in searching for groundwater.
Kalinovsky P.F.
The beaver remaines from the Smorgon site on the Vilia river. pp. 36--41
Abstract: Bones of the only representative of rodens (namely of Castor fiber) have been found among 26 mammalia species of the buried fauna remains at the well-known Smorgon site. The fossils date back to the Holocene, that was confirmed by the radiocarbon dating of the tubular bones (7.500𫏌 yrs BP; Ku -- 4.527). The age has been determined by N.N. Kovaliukh (Institute of Geochemistry and Physics of Minerals of the Ukrainian Academy of Sciences). 34 remaines of beavers (2 cranium fragments, 10 lower mandibles, 12 femoral bones, 4 humeral bones and 6 shinbones) have been collected. They belong to at least 8 individuals. The fossils are generally well preserved, their fragmentation being due to mechanical damage during extraction from alluvium together with building materials. The bone matter is light brown and the enamel is light grey, that may be evidences for their relatively young geological age. The study of the beaver's bones from the Smorgon site has shown that the remains belonged to old, adult and young individuals. Measurement of the fossil tooth apparatus and postcranial skeletons of beavers from the Smorgon site and their comparison with the analogous bones of this rodent from Holocene deposits of the Baltic region have shown their identity in structure and size. Bones of recent beavers from Belarus (Niemen and West Dvina basins), as well as from the other regions of the Russian Plain are in some instances smaller than those of fossils animals, or show nearly perfect proportions. First of all, this is concerned with teeth (especially of the upper mandible) and humeral bones. The mentioned bones of fossil beavers are larger in size than those of the recent ones.
Vinokurov V., Komarovsky M.
The most valuable geological objects of Belarus. pp. 42--48
Abstract: Quaternary deposits are the most widespread formations in the territory of Belarus. They had been formed during Pleistocene glaciations and cover the whole territory of the country with up to 320 m thick overburden. The standard Pleistocene and Holocene outcrops, large boulders and expressive landformes are the reference ones and form an essential part of the most scenic landscapes of Belarus. Ten most interesting nature zakazniks (protected areas with some unique nature elements without administrative authorities/Category 4 in the IUCN classification/), and monuments situated in various geological regions of Belarus are suggested to be included in the List of the most important geosites of the Middle European Lowlands. These are the territory of the landscape zakazniks which include end-morainic ridges and hills of standard morphology with a group of lakes found in the glacial valley, which is a type marginal runoff valley, and an expressive end-morainic ridge; outcrops of lake, lake-boggy and peat deposits of the Holstein; stratotype sections exposing interglacial deposits; one of three locations of Devonian dolomite known in the world; one block of the conglomerate and three largest erratic glacial boulders.
Kalitski T.
Evolution of some river valleys of Belarus in the Late Glacial Age and Holocene. pp. 49--55
Abstract: The Dnieper and Zapadnaya Berezina valleys have been studied. Proglacial waters had flowed to the south along these valleys during the Vistulian. River captures are characteristic of them in the lower reaches of the rivers. The only young Vistulian terraces occur there since the older ones had degraded. Nowadays all the rivers are underfit. The author differentiates a new "Dnieper" type of these rivers. Their underfitness manifests itself by occurrence of "dead valleys". Within the Zapadnaya Berezina valley braided rivers are gradually replaced by large Late-Glacial paleomeanders and then by small Holocene meanders. This type of changes is common in Central Europe, but was firstly described in Belarus. Differentiated tectonic movements (Dnieper, Berezina) and hydrological changes (West Berezina) had an important influence on the postglacial evolution of these valleys. This is illustrated by the type of evolution: vertical accretion of the Dnieper floodplains, changes of the Berezina channel and formation of alluvial strata of different age within a floodplain, peat deposition in the floor of the Zapadnaya Berezina valley (Fig. 1). Phases of the increased river activity connected with the climate changes (ca 5.000, 3.100, 1.000 BP, Little Ice Age) are shown in the changes of the channel, sedimentation type (Berezina), as well as in fossilization of soils (Dnieper). Human activity caused fossilization of soils and changes of the granulometric composition of overbank deposits (Dnieper), accumulation of alluvial fans within the valley floor (Zapadnaya Berezina) and formation of the floodplain lowermost level (Berezina).
Astapova S.D.
Erratic nature of interglacial beds in the section at Obukhovo. pp. 56--60
Abstract: The outcrop at Obukhovo has been known since 1933 when it was described for the first time by F.V. Lungersgauzen. It is located on the left bank of the Saryanka river (right tributary of the Zapadnaya Dvina) opposite the settlement of Obukhovo (Vitebsk region). Ancient lacustrine deposits are of special interest in the sequence, as their age determinations vary from the youngest Muravian to Belovezhian ones. The mode of these beds occurrence is a debated topic, therefore, the importance of this sequence as a stratotype is still open to question. The material composition of the Obukhovo sequence at, in particular, that of its moraines has been studied in detail and analyzed in the context of the moraines belonging to some specific glaciation. The material composition of moraines is dependent on the peculiar features of rocks of distributive provinces, where the ice flow or glacial lobe beds are located. The micropetrographic indexes determined by the author in the moraine composition have been used to establish the fact that the moraine which underlies interglacial deposits and that overlying them had been formed by the same ice stream and belong to the same glaciation. Interglacial deposits occurred within the moraine as an erratic mass thus indicating an imbricate character of glacial movement along englacial fractures, which is typical of territories showing buried positive structures or fault zones. Some characteristics derived as a result of micropetrographic correlation show that the moraine which involves interglacial deposits belongs to the Dnieper glaciation of the Pleistocene. Some evidences of the Poozerje glaciation are also revealed in this sequence from the composition of the uppermost sandy-gravel horizon formed as a result of the Poozerje moraine washout.
Abstract: Genetic classification is an hierarchic system of internal differentiation of the geological environment by the classes and taxons of various levels. The order of functional subordination of geological bodies, processes, events differing in specific features that reflect the general processes, or in particular features of formation and conditions of development plays the leading part in classification. Principal problems inherent to genetic classification schemes are as follows: 1) imperfect knowledge of geological processes and causes of their origin; 2) similarity of many geological bodies that are related to different genetic accumulations; 3) continuous transitions between geological bodies; 4) impossibility of direct observation of geological and other processes; 5) poor knowledge of the sediments deposited due to joint action of several geological agents; 6) different understanding and use of the terms "facies", "genetic type", "formation", etc.; 7) absence of reliable indicators which can be used to identify facies, genetic types and formations. Genetic features are generally relative, they should be distinguished on the basis of identified heterogeneities of an object and its properties, as well as on clear and conveniently understandable definitions, targeted tasks and methods of checking study results. Logical differentiation of the definitions of the conditions and environment of sedimentation has permitted the more accurate definition of facies, genetic type, formation, etc. Facies is a local genetically homogeneous geological body with its specific and inherent typical features that describe the formation, structure, mode of occurrence and composition: shape, dimensions, border contacts, frequent manifestation in the relief, textural, mineralogical-petrographic, physical-chemical, physical-mechanical, paleontological and other peculiarities. They all reflect a specific and uniform depositional environment and set off this body from other geological formations. Genetic type is a complex of homogeneous, genetically related, uniform or similar geological bodies /facies/ having sufficiently extensive occurrence and showing essential indications of genetically common principal features of structure, mode of occurrence and composition that evidently reflect a dominant geological process of sedimentation. Formation is a paragenetic complex of heterogeneous types and facies that occur together in a single extensive spatial and temporal community of glacial, periglacial and other specific conditions of sedimentation while its structure shows similarity of paleogeographic, geological-dynamic and tectonic impacts. The suggested more precise definitions, as well as conceptual principles of the framework of genetic classification will be a useful tool in solving the problem of genetic classification of the Quaternary deposits.
Sveshnikov K.I.
Areas of plutonic associations as a source of information about deep magmatic processes. pp. 70--75
Abstract: Plutonic associations (groups of plutonic bodies showing the similar composition and the same geological position) often form belts or isometric areas their length ranging from tens to thousands kilometers. Besides, the composition of such associations can be characterized by many features (such as a distance between massives, their symmetric or asymmetric spreading, successive changes of their dimensions, petrographic and petrochemical peculiarities, radiological ages along and across the areas), that reflect regional features of deep magmatic processes. The possibility of obtaining new information about magmatic processes is demonstrated with three examples of plutonic associations: 1) Early-Proterozoic granite-granosyenitic association, which forms the belt extending from the Ukraine to Belarus, 2) Late Archean-Early Proterozoic diorite-granitic belt in Eastern Siberia, and 3) Paleozoic-Mesozoic system of associations, which covers a vast area in Eastern Asia and consists of many plutonic belts of different composition. The following main conclusions have been drawn. The periodic recurrence of plutonic bodies with the similar composition within large areas must be connected with the generation of a series of independent magma chambers that occurred at the same depths. This phenomenon can be explained by spreading of subhorizontal stress waves in the lithosphere. An age shift of magmatic processes which is observed over large territories is their integral property, which depends on the velocity of such waves. The latter can be estimated by a difference between radiological ages of massives with the same composition. In Eastern Asia it was found equal to 1 cm/year.
Abstract: Early-Middle Devonian deposits in eastern Belarus overlie Proterozoic rocks with a large stratigraphic break. They are represented by terrigenous, sulphate, more rarely carbonate sediments. The palynological study is the major method of their subdivision and correlation. These deposits have are been divided into miospore zones. The Diaphanospora inassueta zone corresponds to the Vitebsk horizon. It is characterized by Diaphano-spora impolita, D. impolita var. modestus, Lanatisporites hispidus, Gneudnaspora divellomedium, Calyptosporites tener, Calyptosporites tener var. consinnus, Archaeozonotriletes ignoratus, Stenozonotriletes incessus, Retusotriletes actinomorphus, Punctatisporites tortuosus. Repsesentatives of the Dibolisporites and Apiculiretusispora genera are prevalent in spectra, and all their species pass into the overlying deposits. The first arrival of Calyptosporites velatus was noted in the upper part of this zone. The association of miospores is compared with that from the Grandispora douglastovnense-Ancyrospora euryptorota zone in the upper part of the Emsian and lowermost part of the Eifelian (Richardson, McGregor, 1986). The Periplecotriletes tortus - Elenisporis biformis zone corresponds to the Adrov and Osveya horizons which are suggested to be united in a single Zapadnaya Dvina horizon. Periplecotriletes tortus, Retusotriletes fragosus and species Calyptosporites velatus, Acinosporites acanthomammilatus, Rhabdosporites mirus are typical of this zone and appear at its lower boundary. In the spore composition, this part of the section may be compared with the Calyptosporites velatus-Rhabdosporites langii zone distinguished in the lower part of the Eifelian stage of West Europe and Canada (Richardson, McGregor, 1986; Arkhangelskaya, McGregor, Richardson, 1990). The Grandispora naumovii zone is distinguished within the Gorodok horizon. Its lower boundary is traced by the appearance of Hystricosporites setigerus, Ancyrospora grandispinosa, Corrystisporites collaris, Perotrilites bifurcatus, Grandispora naumovii and by an increasing number of Rhabdosporites langii. The spores of the Dibolisporites and Apiculiretusispora genera gradually decline in number in deposits of this zone. The spore composition may be correlated with those from the Eifelian stage of West Europe and Canada (McGregor, 1979; Richardson, 1965; Richardson, McGregor, 1986). It is suggested to restrict the Rhabdosporites langii zone volume to the Kastjukovitchy horizon. Its lower limit is evidenced by the arrival of Chelinospora ligurata, Lophozonotriletes scurrus, Verrucosisporites premnus, Convolutispora tegula, Cirratriradites monogrammos, Retispora archaeolepidophyta, Grandispora inculta. The greatest amount of Rhabdosporites langii is confined to this layer. Representatives of the Dibolisporites and Apicvuliretusispora genera become extinct within this zone. The zonal spore complex is correlated with spore associations from the Grandispora naumovii-Densosporites devonicus zone, which is typical for the upper Eifelian-lower Givetian (Richardson, McGregor, 1986). The absence of miospores ex gr. Geminospora lemurata in the Kostjukovichi horizon relates the deposits to the Eifelian. The overlying deposits of the Polotsk horizon are related to the Givetian stage (Geminospora extensa zone) amd may be compared with the Givetian deposits of Poland (Turnau, 1995) and upper Givetian deposits of Blacourt in France (Loboziak, Streel, 1980).
Tolkachikova A.A.
Aluminous rocks of the Kulazhin series in the basement of the Pripyat Trough. pp. 86--90
Abstract: The study of the crystalline basement rocks of the Pripyat Trough is of both scientific and practical interest in the context of possible occurrence of oil and gas accumulations in Precambrian formations. Rocks of the basement drilled by largely spaced holes are worth of special study. One of such holes (Gorodok-4) drilled in the zone of the North-Pripyat marginal fault has exposed strata of highly metamorphic rocks of the Archaean gneissec complex: aluminous gneisses with garnet granite bodies and interlayers of peraluminous (as much as 27% of Al2O3) rocks -- cordierite-garnet-sillimanite-biotite-spinel-bearing gneisses met for the first time in the crystalline basement of the Pripyat Trough. The study of mineralogic and petrochemical features of rocks in a borehole log has allowed the estimation of thermodynamic conditions of regional metamorphism and definition of aluminous and peraluminous gneisses as primary sedimentary rocks metamorphosed under the granulite fasiec conditions and subsequently transformed by the processes of regressive metamorphism and potassic metasomatism.
Matveyev A.V., Nechiporenko L.A.
The Earth's crust structural features shown in the relief of Belarus. pp. 91--94
Abstract: Some peculiar relief features showing deep mantle faults and crustal blocks have been investigated. It has been shown that some structures had an impact upon the dynamics of ice sheets, location and morphometric characteristics of bogged lake-glacial, lake-alluvial lowlands, some areas of fluvioglacial plains, marginal glacial landforms and the general orographic aspect of the region. However, the peculiar structure of the Earth's crust is most pronounced in the hydrological network (the valleys of many rivers - Pripyat, Zapadnaya Dvina, Disna, Drut, etc. and lake basins are confined to deep fault zones), in changes of the river valleys outlines, river streams, meandering pattern when disjunction zones are replaced by blocks and vice versa. It has been also found that some crustal structures had an appreciable Åffect upon the trend and density of cosmolineaments. The whole complex of features discussed above allowed a conclusion about the activation of some disjunction zones (or their specific area) and crustal blocks at the recent and modern stages. This concerns, firstly, with zones of sublatitudinal faults in northern (axial line runs across Vidsy settlement - Polotsk town - Usvyaty settlement in the territory of Russia) and southern (axial line runs across Kamenets town - Logishin settlement - Ozarichy settlement - Uvarovichy settlement) Belarus, with a submeridional zone in northern Belarus (axis runs across Rossony settlement - Obol settlement - Chashniki town - Bobr settlement), as well as with the Lepel, Minsk blocks and southern part of the Vilnius block.
Konischev V.S.
Peculiarities of the North-Pripyat and Glusk-Berezina faults evolution. pp. 95--104
Abstract: Using a detailed correlation of logs of boreholes drilled in uplifted and downthrown walls of the studied faults and the analysis of thickness and facies of the prerift, synrift and postrift deposits as the basis the author has traced the history of their development and proved that they had formed at the rift and postrift stages. The rift stage involved of the Rechitsa phase of tectonic and magmatic activation, Voronezh-Yevlanovo phase of weak rifting, Yevlanovo-Liven phase of active rifting, Domanovichy-Yelets phase of depressed rifting, Petrikov-Streshin phase of intensive rifting and Polessie-Early Visean final phase of attenuated rifting. The velocity of vertical displacement along the faults ranged within 33 m/mln years in the Voronezh-Yevlanovo phase to 273 m/mln years in the Yevlanovo-Liven phase of active rifting, decreased to 45 m|mln years in the Domanovichy-Yelets phase and increased to 670-830 m/mln years in the Petrikov-Streshin phase of intensive rifting and then decreased again to 40-116 m/mln years in the Polessie-Early Visean final phase. 50-80% of amplitudes of faults were formed during the Petrikov-Streshin phase of intensive rifting. At the stage of superimposed syneclise the velocity of vertical displacement along the faults decreased from several metres in the Paleozoic to 0.09-1.44 m/mln years in Mesozoic and Cenozoic and were thousand times less than during the principal Petrikov-Streshin phase of the rift stage. There were an inversion of movement along the eastern part of the North-Pripyat fault in the Mesozoic and Cenozoic with an amplitude as high as 174 m and a velocity of displacement ranging from 0.10 to 0.82 m/mln years. This was due to the tectonic regime changing from stretching to squeezing. The total size of stretching in the zone of the North-Pripyat and the Glusk-Berezina faults was 17.5-26.6%.
Zui V.I.
Climate change in Belarus derived from thermograms. pp. 105--112
Abstract: Terrestrial temperatures were measured during several years both in shallow and deep boreholes in Belarus mainly for heat flow studies. The thermograms, registered under steady-state conditions in holes within all main tectonic units of the country, have sometimes both concaved and convexed shapes. They have an imprint of the ground surface paleotemperature change. Temperature fluctuations at the ground surface propagate into the ground with attenuated amplitudes and the phase shift, dependent on the depth. A few temperature versus depth diagrams without noticeable influence of ground water circulation were selected for paleoclimatic reconstructions. First estimates show that the ground surface warming 0.5-1 °C took place during the last 200-300 years. The reliability of the climatic signal, derived from thermograms, is dependent on local conditions. For instance, the groundwater circulation, the agricultural effect, resulted from the cultivation of the land, but no detailed information is available both on the history of the agricultural use of the land around studied boreholes and the velocity of water filtration in the vicinity of selected sites.
Abstract: Some hypotheses for the association of pipe fields with certain tectonic conditions are analyzed in the paper. It was noted that the most part of the ancient East European Platform including the region under review corresponds to Clifford's rule about a correlation between diamond kimberlite occurrences in fields of ancient cratons cut by linear fault structures. Recent geophysical investigations and drilling data were used to describe tectonic conditions in the region of the Zhlobin and Uvarovichi field pipes. In was shown that pipe fields are associated with areas of a triple junction of graben-like structures. It was noted that a "hot point" shown as a heat flow anomaly is located at the junction of the Pripyat Trough, Dnieper-Donets Trough and Klintsov Graben. The analysis of geophysical fields has permitted the authors to suggest that the Chashniki fault extends further south. A possibility of discovering pipe fields in southeastern Belarus and neighbouring areas of Russia and Ukraine has been discussed.
Abstract: Titanium is related to typomorphic elements found in Belarusian landscapes. Amorphous forms of titanium compounds bonded to hydroxides and organic matter participate in the landscape migration of chemical elements, hypergenic formation of minerals, sedimentation and lithogenesis, in the formation of the water, soil and vegetative cover composition. The titanium proportion in hydroxides and the organic matter of sediments and soils varies between 0.05 and 0.81 and 0.05 and 6.4% of its bulk content. Results of experiments show that the sorption distribution coefficient for titanium hydroxide is 91.4-96.3 of Sr-90 and 14.2-15.3 of Cs-137, and the desorption degree is estimated as 9.8-13.1 and 85.5-95.1% correspondingly. Titanium-organic complexes are capable to abzorb up to 25% Sr-90 and 7-8% Cs-137 in 50 Bk-solution. The dependence of these processes on pH, crystallization degree of the hydroxide, concentration and correlation of radioisotopes are discussed. The role of titanium hydroxide as a factor of accumulation and dispersion of radionuclides is estimated.
Semenov V.Yu.
Estimation of the mantle geoelectrical structure in Belarus. pp. 128--130
Abstract: The analysis of the Pleshchenitsi (MNK) observatory data obtained within 1969--1989 has been carried out to estimate the response functions in the period from 7 to 110 days. The 1D inversions of these results together with the results for daily and deep magnetotelluric responses published previously allowed the estimation of the mantle conductivity structure in the depth range of 150 to 2000 km. The conductive zones have been detected in the depth ranges of 280 to 380 and 700 to 900 km. The asthenosphere of about 2 kS conductance can probably exist below a depth of 100 km.
ÕÐÎÍÈÊÀ. pp.131--145
ÏÀÌßÒÈ Ó×ÅÍÎÃÎ. pp.146--149
ÏÎÒÅÐÈ ÍÀÓÊÈ. pp.150--152
ÍÎÂÛÅ ÊÍÈÃÈ. pp.153--154