(Lithosphere)
Published by The Institute of Geological Sciences of the National Academy of Sciences of Belarus & The Belarusian Geological Society, Minsk, Republic of Belarus
|
LITASFERA (Lithosphere) Published by The Institute of Geological Sciences of the National Academy of Sciences of Belarus & The Belarusian Geological Society, Minsk, Republic of Belarus |
Abstract: The most important problems of studying the lithosphere in the fields of stratigraphy, lithology and palaeogeography, tectonics, the crystalline basement, Anthropogene history, geophysics, etc. are highlighted and defined. Mineral resources of the Republic are briefly outlined. It is emphasized that a new approach to the mineral wealth estimation and utilization is required in sovereign Belarus. To solve this efforts must be focussed on the following. 1) More profitable use of mineral deposits, increase of mineral reserves to provide a rhythmical pace of mining works for many years (oil, rock and potassium salt, cement stock, etc.). 2) Development and mining of discovered and proved, but not worked deposits (iron, ores, phosphorites, dawsonite, rare earths,etc.) after an appropriate technological and economic evalution and additional increase of their reserves. 3) Detailed study of revealed ore evidences, mineralization zones and sites in order to transform some of them to mineral deposits or occurences. Revision and estimation of geochemical anomalies. 4) Forecast evalution of all the stratigraphic horizons and tectonic elements in the Earth's interior for possible revealing of ore shows, mineral occurences and deposits. 5) Comprehensive petrographic, lithological and geochemical study of the most abundant rocks and minerals in the Earth's interior for possible extraction of useful components from them and their treatment as new mineral stocks. 6) Comprehensive study of mineral waters and brines for their more extensive utilization for balneological purposes and extracting useful chemical components (iodine, bromine).
Azarenko F.S., Boguino V.A., Khomich P.Z.
The current stage of mineral Resources of Belarus and major prospects for further development. pp. 26--41
Abstract: The strenghening of sovereignty and reformation of the national economy pattern of the Republic of Belarus depends to a great extern upon its own mineral resources. Raw material stock as a basis for further economic progress makes the development of mineral resources as well as their efficient use the "hottest" problems in current research. About 4000 various mineral deposits are known within the territory of Belarus. All the deposits can be conditionally subdivided into two groups: deposits ready for industrial mining, and those requiring further exploration. The first group of deposits includes energy resources like oil, brown coal and peat, agrochemical raw materials (potash and rock salt, sapropels, dolomites), various building materials, fresh and mineral underground water.The second group embraces iron ore, rare metals, aluminium, precious metals, phosphorites, gypsum, fibrous kaolin and other deposits and ore occurences. The geological survey "Belarusgeologia" together with the Academy of Sciences of Belarus, Joint Works "Belarusneft" and "Zapadneftegeofizika" have been charged by the Government of the Republic of Belarus to work out the Programme of speeding up prospecting and exploration for the development of mineral resources up to the year of 2000. Under present economic conditions the development of energy resources, diamond exploration, supply of chemical and construction industries with raw materials, evaluation of already known metal ore occurences are of prime importance.
Abramenko V.I., Zinovenko G.V., Piskun L.V.
Cambrian deposits in the East European Platform west and problems of their correlation. pp. 42--55
Abstract: This article is the result of five-year joint Polish-Belarusian work at the problem: litho- and biostratigraphic correlation of Yendian and Cambrian sections in the East European Platform West. Scientists from Poland, Belarus and Lithuania have contributed to research. A series of papers has been published in "Przeglad Geologiczny". The major attention has been given to the solution of three principal problems: substantiation of the Cambrian system lover boundary; more exact determination of the boundary between the lower and the middle series, and correlation at the horizon level. Clear palaeontological and lithology-mineralogical evidences have been obtained or the lower boundary of the Cambrian system; some discrepancies in the boundary position between the Cambrian lower and middle series revealed from Belarus and Poland sequences have been eliminated. Determination of the acritarches, characterized from a section of the borehole Skveriki-1, confirms the analogues of all Belarusian horizons in Cambrian sequences of Poland. The analysis of various deposits of the Baltic series has revealed a peculiar complex of lithofacies and their vertical distribution pattern. The facies distinguished are as follows: 1) relatively deepwater marine, 2) shallow marine, 3) coastal marine, 4) fresh-water basin (plain covered sometimes by sea).
Jakubovskaya T.V.
Problems of the Neogene stratigraphy of Belarus. pp. 56--66
Abstract: The analysis of the composition and time history of floristic complexes obtained from the Miocene section in Belarus and their climate-stratigraphic interpretation have revealed a number of discrepancies between the stratigraphic scheme of Neogene deposits and the general scale.Palaeobotanical data illustrate such climatic events as the Chattian-Aquitanian fall of temperature at the Oligocene and Miocene boundary, three Miocene optima and one Middle-Miocene, Early-Sarmatian pessimum. According to reliable universal datings of these events, the Neogene section of Belarus is referred to the scale of the Western Parathetis, and the following corrections and suplements to the stratigraphic scheme have been elaborated. The Brinev horizon is qualified as a series including deposits of the Upper Oligocene, Lower and partly Upper Miocene. Kaolinite clays overlying coal and variegated clays of the Antopol suite are related to the Middle Miocene. The Upper Miocene includes the Grodno and Slavich suites. The Pliocene part of the Neogene covers the Loza horizon of the lower subdivision and the Detoml and Asoka ones of the upper subdivision.
Uryev I.I., Pushkin V.I., Nekrjata N.S.
Lower Famennian type section in the northwestern part of the Pripyat Trough. pp. 67--73
Abstract: The present paper is a continuation of a series of publications dealing with a comprehensive lithologic and stratigraphic study of the reference sections in the intersalt Lower Famennian deposits of the Pripyat Basin. The intersalt section exposed by the borehole North-Kalinovskaya-1, has been differentiated in detail and described layer-by-layer. The borehole is located in the west of the Chervonaya Sloboda step (northwestern part of the Pripyat Trough). The section has been divided into seven local stratigraphic units (from bottom to top): Kuzmichev Beds, Tonezh Beds, Tremlja Beds, Visha Beds (Zadonsk Horizon), Turov Beds, Drozdov Beds (Yeletsk Horizon) and Petrikov Horizon. The Kuzmichev Beds have been characterized by the middle and upper core portions. They are composed of limestones replaced upwards by shaly-marly sediments. Only the wormtube remains are abundant. A rich Early Zadonian spore assemblage has been found in the section and refers the rocks to the Archaeozonotriletes notatus microspinosus -- A. vasjamicus Zone. The Tonezh Beds include massive and lumpy, frequently algal limestones with abundant organic detritus of brachiopods, ostracodes and echinoderms. A. notatus microspinosus prevails noticeably in the spore assemblage. The Tremlja and Vicha Beds differ from the underlying formations in the higner shale content; these are dark-coloured, thin-bedded, rhythmically alternated marls and shaly limestones. By the spore composition, the Tremlja Beds are referred to the A. notatus microspinosus Zone, while the Visha Beds -- to the Lophozonotriletes zadonicus Zone. The Turov Beds consist of lumpy, frequently shaly limestones with abundant accumulations (occasionally oncolites) of blue-green algae. Fossils of small-shelly Rhynchonellida Evanidisinurostrum (?) polessicum (Linnik), Paromoeopygma (?) turovensis Pushkin sp.nov. (in coll.) never encountered before in the Zadonsk deposits; have been found in the bottom of the Turov Beds. The Drozdov Beds are the thickest in the Intersalt strata. Their bottom part is composed of shaly limestones similar to those in the Turov sediments, and the middle and upper parts -- of genetically different limestones of reefoid aspect. These are detrital-silty, frequently algal limestones containing abundant remains of blue-green and red algae, crinoid segments, shells of brachiopods and gastropods. A rather diverse brachiopod assemblage has been established there, consisting of the Pripyat endemics and the species typical of only the Drozdov Beds from the Yeletsk Horizon. The Petrikov Horizon is composed in the lower part of light-grey reef limestones similar to those occurring in the uppermost Drozdov Beds. Fragments of ramose bryozoans, crinoids and red algae are numerous in limestones. The horizon upper part consists of alternating sulfate clastic and carbonate shaly sediments, which reflect a transition to the late Famennian salty lagoon environment. The spore assemblage typical of the Petrikov sediments as well as of the Archaeozonotriletes famenensis minutus Zone has been identified there. The research described in this publication was made possible in part with Grant No RWR-000 from the International Science Foundation.
Velichkevich F.Ju.
The microevolution aspect of biostratigraphy of the Belarusian Pleistocene deposits. pp. 74--80
Abstract: Comprehensive stratigraphic investigations of the Pleistocene deposits are based on combined biostratigraphic and first of all palaeobotanical methods (palaeocarpological, diatomic, palynological). The objective necessity to carry out biostratigraphic investigations of the Pleistocene sediments of Belarus and the ancient glaciation province of the East-European platform as a whole at a new microevolutional level has recently arisen. Microevolutional researches permit to reveal the events proceeding inside a species or groups of related species unlike the macroevolutional approach, which records the results of evolution at a large scale. Taxa revealed are as a rule short-lived ones of the intraspecies rank and can serve as reliable biostratigraphic evidences for the subdivision of the Pleistocene deposits due to their stenochronism.
Aizberg R.Ye.
Neogaean geodynamic conditions within the territory of Belarus. pp. 81--93
Abstract: The problems of paleogeodynamic reconstructions of the platform basins became within the recent decade a matter for special enquiry. We are dealing, in essence, with a fresh avenue in studying platforms, which is based on using the recent geotectonic conseptions. The peculiarities of the tension (rifting) geodynamic conditions in passive continental margins and intraplate syneclises and troughs are described on the grounds of regional paleogeodynamic models of the East European platform west developed for the Dalslandian, Early Baikalian, Late Baikalian, Hercynian and Recent stages (Aizberg, Gubin et al., 1991). Rifting conditions became evident in the region in the Late Proterozoic, Middle and Late Paleozoic and, apparently, in the Recent time. Late Proterozoic and Paleozoic rifting dissected the EEP west, as well as the platform as a whole, into mesoplates (geoblocks). Late Proterozoic rifting in the region was weak. The dynamic conditions in Volyn-Orsha paleotrough - the most important structure of the EEP west during the Riphean and Early Vendian -- were not diversified and differed from highly diverse typical rifting conditions in the other EEP regions. Hercynian rifting in the Pripyat zone was typical of the extension conditions, was accompanied by listric faulting of the crust, alkali-ultrabasic magmatism, and had a dynamic effect on adjacent structures. The passive continental margin conditions were prevalent on the EEP west during the Early Paleozoic and were due to the Proto-Atlantic (Japetus) Ocean opening. Sediment were deposited in a single Baltic-Dniester basin, which downwarping hypocentres were confined to the Baltic marginal syneclise, Podljassic-Brest depression and Dniester trough. Intraplate geodynamic conditions prevailed in the EEP west during the Late Vendian , Middle and Late Paleozoic, Mesozoic and Cenozoic, and were evidenced by the suprarift depression and syneclise formations. The dynamic connection between newly formed structures and formations and Jurassic-Cretaceous and Cenozoic spreading processes in the Atlantic Ocean and approach of the Eurasian and African platforms became evident in the Kimmerian-Alpine stage.
Naidenkov I.V., Arkhipova A.A., Derevjankin Yu.A.
Tectonic history of the crystalline basement of Belarus from geochronometric data. pp. 94--106
Abstract: The analysis of the radiogenic lead age spectra of zircons from Early-Precambrian rocks of the crystalline basement of Belarus produced by isolated zircon grains (about 90 samples) studied by the kinetic lead-lead method, and few data obtained by the uranium-lead age method permited to revise a succession of the crystalline basement evolution events from a boundary of about 3 mlrd. yrs. B.P. A datting of 2.93 mlrd.yrs. was firstly obtained from garnetbiotite gneisses of the Kulazhin series on the south-east of Belarus and was correlated in time with one of the granulite facies metamorphism phases.A duration of the formation of blastomelonites (from 2.7 to 1.6 mlrd. yrs.) and, respectively, of the scaly-thrusted structure of the Belarusian-Baltic granulite belt was shown. The evidences of at least four stages of tectonic-magmatic activation (2.4 -- 2.2; 2.1 -- 1.9; 1.8 -- 1.6; 1.5 -- 1.3 mlrd. yrs.) were obtained. The questions of the similar age of the Ozery and Okolovo series and of the Rud'ma strata belonging to the Early-Proterozoic zonal polymetamorphic complexes were raised. It was shown that a rigid crystalline basement of platforms is not an absolutely inert system, as it is responsive to various events proceeding in the adjacent areas of Riphean and Phanerozoic tectogenesis.
Zinivenko G.V.
Japetus paleoocean and correlation geological events of the East European platform west. pp. 107--118
Abstract: The existence of the Japetus paleoocean is one the problems of a complicated geology of West Europe. It can not be solved unambiguously. The recent geological and geophysical data obtained from studying ophiolitic belts in the region of Appalachian-Scandinavian Caledonides, oceanic sedimentation, volcanism products, paleomagnetic investigations, location of faunistic provinces provide support for the existence of the paleoocean. The cited geological evidences allow a statement that the Japetus Ocean opened in the Cambrian and its closing started in the Early Ordovician, continued during the Ordovician, Silurian and completed in the Early Devonian. The opening and closing of the Japetus Ocean is shown by geological processes on the East European platform west. The Cambrian trangression on the old platform coincides with the paleoocean opening. Stable sedimentation conditions existed throughout the Cambrian. The first orogenic movements within the Caledonian geosyncline caused faulting and formation of local small-amplitude structures. The maximum increase of amplitudes of faults and local uplifts took place at the end of the Silyrian and beginning of the Devonian, when the paleoocean was completely closed. The latest tectonic movements contributing to the Japetus closing caused the sea regression from the old platform and thrust of Caledonian folded complexes over the old platform.
Levkov E.A., Karabanov A.K.
Neotectonics of Belarus. pp. 119--126
Abstract: The neotectonic (recent) stage covers a geological time interval of about 30 mln yr (since the Late Oligocene to the present). During this period, the pattern of tectonic movements greatly changed: if in the Middle Cenozoic the evolution of tectonic features was a succession of the Hercynian structural pattern, then in the neotectonic period, an inversion took place. The Belarusian Polessie area, which was a place of the most abundant sedimentation, as well as the western part of the region were elevated therewith to 100--150 m and higher. A neotectonic monocline formed as a result was inclined from the Ukrainian Shield and Voronezh Anteclise toward the Baltic Sea basin. The total amplitude of inclination was as high as 200 m within the Belarus territory only. A series of local structures appeared along the monocline, among them -- the Polotsk trough and Berezina embayment. Recently active faults form mainly diagonal and orthogonal systems, the first of them showing mainly horizontal, and the second ones vertical displacements. The development of the recent structural pattern of the Belarus territoty was influenced by the formation of the Ukrainian-Voronezh and Fennoscandian arches and the Baltic system of graben-like lows. The tectonic reconstruction dates back in the most to last 0.3--0.4 mln yr, i.e. to the Middle and Late Pleistocene.
Astapenko V.N.,Karatayev G.I.
On physical properties of the tectonosphere of the Belarus-Baltic region. pp. 127--137
Abstract: In recent years complex geophysical investigations have been carried out in the Belarus-Baltic Region along the profiles Riga-Vitebsk-Bobruysk-Slonim-Sovetsk-Riga and Grodno-Vitebsk. These profiles intersect the main tectonic zones of the region as well as crustal blocks of various deep structure. These series of measurements of the annual increment of gravitational and magnetic fields 20--40 km spaced and magnetotelluric sounding along these profiles have been made in four recent years. The data obtained have made it possible to construct the curves of anomalous annual values of gravitational and magnetic fields and a telluric section of the tectonosphere of this region. The comparison of these results with the data on the Earth's crust types allows a conclusion that the deep faults in the crystalline basement dividing crustal blocks of various types are evidently shown by high gradient of the curves of anomalous annual values of gravitational and magnetic fields as well as by ruptures in the crustal layers with high conductivity. The curve of anomalous annual values of gravitational and magnetic fields is tending to decrease in a transition from crustal blocks showing high thickness of the crust and thick "basaltic" layer and basic rock composition to those with rather thin crust and "basaltic" layer and composed of intermediate rocks. The anomalies of the annual values of gravitational and magnetic fields can be correlated with he Kurzemsk-Polotsk fault zone which confirms its modern tectonic activity. The telluric section of crustal blocks composed of basic rocks and of intermediate rocks differ from each other. In the former case, the telluric section show relatively high conductivity of the crust as a whole which insignificantly varies with depth.
Makhnach A.A., Shimanovich V.M., Kolosov I.L.
Stable isotopes in carbonates of non-salt interlayers in the Upper Famennian evaporite formation of the Pripyat Trough. pp. 138--145
Abstract: The carbon and oxygen isotopic composition of carbonates from non-salt interlayers in the Upper Famennian halogenic formation has been investigated. Studied deposits are characterized by the wide range variation of the isotopic ratios. The d13CPDV values range from -17.5 to +0.8‰, d18OSMOW values - from +19.8 to +36.4‰. Among intrasalt carbonate interlayers four groups of rocks have been found out on the ground of their isotopic composition. A set of the d13C and d18O combinations determined for intersalt interlayers could be realised during the sedimentation and diagenetic carbonate formation occured within sabkha, subaerially exposed insular elevations, on the slopes washed by sea and fresh water and in stagnant zones of deep and shallow depressions with hot brines.
Kuznetsov V.A., Generalova V.A.
Radionuclides and manganese colloid compounds in landscapes. pp. 146--159
Abstract: The compounds of manganese classified with the typomorphic elements of the Belarus territory landscapes are involved in colloidal hypergene processes, show various migration and accumulation forms and are the concentrators of radionuclides. The soil formations have a manganese content ranging from 0.1 • 10-3 to 2.6%, amorphous hydroxides and forms sorbed on them -- from 0.5 to 62.5 % of the bulk content depending on lithological, soil, facies hypergene and other factors. A set of experiments with newly made manganese dioxide precipitate and natural iron-manganese concretions has been carried out to elucidate the participation of manganese colloides in the migration of radionuclides. It has been established that the caesium sorption does not depend on the redox conditions and can be as high as 2.4 mM/1 g Mn(OH)2, and that of strontium show a maximum value of 1.8 mM/1 g Mn(OH)2 in alkaline medium. The caesium sorption proceeds by a mechanism of surface adsorption, that of strontium -- by chemosorption with the formation of manganates. The absorbing capacity of manganese dioxide is 2.5 time higher for strontium and about 50 times less for caesium, as compared to that of iron hydroxides. A separation of manganese and iron in the landcape-geochemical processes proceeding, unequal sorption of radionuclides by colloids are responsible for the differentiation of radionuclides during the sedimentogenesis and pedogenesis, at the geochemical barriers, in the surface and ground water composition, which should be taken into consideration in radiogeochemical monitoring.
Kudelsky A.V., Korkin V.D., Pashkevich V.I., Jasoveev M.G., Sphakov O.N.
Fresh ground water of Belarus (resources and quality). pp. 160--167
Abstract: Fresh ground water resources and the extent of their development are given. Stereometry of an active water exchange zone is outlined. Industrial, domestic and agricultural contamination of ground and artesian water is examined. It is shown that the republic is supplied with adequate fresh ground water resources and ground water quality presents a major problem rather than its quantity. Proposals for providing adequate ground water conservation and rational ground water use have been made.
Nikitin E.A., Khomich P.Z., Levyi M.G.,Drozdov V.A.,Shtefan L.V.
Kimberlite and lamproite rock pipes found in Belarus and their diamondbearing potential. pp. 168--175
Abstract: The pipes recently discovered and studied to some extent in Belarus are shown to be associated with the alkali-ultrabasic formation typical of the ancient platformmargins (cratons) in their petrographic and mineral-petrochemical features, and with hypabyssal kimberlites/lamproites in the facies relationships. Basaltoid varieties, occasionally micaceous, have been found to prevail among kimberlites, Lamproites belong generally to olivine varieties. They are composed of xenotuff, tuff and autolithic breccias. The rocks were completely altered by postmagmatic and exogenic processes. Metasomatic formations are common in the near-contact parts of the pipes. Major rock-forming minerals are olivine of the first and second generation, phlogopite, clinopyroxene (diopside), occasionally melitite, alkali amphibole and pseudoleucite, magnetite, rarely napheline and perovskite. All associate minerals are present, i.e. pyrope, chromspinellid, seldom picroilmenite. Garnets are most abundant, among which eclogite varieties are reported noticeably dominant. Some of them may be reffered to diamond-pyrope deep facies. Furthermore, three diamond crystals have been found for the present. The diamond-bearing potential of the pipes cannot be thus excluded.
Derevjankin Yu.A.
Typochemical pecularities and standard of fineness of gold from Anthropogene sediments of Belarus. pp. 176--181
Abstract: The first data on the composition and standard of fineness of gold from Anthropogene sediments of Belarus are presented. The gold fineness standard ranges from 779 to 999 (the high standard gold being dominant). 5 groups of gold pieces have been tentatively distinguished according to their composition and structure. A conclusion of the polygenetic nature of basic sourcelands is drawn.
Makhnach N.A., Gulis L.F.
Distribution of the superficial and ground waters saturation indices with reference to calcite(by the example of Belarus and adjacent territories of Russia). pp. 185--187
Mikhailov N.D., Krasilshchikova O.A., Tkachuk V.I.
On the genesis of fluorite in the Devonian sequence of the Pripyat Through. pp. 188--190
Pavlovskaya I.E.
Peculiarities of glacioisostatic movements in the Belarusian Lake District. pp. 191--192
Bordon V.Ye., Olkhovik Ye.T.
Element clarks in sedimentary cover of the East European platform west. pp. 193--194
Lukjanenok N.P., Kolpakov V.V.
Gold content of fluvioglacial deposits of Belarus. pp. 195--197
Pap Anatolij Mikhajlovich (to the 70-th birthday anniversary). pp. 201--202
Khotko Zhozef Pavlovich is 70 years old. pp. 203--204
CHRONICLE. pp. 205--209
![[NASB Presidium]](../../graphics/asbbutton.gif){kind=small} Academy |