Volume 18, № 3, 1999

Volume 18, № 3, 1999

Geophysics and Seismotectonics
S.V.Soloviyev. Magnetohydrodynamics of the Earth’s core: Particular cases    3
S.V.Kuznetsov. The natural convection in spherical layer with heat source    12
T.K.Zlobin , A.I.Abdurakhmanov, L.M.Zlobina.Prospecting of steam hydrothermal deposits of the Mendeleyev volcano by seismic method    21
R.M. Semenov, L.G. Obukhova, S.P. Serebrennikov.Specification of seismotectonic setting in the area of the Urgal hydro- electric power station (the Far East)    32
O.A.Melnikov, P.N.Sabirov. New data on the present status and last activity of the Yuzhno-Sakhalinsk mud volcano (the Sakhalin Island)     37

Geochemistry and Mineralogy
Yu.D. Zakharov, N.G. Ukhaneva, A.V. Ignatyev, A.M. Popov, T.A. Punina. Preliminary data on the isotope composition of carbon and oxygen in Triassic organogenic carbonates of the Tethyan belt and the marine bioproductivity during Triassic time     47
E.L.Shkolnik, Tang Tanfu, Xue Yaosong, Yu Conglin Results of the investigation of phosphate grains by combined scanning electronic microscope and microanalyser    54
Yu.P.Troshin, O.N.Volynets. Distribution of chalcogens, halogens, gold and silver in the Late Cenozoic volcanics of Kamchatka      60
T.S.Khabibulina, V.A.Trunilina. Crystallomorphology of zircon in granitoids of the Verkhoyansk-Kolyma mesozoides     70

Stratigraphy
V.D. Khudik , K. Amano. New data on the age of the Khoindzhinsky and Verkhneduiskaya suites, Western Sakhalin...76

Geoecology
B.I.Burde. Classification of natural and artificial geologic processes    82

Anniversaries
G.L.Kirillova (to the 60-th birth anniversary)

S.V.Soloviyev
Magnetohydrodynamics of the Earth’s core: Particular cases
The natural convection heat transfer of uncompressed electric conducting fluid in a spherical layer with the Boussinesq approximation is considered. The fluid motion in the magnetic field is the result of natural convection. Three particular cases are under consideration: motion in the core as a result of temperature difference without force of inertia; motion in the core caused by the heat flux without force of inertia; motion in the core resulted from the heat flux without buoyancy force . The influence of the magnetic parameter on the convection intensity and magnetic induction re-generation is analysed. It is concluded that convection motion in the core decreases if magnetic forces are not taken into consideration.

S.V.Kuznetsov
The natural convection in spherical layer related to the heat source
The problem of the natural convection of uncompressed fluid in a spherical layer is discussed in connection with the theory of hydromagnetic dynamo. It is proposed that the layer has an inner heat source and the gravity acceleration has been directed to the centre of the sphere. The motion of the fluid in this layer is generated by the temperature gradient. Rotor of velocity and stream functions have been used to decide this problem. The numerical solution, including the distribution of temperature, stream function and Nusselt numbers, were obtained by using the control volume method.

Zlobin T.K., Abdurakhmanov A.I., Zlobina L.M.
Prospecting of steam hydrothermalL deposits of the Mendeleyev volcano the seismic method (Kunashir Island)
    The results of investigations performed on the Mendeleyev volcano (South Kuril Islands) on the evaluation of perspectivity of areas for steam hydrothermal deposits are described for the first time with the help of a method of earthquake converted waves used in structural seismology. Premises of application of this method in a complex of prospective works are presented. Prospecting criteria were developed which are based on some indications associated with the structural features of crustal deep structure and its internal heterogeneities. These indications are based on the attributance of hydrothermas to the volcano-tectonic structures, distributions of deposits and hydrothermal systems within definite tectonic structures, on the relation between steam hydrothermas and magmatic sources, areas of higher permeability of lithosphere and fault zones, structural features of basement and volcanogenic-sedimentary rocks overlapping it. The seismic investigations made and application of the above mentioned indications allowed us to determine main structural features of the territory under investigation, tectonic faults and internal heterogeneities including magmatic sources related to the genesis of thermal waters . The supposed boundaries of the geothermal region, the structures corresponding to the hydrothermal system and steam hydrothermal deposit were determined on the basis of the obtained data. A perspective scheme for thermal energy waters was compiled as a result of the joint analysis of all the above mentioned criteria. The areas having the greatest interest for discovering steam hydrothermas were also distinguished. The most perspective of them is located between the Kislaya and Lechebnaya rivers, within PK9 area. The described method can be applied to some other similar geothermal fields of the World.

R.M. Semenov, L.G. Obukhova, S.P. Serebrennikov
Prediction of seismic disaster at the Urgal Hydroelectric Station, the Khabarovsk Territory, based on matrix concept of geological-geophysical data
The paper analyzes quantitative characteristics of the geological and geophysical data on the Earth’s crust within the Urgal hydroelectric power station area, the Khabarovsk territory. These characteristics were studied in epicentral zones of large earthquakes recognized here. Prediction of seismic hazard of the territory under study is made for the first time on the basis of an expert system, that makes it possible to determine the geological and geophysical fields, reflecting processes that occur in the Earth’s crust, in the class of non-linear functions, as well to distinguish zones with similar geological and geophysical conditions and consequently seismic hazard. The map of PEF (probable earthquake foci) zone compiled on the basis of quantitative features of the geological and geophysical data pertaining the Earth’s crust has been compared with that previously compiled on the qualitative basis. Both maps show much in common.

O.A.Melnikov, P.N.Sibirov
New data on the present status and former activity of the Yuzhno-Sakhalinsk mud volcano (the Sakhalin Island)
The newly appeared mud field has been discovered as a result of investigation of the Yuzhno-Sakhalinsk mud volcano in spring and summer of 1997. This fact indicates that, probably, the last active eruption of volcano took place in autumn of 1996. There were found six submeridionally oriented groups of mud gryphons (every group consisting of 10-15 gryphons), having thge following three different modifications: 1) high (up to 0,5m), having steeply dipping flanks, active (1); 2) low, gentle, active (4); 3) hilly low, "extinct"(1). Besides, two groups from four are low, gentle active gryphons, being discovered for the first time far away, among the old forest, outside modern mud fields of the Yuzhno-Sakhalinsk volcano - 200-250 m to the north of the central part of the volcano. Besides, obvious traces of mud fields of a more ancient volcano 9as compared to the modern Yuzhno-Sakhalinsk mud volcano) have been discovered southward of the modern active volcano. On the covered with forest volcano, there are two age generations of trees, distinguishing by length and variety of species. Located in the central upper part of the hill, the first generation consists of alders (35-45 years old, 5-8m high, 7-12 cm in diameter)., The second age generation located on the slopes of the hill is composed of firs and silver firs (70-122 years old, 15-21m high and 28-46cm in diameter). The age of the trees was estimated with the tree ring analysis. The first age generation is generally adequate to the mud field of the last active eruption of ancient volcano (acting probably in 1930-1940). The second age generation corresponds to a more ancient mud field originated at the end of the last and beginning of this century. Studying the above-mentioned volcanoes (disappearance of mud fields of modern volcanoes and decreasing the activity of ancient volcanoes) shows that the activity of mud volcanoes is dying in XX century. So, as we know, there is a genetical relationship between mud volcanoes and Tim-Poronaisk (Central Sakhalin) overthrust. This overtrust, in its turn, depends on modern seismicity. So, the istablished obvious reduction of the mud volcano activity, probably is a result of decreasing seismicity that, in its turn, depends on movements along the above-mentioned fault. In order to confirm or refute this conclusion there it is necessary to monitor the Yuzhno-Sakhalinsk volcano activity.

Yu.D. Zakharov, N.G. Ukhaneva, A.V. Ignatyev, A.M. Popov, T.A. Punina
Preliminary data on the isotope composition of carbon and oxygen in Triassic organogenic carbonates of the Tethyan belt and the marine bioproductivity during Triassic time
Original data on stable carbon and oxygen isotopes of the Lower Triassic of South Primorye, Middle-Upper Triassic of South Sikhote-Alin, Salzrkammergut, a stratotype region for the Upper Triassic stages in the North Alps, support an idea according to which the biologic sea productivity in the Tethyan realm during the Early Mesozoic was significantly higher as compared with that of the Boreal realm. Some peculiarities of the Tethyan biota evolution just after considerable decreasing the sea biologic productivity at the Permian/Triassic boundary are discussed. New data evidence for the existence of Middle Olenekian, Late Carnian and Early Norian climatic optimums during the Early Mesozoic and agree with a hypothesis [4] on the origibation of some Triassic rocks of the Koryak Upland from low latitudes.

E.L.Shkolnik, Tang Tanfu, Xue Yaosong, Yu Conglin
Results of the investigation of phosphate grains by combined scanning electronic microscope and microanalyser
Different in nature phosphate grains of phosphorites have been studied by using a combined scanning electronic microscope and microanalyser. By chance, granular phosphorite from Abu Tartur, Egypt, has been chosen as an object for study. It consists of two main types of grains - phosphatized microbial mats and phosphatized shells of invertebrates. We have found marked differences in geochemical characteristics of these grain types. In the mat grains phosphorus contents are usually higher, pyritization is poorer, and rock element admixtures are lower. Pyritization and correspondingly intensive pyrite oxidation appear to occur in greater part in grains from shell fragments. We have determined unique high contents of samarium that at certain interdependency with phosphorus reach 5%. So the mat grains are more often enriched in it. Features of REE differentiation within a single grain -a shell - are outlined when in the central parts lanthanum is concentrated and on grain periphery samarium is. The use of such technique makes it possible to obtain a significant additional information about the phosphatogenesis processes and may be important for solving the problems of enrichment of economic ores.

Yu.P.Troshin, O.N.Volynets
Distribution of chalcogens, halogens, gold and silver in the Late Cenozoic volcanics of Kamchatka
The paper presents the first evaluation and specified clarke contents of Se, Те,Cl, Ag, S, Au, F in the Late Cenozoic volcanic lavas of the Kamchatka segment of the Kuril-Kamchatka island arc. They differ from the available clarkes in basalts of mid-oceanic ridges and other geodynamic settings. As compared with the contents in basalts of the mid-oceanic ridges, in the lavas of Kamchatka the contents of S are 5-8-times, Se 2-3-times, Te and Ag 1.1-1.5-times lower, those of F are the same or slightly higher, and Cl and Au are much higher. From the eastern volcanic belt through the Median Ridge to western Kamchatka and from the island arc lavas to the rift ones there is observed a decrease in the median values of S, Se, Те, Cl in basalts and andesites and a growth of contents of, Ag and Ag/Au ratio. Arithmetical mean of Те content in the same series is raising due to some samples with anomalously high contents of this element. The arithmetical means of S contents in island arc volcanics of Kamchatka amount to 140-265 ppm versus 60-224 ppm in rift volcanics; Cl 157-200ppm versus 59-114 ppm; F 285-452 ppm versus 847-1209 ppm; Se - 71-85 ppm versus 55-65 ppm; Те - 2.3-2.7 ppm versus 3.1-4.1 ppm; Ag - 19-44 versus 24-31 ppm; Au - 2.6-11.3 ppm versus 3.6-5.4 ppm. The observed compositional variations are due to a large influence of the subducted oceanic plate composition enriched -in Cl, S and Se on the composition of magmatic melts of the Eastern volcanic belt and predominating influence of the upper mantle composition (source of K, F and Те) on the composition of Western Kamchatka magmas. The distribution of Au in regional plan is correlated with the distribution of Cl, whereas Ag with that of F.The increased clarke of Au and reduced clarke of Ag in volcanics of Kamchatka agrees well with the increased Au/Ag ratio in gold and gold-silver deposits of the region.

T.S.Khabibulina, V.A.Trunilina
Crystallomorphology of zircon in granitoids of the Verkhoyansk-Kolyma mesozoides
Pyupin and Turco’s (1972,1980) typological diagrams have been used for studying crystallomorphology of zircon in granitic rocks of different granitoid associations of the Verkhoyansk-Kolyma mesozoides: tonalite-granodiorite-plagiogranite, diorite-granodiorite-granite, granodiorite-granite, granite-leucogranite, alkali and alkali-feldspar granites. Special populations with zircon have been established in them. Zircon granitoids of the mantle-crustal (two first associations), and crustal (two second associations), and alkali and alkali-feldspar granitеs are most clearly differentiated. The obtained results may be recommended for systematization of the granitic rocks of the region and reconstruction of the parameters of their crystallization.

V.D. Khudik , K. Amando
New data on the age of the Khoindzhinsky and Verkhneduiskaya suites, Western Sakhalin
The article presents the results of the study of Bivalve molluscan fauna from the marine deposits at the Khoindzhinsky reference section in the Western Sakhalin where the Verkhneduiskaya suite is typically cropped out. The fauna from the middle part of the Verkhneduiskaya suite has been analysed. The analysis of this fauna and the K-Ar age (17.6 ± 0.9 Ma) obtained for the basaltic andesite of the Khoindzhinsky suite suggests the Lower Miocene age for the deposits underlying the Verkhneduiskaya suite. These results specify the position of the suite in the general scheme of the regional stratigraphy. We show an importance of the analysis of the Miocene molluscan association of Sakhalin for determination of the faunal age, and for the elucidation of the geological development of Western Sakhalin at the end of the Early and beginning of the Middle Miocene.

B.I.Burde
Classification of natural and artificial geologic processes
Natural and artificial geologic processes are considered as short-term ones if their results and products can be observed or measured. Consequently, these processes influence on the life conditions and economic activity. The classification suggested, first of all, seems to cover all surface and deep-structure geologic events, in contrast to existing practical classifications. Secondly, it is based on the direct comparison of natural and artificial processes. This approach allows to reveal the human activity as a geologic agent in all its aspects. The classification has a 5-level hierarchical order and contains more than 300 subdivisions in all levels. For practical use, for example, in geo-environmental research, 6-digit code term-dictionaries (classifiers) are compiled on the base of this classification.

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