Volume 20, 4, 2001
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Volume 20, 4, 2001 |
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Minerageny
A.A. Sidorov, A.V. Volkov.Unique ore district of Chukotka (Northeastern Russia). 3
M.V. Goroshko, N.K. Chekantsev.Uranium potential of the South Sinegorsk ore district (Primorye). 12
A.P. Matyunin, V.G. Sakhno, S.I. Dmitruk. A new finding of diamonds in the Khanka massif (Primorye). 31
V.I. Goncharov, V.Ye. Glotov, A.V. Grevtsev. Mineral and fuel energy potential of Northeastern Russia. 35
MorphotectonicsA.P. Kulakov, Ye.A. Myasnikov, S.M. Tashchi, Qiu Shanwen, Wang Xikui, Liu Yunliang, Song Changchun. The transregional lineament Amur-Songhua-Huanghe: morphostructure, evolution, geodynamics. 26
Geochemistry and PetrographyA.Yu. Antonov, C.I. Dril, E.V Bankovskaya. Rb-Sr-isotopic characteristics of the allochthonous and autochthonous Late Mesozoic granitoids from the Stanovoy Range (southern boundary of Aldan shield). 61
G.A. Gonevchuk, V.G Gonevchuk, N.S. Gerasimov, R. Seltmann. Komsomolsk ore district: new geochemical and isotopic geochronological (Rb-Sr) data. 76
Dong-Woo Lee, I.A.Tararin, Kwang-Soo Seo, Byung-Su Lee. Ultramafic rocks from Choongnam Province of South Korea and their comparison with rocks of ophiolite assemblages from accretionary structures. 87
Paleontology and Sedimentology
N.V. Sennikov, T.V. Klets, N.G. Izokh, R.T. Gratsianova, Ye.A. Yelkin, N.K. Bakharev, O.A. Rodina, O.P. Mezentseva. Facial and faunal peculiarities of Givetian alatian ("cheeheilian") beds in the northern part of the Central Asia fold belt. 98
T.D. Zonova, E.A. Yazykova. Representatives of the Inoceramus anglicus group in the Sikhote-Alin and in the Penzshina depression. 116
Anniversaries
K.F. Sergeev (70th birth anniversary). 127
Obituaries
A.A. Vrublevsky (1946-2001). 131
V.V. Onikhimovsky (1914-2001). 132
A.A. Sidorov, A.V. Volkov
Unique ore district of Chukotka (Northeastern Russia)
The unique character of the ore district of Chukotka is characterised. The final stage of mineralization in the area is connected with the Okhotsk-Chukotka volcanic belt. The features of magmatism and ore formation of deposits, most representative of the Maiskiy ore cluster in the area, are considered. Mineralization of the ore cluster depends on metallogeny of structures of the base of the belt. The features of overlapping and mutual relations between gold-disseminated and veined ores are investigated. The pattern of formation of the largest ore deposits of the area is developed.
M.V. Goroshko, N.K. Chekantsev
Uranium potential of the South Sinegorsk ore district (Primorye)
An analysis of the recent geological evidence of the Khanka massif made it possible to identify the South Sinegorsk depression of long (over 1 Ga) development in its southeastern part. The basin controls fluorite-REE deposits of the Voznesensk district and small uranium deposits of the Sinegorsk ore districts. The general characteristics of the depression's uranium potential are given. Uranium mineralization in the depression involved several cycles. Formational division of different-age uranium mineralization is offered. Two uranium formations are distinguished: 1) uranium formation in eusites, and 2) molybdenum-uranium formation in argillisites (hydroglimmerites) in connection with the final stages of Upper Paleozoic magmatism. These formations are major for the referred region. The problems of the erosion section of the ore-bearing structures, and the effect of post-ore magmatism and rupture tectonics on the persistence of mineralization are highlighted. Recommendations are offered for further assessment of the uranium potential of the depression. The idea is advanced that uranium-bearing structures of similar type exist in the southern part of the Far East: in the northern part of the Khanka massif and in the southwestern part of the Bureya massif.
A.P. Matyunin, V.G. Sakhno, S.I. Dmitruk
A new finding of diamonds in the Khanka massif (Primorye)
The paper describes two diamond crystals found in the weathering crust of a pipe anomaly 4 km north-east of the Kurkhanskaya diamond diatreme in kimberlite rocks, where diamond fragments about 1.2 mm in size were found. The new finding is remarkable for one crystal representing a twin growth with strongly marked facets. Another diamond crystal has also well marked facets of growth and solid phase inclusions. In heavy concentrates, the grains of high-chromium spinels were found. They are analogous to those detected in the Kurkhanskaya diamond diatreme, and compositionally they are similar to chromites identified in the growths with diamonds in Yakutia and other diamond pipes of the world.
V.I. Goncharov, V.Ye. Glotov, A.V. Grevtsev
Mineral and fuel energy potential of Northeastern Russia
The results of investigations into the problem of oil, gas and coal potential in Northeastern Russia are summarized in the paper. Qualitative and quantitative characteristics of the energy features of natural hydrocarbons, and also data on their location and distribution environments are given. Methods of possible production of liquid oil products from coals and the use of the inner heat of the Earth for the economic purposes are described. The predictive resource assessment of important for the regional economy fuel-and-energy mineral types is done: hydrocarbons, hard and brown coals, synthetic oil, peat, and thermal waters-. According to the authors' calculations, the geological resources of sedimentary basins of the region are the following: oil - 27,261 million ton, coal of all types - 202,1 billion ton, explored peat resources - 52 million ton. The synthetic hydrocarbon potential of brown coal deposits in the region with the use of the method of hydrogenation of coal reaches 26.4 billion ton. Geothermal resources are represented by petro- and hydrogeothermal ones. Thermal waters of sources and deep sedimentary basins with a temperature higher than 20°C are among the latter.
A.P. Kulakov, Ye.A. Myasnikov, S.M. Tashchi, Qiu Shanwen, Wang Xikui, Liu Yunliang, Song Changchun
The transregional lineament Amur-Songhua-Huanghe: morphostructure, evolution, geodynamics
The co-operative Russian-Chinese morphostructure investigations of the large fault zone of the Eastern margin of Asia - the lineament Amur-Songhua-Huanghe (LASH), which stretches for more than 3,000 km through the territory of Eastern China and the southern part of the Russian Far East, have been carried out. The morphostructure sketch map of the lineament has been compiled, and the main features of its structure, evolutional peculiarities and geodynamics have been studied. For the first time a series of ring morphostructures (RMS) of different type and rank has been established, which are spatially and genetically related to the LASH, and regularities of their structure and evolution have been determined. Regions distinguished by increased geodynamic activity (including seismic activity) have been established that are the areas of intersections of the lineament with the concentric deep-seated faults of the gigantic RMS. The results of investigations testify that the LASH has existed from the Paleozoic and developed inheritably with the repeated phases of tectonic-magmatic activation against the background of a long geological process of the Earth's crust extension in the eastern continental margin. The main features of the recent morphostructure image of the LASH formed in the Late Mesozoic and Cenozoic when systems of great depressions (Bohaiwan Basin, Sunjiang Basin, etc.) and numerous smaller rift structures developed in the lineament zone.
A.Yu. Antonov, C.I. Dril, E.V Bankovskaya
Rb-Sr-isotopic characteristics of the allochthonous and autochthonous Late Mesozoic granitoids from the Stanovoy Range (southern boundary of Aldan shield)
Twenty-nine samples of rocks and minerals of major types from three largest massifs of Late Mesozoic Stanovov Range granitoids (central and northwestern parts of the region) were used for Rb-Sr-isotopic characteristics. They formed in the abyssal, mesoabyssal and hypabyssal depth facies.
This investigation allowed us to define more precisely the Late Mesozoic age of the Stanovoy Range intrusion formations (109-130 MA) and prove the virtually same age of some regional autochthonous granitoids (117-121 MA). All these age values show a very good conformity with the values of K-Ar age (among which the younger values are always absent).
It was revealed that the age of all more SiO2-saturated granitoids among the main varieties of the studied massifs is always more ancient. This allows us to assume its formation (as opposed to the vein granits) not as a result of crystallization differentiation of the initially more mafic magmas, but rather as a consequence of independent smeltings. The formation of the intermediate SiO2-saturated magmatic products resulted from either mixing of the earlier highly SiO2-saturated crust magmas with the later uppermantle basaltic magmas (Tynda massif) or from different- degree granitic magma assimilation of the ancient mafic crust matter (quartz monzonites of Chilchi massif). All of them are showed in a good conformity with our earlier petrological conclusions.
The values of the initial 87Sr/86Sr ratio in the granitoids of all studied Stanovoy Range massifs are low, but these variations are similar, though substantial (from <0.7066 to 0.7080). This indicates the isotopic inhomogeneous and polygeneous pattern of its initial magmas, and also virtually the same substrate (initially low, and then more alkaline due to the influence of the juvenile fluids), where the Mesozoic, both autochthonous and allochthonous granitoid formations developed. In our opinion, they reflect the different degree of the same granite formation process at different depths without considerable vertical magma movements.
G.A. Gonevchuk, V.G Gonevchuk, N.S. Gerasimov, R. Seltmann
Komsomolsk ore district: new geochemical and isotopic geochronological (Rb-Sr) data
The paper offers new, mainly unpublished results of research into the Rb-Sr isotope system and also REE distribution in magmatic rocks and related postmagmatic tin-bearing formations of the Komsomolsk ore district (Russian Far East).
It is suggested that the established distinctions of the initial ratios of strontium isotopes and also REE distribution in nearly coeval (end of Early - beginning of Late Cretaceous) magmatic rocks of different genetic groups - magmatic complexes show primarily different substratum composition of the magmatic chambers.
Dong-Woo Lee, I.A.Tararin, Kwang-Soo Seo, Byung-Su Lee
Ultramafic rocks from Choongnam Province of South Korea and their comparison with rocks of ophiolite assemblages from accretionary structures
Ultramafic rocks from Choongnam Province, Korea, occur as extended discontinuous isolated bodies among the Precambrian gneiss complexes of the Kyonggi Massif. They show NNE direction, parallel to the strike of the Kongju strike-slip fault zone. The majority of ultramafic rocks is serpentinized harzburgites with a small proportion of clinopyroxene, and most of them are partially or nearly completely replaced by serpentine. The rocks are characterized by restricted ranges of mineral composition, which makes them similar to those of tectonic harzburgites in ophiolites. These restricted ranges of refractory mineral composition are consistent with the interpretation that these rocks are residual material left after an episode of partial melting of mantle source. Mineralogical and geochemical comparison shows that harzburgites from Choongnam Province are more similar to those of oceanic peridotites than to ophiolite peridotites from subduction-related active margins. The field evidence, mineralogical and geochemical peculiarities reveal that peridotites from Choongnam Province are mantle assemblages emplaced into the crust by faulting supposedly in the Cretaceous during the North and South China blocks collision and development of the Tan-Lu and Honam fault systems of East Asia.
N.V. Sennikov, T.V. Klets, N.G. Izokh, R.T. Gratsianova, Ye.A. Yelkin, N.K. Bakharev, O.A. Rodina, O.P. Mezentseva
Facial and faunal peculiarities of Givetian alatian ("cheeheilian") beds in the northern part of the Central Asia fold belt
A necessity for synonymization of the earlier employed terms for the Late Givetian taxon of the brachiopods Spirifer cheehiel Kon., Spirifer cheehiel var. alata St., Euryspirifer cheehiel (Kon.), Acrospirifer pseudocheehiel Hou, Euryspirifer pseudocheehiel (Hou) to one name - Euryspirifer alatus (St.) is well-founded. It is suggested that the term "alatian fauna" ("alatian beds") be used for identification of the Late Givetian faunal assemblage instead of the word "cheeheilian fauna" ("cheeheilian beds"). The lithological peculiarities of rocks and faunal characteristics of the mid-Devonian Beisk suite in the North Minusinsk depression are considered. The suite id treated as a typal object of alatian ("cheeheilian") fauna distribution in the Central Asia fold belt. A layer-by-layer description of the condensed section in the upper part of this suite in the south of the North Minusinsk depression is given, and facial settings of its formation are defined. A successive change of paleocommunities of bryozoans, brachiopods, ostracods, conodonts and fishes from alatian beds are analyzed. A portraiture of the identified forms of conodonts and ichthyofossils is presented. A description of three conodont taxons is offered, including those of the two new ones.
T.D. Zonova, E.A. Yazykova
Representatives of the Inoceramus anglicus group in the Sikhote-Alin and Penzshina depression
The general conception about distribution, taxonomy, geochronological age of the Inoceramus anglicus group is offered. A subdivision of the Pacific representatives of the group into three conventional classes according to the morphological features is suggested. A detailed analysis of the Pacific specimens of the third class has been carried out uniting "winged" forms, one part of which is concentrated in the Penzshina depression; and the other one, in the Lower Amur region. The documented data on the composition and location of the species distributed in the Udyl Lake and Bolshaya Silasu River region are presented in detail.