Regional development and the natural resources of the U.S.S.R.

The recent experience of the rising cost of exploiting new material resources in the U.S.S.R. has led to exploration of alternative methods, particularly greater intensification of exploitation. The regional variations in the balance between intensive and extensive methods is considerable and is consequently an important aspect of Soviet geographical research. This paper discusses the criteria and methodology for this crucial economic/resource regionalization of the U.S.S.R.     

Development of geological research in U.S.S.R Academy of Sciences and U.S.S.R. Ministry of Geology and Mineral Reserves

On October 12, 1962, a joint session of the Presidium of the U.S.S.R. Academy of Sciences and the Collegium of the U.S.S.R. Ministry of Geology and Mineral Reserves adopted a resolution “On the present state of the geological sciences in the U.S.S.R. Academy of Sciences and the U. S. S. R. Ministry of Geology and Mineral Reserves and their prospects for the future.” Important contributions of Russian geologists are acknowledged, but attention is drawn to many shortcomings. Future goals of geological study and work are given in detail. Twenty-one lines of research to be concentrated on are given, covering all phases of geology, geophysics, and geochemistry. In discussing the failings of the geological profession in Russia, it is of interest to note the following comment: “Geological research in other countries is still insufficiently studied and applied, and we are not making adequate use of geologic information from abroad.” The list of the Russian geologists' shortcomings sounds vaguely familiar. —J. R. Hayes     

Thermal waters in the U.S.S.R.

A very interesting and informative paper on widespread occurrence of a thermal hydrosphere. Geothermal power uses are discussed. Distribution of heated waters, some up to 150° C is discussed in considerable detail, especially with reference to possible power utilization of the geothermal energy. Seven hydrothermal regions of the U.S.S.R. are discussed and delineated. Chemical quality of waters is referred to. There is a summary listing of locations in the U.S.S.R. where thermal waters could be utilized for generation of electric power. — B. N. Cooper.     

Tufa formation in Tatar A.S.S.R

Tufa occurs widely in the Tatar A.S.S.R. and adjacent republics. It is associated with springs escaping from aquifers in deposits of Permian age. No tufa deposits were observed in the region where Jurassic and later deposits are developed. Tufa deposits occur because of a breakdown of calcium bicarbonate to CaCO₃, water and CO₂. The presence of organic matter and phosphorous inhibits this reaction, accounting in part for the lack of tufa deposition in the other regions. It appears also that tufa deposition is favored by 1) increase of water surface, hence increased evaporation and CaCO₃ concentration and 2) slopes where argillaceous material is present.—J.J. Finney     

PROGRESS OF GEOLOGICAL STUDIES AT THE ACADEMY OF SCIENCES OF THE U.S.S.R.

Progress report deals with: 1) Geochronology — potassium-argon — principally Precambrian. Gives dates on Precambrian of Baltic Shield including eastern Sweden, Northeastern Norway, Finland, Karelia, and Kola Peninsula. Gives a correlation of the Precambrian for the entire European U.S.S.R. 2) Depth and origin of magmatic ore deposits using reconstructed erosion surfaces for the major periods of mineralization. The depth zones of ore formation of American and European theories is questioned. 3) Tectonic mapping in crustal studies. And in this conjunction 4) Bathy-metric map of the Pacific has been prepared, conspicuous features are major tectonic and volcanic forms of the ocean bottom, as well as minor detail. Brief mention is made of ore deposits from the ocean. 5) “Weathering Crust” studies of subaerial weathering erosion and deposition, mainly of ancient crusts. 6) Study on the origin and distribution of “agricultural areas”, mainly phosphates. 7) Compilation of a Manual of Minerals now underway.--M.A. Klugman.     

Distribution of crinoidal remains in the Upper Cretaceous of the U.S.S.R.

A list of all Upper Cretaceous sea-lilies known from the U.S.S.R. is given. Their stratigraphic and geographic distributions are discussed. Three paleogeographic subprovinces, the south-eastern, the northern and the south-western, can be distinguished in the Mediterranean paleobiogeographic province of the U.S.S.R. based on the development and distribution of the Upper Cretaceous crinoids.     

GEOBOTANICAL MAP OF THE U.S.S.R.

A newly compiled geobotanical map of the U.S.S.R. scale 1:4,000,000 is described. Two hundred and ten categories of vegetation are mapped, classified under 15 major groups. The relation of the mapped vegetation units to climate, soil, ground condition (permafrost), watersheds, and major geomorphic features is emphasized. -- M. Russell.     

Socio-economic geography in the U.S.S.R.

A major field of research since the 1920s has been methods and theories of economic regionalization. The territorial-production complex is now recognized as a key developmental tool within the framework of economic-planning regions. Recently, there has been a more marked growth of study into problems of natural-resource development, social progress and change in the U.S.S.R. as well as into the spatial structure of other nations, particularly other socialist countries and non-socialist developing countries.     

Crustal investigations of the U.S.S.R. by means of earthquake-generated converted waves

The method of earthquake-generated converted waves which is based on the simultaneous recording of longitudinal (P), transverse (S) and converted (PS and SP) waves has been used in the U.S.S.R. since 1956. Converted phases generated at crustal and upper-mantle discontinuities in the seismic focal area are carefully analyzed. In this paper some dynamic characteristics of transmitted PS- and SP-waves arising at different types of boundaries are described.

From a comparison of the properties of the recorded converted waves with the results of theoretical computations conclusions can be drawn with regard to the possible structure of the “exchange” (conversion) boundaries. Seismic cross-sections are presented which illustrate the high effectiveness of the method in regional investigations of crustal structure. Owing to its significance and the multitude of observations (over 22,000 km of observation lines) the method is one of the principal seismic techniques used in the U.S.S.R. which give quantitative information on crustal layering.     

Structure of the earth''s crust on the territory of the U.S.S.R.

The compilation of statistical data for 269 seismic crustal sections (total length: 81,000 km) which are available in the U.S.S.R. has shown that the preliminary conclusions drawn on relations between the elevation of the surface relief and Bouguer anomalies on one hand and crustal thickness (depth to the M-discontinuity) on the other hand are not fulfilled for the continental part of the U.S.S.R. The level of isostatic compensation has been found to be much deeper than the base of the earth's crust due to density inhomogeneities of the crust and upper mantle down to a depth of 150 km.

The results of seismic investigations have revealed a great diversity of relations between shallow geological and deep crustal structures:

Changes in the relief of the M-discontinuity have been found within the ancient platforms which are conformable with the Precambrian structures and which can exceed 20 km. In the North Caspian syneclise, extended areas devoid of the “granitic” layer have been discovered for the first time in continents. The crust was found to be thicker in the syneclises and anteclises of the Turanian EpiHercynian plate. In the West Siberian platforms these relations are reversed to a great extent.

Substantial differences in crustal structure and thickness were found in the crust of the Palaeo zoides and Mesozoides. Regions of substantial neotectonic activity in the Tien-Shan Palaeozoides do not greatly differ in crustal thickness if compared to the Kazakhstan Palaeozoides which were little active in Cenozoic time. The same is true for the South Siberian Palaeozoides.

The Alpides of the southern areas in the U.S.S.R. display a sharply differing surface relief and a strongly varying crustal structure. Mountains with roots (Greater Caucasus, Crimea) and without roots (Kopet-Dagh, Lesser Caucasus) were found there.

The Cenozoides of the Far East are characterized by a rugged topography of the M-discontinuity, a thinner crust and a less-pronounced “granitic” layer. A relatively small thickness of the crust was discovered in the Baikal rift zone.

The effective thickness of the magnetized domains of the crust as well as other calculations show that the temperature at the depth of the M-discontinuity (i.e., at depths of 40–50 km) is not higher than 300–400° C for most parts of the U.S.S.R.     

Decisions of the Standing Stratigraphic Commission on Ordovician and Silurian of U.S.S.R.

The Committee on Ordovician and Silurian Stratigraphy of the U. S. S. R. defines a number of time-stratigraphic subdivisions of the Russian Ordovician and Silurian Systems. — C.G. Tillman.     

Zircon U-Pb-Hf Isotopic Systematics and Geochemistry of the Granites in the Wurinitu Molybdenum Deposit, Inner Mongolia, China: Implications for Tectonic Setting and Genetic Type of Mineralization

The Wurinitu Mo deposit is one of the newly found molybdenum deposits in the southwestern part of the late Paleozoic–Mesozoic Erenhot–Dong-Ujimqin metallogenic belt(S-EDMB),Inner Mongolia,China. In the present study,the mineralization age of the Wurinitu deposit is constrained to 137.3 ± 1.3 to 131.9 ± 1.5 Ma based on a combination of the laser ablation–inductively coupled plasma–mass spectrometry(LA–ICP–MS) zircon U–Pb dating of the mineralization related fine-grained monzonitic granite and the post-mineralization granite porphyry. The results of zircon Lu–Hf isotopes,combined with the geochemical characteristics of the granites in the S-EDMB,suggest that the Wurinitu Mo deposit was formed in an extensional environment in relation to the subduction of the Paleo-Pacific plate in late Mesozoic. The Wurinitu deposit shares similarities with the classical Climaxtype porphyry molybdenum deposits in tectonic setting,mineral assemblages,and metal zonation.     

FORMATION OF COAL DURING THE CRETACEOUS PERIOD AND ITS ROLE IN THE GLOBAL PROCESSES OF COAL ACCUMULATION

P. I. Stepanov suggested that during the Cretaceous there probably took place a considerable accumulation of coal, although that time was always considered to have been a period of attenuation of coal accumulation. The analysis of facies of the Cretaceous deposits in the far east maritime region of the U. S. S. R. as well as of those of Alaska led the author to conclude that coal accumulation during the Cretaceous was tremendous. This conjecture has now been confirmed: the new estimate of coal reserves of the U. S. S. R. has shown the Cretaceous Lena coalfield to be the largest in the world. Tremendous reserves of coal are also concentrated in the Bureya, Maritime, Anadyr and Sakhalin Cretaceous coal bearing basins of the U. S. S. R. in the Ryōseki basin of Japan and in the Cretaceous coal deposits of North America, particularly in Alaska where a major coalfield very likely exists. Thus it may now be considered that during the Cretaceous there accumulated reserves of coal comparable in immensity to those accumulated during the Tertiary and undoubtedly much larger than those of the Permian, Carboniferous and Jurassic. It may be asserted that rate of coal accumulation kept ever increasing in the course of geological time, and the Cretaceous may be regarded as a period of very intensive coal accumulation. Following up Stepanov's idea we can point out the knots of Cretaceous coal accumulation: Lena, Alaska, Anadyr, Sakhalin — Maritime. The new data on the Cretaceous coal accumulation should be taken into account in any reconstruction of the history of geological development of the earth and of the evolution of the organic world. --Author's English Summary.     

Distribution of regional metamorphism fades in U.S.S.R.

A detailed classification of regional metamorphic rock facies is presented along with the results of compiling a small scale Map of Metamorphic Facies of U.S.S.R. It is demonstrated that typical metamorphic complexes are associated with certain large structural elements of the crust. The aspects of metamorphism are used in identifying the areas of ancient platforms, two types of mobile belts, and two types of high pressure zones at the junction of major structures of different degrees of stability.—Author     

Decisions of the Standing Stratigraphic Commission on Paleogene of U.S.S.R.

The committee on the Paleogene of the U. S. S. R. presents a tabulation of the lithologic and faunal characteristics of a complete Paleogene section in the Crimea. The Committee proposes that this section serve as a new type of section for the Paleogene of Europe. — C.G. Tillman.     

Seismic studies of low-velocity layers and horizontal inhomogeneities within the crust and upper mantle on the territory of the U.S.S.R.

Recent seismological studies of low-velocity layers in the U.S.S.R. have led to the development of new methods of investigation. The most important results obtained are presented in this paper. Several new techniques of record treatment and advanced computer programs make it possible to solve two-dimensional problems of seismic wave propagation in complex media and to outline zones of velocity inversion in the crust and mantle of many regions in the U.S.S.R.Zones of this type seem to occur only locally and are typical of some particular geostructures. Lateral inhomogeneities are also found to be closely related to geological features. Their depths sometimes can reach 300–400 km.     

New genetic type of rare-earth mineralization in Precambrian migmatites of European U.S.S.R.

Rare earth mineralization, in the form of xenotime and monazite, occurs along tear faults at an unidentified locality in the Precambrian terrane of European part U. S. S. R. The petrographic and geologic relationships of the last rocks appear to reflect Mg-Fe metasomatism followed by metasomatisrn. The rare earth mineralization appears to have accompanied the K metasomatism. Chemical analyses are presented for one xenotime and two monazites; emission and X-ray spectroscopic analyses are presented for the xenotime. — R.V. Dietrich.     

北山地区中生代岩浆活动与成矿构造背景分析

中亚造山带是古亚洲洋演化与最终消亡的产物。北山地区处于该造山带中段南部,是中国重要的铜、钼、金、铁多金属成矿带。北山地区在晚古生代—早中生代曾发生过2次碰撞造山作用,一次发生于晚古生代末,与古亚洲洋的最终闭合有关;另一次发生于早中生代三叠纪,与北山南带发育的石炭纪一二叠纪裂谷封闭有关。因此,从时间演化看,中生代三叠纪北山地区为碰撞-碰撞后造山阶段,发育大规模剪切带和强烈的岩浆活动及伴生的金属成矿作用。北山地区中生代岩浆活动以深成侵入相发育并缺失相应的喷出相为特征;岩石类型以中酸性侵入岩为主,基性侵入岩局部可见,S、I、A型花岗岩均有产出。与中生代岩浆活动有关的矿床类型主要包括与I-A型花岗岩伴生的斑岩钼矿床、与S型花岗岩伴生的钨(锡)矿床、与中酸性侵入体有关的矽卡岩型金、银铜铅锌多金属矿床和与中酸性侵入体有关并受剪切带控制的金矿床。中生代印支期是该地区最晚一次大规模岩浆活动与金属成矿时期,其发育的范围、规模和强度均比原来认识的要广泛的多,值得进一步关注。     

U–Pb and Re–Os Geochronology of the Tongcun Molybdenum Deposit and Zhilingtou Gold‐Silver Deposit in Zhejiang Province,Southeast China,and Its Geological Implications

Mesozoic ore deposits in Zhejiang Province, Southeast China, are divided into the northwestern and southeastern Zhejiang metallogenic belts along the Jiangshan–Shaoxing Fault. The metal ore deposits found in these belts are epithermal Au–Ag deposits, hydrothermal‐vein Ag–Pb–Zn deposits, porphyry–skarn Mo (Fe) deposits, and vein‐type Mo deposits. There is a close spatial–temporal relationship between the Mesozoic ore deposits and Mesozoic volcanic–intrusive complexes. Zircon U–Pb dating of the ore‐related intrusive rocks and molybdenite Re–Os dating from two typical deposits (Tongcun Mo deposit and Zhilingtou Au–Ag deposit) in the two metallogenic belts show the early and late Yanshanian ages for mineralization. SIMS U–Pb data of zircons from the Tongcun Mo deposit and Zhilingtou Au–Ag deposit indicate that the host granitoids crystallized at 169.7 ± 9.7 Ma (2σ) and 113.6 ± 1 Ma (2σ), respectively. Re–Os analysis of six molybdenite samples from the Tongcun Mo deposit yields an isochron age of 163.9 ± 1.9 Ma (2σ). Re–Os analyses of five molybdenite samples from the porphyry Mo orebodies of the Zhilingtou Au‐Ag deposit yield an isochron age of 110.1 ± 1.8 Ma (2σ). Our results suggest that the metal mineralization in the Zhejiang Province, southeast China formed during at least two stages, i.e., Middle Jurassic and Early Cretaceous, coeval with the granitic magmatism.     

福建中生代钼矿的辉钼矿矿物学特征

福建中生代钼矿分布广泛, 并伴生有一定的铼.通过系统研究福建中生代钼矿基本特征, 总结出主要有斑岩型、岩浆期后热液型、火山热液型、构造角砾岩型(热液石英脉型)及少量矽卡岩型, 选择坪地、上西坑、罗卜岭、马坑等4个典型钼矿进行重点研究.在野外地质调查、岩相学的基础上, 进行了矿相学及辉钼矿矿石矿物学的系统研究, 得出福建中生代钼矿中辉钼矿的晶体形态主要表现为颗粒较大(粗到中细粒), 结晶度高, 多呈片状、鳞片状、局部板状, 多色性明显, 个别矿区辉钼矿颗粒较小, 结晶较差, 多色性不明显; 辉钼矿多型主要为2H, 少量2H+3R型、3R型; 辉钼矿矿物化学成分中微量杂质元素(包括Re含量, 一般为(N~N×100)×10-6, 并以(N~N×10)×10-6为主)较低.本区辉钼矿的这些矿物学特征说明其形成时的温度条件较高, 多为中高温环境, 其物源可能是壳幔混染源, 且以壳源为主; 中生代钼成矿在福建省内具普遍性, 辉钼矿中的Re作为有益的伴生元素具有一定的综合利用价值.