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1.
Mercury inhomogeneity was found between bottles of the same standard for each of the six U.S.G.S. rock standards tested. Variations between bottles amounted to at least a factor of 2 for four of the six standards. Caution is suggested when using these standards as mercury accuracy checks and as estimators of mercury geochemical abundances or cycles.  相似文献   

2.
Elevated concentrations (0.6–0.9 mg/l) of selenium were detected in the groundwater of a small backfill area at a surface mine in the Powder River Basin, Wyoming. This report focuses on the source of selenium, its modes of occurrence in overburden deposits and backfill groundwater, and its fate. The immediate source of the selenium appeared to be the dissolution of preexisting soluble salts from the unsaturated zone of the overburden. The ultimate source of selenium was probably the oxidation of selenium-bearing pyrite in the geologic past. Overburden was placed partially in the saturated zone of the backfill where, upon resaturation, soluble salts dissolved in the groundwater. Water standing in the pit at the time of backfilling might have contributed to the elevated concentrations of selenium and other solutes. Selenium was found in an ash-rich coal and in clastic sediments in seven different modes of occurrence.The concentration of soluble selenium in the groundwater at this site has been decreasing since monitoring began in late 1982, and at the present rate of decrease, the concentration should drop below the State of Wyoming guideline of 0.05 mg/l for selenium in water intended for use by livestock by about mid-1992. The decrease in soluble selenium concentration may in part be due to microbially assisted reduction of selenate followed by sorption on clays and other sorbents.  相似文献   

3.
The well-defined and intensively studied episode of Se contamination at Kesterson Reservoir (Merced County, California, U.S.A.) provided a unique opportunity to describe the distribution, speciation and geochemical transformations of Se in a variety of geochemical and ecological settings, ranging from permanent ponds to semi-arid grasslands and salt flats. Kesterson Reservoir comprises 500 ha of land contaminated with Se from agricultural drain water. In most places. Se was concentrated in surficial organic detritus and the surficial decimeter of mineral soil. At dry sites, selenate ion predominated below 20 cm depth. Elemental selenium (Se0) also was prominent. The amount of zero-valent Se increased slowly with time. Although selenate is thermodynamically stable in the vadose zone in the presence of oxygen, Se0 is an additional, metastable product of the mineralization of organic selenium. Thiols and inorganic sulfides dramatically increase the solubility of Se0. Decreasing pH inhibits the reaction, explaining the observed decrease in solubility and biological availability of Se in soil and aquatic systems at low pH. Adding thiols or methionine to soil increases the emission of volatile Se compounds several-fold, suggesting that thiols play a major role in the microbial cycling of Se in soil.  相似文献   

4.
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  相似文献   

5.
The pH and fO 2 dependences of the [Se2–]/[S2–] ratio in chloride solutions at 100°, 200° and 300°C are predicted thermodynamically. Under the high fO 2 conditions where sulfate species are dominant in solution, the [Se2–]/[S2–] ratio always increases with increasing pH and/or fO 2. Under the low fO 2 conditions where sulfide species are dominant in solution, the pH and fO 2 dependences of the [Se2–]/[S2–] ratio are seriously affected by the presence of native selenium. With native selenium present, the [Se2–]/[S2–] ratio decreases with increasing fO 2, but almost independent of pH in geologically important pH regions. When native selenium is absent, the [Se2–]/[S2–] ratio is solely a function of pH and independent of fO 2. Combining the above with the pH and fO 2 dependences of 34S value of aqueous sulfur species, we discuss the possible influences of the pH and fO 2 of ore-forming solutions on the relationship between the Se/S ratio and 34S value of hydrothermal sulfide minerals. The results are applied to some Japanese sulfide ore deposits.  相似文献   

6.
中国地质学家李四光与当时苏联地学界来往交流紧密,他对地质学的贡献得到了苏联地质学家的高度评价。1958年,苏联科学院全体大会选举李四光为苏联科学院院士,并授予卡尔宾斯基金质奖章;该奖章是1947年由当时的苏联科学院和俄罗斯科学院共同发起的、对地质科学有突出贡献的科学家最高单人奖励,李四光是第六位获奖人,也是至2017年止唯一获此殊荣的外籍地质学家,他的获奖理由是:在地质、古生物、地层和矿产研究工作的综合贡献。李四光有两部著作在苏联被译成俄文出版,分别是1952年的《中国地质学》和1958年的《中国西北部的旋卷构造》,这两部译作对当时的苏联地质界产生了很大影响,极大地推动了李四光学术思想的广泛认知;"地质无国界",中国地调百年的发展历程也有着俄罗斯地学理论、规范、方法实践的烙印,在新的"一带一路"合作倡议和李四光学术精神传承下,中俄、中国与中亚在地学领域的交流合作将不断深化,硕果累累。   相似文献   

7.
Yongliang Xiong   《Ore Geology Reviews》2003,23(3-4):259-276
In this study, an attempt has been made to assess aqueous speciation of selenium and solubility product constants of common selenides at elevated temperatures (up to 300 °C) by using various extrapolation methods. This study predicts that reduced selenium species are dominant species in many geological processes even under relatively oxidized conditions such as those dictated by the magnetite–hematite buffer. On the basis of extrapolated equilibrium constants and solubility product constants for common Se-bearing mineral phases, critical ∑Se/∑S ratios (molal ratios) in mineralizing fluids are proposed for independent selenium mineralization. The minimum ∑Se/∑S ratios in mineralizing fluids for independent selenium mineralization should be at least 10−6, 10−5 and 10−4 at 100, 200 and 300 °C, respectively. For giant independent selenium deposits such as the La'erma and Qiongmo Au–Se deposits in the western Qingling mountains, and Yutangba Se deposits in Hubei Province, China, the mineralizing fluids have reached much higher ∑Se/∑S ratios ranging from 10−1 to 10−3 at 200 °C. This study also suggests that the equilibrium assemblage of pyrite–ferroselite among the common ore minerals requires the highest ∑Se/∑S ratios in mineralizing fluids, followed in decreasing order by the assemblages of stibnite–antimonselite, galena–clausthalite, cinnabar–tiemannite, and acanthite/argentite–naumannite. The assemblage of pyrite–ferroselite can also be formed under relatively oxidizing conditions where [∑H2Se]/[∑H2S] ratios can be high enough for the formation of independent ferroselite.  相似文献   

8.
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.  相似文献   

9.
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.  相似文献   

10.
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.  相似文献   


11.
研究利用填土废塑料瓶作为横向构件附在加筋土挡墙（MSEWs）中钢带上可行性。配筋中的横向构件对增加抗拔力有重要影响。该加筋系统是由作为纵向构件的钢带和作为横向构件的填土废塑料瓶组成。为更好地研究以填土废塑料瓶作为横向构件对抗拔性能的影响,对一条独立的钢带和分别带有1～7个瓶子的钢带进行了拉拔试验。在不同的法向应力下进行了超过18次的实验室大型拉拔试验（例如拉拔箱尺寸为长1.2 m、宽0.6 m、高1.0 m）来评估新提出的加固元件的性能。试验结果表明,在扁钢带上建立三维空间对提高抗拔阻力影响很大。提高抗拔阻力最有效的方法是在距离S与直径D之比为3的钢带上加入4个横向构件,其平均抗拔阻力约为单独钢带的5倍。有横向构件和无横向构件钢带的极限抗拔阻力随竖向应力的增大而增大。  相似文献   

12.
The Ordovician rocks exposed along the N.S.W. coast, near Bermagui, comprise a sequence of alternating greywacke and shale and a less abundant sequence of alternating chert and detrital beds. The only lithological boundary that can be mapped is the contact between the two sequences and it sheds little light on the large scale structure. However, due to continuity of outcrop, well‐defined vergence zones and abundant younging evidence it is possible to interpret the regional structure.

Two generations of folds (B1 and B2) are recognized and the regional folds, a N/S trending anticlinorium to the east and synclinorium to the west, are interpreted as second generation structures (B2). First generation folds (B1) are refolded by B2 on the limbs of the large B2 structures and are commonly recumbent. In the hinges of the regional B2 folds, B1 axial planes are steeply dipping and the folds instead of being refolded by B2, are more tightly appressed than elsewhere. A model is described to explain these observations.  相似文献   

13.
地球系统科学从20世纪80年代蓬勃兴起。国内外学者普遍认为地球系统科学（Earth System Science）概念是由美国国家航空航天局（NASA）1983年首次正式提出。然而如果我们重温李四光先生遗著,则不难发现早在20世纪20-30年代他就已将系统论引入地质学,提出了诸如构造系统（tectonic system）、大陆车阀说、海水进退规程等等新概念;1970年在他临终前出版的《天文·地质·古生物》,还将地球系统科学研究内容进一步扩大。可以说,系统科学思想贯彻在他的一生论著中,说明我国杰出地质学家李四光才是真正地球系统科学的先驱。李四光先生有诸多超前思维值得传承,他创建的“地质力学”的内容就是现代“系统构造地质学”加“地球系统科学”。   相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
在对恩施地区典型农业活动区——芭蕉、长平和鱼塘坝三地土壤中se元素含量进行调查的基础上,通过与富Se土壤质量标准进行对比,发现除长平地区外,其余两地分别属于富Se和高Se地区,并通过土壤理化性质、形态分析和土壤中所生长的植物进行比较,初步研究了se在土壤一植物体系中迁移转化的规律。结果表明：整体来看,鱼塘坝地区属于超富se地区．植物中se的含量也最高,长平地区属于非富se地区,芭蕉地区则属于中等富se地区;植物对se的吸收受一定的土壤理化性质的影响,不同类型的植物对se的吸收富集相差较大;形态分析研究表明,鱼塘坝地区土壤中生物可利用的se含量较高．而芭蕉地区土壤中残渣态se的比例较高．表现为Se的生物可利用性低于鱼塘坝地区．．  相似文献   

17.
A large number of specimens of Seymouriamorph amphibian, family Discosauriscidae, were collected from the south slopes of the Kuramanskiy Khrebet, Mt. Sarytaypan, 10 km northeast of the settlement of Adrasman, Tadzhik S.S.R. Deposits yielding the fossils consist of about 70 m of effusive sedimentary rocks, the top third being tuffs, tuff sandstones, and tuff breccias, and the remainder being alternating fine-grained sandstones, argillites, and siltstones, of gray, greenish, pink, and black colors. The beds overlie 800 m of tuff lavas and tuff breccias and are overlain by 200 m of-tuff breccias. Fossil leaves are abundant in the lower half of the beds in all lithologic types, but the vertebrates are confined to about 1 m of adjoining layers of fine-grained gray to pink sandstone, and almost black argillite. The fossils consist of complete impressions of skeletons, which will yield much anatomical information. Two genera are represented, the most abundant referrable to the Central European form Discosauriscus. The other is related to the European Leptoverpeton but may be new. These specimens permit correlation of the Sarytaypan deposits with Lower Permian' bedsgqn Czechoslovakia and Germany. Larval forms are by far the most abundant, but the presence of adults affords a reliable comparison of growth stages. New and detailed information of the development of the spinal column will also be forthcoming from further study of the growth stages. Presence of gills in the larvae reaffirms the persistence of an aquatic larval stage in the morphologically reptile-like Seymouriamorpha. — N. Hotton III.  相似文献   

18.
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  相似文献   

19.
Experimental studies have been performed to constrain sulfur behavior during apatite crystallization and to determine sulfur partition coefficient between apatite and melt (KdSapatite/melt) at oxidizing conditions. Crystallization experiments have been conducted with a hydrous rhyolitic melt and different bulk sulfur contents (0.15 to 2 wt.% S) at 900 and 1,000°C, 200 MPa and Δlog =NNO+3.6. The sulfur content in the glass increases with increasing amount of added S. Anhydrite crystallizes for S added = 0.75 wt.% (0.10 and 0.13 wt.% SO3 in glass at 900 and 1,000°C, respectively). The amount of anhydrite increases and the amount of apatite decreases with increasing amount of added sulfur. The sulfur exchange reaction in apatite is influenced by the bulk composition of the melt (e.g., P content). However, changing melt composition has only little effect on KdSapatite/melt for the investigated rhyolitic composition. The KdSapatite/melt does not depend directly on temperature, decreases from 14.2 to 2.7 with increasing S content in glass from SO3=0.03 to 0.19 wt.%, respectively, and can be predicted from the following equation: ln Kd = −0.0025×S in melt (in ppm)+2.9178. The combination of experimental data obtained for rhyolitic and andesitic melts reveals that the sulfur partition coefficient tends toward a value of 2 for high-sulfur content in the glass (>0.2 wt.% SO3). Using S in apatite as proxy for determining S content in melt is promising but additional experimental data are needed to clarify the individual effects of T, , and P and Ca content in the melt on S partitioning.  相似文献   

20.
Coupled S speciation and acid generation resulting from S processing associated with five different microbial treatments, all primarily Acidithiobacillus spp. (i.e. autotrophic S-oxidizers) were evaluated in batch laboratory experiments. Microbial treatments included two culture-adapted strains, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, their consortia and two environmental enrichments from a mine tailings lake that were determined to be >95% Acidithiobacillus spp., by whole-cell fluorescent hybridization. Using batch experiments simulating acidic mine waters with no carbon amendments, acid generation, and S speciation associated with the oxidation of three S substrates (thiosulfate, tetrathionate, and elemental S) were evaluated. Aseptic controls showed no observable pH decrease over the experimental time course (1 month) for all three S compounds examined. In contrast, pH decreased in all microbial treatments from starting pH values of 4 to 2 or less for all three S substrates. Results show a non-linear relationship between the pH dynamics of the batch cultures and their corresponding sulfate concentrations, and indicate how known microbial S processing pathways have opposite impacts, ultimately on pH dynamics. Associated geochemical modeling indicated negligible abiogenic processes contributing to the observed results, indicating strong microbial control of acid generation extending over pH ranges from 4 to less than 2. However, the observed acid generation rates and associated S speciation were both microbial treatment and substrate-specific. Results reveal a number of novel insights regarding microbial catalysis of S oxidation: (1) metabolic diversity in S processing, as evidenced by the observed geochemical signatures in S chemical speciation and rates of acid generation amongst phylogenetically similar organisms (to the genus level); (2) consortial impacts differ from those of individual strain members; (3) environmental enrichments of Acidithiobacillus spp. catalyze different S reaction arrays than pure strain Acidithiobacillus spp.; and (4) microbial catalysis of S reactions involves significant disproportionation tied to substantial H+ consumption, with the formation of as yet, poorly characterized intermediate S species, most likely polythionates and polysulfane monosulfonic acids that are thought to be involved in microbial S storage mechanisms.  相似文献   

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