铀钍的地球化学及对地壳演化和生物进化的影响

本文论述了在含挥发份和贫挥发份条件下Ｕ、Ｔｈ的迁移行为及其对地球和行星演化的影响,并阐述了造成地球独特地质演化历史的原因。提出了Ｕ、Ｔｈ在地球中的迁移模式以及该模式对地壳形成、演化的控制作用和对生物发展演化的可能影响。     

Wavelets and the Generalization of the Variogram

The experimental variogram computed in the usual way by the method of moments and the Haar wavelet transform are similar in that they filter data and yield informative summaries that may be interpreted. The variogram filters out constant values; wavelets can filter variation at several spatial scales and thereby provide a richer repertoire for analysis and demand no assumptions other than that of finite variance. This paper compares the two functions, identifying that part of the Haar wavelet transform that gives it its advantages. It goes on to show that the generalized variogram of order k=1, 2, and 3 filters linear, quadratic, and cubic polynomials from the data, respectively, which correspond with more complex wavelets in Daubechies's family. The additional filter coefficients of the latter can reveal features of the data that are not evident in its usual form. Three examples in which data recorded at regular intervals on transects are analyzed illustrate the extended form of the variogram. The apparent periodicity of gilgais in Australia seems to be accentuated as filter coefficients are added, but otherwise the analysis provides no new insight. Analysis of hyerpsectral data with a strong linear trend showed that the wavelet-based variograms filtered it out. Adding filter coefficients in the analysis of the topsoil across the Jurassic scarplands of England changed the upper bound of the variogram; it then resembled the within-class variogram computed by the method of moments. To elucidate these results, we simulated several series of data to represent a random process with values fluctuating about a mean, data with long-range linear trend, data with local trend, and data with stepped transitions. The results suggest that the wavelet variogram can filter out the effects of long-range trend, but not local trend, and of transitions from one class to another, as across boundaries.     

Principles of spatial organization and evolution of the biosphere and the noosphere

In his last lifetime essay, “A Few Words about the Noosphere”, Academician V.I. Vernadsky (1944) wrote that all living organisms on the planet, including man, are integral to the biosphere of the Earth, its material and energy structure and cannot be physically independent of it even for a minute. However, the substrate that generates all living beings and is no less tightly bound to the biosphere has always been characterized by a significant geochemical heterogeneity, traced both in the vertical and in the lateral structure of all geospheres.

The present work is devoted to three most important aspects of modern geochemistry and biogeochemistry:

• — evolution of the ecological and geochemical state of the environment under conditions of a virgin (anthropogenically untouched) biosphere;
• — structural features of the geochemical organization of the modern noosphere;
• — specificity of the interaction of living matter with the environment under increasing anthropogenic load.

On the basis of theoretical concepts of biogeochemistry and geochemical ecology, formulated in the works of V.I. Vernadsky, A.P. Vinogradov, A.E. Fersman, B.B. Polynov, A.I. Perel’man, M.A. Glazovskaya, V.V. Kovalsky, E. Odum, B. Commoner, E.I. Kolchinskii and others, the author puts forward a hypothesis that there exist two qualitatively different stages in the evolution of the biosphere.The first stage is recognized as the period of natural evolution of the biosphere during which it evolves successively into a more complex and more biogeochemically specialized object. In the course of the geological time, this constantly results, on the one hand, in an increase in species diversity and the perfection of individual species, and, on the other hand, to directed improvement and a greater differentiation of the geochemical conditions of the environment. At this stage, the evolution of all systems of the biosphere that were controlled by the mechanisms of self-organization and self-regulation resulted in the establishment of a dynamic equilibrium, which was responsible for the cycling of all essential chemical elements and therefore providing ecologically optimal geochemical conditions in all ecological niches and for all species and biocenoses inhabiting the biosphere at any given moment.The beginning of the second stage is related to the appearance of reason and qualitative changes in the biosphere caused by the goal-directed activity of the human mind, as an entirely new geological force that appeared to be able not only to disrupt the functioning of natural mechanisms of self-regulation and selforganization, but also to transform the environment in the intersts of a single biological species, Homo sapiens. A direct consequence of this change was the uncontrolled transformation of the natural environment, during which the primary structure (geochemical background) created in the course of billions of years was eventually superimposed by a qualitatively new layer of anthropogenically-derived chemical elements and compounds, thus building an interference pattern of a new geochemical field with which practically all modern living organisms are now forced to interact.An outstanding feature of the new evolutionary stage of the natural environment, called by Vernadsky the noosphere, is that biogeochemical changes at this stage proceed at a rate which exceeds that required for the living matter to adapt to these changes. The result is the disruption of the existing parameters of the biological cycle, leading to the emergence of a significant number of endemic diseases of geochemical nature.The proposed approach was used to prove the anthropogenic genesis of existing geochemical endemic diseases and explain the mechanisms of their appearance. In addition, this approach allowed us to develop a new methodology for mapping zones of ecological and geochemical risk and noticeably simplify the procedure of monitoring distribution and prevention of all diseases of geochemical nature.     

On the Age of the Dongtang Formation in the Hengyang Basin of Hunan and the Cretaceous and Tertiary Boundary

Since the coexistence of the Cretaceous and Palaeocene was ascertained in the Hengyang Basin of Hunan in the middle of the 1960's, the Cretaceous and Tertiary boundary has been discussed in several papers, but it still remains controversal. The points at issue are the connotation, stratigraphical position and lateral correlation of the Dongtang (or Chejiang) Formation.     

南海的形成演化与新特提斯在南海的重新活化

南海位于印度板块、欧亚板块和太平洋板块之间,是世界上最大的边缘海,其构造位置处于太平洋构造域和特提斯构造域,地质构造复杂.关于南海形成演化的动力学机制存在有多种不同观点,其中最重要的一个观点是印度板块与欧亚板块的碰撞致使华南地块和印支地块地幔物质沿东南方向蠕动,从而导致南海的海底扩张.从特提斯的演化规律,以及新特提斯的闭合过程来看,南海并不是特提斯洋的残留海,而是新特提斯在闭合过程中配合印度板块与欧亚板块碰撞导致华南地块和印支地块地幔物质东南方向蠕动的动力学机制下,在南海重新活化的结果.     

Estimation of the scale of spatiotemporal variability in the lithological and geochemical characteristics of suspended particulate matter and bottom sediments at the mouth of the Volga River and the adjacent zone of the northern Caspian

Based on the data of synchronous observations of hydrophysical and biogeochemical parameters in the near-mouth and shallow-water areas of the northern Caspian in 2000–2001, the scale of spatiotemporal variability in the following characteristics of the water-bottom system was estimated (1) flow velocity and direction within vortex structures formed by the combined effect of wind, discharge current, and the presence of higher aquatic plants; (2) dependence of the spatial distribution of the content and composition of suspended particulate matter on the hydrodynamic regime of waters and development of phytoplankton; (3) variations in the grain-size, petrographic, mineralogical, and chemical compositions of the upper layer of bottom sediments at several sites in the northern Caspian related to the particular local combination of dominant natural processes; and (4) limits of variability in the group composition of humus compounds in bottom sediments. The acquired data are helpful in estimating the geochemical consequences of a sea level rise and during the planning of preventive environmental protection measures in view of future oil and gas recovery in this region.     

A geodynamic model of the evolution of the Arctic basin and adjacent territories in the Mesozoic and Cenozoic and the outer limit of the Russian Continental Shelf

The tectonic evolution of the Arctic Region in the Mesozoic and Cenozoic is considered with allowance for the Paleozoic stage of evolution of the ancient Arctida continent. A new geodynamic model of the evolution of the Arctic is based on the idea of the development of upper mantle convection beneath the continent caused by subduction of the Pacific lithosphere under the Eurasian and North American lithospheric plates. The structure of the Amerasia and Eurasia basins of the Arctic is shown to have formed progressively due to destruction of the ancient Arctida continent, a retained fragment of which comprises the structural units of the central segment of the Arctic Ocean, including the Lomonosov Ridge, the Alpha-Mendeleev Rise, and the Podvodnikov and Makarov basins. The proposed model is considered to be a scientific substantiation of the updated Russian territorial claim to the UN Commission on the determination of the Limits of the Continental Shelf in the Arctic Region.     

从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返

位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。     

Paleogeography and facies of the central and northeastern parts of the Moscow syneclise in the Devonian

New data on the stratigraphy and composition of the Devonian rocks of the Moscow Syneclise were used. Facies-paleogeographic schemes were compiled for the Lochkovian, Eifelian, Givetian, early-middle Frasnian, late Frasnian, and early-late Famennian evolutionary stages of the Moscow Syneclise. Seven sedimentation cycles were developed due to sealevel fluctuations and structural rearrangements in the paleooceanic basins surrounding the East European Platform at that time. The inference was made on the structural heterogeneity of the platform basement and on differentiated movements as well as on the strike-slip fault nature of some fragments of the basement relative to each other in the Devonian.     

四川盆地中生代地热特征与前陆盆地构造、沉积作用

沉积盆地热体制与油气资源勘探有着密切的联系.基于石油钻井的Ro数据,采用古地温梯度法恢复了四川盆地钻井的最高古地温.结果显示,四川盆地西部、川东南和川东北的钻井,顶部的剥蚀量在3 700 m左右,盆地中部的剥蚀量约3 100 m.钻井古地温梯度在13.2～24.5℃/km之间,古热流在31.2～60.1 mW/m2之间...     

东南沿海及南海新生代火山作用与南海的形成演化

中国东南沿海地区和南海海域新生代火山岩系列、类型和SrNd同位素特征十分相似,具有板内玄武岩的特征。根据南海扩张时代,将新生代的火山岩划分为扩张期前、扩张期和扩张期后3大阶段,并利用原生岩浆推导了软流圈岩石圈的一些深部作用特征。扩张期前（接近扩张期）和扩张期软流圈顶部埋深较浅。从扩张期前（接近扩张期）到扩张期软流圈顶部埋深变浅,隙间熔浆增加,原生岩浆的演化具有前进式裂谷火山作用的演化序列,岩石圈扩张速率变大。从扩张期到扩张期后（直至第四纪）,软流圈顶部埋深逐渐变深,隙间熔浆减少,原生岩浆的演化表现出后退式裂谷火山作用的序列,岩石圈扩张速率逐渐变慢。新生代火山作用显示出的深部作用特征与南海的扩张和闭合一致,这为我们提供了南海形成和演化的深部作用证据。     

南秦岭下地壳组成及岩石圈的拆离俯冲作用

根据新提供的Pb同位素组成及岩石地球化学研究成果，本文进一步证实了位于北秦岭北界的明港地区发育的早中生代安山玄武质火山角砾岩岩筒所携带的下地壳捕虏体属于南秦岭。所恢复的南秦岭下地壳剖面自下而上为：底侵成因的变辉长岩-基性麻粒岩(其中含有榴辉岩及辉石岩的透镜体)-酸性麻粒岩。秦岭造山带总体的岩石因模型为：南秦岭(扬子块体)向北拆离俯冲，北秦岭地壳向华北仰冲，华北岩石因呈楔状插入秦岭造山带，拆离面约在中、下地壳之间。南秦岭俯冲岩片延伸的范围在平面上有可能达到400km。     

Structure of the crust and upper mantle of the Black and Caspian Seas

Many geophysical characteristics of the Caspian and Black Seas' deep basins are similar, having: suboceanic type of the crust, low average seismic velocity, absence of earthquakes and relatively small variation of magnetic anomalies. However, the sediments in the Caspian Sea deep basin are folded whereas in the Black Sea they are approximately horizontal. The Caspian Sea also has a far greater thickness of sediment accumulation.

The deep basins of the Caspian, Black and Mediterranean seas represent a sequence having similar crustal structures but with a decreasing thickness of sediments and consolidated layer, in that order. It is possible that the intensive sinking and accumulation of sediments began earliest in the Caspian Sea and spreaded continuously to the Black Sea and then the Mediterranean Sea. The Caspian and Black Sea deep basins have existed for long time (perhaps from Paleozoic time or even earlier) as areas with a specific and related type of evolution.     

Unity of the national and the international in the socio-cultural development of the peoples of the USSR

International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.     

贵州地表土壤及沉积物中镉的地球化学与环境问题

镉(Cd)是对人体有害的微量元素。镉含量过高会给动植物带来危害,镉过量可导致人体多种疾病或中毒死亡。本文综述了镉的化学性质及其在自然界的分布规律、存在形式及生物地球化学效应,利用区域化探扫面成果资料,特别分析了贵州地表覆盖的土壤和水系沉积物等介质中镉的地球化学分布特征。研究表明,贵州的镉主要分布在碳酸盐岩及其风化的土壤和沉积物中,镉的高含量异常与中低温热液成矿作用中的锌和有机物含量密切相关。镉的化学结合形态有多种,但以可溶态和可交换态形式存在的镉才能具有生物地球化学效应。贵州应重视和防止镉及汞、砷、铅、铊等生命有害元素发生“化学定时炸弹”的可能性。     

Age and origin of detrital zircons from the pre-Permian basements of the Bohemian Massif and the Alps

U-Pb isotopic analyses were made on detrital zircon populations from sandstones and quartzites of the pre-Permian basement in an attempt to shed light on the presedimentary history of the zircons and the age of their primary source rocks. Eight rock samples were collected from the Saxothuringian and Moldanubian parts of the Bohemian Massif, the western part of the Upper Austroalpine Nappes, and the Southern Alps. The heterogeneous populations were separated into fractions of different size, magnetic susceptibility, color, and shape. Because of their typically pitted surface all zircon grains from the sandstones and quartzites appear to be detrital. Only in three samples from the Alps—one from a contact metamorphic aureole—the zircons show surface recrystallization and minor new growth. With the exception of some euhedral crystals in the Saxothuringian quartzites all zircon fractions have highly discordant U-Pb ages. On a concordia diagram their data points scatter slightly around best-fit lines with upper intersections between 2000 and 2300 m.y. From this pattern the following conclusions are reached:

1. A large proportion of the material of the metasedimentary basement rocks in the Bohemian Massif as well as in the Alps derives from one or more sources, about 2000 to 2300 m.y. old.
2. The estimated proportion of detrital zircons with primary ages of 700 to 1500 m.y. is less than 10%.
3. The existence of a regional high-grade metamorphism in the Bohemian Massif as well as in the Alps during 700 to 1500 m.y. can be excluded. From Rb-Sr isotopic data, a metamorphism for the time prior to 1500 m.y. is very unlikely.

The lower intersections of the best-fit lines with the concordia curve cannot be clearly correlated with an episodic disturbance of the U-Pb systems during weathering and sedimentation and/or during regional metamorphism. For the zircons of the Bohemian Massif a disturbing event, about 550 to 600 m.y. ago, is likely. Clear, euhedral, but nevertheless detrital zircons found among the zircon populations of two Saxothuringian quartzites (“Plattenquarzit” of the pre-Ordovician “Arzberger Serie” and Lower Ordovician “FrauenbachQuarzit”) crystallized most probably during the Upper Proterozoic and/or the Assyntian petrogenesis. The highly discordant age pattern of the detrital zircons from the Alps is likely to be the result of the Caledonian and/or Hercynian (=Variscan) metamorphism. Differences in concentration levels of common lead in detrital zircons and the problem of red zircons as indicators of Precambrian origin are discussed.     

On the role of the Hercynian and Alpine thrusts in the Upper Paleozoic rocks of the Central and Eastern Pyrenees

Abstract

The structure of the Pyrenean pre-Hercynian rocks involved in the “Axial Zone” antiformal stack, results from the association of Hercynian cleavage-related folds and Hercynian and Alpine thrusts. Some of these Alpine and Hercynian thrusts separate thrust sheets in which Upper Paleozoic rocks, Devonian and pre-Hercynian Carboniferous, exhibit different lithostratigraphy and internal structure.

In order to know both, the original Devonian facies distribution and the structural characteristics, the effects of the Alpine and the Hercynian thrusts must be considered. If a conceptual restored cross-section is constructed taking into account both the Alpine and Hercynian thrusts, a different Devonian facies distribution is achieved. Devonian carbonatic successions were originally located in a northernmost position, whereas sequences made by alternations of slates and limestones lie in southernmost areas. Moreover, a N-S variation of the Hercynian structural style appears. In the northern units thrusts are synchronous to folding development and they are the most conspicuous structures. In the intermediate units, thrust postdate cleavage-related folds, and in the southernmost units several folding episodes, previous to the thrusts, are well developed.

We present some examples which enable us to discuss the importance of the Hercynian and Alpine thrusts in the reconstruction of the Pyrenean pre-Alpine geology.     

Trace and platinum-group element geochemistry and the development of the Merensky unit of the Western Bushveld complex

Whole-rock samples of the Merensky Unit were analysed for major elements, Cu, Ni, Cr, Co, Eu, Th, U, Cs, and the platinum-group elements Pt, Pd, Rh, Ir and Au. There is a sympathetic variation of Cu, Ni, Co, and S throughout the sequence. Th and U abundances are highest around the Merensky Reef, and their distribution in the rest of the unit reflects the amount of mesostasis. Eu distribution is governed by primary plagioclase. Pt, Pd, Rh, Ir and Au (PM) are concentrated in the Merensky Reef. The relative proportions throughout the unit are Ir2 enrichment trends; interaction of these trends resulted in the Merensky Reef and its attendant mineralization.     

Abundance and distribution of the rare-earth elements and yttrium in the rocks and minerals of the Oka carbonatite complex,Quebec

are-earth (REE) and yttrium abundances were determined, by an ion-exchange-X-ray fluorescence procedure, for whole-rock (14) and mineral (87) samples from the Oka carbonatite complex. Whole-rock and mineral data indicate a trend of total REE + Y enrichment, and relative enrichment in light REE, in the order: ultrafenites < ijolites < okaites. The sövites may show wide variations in total REE + Y concentrations, but relative REE abundance patterns will be similar. The greatest REE and Y concentrations occur in apatite, niocalite, perovskite and pyrochlore. Many of the minerals show europium anomalies (both positive and negative), and these are believed to be the result of closed system competition between the various minerals for divalent Eu. The partition coefficients for mineral pairs are quite variable, indicating that the Oka rocks were emplaced through a wide-range of physicochemical and/or nonequilibrium conditions. A reasonable model for the origin of the complex involves a limited partial melting of mantle material, emplacement of the melt in a magma chamber, crystallization of mafic minerals resulting in a residual liquid which produced ijolite and subsequently okaite, and crystallization of the carbonatites from a volatile-rich, possibly immiscible, phase.