广东麒麟绿钙闪石巨晶的地球化学特征

本文对罕见的幔源绿钙闪石巨晶进行了综合的地球化学分析，主要元素，稀土微量元素和Ｓｒ，Ｎｄ同位素的特征表明；绿钙闪石巨晶是碱性玄武岩浆在地幔条件下的结晶产物；相对于寄主玄武岩，绿钙闪石巨晶均属捕虏晶，它们与共存的橄榄岩包体无成因联系，其形成可能与共存的黑色包体有关。     

Dependence of the spins of supermassive black holes in quasars on their cosmological redshifts

Data on the dependences of the masses and bolometric luminosities of Active Galactic Nuclei on their cosmological redshifts are used to determine the redshift dependences of their X-ray luminosities and the kinetic powers of their relativistic jets. These results are used, in turn, to obtain the redshift dependence of the spins of the central supermassive black holes.     

Metasomatic origin of some of the eclogite-bearing carbonate rocks in the Dabie mountain region, China

Carbonate rocks are one of the major hosts to eclogite in the Mt. Dabie region. Eclogite bodies enclosed in the carbonate rocks occur mostly as knobs, ovoids and lenses measuring centimeters to tens of centimeters in size. The bodies have been intensely carbonatized and usually have transitional contacts with their carbonate hosts. The carbonate rocks have abundant relics of eclogite minerals and their retrogressive derivatives. The REE patterns of the carbonate rocks are characterized by the absence of negative Ce anomaly. These features suggest that a considerable portion of the eclogite-bearing carbonate rocks in the Mt. Dabie region was produced by carbonatization of eclogites and their retrogressive derivatives. These carbonate rocks suffered deformation and recrystallization after their formation. This research project was financially supported by the Ministry of Geology and Mineral Resources (Project No. 9501102-04-1).     

上扬子地台中奥陶统“龟裂纹”灰岩成因的新解释

本区“龟裂纹”大量发育于碳酸盐台地内的薄-厚层灰岩中,不受沉积环境、岩相和层位的严格控制。其在层面、侧面和底面上均呈不规则多边形。“龟裂纹”是含水的碳酸盐沉积物在构造应力和威岩作用中发生的裂开、脱水收缩,以后又经压溶作用使之改造并复杂化而成,因此“龟裂纹”灰岩是构造-成岩作用的产物。     

A note on the characters of some Lower Gondwana coals of West Siang district in the Arunachal Himalaya and their trace element content

Lower Gondwana coal from Garu-Gensi area in the West Siang district of Arunachal Pradesh in the Eastern Himalayas have been characterized with respect to their maceral constituents, mineral matter, ash composition, sulphurand trace-element contents. These are low-rank bituminous coals (V₀ = 0.64) and their vitrinite content is about 60%. A first hand data with respect to twenty one trace-elements are reported. Our data indicate that these Lower Gondwana coals of extra-peninsular region are richer in terms of their trace-element content when compared with their counter parts of peninsular India.     

华北地块北缘西段巴音诺尔公—狼山地区牙马图岩体的岩浆混合成因

华北地块北缘西段巴音诺尔公—狼山地区的牙马图岩体以二长花岗岩为主,岩体中广泛发育岩浆暗色包体,二者界线明显。包体为岩浆结构,大多数具有塑性外形,发育淬冷边、反向脉,存在多种不平衡结构和矿物组合,如斜长石环带、石英眼斑、针状磷灰石等,显示岩浆混合特征;包体的SiO2含量为48.40%～55.40%,寄主花岗岩SiO2含量为65.03%～72.85%,具有明显的SiO2含量间隔;与寄主花岗岩相比,包体的Fe、Mg、Ca、Ti含量较高;包体和寄主花岗岩的主要氧化物之间具有很好的线性关系,微量元素和稀土元素特征相似。包体和寄主花岗岩的这些地球化学特征显示出明显的岩浆混合趋势。岩相学和元素地球化学特征表明暗色包体是基性岩浆侵入到酸性岩浆淬冷的产物,牙马图岩体存在两种岩浆的混合作用。     

Modelling Discharge Rates and Ground Settlement Induced by Tunnel Excavation

Interception of aquifers by tunnel excavation results in water inflow and leads to drawdown of the water table which may induce ground settlement. In this work, analytical and numerical models are presented which specifically address these groundwater related processes in tunnel excavation. These developed models are compared and their performance as predictive tools is evaluated. Firstly, the water inflow in deep tunnels is treated. It is shown that introducing a reduction factor accounting for the effect of effective stress on hydrodynamic parameters avoids overestimation. This effect can be considered in numerical models using effective stress-dependent parameters. Then, quantification of ground settlement is addressed by a transient analytical solution. These solutions are then successfully applied to the data obtained during the excavation of the La Praz exploratory tunnel in the Western Alps (France), validating their usefulness as predictive tools.     

陕西汉中天坑群形成条件与分布规律

通过对陕西汉中天坑群岩溶地质遗迹的广泛调查和分析,确定了宁强禅家岩、南郑小南海、西乡骆家坝和镇巴三元四个天坑群集中分布区,从地层岩性、地貌、构造等方面总结了汉中天坑群形成地质条件和分布规律,研究认为二叠纪－三叠纪巨厚的碳酸盐岩地层为天坑（群）发育的物质基础,断裂、褶皱构造是天坑（群）形成的控制条件,特别是次级构造决定了天坑发育的具体位置,新构造抬升及湿热的气候为天坑的形成提供了岩溶动力。汉中天坑群水平上呈带状成群分布,垂向上差异较大,1 000~2 000 m居多的空间分布特征。岩溶天坑的形成经历了四个阶段的演化过程。      

Les minéraux techniques naturels : connaissance,typologie et propriétés d'usageNatural technical minerals: investigation,typology and utilisation properties

By nature minerals are heterogeneous materials for many of their properties. These properties also vary according to composition and structure fluctuations, compared to definitions. Technical minerals are used in applications where their performances depend on intrinsic properties and processing conditions. It is possible to base rankings on simple criteria, allowing estimating the abilities of minerals for each utilisation. The research of the corresponding mechanisms concerns the molecular level. These questions are discussed for kaolins, raw materials for baked clays, talqueous materials and montmorillonites. To cite this article: J. Yvon et al., C. R. Geoscience 334 (2002) 717–730.     

A Comprehensive Approach to the Observation and Prevention of Debris Flows in China

This paper presents a classification of debris flows in China. These are classified into four related types according to their formation factors, material components, fluid properties, and movement patterns. Details of field observations of debris flow in China are also given. Several ways of using the parameters of debris flow are listed as well as their applied results. Some equations are formulated using velocity, discharge, and impact force. In addition, the paper presents a comprehensive approach to the prevention of debris flows.     

Palaeo-mixing zone karst features from Palaeocene carbonates of north Spain: criteria for recognizing a potentially widespread but rarely documented diagenetic system

Marine-meteoric mixing zone dissolution effects are a major feature of present day karst systems in carbonate platforms, yet are rarely reported in the geological record. An example is described from the upper Danian platform limestones of the Alava province, in the western Pyrenees, north Spain. This consists of several narrow zones with sponge-like porosity analogous to the “Swiss-cheese” features found in present day mixing zones. These zones are stained by Fe-oxides and overlie limestones which are irregularly dolomitized and contain disseminated pyrite. These high-porosity zones are interpreted as having developed in marine mixing zones where mixing corrosion and microbially mediated processes increased dissolution. If collapsed, ancient mixing zones could be misinterpreted as “terra-rossa” palaeosols. The main criteria to identify them as mixing zone products are their occurrence below a palaeo-meteoric phreatic zone, their association with stratified oxic and anoxic redox zones and petrographic evidence for highly variable calcite saturation states.     

松辽盆地火山岩储层裂缝地质特征与地球物理识别

描述了松辽盆地营城组火山岩储层的储集空间类型及其在地球物理方法上的响应。钻井提示松辽盆地营城组火山岩储层的主要岩石类型有11种,主要储集空间为气孔、溶孔、砾间孔和裂缝。有效火山岩储层总孔隙度多为5%~10%,裂缝孔隙度通常仅0.2%~1%。裂缝的密度和开启程度是渗流性和产能主控因素,其密度和充填程度随岩性岩相变化而变化。在井区,微电阻率扫描成像测井成功识别出裂缝长度和密度,进而估算裂缝视孔隙度。在无井区,叠前裂缝检测方法可以半定量识别裂缝密度和方向。火山岩储层的测井-地震识别成果应用于庆深气田天然气开发井网部署和井下压裂方案,已经取得明显实效。     

First record of the family Scolebythidae (Hymenoptera) in mid-Cretaceous amber from Myanmar

Two new genera and species belonging to the family Scolebythidae are described from mid-Cretaceous amber of Myanmar, Cursoribythus silvestris and Siccibythus musculosus. These taxa are introduced into the current phylogenetic tree of the family, in order to analyze their relationships and observe their impacts on our understanding of the family. The implication of the findings (this is the first record of the family in the Cretaceous amber deposits of Myanmar) are discussed.     

临涣矿区底含水化学特征及其形成作用探讨

阐述了临涣矿区开采前、后新生界底部含水层的水化学特征及其形成作用;提出了底含水化学成因模式。对矿井底含突水水源的准确判断及井筒破裂原因分析具有积极意义。      

Morphotectonic analysis of alluvial fan dynamics: comparative study in spatio-temporal scale of Himalayan foothill,India

Alluvial fan is a depositional fluvial landform that is characterised by sediment flow and hydrological processes and is also controlled by tectonic activity. These extraordinary features have always attracted researchers since the past as they preserve the past records, but now, this study is focused on the formation meso-level fans with its spatio-temporal dynamic nature. These tributaries have formed secondary alluvial fans at their debouching points. The dynamics of the fans are controlled by the hydrological responses and tectonic base and also by the sedimentation processes. The origin of these tributaries and their respective fans are related to the last stage of Himalayan uplift. This is the region of Himalayan foreland basin which contains the main frontal thrust and makes the region tectonically very active. The region is drained by many large rivers and their numerous tributaries. The active tectonism, the configuration of the basin and also the deposition of the sediments carried by these rivers have formed alluvial fans where the channel debouches into the widened valley. In the present study, the meso-level alluvial fans formed by River Gish and the Rivers Neora and Murti have been studied. Both these fans are present in the piedmont region of the Himalayas, but they deliver different characteristics, and the nature of their deposition is also different. This is mainly because of the influence of the minor faults in the region which control the channel pattern and also have a great influence in the sediment delivery to the downstream section of the channels. Thus, in order to understand the influence of tectonics in the dynamics of these fans, some morphotectonic parameters have been taken into consideration. These include mountain front sinuosity index, valley floor width-to-depth ratio, and tectonic tilt. The calculated hypsometric integral also depicts that the two fans are at different stages of development.     

Development of world production and trade up to the year 2000 — A third world view

Conclusion The implications of this prospect for trade and international transportation are clear. If developing countries are to transform their economy and build up internal capacity for continued self-sustained growth, they will be able to do this only within certain restraints. These are likely to involve a certain decrease either in absolute or relative terms of their participation in world trade and their contribution to international transportation. Such a period of lessening trade will, however, be temporary and will last only whilst the economy is being transformed. Once this phase is passed, a new basis would have been laid for engaging in mutually beneficial international trade instead of the present one-sided exercise in self-flagellation.     

Investigations of clay colloid aggregates by scanning transmission X-ray microspectroscopy of suspensions

The environmental behaviour of colloidal clay in aquatic systems is linked to the properties of their aggregates. Earlier investigations of clay colloids were performed with electron microscope techniques which caused de-hydration of the particles. Information on the structure of colloid aggregates is needed for understanding their sedimentation behaviour, as well as colloid contaminant transport properties in natural systems. Scanning transmission X-ray microspectroscopy successfully produced images of montmorillonite colloid aggregates in a pseudo-equilibrium state in 1 mM NaCl suspensions equilibrated for more than a year. These clay aggregates were revealed at photon energies below the O absorption edges of clay and water. They were spherical or ellipsoidal with diameters of the order of 100–800 nm. The aggregates are porous and gel like with lower densities than the clay mineral. These investigations are important for modelling the occurrence of clay aggregates in aqueous environments.     

人为土的工程分类与利用研究

为了系统地了解和掌握人为土的工程性质,更好地开发和利用人为土,本文对人为土进行了比较系统的研究,定义了人为土的内涵,分析了人为土的成因,确立了人为土的分类原则,建立了人为土的工程分类和利用体系。根据人为土的成因,将人为土分成二个大类,五个亚类和十一个种类,并对每一类土的内涵、基本原理、工程性质及其优缺点等进行了详细的分述,在此基础上,提出了各类人为土的工程利用方案和适用范围。研究成果为人为土的研究和工程利用提供了理论基础。     

The terminology of structures in thrust belts

A review of structures and geometric relationships recognized in thrust belts is presented. A thrust is defined as any contractional fault, a corollary being that thrusts must cut up-section in their transport direction. ‘Flats’ are those portions of a thrust surface which were parallel to an arbitrary datum surface at the time of displacement and ‘ramps’ are those portions of thrusts which cut across datum surfaces. Ramps are classified on the basis of their orientation relative to the thrust transport direction and whether they are cut offs in the hangingwall or footwall of the thrust. Lateral variations in the form of staircase trajectories are joined by oblique or lateral ramps which have a component of strike-slip movement.An array of thrusts which diverge in their transport direction may form by either of two propagation models. These are termed ‘piggy-back’ propagation, which is foreland-directed, and ‘overstep’ propagation which is opposed to the thrust transport direction. An array of thrust surfaces is termed an ‘imbricate stack’ and should these surfaces anastamose upwards a ‘duplex’ will result; the fault-bounded blocks are termed ‘horses’. A duplex is bounded by a higher, ‘roof’ thrust and a lower, ‘floor’ thrust. The intersection of any two thrust planes is termed a ‘branch line’.Thrusts can be classified on the basis of their relationship to asymmetric fold limbs which they cut. A further classification arises from whether a particular thrust lies in the hangingwall or footwall of another one.The movement of thrust sheets over corrugated surfaces, or the local development of thrust structures beneath, will fold higher thrust sheets. These folds are termed ‘culminations’ and their limbs are termed ‘culmination walls’. Accommodation of this folding may require movement on surfaces within the hangingwall of the active thrust. These accommodation surfaces are termed ‘hangingwall detachments’ and they need not root down into the active thrust. This category of detachment includes dip-slip ‘hangingwall drop faults’ which are developed by differential uplift of duplex roofs, and ‘out-of-the-syncline’ thrusts which develop from overtightened fold hinges. Back thrusts, as well as forming as hangingwall detachments, may also form due to layer-parallel shortening above a sticking thrust or by rotation of the hangingwall above a ramp.