北京平原区土壤氡地球化学特征分析

对北京平原区北西向和北东向两条氡浓度剖面进行了测量,发现北部地区氡背景值要大于南部,东向西方向氡浓度变化起伏频繁。分析其原因主要是受到土壤母质、地层以及断裂的影响,发现断裂是影响北京平原区氡浓度高值的主要因素。     

上海罗店-周浦隐伏断裂第四纪活动性综合探测与研究

罗店-周浦断裂是纵贯上海市中心城区重要的北西向隐伏活动断裂,其第四纪活动性对城市地质安全至关重要。通过高精度重力勘探、浅层地震勘探及可控源大地音频电磁测深勘探等地球物理方法,结合钻探联井剖面及光释光年代学测定,对罗店-周浦断裂在区域内的展布特征及第四纪活动性进行了探测与研究。结果表明,该断裂在上海市南部区域仍具有较好的延展性,断裂行迹在重力剖面、可控源音频大地电磁测深剖面及浅层人工地震剖面上都有较好的反映。重力面积测量结果显示该断裂在上海市南部呈现为一组近平行断层行迹;浅层人工地震勘探与钻孔地层联合剖面揭露断层最浅上断点埋深相似（约为200 m）,可控源大地音频电磁测深反映断裂深部特征明显。物探剖面及钻孔联合剖面综合显示,断裂并未明显错断上覆中更新统上部地层,结合光释光年代学标定,认为该断裂最新活动时代为早更新世。罗店-周浦断裂与区内历史地震事件关系密切,目前区域地应力环境为北西向压应力状态,该断裂易于发生张扭性活动,其活动性特征及地震危险性特征需要持续关注。      

准噶尔北缘卡拉先格尔断裂带深部结构的MT探测

卡拉先格尔断裂是1931年8月富蕴8级大地震的发震断裂,也是阿尔泰造山带重要的多期活动断裂和阿尔泰地区晚古生代火山盆地向东延伸的限制性断裂。通过在卡拉先格尔地区5条大地电磁测深剖面测量与资料分析,获得了关于沿剖面的地壳二维电性结构。结果显示卡拉先格尔断裂在深部表现为向南西陡倾的低阻异常带。卡拉先格尔断裂地表走向与磁异常梯度带走向一致,呈北北西向展布。新的结果还发现在卡拉先格尔断裂西南侧存在一条北西走向北东倾向的次级断裂。结合卡拉先格尔断裂地表变形特征,指出该断裂不仅是走滑断裂、还是斜滑断裂,其正断活动可能造成卡拉先格尔断裂带东侧地质体的隆升与剥蚀,从而造成断裂带两侧地质体剥蚀程度与成矿特征的差异。     

电阻率层析成像技术在琼东北活动断裂探测中的应用

琼东北1605年琼山地震发震的中心区域东寨港东侧发育多组近东西向和北西向的活动断裂,且均为隐伏断裂。为探明断裂的分布位置及其活动性,现采用电阻率层析成像技术将其中琼山-铺前断裂(F8)以及F7、F6、F5共四条,北西走向断裂作为此次探测目标断裂。结合前人水文钻孔资料和断裂分布,在珠溪河北岸和罗豆农场北侧部署了三条电法探测线,结果表明区域沉积地层在三条反演剖面上均可以划分出三层视电阻率梯度带,与钻孔资料对应较好。同样,视电阻率对已知四条活动断裂均有明显特征的低阻异常反映,除断裂F7的倾向解释存在争议外,其余三条断裂解释均得到钻孔验证。     

关于河西走廊盆地榆木山北缘断裂晚第四纪活动特征的新认识

榆木山北缘活动断裂属于河西走廊中段盆地内的次级隆起——榆木山隆起北侧断裂系的组成部分,它位于榆木山北缘断裂北侧山前,是与榆木山隆起有成生联系、活动时间很新的现代活动断裂。榆木山北缘活动断裂呈向北北东略微凸出的弧形,走向总体为北西向,倾向南西,自南东向北西走向由北西向渐变为北西西向,甚至近东西向,倾角自中等—低角度,东段较陡。榆木山北缘断裂的活动性质在剖面上表现为以南西盘向上逆冲为主,水平位移不明显,特别是中段的石炭口—窑儿沟口一带,在向南缓倾的主逆冲上盘往往发育反向逆冲断层,并导致上更新统砂砾层发生牵引褶皱。该断裂在距今13.1～13.3ka之间和距今3～5ka期间发生过2次明显的新构造活动。     

白乃庙金矿床控矿构造解析

白乃调金矿区的节理包括东西向剖面共轭剪切节理,北东－北西向平面共轭剪切节理,北北东向剖面共轭剪切节理。与之相应的断层有近东西向逆断层,北东向和北西向的平移断导以及北北东向的斜冲断层。此外,北东向断层的低序次构造亦呈北北东走向,但其性质为平移断层。东西向、北东和北西向断裂形成于南北向挤压构造应力场。它们控制了主要含金石英脉展布。其中,２６号主矿脉就位于北东向平移双断裂－白乃庙断裂的北北东向低序次平移     

藏南马扎拉金锑矿床电性结构特征与地质解译

通过马扎拉金锑矿床0线勘探线上电阻率联合剖面测量和音频大地电磁测深两种电法手段的对比分析,表明矿区东南部构造交汇区域的0线勘探线剖面电性特征呈南北高中间低、浅部低深部高、深部电阻率比浅部异常大的特征。结合已有地质调查成果综合分析,在该剖面上解译出可能的岩体2处,可能的北倾断裂5条,并大致估算了这些地质体的规模。矿区东南部近东西向断裂与北西向断裂、近南北向断裂交汇处为有利的找矿位置,而0线剖面上一系列近东西向北倾断裂的找矿潜力值得进一步评估和验证。     

深圳北西向断裂分布特征及其活动性研究

深圳地区断裂以北东向五华-深圳断裂带和北西向珠江口断裂带多条次级断裂相互切错的断裂空间分布特征为主,同时多组东西向断裂穿插其间组成复杂的"棋盘格子状"断裂系统。北东向和北西向断裂是现今活动的发震构造,自有地震记录以来在深圳市及其周边发生的多起微震事件表明北西向和北东向断裂活动仍在持续,尤其是近百年来珠江口断裂带发生的多起中强震更是佐证了这一观点。针对深圳南山区及周边北西向断裂的第四纪活动性研究,从露头区实地断层追索、断层特征的考察以及已有钻孔和地球物理资料收集等方法入手分析总结了深圳地区北西向主要断裂的分布特征和活动性:深圳地区北西向断裂在空间上控制了珠江口断陷,区域上切割北东向断裂,空间分布连续性较差;北西向断裂最新活动于晚、中更新世,部分断裂表现为老断裂新活动,最新活动时间存在明显分段特征。全新世以来活动性明显减弱,部分次级断裂属于弱活动或不活动断裂。      

苏南东部及上海地区的北西向断层

笔者对苏南东部及上海地区的北西向断层作了系统的野外观察,并对断裂带内构造岩作了详细地研究;对北西向断层的力学性质、构造地质特征及地质意义作了初步探讨。现介绍如下,如有不当,敬请指正。一、北西向断层的野外观察 (一)太湖大东岛,石炭系灰岩中发育了三条北西向压性断裂(图1、2),间隔40～50m。其中断层A走向北30°西,倾向北东,倾角75°;断裂带宽度为7m。断层B走向北35°西,倾向南西,倾角70°;断裂带宽度为8m。断裂C走向北35°西,断面近直立;断裂     

金湖凹陷隐性断裂带形成机制及分布

金湖凹陷基底存在北东、北西向两组断裂。北西向基底断裂活动较弱,对盖层变形影响较小,在盖层中多以隐性断裂带显现;北东向基底断裂活动强烈,对凹陷盖层变形影响较大,不仅形成了凹陷东部边界杨村断裂在内的多条显性断裂,而且形成了多条隐性断裂带。凹陷中部的北东向石港显性断裂带将凹陷分割成西部斜坡带和东部凹陷带。东部凹陷带受基底北西向断裂隐性活动的影响呈现南北分段特征。凹陷盖层中还发育了大量近东西走向的三、四级正断层,它们大致平行成带分布,形成了宝应平行雁列式断裂构造带、唐港雁列式断裂构造带、卞闵杨平行雁列式断裂构造带、西斜坡平行入字型断裂构造带、汊涧泥沛平行雁列式断裂构造带等一系列油气富集区带。上述构造带中的油气藏分布明显受到北东和北西向基底断裂活动影响,呈现北东、北西或近南北向成带、成串分布特征。应用区域地质、重磁等资料开展隐性断裂带预测,识别出10条北东向、5条北西向、6条南北向隐性断裂带。沉积盖层中形成的这些隐性断裂带控制了储集砂体分布、改善了储层物性、使隐性圈闭成带成串分布,是油气聚集成藏的有利区带。     

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.     

Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth

It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T ₃ = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.     

Global repeating events in the history of the Earth and the motion of the Sun in the Galaxy

Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.     

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。     

某高速公路下伏煤矿采空区稳定性分析

在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。      

摩擦桩基桩土间极限摩阻力取值问题探讨

通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。     

The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads

In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.     

On the consistency of proposed models for the Pyrenees with the structure of the eastern parts of the belt

The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time.