大兴安岭北段巴升河岩体锆石U-Pb年代学及其地质意义

大兴安岭北段扎兰屯地区巴升河岩体由碱长花岗岩组成.采用LA-ICP-MS方法对碱长花岗岩开展锆石U-Pb测年,结果为297.8±3.6 Ma,岩体形成于早二叠世.该岩体4个样品的全岩地球化学等特征显示：巴升河岩体中碱长花岗岩具有富Si、高K、富碱的特征,属于弱过铝质钾玄岩系列,同时,样品∑REE偏高,Eu负异常明显,富集大离子亲石元素,具有A型花岗岩特征,综合前人研究成果及同位素年代学特征,认为兴安地块与松嫩地块拼合的时间早于298 Ma.     

大兴安岭北段巴升河岩体锆石U-Pb年代学及其地质意义

大兴安岭北段扎兰屯地区巴升河岩体由碱长花岗岩组成.采用LA-ICP-MS方法对碱长花岗岩开展锆石U-Pb测年，结果为297.8±3.6 Ma，岩体形成于早二叠世.该岩体4个样品的全岩地球化学等特征显示：巴升河岩体中碱长花岗岩具有富Si、高K、富碱的特征，属于弱过铝质钾玄岩系列，同时，样品∑REE偏高，Eu负异常明显，富集大离子亲石元素，具有A型花岗岩特征，综合前人研究成果及同位素年代学特征，认为兴安地块与松嫩地块拼合的时间早于298 Ma.     

华南桂东南地区加里东期Ⅰ型花岗岩类的岩石成因及构造意义

龙新岩体和夏郢岩体位于扬子地块与华夏地块拼合带的西南端,岩体中的Ⅰ型花岗岩成因研究对揭示桂东南地区早古生代的地球动力学背景及其构造演化具有重要的地质意义.对龙新岩体的寄主岩和其暗色微粒包体,以及夏郢岩体岩石进行了LA-ICP-MS锆石U-Pb定年、Lu-Hf同位素和全岩地球化学研究.锆石U-Pb定年结果显示,龙新岩体的寄主岩（花岗闪长岩）的年龄为440±2 Ma;龙新岩体的暗色包体（闪长岩）的年龄为441±1 Ma,寄主岩与暗色包体为同期岩浆作用的产物.夏郢岩体花岗闪长岩和二长花岗岩年龄分别为447±3 Ma和436±3 Ma,说明夏郢岩体至少发生了2期岩浆侵入事件.Hf同位素研究表明,龙新岩体寄主岩和暗色微粒包体的锆石ε_Hf（t）值分别为-3.32~-5.83和-17.89~-1.82,二阶段模式年龄（T_DM2）分别为1.62~1.76 Ga和1.57~2.54 Ga;夏郢岩体早期花岗岩闪长岩和晚期二长花岗岩的锆石ε_Hf（t）值分别为-15.43~3.03和-4.79~6.82,T_DM2分别为1.59~1.99 Ga和0.97~1.70 Ga,指示物源主要来自古-中元古代的地壳物质.地球化学特征表明龙新岩体寄主岩为准铝质高钾钙碱性Ⅰ型花岗岩,寄主岩和暗色微粒包体均富集轻稀土元素和大离子亲石元素,亏损重稀土元素及高场强元素;夏郢岩体早期的花岗闪长岩为弱过铝质高钾钙碱性Ⅰ型花岗岩,晚期的二长花岗岩则为强过铝质高钾钙碱性Ⅰ型花岗岩,主微量元素特征均与龙新岩体寄主岩相似.根据研究区花岗岩和镁铁质包体的岩相学、年代学、地球化学及Hf同位素组成特征,表明龙新岩体的暗色包体（闪长岩）为岩浆混合成因,而龙新岩体寄主岩（花岗闪长岩）和夏郢岩体（早期花岗岩闪长岩和晚期二长花岗岩）具有一致的岩石源区和岩石成因,但在后期的成岩过程中存在岩浆混合和结晶分异程度的差异.综合以往对华南地区构造背景的研究,认为龙新和夏郢岩体是在扬子地块和华夏地块陆内造山期后,岩石圈伸展减薄,热的幔源岩浆上涌底侵,中-下地壳受到地幔热影响发生部分熔融,形成的酸性岩浆在源区和基性岩浆经历了不均一且不强烈的壳-幔混合作用形成的.      

西天山吐拉苏岩体中花岗岩的年代学和地球化学特征及其地质意义

吐拉苏岩体位于西天山吐拉苏盆地的东北缘,由石英闪长玢岩、辉石闪长玢岩和花岗岩组成,其中花岗岩主要为花岗闪长玢岩和花岗斑岩.它们表现出高硅、高铝、富碱的特征,里特曼指数（σ）=1.61~3.18,A/CNK=1.00~1.09,A/NK=1.07~1.68,为准铝质-弱过铝质高钾钙碱性花岗岩;相对富集Rb、Th、U等大离子亲石元素,明显亏损Nb、Ta、Sr、P、Ti等元素;轻重稀土分馏明显,（La/Yb）_N=7.48~12.12、中等Eu负异常（δEu=0.47~0.62）,无Ce异常.但花岗斑岩较花岗闪长玢岩碱含量更高,更加接近准铝质钾玄岩系列,Sr、P、Ti等元素的亏损程度更强,且轻稀土更富集,可能说明花岗斑岩中壳源物质含量增加.锆石LA-ICP-MS U-Pb定年研究获得花岗斑岩的侵位年龄为305.9±5.9 Ma.锆石Hf同位素组成显示,ε_Hf（t）值介于0.4~8.7,表明花岗岩的岩浆源区有幔源物质的加入;T_DM2值介于766~1 294 Ma,表明岩浆源区为中元古代-新元古代新生地壳.综合吐拉苏岩体中两类花岗岩的地质、地球化学特征、年代学和区域地质背景,认为从花岗闪长玢岩到花岗斑岩结晶分异增强、壳源物质的贡献增大,花岗岩形成于后碰撞环境,岩浆源区为中元古代-新元古代新生地壳,但有不同比例幔源物质的加入.      

西秦岭碌础坝岩体的锆石U-Pb年龄、成因及其地质意义

碌础坝岩体位于秦岭构造带的西段,自内向外依次由含电气石黑云二长花岗岩、含斑细粒黑云母二长花岗岩、似斑状黑云母二长花岗岩、中粗粒黑云母二长花岗岩和中粒黑云母石英闪长岩组成,岩体中普遍发育岩浆暗色包体。LA-ICPMS锆石U-Pb定年显示,碌础坝岩体形成于早中生代,其岩浆演化可划分为中三叠世（235Ma）和晚三叠世（218～209Ma）两期。早期为中粒黑云母石英闪长岩,该期岩石SiO2含量较低,富碱,属于准铝质、高钾钙碱性系列,具有I型花岗岩的特征;晚期为黑云母二长花岗岩,具有高硅、富碱的特征,属于准铝质-弱过铝质、钾玄岩-高钾钙碱性I型花岗岩。从早到晚,岩石的稀土元素总量具有由高到低的变化趋势,两期岩石的稀土元素配分曲线均为轻稀土相对富集的右倾型,晚期黑云母二长花岗岩更亏损HREE,早期闪长岩负铕异常不明显,晚期花岗岩的负铕异常较为显著。两期岩石均富集K、Rb、Ba等大离子亲石元素,而相对亏损P、Nb、Ta、Ti等高场强元素。岩体中发育的岩浆暗色包体与寄主岩石的主要氧化物具有相关性,微量和稀土元素特征相似。岩体中黑云母二长花岗岩和中粒黑云母石英闪长岩的εNd(t)值分别为-8.0和-7.0,相应的tDM为1.43Ga和1.40Ga。早期中粒黑云母石英闪长岩的εHf(t)为-4.47～0.53,集中于-3～-1之间,tDMC主要为1.6～1.3Ga;晚期黑云母二长花岗岩的εHf(t)变化于-11.64～1.16,集中于-7～-2范围内,tDMC为1.7～1.4Ga。岩石地球化学和Nd-Hf同位素组成特征表明,碌础坝岩体的源区物质是以中元古代壳源物质为主,有年轻幔源组分的参与。该岩体与其北边的中川岩体在年代学、岩石地球化学和同位素组成上具有一定的相似性,因此,从岩浆作用角度考虑,该岩体的外围也可能与中川岩体的一样,具有金的成矿潜力。     

额尔古纳地块北东部二十一站岩体花岗岩类岩石成因与构造环境

二十一站岩体位于中亚造山带东段额尔古纳地块北东部上黑龙江盆地Cu-Au成矿带内,经过多年勘查研究,岩体中已发现斑岩型铜金矿化,但由于未进行系统工作,在物质来源和岩浆演化方面尚未取得重大突破。本研究对二十一站岩体系统采样,进行锆石U-Pb年代学、岩石地球化学、Sr-Nd-Pb同位素研究。结果显示,二十一站岩体岩浆活动大致分2个阶段,花岗岩、石英正长岩和二长花岗岩形成于186.5～206.9Ma,属于晚三叠世–早侏罗世;石英二长斑岩和石英二长岩形成于127.6～133.2 Ma,属于早白垩世。岩体2个阶段花岗岩类岩浆岩主要为高钾钙碱性系列–钾玄岩系列,为Ⅰ型花岗岩。微量元素方面,样品富集大离子亲石元素(Rb、Th、K、Pb等), Pb具有明显正异常,亏损高场强元素(Nb、Ta、Ti、P等),表现出弧岩浆或主动大陆边缘岩浆的特征。稀土元素方面,样品表现为轻稀土元素富集,重稀土元素亏损的平滑右倾型分配模式,具有轻微的Eu负异常(0.62～0.90), LREE/HREE值为9.48～14.81,(La/Yb)_N值为11.57～23.22,轻、重稀土元素分馏明显,表明岩浆经...     

辽东半岛丹东地区中生代花岗岩锆石U-Pb年龄、Hf同位素特征及其地质意义

为了确定辽东半岛丹东地区中生代花岗岩岩石类型、成岩时代及其形成构造背景.选取三股流岩体、五龙背岩体和丁岐山岩体开展岩相学、锆石LA-ICP-MS U-Pb年代学、岩石地球化学和锆石Hf同位素地球化学研究.结果表明:三股流岩体由花岗闪长岩、似斑状黑云母二长花岗岩和中粗粒黑云母二长花岗岩组成,后两者成岩年龄分别为137.2±1.2 Ma和123.2±1.3 Ma;丁岐山岩体由中细粒碱长花岗岩、石英正长岩和石英二长岩组成,获得中细粒碱长花岗岩成岩年龄为121.1±1.5 Ma;五龙背岩体由中粗粒二长花岗岩组成,成岩年龄为146.8±0.8 Ma.元素和同位素地球化学特征表明,三股流岩体的花岗闪长岩为钾玄岩系列,似斑状黑云母二长花岗岩和中粗粒黑云母二长花岗岩以及五龙背岩体和丁岐山岩体均为高钾钙碱性,3个岩体不同岩石类型的A/CNK均小于1.1,为I型花岗岩;岩体均富集轻稀土元素和大离子亲石元素,亏损重稀土元素和高场强元素,具Eu负异常;ε_Hf（t）值为-22.40~-9.77,两阶段Hf模式年龄T_DM2为2 999~1 915 Ma,揭示三股流岩体、五龙背岩体和丁岐山岩体可能是古元古代古老地壳部分熔融形成.结合区域构造演化认为三股流岩体、五龙背岩体和丁岐山岩体均形成于活动大陆边缘,五龙背岩体形成于古太平洋板块向欧亚板块的俯冲挤压的构造背景,三股流岩体和丁岐山岩体形成于古太平洋板块向欧亚板块的俯冲后的伸展环境.      

锆石U-Pb年代学和地球化学对浙皖马鞍山高分异岩体成因的约束

为了解由早期(伟晶、巨晶)斑状二长花岗岩、中期(细粒)花岗岩和晚期花岗(斑)岩脉组成的马鞍山杂岩体的成因, 采用SHRIMP和LA-ICP-MS锆石U-Pb法厘定其侵入时代, 年龄显示伟晶斑状二长花岗岩为132.2±1.6 Ma, 巨晶斑状二长花岗岩为127. 7±1.2 Ma, 细粒花岗岩为128.3±1.1 Ma, 花岗斑岩脉为127.4±1.8 Ma.岩石地球化学研究结果表明岩体从早到晚具有从钾玄岩系列向高钾钙碱系列演变特征, 分异演化程度逐渐变高; 斑状二长花岗岩具有高REE含量, 轻重稀土分异较为明显, 具较强负铕异常和弱右倾的配分曲线特征, 富集K、Th、U、Rb等元素, 弱亏损Ba、Sr、P、Nb、Ta、Ti等元素; 细粒花岗岩及花岗(斑)岩脉具有较低REE含量, 轻重稀土分异不明显, 具强负铕异常和"V"型配分曲线特征, 富集K、Th、U、Rb等元素, 强亏损Ba、Sr、P、Nb、Ti等元素.马鞍山岩体为浙西北-皖南地区早白垩世俯冲造山后陆内拉张作用环境下下地壳部分熔融的同源岩浆侵位结晶分异作用形成的产物, 具有高分异I型花岗岩的特征.      

湖南香花岭复式碱长花岗岩体侵入期次关系的识别

香花岭碱长花岗岩为一复式岩体。不同期次侵入体之间的接触关系、白色和绿色含铍条纹岩以及磁铁矿条纹岩与不同期次侵入体之间的对应关系、通天庙、塘官铺、太平和新风不同矿化组合与不同期次侵入体之间的成因联系以及遥感图像中的环形构造特点和差异明显的Rb-Sr同位素等时年龄表明该岩体是两期四次碱长花岗质岩浆侵入作用的产物,燕山早期的三次岩浆侵入与本区矿化关系密切;而燕山晚期的一次岩浆侵入与矿化无关。上述认识可对矿区的某些地质问题作出合理的解释。     

刘家坪杂岩体的岩石特征及时代

刘家坪杂岩体出露于扬子准地台西北边缘。该区扬子期岩浆活动,早期为刘家坪组海底喷发的中～酸性火山岩系,晚期先后侵入有角闪辉长岩—石英闪长岩—斜长花岗岩—辉绿岩脉。岩浆岩具有幔源岩浆及造山带地区火山岩的特征。据震旦系覆于刘家坪杂岩体之上,其底部砂砾岩的砾石中有杂岩体成分,以及杂岩体侵入于同位素年龄值为6.43亿年的刘家坪组之中,认为刘家坪杂岩体时代为前震旦纪。     

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.     

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.     

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″.     

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。     

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。     

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。      

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.