大别山北麓钼矿找矿重大进展及其矿床地质特征研究

在总结近年来钼矿勘查成果的基础上,综合论述了大别山钼矿床的基本特征和成矿规律.钼矿带呈北西向狭长带状展布,钼矿床的形成与燕山期中酸性浅成-超浅成小花岗岩斑岩体有关,钼矿床直接产于岩体内外接触带及其附近;矿床类型主要为斑岩型,少量矽卡岩型、热液脉型.结合Re-Os同位素精测年龄数据,确定了大别山钼矿床的成矿时代主要集中在...     

云南石屏县法乌铅锌矿地质特征及成因

石屏法乌铅锌矿矿体呈似层状、脉状、透镜状产出,矿体的近矿围岩均为峨山花岗岩体之二长花岗岩,成矿与花岗岩的侵入有着密切的联系。矿区KT5与KT9两个主矿体在成因上有明显不同,KT5矿体产于构造破碎带中,受断裂构造控制约明显,为与花岗岩有关的中低温热液充填型脉状铅锌矿床。KT9矿体产于花岗岩体与碳酸盐岩接触带的矽卡岩中,受花岗岩与碳酸盐岩接触带控制,为接触交代矽卡岩型铅锌矿床。     

青海卡而却卡铜多金属矿床蚀变矿化类型及矽卡岩矿物学特征

卡而却卡铜多金属矿床是柴达木盆地南缘西段祁漫塔格地区颇具特色的一个破碎蚀变带热液脉状-矽卡岩型矿床。矿区内可见2类围岩蚀变：矽卡岩化和黄铁绢英岩化。前者由印支期似斑状黑云母二长花岗岩侵位引起,在岩体侵入接触面及外接触带围岩的不同岩性界面、构造破碎薄弱带形成含铜多金属矽卡岩透镜体,由透辉石、钙铁辉石、钙铁（铝）榴石、符山石、硅灰石、方柱石和阳起石等一套十分典型的钙矽卡岩矿物组成;后者在矿区西北部的似斑状黑云母二长花岗岩体中形成多条呈NWW向平行展布的黄铜矿化热液蚀变带,构成断裂破碎带控制的细（网）脉浸染状热液脉型矿化。研究认为：卡而却卡铜多金属矿床的形成与印支期侵位、具有浅成和高侵位特点的似斑状黑云母二长花岗岩关系密切,产出的矽卡岩型铜多金属矿与破碎蚀变带控制的细（网）脉浸染状热液脉型铜矿的成岩成矿年龄基本一致,其构造-岩浆活动背景相同,但属不同阶段、不同深度和不同部位发生成矿作用的产物,形成以接触带（或外接触带）矽卡岩型铜多金属矿为主体的、成矿母岩体内的构造断裂发育部位伴有热液脉状铜矿化的复合型矿床。     

大东山锡矿田矿床地质特征及矿床成因

大东山锡矿田矿化类型复杂,其中矽卡岩型锡矿规模大,可分含锡矽卡岩型和硫化物矽卡岩型。岩体区有脉状和面状云英岩产出,前者多具锡矿化,后者具钨矿化。燕山第四期花岗岩是锡(钨)成矿母岩,含SiO274.96%~75.28%,K2O+Na2O7.37%~8.54%,K2O>Na2O,与南岭地区钨锡成矿岩体具有相似的岩石化学特征。锡矿成因类型可划分为接触交代型、侵入岩浆热液型和风化矿床。根据成矿地质条件,认为在接触带寻找硫化物矽卡岩、硫化物型锡矿有较大前景,而在岩体区具有寻找云英岩型钨矿的潜力。     

内蒙古苏尼特左旗乌日尼图钨钼矿床地质特征及找矿标志

乌日尼图钨钼矿床是近年来在国土资源大调查中发现的一个大型矿床.钨钼矿体主要产于燕山期细粒花岗岩与中下奥陶统乌宾敖包组砂板岩的外接触带中,矿体多呈脉状及透镜状,且明显受构造裂隙控制;矿床成矿在不同部位其矿化形式不同.在成矿母岩--燕山期细粒花岗岩中形成浸染状矿石;同时在与含钙质的板岩接触部位形成夕卡岩型矿石,在乌宾敖包组裂隙中形成热液脉型矿石.其中热液上侵与围岩接触处的细脉状矿床最为主要;矿体围岩蚀变发育,硅化、黄铁矿化与矿化关系最为密切;矿床深部钨钼矿石呈浸染状分布于细粒花岗岩中,后者为成矿母岩;矿床成因属广义的斑岩型矿床.     

安徽省当涂县九连山铁矿地质特征与找矿标志

多年来在宁芜地区发现了大量的玢岩型铁矿床。九连山铁矿位于和睦山铁矿与钟山铁矿之间,铁矿体主要产于三叠系黄马青组粉砂岩与闪长岩体的接触带,以及黄马青组的层间破碎带;矿区共有10个铁矿体,矿体呈似层状、透镜状,大部分为磁铁矿体,少量的赤铁矿体,矿石多为块状构造和浸染状构造。研究认为,九连山深部成矿的闪长岩体与和睦山的成矿岩体为同一岩体,九连山铁矿可作为和睦山式铁矿埋深较大的矿床实例,矿床类型属于玢岩铁矿中的接触交代型+热液充填型铁矿床。文章还对九连山铁矿的找矿标志进行了归纳。     

青海江里沟钨多金属矿成矿控制因素及矿化富集规律

青海江里沟钨多金属矿床目前是青海境内规模最大的钨矿床,其规模达中-大型,大地构造位置属秦祁昆复合造山系秦岭造山带西段。本文从江里沟钨多金属矿床的成矿地质背景、矿区地质特征、矿体特征等方面入手,总结矿床控矿因素及矿化富集规律。矿体受岗察复式花岗岩体与围岩接触带控制,矿化围绕岩体具有明显的分带性,自岩体向外形成了斑岩型钼矿化-云英岩型钨矿-矽卡岩型钨铜钼矿-角岩型钨矿-脉状铅锌矿的矿化系列,以矽卡岩型为主要类型。其矿床成因为与晚三叠世江里沟复式花岗岩体晚阶段花岗斑岩和细粒花岗岩的侵入及岩浆后期热液有关的多位一体矿床,为下一步的找矿提供依据。     

福建周宁咸格钼矿地质特征及找矿潜力分析

咸格钼矿床产于燕山早期二长花岗岩岩体与晚侏罗世南园组第二段流纹质晶屑凝灰岩的内接触带。矿体呈似层状、脉状,受断裂构造和岩体层间节理控制。属高中温热液交代充填型矿床。     

西藏阿浪扎玛铜钨矿床地质特征及控矿因素

阿浪扎玛铜钨矿床属矽卡岩型矿床,主要成矿岩体为燕山晚期黑云母二长花岗岩。铜钨矿体赋存于花岗岩体与中侏罗统马里组灰岩接触带矽卡岩中。     

滇西北衙金多金属矿床成矿作用特征标志

文章通过对北衙金多金属矿床成矿作用特征标志的系统总结,认为从岩体内部到外接触带,矿化样式以"脉-块体-层-脉"的内外多元结构模式产出:岩体内部Au-Fe(Cu)矿体呈透镜状脉、平行脉沿断层破碎带陡倾斜产出;岩体接触带附近的矽卡岩带围绕岩体呈环状分布,Au-Fe-Cu矿体以大透镜状、块体状在矽卡岩带中断续产出;外带Au-Fe、Pb-Ag矿体呈似层状、透镜状,沿层间破碎带产出;远程带Au-Fe矿体呈小透镜状脉、平行脉沿断层破碎带陡倾斜产出。矿体对应的矿物组合、成矿元素和蚀变分带具有自高温到低温的分布规律和矽卡岩型矿床的特征。矿床的热液成矿作用阶段可划分为早矽卡岩、晚矽卡岩、磁铁矿、石英硫化物以及碳酸盐五个热液阶段,各阶段流体包裹体划分为富液相包裹体、富气相包裹体、含子晶矿物包裹体、富含CO_2三相包裹体等四类。成矿年龄为36.46 Ma—39.44 Ma,与石英正长斑岩的成岩年龄35.00 Ma—36.72 Ma基本一致。矿床成矿深度范围为0.7~2.2km。矿床类型为斑岩-矽卡岩型金多金属矿床。北衙组碳酸盐岩(T_2b)+多期断裂构造系统(接触带构造、岩性界面及层间破碎带、断裂裂隙、不整合面构造)+喜马拉雅期富碱斑岩侵位构成了"三位一体"的成矿系统和成矿模式。     

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。     

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.     

Paleomagnetic implications on the evolution of the tethys belt from the atlantic ocean to the pamirs since the triassic

We first re-examined the apparent polar wander curves for stable Eurasia and Africa since the Triassic. These curves were then combined together with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given. Then, most of the paleomagnetic results from the Tethys mobile belt, from the Atlantic to the Pamirs, were analysed.Several groups of plates, microplates and blocks can be seen. First, relatively stable regions like Maghreb and Sicily, which have not moved much. Then we have a group formed by Iberia, Sardinia, Italy and, to a lesser extent, Corsica and the Western and Central Alps. For these blocks, movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of Africa, but they are sometimes stronger.To the east, a major change takes place. The north of the Aegean Sea and the Ionian zone are clockwise rotated and these rotations are recent: Oligocene-Miocene for the first part, Pliocene to the present for the second part.A major problem arises in Turkey, Caucasus and Iran. Paleomagnetic results indicate a position far to the south of Eurasia, and, at the same time, geological evidence is in favour of a position close to Eurasia. We discuss these discrepancies.