东昆仑石头坑德镍矿床岩石矿物特征

青海石头坑德是近年来发现的镍矿床,赋矿岩石为辉长岩、辉石岩相和橄榄岩相;矿石金属矿物主要为磁黄铁矿、镍黄铁矿、黄铜矿、黄铁矿、磁铁矿。矿石主要为交代粒状结构,海绵陨铁状,块状构造。该文中对石头坑德镍矿床和夏日哈木超大型镍矿的主要岩石矿物组合和矿石矿物组合作了比较,表明石头坑德镍矿具有形成大型-超大型规模矿床的有利条件。     

东昆仑石头坑德镍矿床岩石矿物特征

青海石头坑德是近年来发现的镍矿床,赋矿岩石为辉长岩、辉石岩相和橄榄岩相;矿石金属矿物主要为磁黄铁矿、镍黄铁矿、黄铜矿、黄铁矿、磁铁矿。矿石主要为交代粒状结构,海绵陨铁状,块状构造。该文中对石头坑德镍矿床和夏日哈木超大型镍矿的主要岩石矿物组合和矿石矿物组合作了比较,表明石头坑德镍矿具有形成大型-超大型规模矿床的有利条件。     

山东桃科铜镍矿床矿物学特征及其对矿床成因的指示

桃科铜镍矿床是山东目前发现的仅有的2处铜镍矿床之一,也是中国最早开采的铜镍矿床之一,同时也可能是中国形成时代最老的铜镍矿床。含矿岩体主要由橄榄辉长苏长岩、蚀变辉长苏长岩、变辉长岩、角闪岩组成,主要矿物为贵橄榄石、古铜辉石、普通辉石、角闪石和中基性斜长石(培长石、中长石、拉长石),岩石常发生强烈的绿泥石化、钠黝帘石化、纤闪石化;矿石中黄铜矿+镍黄铁矿+磁黄铁矿的矿物组合,为典型的岩浆型铜镍硫化物矿床的矿物组合;岩石及矿物特征表明矿床为岩浆作用的产物。通过矿物显微结构特征以及计算得出:桃科岩体橄榄石开始结晶温度大约在1421℃左右,古铜辉石和普通辉石的结晶温度在1030~1230℃之间,两矿物相在岩石中可以共存。矿石中大量镍黄铁矿蚀变为针镍矿,黄铜矿在边部蚀变为斑铜矿,以及黄铁矿较高的Co/Ni比值(0.1~12.9,平均4.1),都表明矿床在后期遭受了强烈的热液叠加改造作用。     

新疆萨尔托海铬铁矿中的Fe-Ni-As-S矿物研究

新疆萨尔托海铬铁矿是一个典型的与蛇绿岩有关的高铝型豆荚状铬铁矿,其中矿石铬尖晶石发生了明显的热液蚀变,发育了富Cr的蚀变环边,形成高铁铬铁矿,Cr#在蚀变后升高,发生了Cr元素的次生富集。在矿石颗粒间隙中的Fe-Ni-As-S矿物组合主要为镍黄铁矿-赫硫镍矿-针镍矿-砷镍矿。围岩纯橄岩普遍发育强烈的蛇纹石化,其中的Fe-Ni-As-S矿物组合为赫硫镍矿-镍黄铁矿-砷镍矿,还有少量的针镍矿和铜矿物。通过对硫化物的成分对比分析,认为矿石中的镍黄铁矿和赫硫镍矿都属于岩浆演化的产物(600℃),与赫硫镍矿和针镍矿一样,均从贫S的母岩浆中通过岩浆熔离过程形成。围岩和矿石中的含砷矿物以及围岩中的镍黄铁矿都是晚期热液活动的结果,其中砷镍矿具有特殊的蠕虫状-乳滴状结构,与围岩中的赫硫镍矿和镍黄铁矿共生。围岩和矿石中Fe-Ni-As-S矿物组合的形态和成分差异,说明金属矿物的整体演化从岩浆期到热液期经历了从贫S到富As的环境变化,最终形成了现在所观察到的复杂Fe-Ni-As-S矿物组合。     

芬兰北部克维特斯塔镍-铜-铂族元素矿床地质特征及矿床成因

位于芬兰北部中拉普兰绿岩带的克维特斯塔(Kevitsa)镍-铜-铂族元素矿床是世界上主要的岩浆镍-铜硫化物矿床之一。该矿床储量大,含丰富的镍-铜硫化物和铂族元素。对矿床产出环境、地质特征、矿床成因等进行了总结,结果表明:矿体主要赋存于克维特斯塔基性—超基性层状侵入体的超基性单元中。主要矿石类型为普通型和镍-铂族元素型2种,其中镍-铂族元素型矿石内橄榄石具极高的Ni含量。主要矿石矿物为磁黄铁矿、镍黄铁矿、黄铜矿、黄铁矿、针硫镍矿、红砷镍矿、砷镍矿、辉砷镍矿等,绝大部分铂族矿物包含在硅酸盐中和附着在硫化物颗粒边界。Re-Os、Sm-Nd、Sr及S同位素特征显示成矿岩浆为幔源,但受到地壳物质的混染作用。Pb同位素年代学结果表明克维特斯塔侵入体形成于古元古代。     

陕西略阳煎茶岭镍矿床成矿及矿石变质过程的地球化学研究

矿床中存在着岩浆离熔成因的磁黄铁矿-镍黄铁矿矿石和热液改造成因的黄铁矿-针镍矿-辉镍矿矿石。研究证明现在矿石中存在的硫化物均为较低温度条件下的变质产物,并且矿物组合的更替不仅同温度变化有关,同时还受体系中氧逸度和硫离子活度的控制。矿物组合的地球化学分析表明,现有Fe-Ni-S体系低温（<300℃）相平衡图解之间存在着矛盾的原因可能是忽略了氧化-还原条件的影响。     

东天山主要铜镍矿床中磁黄铁矿的矿物标型特征及其成矿意义

东天山是中国最重要的岩浆铜镍硫化物矿带之一,产有黄山东、黄山、香山、葫芦等大中型铜镍矿床。图拉尔根、白石泉两处镍铜矿床为近年来在新疆地区铜镍找矿中的重大发现,两者均属于与镁铁质-超镁铁质杂岩有关的岩浆熔离-贯入型矿床。矿物共生组合以磁黄铁矿 镍黄铁矿 黄铜矿为特征,磁黄铁矿系矿石中最主要组成部分。文章以X射线衍射、扫描电镜、电子探针分析并辅以常规显微镜,查明这些矿床中磁黄铁矿均系Co、Ni的最主要载体矿物,Co、Ni元素主要以游离状态的硫化物(或硫砷化物)形式存在,如镍辉砷钴矿、钴辉砷镍矿、镍黄铁矿及紫硫镍矿等矿物。它们多以微细包裹体或出溶体形式随机地分布于磁黄铁矿内部,而少量的Co、Ni元素则以类质同像方式存在于磁黄铁矿晶格之中。图拉尔根、白石泉、葫芦三矿床中磁黄铁矿在多型结构以及微量元素地球化学方面均表现出一定的差异,系由两矿床容矿岩石基性程度及成矿温度之差异引起。     

高镍铜镍矿床的特征、形成机制与勘查展望

岩浆铜镍矿床100%硫化物中的Ni含量与赋矿岩石和成矿过程紧密相关,记录岩浆成分、分异程度与硫化物演化过程。硫化物异常高镍(高镍硫化物)往往被认为与科马提质岩浆或者后期热液作用密切相关。近年研究结合勘查证实,赋含高镍硫化物的矿床(高镍铜镍矿床)不仅限于科马提岩,还与苦橄质、玄武质岩浆有关,另外,热液富集作用并不是必要因素。本文总结了世界上高镍铜镍矿床的基本特征和形成机制,分析提出了不同机制的判别标志,并展望了其勘查前景。详细对比高镍铜镍矿床的产出环境、赋矿岩相、矿石特征、矿物组合等特征,该类矿床往往产于大陆裂谷和造山带环境,与基性程度较高的岩浆有关,以橄榄岩赋矿为主,含镍硫化物组合主要为镍黄铁矿-磁黄铁矿-黄铜矿组合,少数为针镍矿-镍黄铁矿-黄铁矿组合。科马提岩相关矿床可将Ni含量大于16%的硫化物定义为高镍硫化物,苦橄质-玄武质岩浆相关矿床的硫化物可分为高镍硫化物(Ni10%)、中镍硫化物(5%～10%)和富铜硫化物(Ni5%,CuNi)。原生高镍硫化物可由富镍岩浆熔离、硫化物从橄榄石中吸取Ni、硫化物结晶分异、硫化物与硫不饱和岩浆反应等机制形成。苦橄质-玄武质岩浆相关的矿床,硫化物与橄榄石的Fe-Ni交换反应是高镍硫化物形成的重要机制。辉石岩源区地幔部分熔融形成富镍岩浆是否为高镍硫化物形成的必要条件尚存争议。不同机制形成的高镍硫化物具有迥异的岩石-矿物组合和地化特征。硫化物矿物组合、橄榄石成分(Fo值、Ni含量、Fo值-Ni含量的相关性)、伴生元素(铜、铂族元素)丰度-配分模式等特征可作为区分不同高镍硫化物形成机制的有效指标。我国新疆黄山南、坡一和青海夏日哈木矿床(部分浸染状矿化橄榄岩)以赋含高镍硫化物为特征,新疆喀拉通克矿床的硫化物则以富铜为特征,中国其余矿床的硫化物均属中镍硫化物。目前研究指示中国的高镍铜镍矿床与母岩浆相对富镍、硫化物与橄榄石Fe-Ni交换作用密切相关,后者可使硫化物Ni含量提升3%～5%。在铜镍矿床勘查方面,稀疏-中等浸染状高镍硫化物矿石即可达到工业品位,稠密浸染状-块状高镍硫化物矿石可达到很高的Ni品位(10%),是高品位镍矿勘查的一个重要方向。造山带环境富水、相对高氧逸度(可高达QFM+1)的岩浆可能是形成高镍硫化物的有利条件,该环境橄榄石Fo值较高(87mol%)的岩体有利于形成高镍硫化物。     

喷流沉积型多金属矿床中镍钼的赋存特征

喷流沉积型矿床是矿床地质学研究的前沿课题,查明矿石中重要组分(镍和钼)的赋存状态是该类矿床地质学研究的重要内容。湘黔地区天鹅山-黄家湾、大坪-大浒镍钼矿带是典型的海底喷流沉积矿床,本文采集该矿区的样品,应用化学和光谱定量分析、偏光显微镜和X射线衍射、扫描电镜、电子探针等大型现代仪器相结合的分析手段,研究了矿石中镍和钼的赋存状态。化学和光谱分析确定矿石中镍含量为3.76％,钼含量为4.99％;偏光显微镜下观察发现金属矿物零星分布,颗粒细小,结晶程度差,光学特征极不明显,晶体形貌特征难以观察,初步推断矿石矿物以胶状形式存在,但在光学显微镜下很难为这些矿物定名和描述;X射线衍射分析验证了偏光显微镜鉴定结果,印证了样品中存在很多非晶质矿物,仅有钨钼钙矿和镍黄铁矿两种矿物含有镍钼,且矿物含量很低(分别为0.4%和0.8%),对比化学分析结果,可推断样品还存在其他富含镍钼元素的矿物。进一步对富集镍钼元素的区域进行电子探针分析,最终确定了镍除了赋存于辉砷镍矿、方硫镍矿中,在胶状黄铁矿和磁黄铁矿边缘呈蠕虫状花边的镍黄铁矿中也有富集;钼主要赋存于碳硫钼矿中。矿石中的镍钼主要赋存于由胶态向结晶态过渡的金属矿物中,研究成果为该类矿床的矿石矿物学研究、选矿、冶炼及矿石综合利用提供重要的信息和依据。     

岩浆熔离型铜镍矿床硫同位素地球化学特征研究

我国岩浆熔离型铜镍矿床主要分布在大陆边缘裂谷、造山带和峨眉山大火成岩石中,矿床赋存岩体中下部;矿石呈星点状、浸染状、海绵陨铁状和块状,主要矿物为磁黄铁矿、镍黄铁矿、黄铜矿、磁铁矿、橄榄石、石英等;矿床形成温度较高;成矿氧逸度范围受磁黄铁矿-黄铁矿-磁铁矿和橄榄石-石英-磁铁矿矿物组合控制。硫化物硫同位素显示出两种特征,一种为金川、赤柏松、喀拉通克、黄山东、红旗岭、金宝山等矿床,硫化物的硫同位素主要分布在-1.6‰~+3.1‰;另一种为煎茶岭、力马河矿床,硫化物的硫同位素组成为+1.5‰~13.8‰。根据硫同位素组成特征可以得出大多数岩浆熔离型铜镍矿床硫化物的硫主要来自岩浆(金川、赤柏松、喀拉通克、黄山东、红旗岭、金宝山),少数矿床硫的来源较为复杂(煎茶岭和力马河),很可能是两种以上来源。     

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.