川东地区锶矿床地质特征及成因探讨

川东是我国锶矿资源远景最大，质量最佳的成矿区。铝矿产于下三叠统嘉陵江组二、四段的灰岩－白云岩－天青石膏质藻层纹白云岩－石膏岩（或灰岩）韵律层中。天青石膏质藻层纹白云岩是含矿层。准同生阶段已有天青石沉积，局部富集形成矿源层。在后生阶段的热力、压力驱动下．四川盆地的热卤水（２２０～３００℃）沿含矿层交代形成条纹条带状天青石矿层；第二期热卤水（１５０～２２０℃）在含矿层及其附近的碳酸盐岩裂隙中充填交代，形成四块状、脉状天青石；第三期热卤水（＜１５０℃）沿断裂充填形成天青石、重晶石脉。一、二期热卤水成矿作用常相互叠加，形成工业矿床。川东褶皱带西部背料部位具良好的找矿前景。     

重庆地区天青石型锶矿床成矿特征

重庆地区的锶矿产于下三叠统嘉陵江组二、四段的灰岩－白云岩－天青石膏质藻层白云岩－石膏岩韵律层中。天青石膏质藻层白云岩是含矿层。准同生阶段已有天青石沉积,形成矿源层。在后生阶段的热力、压力驱动下,第一期热卤水（２２０￣３００℃）沿含矿层交代形成条纹条带状天青石矿层;第二期热卤水（１５０￣２２０℃）在含矿层及其附近的碳酸盐岩裂隙中充填交代,形成团块状、脉状天青石;第三期热卤水（〈１５０℃）沿断裂充填形     

青阳县百丈岩钨钼矿床中斑岩型(浸染状)钼矿体的发现及其找矿意义

青阳县百丈岩鸽钼矿床中斑岩型（浸染状）钼矿体发育在层控夕卡岩型鸽钼矿含矿层位之下的花岗岩中。岩体与夕卡岩型钨钼矿的底板呈侵入接触关系,接触界面与岩层面呈小角度相交,岩体在平面上呈舌状分布。发现的斑岩型（浸染状）钼矿体厚度大,对扩大矿床规模具有重要意义,并可为今后皖南地区钼矿找矿提供新的思路。     

贵州瓮福磷矿床大塘矿段稀土元素地球化学特征

大塘矿段位于贵州瓮福磷矿白岩矿区,矿体（层）赋存于震旦系陡山沱组（Pt₃³d）,根据成矿的先后时间,该矿段形成了a矿层（下矿层）、b矿层（上矿层）2个矿层,矿层中间为一白云岩G夹层,是典型的海相沉积碳酸盐岩型磷矿床。为深入研究该矿段磷矿床的稀土元素地球化学特征,文章通过野外地质调查、光学显微镜观察、X射线荧光光谱（XRF）与等离子体质谱（ICP-MS）、扫描电镜与能谱（SEM-EDS）等实验方法对其进行了较系统的分析。研究结果表明,a、b矿层磷矿石的δCe、δEu呈负异常,b矿层较a矿层负异常值更明显,且Y/Ho比值由a矿层到b矿层逐渐升高,同时结合Ce_anom-Nd关系图,均反映出由a矿层到b矿层的形成环境是由相对还原环境转变为相对氧化环境。b矿层稀土元素PAAS标准化模式曲线较为一致,为中稀土元素略富集的帽状形态,反映磷矿形成过程中明显有生物或有机质参与;b矿层形成过程中经历了较强的水动力搬运,沉积速率较高,沉积时间较短,其ΣREY较a矿层低。大塘矿段a、b两个矿层磷矿石中Y等大部分稀土元素都主要以类质同象形式赋存于胶磷矿中。     

PAM-KC1-石灰乳泥浆治理钻孔坍塌

为确保松散粉状矿层取心和有效的捞取裂隙、溶洞中泥砂状充填物，我们加工了一种双活瓣钻头（见附图）     

浙江玲珑膨润土矿床地质特征及成因机理浅析

玲珑膨润土矿床产于晚侏罗世劳村及黄尖组沉积期的断陷火山盆地内。矿区共见膨润土矿层（体）９个，主要呈层状、似层状或顺层透镜状产出，具层控特点，个别为严格受断裂控制的脉状体。矿石呈土状、砂状等，主要蚀变矿物为蒙脱石，少量伊利石，具改型特点，浅部钙基土，至０ｍ标高左右（当地地面标高４５ｍ左右）改型为钠基土。矿石在应用方向上具某一领域的单向性。各矿层在合矿岩系、成矿母岩及蒙脱石蚀变程度等方面存在较大差异，经分析认为：该矿床属一较典型的以后期表生成矿作用为主的复成因矿床。     

沂源县龙泉寒武纪石膏矿地质特征

沂源龙泉石膏矿是近几年山东省内勘查评价的几处寒武纪一奥陶纪海相碳酸盐岩系型石膏矿之一，这类矿床的发现及勘查评价，为省内石膏矿资源勘查与开发规划部署提供了新线索。沂源县龙泉石膏矿产于寒武纪长清群朱砂洞组丁家庄段，自下而上分3个矿层，呈不规则的层状、似层状，以第I矿层规模最大；最大厚度13．98m。矿石自然类型以块状、网脉状—块状石膏为主，其次为网脉状—浸染状石膏、硬石膏和纤维状石膏。沂源龙泉石膏矿含矿层位及矿层分布比较稳定，矿床规模较大。     

山东省泰安市大汶口盆地岩盐矿地质特征及开发意义

大汶口盆地岩盐矿均为第四系所覆盖,钻孔揭露,除第四系外,主要为古近系官庄群大汶口组。大汶口盆地主要是由南留断裂所控制。岩盐矿是大汶口盆地盐类矿床的主体,矿层多而集中,厚度大而变化小,品位高而稳定。矿层延展面积约45km3,其平面形态为一个椭圆形,在空间上整个含盐段似一个向北缓倾的大透镜体。矿石自然类型有3种,即块状岩盐（灰白盐）、含杂质岩盐（杂色盐）和脉状岩盐,其中以块状岩盐为主,含杂质岩盐次之,脉状岩盐不具有工业意义。该矿床地质条件好、埋藏深度适宜,外部建设条件好,该矿床具备大规模开发的条件,矿业开发可促进当地的经济发展.当地政府有关部门已在着手工作,推动该岩盐矿规模开发进程。     

津巴布韦大岩墙南段两翼铬铁矿床特征及成因探讨

津巴布韦大岩墙蕴含丰富的铬铁矿资源，不同部位成矿特征存在差异。钙碱性铁质基性-超基性岩浆结晶分异过程中伴随着铬铁矿的成矿作用，南部岩浆房两翼300 m深度范围内共赋存7个不连续的铬铁矿层，矿层垂向间距30~50 m，南部矿层发育优于北部；铬铁矿层厚度多为0.2~1 m，铬铁矿层发育于辉橄岩系和辉石岩系的接触部位，三者呈渐变式过渡接触，共同构成典型的韵律结构；两翼矿层产状呈对称状倾向于岩墙的轴部，倾角约为10°~20°；矿石多为自形-半自形微细粒结构，稀疏浸染状及中等浸染状构造，矿石为需选贫铬矿石，w（Cr₂O₃）=5%~30%，且矿体内Pt+Pd含量可观。大岩墙南段两翼铬铁矿为典型的早期岩浆结晶分异矿床，后期构造运动加剧了矿层的不连续性，并对局部岩矿层产状产生改造，蛇纹石化蚀变形成了指示矿体的标志性斑杂构造岩。     

四川省宁南县跑马铅锌矿成因浅析

跑马铅锌矿为产于下寒武统麦地坪白云岩中的层控矿床，主要受层间破碎带控制，有两个含矿层，多呈层状产出。麦地坪段在沉积过程中铅、锌相对富集形成源层，经后期热液叠加改造富集成矿，为沉积改造型似层状（不规则状）铅锌矿床。     

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.     

Report of the restudy of the defined global stratotype of the base of the Silurian System

The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.     

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″.     

The Tendencies of the Development of the Mineral-Resources Sector at the Turn of the Century

Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base.     

Causes of the famine among the rural population of the Sahelian zone of the Sudan

Taking the example of W Sudan, an analysis of the climatic incidents leading to the two recent famine disasters is made. On this natural background, the human side is investigated. Focus is directed towards the fragile economic structure of the famine-prone population groups. An early-warning system for famine in the Sahelian Zone is proposed taking grain production and storage, livestock development and the relationship between the prices of livestock and grain as major indicators.     

东濮凹陷北部沙河街组三段中亚段沉积环境分析

东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。     

郯庐断裂南段研究进展与断裂性质讨论

据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。     

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.