西藏南部江孜地区白垩系的厘定

文中对藏南江孜地区深海一次深海白垩纪地层层序、系统及厚度进行了厘定。建组剖面甲不热、维美等构造复杂,地层层序变化大,重复多。厘定后的岩石层单元有加不拉组、床得组和宗卓组。加不拉组是一套以黑色页岩为主的地层,跨不白垩统一上白垩统三冬阶,下分黑层段和白层段;床得组由紫红色页片状泥灰岩组成,各坎潘期早－中期;宗且即著名的“北家混杂堆积岩”,页岩中含大量外来岩块,时代为坎潘期晚期和马斯特里赫特期。白垩系厚     

藏南江孜地区白垩系海相红层中红色页岩的颜色成因

白垩系大洋红层(Cretaceous Oceanic Red Beds,CORBs)在我国西藏江孜地区广泛发育,以床得组最为典型.本文以床得组红色页岩为研究对象,通过电子探针背散射电子像观察和成分定量分析、主量元素分析、X射线衍射分析,结合CBD(Citrate Bicarbonate Dithionite)提取铁氧化物前后漫反射光谱分析,认为床得组红色页岩中的铁氧化物只有赤铁矿,没有其它铁氧化物,赤铁矿是唯一的致色铁氧化物.电子探针背散射电子图像显示,赤铁矿分为结晶好和结晶差的两种形态.CBD提取前后反射光谱红度的变化,指示结晶差的赤铁矿的致色作用要远大于结晶好的赤铁矿,主要是细分散状、结晶差的赤铁矿造成了床得组红色页岩的红色.赤铁矿是同沉积一成岩早期阶段的产物,赤铁矿形成所需的铁来源于陆源输入.     

白垩纪大洋红层的致色机制及成因研究

为了查明白垩纪大洋红层的致色矿物及其赋存状态,并探讨白垩纪大洋红层可能的制约因素及成因模式,本文以中国西藏床得剖面红色页岩、意大利Vispi Quarry剖面红色灰岩以及北大西洋ODP1049C孔12X岩芯段Aptian-Albian期高频旋回红色泥灰岩为研究对象,对各剖面(或岩芯)中的红色和非红色样品分别进行了X射线衍射和漫反射光谱测试,同时对配制的含赤铁矿的标样进行了同样的测试。测试结果表明,无论是红色页岩、红色灰岩,还是红色泥灰岩,赤铁矿都是主要的致色矿物,其中西藏床得剖面红色页岩由结晶较好的碎屑状赤铁矿和结晶较差的细分散状的赤铁矿共同致色。在意大利Vispi Quarry剖面红色泥岩中,结晶程度相近的赤铁矿是唯一的致色铁氧化物,而在ODP1049C孔红色泥灰岩中,结晶差的赤铁矿和针铁矿的出现是泥灰岩呈红色的矿物学根源。赤铁矿的形成主要受铁的来源、沉积时的氧化还原条件以及成岩作用的影响,这些因素也成为制约红层形成的关键因素。本课题组在多年研究的基础上,结合前人研究成果进一步从矿物学的角度深化了大洋红层的成因模式。     

藏南江孜县床得剖面侏罗-白垩纪地层层序及地层划分

重测西藏南部江孜床得剖面后发现地层层序与前人认识完全相反,不只含上白垩统,还包括中—上侏罗统和整个白垩系;重新厘定了宗卓组、加不拉组,新建床得组,它们分属晚坎潘期—马斯特里赫特期、贝里阿斯期—三冬期和早—中坎潘期;由下向上可识别出６套沉积组合：安山岩层、黄层、黑层、白层、红层及滑塌层,大致对应于下热组（Ｊ２ｘ ）、维美组（Ｊ３ｗ ）、加不拉组（Ｋ（１－ ２）ｊ,床得浦段＋ 机布里段）、床得组（Ｋ２ｃ）、宗卓组（Ｋ２ｚｎ）     

峡东地区埃迪卡拉系黑色页岩的微量元素和Fe同位素特征及其古环境意义

通过分析宜昌峡东地区九龙湾剖面埃迪卡拉系陡山沱组黑色页岩的微量元素和Fe同位素组成,对埃迪卡拉纪海洋的氧化还原状态进行了制约。黑色页岩氧化还原敏感元素的富集系数以及U/Th、V/(V+Ni)、V/Cr值等在陡山沱期存在着明显的演化趋势。这些趋势显示陡山沱组二段下部水体处于氧化的状态,陡山沱组二段上部水体处于还原状态,陡山沱组四段黑色页岩发育在氧化环境中。同时,陡山沱组二段下部黑色页岩富集重的Fe同位素,表明黑色页岩来自于海水的铁主要是以Fe3+的氧化物或氢氧化物形式沉淀的,进一步说明这个时期的水体处于氧化状态。综合黑色页岩微量元素和Fe同位素信息,显示在埃迪卡拉纪陡山沱早期海水经历了先氧化后还原的过程,陡山沱晚期海水变得氧化了。这种特征与埃迪卡拉纪陡山沱期生物群的出现和演化相对应,说明海洋的氧化为埃迪卡拉纪生物的出现和演化提供了前提条件。     

西藏江孜-浪卡子一带的侏罗-白垩纪界线地层

侏罗系/白垩系界线是显生宙所有系级界线中存在问题最多的一个。西藏南部出露有良好的侏罗-白垩纪地层,本次工作在喜马拉雅地层区的康马隆子地层分区开展了海相侏罗系/白垩系的界线研究。江孜地区的界线地层被划分为维美组和甲不拉组;浪卡子地区的甲不拉组之下发育一套含大量火山岩层的火山－沉积地层,被称为桑秀组。该地层分区的地层系统由下至上为：维美组浅灰色厚层状粗-细粒石英砂岩;桑秀组黑色页岩、安山岩和玄武岩;以及甲不拉组黑色页岩、硅质泥页岩夹砂岩和砂质灰岩。维美组中含化石稀少,仅在江孜地区发现零星菊石Haplophylloceras、Himalayites等。桑秀组下部页岩和粉砂岩中找到少量菊石化石,属于Spiticeras、Berriasella、Haplophylloceras的一些种,和富集成层的双壳类Inoceramus everesti等。江孜甲不拉组下部化石丰富,划分为Spiticeras-Berriasella下组合和Himalayaites-Haplophylloceras上组合。本研究区的生物地层可与聂拉木地区的菊石化石组合对比。通过生物地层学对比,江孜-浪卡子地区的维美组时代为晚侏罗世Tithonian期,江孜地区甲不拉组下部和浪卡子地区的桑秀组均属于下白垩统。桑秀组下部的页岩段与江孜甲不拉组的最下部地层相当,上部火山岩的同位素年龄为133 Ma。据此,桑秀组的时代为Berriasian至Hauterivian期,侏罗系/白垩系的界线位于该组之底,以Virgatosphinctes、Aulocosphinctes的消失和Spiticeras的出现为标志。侏罗纪末期西藏特提斯海区普遍形成大规模海退,表现为维美组和门卡墩组顶部砂岩的同期沉积。     

康滇古陆西侧志留系龙马溪组红—黑转换特征 ——以宁蒗大槽子剖面为例

中上扬子区康滇古陆以东的志留系龙马溪组无"红层"发育,但在康滇古陆西侧的盐源—丽江地区,龙马溪组底部却发育有"红层"(为厚约2 m的紫红色硅质泥页岩)。为了明确该套"红层"的成因及地质意义,以盐源—丽江地区的宁蒗大槽子剖面为例,从岩性、岩相及岩石地球化学等方面,对龙马溪组下部"红层"到上部"黑层"的红—黑转换特征进行了研究。结果表明:①龙马溪组下部"红层"中含Fe~(3+),且无有机碳存在,推测这是"红层"致红的原因;②"红层"与"黑层"中稀土元素特征相似,但微量元素特征差异较大,尤其是"红层"中Co的含量均值高出"黑层"9倍以上,而"黑层"中Mo的含量均值高出"红层"9倍以上;③龙马溪组下部"红层"至上部"黑层",整体上是从相对富氧的氧化沉积环境转变为相对缺氧的还原沉积环境,也是沉积水体逐渐由浅变深的过程,这是红-黑转换的主控因素;④龙马溪组从下部"红层"转换至上部"黑层",其间构造背景均为活动大陆边缘环境,不同于康滇古陆以东的稳定大陆边缘背景。     

几内亚共和国博凯558铝土矿区赋矿岩石特征

几内亚共和国博凯558铝土矿为一处超大型风化残积三水铝石型铝土矿床。赋矿岩系的矿物组分呈上部富集三水铝石、赤铁矿;下部富集石英、白（水）云母、高岭石等。赋矿岩系的化学组分呈上部富集Al2O3、Fe2O3等,下部富集SiO2等。矿体赋存于赋矿岩系的上部铁矾土、铁红土内。     

沉积物中铁氧化物的定量方法及其 在白垩纪大洋红层中的应用

赤铁矿和针铁矿是自然界中最稳定的两种铁氧化物,广泛存在于地球的各个圈层。很多沉积物的颜色都是由它们引 起的,它们的形成和保存具有重要的环境指示意义。实验室中赤铁矿和针铁矿的表征和鉴定手段很多,但受其含量低、结 晶差、颗粒细小难分离等因素的困扰以及某些测试方法自身的限制,能用于铁氧化物定量分析的方法很少。文中就常用的 基于X射线衍射（XRD） 和漫反射光谱（DRS） 的铁氧化物定量方法进行了系统评价。在定性分析的基础上,采用基于 XRD的K值法获得西藏床得剖面红色页岩中赤铁矿的含量为3.81％~8.11％,采用DRS与多元线性回归相结合的方法获得北 大西洋ODP1049C孔12X岩芯段棕色层中赤铁矿和针铁矿的含量分别为0.13％~0.82％和0.22%~0.81％,橙色层中赤铁矿和 针铁矿的含量分别为0.19%~0.46％和0.29%~0.67％。与其它分析结果的比较表明,这两种定量方法在白垩纪大洋红层中的 应用是可行的。但在实际应用时,首先要通过XRD和DRS相结合来提高定性分析的准确性,然后通过综合分析铁氧化物的 预判含量范围和结晶程度来选择合适的定量方法。     

藏南白垩系黑-红层沉积岩有机质组成分布特征

对藏南江孜县床得剖面白垩系黑层和红层沉积岩进行的有机地球化学研究表明,黑层有机碳含量高于红层5～10倍,红层和黑层饱和烃主峰碳数分别为nC25和nC23;黑层和红层沉积有机质的母质来源都以水生植物和菌藻类等低等生物为主,陆源有机质的输入非常有限;但饱和烃的分布和主峰碳数的差异可能反映了有机母源物质在种群方面的差异,而这种差异可能主要是水体温度存在差异造成的,即红层发育时期水体温度可能高于黑层沉积时期.而在高温度条件下,水生生物和陆生植物的生长发育受到限制,造成原始有机质产率和有机质沉积保存量低可能是红层沉积岩形成的主要原因.     

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。     

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.     

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。     

塘口水电站坝基岩体透水性和渗漏问题分析

塘口水电站大坝基础座落在断层和裂隙较发育的龟裂纹灰岩上,岩体完整性差、透水性强,多年运行后,大坝灌浆廊道和排水廊道出现多处集中性漏水,为确保大坝安全和电站正常发电,根据渗漏性质和成因,采用对灌浆廊道补充帷幕灌浆,对排水廊道进行固结+帷幕+回填灌浆。通过灌浆处理后,效果良好,表明灌浆工程有效的将导致坝基渗漏的上下游的裂隙通道封闭,并顺利的经受了随后的汛期洪水考验,大坝安全得到保障。     

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.     

Calculation of the Inverse of the Covariance

In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix.     

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。      

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.