大陆岩石圈对扩张机制的响应—辽蒙地质走廊中—新生代火山活动的时空分布

选择辽西为中心,以近东西向延伸800km的辽蒙地质走廊为研究区,通过年代学研究,确认130Ma以来的中、新生代火山活动对称分布的时空格局,具有“中间老、两侧新”的特点,而且随着时间的推移,软流圈来源的岩浆向东西两侧侧向流动,岩浆来源不断加深。在此基础上提出“软流圈底辟体上涌和水平侧向流动”的模式。     

大陆岩石圈对扩张机制的响应——辽蒙地质走廊中—新生代火山活动的时空分布

选择以辽西为中心,近东西向延伸800km的辽蒙地质走廊为研究区,通过年代学研究,确认130Ma以来的中、新生代火山活动对称分布的时空格局具有“中间老、两侧新”的特点,而且随着时间的推移,软流圈来源的岩浆向东西两侧侧向流动,岩浆来源不断加深。在此基础上提出“软流圈底辟体上涌和水平侧向流动”的模式。     

对中国东部中生代动力学机制的新认识

从20世纪70年代板块构造学说引入中国后,中国地质学家(包括笔者)普遍接受了太平洋板块向欧亚板块俯冲导致中国东部中生代强烈的构造-岩浆活动和相应的成矿作用的观点,乃至成为被认知的理论至今仍然广泛流传。但是,2000—2006年国土资源部开展的《中国岩石圈三维结构》专项研究成果表明:深部软流圈(层)物质上涌才是中国东部中—新生代强烈构造-岩浆活动的主要动力来源。在进一步研究中国东部巨厚的软流圈形成的原因时发现:中侏罗世以来,中国大陆受到了来自4个不同方向的动力挤压,由此导致软流圈物质汇聚到中国东部及邻区大陆之下。太平洋板块的俯冲力只是4个方向中的一个——由东向西挤压,它起到了阻挡软流圈物质继续向东部"洋区"流动的作用,可称它为"远程力效应"。     

华北早白垩世末岩石圈局部被扰动的时空证据

对比研究了辽西阜新碱锅和内蒙古平庄含地幔捕虏体的阜新组玄武岩与碱锅义县组的安山岩，并结合前人的同位素年代学研究，确认在早白垩世117—106Ma期间，该区火山岩岩浆来源从富集的岩石圈地幔转变成亏损的软流圈地幔．即岩浆作用从以壳幔相互作用为主转化成软流圈的底辟体上升。将岩浆来源的巨大变化与前人关于古地磁和白垩纪超静磁带的研究成果以及研究区脊椎动物群集群死亡事件联系起来，认为这是一次重要的岩石圈圈层结构被扰动的事件。通过区域对比，发现阜新、平庄岩浆源区从富集地幔向亏损地幔转化的事件同样存在于山东沂水以及松辽盆地。而且岩浆来源转化的时间大体一致，均发生在100～80Ma前后。根据前人提供的小比例尺的三维面波速度结构，推断中国东部软流圈物质沿着构造薄弱带上涌，使岩石圈发生局部扰动的起始时问可能是晚中生代100Ma，由于各地构造差异它们可以表现为若干软流圈上涌的底辟体。     

青藏高原新生代两类超钾质岩石的成因——实验岩石学和地球化学约束

青藏高原分布有羌塘—囊谦—滇西和冈底斯两条新生代钾质-超钾质火山岩带。羌塘—囊谦—滇西超钾质岩浆活动的峰值时间为40～30Ma,主体岩石具有Ⅰ型超钾质岩的高MgO和低CaO、Al2O3含量特征;30～24Ma期间羌塘中、西部出现Ⅲ型钾质-超钾质岩浆活动,主体岩石以贫SiO2、高CaO、Al2O3和低MgO/CaO为特征。冈底斯新生代超钾质火山岩也显示I型超钾质岩的高MgO和低CaO、Al2O3含量特征,其形成时间为25～12Ma。综合超钾质岩石的实验资料,可知区内I型超钾质岩的源区以富硅、富钾流(熔)体交代形成的金云母方辉橄榄岩为主;Ⅲ型钾质-超钾质岩浆源区则以斜辉橄榄岩地幔为主。囊谦—滇西Ⅰ型超钾质岩带空间上严格受红河走滑构造带所控制,40～28Ma出现I型超钾质岩浆活动,16Ma转变为OIB型钾质火山岩。岩浆源区从岩石圈地幔向软流圈演变,暗示大型走滑断裂引起的岩石圈地幔减薄和软流圈上涌是导致交代岩石圈地幔金云母分解熔融产生区内I型超钾质岩浆的主控因素。羌塘中部35～34Ma有软流圈来源为主的钠质碱性玄武岩岩浆的喷发,30～24Ma转变为以岩石圈地幔为主要来源的Ⅲ型钾质-超钾质岩浆活动,岩浆源区从软流圈向岩石圈迁移,指示软流圈上涌伴随的富CO2流(熔)体活动是导致古交代岩石圈地幔升温熔融产生Ⅲ型钾质-超钾质岩浆的主控因素,软流圈上涌可能是俯冲板片断离或岩石圈地幔拆沉作用的结果。     

地壳运动的机制及动力来源

通过分析各种地壳运动假说，提出了地幔胀缩力和重力是地壳运动的主要动力来源，地球自转离心力和潮汐摩擦力是地壳运动的次要动力来源。地幔软流圈中放射性元素衰变热产生的膨胀使岩石圈产生拉裂，软流圈物质以岩浆形式喷出地表，岩浆柱散热收缩，产生负压，岩石圈在负压和重力作用下形成地壳运动。     

全球超大型斑岩铜矿浅析

燕山-喜马拉雅期构造运动,引起印度板块与欧亚板块剧烈碰撞、太平洋板块向东俯冲与美洲大陆向西漂移,产生了"加厚旋涌"效应,即下地壳的加厚并深插上地幔软流圈,改变了软流圈运动方式而上涌,伴随强烈的岩浆活动和成矿物质上涌,完成了大规模成矿作用,在特提斯-喜马拉雅地区和太平洋东部边缘产出世界级超大型斑岩铜矿系列.初步提出太平洋东部边缘成矿作用明显超过特提斯-喜马拉雅地区原因.     

全球超大型斑岩铜矿浅析

燕山-喜马拉雅期构造运动，引起印度板块与欧亚板块剧烈碰撞、太平洋板块向东俯冲与美洲大陆向西漂移，产生了"加厚旋涌"效应，即下地壳的加厚并深插上地幔软流圈，改变了软流圈运动方式而上涌，伴随强烈的岩浆活动和成矿物质上涌，完成了大规模成矿作用，在特提斯-喜马拉雅地区和太平洋东部边缘产出世界级超大型斑岩铜矿系列.初步提出太平洋东部边缘成矿作用明显超过特提斯-喜马拉雅地区原因.     

内蒙古阿巴嘎旗地区新生代玄武岩基本特征及成因

内蒙古阿巴嘎旗及其以北地区新生代玄武岩是更新世中心式火山活动产生的大陆溢流玄武岩,该区玄武岩以高碱、富钛、贫铝为特征,属于钠质碱性玄武岩系列.源区是软流圈上地幔,玄武岩是部分熔融和分离结晶两种作用的结果.地幔橄榄岩部分熔融产生玄武质岩浆,部分原始地幔岩浆未经变异沿构造通道直接喷出地表形成碧玄岩、碱性橄榄玄武岩;部分原始地幔岩浆在上升过程中因停顿,原始地幔岩浆发生橄榄石分离结晶作用,部分橄榄石从岩浆中析出,最终岩浆喷出地表形成橄榄拉斑玄武岩.研究该区新生代玄武岩基本特征,探讨岩浆起源和岩石产生的构造环境对认识该区岩石圈地幔和软流圈性质具有重要意义.     

地幔柱成矿体系的基本特点——以峨眉大火成岩省为例

1 地幔柱及基成矿作用特点 地幔柱活动是固体地球各圈层间大规模物质交换一相互作用和大陆垂向增生的重要机制,可能导致岩石圈大规模隆升、伸展、甚至大陆裂解.由于地幔柱来源深、温度高,其上涌可以导致其自身、软流圈和岩石圈地幔广泛的减压部分熔融.短时间内产生巨量玄武岩浆,连续的玄武岩浆补给为大规模岩浆成矿作用提供必要的物质条件;强烈的岩浆活动还会启动地壳内部大规模热液循环,为地壳成矿物质的活化-迁移-热液成矿创造有力的环境条件和驱动力;巨量的溢流玄武岩本身具有很高的Cu、Ni、PGE(铂族元素)等元素背景值,为后期的热液活动成矿提供了物质基础.因此,地幔柱成矿主要包含岩浆成矿系列(Ni-Cu-(PGE)硫化物矿床、铬铁矿床、钛磁铁矿床、Nb-Ta-REE矿床),热液成矿系列和后期热液成矿系列(最典型的是自然铜矿床).有关的矿床是全球Ni和PGE的主要来源,Fe、Cu、Ti、REE、Nb等元素的重要来源.     

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.     

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″.     

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 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.     

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.