千里山花岗岩体地质地球化学及与成矿关系

千里山花岗岩由似斑状黑云母花岗岩、等粒黑云母花岗岩和花岗斑岩组成。前两期岩体分别与两期钨多金属矿化有关，后一期与铅锌银成矿密切相联。两套花岗岩虽然均来自地壳，但取于不同源地。该岩体既为富Ｆ、Ｌｉ，Ｒｂ，Ｂｅ，Ｇａ的ＢＥＬＩＦ花岗岩，又是富Ｕ，Ｔｈ的高热花岗岩。     

赣北大湖塘钨矿成岩成矿物质来源的矿物学和同位素示踪研究

赣北大湖塘超大型钨矿位于九岭钨多金属矿集区东部。本文对大湖塘钨矿石门寺矿段矿物学特征进行了系统的研究,结合同位素示踪分析了成岩成矿物质来源。岩相学研究表明,石门寺矿段蚀变以黑云母化、云英岩化及碱交代(钾长石化、钠长石化)作用为主。黑云母化的过程中释放了一定量的挥发分,云英岩化和碱交代作用除萃取部分的成矿物质外,使岩体中的Ca2+大量活化迁移。晋宁晚期黑云母花岗闪长岩与燕山中期似斑状花岗岩、花岗斑岩矿物成分研究表明:(1)斜长石普遍富钠,似伟晶岩壳主晶为钾长石,客晶为钠长石;(2)黑云母具有富铁贫镁的特点,黑云母花岗闪长岩及似斑状花岗岩中的黑云母均为铁质黑云母,花岗斑岩中黑云母为铁叶云母。黑云母成分指示大湖塘石门寺矿段花岗岩类均为过铝质S型花岗岩,成岩物质均为壳源。石英氢、氧同位素及黑钨矿氧同位素研究表明成矿流体为岩浆水。黄铜矿、辉钼矿硫同位素表明成矿流体中硫来自于岩浆。结合前人研究成果,本文认为富钨的双桥山群浅变质岩在燕山中期发生了部分熔融,产生了高分异的富含钨元素及挥发分的岩浆,岩浆分异演化过程中形成的含矿热液使侵入体自身及围岩发生大规模的蚀变作用,进而在燕山中期侵入岩的内外接触带形成了大湖塘超大型钨多金属矿床。     

洛宁花山岩体地球化学特征及成因的探讨

出露在河南省洛宁县境内的花山花岗岩复式岩体从早到晚依次划分为似斑状黑云母二长花岗岩，似斑状黑云母角闲石英二长岩，中细粒角闪黑云母二长花岗岩三个阶段。本文简要叙述了花山岩体各阶段岩石的地球化学特征，并结合已有基础地质、同位素资料，探讨了花山岩体的成因机制。结果表明，花山岩体属Ｉ型花岗岩类，为大陆板块内部的同熔型花岗岩，形成花山岩体的岩浆来源于混有地幔物质的太华群地层。     

江西永平铜矿区花岗岩热液蚀变与岩石成因:矿物化学、元素地球化学和Sr-Nd-Hf同位素制约

永平铜矿床是位于华南钱塘江-信江断裂坳陷带中的一个大型铜矿床.矿区内出露的岩浆岩主要有似斑状黑云母花岗岩体和少量石英斑岩脉,黑云母花岗岩岩体内及接触带发育斑岩型和矽卡岩型铜钼钨多金属矿化.对岩体中黑云母的电子探针成分分析表明,似斑状黑云母花岗岩中黑云母具有富镁贫铁高钛的特点,Fe/(Fe Mg)为0.21～0.33,TiO2含量为2.12%～4.28%;而石英斑岩脉中黑云母更加富镁贫铁,Fe/(Fe MS)为0.10～0.15,TiO2含量为2.43%～3.86%.黑云母的化学组成表明花岗质岩浆形成时的氧逸度很高,与长江中下游地区其他含铜花岗质岩体相吻合.永平花岗岩体遭受了较强的热液蚀变作用,部分黑云母蚀变为绿泥石.石英斑岩中绿泥石具有富铁贫镁低钛的特征(Fe/(Fe Mg)=0.72～0.76;TiO2=0.02%～0.06%),其形成温度为139～224℃.而似斑状黑云母花岗岩中绿泥石相对贫铁富镁高钛(Fe/(Fe Mg)=0.36～0.44;TiO2=0.05%～0.36%),形成温度稍高,为229～346℃,与该矿床流体包裹体研究获得的成矿温度(220～400℃)基本吻合.Sr-Nd-Hf同位素综合研究表明,永平似斑状黑云母花岗岩具有变化较大且相对较高的εHf(t)值(-0.1～-10.3)和εNd(t)值(-5.83～-7.95),反映岩石具有明显的壳幔混合成因特征.而石英斑岩的εHf(t)值(-8.4～-12.5)和εNd(t)值(-9.93～-10.2)均稍低于似斑状黑云母花岗岩,反映其形成过程中幔源物质贡献相对较小.永平岩体的地壳端元很可能就是该区中元古代基底地层重熔的产物.     

中缅毗邻区金腊Pb-Zn-Ag多金属矿田花岗岩锆石U-Pb定年与地球化学特征

位于中缅毗邻区的金腊铅锌银多金属矿田大地构造上处于保山—掸泰地块东缘,勐统—耿马—西盟元古宙—古生代被动大陆边缘活动带南段。与矿化有关的花岗岩(简称金腊花岗岩)包括老厂似斑状角闪二长花岗岩、勐林山似斑状黑云二长花岗岩和南腊碱长花岗斑岩。文中系统研究了上述岩石的主量元素、稀土元素、微量元素、成矿元素和锆石U-Pb同位素年龄等特征,从构造岩浆演化的角度,探讨上述岩体之间内在联系、成因演化以及与成矿的关系:(1)在金腊花岗岩三种岩石类型中,老厂似斑状角闪二长花岗岩和勐林山似斑状黑云二长花岗岩的锆石同位素U-Pb年龄皆为(45±1)Ma,形成于岩浆结晶分异早期阶段的深成环境,而南腊碱长花岗斑岩的锆石同位素U-Pb年龄为(43.41±0.78)Ma,形成于岩浆结晶分异晚期阶段的浅成环境。(2)主量元素和微量元素(稀土元素和某些微量元素(Zr/Hf、Nb/Ta、Rb/Sr、Rb/Ba、K/Rb、(Rb/Yb)N、Sr*、K*和Zr*)),结合U-Pb同位素定年研究表明,本区花岗岩形成于喜马拉雅同碰撞造山成矿作用末期局部拉张构造环境,并分别代表了构造岩浆演化过程中不同演化阶段岩浆分异结晶的产物。(3)上述三类花岗岩样品皆位于S型花岗岩区,但从老厂似斑状角闪二长花岗岩,勐林山似斑状黑云二长花岗岩,到南腊碱长花岗斑岩,样品分布逐渐远离"I"型花岗岩和"S"型花岗岩的分界线,这表明自老厂似斑状角闪二长花岗岩至勐林山似斑状黑云二长花岗岩,到南腊碱长花岗斑岩幔源组分逐渐减少。(4)相对中国花岗岩,南腊碱长花岗斑岩不仅更富集W、Cu、Bi、Sb、Mo、Sn、Ag、Pb和Au等成矿元素,而且还强烈富集F、B和As等矿化剂元素,因此,碱长花岗斑岩是最有成矿远景的岩体。     

中甸火山-岩浆弧燕山期热林复式岩体演化 与Ar-Ar 定年及铜钼矿化

产于中甸印支期火山一岩浆弧北东缘的燕山期热林复式岩体,从早至晚边部到中部划分出主期由细粒似斑状二长花岗岩→中粒似斑状二长花岗岩和边部补充期二长花岗斑岩5个侵入体组成的同源岩浆细粒→中粒→斑状结构演化系列.岩体岩石化学、稀土和微量元素总体反映为同熔型花岗岩特征.在复式岩体Ⅱ号侵入体中粒似斑状二长花岗岩中获黑云母Ar-Ar同位素等时年龄81.7±1.1Ma,坪年龄82.01±0.86 Ma,属燕山晚期侵入体.铜钼矿主要产于晚期侵入体中,边部细粒花岗岩和角岩内带具有细脉状黄铜矿、团块状辉钼矿化;中部发生二长花岗(斑)岩热液蚀变充填交代辉钼矿化--辉钼矿石英细脉、中粗晶浸染状;以及沿裂隙发育岩浆期后含矿热液充填交代辉钼矿化,构成燕山期花岗斑岩铜钼成矿亚系列.成因类型:蚀变花岗斑岩、石英脉型和角岩型3种,指示了燕山期二长花岗斑岩类具有较好的铜钼找矿潜力.     

粤北大宝山矿区船肚岩体和大宝山花岗斑岩锆石LA-ICP-MS U-Pb年龄及多阶段成矿分析

粤北大宝山矿床矿区出露船肚和大宝山矿化岩体。本文分析了两个岩体矿物组成特征和锆石LA-ICP-MS U-Pb年龄。船肚岩体为似斑状结构,块状构造,主要由似斑状花岗岩、似斑状二长花岗岩及似斑状花岗闪长岩等组成,和云英岩型及矽卡岩型Mo-W矿化紧密共生。大宝山岩体为斑状结构,块状构造,主要由碱长花岗斑岩、普通花岗斑岩、二长花岗斑岩及花岗闪长斑岩组成,矿物组成和船肚岩体的基本相同,和细脉浸染状Mo-W矿化紧密共生。船肚似斑状二长花岗岩和大宝山二长花岗斑岩锆石LA-ICP-MS U-Pb年龄分别为162.1±1.6 Ma,MSWD=2.72和165.8±2.0 Ma,MSWD=1.38。据船肚和大宝山岩体矿物组成基本相同、岩石结构不同及两者锆石Th/U比值不同和U-Pb年龄存在约4 Ma左右时差,提出大宝山矿区在燕山期发生了两阶段岩浆成矿事件,第一阶段岩浆成矿事件发生在166 Ma左右,形成大宝山斑岩型矿床,第二阶段岩浆成矿的形成时间约为162 Ma左右,形成船肚似斑状二长花岗岩及与岩体紧密共生的矽卡岩型和云英岩型矿化;大宝山斑岩体和船肚似斑状岩体是同一岩浆房两次脉动侵入形成的。     

甘肃北山拾金坡花岗岩特征 及其与金成矿的关系

通过对拾金坡岩体宏观地质特征、岩石矿物学、岩石化学以及地球化学成果的全面分析,通过对区域成矿地质背景的研究,总结了该区金矿的控制因素。区内金成矿主要受岩体和构造控制。岩体是成矿的最主要因素,矿化与岩体有密切的时空关系,区内大多数金矿床产在拾金坡岩体的边缘。拾金坡复式花岗岩由早期到晚期可分出闪长岩、似斑状二长花岗岩和黑云母二长花岗岩共3期岩浆活动。岩石学和地球化学研究表明该岩体为下地壳或上地幔源,属Ⅰ型或同熔型;岩体相对富集轻稀土,δEu值为0.45～0.99。加里东晚期似斑状二长花岗岩提供了成矿物质,海西早期钾长花岗岩对含矿热液的运移起到了积极作用。处于深处的钾长花岗岩在上升过程中产生了含矿热液,并且在似斑状花岗岩中形成了一系列断层,这些断层为成矿流体的运移和富集提供了空间。海西期的构造岩浆活动不但为含金热液在二长花岗岩中的上升运移开辟了通道,而且为金矿化提供了热源,在似斑状二长花岗岩中形成石英脉型金矿床。     

西藏甲玛矿床南坑高分异Ⅰ型花岗斑岩及黑云母矿物学特征

高硅花岗岩对于理解浅部岩浆房的行为具有重要意义。本文对西藏甲玛矿区南坑矿段的花岗斑岩开展了岩相学、岩石地球化学及黑云母矿物学研究。结果显示,该花岗斑岩具有高SiO2(73.39%~77.99%)、高K2O(4.34%~6.45%)和低P2O5(0.03%~0.06%)特征,铝饱和指数为0.97~0.98,富集Rb、Th、U和Pb,明显亏损Ba、Nb、Ta、Sr、P、Ti和Eu等,属准铝质高分异I型花岗岩类;其中的黑云母具有高Al2O3(9.87%~10.92%)、高MgO(13.38%~14.64%)、高F(0.56%~1.11%)和高Cl(0.07%~0.12%)特征,Mg#为0.61~0.63,属镁质黑云母,黑云母源区为壳幔混合源。研究认为,该区花岗斑岩可能为甲玛矿区浅部埃达克质二长花岗斑岩的岩浆经矿物结晶分异演化出高硅残余熔体,并以岩脉形式上侵就位,而残留在岩浆房的物质结晶形成似斑状二长花岗岩,二者构成互补的关系,即主体为似斑状二长花岗岩,补体为高分异花岗斑岩。     

西藏山南地区明则斑岩钼矿床蚀变矿化特征与成矿时代

明则斑岩钼矿床位于冈底斯成矿带的东南缘,雅鲁藏布江缝合带北侧.矿区内主要出露有钾长花岗岩、黑云母二长花岗岩、花岗闪长岩、似斑状二长花岗岩及花岗斑岩,其中花岗斑岩为成矿岩体.围岩蚀变较为强烈,主要的蚀变特征有:钾化、硅化、绿泥石化、高岭土化和矽卡岩化,而且各种蚀变现象具有垂向分带特征,其中矽卡岩化主要发育在地表浅部,岩体...     

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。     

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.     

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。