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1.
宝山铜铅锌多金属矿床是湖南重要的铅锌生产基地。矿床内矽卡岩型铜(钼)矿化受侏罗纪花岗闪长斑岩的控制,而主要的铅锌矿体则产于远离岩体的碳酸盐地层中,且缺乏可靠的矿化年龄限制。为了查明宝山铅锌矿体与花岗闪长斑岩之间的成因关系,文章对宝山花岗岩类中浸染状黄铁矿的硫同位素和钾长石的铅同位素,以及铅锌矿石萤石脉石的流体包裹体进行了测试和研究,并与前人报道的铅锌硫化物矿石的硫、铅同位素进行了对比,尝试为宝山铅锌矿化的物质来源及成因提供依据。研究表明,花岗闪长斑岩中浸染状黄铁矿的δ34S值为+1.5‰~+3.5‰,与铅锌矿石硫化物(方铅矿、闪锌矿及黄铁矿)相一致;同时,花岗岩类中钾长石的铅同位素组成206Pb/204Pb、207Pb/204Pb和208Pb/204Pb分别为18.4789~18.7668、15.6835~15.7220和38.7903~39.1035,具有壳源的特征,且与铅锌矿石硫化物的铅同位素分布范围相吻合。宝山矿床的硫、铅同位素特征表明,花岗闪长斑岩应是铅锌矿化的主要硫源及金属来源。宝山矿床铅锌矿石萤石中的流体包裹体具有低温(130~150℃)、低盐度(8%)的特征,可能是岩浆热液演化到晚期的产物。结合已有的有关资料加以对比和分析,研究认为,宝山铅锌矿床的成矿物质应来源于花岗闪长岩的岩浆期后热液,在热液演化晚期迁移到远端地层中沉淀,形成了宝山的主要铅锌矿体。 相似文献
2.
湘南宝山铅锌矿床硫、铅、碳、氧同位素特征及成矿物质来源 总被引：3，自引：1，他引：2
宝山铅锌矿床是湘南地区代表性矿床之一。宝山铅锌矿床的成矿作用与156~158 Ma的宝山花岗闪长斑岩密切相关。花岗闪长斑岩主要由古老地壳部分熔融而成。为确定成矿物质来源,文章系统研究了宝山铅锌矿床的硫、铅、碳、氧同位素组成特征。矿床中硫化物黄铁矿、闪锌矿、方铅矿的δ34S值呈狭窄的塔式分布,变化在-2.17‰~6.46‰之间,平均值为3.13‰。δ34S值总体表现为δ34S黄铁矿δ34S闪锌矿δ34S方铅矿,表明硫同位素分馏基本达到了平衡。矿石、花岗闪长斑岩和赋矿地层硫同位素对比研究表明,矿石中的硫主要由岩浆分异演化而来,岩浆中的硫主要来自古老地壳。矿石206Pb/204Pb、207Pb/204Pb和208Pb/204Pb比值分别为18.188~18.844、15.661~15.843和38.562~39.912,赋矿地层206Pb/204Pb、207Pb/204Pb和208Pb/204Pb比值分别为18.268~19.166、15.620~5.721和38.364~39.952。矿石铅同位素组成比地层中的更富放射性成因铅,矿石中部分铅来自宝山花岗闪长质岩浆,在成矿流体运移过程中有部分地层铅参与了成矿,岩浆中的铅主要来自古老地壳。热液方解石的碳、氧同位素组成介于岩浆和赋矿碳酸盐岩的碳、氧同位素之间,主要是由于岩浆流体和碳酸盐岩不同比例的水岩反应所致,测水组有机碳的加入造成了部分热液方解石δ13CPDB值偏低。 相似文献
3.
轮郎矽卡岩型铅锌矿床位于冈底斯斑岩铜矿带北侧的铅锌银成矿带。本文基于该矿床成矿地质条件,对矽卡岩型矿石中主要的金属矿物闪锌矿、方铅矿、磁黄铁矿和黄铁矿的S、Pb同位素特征进行研究,进一步探讨了矿床成矿物质来源,并与区域矿产特征进行对比。结果显示,矿石矿物的δ34S为-2.3‰~4.1‰,平均值为1.46‰,其频率直方图具有塔式分布特征,具幔源硫特征。矿石矿物的~(206)Pb/~(204)Pb为18.179~18.692,平均值为18.543;~(207)Pb/~(204)Pb为15.588~15.802,平均值为15.687;~(208)Pb/~(204)Pb为38.532~39.305,平均值为38.900;μ值在9.44~9.83之间,具有上地壳与地幔混合的造山带铅特征。轮郎矿床S、Pb同位素特征与冈底斯成矿带北亚带矽卡岩型矿床类似。成矿物质主要来源于念青唐古拉结晶基底片麻岩,部分来自造山带幔源物质。 相似文献
4.
西藏邦铺铅锌矿床S、Pb、C、O同位素组成及成矿物质来源研究 总被引：2，自引：0，他引：2
邦铺铅锌矿床系邦铺钼铜矿区斑岩矿化体外围形成的矽卡岩型铅锌矿床;矿石品位较富,成矿元素以铅锌为主,基本不含铜。文章以矿床中主要金属硫化物为研究对象,采用S、Pb同位素研究方法对矿床成矿物质来源进行探讨。结果表明,矿石金属硫化物δ34S值分布范围较宽,但主要集中于-3.7‰～-0.7‰之间,具塔式分布特征,硫主要来源于岩浆;矿石铅同位素组成稳定,为正常普通铅,矿石铅的高μ值(大于9.58)及构造环境演化图解中样品点的分布特征指示矿石铅主要来源于上地壳物质。与驱龙外围知不拉、甲玛矽卡岩矿体对比研究发现,3个矿床硫均为岩浆来源;而金属物质来源空间上则显示出一定的规律,驱龙—甲玛—邦铺矿集区由南向北壳源物质的混染作用不断增加;大理岩及方解石碳-氧同位素组成特征显示矿床成矿流体中碳源主要来自于岩浆,碳酸盐岩地层提供了部分成矿物质。 相似文献
5.
近年来，在相山铀矿田的西部牛头山地区深部发现了铅锌矿化体，其成因机制不明.为探讨牛头山铅锌矿化体物质来源，开展了硫化物原位硫同位素分析研究.根据硫化物矿物之间的充填和包裹关系判断，铅锌矿化体金属硫化物形成的先后顺序是:黄铁矿形成最早，方铅矿和闪锌矿次之，细脉状黄铜矿形成最晚.利用LA-MC-ICP-MS技术对矿化体中几种金属硫化物分别进行了系统的原位硫同位素分析.结果显示:黄铁矿、闪锌矿、方铅矿、细脉状黄铜矿的δ34S值介于-4.8‰~+5.4‰之间，各硫化物矿物之间硫同位素未达到完全平衡分馏，利用黄铁矿δ34S值得到的矿化流体δ34SΣS值（总硫同位素组成）近似为+3.7‰，与共生矿物对（闪锌矿-方铅矿）图解法得到的闪锌矿和方铅矿沉淀时矿化流体的δ34SΣS值（+3.2‰）相近，表明形成牛头山铅锌矿化体的矿化流体δ34SΣS值大约为+3.7‰，为岩浆硫.结合前人的岩浆岩年龄数据，我们判断该铅锌矿化体金属硫化物的硫可能主要来自次火山岩相花岗斑岩岩浆热液.同一薄片中闪锌矿δ34S值高于共生的方铅矿，表明两者硫同位素基本平衡，利用共生矿物对（闪锌矿-方铅矿）硫同位素温度计计算得出平衡温度为197~476℃，与前人通过脉石矿物流体包裹体得到的铅锌矿化流体温度基本一致.相山火山盆地与相邻的北武夷黄岗山、梨子坑等产铅锌矿的火山盆地具有相似的成矿条件及成矿物质来源，使相山火山盆地具有良好的铅锌多金属找矿前景. 相似文献
6.
黄沙坪矿床是湘南地区最大的铅锌多金属矿床.矿区内发育的花岗岩出露面积最大仅为0.6 km2,却导致铅、锌等金属巨量堆积,因此明确其成矿物质来源是理解矿床成因的关键.为探究矿床内硫的来源,本次研究在已有工作的基础上,对黄沙坪矿区石英斑岩和花岗斑岩进行了系统的全岩硫同位素分析,并与已有硫化物硫同位素数据进行了对比研究.结果显示,矿区石英斑岩和花岗斑岩的δ34 S范围分别为+4.1‰～+7.5‰和+4.9‰～+11.4‰,与典型的S型花岗岩硫同位素组成基本一致,而明显低于区内矿石δ34S值(+2.3‰～+17.5‰).综合上述,我们认为矿区岩浆硫的同位素组成应接近或略低于花岗质岩石全岩硫同位素组成,成矿物质硫除部分来自岩浆外,很大程度上有地层或膏盐层硫的加入,这可能是黄沙坪成为区域上最大铅锌多金属矿床的重要原因. 相似文献
7.
山东香夼斑岩型铅梓矿床的地球化学特征及成因探讨 总被引：1，自引：0，他引：1
香夼矿床是一个较为典型的斑岩型铅锌矿床,成矿母岩为燕山期花岗闪长斑岩,稀土元素呈现明显的Eu亏损,为地壳重熔型浅成、超浅成岩浆岩.矿床主要有用元素Pb、Zn、Cu、Ag、Au、S、Cd、Se、Te等均较高.矿床硫同位素δ~(34)S值靠近零,铅同位素组成表明矿石铅来源于岩浆,矿石铅与岩浆岩岩石铅组成一致,主要为上地幔来源的铅,有少量地壳铅参与成矿.H、O同位素表明成矿流体为岩浆水,成矿温度在230-350℃之间,方铅矿、闪锌矿单矿物微量元素显示出与岩浆热液型铅锌矿床相同的元素组合. 相似文献
8.
西秦岭李坝金矿床地质、同位素地球化学及其成因探讨 总被引：1，自引：0，他引：1
李坝金矿床位于西秦岭造山带中的礼-岷矿集区内,赋矿围岩为泥盆系浅变质细碎屑岩,矿床产于中川岩体的外侧热接触变质带内,矿体主要受断裂破碎带控制。本文在李坝金矿床地质特征研究的基础上,对赋矿围岩、花岗斑岩岩脉、矿石硫化物进行了LA-MC-ICPMS原位微区硫同位素测试及化学溶样法分析,对不同地质体的铅同位素进行了系统测定与示踪,测定了成矿流体的氢-氧同位素组成,并对与矿体相伴产出花岗斑岩脉进行了LA-ICP-MS锆石U-Pb定年。研究表明,李坝金矿床花岗斑岩脉中黄铁矿δ34S值范围为8.19‰~10.06‰,赋矿围岩中金属硫化物δ34S值范围为4.94‰~9.81‰,矿石硫化物的δ34S值范围为4.94‰~10.82‰,矿石硫化物的硫同位素组成与矿区花岗斑岩及赋矿围岩的硫同位素组成相似,暗示成矿流体中的硫源主要来自受改造或变质的地层岩石与岩浆热液硫的混合。不同地质体的铅同位素组成变化范围较小,在Zartman铅构造模式图解中,样品投影点均落于造山带与上地壳演化线附近,矿石铅投影点与赋矿围岩及矿区岩脉的投影点重合,表明矿石中的铅可能来源于赋矿围岩和岩浆作用的混合。氢-氧同位素研究表明,成矿流体可能为变质流体、岩浆流体及地层建造水的混合热流体。矿区花岗斑岩脉与矿体相伴产出,花岗斑岩的LA-ICP-MS锆石U-Pb年龄为223 Ma,与金矿化时间一致,暗示成矿作用与岩浆活动同时发生。李坝金矿床与矿区岩浆岩同为造山作用的产物,并且其矿床地质特征、同位素地球化学特征与造山型金矿床相似,为形成于秦岭造山带由碰撞向伸展转变环境下成矿物质来源复杂的造山型金矿床。 相似文献
9.
西藏驱龙斑岩铜矿S、Pb同位素组成:对含矿斑岩与成矿物质来源的指示 总被引：27，自引：0，他引：27
驱龙铜矿是西藏陆陆碰撞造山带冈底斯斑岩铜矿带内代表性矿床之一。本文对其含矿斑岩和矿石矿物进行了S、Pb同位素组成分析。驱龙矿床含矿斑岩与矿石矿物的硫同位素组成比较一致,含矿斑岩δ34S为-2.1‰~-1.1‰,黄铜矿δ34S为-6.3‰~-1.0‰,均值-2.76‰;硬石膏δ34S为 12.5‰~ 14.4‰,平均 13.4‰。成矿热液中的硫同位素基本达到了平衡,显示出岩浆硫组成特点。含矿斑岩的206Pb/204Pb范围为18.5104~18.6083,207Pb/204Pb变化于15.5946~15.7329之间,208Pb/204Pb为38.6821~39.1531之间;矿石矿物黄铜矿的206Pb/204Pb、207Pb/204Pb、208Pb/204Pb分别为18.4426~18.5909、15.5762~15.6145、38.5569~38.8568。含矿斑岩与矿石矿物的铅同位素组成比较一致,它们的变化幅度较小,应具有相同的起源与演化历史。无论是岩石铅还是矿石铅,在铅构造模式图上均位于造山带铅演化曲线上。驱龙矿床硫、铅同位素数据暗示,成矿物质主要来自深源岩浆,含矿斑岩起源于西藏造山带加厚的下地壳熔融,具有幔源成分的混染。 相似文献
10.
肖家营子矿床是一个与细粒闪长岩有关的矽卡岩型钼铁矿床.采用ICP-MS法对该矿床主要矿石矿物和围岩中的铂族元素进行分析表明:PGE元素在不同矿物中的含量变化较大,在辉钼矿和黄铁矿中比较富集,而在磁铁矿、石榴子石及细粒闪长岩、白云岩中则含量较低,这与PGE趋向在硫化物中富集的行为有关.不同矿物或岩石的原始地幔标准化曲线呈似W型,显示出Ir和Pt负异常,Ru正异常.辉钼矿和黄铁矿中的PGE分异较明显,具有相似的配分模式;磁铁矿、石榴子石、细粒闪长岩和白云岩内的PGE分异不明显,具有相近的IPGE配分模式.硫同位素分析结果显示,多数硫化物的δ34S值为3‰～5‰,与赋矿细粒闪长岩的δ34S值(1.1‰～3.5‰)较相似.PGE和硫同位素分析表明,肖家营子矿床不同成矿阶段成矿物质的来源不同,矽卡岩阶段的成矿物质主要来自细粒闪长岩和白云岩,热液硫化物阶段的成矿物质不全是来自细粒闪长岩和白云岩,还可能有壳幔混源物质的加入. 相似文献
11.
Guboglo M. N. 《GeoJournal》1980,4(1):53-58
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. 相似文献
12.
Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 《《幕》》2008,31(3):315-318
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. 相似文献
13.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
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″. 相似文献
14.
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. 相似文献
15.
Fouad N. Ibrahim Dr. 《GeoJournal》1988,17(1):133-141
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. 相似文献
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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。 相似文献
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郯庐断裂南段研究进展与断裂性质讨论 总被引：13，自引：3，他引：13
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。 相似文献
20.
The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
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. 相似文献