共查询到20条相似文献，搜索用时 62 毫秒
1.
IrinaP.Solovova Theodoros Ntaflos Andrei Girnis Natalya N.Kononkova Vyacheslav V.Akinin 《中国科技期刊研究》2007,23(1):83-92
Melt and fluid inclusions were studied in the minerals of Cenozoic olivine melanephelinites from the Chukehi Peninsula, Russia. The rock contain several generations of olivine phenocrysts varying in composition at mg=0.88 - 0.77. The phenocrysts bear fluid and melt inclusions recording various stages of melt crystallization in volcanic conduits and shallow magma chambers. Primary fluid inclusions are CO2-dominated with a density of up to 0.93 g/cm^3. All fluid inclusions are partially leaked, which is indicated by haloes of tiny fluid bubbles around large fluid inclusions in minerals. Melt inclusions contain various daughter crystals, which were completely resorbed in thermometric experiments at about 1230~C. Assuming that this temperature corresponds to the entrapment conditions of the CO2 fluid inclusions, the minimum pressure of the beginning of magma degassing is estimated as 800MPa. Variations in the compositions of homogenized silicate melt inclusions indicate that olivine was the earliest crystalline phase followed by clinopyroxene, nepheline and orthoclase. This sequence is in agreement with the mineralogy of the rocks. The melts are strongly enriched in incompatible trace elements and volatiles （in addition to CO2 , high C1, F, and S contents were detected）. There are some differences between the compositions of melts trapped in minerals from different samples. Variations in SiO2 , FeO, and incompatible element contents are probably related to melt generations at various levels in a homogeneous mantle reservoir. 相似文献
2.
Fluid inclusion study has been carried out for the carbonatite dykes/veins and the ore-hosted dolostone of the Bayan Obo superlarge REE-Fe-Nb deposit in order to provide the evidence and constraint for their origin. Based on the detailed geological observation and mineralogical investigation, the heating and cooling stage and laser Raman spectroscopy were mainly used for the laboratory work of this study. Following results have been obtained： （ 1 ） The discovery of melt and melt-fluid inclusions from carbonatite dykes/veins in the Dulahara and Jianshan Mountains, combined with the fine-grained （aplitic） texture of rocks, as well as the types and features of fluid inclusions such as CO2 enrichment, higher homogenization temperature, provides a direct evidence for the magmatic origin of these dykes/veins. （2） The carbonatite dykes/veins distributed in two regions, nearby the axis of the Kuangou anticline and in the east to Bayan Obo town, mainly show coarse-grained texture. No melt inclusion was found, and the fluid inclusions possess features of less CO2, lower homogenization temperature and higher salinity. They are tentatively identified as veins formed by some carbonate-rich hydrothermal solution. （3） Bedding carbonate layers/lens within the hanging wall and foot wall of ore-hosted dolostone, previously recognized as of magmatic origin, mainly composed by dolomite. The existence of single phase pure aqueous inclusions with very low homogenization temperature indicates their sedimentary origin. （4） The ore-hosted dolostone possesses apparent bedding and laminated structures. No melt inclusion was found, but, both single phase pure aqueous inclusions and CO2 bearing muhi-phase fluid inclusions coexisted in dolostones. In the direction towards ore-bodies, the homogenization temperature and CO2 contents of fluid inclusion show an increasing tendency. It indicates the sedimentary origin of dolostone superimposed by late fluid metasomatism. 相似文献
3.
Kingsley Burlinson 《中国科技期刊研究》2007,23(1):65-71
The acoustic decrepitation method heats a small monomineralic sample and counts pressure impulses as the inclusions burst when they develop high internal pressures. For aqueous fluids, the decrepitation temperature is correlated with the homogenisation temperature, but gas rich fluids give a distinct and characteristic low temperature decrepitation peak which can be used to recognize gas rich fluid inclusions. This information is useful in exploration for Au deposits, which are frequently associated with CO2 rich and sometimes CH4 rich fluids. This distinctive decrepitation occurs because the CO2 rich inclusion fluids expand according to the gas law and develop internal pressures high enough to burst the host mineral grain at temperatures well below their homogenisation temperatures. In contrast, aqueous fluids condense to a liquid and vapour phase during post-entrapment cooling. Upon subsequent heating their internal pressures do not increase significantly until after homogenisation to a single phase occurs and hence they do not decrepitate ＂prematurely＂ as gas rich inclusions do. This behaviour is usually regarded as an annoyance in conventional microthermometric homogenisation studies, but can readily be used as an exploration aid to find mineralisation deposited from such gas rich fluids. Decrepitation results on samples from Cowra Ck, NSW, Australia, which have also been microthermometrically measured for CO2 content, show that amounts of less than 5 mole % CO2 are easily distinguished by decrepitation and amounts as low as 1 mole % CO2 may be determinable. Examples of the use of acoustic decrepitation in the study of 6 gold mines in the Shandong and Hebei provinces of China are discussed. 相似文献
4.
IrinaA.Andreeva Vyacheslav I.Kovalenko Vladimir B.Naumov 《中国科技期刊研究》2007,23(1):73-82
Crystalline and melt inclusions were studied in garnet, diopside, potassium feldspar, and sphene from the garnet syenite porphyry of the carbonatite-bearing complex Mushugai-Khuduk, southern Mongolia. Phlogopite, clinopyroxene, albite, potassium feldspar, sphene, wollastonite, magnetite, Ca and Sr sulfates, fluorite, and apatite were identified among the crystalline inclusions. The melt inclusions were homogenized at 1010℃～1080℃ and analyzed on an electron microprobe. Silicate, salt, and combined silicate-salt melt inclusions were found. Silicate melts show considerable variations in SiO2 concentration （56 to 66wt% ）, high Na2O ＋ K20 （up to 17wt% ）, and elevated Zr, F, and Cl contents. In terms of bulk rock chemistry, the silicate melts are alkali syenites. During thermometric experiments, salt melt inclusions quenched into homogeneous glasses of predominantly sulfate compositions containing no more than 1.3wt% SiO2. These melts are enriched in alkalis, Ba, Sr, P, F, and Cl. The investigation of the silicate and salt melt inclusions in minerals of the garnet syenite porphyries indicate that these rocks were formed under influence of the processes of crystallization differentiation and magma separation into immiscible silicate and salt （sulfate）liquids. 相似文献
5.
《国家科学评论(英文版)》2015,(3)
<正>Early Cretaceous gold deposits in the North China Craton and the famous Carlin-type gold deposits in Nevada are given the name‘decratonic gold deposits’[1].his is the irst new type of ore deposit proposed in the last 20 years.his new type of deposit introduces a concept that may change perspectives and provide fresh opportunities for gold deposit research and exploration.Cratons are stable ancient crustal domains characterized by thick lithospheric mantle roots(150 km),weak tectonism,and litle or no magmatic activity within their boundaries.Since their sta- 相似文献
6.
Well S provides a good opportunity to investigate the petroleum filling history in Tazhong North Slope. Petrographic investigations suggest that bitumen, oil, and petroleum inclusions coexist in Silurian sandstones from well S, reflecting a complicated reservoir filling history in the study area. Integration of organic geochemistry and fluid inclusion analysis shows that the Silurian reservoir has experienced three episodes of petroleum charge, that is from the late Silurian to the early Devonian, the early-middle Triassic and the Paleogene, respectively. The present-day reservoir fluids in the Silurian are the mixtures generated in multiple （ at least two） episodes of petroleum charge. The oil charging into Silurian resevior in the early period had experienced considerable degradation, and was mixed with later non-degraded oil. 相似文献
7.
Halite precipitation with water and air temperature was observed in detail, and homogenization temperature of fluid inclusions in halite formed in ancient and modem Chaka Salt Lake was studied. Halite precipitates mainly in August every year and largely precipitates between 13 and 15pm at one day when water temperatures reach 20℃ but can seldom reach 30℃. Homogenization temperatures of fluid inclusions in halite formed in Chaka Salt Lake range from 14℃ to 38℃ with an average of 23.7℃. The number of inclusions appears an obvious peak value at homogenization temperatures between 18 - 25℃, which probably represent the water temperature in which halite mainly precipitates when water temperatures reach 20℃. Therefore, homogenization temperatures of fluid inclusions in halite formed in Chaka Salt Lake can wall reflect the water temperature. 相似文献
8.
Abundant melt-and fluid inclusions occur in corundum megacrysts of alkaline basalt from the Changle area, Shandong province, eastern China. One type of melt inclusions, i.e. muhiphase melt inclusions （glass ＋ bubbles ＋ daughter minerals） were identified , which occur along growth zones of host corundum megacrysts. Microthermometry and laser Raman microprobe analysis were performed on the melt inclusions. The bubbles within the melt inclusions are confirmed to be CO2-rich phase and the daughter minerals are probably silicates, such as augite and okenite. The results of high temperature homogenization experiment strongly suggest that two immiscible melts, i.e. a H2O-and CO2-rich melt and an anhydrous and CO2-poor melt were trapped by melt inclusions in corundum megacryst. 相似文献
9.
《中国科学院院刊(英文版)》2011,25(1):74-75
Research aim The creative group is devoted to the fundamental research and application of the rare earth functional materials and strives to meet the national strategic needs in this field. As China is rich in rare earth resources, the 相似文献
10.
Guoxiang Chi Pei Ni 《中国科技期刊研究》2007,23(1):33-37
The composition of fluid inclusions in the H2O-NaCl-CaCl2 system has been generally graphically estimated using the melting temperatures of hydrohalite （ Tm-HH ） and ice （ Tm-ice）. Here we present two equations that can be used to calculate the relative proportion of NaCl （ i. e. , NaCL/[ NaCl ＋ CaC12 ] , or XNacl ） and the total salinity （ i. e. , NaCl ＋ CaCl2, wt% ） for fluid inclusions with ice as the last melting phase. XNacl can be calculated from Tm-HH using the following equation： y = （a＋bx）^-1/c where y is XNacl, x is Tm_HH , a =0. 33124402, b =-0. 031518028, and c =0. 22932736. In the cases where only Tm-ice is measured and Tm-HH is not known, Tm-ice can be used as the maximum possible Tm-HH to calculate the maximum value of XNacl using the above equation. In these cases, the following equation can be used to calculate the maximum total salinity： y=（a＋bx＋cx2） l where y is salinity, x is Tm-HH , a =0, 057184817, b =0. 00078565757, and c = 5. 7262766E-6. Because the isothems in the field of ice are sub-parallel to the NaCl-CaCl2 binary side in the H2O-NaCl-CaCl2 ternary system, the errors in salinity calculation introduced by the above approximation are small （ less than 2 wt% ）. A Windows program for calculation of XNacl and salinity is available at ： http ：//uregina. ca/-chiguox. 相似文献
11.
西秦岭造山带内的甘肃阳山金矿是我国最新发现的规模最大的金矿床。矿床受EW韧脆性剪切带控制，赋矿围岩为泥盆系碳质碳酸盐-千枚岩-板岩和侵入其中的花岗斑岩脉。流体成矿过程包括：形成石英-绢云母-黄铁矿组合的早阶段，形成石英-黄铁矿-毒砂和石英-毒砂-黄铁矿以及石英-碳酸盐-辉锑矿-自然金组合的主戍矿阶段，形成碳酸盐-石英网脉的晚阶段。早阶段流体包裹体以含CO2包裹体为主，CO2含量为7．3％-21．5mol％，均一温度集中于270℃～300℃，盐度〈3wt．％NaCleqv；主阶段发育纯CO2包裹体、水溶液包裹体和少量含CO2包裹体，均一温度集中于210℃～270℃，盐度集中在〈2wt，％NaCleqv和3～5wt，％NaCleqv两个范围；晚阶段只发育水溶液包裹体，均一温度集中在160℃-210℃，盐度〈3wt．％NaCleqv。主阶段流体包裹体类型的多样性、相似的均一温度和流体盐度的双峰特征均指示流体沸腾现象的存在，其流体包裹体捕获温度为210℃～375℃，压力为85～222MPa；赋矿断层的阀门式活动导致主阶段流体系统交替于静岩和静水压力之间，成矿深度为8．5km左右，成矿流体系统发育在早侏罗世大陆碰撞造山过程。矿床地质特征类似于卡林型金矿，但赋存于蚀变花岗斑岩中矿体既非造山型，也不同于卡林型，成矿流体具造山型矿床特征。因此，阳山金矿可能代表一种新的金矿类型，建议称为“阳山型金矿”。 相似文献
12.
玲珑金矿位于胶东半岛招．掖成矿带东部，是我国典型的超大型含金石英脉型金矿。成矿过程可划分为早、中、晚三个阶段，金主要在中阶段沉淀。早阶段流体包裹体为纯CO2型（LCO2＋VCO2〉90％）和富CO2型（10％≤LCO2＋VCO2≤90％），中阶段为纯CO2型、富CO2型、富H2O型，晚阶段为水溶液包裹体。从早到晚，包裹体均一温度分别集中在240℃～360℃、220℃-360℃、180℃-260℃和80℃-180℃，盐度分别集中在3．4％-10．4％、3．0％-10．2％、4．0％-14．6％和2．4％-5．0％NaCleqv；早、中阶段流体盐度随温度降低而升高。中阶段第一世代石英中大量水溶液包裹体和富CO2包裹体共生，指示流体强烈沸腾。从早到晚，流体包裹体的变化记录了成矿流体性质和构造环境的演化。早阶段石英中沿X型节理发育面型包裹体群，既记录了石英脉遭受的剪切变形事件，又记录了同构造流体作用。而充填于张性裂隙的黄铁矿为主的多金属硫化物．石英组合则表明主成矿期构造环境由压性向张性转化，成矿流体系统减压沸腾、逐步开放，并导致金等成矿物质大量沉淀。结合区域构造演化和成矿时间，认为玲珑金矿成矿系统发育在应力场由挤压向伸展转换的构造背景，流体压力变化滞后于构造应力场变化，流体成分以低盐度、富CO2为特征，应属典型的造山型金矿系统。 相似文献
13.
红石金矿床是新疆东天山康古尔塔格金矿带中的代表性矿床之一，本文对其进行了比较系统的流体包裹体和稳定同位素研究。流体包裹体研究结果表明，红石金矿床的成矿流体为中低温、低盐度、中低密度的富CO2流体。石英氢同位素组成δDSMOW为-104‰～-63‰，石英氧同住素组成δ^18OPDB为13.8‰～15.5‰、δ^18O水为-1.7‰～6.1‰。方解石碳同位素组成δ^13CPDR为-3.5‰～-2.7‰，方解石氧同位素组成δ^180PDB为-28.9‰～-26.5‰、δ^18OSMOW为1.1‰～3.5‰。H、O、C同位素组成特征指示红石金矿床成矿流体主要起源于深部，后期混合有大气水。黄铁矿硫同位素组成δ^34为-11.5‰～3.8‰，集中于0.4％～3.8‰，平均值为1.73‰，指示了成矿物质中的硫具有接近陨石硫的深源特征。红石金矿床的成矿作用可概括为富含成矿元素的深源流体在区域剪切构造作用下沿剪切系统不断向上运移，逐渐与浅部流体混合并与围岩发生交代蚀变作用，由于物理化学条件的改变，成矿元素最终在剪切扩容空间中富集成矿。 相似文献
14.
庞家河-文家庄金成矿带位于秦岭海-印支褶皱系西北边缘,属于札县－柞水冒地槽褶皱带东段西部。主要由北部庞家河－野猪窖金矿带和南部三台山－文家沟金矿带组成,分布有多个金矿床和金矿体。矿体分布受区域韧性断裂控制明显,具有成带分布、多层位矿化的特点,矿化单一,与蚀变关系密切。区域性韧脆性断层及次级断层和含矿地层是区内金矿主要的控矿因素。 相似文献
15.
新疆东天山剪切带型金矿床时代研究 总被引：1，自引：0，他引：1
东天山造山带中部的秋格明塔什-黄山巨型韧性剪切带内三个典型的剪切带型金矿床——康古尔金矿床、红石金矿床和红山金矿床的同位素年代学研究表明，金矿床成矿作用和剪切带后期的走滑剪切变形作用在时间上具有强烈的耦合关系。秋格明塔什．黄山韧性剪切带剪切变形作用主活动期的时代为262.9～242.8Ma，而剪切带型金矿床金成矿作用发生在261.0～246.5Ma之间，恰好落在剪切变形作用主活动期的时代范围之内。这种强烈的耦合关系证明了秋格明塔什-黄山韧性剪切带晚期的右行走滑剪切变形作用才是剪切带内一系列金矿床成矿作用的主因。金成矿和右行走滑剪切变形之间的时间耦合关系在不同部位还有不同的表现。在剪切带中-西段的康古尔地区，快速抬升发生在261.5～262.9Ma，而康古尔金矿床主成矿期时代范围是261.0～252.5Ma，可以看出，康古尔金矿床成矿作用刚好发生于剪切带中-西段快速抬升之后。在剪切带东段，快速抬升发生在247.1～246.9Ma期间，位于该剪切带东段北外带的红山金矿床主成矿期的年龄范围是246.9～246.5Ma，表明该金矿也是在剪切带东段快速抬升冷却之后形成的。金矿石Ar-Ar同位素年代学研究未能得到可靠的和早期韧性推覆剪切变形事件相对应的年龄，推测在晚石炭世一早二叠世发生的韧性推覆剪切变形事件可能仅导致了包括金在内的金属元素的初步富集，但由于高温不利于金属元素沉淀和挤压环境不易存在容矿空间等不利因素的影响，导致此阶段并没有形成有工业开采价值的金矿床。只是到了华力西晚期—印支早期，在原韧性推覆剪切带内发生了走滑剪切变形活动，并产生了快速抬升冷却降温到350℃后，在地体缓慢冷却阶段，在脆-韧性剪切带内才有足够的空间和时间形成金矿床。 相似文献
16.
白云金矿接替资源勘查项目共布设22条勘查线,实施49个钻孔,控制网度160米×160米,金资源量估算严格按照《岩金矿地址勘查规范》要求执行,共计探获333级别金金属量15777千克。结合外围相邻金矿区,无疑已经构成了一个特大型金矿床。白云金矿接替资源勘查为保障辽宁基础工业冶炼加工原料供求,推动辽宁老工业基地振兴,做出了重大的历史性贡献。 相似文献
17.
镇龙山小圣矿区发育锑金等多种矿体,严格受断裂控制,且以岩体为中心存在明显的元素分带。通过分析,认为其成矿物质来源与地层和岩浆岩都有密切关系。结合华南板块构造演化史,认为镇龙山锑金多金属矿床的成因为先改造富集,后受岩浆热液富集并沿断裂充填成矿。 相似文献
18.
本文介绍了国家图书馆馆藏视听文献的历史,同时也对馆藏文献的种类、载体及其载体设备进行了简单的叙述,对从未接触过此类载体和设备的人是一个很好的感性认识,尤其是那些传统载体及其设备,也是不多见的描述和介绍。对于载体的保存措施本文也做了阐述,集多年的理论和实践的综合,在探讨长期保存和数字化道路上,是经历和经验的总结。本文讲述了国家图书馆视听数字馆藏的建设,除了介绍馆藏视听文献的数字化,对馆内各种讲座视频及其数字化也做了评述,并列出具体数字化技术参数。最后是对推进馆藏视听文献数字化及其存储的设想,流媒体推荐AVC MPEG4格式,网络存储推荐SAN架构,光盘存储推荐24K金盘。以上的观点和分析,希望能为其他单位的试听文献数字化提供几点参考。 相似文献
19.
邓格庄金矿是胶东牟平-乳山金成矿带内第二大石英脉型金矿，金主要产于黄铁矿和多金属硫化物石英脉/细脉中。流体包裹体研究表明，邓格庄金矿不同蚀变带岩石和各成矿阶段金矿石中的流体包裹体主要有三种类型：H2O-CO2包裹体、CO2-H2O±CH4包裹体和H2O溶液包裹体。早期乳白色石英中主要赋存原生的H2O-CO2包裹体和次生的CO2-H2O±CH4包裹体；成矿期黄铁矿石英脉和多金属硫化物石英脉中的CO2-H2O±CH4包裹体主要为原生，随机分布，气液比变化较大，有时出现不同相比例的包裹体共存现象，而H2O溶液包裹体明显沿愈合裂隙分布；在成矿晚期的石英和方解石中主要发育原生H2O溶液包裹体。显微测温结果显示，成矿前（第1阶段）H2O-CO2包裹体的完全均一温度（Th,TOT，至液相）为254℃至365℃，成矿期（第Ⅱ和Ⅲ阶段）CO2-H2O±CH4包裹体的完全均一温度（Th，TOT，至液相）为195～317℃，成矿后（第Ⅳ阶段）H2O溶液包裹体的均一温度（Th,TOT；至液相）为156—219℃。成矿的初始流体富CO2，主成矿期有CH4流体加入，成矿晚期则演化为低温的水溶液流体。水／岩反应及流体不混溶可能是邓格庄金矿金沉淀的主要原因。 相似文献