首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
喀喇沁橄榄石斑晶中流体包裹体的组分特征及其构造意义   总被引:8,自引:4,他引:4  
邵济安  王志海 《岩石学报》2000,16(2):275-280
利用激光拉曼光谱测定了内蒙古东部喀喇沁地区坡基橄岩橄榄石斑晶中的原生流体包裹体的成分,发现其主要由CO2、CO、H2O、N2、H2S、SO2、芳香族碳氢化合物及少量络阴离子团组成。本文认为,此火山岩的橄榄石斑晶中捕获的流体包裹体在一定程度上反映了地幔流体的成分。通过与河北汉诺坪地幔岩石捕虏体中的流体成分进行对比,认为华北克拉通中、新生代地幔流体成分变化不大,它们均形成于软流圈(层)上涌、岩石圈伸层  相似文献   

2.
赵令湖 《地球科学》1997,22(1):41-45
讨论了罗布莎铬铁矿床橄榄石的热力学条件和Ni质量分数等特征,总结出与矿化有关的三个热力学参数:平衡温度(t)、溶解热(ΔH)和密度(ρ),并且确定了其变化范围。探讨了该矿床的成因。研究结果表明,橄榄石的t-ΔH-ρ在铬铁矿成矿预测中作为矿物学标型参数来圈定矿体的远景区已基本上满足了勘探和开采的要求。  相似文献   

3.
讨论了罗布莎铬铁矿床橄榄石的热力学条件和Ni质量分数等待征,总结出与矿化有关的三个热力学参数:平衡温度(t)、溶解热(△H)和密度(p)。并且确定了其变化范围。探讨了该矿床的成因。研究结果表明,橄榄石的t-△H-p在铬铁矿成矿预测中作为矿物学标型参数来圈定矿体的远景区已基本上满足了勘探和开采的要求。  相似文献   

4.
方解石—橄榄石—流体三相体系氧同位素交换的实验研究   总被引:2,自引:2,他引:0  
郑永飞 Satir  M 《地球化学》1999,28(5):411-420
在680℃和500MPa以及岩石学相平衡条件下,首次对方解石与镁橄榄石之间在大量超临界CO2-H2O流体存在的条件下进行了氧同位素交换实验。结果发现,在实验刚刚开始的一段时间内氧同位素交换很快,主要是以溶解/重结晶的机制进行的;而在以后的时间里氧同位素交换要慢得多,变成以扩散机制为主。进一步,反应产物方解石相对于镁橄榄石亏损^18O,指示方解石的溶解/重结晶速率大于镁橄榄石。流体相的存在导致具有不  相似文献   

5.
土壤中的易溶盐,如Na2SO4·10H2O、MgSO4·7H2O等,吸水时体积膨胀,失水时体积收缩。这些易溶盐蕴含在地基土中将直接影响其膨缩。本文叙述了测定SO的原理和方法,将给地基的设防提供可靠的依据。  相似文献   

6.
傅平秋  李哲 《矿物学报》1996,16(2):147-151
本文使用穆斯堡尔效应研究了在高温高压下合成的铁橄榄石和铁尖晶橄榄石。298K温度下铁橄榄石的穆斯堡尔谱由一组双峰组成,它被指派给Fe^2+(M1,M2)离子。298K温度下铁尖晶橄榄石的穆斯堡尔谱由三组双峰组成,其中两组双峰指派给八面体位置B上的Fe^2+,另一组双峰归为四面体位置A上的Fe^3+,两组Fe^2+双峰的同质异能迁移近似相等而四极分裂不同,Si原子在八面体位置上的占有率为6%~10%  相似文献   

7.
唐春花  楼法生 《江西地质》1999,13(3):172-175
永修一南昌剪切带中糜棱岩物质成分变异及体积变化分析结果表明,以Al2O3守恒为限制条件,该剪切带损失了9%的质量和体积,糜棱岩类Fe2O3明显带入了SiO2,K2,MgO,P2O5,FeO,Na2O等组分明显带出,研究结果显示糜棱岩组分的得失和体积的变化主要发生在初糜棱岩化阶段。  相似文献   

8.
陆源碎屑沉积作用对化学元素配分的制约   总被引:4,自引:2,他引:4  
杨忠芳  陈岳龙 《地质论评》1997,43(6):593-600
为探讨粒度分选沉积作用对沉积物化学成分配分的影响,对比研究了五台群中石英型,长石石英岩,粉砂岩和粘土岩等不同粒度沉积岩的化学成分特征,结果表明:不同粒度沉积岩的主元素及微量元素均具有较大的变化范围,SiO2与Al2O3及TFe2O3之间呈线性负相关关系,这种负相关关系还表现在SiO2与REE,Rb,Se之间,这种特征可以用石英的稀释作用进行解释.  相似文献   

9.
蛇纹石化碱性橄榄石玄武岩、水和氢氧化钠溶液的高温高压实验研究宋茂双(中国科学院地球化学研究所,贵阳550002)关键词高温高压碱性玄武岩P波速度熔融-结晶蛇纹石脱水温度作者测量了高温高压下蛇纹石化碱性橄榄玄武岩的P波速度、蛇纹石脱水温度和H2O及Na...  相似文献   

10.
室温条件下微生物环境中块金生长机理的实验研究   总被引:6,自引:1,他引:5  
张海祥  阚小凤 《地球化学》1999,28(2):177-182
室温条件下,用真菌、硅藻、固氮菌及芽孢杆菌等不同微生物,经3个月至18个月的时间,可将砖红色的海绵金培育成片状、丝状及粒状的Au颗粒,这表明在表生条件及微生物环境中,Au可以被活化、迁移、再生长、测定结果表明,培养液中的Au质量浓度与其中的H2O2质量浓度有正相关关系;而且,Au和H2O2质量浓度高的样品,其中的金粒生长速率也快,说明表生条件下块金的生长与溶液中的H2O2质量浓度密切相关。  相似文献   

11.
The D/H ratios of separated size fractions of clay minerals in two deep sea sediments taken from depths of 30 and 1100cm in a North Pacific Ocean core were measured to investigate the extent of hydrogen isotope exchange between detrital clay minerals and sea water. The D/H ratio of each size fraction of the shallower sample was compared with that of the corresponding size fraction of the deeper sample. No differences were detected between D/H ratios of corresponding size fractions from the two levels in the core except for the <0.1μm size fraction, which makes up only 5% of the sample. Even in this size fraction only about 8–28% D/H exchange is apparent. This is interpreted as indicating that no significant hydrogen isotope exchange between clay minerals and sea water has occurred during the past 2–3 Myr. Therefore information concerning the provenance and mode of formation of detrital clay minerals can be obtained from the D/H ratios of deep sea sediments younger than 2–3 Myr.  相似文献   

12.
金刚石中的氢及其在金刚石高温高压合成中的意义   总被引:1,自引:0,他引:1  
氢在金刚石中往往以一定的化学态形式存在,不同类型的金刚石中氢会以不同的电荷状态进行迁移与扩散,也可以与其他杂质元素N、B、P等作用,形成(N,H)、(B,H)、(P,H)对;为高温高压合成金刚石的物质体系中引入氢,有利于提高高温高压合成金刚石的产量、粒度及品级,也将为模拟天然金刚石的形成与探讨地球深部的动力学过程提供科学线索。  相似文献   

13.
Removal of hydrogen sulfide by zinc oxide nanoparticles in drilling fluid   总被引:1,自引:0,他引:1  
Hydrogen sulfide is a very dangerous, toxic and corrosive gas. It can diffuse into drilling fluid from formations during drilling of gas and oil wells. Hydrogen sulfide should be removed from this fluid to reduce the environmental pollution, protect the health of drilling workers and prevent corrosion of pipelines and equipments. In this research nano zinc oxide with 14–25 nm particle size and 44–56 m2/g specific surface area was synthesized by spray pyrolysis method. The synthesized nanoparticles were used to remove hydrogen sulfide from water based drilling fluid. The efficiency of these nanoparticles in the removal of hydrogen sulfide from drilling mud were evaluated and compared with that of bulk zinc oxide. The obtained results show that synthesized zinc oxide nanoparticles are completely able to remove hydrogen sulfide from water based drilling mud in just 15 min., whereas bulk zinc oxide is able to remove 2.5% of hydrogen sulfide in as long as 90 min. under the same operating conditions.  相似文献   

14.

Background

Hydrogen is known to occur in the groundwaters of some ancient cratons. Where associated gases have been dated, their age extends up to a billion years, and the hydrogen is assumed also to be very old. These observations are interpreted to represent the radiolysis of water and hydration reactions and migration of hydrogen into fracture systems. A hitherto untested implication is that the overwhelming bulk of the ancient low-permeability basement, which is not adjacent to cross-cutting fractures, constitutes a reservoir for hydrogen.

Results

New data obtained from cold crushing to liberate volatiles from fluid inclusions confirm that granites and gneiss of Archean and Palaeoproterozoic (>1600 Ma) age typically contain an order of magnitude greater hydrogen in their entrained fluid than very young (<200 Ma) granites. Sedimentary rocks containing clasts of old basement also include a greater proportion of hydrogen than the young granites.

Conclusions

The data support the case for a global reservoir of hydrogen in both the ancient basement and in the extensive derived sediments. These reservoirs are susceptible to the release of hydrogen through a variety of mechanisms, including deformation, attrition to reduce grain size and diagenetic alteration, thereby contributing to the hydrogen required by chemolithoautotrophs in the deep biosphere.
  相似文献   

15.
This paper examines the active mechanisms responsible for the size enlargement of nickel metal particles during reduction by hydrogen gas. The population balance, related to particle size distribution, is discretized and solved with the method of moments to model the experimental data. This data was generated in a solution of intermittently constant supersaturation during the batch reduction in an 11,000 l of autoclave. PSD and mass distributions were determined by periodically removing suspension samples. In the proposed model, only the growth mechanism is taken into account and aggregation is ignored. Comparison of simulated and experimental PSD and mass distributions show that growth was not the only active mechanisms. Results from the plant indicate that there is an increase in particle size as the cycle progresses. The model generally underpredicts the growth shift in the PSDs' for the early and the larger densifications although it correctly predicts the growth shift in the middle densifications. Constant growth is therefore not the exclusive controlling mechanism. The findings have been confirmed by the trend of the zeroth moment as a function of time.  相似文献   

16.
Electro-flotation tests were conducted on chalcopyrite particles with a modified Hallimond tube designed for electro-flotation, using platinum anode—copper cathode and graphite anode—copper cathode systems. Flotation tests were carried out for fines of chalcopyrite of size below 20 microns with potassium ethylxanthate as collector. Studies were done on flotation with hydrogen and oxygen separately with the usual variables. Dissolution of chalcopyrite at various current densities, with reagent at optimum conditions and without reagent was also studied. It is observed that electro-flotation particularly with oxygen, is effective in the flotation of fine particles of chalcopyrite.  相似文献   

17.
Proton conduction in olivine is directly related to the diffusion rate of hydrogen by the Nernst–Einstein equation, but prior attempts to use this relationship have always invoked additional terms to try to reconcile laboratory measurements of proton conduction and hydrogen diffusion data. New diffusion experiments on olivine demonstrate that lattice diffusion associated with vacancies is indeed highly dependent on the defect site where hydrogen is bonded, but from none of the sites is diffusion fast enough to explain the observed laboratory proton conduction experiments. Hydrogen diffusion associated with polarons (redox-exchange) is significantly faster but still cannot explain the low activation energy typical of electrical conductivity measurements. A process of bulk diffusion, which combines lattice diffusion (either associated with redox-exchange or vacancies) with the far faster grain boundary diffusion, explains the laboratory results, but does not explain the field observations with an average grain size of 0.5–2 cm at 100 km below the Jagersfontein kimberlite field on the Kaapvaal craton. Either conduction is dominantly along well-interconnected grain boundaries of very fine-grained (0.01 mm) damp (80 wt ppm) olivine grains or fine-grained (0.05 mm), wet (400 wt ppm) pyroxene grains, or another conduction mechanism must be primarily responsible for the field observations. If diffusion is the correct explanation, the conductivity below the Gibeon kimberlite field in Namibia is too high to be explained by increased thermal state alone of a diffusion process, even for such fine-grained pyroxenes.  相似文献   

18.
A model describing the main processes determining the evolution of hydrocarbon dust grains of arbitrary size under astrophysical conditions corresponding to regions of ionized hydrogen (HII regions) and supernova remnants is presented. The processes considered include aromatization and photodestruction, sputtering by electrons and ions, and shattering during collisions between grains. The model can be used to calculate the size distribution of the grains and the degree of aromatization during the evolution of HII regions and supernova remnants for a specified radiation field, relative velocity between the gas and dust, etc. The contribution of various processes to the evolution of hydrocarbon dust grains for parameters typical for the interstellar medium of our Galaxy is considered. Small grains (with fewer than 50 carbon atoms) should be fully aromatized in the interstellar medium. If larger grains initially have an aliphatic structure, this is preserved to a substantial extent. Variation in the size distribution of the grains due to collisions between grains depend appreciably on the adopted initial size distribution. With an initial distribution corresponding to that of Mathis et al. (1977), the mass fraction contributed by smaller grains tends to increase with time, while, with an initial distribution corresponding to that of Jones et al. (2013), in which the fraction of small grains is initially high, there is a general decrease in the number of grains of various sizes with time.  相似文献   

19.
在热带砂质海岸,生物碎屑是海滩沉积物的重要组成部分,其分布和变化影响海滩沉积物的粒度特征。采用添加过量盐酸和双氧水的方法对海南高隆湾海滩表层沉积物进行了去生物碎屑前后粒径分布的对比,并结合海滩高程测量分析,结果表明:(1)海滩剖面上沉积物中生物碎屑的含量主要受到海水动力的影响,且生物碎屑颗粒较粗、重量较大,在高潮时由波浪流推上海滩并滞留。(2)海滩沉积物中生物碎屑的分布主要受三方面影响:一是地形及常涌浪向;二是区域中养殖业产生的生物碎屑;三是岸外发育的珊瑚礁坪。(3)海滩沉积物中生物碎屑的含量随季节变化,冬季至春季由海水供给的生物碎屑减少、进一步分解,使得北部海滩生物碎屑含量减少;而珊瑚碎屑的稳定供给和春季较强的波浪动力条件又使研究区南部断面的生物碎屑含量增加。(4)海滩沉积物中粗颗粒所含生物碎屑多于细颗粒中的生物碎屑,生物碎屑粒径主要为-1~2,即粗砂至细砾。沉积物中生物碎屑含量愈大,对粒径参数的影响也愈大。  相似文献   

20.
Raman spectra of natural analcime have been recorded at atmospheric pressure and up to 9.4 kbar. The basic Si, Al-O network vibrations are little affected by pressure even though significant volume changes and a minor phase transition take place. However, the 3,557 cm?1 OH-stretch mode is modified in that band splitting takes place indicating at least two O-OH hydrogen bond distances. Thus there are at least three sites of hydrogen bonding in analcime. The bonded water (H2O) in analcime appears to remain in the mineral at high pressure. The bulk volume change, determined previously by cell dimension measurements, can be traced to reduction of the size of the “voids” in the structure. This is deduced from the fact that Si-Al-O vibrations are little affected by pressure but O-H vibrations of water molecules found in the voids are strongly pressure-dependent.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号