天然沸石吸附性能与阳离子组分之间的关系   总被引：7，自引：0，他引：7  

张寿庭  赵鹏大  陈建平  徐旃章  郑明华 《地球化学》2001,30(5):477-482

吸附性能是沸石矿物的重要特性之一，也是相关领域应用的重要依据。以嫩江、海林和穆棱三大沸石矿床为例，通过对天然沸石矿的化学成分、沸石类型、矿石品位（CEC值）、比表面积及吸附性能的系统研究与对比分析，总结天然沸石矿附吸性能差异变化规律与原因。研究表明，天然沸石对气体CO2、H2S、SO2、NO2和气态H2O的吸附容量均与其（CaO MgO)/(Na2O K2O)比值之间呈正相关性关系，富二价阳离子组分者吸附容量大，富一价阳离子组分者吸附容量较小。据此，可作为天然沸石矿吸附性能预测评价的重要依据。  相似文献   

松辽盆地周围沸石矿成矿构造动力学环境   总被引：3，自引：0，他引：3  

张寿庭  赵鹏大  徐旃章  郑明华 《现代地质》2001,15(4):399-404

松辽盆地周围沸石资源丰富 ,矿床类型多样 ,是中国东部环太平洋沸石成矿带的重要组成部分。研究区NE—NNE向深大断裂带控制着中生代火山岩和沸石矿带的空间展布 ,而不同方向深大断裂带的交接复合地段则决定了沸石矿田和主要矿床的空间定位。燕山中晚期以挤压-剪切 (左行 )为主的构造动力学机制控制了富碱高钾火山岩的发育 ,为沸石矿源岩的形成期 ;喜山期的构造反转以拉张 -剪切 (右行 )为主的构造动力学机制及其相伴的岩浆热事件 ,导致区域地热异常、地下流体增温和沸石矿化作用的快速进行。研究区中生代火山岩系中沸石矿床的主成矿期为喜山期 (6 4 5～ 5 5 0Ma)。  相似文献   

Brazil's premier gold province. Part I: The tectonic, magmatic, and structural setting of the Archean Rio das Velhas greenstone belt, Quadrilátero Ferrífero     

Lydia Lobato  Luiz Ribeiro-Rodrigues  Márcia Zucchetti  Carlos Noce  Orivaldo Baltazar  Luiz da Silva  Claiton Pinto 《Mineralium Deposita》2001,36(3-4):228-248

  相似文献   

Gold distribution in lateritic profiles in South America, Africa, and Australia: applications to geochemical exploration in tropical regions     

Marcondes Lima da Costa   《Journal of Geochemical Exploration》1993,47(1-3)

Gold, a principal ore commodity, is sought in third world countries, which are situated mainly in the tropics, where extensive lateritic terrains exist. The high value of gold on the international market and balance of payment problems cause gold to be especially important. Present intensive propecting for gold in the Third World countries are, for those reasons, in lateritic terrains. Laterites, formed during the Tertiary and the Recent in inner tropical morphoclimatic zones covered by dense rain forests, in places such as the Amazon region and West Africa, are presently undergoing strong weathering and erosion that truncates lateritic profiles. Consequently, the thick soils still forming today cover in different places, different parts of truncated profiles. Samples of thick soils taken from the surface down, may begin not at the original top of the laterite but somewhere along the profile. Inasmuch as elements in lateritic profiles are not homogeneously distributed, problems in interpretation can result. Gold distribution in non-truncated laterites tends to be sigmoidal in distribution. Two convexities (highest contents) can be distinguished: one in surficial iron crusts or equivalents, the other at the base of saprolite. The sigmoidal curve can be cut off, strongly modified, or concealed by tropical weathering. The intense weathering can diminish concentrations, i.e., elements can be dispersed. Geochemical exploration becomes difficult, because interpretations of the geochemical anomalies based on high concentrations becomes unreliable. If the amount of truncation of lateritic profiles can be assessed, weak or even negative anomalies can become as good or better than strong anomalies.  相似文献   

Magnetotelluric measurements at Eusebio,an equatorial station     

N.B. Trivedi  Elesbão G. de Souza  Eurico R. de Paula  J.M. da Costa  Hugo Fournier 《Physics of the Earth and Planetary Interiors》1981,25(3):241-244

Magnetotelluric measurements in the period range 100–86400 s were conducted at a coastal station under the equatorial electrojet (Eusebio, 3.87°S, 321.58°E). The magnetotelluric data were hand-scaled and analysed to obtain a scalar apparent resistivity profile at Eusebio. The depth of the intermediate conducting layer was found to be in the range 45–75 km and the final conducting layer seems to begin at a depth of about 350 km. Possible effects of the source field equatorial electrojet are discussed and our results are compared with those of an African station under the equatorial electrojet.  相似文献   

First direct age determination from the Jurassic radiolarian-bearing siliceous series (Jédidi Formation) of northwestern Tunisia     

Fabrice Cordey  Mabrouk Boughdiri  Houaïda Sallouhi 《Comptes Rendus Geoscience》2005,337(8):777-785

Our study presents preliminary biostratigraphic results from the Jurassic siliceous series of northwestern Tunisia. For the first time, radiolarians are extracted from the Jédidi formation and provide a direct age determination. They are the first radiolarian fauna documented from Tunisia. Two age assignments are comprised within the following intervals: (1) Late Bathonian–Early Callovian, (2) Late Bathonian–Early Oxfordian. These ages are compatible with recent stratigraphic synthesis proposed for the Jurassic series of Tunisia. The data suggest the correlation of the Jédidi formation with siliceous series of Middle–Late Jurassic age from the external zone of the Maghrebides belt rather than with true oceanic units from the Maghrebian flyschs or the internal zones of western Tethys. To cite this article: F. Cordey et al., C. R. Geoscience 337 (2005).  相似文献   

Nomospace and genospace: A spatial matrix     

Paulo Cesar da Costa Gomes 《GeoJournal》2004,60(4):339-344

We are concerned here with the notion of space as a primary condition for building social relations. From this stand, we have created two analytical matrixes that can help us characterize two modes: that of ‘being-there-in-space’ and that of ‘being-of-the-space’; the nomospace and the genospace. While the nomospace is characterized by ‘cold’ connotations, which are ideally defined as a result of a logical option, the genospace is mainly characterized by emotional or ‘warm’ connotations, which originate from a feeling of shared nature and common destiny. We believe that these matrixes could help us to identify the meanings of some behaviours and, therefore, make us more capable of interpreting many dynamics that occur in modern societies. The importance of geography is justified by the existing relationship between these behaviours and their proper spatial form. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Temporal and spatial persistence in rainfall records from Northeast Brazil and Galicia (Spain)     

J. G. V. Miranda  R. F. S. Andrade  A. B. da Silva  C. S. Ferreira  A. P. Gonzalez  J. L. Carrera López 《Theoretical and Applied Climatology》2004,77(1-2):113-121

Summary Temporal and spatial persistence effects in historical rainfall records are investigated for a large number of stations from Northwest Spain (Galicia) and Northeast Brazil. Quantitative results, expressed by the Hurst or roughness exponent, are obtained by two methods: the R/S analysis and the semi-variogram. Despite rather different climatic conditions and period of analysis for the two regions, the results indicate that persistence and anti-persistence for the temporal and spatial analyses, respectively, are found for both regions. Temporal persistence is known to occur with other climatic fields and in many different regions of the world. Antipersistence in spatial patterns of rainfall is a strong result of this work, despite its apparent contradiction with temporal persistence. The results for Northeast Brazil support previous indications of a geographic stratification of persistence: both temporal and spatial persistence increase as latitude decreases.  相似文献   

Geochemical signatures and mechanisms of trace elements dispersion in the area of the Vale das Gatas mine (Northern Portugal)   总被引：2，自引：1，他引：2  

P. Freire vila  J.M. Santos Oliveira  E. Ferreira da Silva  E. Cardoso Fonseca 《Journal of Geochemical Exploration》2005,85(1):17-29

A geochemical survey involving the collection and analysis of 170 stream sediment samples was carried out in Vale das Gatas area in order to delineate geochemical signatures and to detect pollution hazards due to mining.Factor analysis applied to the data showed that the most important variables accounting for the first factor are Ag, Pb, Bi, As, W, Cd, Zn and Cu. These variables represent the most significant metalliferous elements of the original paragenesis, which still maintain a close relationship in the secondary geological environment. The spatial distribution of the factor scores referred to factor 1 indicates that positive scores occur predominantly in the Vale das Gatas and Sabrosa streams and in the main Pinhão river. The results also show that the Vale das Gatas mine is the most important contamination source in the Vale das Gatas district.In order to study the dispersion, transfer and uptake mechanisms of trace elements from the Vale das Gatas mine, additional sample media were collected, i.e., stream sediments, tailings, coatings, waters (surficial and mine waters) and specific biological species. Four sample stations were selected, namely two in connection with abandoned adits of the Vale das Gatas mine, one located in the Vale das Gatas stream and one located in the Pinhão River. The results show that chemical reactions of leaching and precipitation took place controlling the heavy metals in areas near the Vale das Gatas mine.At the same time, positive anomalous patterns are visible along the Pinhão river for about 20 km. The mineralogical composition of the stream sediments suggests that processes of mechanical dispersion also interfere in the secondary distribution of the metalliferous elements in that media.  相似文献   

The microscopic structure of the oxygen–aluminium hole center in natural and neutron irradiated blue topaz     

D.N. da Silva  K.J. Guedes  M.V.B. Pinheiro  J.M. Spaeth  K. Krambrock 《Physics and Chemistry of Minerals》2005,32(5-6):436-441

The dominant O⁻ hole center in natural and neutron irradiated blue topaz with general formula Al₂SiO₄(F,OH)₂ has been investigated with electron paramagnetic resonance (EPR) and optical absorption. The analysis of the EPR spectra of the O⁻ center yielded superhyperfine interactions with two equivalent Al neighbors in four magnetically inequivalent positions. From the g-factors it is found that the O⁻ hole center is located in (8d) Wyckoff positions on fluoride sites that were substituted by hydroxyl molecules prior to the irradiation. The spin Hamiltonian parameters were successfully interpreted with the model of transferred hyperfine interaction by exchange polarization supporting the localization of O⁻ in (F,OH)⁻ sites. The O⁻ center has the same thermal stability as the absorption band centered at 620 nm, which is responsible for the blue color. The intensity of the absorption band correlates linearly with the O⁻ concentration. Its correlation with the blue color is discussed.  相似文献