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Sample records for stromboli basaltic glasses

  1. A CO 2-rich gas trigger of explosive paroxysms at Stromboli basaltic volcano, Italy

    Science.gov (United States)

    Allard, Patrick

    2010-01-01

    In addition to rhythmic slug-driven Strombolian activity, Stromboli volcano occasionally produces discrete explosive paroxysms (2 per year on average for the most frequent ones) that constitute a major hazard and whose origin remains poorly elucidated. Partial extrusion of the volatile-rich feeding basalt as aphyric pumice during these events has led to consider their triggering by the fast ascent of primitive magma blobs from possibly great depth. Here I examine and discuss the alternative hypothesis that most of the paroxysms could be triggered and driven by the fast upraise of CO 2-rich gas pockets generated by bubble foam growth and collapse in the sub-volcano plumbing system. Data for the SO 2 and CO 2 crater plume emissions are used to show that Stromboli's feeding magma may originally contain as much as 2 wt.% of carbon dioxide and early coexists with an abundant CO 2-rich gas phase with high CO 2/SO 2 molar ratio (≥ 60 at 10 km depth below the vents, compared to ˜ 7 in time-averaged crater emissions). Pressure-related modelling indicates that the time-averaged crater gas composition and output are well accounted for by closed system decompression of the basalt-gas mixture until the volcano-crust interface (˜ 3 km depth), followed by open degassing and crystallization in the volcano conduits. However, both the low viscosity and high vesicularity of the basaltic magma permit bubble segregation and bubble foam growth at deep sill-like feeder discontinuities and at shallower physical boundaries (such as the volcano-crust interface) where the gas-rich aphyric basalt interacts with the unerupted crystal-rich and viscous magma drained back from the volcano conduits. Gas pressure build-up and bubble foam collapse at these boundaries will intermittently trigger the sudden upraise of CO 2-rich gas blobs that constitute the main driving force of the paroxysms. Deeper-sourced gas blobs, driving the most powerful explosions, will be the richest in CO 2 and have

  2. Temperature evolution during magma ascent in basaltic effusive eruptions: A numerical application to Stromboli volcano

    Science.gov (United States)

    La Spina, G.; Burton, M.; de'Michieli Vitturi, M.

    2015-09-01

    The dynamics of magma ascent are controlled by the complex, interdependent processes of crystallisation, rheological evolution, gas exsolution, outgassing, non-ideal gas expansion and temperature evolution. Temperature changes within the conduit, in particular, play a key role on ascent dynamics, since temperature strongly controls the crystallisation process, which in turn has an impact on viscosity and thus on magma ascent rate. The cooling produced by gas expansion is opposed by the heat produced by crystallisation, and therefore the temperature profile within the conduit is quite complex. This complexity means that unravelling the dynamics controlling magma ascent requires a numerical model. Unfortunately, comprehensive, integrated models with full thermodynamic treatment of multiple phases and rheological evolution are challenging to produce, due to the numerical challenges involved. Until now, models have tended to focus on aspects of the problem, without a holistic approach in which petrological, thermodynamic, rheological and degassing processes, and their interactions, were all explicitly addressed and quantified. Here, we present a new, multiphase steady-state model for magma ascent in which the main physical and chemical processes, such as crystallisation, degassing, outgassing, rheological evolution and temperature variations, are quantitatively calculated. Basaltic magma's crystallisation and flow are sensitive to initial temperature and volatile content, and therefore we investigate temperature variations during magma ascent in a basaltic system with a range of volatile contents. As a test case, we use one of the most well-studied recent basaltic effusive eruptions: the 2007 eruption of Stromboli, Italy. Assuming equilibrium crystallisation and exsolution, we compare the solutions obtained both with and without an isothermal constraint, finding that temperature variations within the conduit have a significant influence on the ascent dynamics and

  3. Time-dependent deformation at elevated temperatures in basalt from El Hierro, Stromboli and Teide volcanoes

    Science.gov (United States)

    Benson, P. M.; Fahrner, D.; Harnett, C. E.; Fazio, M.

    2014-12-01

    Time dependent deformation describes the process whereby brittle materials deform at a stress level below their short-term material strength (Ss), but over an extended time frame. Although generally well understood in engineering (where it is known as static fatigue or "creep"), knowledge of how rocks creep and fail has wide ramifications in areas as diverse as mine tunnel supports and the long term stability of critically loaded rock slopes. A particular hazard relates to the instability of volcano flanks. A large number of flank collapses are known such as Stromboli (Aeolian islands), Teide, and El Hierro (Canary Islands). Collapses on volcanic islands are especially complex as they necessarily involve the combination of active tectonics, heat, and fluids. Not only does the volcanic system generate stresses that reach close to the failure strength of the rocks involved, but when combined with active pore fluid the process of stress corrosion allows the rock mass to deform and creep at stresses far lower than Ss. Despite the obvious geological hazard that edifice failure poses, the phenomenon of creep in volcanic rocks at elevated temperatures has yet to be thoroughly investigated in a well controlled laboratory setting. We present new data using rocks taken from Stromboli, El Heirro and Teide volcanoes in order to better understand the interplay between the fundamental rock mechanics of these basalts and the effects of elevated temperature fluids (activating stress corrosion mechanisms). Experiments were conducted over short (30-60 minute) and long (8-10 hour) time scales. For this, we use the method of Heap et al., (2011) to impose a constant stress (creep) domain deformation monitored via non-contact axial displacement transducers. This is achieved via a conventional triaxial cell to impose shallow conditions of pressure (<25 MPa) and temperature (<200 °C), and equipped with a 3D laboratory seismicity array (known as acoustic emission, AE) to monitor the micro

  4. Hardness of basaltic glass-ceramics

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Estrup, Maja

    2009-01-01

    The dependence of the hardness of basaltic glass-ceramics on their degree of crystallisation has been explored by means of differential scanning calorimetry, optical microscopy, x-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses were achieved...... by varying the temperature of heat treatment. The predominant crystalline phase in the glass was identified as augite. It was found that the hardness of the glass phase decreased slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreased....

  5. Structural relaxation in annealed hyperquenched basaltic glasses

    DEFF Research Database (Denmark)

    Guo, Xiaoju; Mauro, John C.; Potuzak, M.

    2012-01-01

    The enthalpy relaxation behavior of hyperquenched (HQ) and annealed hyperquenched (AHQ) basaltic glass is investigated through calorimetric measurements. The results reveal a common onset temperature of the glass transition for all the HQ and AHQ glasses under study, indicating that the primary...... relaxation is activated at the same temperature regardless of the initial departure from equilibrium. The analysis of secondary relaxation at different annealing temperatures provides insights into the enthalpy recovery of HQ glasses....

  6. Study of crystallization of a basalt glass

    International Nuclear Information System (INIS)

    Nishimura, Fernando Takahiro; Hashizume, Camila Mina; Toffoli, Samuel Marcio

    2009-01-01

    Basalt vitreous ceramics posses industrial importance by presenting high mechanical resistance to the abrasion. It was studied the obtention and the crystallization of a glass obtained from a basalt of Campinas, Sao Paulo, Brazil, aiming to develop a material with great abrasive resistance. Fusions were made at 1400 deg Celsius in electrical oven and in alumina crucible, of fine residues of basalt mining. The obtained glass was treated in a crystallization temperature of 880 deg Celsius, determined by DSC, by various time of treatment. The present main crystalline phases, detected by XRD, were the magnesium-ferrite (MgFe 2 O 4 ) and the diopsid Ca(Mg,Fe,Al)(Si,Al) 2 O 6 . Analysing the density by the Archimedes methodology and the DRX it was possible to follow the crystallization kinetic up.

  7. SEM-based methods for the analysis of basaltic ash from weak explosive activity at Etna in 2006 and the 2007 eruptive crisis at Stromboli

    Science.gov (United States)

    Lautze, Nicole C.; Taddeucci, Jacopo; Andronico, Daniele; Cannata, Chiara; Tornetta, Lauretta; Scarlato, Piergiorgio; Houghton, Bruce; Lo Castro, Maria Deborah

    2012-01-01

    We present results from a semi-automated field-emission scanning electron microscope investigation of basaltic ash from a variety of eruptive processes that occurred at Mount Etna volcano in 2006 and at Stromboli volcano in 2007. From a methodological perspective, the proposed techniques provide relatively fast (about 4 h per sample) information on the size distribution, morphology, and surface chemistry of several hundred ash particles. Particle morphology is characterized by compactness and elongation parameters, and surface chemistry data are shown using ternary plots of the relative abundance of several key elements. The obtained size distributions match well those obtained by an independent technique. The surface chemistry data efficiently characterize the chemical composition, type and abundance of crystals, and dominant alteration phases in the ash samples. From a volcanological perspective, the analyzed samples cover a wide spectrum of relatively minor ash-forming eruptive activity, including weak Hawaiian fountaining at Etna, and lava-sea water interaction, weak Strombolian explosions, vent clearing activity, and a paroxysm during the 2007 eruptive crisis at Stromboli. This study outlines subtle chemical and morphological differences in the ash deposited at different locations during the Etna event, and variable alteration patterns in the surface chemistry of the Stromboli samples specific to each eruptive activity. Overall, we show this method to be effective in quantifying the main features of volcanic ash particles from the relatively weak - and yet frequent - explosive activity occurring at basaltic volcanoes.

  8. Viscoelastic behavior of basaltic ash from Stromboli volcano inferred from intermittent compression experiments

    Science.gov (United States)

    Kurokawa, A. K.; Miwa, T.; Okumura, S.; Uesugi, K.

    2017-12-01

    After ash-dominated Strombolian eruption, considerable amount of ash falls back to the volcanic conduit forming a dense near-surface region compacted by weights of its own and other fallback clasts (Patrick et al., 2007). Gas accumulation below this dense cap causes a substantial increase in pressure within the conduit, causing the volcanic activity to shift to the preliminary stages of a forthcoming eruption (Del Bello et al., 2015). Under such conditions, rheology of the fallback ash plays an important role because it controls whether the fallback ash can be the cap. However, little attention has been given to the point. We examined the rheology of ash collected at Stromboli volcano via intermittent compression experiments changing temperature and compression time/rate. The ash deformed at a constant rate during compression process, and then it was compressed without any deformation during rest process. The compression and rest processes repeated during each experiment to see rheological variations with progression of compaction. Viscoelastic changes during the experiment were estimated by Maxwell model. The results show that both elasticity and viscosity increases with decreasing porosity. On the other hand, the elasticity shows strong rate-dependence in the both compression and rest processes while the viscosity dominantly depends on the temperature, although the compression rate also affects the viscosity in the case of the compression process. Thus, the ash behaves either elastically or viscously depending on experimental process, temperature, and compression rate/time. The viscoelastic characteristics can be explained by magnitude relationships between the characteristic relaxation times and times for compression and rest processes. This indicates that the balance of the time scales is key to determining the rheological characteristics and whether the ash behaves elastically or viscously may control cyclic Strombolian eruptions.

  9. Transient processes in Stromboli's shallow basaltic system inferred from dolerite and magmatic breccia blocks erupted during the 5 April 2003 paroxysm

    Science.gov (United States)

    Renzulli, Alberto; Del Moro, Stefano; Menna, Michele; Landi, Patrizia; Piermattei, Marco

    2009-09-01

    We describe the mineralogy, geochemistry, and mesomicrostructure of fresh subvolcanic blocks erupted during the 5 April 2003 paroxysm of Stromboli (Aeolian Islands, Italy). These blocks represent ˜50 vol.% of the total erupted ejecta and consist of fine- to medium-grained basaltic lithotypes ranging from relatively homogeneous dolerites to strongly or poorly welded magmatic breccias. The breccia components are represented by angular fragments of dolerites entrapped in a matrix of vesiculated (lava-like to scoriae) crystal-rich (CR) basalt. All of the studied blocks are cognates with the CR basalt of the normal Strombolian activity or lavas and they are often coated by a few-centimeter thick layer of crystal-poor (CP) basaltic pumice erupted during the paroxysm. We suggest that they result from the rapid increase of pressure and related subvolcanic rock failure that occurred shortly before the 5 April 2003 explosion, when the uppermost portion of the edifice inflated and suffered brecciation as the result of the sudden rise of the gas-rich CP basalt that triggered the eruption. Dolerites and magmatic matrix of the breccias show major and trace element compositions that match those of the CR basalts erupted during normal Strombolian activity and effusive events at Stromboli volcano. Dolerites consist of (a) phenocrysts normally found in the CR basalts and (b) late-stage magmatic minerals such as sanidine, An60-28 plagioclase, Fe-Mn-rich olivines (Fo68-48), phlogopite, apatite, and opaque mineral pairs (magnetite and ilmenite), most of which are never found both in lava flows and scoriae erupted during the persistent explosive activity that characterizes typical Strombolian behavior. Subvolcanic crystallization of the Stromboli CR magma, leading to slowly cooled equivalents of basalts, could result from transient drainage of the magma from the summit craters to lower levels. Fingering and engulfing of the material that collapsed from the summit crater floor into the

  10. Behaviour of rare earth elements, as natural analogues of transuranium elements, during weathering of basaltic glasses

    International Nuclear Information System (INIS)

    Daux, V.; Crovisier, J.L.; Petit, J.C.

    1991-01-01

    Subglacial basaltic glasses from Iceland have been studied in order to investigate REE behaviour low-temperature weathering. Just as actinides accumulate in the hydrated superficial corrosion layer of borosilicate glasses, REEs are found to be enriched in the natural corrosion layer of basaltic glasses (palagonite). However, this enrichment is only relative for basaltic glasses [fr

  11. Dissolution of basaltic glass in seawater: Mechanism and rate

    International Nuclear Information System (INIS)

    Crovisier, J.L.; Honnorez, J.; Eberhart, J.P.

    1987-01-01

    Basaltic glasses are considered as natural analogues for nuclear waste glasses. Thermodynamic computer codes used to evaluate long term behavior of both nuclear waste and basaltic glasses require the knowledge of the dissolution mechanism of the glass network. The paper presents the results of a series of experiments designed to study the structure and chemical composition of alteration layers formed on the surface of artificial tholeiitic glass altered in artificial seawater. Experiments were performed at 60 degree C, 1 bar and 350 bars in non-renewed conditions. A natural sample from Palagonia (Sicily) has been studied by electron microscopy and comparison between natural and experimental palagonitic layers is made. The behavior of dissolved silica during experiments, and both the structure and the chemical composition of the palagonitic layers, indicate that they form by precipitation of secondary minerals from solution after a total breakdown of the glassy network, i.e., congruent dissolution of the glass. Hence the dissolution equation necessary for thermodynamic modelling of basaltic glass dissolution in seawater at low temperature must be written as a simple stoichiometric process. These experiments indicate that the transformation of glass to palagonitic material is not isovolumetric. Hence it is preferable to use Fe or Ti as conservative elements for chemical budget calculations

  12. Alteration of basaltic glasses from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    chemical changes are the loss of Si, Mg and Ca and a gain of Na and K whilst, Fe and Ti remained immobile. It reflects that the basaltic glasses have undergone initial to intermediate stages of palagonitisation under low temperature oxidative alterations...

  13. A new basaltic glass microanalytical reference material for multiple techniques

    Science.gov (United States)

    Wilson, Steve; Koenig, Alan; Lowers, Heather

    2012-01-01

    The U.S. Geological Survey (USGS) has been producing reference materials since the 1950s. Over 50 materials have been developed to cover bulk rock, sediment, and soils for the geological community. These materials are used globally in geochemistry, environmental, and analytical laboratories that perform bulk chemistry and/or microanalysis for instrument calibration and quality assurance testing. To answer the growing demand for higher spatial resolution and sensitivity, there is a need to create a new generation of microanalytical reference materials suitable for a variety of techniques, such as scanning electron microscopy/X-ray spectrometry (SEM/EDS), electron probe microanalysis (EPMA), laser ablation inductively coupled mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). As such, the microanalytical reference material (MRM) needs to be stable under the beam, be homogeneous at scales of better than 10–25 micrometers for the major to ultra-trace element level, and contain all of the analytes (elements or isotopes) of interest. Previous development of basaltic glasses intended for LA-ICP-MS has resulted in a synthetic basaltic matrix series of glasses (USGS GS-series) and a natural basalt series of glasses (BCR-1G, BHVO-2G, and NKT-1G). These materials have been useful for the LA-ICP-MS community but were not originally intended for use by the electron or ion beam community. A material developed from start to finish with intended use in multiple microanalytical instruments would be useful for inter-laboratory and inter-instrument platform comparisons. This article summarizes the experiments undertaken to produce a basalt glass reference material suitable for distribution as a multiple-technique round robin material. The goal of the analytical work presented here is to demonstrate that the elemental homogeneity of the new glass is acceptable for its use as a reference material. Because the round robin exercise is still underway, only

  14. Basaltic glass alteration in confined media: analogy with nuclear glass in geological disposal conditions

    International Nuclear Information System (INIS)

    Parruzot, Benjamin

    2014-01-01

    This dissertation concerns basaltic glass alteration mechanisms and rates. Through a better understanding of the processes controlling the basaltic glass durability, this thesis attempts to establish a link between laboratory studies and volcanic glass alteration in natural environment. The methodology used here is similar to the one used for nuclear glasses. Thus, we measured for the first time the residual alteration rate of basaltic glasses. Protective effect of the alteration film is clearly established. Moreover, synthetic glass representativeness is evaluated through a study focused on the effect of iron oxidation degree on the glass structure and leaching properties. A minor effect of Fe II on the forward rate and a negligible effect on the residual rate are shown. The residual rate is extrapolated at 5 C and compared to the mean alteration rate of natural samples of ages ranging from 1900 to 10 7 years. Non-zeolitized natural glasses follow this linear tendency, suggesting a control of the long-term rate by clayey secondary phase precipitation. Natural environments are open environments: a parametric study was performed in order to quantify the water flow rate effect on chemical composition of the alteration layer. When applied to two natural samples, the obtained laws provide coherent results. It seems possible to unify the descriptive approach from the study of natural environments to the mechanistic approach developed at the laboratory. The next step will consist in developing a model to transpose these results to nuclear glasses. (author) [fr

  15. Long-term alteration of basaltic glass: Mechanisms and rates

    Science.gov (United States)

    Parruzot, Benjamin; Jollivet, Patrick; Rébiscoul, Diane; Gin, Stéphane

    2015-04-01

    The long-term behavior study of archaeological artifacts and natural minerals and glasses revealed discrepancies between laboratory and field data. For a better understanding of the cause of these discrepancies and to reinforce the use of basaltic glass as an analog for nuclear waste glasses, this study focuses on the determination of alteration rates and processes of synthetic basaltic glass in residual rate regime. Laboratory batch experiments were performed at high surface-to-volume ratios at 90 and 30 °C for more than 1000 days. In all the experiments, the residual rate regime was reached after about 6 months. The residual alteration rates at 30 and 90 °C were 4.0 ± 1.0 × 10-6 and 9.5 ± 3.2 × 10-6 g·m-2·d-1, respectively. At 90 °C, this residual alteration rate is five orders of magnitude lower than the forward alteration rate (0.8 g·m-2·d-1). Altered powders and monoliths were characterized by Transmission Electron Microscopy and Time-of-Flight Secondary Ion Mass Spectrometry. From glass core to solution, the altered materials are structured as follows: pristine glass, gel (corresponding to the palagonitic layer of natural glasses) and intergranular clays. To assess the passivating properties of this alteration film, we used solid characterization, an isotopically-tagged post-leaching experiment and the measurement of mobile species diffusion coefficients through the alteration film at different stages of reaction using various techniques (solution analysis and X-ray Reflectometry). These characterizations showed that the alteration film formed during residual rate alteration is passivating even without clogged porosity within the gel. Diffusion coefficients of water and alkali metals - respectively diffusing to and from the pristine glass - through the alteration film dropped from 10-20 to 10-19 m2·s-1 during the first alteration stages to 10-25 m2·s-1 in residual rate regime.

  16. Potential for microbial oxidation of ferrous iron in basaltic glass.

    Science.gov (United States)

    Xiong, Mai Yia; Shelobolina, Evgenya S; Roden, Eric E

    2015-05-01

    Basaltic glass (BG) is an amorphous ferrous iron [Fe(II)]-containing material present in basaltic rocks, which are abundant on rocky planets such as Earth and Mars. Previous research has suggested that Fe(II) in BG can serve as an energy source for chemolithotrophic microbial metabolism, which has important ramifications for potential past and present microbial life on Mars. However, to date there has been no direct demonstration of microbially catalyzed oxidation of Fe(II) in BG. In this study, three different culture systems were used to investigate the potential for microbial oxidation of Fe(II) in BG, including (1) the chemolithoautotrophic Fe(II)-oxidizing, nitrate-reducing "Straub culture"; (2) the mixotrophic Fe(II)-oxidizing, nitrate-reducing organism Desulfitobacterium frappieri strain G2; and (3) indigenous microorganisms from a streambed Fe seep in Wisconsin. The BG employed consisted of clay and silt-sized particles of freshly quenched lava from the TEB flow in Kilauea, Hawaii. Soluble Fe(II) or chemically reduced NAu-2 smectite (RS) were employed as positive controls to verify Fe(II) oxidation activity in the culture systems. All three systems demonstrated oxidation of soluble Fe(II) and/or structural Fe(II) in RS, whereas no oxidation of Fe(II) in BG material was observed. The inability of the Straub culture to oxidize Fe(II) in BG was particularly surprising, as this culture can oxidize other insoluble Fe(II)-bearing minerals such as biotite, magnetite, and siderite. Although the reason for the resistance of the BG toward enzymatic oxidation remains unknown, it seems possible that the absence of distinct crystal faces or edge sites in the amorphous glass renders the material resistant to such attack. These findings have implications with regard to the idea that Fe(II)-Si-rich phases in basalt rocks could provide a basis for chemolithotrophic microbial life on Mars, specifically in neutral-pH environments where acid-promoted mineral dissolution and

  17. The 2007 and 2014 eruptions of Stromboli at match: monitoring the potential occurrence of effusion-driven basaltic paroxysmal explosions from a volcanic CO2 flux perspective

    Science.gov (United States)

    Liuzzo, Marco; Aiuppa, Alessandro; Salerno, Giuseppe; Burton, Mike; Federico, Cinzia; Caltabiano, Tommaso; Giudice, Gaetano; Giuffrida, Giovanni

    2015-04-01

    The recent effusive unrests of Stromboli occurred in 2002 and 2007 were both punctuated by short-lived, violent paroxysmal explosions generated from the volcano's summit craters. When effusive activity recently resumed on Stromboli, on 6 August 2014, much concern was raised therefore on whether or not a paroxysm would have occurred again. The occurrence of these potentially hazardous events has stimulated research toward understanding the mechanisms through which effusive eruptions can perturb the volcano's plumbing system, to eventually trigger a paroxysm. The anomalously large CO2 gas emissions measured prior to the 15 March 2007 paroxysmal explosion of Stromboli [1] have first demonstrated the chance to predict days in advance the effusive-to-explosive transition. Here 2007 and 2014 volcanic CO2 flux records have been compared for exploring causes/conditions that had not triggered any paroxysm event in the 2014 case. We show that the 2007 and 2014 datasets shared both similarities and remarkable differences. The pre-eruptive trends of CO2 and SO2 flux emissions were strikingly similar in both 2007 and 2014, indicating similar conditions within the plumbing system prior to onset of both effusive crises. In both events, the CO2 flux substantially accelerated (relative to the pre-eruptive mean flux) after onset of the effusion. However, this CO2 flux acceleration was a factor 3 lower in 2014 than in 2007, and the excess CO2 flux (the fraction of CO2 not associated with the shallowly emplaced/erupted magma, and therefore contributed by the deep magmatic system) never returned to the very high levels observed prior to the 15 March 2007 paroxysm. We conclude therefore that, although similar quantities of magma were effusively erupted in 2007 and 2014, the deep magmatic system was far less perturbed in the most recent case. We speculate that the rate at which the deep magmatic system is decompressed, rather than the level of de-compression itself, determine if the deep

  18. Development and characterization of basalt-glass ceramics for the immobilization of transuranic wastes

    International Nuclear Information System (INIS)

    Lokken, R.O.; Chick, L.A.; Thomas, L.E.

    1982-09-01

    Basalt-based waste forms were developed for the immobilization of transuranic (TRU) contaminated wastes. The specific waste studied is a 3:1 blend of process sludge and incinerator ash. Various amounts of TRU blended waste were melted with Pomona basalt powder. The vitreous products were subjected to a variety of heat treatment conditions to form glass ceramics. The total crystallinity of the glass ceramic, ranging from 20 to 45 wt %, was moderately dependent on composition and heat treatment conditions. Three parent glasses and four glass ceramics with varied composition and heat treatment were produced for detailed phase characterization and leaching. Both parent glasses and glass ceramics were mainly composed of a continuous, glassy matrix phase. This glass matrix entered into solution during leaching in both types of materials. The Fe-Ti rich dispersed glass phase was not significantly degraded by leaching. The glass ceramics, however, exhibited four to ten times less elemental releases during leaching than the parent glasses. The glass ceramic matrix probably contains higher Fe and Na and lower Ca and Mg relative to the parent glass matrix. The crystallization of augite in the glass ceramics is believed to contribute to the improved leach rates. Leach rates of the basalt glass ceramic are compared to those of other TRU nuclear waste forms containing 239 Pu

  19. Basaltic glasses from Iceland and the deep sea: Natural analogues to borosilicate nuclear waste-form glass

    International Nuclear Information System (INIS)

    Jercinovic, M.J.; Ewing, R.C.

    1987-12-01

    The report provides a detailed analysis of the alteration process and products for natural basaltic glasses. Information of specific applicability to the JSS project include: * The identification of typical alteration products which should be expected during the long-term corrosion process of low-silica glasses. The leached layers contain a relatively high proportion of crystalline phases, mostly in the form of smectite-type clays. Channels through the layer provide immediate access of solutions to the fresh glass/alteration layer interface. Thus, glasses are not 'protected' from further corrosion by the surface layer. * Corrosion proceeds with two rates - an initial rate in silica-undersaturated environments and a long-term rate in silica-saturated environments. This demonstrates that there is no unexpected change in corrosion rate over long periods of time. The long-term corrosion rate is consistent with that of borosilicate glasses. * Precipitation of silica-containing phases can result in increased alteration of the glass as manifested by greater alteration layer thicknesses. This emphasizes the importance of being able to predict which phases form during the reaction sequence. * For natural basaltic glasses the flow rate of water and surface area of exposed glass are critical parameters in minimizing glass alteration over long periods of time. The long-term stability of basalt glasses is enhanced when silica concentrations in solution are increased. In summary, there is considerable agreement between corrosion phenomena observed for borosilicate glasses in the laboratory and those observed for natural basalt glasses of great age. (With 121 refs.) (authors)

  20. Comparison of mechanical properties and structural changes of continous basalt and glass fibres at elevated temperatures

    Czech Academy of Sciences Publication Activity Database

    Černý, Martin; Glogar, Petr; Goliáš, V.; Hruška, J.; Jakeš, P.; Sucharda, Zbyněk; Vávrová, I.

    2007-01-01

    Roč. 51, č. 2 (2007), s. 82-88 ISSN 0862-5468 R&D Projects: GA ČR GA106/05/0817 Institutional research plan: CEZ:AV0Z30460519 Keywords : basalt fibre * glass fibre * tensile properties Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.488, year: 2007

  1. The morphology and evolution of the Stromboli 2002-2003 lava flow field--An example of a basaltic flow field emplaced on a steep slope

    Science.gov (United States)

    Lodato, Luigi; Harris, A.; Spampinato, L.; Calvari, Sonia; Dehn, J.; Patrick, M.

    2007-01-01

    The use of a hand-held thermal camera during the 2002–2003 Stromboli effusive eruption proved essential in tracking the development of flow field structures and in measuring related eruption parameters, such as the number of active vents and flow lengths. The steep underlying slope on which the flow field was emplaced resulted in a characteristic flow field morphology. This comprised a proximal shield, where flow stacking and inflation caused piling up of lava on the relatively flat ground of the vent zone, that fed a medial–distal lava flow field. This zone was characterized by the formation of lava tubes and tumuli forming a complex network of tumuli and flows linked by tubes. Most of the flow field was emplaced on extremely steep slopes and this had two effects. It caused flows to slide, as well as flow, and flow fronts to fail frequently, persistent flow front crumbling resulted in the production of an extensive debris field. Channel-fed flows were also characterized by development of excavated debris levees in this zone (Calvari et al. 2005). Collapse of lava flow fronts and inflation of the upper proximal lava shield made volume calculation very difficult. Comparison of the final field volume with that expecta by integrating the lava effusion rates through time suggests a loss of ~70% erupted lava by flow front crumbling and accumulation as debris flows below sea level. Derived relationships between effusion rate, flow length, and number of active vents showed systematic and correlated variations with time where spreading of volume between numerous flows caused an otherwise good correlation between effusion rate, flow length to break down. Observations collected during this eruption are useful in helping to understand lava flow processes on steep slopes, as well as in interpreting old lava–debris sequences found in other steep-sided volcanoes subject to effusive activity.

  2. Influences of chemical aging on the surface morphology and crystallization behavior of basaltic glass fibers

    DEFF Research Database (Denmark)

    Lund, Majbritt Deichgræber; Yue, Yuanzheng

    2008-01-01

    The impact of aging in high humidity and water on the surface morphology and crystallization behavior of basaltic glass fibers has been studied using scanning electron microscopy, transmission electron microscopy, calorimetry and X-ray diffraction. The results show that interaction between...... the fibers and the surrounding media (high humidity or water at 70 C) leads to chemical changes strongly affecting the surface morphology. The crystallization peak temperature of the basaltic glass fibers are increased without changing the onset temperature, this may be caused by a chemical depletion...

  3. Does the presence of bacteria effect basaltic glass dissolution rates? 1: Dead Pseudomonas reactants

    Science.gov (United States)

    Stockmann, Gabrielle J.; Shirokova, Liudmila S.; Pokrovsky, Oleg S.; Oelkers, Eric H.; Benezeth, Pascale

    2010-05-01

    Basaltic glass and crystalline basalt formations in Iceland have been suggested for industrial CO2 storage due to their porous and permeable properties and high reactivity. Acid CO2-saturated waters in contact with basaltic glass will lead to rapid dissolution of the glass and release of divalent cations, (Ca2+, Mg2+, Fe2+) that can react to form stable carbonates and thereby trap the CO2. However, the basalt formations in Iceland not only contains glass and mineral assemblages, but also host microbiological communities that either by their presence or by active involvement in chemical reactions could affect the amount of basaltic glass being dissolved and CO2 being trapped. Samples of natural bacteria communities from the CO2 storage grounds in Iceland were collected, separated, and purified using agar plate technique and cultured under laboratory conditions in nutrient broth-rich media. Heterotrophic aerobic Gram-negative strain of Pseudomonas reactants was selected for a series of flow-through experiments aimed at evaluation of basaltic glass dissolution rate in the presense of increasing amounts of dead bacteria and their lysis products. The experiments were carried out using mixed-flow reactors at pH 4, 6, 8 and 10 at 25 °C. Each of the four reactors contained 1 gram of basaltic glass of the size fraction 45-125 μm. This glass was dissolved in ~ 0.01 M buffer solutions (acetate, MES, bicarbonate and carbonate+bicarbonate mixture) of the desired pH. All experiments ran 2 months, keeping the flowrate and temperature stable and only changing the concentration of dead bacteria in the inlet solutions (from 0 to 430 mg/L). Experiments were performed in sterile conditions, and bacterial growth was prevented by adding NaN3 to the inlet solutions. Routine culturing of bacteria on the agar plates confirmed the sterility of experiments. Samples of outlet solutions were analyzed for major cations and trace elements by ICP-MS. Results demonstrate a slight decrease in the

  4. Effect of Crystallisation Degree on Hardness of Basaltic Glass-Ceramics

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Yue, Yuanzheng

    The dependence of hardness of basaltic glass-ceramics on their crystallisation degree has been explored by means of differential scanning calorimetry, optical microscopy, X-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses have been obtained...... by varying the temperature of heat treatment. The change of the relative degree of crystallisation with the heat treatment temperature can be described by an empirical model established in this work. The predominant crystalline phase in the glass has been identified as the pyroxene augite. The hardness...... principle calculations. It is found that the hardness of the glass phase decreases slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreases....

  5. Study of crystallization of a basalt glass; Estudo de cristalizacao de um vidro de basalto

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Fernando Takahiro; Hashizume, Camila Mina; Toffoli, Samuel Marcio, E-mail: toffoli@usp.b [Universidade de Sao Paulo (EP/USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2009-07-01

    Basalt vitreous ceramics posses industrial importance by presenting high mechanical resistance to the abrasion. It was studied the obtention and the crystallization of a glass obtained from a basalt of Campinas, Sao Paulo, Brazil, aiming to develop a material with great abrasive resistance. Fusions were made at 1400 deg Celsius in electrical oven and in alumina crucible, of fine residues of basalt mining. The obtained glass was treated in a crystallization temperature of 880 deg Celsius, determined by DSC, by various time of treatment. The present main crystalline phases, detected by XRD, were the magnesium-ferrite (MgFe{sub 2}O{sub 4}) and the diopsid Ca(Mg,Fe,Al)(Si,Al){sub 2}O{sub 6}. Analysing the density by the Archimedes methodology and the DRX it was possible to follow the crystallization kinetic up.

  6. Investigation of near-source basaltic glasses using {sup 57}Fe Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fern, G. R., E-mail: george.fern@brunel.ac.uk [Brunel University, Wolfson Centre for Materials Processing (United Kingdom); Mather, T. A.; Pyle, D. M. [University of Cambridge, Department of Earth Sciences (United Kingdom)

    2005-11-15

    Two basaltic glass samples have been studied, one from the Masaya volcano in Nicaragua and one from the Villarrica volcano in Chile using {sup 57}Fe Moessbauer spectroscopy. The iron(II) to iron(III) ratio has been determined for each sample. The 80 K data shows some separation of the sites and is fitted allowing for discrete doublets.

  7. Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, Dwijesh; Banerjee, R.; Iyer, S.D.; Basavalingu, B.; Mukhopadhyay, S.

    sub(2)0 with progressive fractionation, the basalts were gradually enriched in Y and Zr and depleted in Ni and Cr. In addition, the Sigma REE of magma also increased with fractionation, without any change in the (La/ Yb) sub(N) value. Glass from the VM...

  8. Electronic environments of ferrous iron in rhyolitic and basaltic glasses at high pressure: Silicate Glasses at High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Solomatova, Natalia V. [Division of Geological and Planetary Sciences, Caltech, Pasadena California USA; Jackson, Jennifer M. [Division of Geological and Planetary Sciences, Caltech, Pasadena California USA; Sturhahn, Wolfgang [Division of Geological and Planetary Sciences, Caltech, Pasadena California USA; Rossman, George R. [Division of Geological and Planetary Sciences, Caltech, Pasadena California USA; Roskosz, Mathieu [IMPMC-Muséum National d' Histoire Naturelle-CNRS, Paris France

    2017-08-01

    The physical properties of silicate melts within Earth's mantle affect the chemical and thermal evolution of its interior. Chemistry and coordination environments affect such properties. We have measured the hyperfine parameters of iron-bearing rhyolitic and basaltic glasses up to ~120 GPa and ~100 GPa, respectively, in a neon pressure medium using time domain synchrotron Mössbauer spectroscopy. The spectra for rhyolitic and basaltic glasses are well explained by three high-spin Fe2+-like sites with distinct quadrupole splittings. Absence of detectable ferric iron was confirmed with optical absorption spectroscopy. The sites with relatively high and intermediate quadrupole splittings are likely a result of fivefold and sixfold coordination environments of ferrous iron that transition to higher coordination with increasing pressure. The ferrous site with a relatively low quadrupole splitting and isomer shift at low pressures may be related to a fourfold or a second fivefold ferrous iron site, which transitions to higher coordination in basaltic glass, but likely remains in low coordination in rhyolitic glass. These results indicate that iron experiences changes in its coordination environment with increasing pressure without undergoing a high-spin to low-spin transition. We compare our results to the hyperfine parameters of silicate glasses of different compositions. With the assumption that coordination environments in silicate glasses may serve as a good indicator for those in a melt, this study suggests that ferrous iron in chemically complex silicate melts likely exists in a high-spin state throughout most of Earth's mantle.

  9. Green glass vitrophyre 78526 - An impact of very low-Ti mare basalt composition

    Science.gov (United States)

    Warner, R. D.; Taylor, G. J.; Kiel, K.; Planner, H. H.; Nehru, C. E.; Ma, M.-S.; Schmitt, R. A.

    1978-01-01

    Rake sample 78526 is an 8.77 g rock consisting primarily of vitrophyric pale green glass with subordinate mineral and lithic relics. Petrographic and compositional evidence leads to the following conclusions: (1) the bulk composition represents that of a mixture formed by impact melting of at least two different textural and compositional varieties of VLT mare basalt that are now present in the rock as lithic relics and a poorly defined low-Ti mare basalt component observed in thin section only in the form of isolated mineral relics; (2) the admixed VLT mare basalts had REE abundances lower than those found in other mare basalts (but probably higher than emerald green glass) and REE patterns showing significant enrichment of the heavy relative to light REE's, suggesting that they were derived by comparatively high degrees of partial melting of a clinopyroxene-rich source region; and (3) the impact melt supercooled to produce the vitrophyre, with rather sharply contrasting textural domains present in the vitrophyre resulting from differences in nucleation kinetics and degrees of supercooling in various portions of the sample.

  10. Post-impact mechanical characterisation of E-glass/basalt woven fabric interply hybrid laminates

    Directory of Open Access Journals (Sweden)

    2011-05-01

    Full Text Available Post-impact properties of different configurations (symmetrical and non-symmetrical of hybrid laminates including E-glass and basalt fibre composites, all with volume fraction of fibres equal to 0.38±0.02 and manufactured by RTM, have been studied. With this aim, interlaminar shear strength tests and four-point flexural tests of laminates impacted with different energies (0, 7.5, 15 and 22.5 J have been performed. Acoustic emission (AE localisation and AE evolution with applied flexural stress was studied to support impact damage characterisation, provided by SEM and transient thermography. The results indicate that a symmetrical configuration including E-glass fibre laminate as a core for basalt fibre laminate skins presents the most favourable degradation pattern, whilst intercalation of layers may bring to further improvement of the laminate properties, but also to more extended and complex damage patterns.

  11. Microbial colonization of basaltic glasses in hydrothermal organic-rich sediments at Guaymas Basin

    Science.gov (United States)

    Callac, Nolwenn; Rommevaux-Jestin, Céline; Rouxel, Olivier; Lesongeur, Françoise; Liorzou, Céline; Bollinger, Claire; Ferrant, Antony; Godfroy, Anne

    2013-01-01

    Oceanic basalts host diverse microbial communities with various metabolisms involved in C, N, S, and Fe biogeochemical cycles which may contribute to mineral and glass alteration processes at, and below the seafloor. In order to study the microbial colonization on basaltic glasses and their potential biotic/abiotic weathering products, two colonization modules called AISICS (“Autonomous in situ Instrumented Colonization System”) were deployed in hydrothermal deep-sea sediments at the Guaymas Basin for 8 days and 22 days. Each AISICS module contained 18 colonizers (including sterile controls) filled with basaltic glasses of contrasting composition. Chemical analyses of ambient fluids sampled through the colonizers showed a greater contribution of hydrothermal fluids (maximum temperature 57.6°C) for the module deployed during the longer time period. For each colonizer, the phylogenetic diversity and metabolic function of bacterial and archaeal communities were explored using a molecular approach by cloning and sequencing. Results showed large microbial diversity in all colonizers. The bacterial distribution was primarily linked to the deployment duration, as well as the depth for the short deployment time module. Some 16s rRNA sequences formed a new cluster of Epsilonproteobacteria. Within the Archaea the retrieved diversity could not be linked to either duration, depth or substrata. However, mcrA gene sequences belonging to the ANME-1 mcrA-guaymas cluster were found sometimes associated with their putative sulfate-reducers syntrophs depending on the colonizers. Although no specific glass alteration texture was identified, nano-crystals of barite and pyrite were observed in close association with organic matter, suggesting a possible biological mediation. This study gives new insights into the colonization steps of volcanic rock substrates and the capability of microbial communities to exploit new environmental conditions. PMID:23986754

  12. Evidence for microbial activity at the glass-alteration interface in oceanic basalts

    Science.gov (United States)

    Torsvik, Terje; Furnes, Harald; Muehlenbachs, Karlis; Thorseth, Ingunn H.; Tumyr, Ole

    1998-10-01

    A detailed microbiological and geochemical study related to the alteration of basaltic glass of pillow lavas from the oceanic crust recovered from Hole 896A on the Costa Rica Rift (penetrating 290 m into the volcanic basement) has been carried out. A number of independent observations, pointing to the influence of microbes, may be summarized as follows: (1) Alteration textures are reminiscent of microbes in terms of form and shape. (2) Altered material contains appreciable amounts of C, N and K, and the N/C ratios are comparable to those of nitrogen-starved bacteria. (3) Samples stained with a dye (DAPI) that binds specifically to nucleic acids show the presence of DNA in the altered glass. Further, staining with fluorescent labeled oligonucleotide probes that hybridize specifically to 16S-ribosomal RNA of bacteria and archaea demonstrate their presence in the altered part of the glass. (4) Disseminated carbonate in the glassy margin of the majority of pillows shows δ 13C values, significantly lower than that of fresh basalt, also suggests biological activity. The majority of the samples have δ 18O values indicating temperatures of 20-100°C, which is in the range of mesophilic and thermophilic micro-organisms.

  13. Modification of the epoxy binder for glass and basalt rebar. Mechanical test results

    Science.gov (United States)

    Brusentseva, T. A.

    2017-10-01

    The paper presents the results of experimental studies on the modification of the epoxy binder LE-828 for the manufacture of glass and basalt rebar. The nano-size silica powder is used as a filler. The filler mass content ranged from 0% to 2%. It is shown that the nano-disperse filler introduced in the binder leads to the increasing breaking stress and tensile strength by 33% and 34%, respectively; the failure strain increased by 39% at the filler mass content of 0.6%.

  14. Augite-anorthite glass-ceramics from residues of basalt quarry and ceramic wastes

    Directory of Open Access Journals (Sweden)

    Gamal A. Khater

    2015-06-01

    Full Text Available Dark brown glasses were prepared from residues of basalt quarries and wastes of ceramic factories. Addition of CaF2, Cr2O3 and their mixture CaF2-Cr2O3 were used as nucleation catalysts. Generally, structures with augite and anorthite as major phases and small amount of magnetite and olivine phases were developed through the crystallization process. In the samples heat treated at 900 °C the dominant phase is augite, whereas the content of anorthite usually overcomes the augite at higher temperature (1100 °C. Fine to medium homogenous microstructures were detected in the prepared glass-ceramic samples. The coefficient of thermal expansion and microhardness measurements of the glass-ceramic samples were from 6.16×10-6 to 8.96×10-6 °C-1 (in the 20–500 °C and 5.58 to 7.16 GP, respectively.

  15. Phosphorus Adsorption and Desorption Properties of Minnesota Basalt Lunar Simulant and Lunar Glass Simulant

    Science.gov (United States)

    Sutter, Brad; Hossner, Lloyd R.; Ming, Douglas W.

    1996-01-01

    Phosphorus (P) adsorption and desorption characteristics of Minnesota Basalt Lunar Simulant (MBLS) and Lunar Glass Simulant (LGS) were evaluated. Results of P interactions with lunar simulants indicated that mineral and glass components adsorbed between 50 and 70% of the applied P and that between 85 and 100% of the applied P was desorbed. The Extended Freundlich equation best described the adsorption data (r(sup 2) = 0.92), whereas the Raven/Hossner equation best described the desorption data ((r(sup 2) = 0.97). Kinetic desorption results indicated that MBLS and LGS released most of their P within 15 h. The expanded Elovich equation fit the data best at shorter times while t/Q(sub DT) equation had a better fit at longer times. These results indicate that P does not strongly adsorb to the two simulants and that any P that was adsorbed was readily desorbed in the presence of anion exchange resin. This work suggests that multiple small applications of P (10-20 mg P/kg) should be added to the simulants to ensure adequate solution P for plant uptake and efficient use of P fertilizer.

  16. Calibrating Carbon Measurements in Basaltic Glass Using SIMS and FTIR: The Effect of Variable H2O Contents

    Science.gov (United States)

    Hervig, R. L.; Moore, G. M.; Roggensack, K.

    2009-12-01

    The effect of mixed volatiles (H2O + CO2) dissolved in basaltic glass on the calibrations of Fourier transform infra-red spectrometry (FTIR) and secondary ion mass spectrometry (SIMS) for H2O and CO2 is assessed. A series of mixed volatile-bearing calc-alkaline basalts were synthesized and analyzed using high-T vacuum manometry, FTIR, and SIMS. No significant deviations from the single volatile component calibrations were found for the FTIR method. The SIMS analyses of these well-characterized basaltic glasses were conducted in three different analytical modes: 1) using a Cs+ primary beam and detection of negative secondary ions shows that the yield of negative carbon ions shows minor (if any) change for H2O contents up to ~3 wt.% but decreases by nearly two-fold in glasses containing ≥5.5 wt.% H2O, 2) using an O- primary beam and detection of negative or positive secondary ions provides linear calibrations for CO2 concentrations in basalts and does not show a significant effect of H2O on the carbon ion yield. Testing the above SIMS approaches for determining H2O in mixed-volatile basaltic glasses shows: a) no effect of carbon on the yield of hydrogen ions, and b) the lowest background levels are achieved by using Cs+ or O- primary beams and detection of negative secondary ions. The analyses using O- primary beams and detection of negative secondary ions results in high session-to-session reproducibility and are also very simple, allowing visitors to SIMS laboratories to obtain high-quality microanalyses for H and C (and F & Cl) with minimal training. Analyses for carbon using positive secondary ions shows low sensitivity, and requires operation of the SIMS at high enough mass resolving power to eliminate interfering 24Mg2+ ions, but does represent an approach for adding C measurements to SIMS analyses of lithophile elements in melt inclusions.

  17. The effects of stacking sequence and thermal cycling on the flexural properties of laminate composites of aluminium-epoxy/basalt-glass fibres

    Science.gov (United States)

    Abdollahi Azghan, Mehdi; Eslami-Farsani, Reza

    2018-02-01

    The current study aimed at investigating the effects of different stacking sequences and thermal cycling on the flexural properties of fibre metal laminates (FMLs). FMLs were composed of two aluminium alloy 2024-T3 sheets and epoxy polymer-matrix composites that have four layers of basalt and/or glass fibres with five different stacking sequences. For FML samples the thermal cycle time was about 6 min for temperature cycles from 25 °C to 115 °C. Flexural properties of samples evaluated after 55 thermal cycles and compared to non-exposed samples. Surface modification of aluminium performed by electrochemical treatment (anodizing) method and aluminium surfaces have been examined by scanning electron microscopy (SEM). Also, the flexural failure mechanisms investigated by the optical microscope study of fractured surfaces. SEM images indicated that the porosity of the aluminium surface increased after anodizing process. The findings of the present study showed that flexural modulus were maximum for basalt fibres based FML, minimum for glass fibres based FML while basalt/glass fibres based FML lies between them. Due to change in the failure mechanism of basalt/glass fibres based FMLs that have glass fibres at outer layer of the polymer composite, the flexural strength of this FML is lower than glass and basalt fibres based FML. After thermal cycling, due to the good thermal properties of basalt fibres, flexural properties of basalt fibres based FML structures decreased less than other composites.

  18. Structural Iron (II) of Basaltic Glass as an Energy Source for Zetaproteobacteria in an Abyssal Plain Environment, Off the Mid Atlantic Ridge.

    Science.gov (United States)

    Henri, Pauline A; Rommevaux-Jestin, Céline; Lesongeur, Françoise; Mumford, Adam; Emerson, David; Godfroy, Anne; Ménez, Bénédicte

    2015-01-01

    To explore the capability of basaltic glass to support the growth of chemosynthetic microorganisms, complementary in situ and in vitro colonization experiments were performed. Microbial colonizers containing synthetic tholeitic basaltic glasses, either enriched in reduced or oxidized iron, were deployed off-axis from the Mid Atlantic Ridge on surface sediments of the abyssal plain (35°N; 29°W). In situ microbial colonization was assessed by sequencing of the 16S rRNA gene and basaltic glass alteration was characterized using Scanning Electron Microscopy, micro-X-ray Absorption Near Edge Structure at the Fe-K-edge and Raman microspectroscopy. The colonized surface of the reduced basaltic glass was covered by a rind of alteration made of iron-oxides trapped in a palagonite-like structure with thicknesses up to 150 μm. The relative abundance of the associated microbial community was dominated (39% of all reads) by a single operational taxonomic unit (OTU) that shared 92% identity with the iron-oxidizer Mariprofundus ferrooxydans PV-1. Conversely, the oxidized basaltic glass showed the absence of iron-oxides enriched surface deposits and correspondingly there was a lack of known iron-oxidizing bacteria in the inventoried diversity. In vitro, a similar reduced basaltic glass was incubated in artificial seawater with a pure culture of the iron-oxidizing M. ferrooxydans DIS-1 for 2 weeks, without any additional nutrients or minerals. Confocal Laser Scanning Microscopy revealed that the glass surface was covered by twisted stalks characteristic of this iron-oxidizing Zetaproteobacteria. This result supported findings of the in situ experiments indicating that the Fe(II) present in the basalt was the energy source for the growth of representatives of Zetaproteobacteria in both the abyssal plain and the in vitro experiment. In accordance, the surface alteration rind observed on the reduced basaltic glass incubated in situ could at least partly result from their activity.

  19. Structural iron (II of basaltic glass as an energy source for Zetaproteobacteria in an abyssal plain environment, off the Mid Atlantic Ridge

    Directory of Open Access Journals (Sweden)

    Pauline Audrey Henri

    2016-01-01

    Full Text Available To explore the capability of basaltic glass to support the growth of chemosynthetic microorganisms, complementary in situ and in vitro colonization experiments were performed. Microbial colonizers containing synthetic tholeitic basaltic glasses, either enriched in reduced or oxidized iron, were deployed off-axis from the Mid Atlantic Ridge on surface sediments of the abyssal plain (35°N; 29°W. In situ microbial colonization was assessed by sequencing of the 16S rRNA gene and basaltic glass alteration was characterized using Scanning Electron Microscopy, micro-X-ray Absorption Near Edge Structure at the Fe-K-edge and Raman microspectroscopy. The colonized surface of the reduced basaltic glass was covered by a rind of alteration made of iron-oxides trapped in a palagonite-like structure with thicknesses up to 150 µm. The relative abundance of the associated microbial community was dominated (39% of all reads by a single operational taxonomic unit (OTU that shared 92% identity with the iron-oxidizer Mariprofundus ferrooxydans PV-1. Conversely, the oxidized basaltic glass showed the absence of iron-oxides enriched surface deposits and correspondingly there was a lack of known iron-oxidizing bacteria in the inventoried diversity. In vitro, a similar reduced basaltic glass was incubated in artificial seawater with a pure culture of the iron-oxidizing M. ferrooxydans DIS-1 for 2 weeks, without any additional nutrients or minerals. Confocal Laser Scanning Microscopy revealed that the glass surface was covered by twisted stalks characteristic of this iron-oxidizing Zetaproteobacteria. This result supported findings of the in situ experiments indicating that the Fe(II present in the basalt was the energy source for the growth of representatives of Zetaproteobacteria in both the abyssal plain and the in vitro experiment. In accordance, the surface alteration rind observed on the reduced basaltic glass incubated in situ could at least partly result from

  20. Natural fumarolic alteration of fluorapatite, olivine, and basaltic glass, and implications for habitable environments on Mars.

    Science.gov (United States)

    Hausrath, Elisabeth M; Tschauner, Oliver

    2013-11-01

    Fumaroles represent a very important potential habitat on Mars because they contain water and nutrients. Global deposition of volcanic sulfate aerosols may also have been an important soil-forming process affecting large areas of Mars. Here we identify alteration from the Senator fumarole, northwest Nevada, USA, and in low-temperature environments near the fumarole to help interpret fumarolic and acid vapor alteration of rocks and soils on Mars. We analyzed soil samples and fluorapatite, olivine, and basaltic glass placed at and near the fumarole in in situ mineral alteration experiments designed to measure weathering under natural field conditions. Using synchrotron X-ray diffraction, we clearly observe hydroxyl-carbonate-bearing fluorapatite as a fumarolic alteration product of the original material, fluorapatite. The composition of apatites as well as secondary phosphates has been previously used to infer magmatic conditions as well as fumarolic conditions on Mars. To our knowledge, the observations reported here represent the first documented instance of formation of hydroxyl-carbonate-bearing apatite from fluorapatite in a field experiment. Retreat of olivine surfaces, as well as abundant NH4-containing minerals, was also characteristic of fumarolic alteration. In contrast, alteration in the nearby low-temperature environment resulted in formation of large pits on olivine surfaces, which were clearly distinguishable from the fumarolic alteration. Raman signatures of some fumarolically impacted surfaces are consistent with detection of the biological molecules chlorophyll and scytenomin, potentially useful biosignatures. Observations of altered minerals on Mars may therefore help identify the environment of formation and understand the aqueous history and potential habitability of that planet.

  1. Sulfur and iron speciation in gas-rich impact-melt glasses from basaltic shergottites determined by microXANES

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, S.R.; Rao, M.N.; Nyquist, L.E. (UofC); (Johnson Space Center)

    2008-04-28

    Sulfur and iron K XANES measurements were made on GRIM glasses from EET 79001. Iron is in the ferrous state. Sulfur speciation is predominately sulfide coordination but is Fe coordinated in Lith B and, most likely, Ca coordinated in Lith A. Sulfur is abundantly present as sulfate near Martian surface based on chemical and mineralogical investigations on soils and rocks in Viking, Pathfinder and MER missions. Jarosite is identified by Moessbauer studies on rocks at Meridian and Gusev, whereas MgSO{sub 4} is deduced from MgO-SO{sub 3} correlations in Pathfinder MER and Viking soils. Other sulfate minerals such as gypsum and alunogen/S-rich aluminosilicates and halides are detected only in martian meteorites such as shergottites and nakhlites using SEM/FE-SEM and EMPA techniques. Because sulfur has the capacity to occur in multiple valence states, determination of sulfur speciation (sulfide/sulfate) in secondary mineral assemblages in soils and rocks near Mars surface may help us understand whether the fluid-rock interactions occurred under oxidizing or reducing conditions. On Earth, volcanic rocks contain measurable quantities of sulfur present as both sulfide and sulfate. Carroll and Rutherford showed that oxidized forms of sulfur may comprise a significant fraction of total dissolved sulfur, if the oxidation state is higher than {approx}2 log fO{sub 2} units relative to the QFM buffer. Terrestrial samples containing sulfates up to {approx}25% in fresh basalts from the Galapagos Rift on one hand and high sulfide contents present in oceanic basalts on the other indicate that the relative abundance of sulfide and sulfate varies depending on the oxygen fugacity of the system. Basaltic shergottites (bulk) such as Shergotty, EET79001 and Zagami usually contain small amounts of sulfur ({approx}0.5%) as pyrrhotite. But, in isolated glass pockets containing secondary salts (known as GRIM glasses) in these meteorites, sulfur is present in high abundance ({approx}1-12%). To

  2. Tracking the Depleted Mantle Signature in Melt Inclusions and Residual Glass of Basaltic Martian Shergottites using Secondary Ionization Mass Spectrometry

    Science.gov (United States)

    Peters, Timothy J.; Simon, Justin I.; Jones, John H.; Usui, Tomohiro; Economos, Rita C.; Schmitt, Axel K.; McKeegan, Kevin D.

    2013-01-01

    Trace element abundances of depleted shergottite magmas recorded by olivine-hosted melt inclusions (MI) and interstitial mesostasis glass were measured using the Cameca ims-1270 ion microprobe. Two meteorites: Tissint, an olivine-­phyric basaltic shergottite which fell over Morocco July 18th 2001; and the Antarctic meteorite Yamato 980459 (Y98), an olivine-phyric basaltic shergottite with abundant glassy mesostasis have been studied. Chondrite-­normalized REE patterns for MI in Tissint and Y98 are characteristically LREE depleted and, within analytical uncertainty, parallel those of their respective whole rock composition; supporting each meteorite to represent a melt composition that has experienced closed-­system crystallization. REE profiles for mesostasis glass in Y98 lie about an order of magnitude higher than those from the MI; with REE profiles for Tissint MI falling in between. Y98 MI have the highest average Sm/Nd and Y/Ce ratios, reflecting their LREE depletion and further supporting Y98 as one of our best samples to probe the depleted shergotitte mantle. In general, Zr/Nb ratios overlap between Y98 and Tissint MI, Ce/Nb ratios overlap between Y98 MI and mesostasis glass, and Sm/Nd ratios overlap between Y98 mesostasis glass and Tissint MI. These features support similar sources for both, but with subtle geochemical differences that may reflect different melting conditions or fractionation paths during ascent from the mantle. Interestingly, the REE patterns for both Y98 bulk and MI analyses display a flattening of the LREE that suggests a crustal contribution to the Y98 parent melt. This observation has important implications for the origins of depleted and enriched shergottites.

  3. Mineralogical textural and compositional data on the alteration of basaltic glass from Kilauea, Hawaii to 300 degrees C: Insights to the corrosion of a borosilicate glass waste-form

    International Nuclear Information System (INIS)

    Smith, D.K.

    1990-01-01

    Mineralogical, textural and compositional data accompanying greenschist facies metamorphism (to 300 degrees C) of basalts of the East Rift Zone (ERZ), Kilauea, Hawaii may be evaluated relative to published and experimental results for the surface corrosion of borosilicate glass. The ERZ alteration sequence is dominated by intermittent palagonite, interlayered smectite-chlorite, chlorite, and actinolite-epidote-anhydrite. Alteration is best developed in fractures and vesicles where surface reaction layers root on the glass matrix forming rinds in excess of 100 microns thick. Fractures control fluid circulation and the alteration sequence. Proximal to the glass surface, palagonite, Fe-Ti oxides and clays replace fresh glass as the surface reaction layer migrates inwards; away from the surface, amphibole, anhydrite, quartz and calcite crystallize from hydrothermal fluids in contact with the glass. The texture and composition of basaltic glass surfaces are similar to those of a SRL-165 glass leached statically for sixty days at 150 degrees C. While the ERZ reservoir is a complex open system, conservative comparisons between the alteration of ERZ and synthetic borosilicate glass are warranted. 31 refs., 2 figs

  4. Experimental seawater-basaltic glass interaction at 50°C: Study of early developed phases by electron microscopy and X-ray photoelectron spectrometry

    Science.gov (United States)

    Crovisier, J. L.; Thomassin, J. H.; Juteau, T.; Eberhart, J. P.; Touray, J. C.; Baillif, P.

    1983-03-01

    Experiments on seawater-basaltic glass interaction were made using a particulary high seawater-basaltic glass ratio (14.5 g/cm 2; weight ratio: 50). A layered alteration skin is observed at the glass surface, while the variations in the composition of the seawater are imperceptible. Three zones of different composition and structure are distinguished: 1) An external zone, the composition of which evolved to saponite. 2) A median zone of hydrotalcite-like hydroxycarbonate (Mg 6Al 2CO 3(OH) 164H 2O). 3) An internal zone, between glass and hydroxycarbonates, richer in Fe and in Mg and in which a 10 Å interval is observed (by dark field examination) compatible with a TOT type clay mineral. The composition of this zone indicates a mixing of poorly crystalline products. The principal chemical exchanges between glass and solution are the release of Ca in solution and the contribution of Mg and CO 2 from seawater to form hydroxycarbonates, which are considered precursors of phyllosilicates. Comparison with natural phenomena (palagonitization) is made.

  5. Basaltic glass formed from hydrovolcanism and impact processes: Characterization and clues for detection of mode of origin from VNIR through MWIR reflectance and emission spectroscopy

    Science.gov (United States)

    Farrand, W. H.; Wright, S. P.; Rogers, A. D.; Glotch, T. D.

    2016-09-01

    The CheMin X-ray diffraction instrument on-board the Curiosity rover in Gale crater has measured a consistent X-ray amorphous component in drill core samples examined to-date, clearly demonstrating that X-ray amorphous materials are a significant fraction of the martian surface layer. Glasses are potential components of this amorphous material and in this study, basaltic tephras from several hydro- and glaciovolcanic centers, as well as impact melts from India's Lonar Crater, were examined using thin section petrography, visible and near-infrared reflectance and mid-wave infrared emission spectroscopy as well as measuring major and minor element chemistry of representative samples using X-ray fluorescence (XRF) spectroscopy. The objectives of this study have been to look for distinguishing characteristics between volcanic and impact glasses and to determine features that indicate whether the glasses are fresh or altered using methods available on current and planned Mars rovers. Spectral features in the visible and near-infrared (VNIR) that can be used as indicators of alteration include the development of hydration features at 1.9 and ∼3 μm and a feature attributed to ferric oxide development at 0.48 μm. In the mid-wave infrared, it was observed that glass-rich tephra field samples did not display a broad, disordered glass feature near 9-10 μm (as is observed in pristine basaltic glasses) but rather a doublet with centers near 9.5 and 11 μm attributed in earlier work to incipient devitrification into SiO4 chain and sheet structures respectively. A tentative observation was made that the Si-O bending feature, observed in all the sample spectra near 22 μm was broader in the hydro- and glaciovolcanic glass samples than in the impact glass samples. Hydro- and glaciovolcanic glass-rich tephra samples were used as library spectra in linear deconvolution analyses of Mars Global Surveyor Thermal Emission Spectrometer (MGS TES) surface spectral types. These

  6. Energy budget of the volcano Stromboli, Italy

    Science.gov (United States)

    Mcgetchin, T. R.; Chouet, B. A.

    1979-01-01

    The results of the analyses of movies of eruptions at Stromboli, Italy, and other available data are used to discuss the question of its energy partitioning among various energy transport mechanisms. Energy is transported to the surface from active volcanoes in at least eight modes, viz. conduction (and convection) of the heat through the surface, radiative heat transfer from the vent, acoustical radiation in blast and jet noise, seismic radiation, thermal energy of ejected particles, kinetic energy of ejected particles, thermal energy of ejected gas, and kinetic energy of ejected gas. Estimated values of energy flux from Stromboli by these eight mechanisms are tabulated. The energy budget of Stromboli in its normal mode of activity appears to be dominated by heat conduction (and convection) through the ground surface. Heat carried by eruption gases is the most important of the other energy transfer modes. Radiated heat from the open vent and heat carried by ejected lava particles also contribute to the total flux, while seismic energy accounts for about 0.5% of the total. All other modes are trivial by comparison.

  7. A spatter-forming, large-scale paroxysm at Stromboli Volcano (Aeolian Islands, Italy): insight into magma evolution and eruption dynamics

    Science.gov (United States)

    La Felice, Sonia; Landi, Patrizia

    2011-11-01

    This study focuses on a pyroclastic sequence related to a large-scale paroxysm that occurred during the seventeenth century ad and which can be considered one of the most powerful and hazardous explosive events at the volcano in the past few centuries. Paroxysms are energetic, short-lived explosions which sporadically interrupt normal Strombolian activity at Stromboli and commonly erupt a deep-derived, volatile-rich crystal-poor high-potassium basalt ("low porphyricity" (LP)), together with a shallow, degassed crystal-rich high-potassium to shoshonitic basalt ("high porphyricity" (HP)), which feed normal activity at the volcano. The studied deposit, crops out along the flanks of Sciara del Fuoco and, from base to top, consists of: (1) a layer of HP and LP ash and lapilli; (2) an unwelded layer of coarse HP lapilli and flattened dark scoriae; (3) weakly welded spatter made up of dense HP pyroclasts at the base, overlain by strongly vesicular LP clasts. The textural and chemical zoning of minerals and the glass chemistry of the LP products record repeated mafic recharge events, mixing with an old mushy body and episodes of rapid crystallization due to sudden degassing. Collapse of a foam layer originated by deep degassing probably triggered this large-scale, spatter-forming paroxysm. Decompression induced rapid degassing and vesiculation of the deep volatile-rich magma. The rapid ascent of the foamy magma blob pushed the shallow HP magma out and finally produced a fire fountain that emplaced the LP portion of the spatter.

  8. Comparing biosignatures in aged basalt glass from North Pond, Mid-Atlantic Ridge and the Louisville Seamount Trail, off New Zealand.

    Directory of Open Access Journals (Sweden)

    Andreas Türke

    Full Text Available Microbial life can leave various traces (or biosignatures in rocks, including biotic alteration textures, biominerals, enrichments of certain elements, organic molecules, or remnants of DNA. In basalt glass from the ocean floor, microbial alteration textures as well as chemical and isotopic biosignatures have been used to trace microbial activity. However, little is known about the relationship between the physical and chemical nature of the habitat and the prevalent types of biosignatures. Here, we report and compare strongly variable biosignatures from two different oceanic study sites. We analyzed rock samples for their textural biosignatures and associated organic molecules. The biosignatures from the 8 Ma North Pond Region, which represents young, well-oxygenated, and hydrologically active crust, are characterized by little textural diversity. The organic matter associated with those textures shows evidence for the occurrence of remnants of complex biomolecules like proteins. Comparably the biosignatures from the older Louisville Seamount Trail (~70 Ma are more texturally diverse, but associated with organic molecules that are more degraded. The Louisville Seamount has less fresh glass left and decreased permeability, which metabolic pathways may dominate that only leave molecular biosignatures without textural evidence of glass alteration. We propose that diverse biosignatures in oceanic crust may form during different stages of crustal evolution.

  9. Sulfur Isotope Variation in Basaltic Melt Inclusions from Krakatau Revealed by a Newly Developed Secondary Ion Mass Spectrometry Technique for Silicate Glasses

    Science.gov (United States)

    Mandeville, C. W.; Shimizu, N.; Kelley, K. A.; Cheek, L.

    2008-12-01

    Sulfur is a ubiquitous element with variable valance states (S2-, S0, S4+, S6+) allowing for its participation in a wide variety of chemical and biogeochemical processes. However, its potential as an isotopic tracer in magmatic processes has not been fully developed and is crucial to understanding of sulfur recycling in subduction zones and between Earth's major reservoirs, mantle, lithosphere and coupled hydrosphere-atmosphere. Previous studies of silicate glasses and melt inclusions have been hampered by lack of an in situ isotopic measurement technique with spatial resolution of 10 to 100 microns. We have developed a new secondary ion mass spectrometry (SIMS) analytical technique for measurement of 34S/32S ratios in silicate glasses utilizing the IMS 1280 at Woods Hole Oceanographic Institution. A beam of 133Cs+ ions with 13 keV energy and current of 1-2 nA is focused onto a 10 micron spot and rastered over 30 × 30 microns. A Normal Incidence Electron Gun was used to compensate excess charge. The rastered beam is then centered to the optical axis of the machine, and a mechanical aperture is placed on the image plane to limit the area of analysis to the central 15 × 15 microns. The energy slit width was adjusted to 50 eV. A mass resolving power of 5500 was sufficient for eliminating mass interferences. A suite of synthetic and natural glasses with δ34SVCDT values spanning from - 5.6‰ to 18.5‰ with SiO2 from 44-72 weight % were measured. Magnitude of the instrumental mass fractionation (α) for 34S/32S ratios is 0.991 and is constant for all the glasses measured despite their compositions. Precision of individual measurements of 34S/32S ratios is 0.4 ‰, or better. Preliminary δ34S measurements of olivine-hosted basaltic melt inclusions in pre- 1883 basaltic scoria from Krakatau volcano Indonesia vary from -5.6 to 7.9‰ with sulfur concentrations from 490 to 2170 ppm, respectively. Host olivines are Fo77-80 and inclusions generally need minor to no post

  10. Can Plant-Based Natural Flax Replace Basalt and E-Glass for Fiber-Reinforced Polymer Tubular Energy Absorbers? A Comparative Study on Quasi-Static Axial Crushing

    Directory of Open Access Journals (Sweden)

    Libo Yan

    2017-12-01

    Full Text Available Using plant-based natural fibers to substitute glass fibers as reinforcement of composite materials is of particular interest due to their economic, technical, and environmental significance. One potential application of plant-based natural fiber reinforced polymer (FRP composites is in automotive engineering as crushable energy absorbers. Current study experimentally investigated and compared the energy absorption efficiency of plant-based natural flax, mineral-based basalt, and glass FRP (GFRP composite tubular energy absorbers subjected to quasi-static axial crushing. The effects of number of flax fabric layer, the use of foam filler and the type of fiber materials on the crashworthiness characteristics, and energy absorption capacities were discussed. In addition, the failure mechanisms of the hollow and foam-filled flax, basalt, and GFRP tubes in quasi-static axial crushing were analyzed and compared. The test results showed that the energy absorption capabilities of both hollow and foam-filled energy absorbers made of flax were superior to the corresponding energy absorbers made of basalt and were close to energy absorbers made of glass. This study, therefore, indicated that flax fiber has the great potential to be suitable replacement of basalt and glass fibers for crushable energy absorber application.

  11. Apollo 15 yellow-brown volcanic glass - Chemistry and petrogenetic relations to green volcanic glass and olivine-normative mare basalts

    Science.gov (United States)

    Hughes, S. S.; Schmitt, R. A.; Delano, J. W.

    1988-01-01

    Electron microprobe and INAA were used to analyze forty spherules of Apollo 15 yellow-brown glass for major and trace elements. The glass is one of twenty-five high-Mg primary magmas emplaced on the lunar surface in pyroclastic eruptions. The abundances show that the magma was produced by partial melting of differentiated cumulates in the lunar mantle. Models to explain the possible source-regions of several Apollo 15 and Apollo 12 low-Ti mare magmas are presented.

  12. The November 2009 paroxysmal explosions at Stromboli

    Science.gov (United States)

    Andronico, Daniele; Pistolesi, Marco

    2010-09-01

    Two paroxysmal explosions occurred at Stromboli volcano (Italy) on 8 and 24 November 2009. Analysis of recordings (from video-camera surveillance) indicates that each paroxysm consisted of multiple bursts from different vents. Field surveys, carried out within a few days after the two paroxysmal events, allowed us to gather crucial data on eruptive deposits and document morphological variations occurring at the source vents. Integration of video-analysis and field observations allowed making inferences on the eruptive dynamics of each explosive paroxysm. The 24 November event, in particular, erupted a larger volume and coarser products dispersed further from the summit area, resulting in a more hazardous event compared to the 8 November event that was largely confined to the upper part of the volcano.

  13. Apollo 15 yellow-brown volcanic glass: Chemistry and petrogenetic relations to green volcanic glass and olivine-normative mare basalts

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, S.S.; Schmitt, R.A.; (Oregon State Univ., Corvallis (USA)); Delano, J.W. (State Univ. of New York, Albany (USA))

    1988-10-01

    Apollo 15 yellow-brown glass is one of twenty-five, high Mg, primary magmas emplaced on the lunar surface in pyroclastic eruptions. Forty spherules of this glass were individually analyzed by electron microprobe and INAA for major- and trace-elements. The abundances demonstrate that this primary magma was produced by partial melting of differentiated cumulates in the lunar mantle. Models are developed to explain the possible source-regions of several Apollo 15 and Apollo 12 low-Ti mare magmas as being products of hybridization involving three ancient differentiated components of a primordial lunar magma ocean: (a) early olivine {plus minus} orthopyroxene cumulates; (b) late-stage clinopyroxene + pigeonite + ilmenite + plagioclase cumulates; and (c) late-stage inter-cumulus liquid.

  14. Petrology of offshore basalts of Bombay harbour area, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.

    glass are conspicuous. The chemical data indicate that the basalts are tholeiitic. Secondary minerals encountered support the view that the basalts are spilitised. Basalts of this area show affinities to both continental and oceanic types especially...

  15. Determination by activation analysis of volatile metals and other elements in volcanic exhalations collected at Vulcano and Stromboli, Italy

    International Nuclear Information System (INIS)

    Bichler, M.; Platschka, R.; Poljanc, K.

    1992-01-01

    Hot gases of volcanic origin (fumaroles) were sampled by means of an activated charcoal filter. The charcoal was specially prepared by a high temperature - vacuum treatment. Mercury, arsenic, bromine, antimony and selenium were determined by activation analysis and compared with literature values. A lightweight pumping station was developed to enable transport to the crater regions of Stromboli and Vulcano. The teflon membrane pump is driven by wind. The filter unit, a specially shaped quartz glass tube, was lowered into the hot vents. The temperature of the sampled fumaroles was 100 to 330 deg C. (author) 11 refs.; 4 figs.; 2 tabs

  16. The 2009 paroxysmal explosions at Stromboli (Italy): magma mixing and eruption dynamics

    Science.gov (United States)

    La Felice, Sonia; Landi, Patrizia

    2011-11-01

    Three small-scale paroxysmal explosions (also called major explosions) interrupted ordinary mild Strombolian activity at Stromboli on May 3, November 8 and 24, 2009. Products were largely confined to the summit area, except in the November 24 event, during which coarse pumiceous lapilli reached the coast. Emission of crystal-poor pumice closely mingled with crystal-rich products characterized the three events. The textural and chemical study of minerals and glassy matrices revealed that the two end-members are mingled together physically in the May 3 and November 24 pumice, whereas November 8 products contain heterogeneous glass with intermediate compositions derived from chemical mixing between crystal-rich and crystal-poor magmas. We here discuss the different degrees of interaction between the two magmas in the three explosions in terms of magma dynamics during small-scale paroxysms.

  17. Degassing, crystallization and eruption dynamics at Stromboli: trace element and lithium isotopic evidence from 2003 ashes

    Science.gov (United States)

    Schiavi, Federica; Kobayashi, Katsura; Moriguti, Takuya; Nakamura, Eizo; Pompilio, Massimo; Tiepolo, Massimo; Vannucci, Riccardo

    2010-04-01

    During its 1800-year-long persistent activity the Stromboli volcano has erupted a highly porphyritic (HP) volatile-poor scoriaceous magma and a low porphyritic (LP) volatile-rich pumiceous magma. The HP magma is erupted during normal Strombolian explosions and lava effusions, while the LP one is related to more energetic paroxysms. During the March-April 2003 explosive activity, Stromboli ejected two typologies of juvenile glassy ashes, namely highly vesicular LP shards and volatile-poor HP shards. Their textural and in situ chemical characteristics are used to unravel mutual relationships between HP and LP magmas, as well as magma dynamics within the shallow plumbing system. The mantle-normalized trace element patterns of both ash types show the typical arc-lava pattern; however, HP glasses possess incompatible element concentrations higher than LP glasses, along with Sr and Eu negative anomalies. HP shards are generally characterized by higher Li contents (to ~20 ppm) and lower δ7Li values (+1.2 to -3.8‰) with respect to LP shards (Li contents of 7-14 ppm and δ7Li ranging between +4.6 and +0.9‰). Fractional crystallization models based on major and trace element compositions, combined with a degassing model based on open-system Rayleigh distillation and on the assumption that melt/fluidDLi > 1, show that abundant (~30%) plagioclase precipitation and variable degrees of degassing can lead the more primitive LP magma to evolve toward a differentiated (isotopically lighter) HP magma ponding in the upper conduit and undergoing slow continuous degassing-induced crystallization. This study also evidences that in March 2003 Stromboli volcano poured out a small early volume of LP magma that traveled slower within the conduit with respect to later and larger volumes of fast ascending LP magma erupted during the April 5 paroxysm. The different ascent rates and cooling rates of the two LP magma batches (i.e., pre- and post-paroxysm) resulted in small, but detectable

  18. Argon systematics of neutron irradiated submarine basalt glasses from the deep south rift zone of Loihi seamount and the {sup 40}Ar/{sup 36}Ar ratio of the Hawaiian plume source

    Energy Technology Data Exchange (ETDEWEB)

    Trieloff, M.; Falter, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Jessberger, E.K. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)]|[Muenster Univ. (Germany). Inst. fuer Planetologie

    1998-12-31

    Submarine basalt glasses from Loihi seamount dredged at the southern rift zone between 3 and 5 km depth were studied. These glasses contain neon with the highest {sup 20}Ne/{sup 22}Ne ratios measured so far in submarine volcanics and constrain a well defined correlation line in a Ne-3-isotope plot (Valbracht et al., 1997). Within this study that focussed on argon isotopes an increased resolution regarding temperature and crushing steps was used: High {sup 40}Ar/{sup 36}Ar ratios at intermediate temperatures and in several crushing steps were measured which are related to argon from vesicle populations containing the most pristine mantle signature. This argon is highly improbable to be related to olivine phenocrysts and a possible contamination by MORB type noble gases. Our best constraint on the argon isotopic composition of the Loihi glasses is {sup 40}Ar/{sup 36}Ar=6590{+-}840, providing a lower limit of >5750 for the Hawaiian lower mantle source, further attesting its partially degassed nature concerning primordial noble gases. The argon distribution in the investigated Loihi glasses shows characteristic features very similar to MORB glasses. The isotopic composition of vesicle argon released by crushing covers the complete range between the atmospheric and the mantle endmember. In low vesicularity glasses mantle argon shows a nearly perfect correlation with the glass dissolved, neutron induced argon isotopes in the course of stepheating, while in glasses of higher vesicularity mantle argon partitioned into the vesicles. This is independently confirmed by the comparison of the argon yield by crushing and heating. On the other hand, the stepheating release pattern of the atmospheric component does hardly correlate with glass dissolved argon, independent on vesicularity. A significant fraction of the atmospheric contaminant is related to vesicles and pyroxene microlites, and is moreover associated with microdefects or, alternatively, is inhomogeneously distributed

  19. Lower crustal hydrothermal circulation at slow-spreading ridges: evidence from chlorine in Arctic and South Atlantic basalt glasses and melt inclusions

    Science.gov (United States)

    van der Zwan, Froukje M.; Devey, Colin W.; Hansteen, Thor H.; Almeev, Renat R.; Augustin, Nico; Frische, Matthias; Haase, Karsten M.; Basaham, Ali; Snow, Jonathan E.

    2017-12-01

    Hydrothermal circulation at slow-spreading ridges is important for cooling the newly formed lithosphere, but the depth to which it occurs is uncertain. Magmas which stagnate and partially crystallize during their rise from the mantle provide a means to constrain the depth of circulation because assimilation of hydrothermal fluids or hydrothermally altered country rock will raise their chlorine (Cl) contents. Here we present Cl concentrations in combination with chemical thermobarometry data on glassy basaltic rocks and melt inclusions from the Southern Mid-Atlantic Ridge (SMAR; 3 cm year-1 full spreading rate) and the Gakkel Ridge (max. 1.5 cm year-1 full spreading rate) in order to define the depth and extent of chlorine contamination. Basaltic glasses show Cl-contents ranging from ca. 50-430 ppm and ca. 40-700 ppm for the SMAR and Gakkel Ridge, respectively, whereas SMAR melt inclusions contain between 20 and 460 ppm Cl. Compared to elements of similar mantle incompatibility (e.g. K, Nb), Cl-excess (Cl/Nb or Cl/K higher than normal mantle values) of up to 250 ppm in glasses and melt inclusions are found in 75% of the samples from both ridges. Cl-excess is interpreted to indicate assimilation of hydrothermal brines (as opposed to bulk altered rock or seawater) based on the large range of Cl/K ratios in samples showing a limited spread in H2O contents. Resorption and disequilibrium textures of olivine, plagioclase and clinopyroxene phenocrysts and an abundance of xenocrysts and gabbroic fragments in the SMAR lavas suggest multiple generations of crystallization and assimilation of hydrothermally altered rocks that contain these brines. Calculated pressures of last equilibration based on the major element compositions of melts cannot provide reliable estimates of the depths at which this crystallization/assimilation occurred as the assimilation negates the assumption of crystallization under equilibrium conditions implicit in such calculations. Clinopyroxene

  20. Magma dynamics during the 2007 Stromboli eruption (Aeolian Islands, Italy): Mineralogical, geochemical and isotopic data

    Science.gov (United States)

    Landi, P.; Corsaro, R. A.; Francalanci, L.; Civetta, L.; Miraglia, L.; Pompilio, M.; Tesoro, R.

    2009-05-01

    After the 6 month-long effusive event of 2002-2003, a new lava effusion occurred at Stromboli between 27 February and 2 April 2007. Despite the different durations, approximately the same volume of magma was emitted in both eruptions, in the order of 10 7 m 3. A paroxysmal eruption occurred at the summit craters in both the 2002-2003 and 2007 episodes, during which a significant amount of low porphyritic (LP), volatile-rich magma was erupted. In both cases, the paroxysm did not interrupt the lava emission. Here, we present compositional data, including texture, mineralogy, chemistry and Sr and Nd isotope ratios of bulk-rock, groundmass and separated minerals of lavas erupted in 2007, together with chemistry and Sr and Nd isotope composition of the pumices emitted during the 15 March paroxysm. As a whole, the lavas have the same texture and chemistry that characterize the highly porphyritic (HP) products usually erupted at Stromboli during normal Strombolian activity and effusive events. Compared to the previous HP products, the 2007 lavas show minor but systematic mineralogical and isotopic variations which are consistent with a modest increase of the magma supply rate of the volcano. Compositional variations during the entire duration of the event are very modest. Glass chemistry changes in lavas erupted in the second half of March can be explained by the minor mixing between the volatile-rich LP magma rising through the shallow magmatic system during the 15 March paroxysm and the degassed residing HP magma. A first conclusion of this study is that there is no compositional evidence supporting major changes in the magma dynamics of the volcano accompanying the effusive activity, as also suggested for the 2002-2003 event. The activity of Stromboli is controlled by a steady state feeding system in which refilling, mixing, degassing and crystallization at shallow level continuously operate, with modest oscillations in the magma supply rate. Switching between normal

  1. Equilibration of Leachants with Basalt Rock for Repository Simulation Tests

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.

    2001-07-02

    In a nuclear waste repository in basalt, the groundwater will have a low redox potential (Eh) which may affect the leach rate of SRP waste glass. Accurate laboratory simulations of conditions in a basalt reposition must maintain low Eh values throughout the course of the experiment. In this report, important parameters affecting the ability of basalt to maintain appropriate Eh-pH conditions are examined, in particular basalt type and groundwater simulation.

  2. Lu-Hf constraints on the evolution of lunar basalts

    International Nuclear Information System (INIS)

    Fujimaki, H.; Tatsumoto, M.

    1984-01-01

    Very low Ti basalts andd green glass samples from the moon show high Lu/Hf ratios and low Hf concentrations. Low-Ti lunar basalts show high and variable Lu/Hf ratios and higher Hf concentrations, whereas high-Ti lunar basalts show low Lu/Hf ratios and high Hf concentrations. KREEP basalts have constant Lu/Hf ratios and high but variable Hf concentrations. Using the Lu-Hf behavior as a constraint, we propose a model for the mare basalts evolution. This constraint requires extensive crystallization of the primary lunar magma ocean prior to formation of the lunar mare basalt sources and the KREEP basalts. Mare basalts are produced by the melting of the cumulate rocks, and KREEP basalts represent the residual liquid of the magma ocean

  3. Glasses

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    2004-01-01

    The temperature dependence of the viscosity of most glassforming liquids is known to depart significantly from the classical Arrhenius behaviour of simple fluids. The discovery of an unexpected correlation between the extent of this departure and the Poisson ratio of the resulting glass could lead...... to new understanding of glass ageing and viscous liquid dynamics....

  4. glasses

    Indian Academy of Sciences (India)

    composed of VO5 pyramids. The vanadates-based glasses show semiconducting ..... the composition 1 mol% of CeO2. The AC conductivity obeys a power law. The glass samples exhibit typical inor- ganic semiconducting behaviour. The activation energy and conductivity at room temperature were found to be 0.09 eV ...

  5. Concurrent eruptions at Etna, Stromboli, and Vulcano: casualty or causality?

    Directory of Open Access Journals (Sweden)

    R. Funiciello

    2008-06-01

    Full Text Available Anecdotes of concurrent eruptions at Etna, Stromboli, and Vulcano (Southern Italy have persisted for more than 2000 years and volcanologists in recent and past times have hypothesized a causal link among these volcanoes. Here this hypothesis is tested. To introduce the problem and provide examples of the type of expected volcanic phenomena, narratives of the most notable examples of concurrent eruptions are provided. Then the frequency of eruptions at each individual volcano is analysed for about the last 300 years and the expected probability of concurrent eruptions is calculated to compare it to the observed probability. Results show that the occurrence of concurrent eruptions is often more frequent than a random probability, particularly for the Stromboli-Vulcano pair. These results are integrated with a statistical analysis of the earthquake catalogue to find evidence of linked seismicity in the Etnean and Aeolian areas. Results suggest a moderate incidence of non-random concurrent eruptions, but available data are temporally limited and do not allow an unequivocal identification of plausible triggers; our results, however, are the first attempt to quantify a more-than-2000-years-old curious observation and constitute a starting point for more sophisticated analyses of new data in the future. We look forward to our prediction of a moderate incidence of concurrent eruptions being confirmed or refuted with the passage of time and occurrence of new events.

  6. glasses

    Indian Academy of Sciences (India)

    materials and electrochemical batteries.8 Rare earth metal ions when added to borate act as network modifiers and change the properties of glasses. In rare earth ... room temperature to 600◦C. For electrical measurements, samples were polished and conducting silver paste was deposited on both sides. The sample area ...

  7. Implications of one-year basalt weathering/reactivity study for a basalt repository environment

    International Nuclear Information System (INIS)

    Pine, G.L.; Jantzen, C.M.

    1987-03-01

    The Savannah River Laboratory is testing the performance of the Defense Waste Processing Facility glass under conditions representing potential repository environments. For a basalt repository, one of the important issues is how rapidly reducing conditions are re-established after placement of the waste. The objective of this study was to examine the factors affecting the reactivity of the basalt. Construction of a nuclear waste repository in basalt will temporarily perturb the groundwater conditions, creating more oxidizing (air-saturated) conditions than an undisturbed repository system. Reducing conditions can be beneficial to the performance of waste glass and canisters, and may limit the transport of certain radionuclides. The Basalt Waste Isolation Project intends to use a backfill containing crushed basalt to re-establish the reducing conditions of the groundwater. The reactivity of the basalt has been found to be minimal once the fresh crushed surfaces have been weathered and the reactive intergranular glass component has been leached, e.g., by long-term surface storage. Crushing of the basalt for pneumatic emplacement of the backfill should, therefore, occur shortly before placement in the repository. This backfill must contain a minimum of 5 percent reactive fines (<100 mesh), to rapidly achieve reducing conditions. 23 refs., 21 figs., 18 tabs

  8. Glass

    OpenAIRE

    Parker, K

    2010-01-01

    Audio recording of the sea from the breakwater in Plymouth Sound, by Stuart Moore. Presentations and exhibitions of the film Glass include: Finding Place exhibition, Plymouth (3 > 26 February 2010); University of the West of England's Radical British Screens symposium (3 September 2010); Plymouth University Festival of Research: Materiality and Technology film programme presented by the Centre for Media Art and Design Research (MADr), Jill Craigie Cinema, Plymouth University (14 March 2011); ...

  9. Numerical investigation of permeability models for low viscosity magmas: Application to the 2007 Stromboli effusive eruption

    Science.gov (United States)

    La Spina, G.; Polacci, M.; Burton, M.; de'Michieli Vitturi, M.

    2017-09-01

    Magma permeability is the most important factor controlling the transition between effusive and explosive styles during magma ascent at active volcanoes. When magma permeability is low, gas bubbles in the melt expand as the pressure decreases; above a critical gas volume fraction threshold, magma fragments, generating an explosive eruption. On the contrary, if magma is sufficiently permeable, gas ascends through the conduit towards the surface faster than the magma ascent speed, producing decoupling of gas and magma and reducing the maximum vesicularity. This decoupled flow inhibits fragmentation and leads to either an effusive eruption or quiescent degassing. Accurate modelling of permeability behaviour is therefore fundamental when simulating magma ascent processes. In this work, we compare different permeability models for low viscosity magmas using a 1D steady-state model. We use, as a test case, the 2007 effusive eruption at Stromboli volcano, Italy. We compare the numerical solutions computed using the linear Darcy's law with those obtained using the non-linear Forchheimer relation. Our numerical results show that, using Darcy's law and appropriate permeability models, it is possible to obtain an effusive eruption in agreement with observations. However, we found that, in the shallow conduit, the limit of applicability of Darcy's law (that is the modified Reynolds number Rem gas flow rates. Furthermore, we show that using Forchheimer's law and some parametric expressions for viscous and inertial permeabilities, results can be compatible with an effusive eruption, once appropriate values are chosen. However, one of the parameters required to obtain an effusive eruption, the friction coefficient between gas and melt, is several orders of magnitude lower than that determined from measurements of solid erupted samples. This result requires further experimental verification. We propose that our novel permeability modelling regime is suitable for basaltic volcanism

  10. Hydrothermal evolution of repository groundwaters in basalt

    International Nuclear Information System (INIS)

    Apps, J.A.

    1984-01-01

    Groundwaters in the near field of a radioactive waste repository in basalt will change their chemical composition in response to reactions with the basalt. These reactions will be promoted by the heat generated by the decaying waste. It is important to predict both the rate and the extent of these reactions, and the secondary minerals produced, because the alteration process controls the chemical environment affecting the corrosion of the canister, the solubility and complexation of migrating radionuclides, the reactivity of the alteration products to radionuclides sorption, and the porosity and permeability of the host rock. A comprehensive review of the literature leads to the preliminary finding that hydrothermally altering basalts in geothermal regions such as Iceland lead to a secondary mineralogy and groundwater composition similar to that expected to surround a repository. Furthermore, laboratory experiments replicating the alteration conditions approximate those observed in the field and expected in a repository. Preliminary estimates were made of the rate of hydration and devitrification of basaltic glass and the zero-order dissolution rate of basaltic materials. The rates were compared with those for rhyolitic glasses and silicate minerals. Preliminary calculations made of mixed process alteration kinetics, involving pore diffusion and surface reaction suggest that at temperatures greater than 150 0 C, alteration proceeds so rapidly as to become pervasive in normally fractured basalt exposed to higher temperatures in the field. 70 references

  11. Plasma sprayed basalt/chromium oxide coatings

    Czech Academy of Sciences Publication Activity Database

    Ageorges, H.; Medarhri, Z.; Ctibor, Pavel; Fauchais, P.

    2007-01-01

    Roč. 11, č. 1 (2007), s. 71-82 ISSN 1093-3611 Institutional research plan: CEZ:AV0Z20430508 Keywords : Chromia, basalt * plasma spraying * microstructure * phase analysis Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.268, year: 2007

  12. Pyroclastic density currents at Stromboli volcano (Aeolian Islands, Italy): a case study of the 1930 eruption

    Science.gov (United States)

    Di Roberto, A.; Bertagnini, A.; Pompilio, M.; Bisson, M.

    2014-06-01

    Pyroclastic density currents (PDC) related to paroxysmal eruptions have caused a large number of casualties in the recent history of Stromboli. We combine here a critical review of historical chronicles with detailed stratigraphic, textural, and petrographic analyses of PDC deposits emplaced at Stromboli over the last century to unravel the origin of currents, their flow mechanism and the depositional dynamics. We focus on the 1930 PDC as they are well described in historical accounts and because the 1930 eruption stands as the most voluminous and destructive paroxysm of the last 13 centuries. Stromboli PDC deposits are recognizable from their architecture and the great abundance of fresh, well-preserved juvenile material. General deposit features indicate that Stromboli PDC formed due to the syn-eruptive gravitational collapse of hot pyroclasts rapidly accumulated over steep slopes. Flow channelization within the several small valleys cut on the flanks of the volcano can enhance the mobility of PDC, as well as the production of fine particles by abrasion and comminution of hot juvenile fragments, thereby increasing the degree of fluidization. Textural analyses and historical accounts also indicate that PDC can be fast (15-20 m/s) and relatively hot (360-700 °C). PDC can thus flow right down the slopes of the volcano, representing a major hazard. For this reason, they must be adequately taken into account when compiling risk maps and evaluating volcanic hazard on the Island of Stromboli.

  13. Unusually large magmatic CO2 gas emissions prior to a basaltic paroxysm

    Science.gov (United States)

    Aiuppa, Alessandro; Burton, Mike; Caltabiano, Tommaso; Giudice, Gaetano; Guerrieri, Sergio; Liuzzo, Marco; Murè, Filippo; Salerno, Giuseppe

    2010-09-01

    The low-intensity activity of basaltic volcanoes is occasionally interrupted by short-lived but energetic explosions which, whilst frequently observed, are amongst the most enigmatic volcanic events in Nature. The combination of poorly understood and deep, challenging to measure, source processes make such events currently impossible to forecast. Here we report increases in quiescent degassing CO2 emissions (>10,000 t/day) prior to a powerful explosive event on Stromboli volcano on 15 March 2007. We interpret such large CO2 flux as being sourced by passive gas leakage from a deeply (>4 km) stored magma, whose depressurization, possibly caused by the onset of an effusive eruption on 28 February 2007, was the explosion trigger. Our observations suggest that continuous CO2 flux monitoring may allow anomalously large explosions to be accurately forecast at basaltic volcanoes.

  14. High resolution seismic data coupled to Multibeam bathymetry of Stromboli island collected in the frame of the Stromboli geophysical experiment: implications with the marine geophysics and volcanology of the Aeolian Arc volcanic complex (Sicily, Southern Tyrrhenian sea, Italy).

    Science.gov (United States)

    Aiello, Gemma; Di Fiore, Vincenzo; Marsella, Ennio; Passaro, Salvatore

    2014-01-01

    New high resolution seismic data (Subbottom Chirp) coupled to high resolution Multibeam bathymetry collected in the frame of the Stromboli geophysical experiment aimed at recording active seismic data and tomography of the Stromboli Island are here presented. The Stromboli geophysical experiment has been already carried out based on onshore and offshore data acquisition in order to investigate the deep structure and the location of the magma chambers of the Stromboli volcano. A new detailed swath bathymetry of Stromboli Island is here shown and discussed to reconstruct an up-to-date morpho-bathymetry and marine geology of the area compared to the volcanologic setting of the Aeolian Arc volcanic complex. Due to its high resolution the new Digital Terrain Model of the Stromboli Island gives interesting information about the submerged structure of the volcano, particularly about the volcano-tectonic and gravitational processes involving the submarine flanks of the edifice. Several seismic units have been identified based on the geologic interpretation of Subbottom Chirp profiles recorded around the volcanic edifice and interpreted as volcanic acoustic basement pertaining to the volcano and overlying slide chaotic bodies emplaced during its complex volcano-tectonic evolution. They are related to the eruptive activity of Stromboli, mainly poliphasic and to regional geological processes involving the intriguing geology of the Aeolian Arc, a volcanic area still in activity and needing improved research interest.

  15. Vapor deposition in basaltic stalactites, Kilauea, Hawaii

    Science.gov (United States)

    Baird, A. K.; Mohrig, D. C.; Welday, E. E.

    Basaltic stalacties suspended from the ceiling of a large lava tube at Kilauea, Hawaii, have totally enclosed vesicles whose walls are covered with euhedral FeTi oxide and silicate crystals. The walls of the vesicles and the exterior surfaces of stalactites are Fe and Ti enriched and Si depleted compared to common basalt. Minerals in vesicles have surface ornamentations on crystal faces which include alkali-enriched, aluminosilicate glass(?) hemispheres. No sulfide-, chloride-, fluoride-, phosphate- or carbonate-bearing minerals are present. Minerals in the stalactites must have formed by deposition from an iron oxide-rich vapor phase produced by the partial melting and vaporization of wall rocks in the tube.

  16. Naming Lunar Mare Basalts: Quo Vadimus Redux

    Science.gov (United States)

    Ryder, G.

    1999-01-01

    Nearly a decade ago, I noted that the nomenclature of lunar mare basalts was inconsistent, complicated, and arcane. I suggested that this reflected both the limitations of our understanding of the basalts, and the piecemeal progression made in lunar science by the nature of the Apollo missions. Although the word "classification" is commonly attached to various schemes of mare basalt nomenclature, there is still no classification of mare basalts that has any fundamental grounding. We remain basically at a classification of the first kind in the terms of Shand; that is, things have names. Quoting John Stuart Mill, Shand discussed classification of the second kind: "The ends of scientific classification are best answered when the objects are formed into groups respecting which a greater number of propositions can be made, and those propositions more important than could be made respecting any other groups into which the same things could be distributed." Here I repeat some of the main contents of my discussion from a decade ago, and add a further discussion based on events of the last decade. A necessary first step of sample studies that aims to understand lunar mare basalt processes is to associate samples with one another as members of the same igneous event, such as a single eruption lava flow, or differentiation event. This has been fairly successful, and discrete suites have been identified at all mare sites, members that are eruptively related to each other but not to members of other suites. These eruptive members have been given site-specific labels, e.g., Luna24 VLT, Apollo 11 hi-K, A12 olivine basalts, and Apollo 15 Green Glass C. This is classification of the first kind, but is not a useful classification of any other kind. At a minimum, a classification is inclusive (all objects have a place) and exclusive (all objects have only one place). The answer to "How should rocks be classified?" is far from trivial, for it demands a fundamental choice about nature

  17. Hydrogen isotope systematics of submarine basalts

    Energy Technology Data Exchange (ETDEWEB)

    Kyser, T.K. (Saskatchewan Univ., Saskatoon (Canada). Dept. of Geological Sciences); O' Neil, J.R. (Geological Survey, Menlo Park, CA (USA))

    1984-10-01

    The D/H ratios and water contents in fresh submarine basalts from the Mid-Atlantic Ridge, the East Pacific Rise, and Hawaii indicate that the primary D/H ratios of many submarine lavas have been altered by processes including (1) outgassing, (2) addition of seawater at magmatic temperature, and (3) low-temperature hydration of glass. Decreases in deltaD and H/sub 2/O/sup +/ from exteriors to interiors of pillows are explained by outgassing of water whereas inverse relations between deltaD and H/sub 2/O/sup +/ in basalts from the Galapagos Rise and the FAMOUS Area are attributed to outgassing of CH/sub 4/ and H/sub 2/. A good correlation between deltaD values and H/sub 2/O is observed in a suite of submarine tholeiites dredged from the Kilauea East Rift Zone where seawater (added directly to the magma), affected only the isotopic compositions of hydrogen and argon. Analyses of some glassy rims indicate that the outer millimeter of the glass can undergo low-temperature hydration by hydroxyl groups having deltaD values as low as -100. deltaD values vary with H/sub 2/O contents of subaerial transitional basalts from Molokai, Hawaii, and subaerial alkali basalts from the Society Islands, indicating that the primary deltaD values were similar to those of submarine lavas. The results are discussed.

  18. Role for syn-eruptive plagioclase disequilibrium crystallisation in basaltic magma ascent dynamics

    Science.gov (United States)

    La Spina, Giuseppe; Burton, Mike; de'Michieli Vitturi, Mattia; Arzilli, Fabio

    2017-04-01

    Magma ascent dynamics in volcanic conduits play a key role in determining the eruptive style of a volcano. The lack of direct observations inside the conduit means that numerical conduit models, constrained with observational data, provide invaluable tools for quantitative insights into complex magma ascent dynamics. The highly nonlinear, interdependent processes involved in magma ascent dynamics require several simplifications when modelling their ascent. For example, timescales of magma ascent in conduit models are typically assumed to be much longer than crystallisation and gas exsolution for basaltic eruptions. However, it is now recognized that basaltic magmas may rise fast enough for disequilibrium processes to play a key role on the ascent dynamics. The quantification of the characteristic times for crystallisation and exsolution processes are fundamental to our understanding of such disequilibria and ascent dynamics. Using observations from Mount Etna's 2001 eruption and a magma ascent model we are able to constrain timescales for crystallisation and exsolution processes. Our results show that plagioclase reaches equilibrium in 1-2 h, whereas ascent times were 1 h. Furthermore, we have related the amount of plagioclase in erupted products with the ascent dynamics of basaltic eruptions. We find that relatively high plagioclase content requires crystallisation in a shallow reservoir, whilst a low plagioclase content reflects a disequilibrium crystallisation occurring during a fast ascent from depth to the surface. Using these new constraints on disequilibrium plagioclase crystallisation we also reproduce observed crystal abundances for different basaltic eruptions: Etna 2002/2003, Stromboli 2007 (effusive eruption) and 1930 (paroxysm) and different Pu'u' O'o eruptions at Kilauea (episodes 49-53). Therefore, our results show that disequilibrium processes play a key role on the ascent dynamics of basaltic magmas and cannot be neglected when describing basaltic

  19. Additive Construction using Basalt Regolith Fines

    Science.gov (United States)

    Mueller, Robert P.; Sibille, Laurent; Hintze, Paul E.; Lippitt, Thomas C.; Mantovani, James G.; Nugent, Matthew W.; Townsend, Ivan I.

    2014-01-01

    Planetary surfaces are often covered in regolith (crushed rock), whose geologic origin is largely basalt. The lunar surface is made of small-particulate regolith and areas of boulders located in the vicinity of craters. Regolith composition also varies with location, reflecting the local bedrock geology and the nature and efficiency of the micrometeorite-impact processes. In the lowland mare areas (suitable for habitation), the regolith is composed of small granules (20 - 100 microns average size) of mare basalt and volcanic glass. Impacting micrometeorites may cause local melting, and the formation of larger glassy particles, and this regolith may contain 10-80% glass. Studies of lunar regolith are traditionally conducted with lunar regolith simulant (reconstructed soil with compositions patterned after the lunar samples returned by Apollo). The NASA Kennedy Space Center (KSC) Granular Mechanics & Regolith Operations (GMRO) lab has identified a low fidelity but economical geo-technical simulant designated as Black Point-1 (BP-1). It was found at the site of the Arizona Desert Research and Technology Studies (RATS) analog field test site at the Black Point lava flow in adjacent basalt quarry spoil mounds. This paper summarizes activities at KSC regarding the utilization of BP-1 basalt regolith and comparative work with lunar basalt simulant JSC-1A as a building material for robotic additive construction of large structures. In an effort to reduce the import or in-situ fabrication of binder additives, we focused this work on in-situ processing of regolith for construction in a single-step process after its excavation. High-temperature melting of regolith involves techniques used in glassmaking and casting (with melts of lower density and higher viscosity than those of metals), producing basaltic glass with high durability and low abrasive wear. Most Lunar simulants melt at temperatures above 1100 C, although melt processing of terrestrial regolith at 1500 C is not

  20. Volcanic Processes, and Possible Precursors of Eruptions at Etna and Stromboli Volcanoes Revealed by Thermal Surveys

    Science.gov (United States)

    Calvari, S.

    2007-05-01

    Thermal imaging has recently been introduced in volcanology to analyze a number of different volcanic processes. This system allows us to detect magma movements within the summit conduits of volcanoes, and then to reveal volcanic activity within the craters even through the thick curtain of gases usually released by active volcanoes such as Mt Etna and Stromboli. Thermal mapping is essential during effusive eruptions, since it distinguishes lava flows of different age and concealed lava tubes' path, improving hazard evaluation. Recently, thermal imaging has also been applied to reveal failure planes and instability on the flanks of active volcanoes. Excellent results have been obtained in terms of volcanic prediction during the eruptions of Mt Etna and Stromboli occurred in 2002-2003. On Etna, thermal images monthly recorded on the summit of the volcano revealed the opening of fissure systems several months in advance. At Stromboli, helicopter-borne thermal surveys allowed us to recognize the opening of fractures one hour before the large failure that caused severe destruction on the island on 30 December 2002. The INGV - Sezione di Catania started in 2001 to monitor active volcanoes using a hand-held thermal camera. This instrument was used in field and from helicopter to detect any thermal anomaly recorded on the surface of active volcanoes, and has since been applied to a number of eruptions and eruptive processes. After the two major eruptions at Etna and Stromboli, fixed thermal cameras have been installed on Stromboli, Etna and Vulcano, allowing us to keep under control the eruptive activity, flank stability and ash emission. On Etna, we have monitored the 2002-03, 2004-05, July 2006 and August-December 2006 eruptions. On Stromboli, thermal surveys from helicopter allowed us to follow the propagation of ephemeral vents and thus the path of hidden lava tubes, as well as the stages of inflation and deflation of the upper lava flow field. Thermal cameras have

  1. Crystal Stratigraphy of Two Basalts from Apollo 16: Unique Crystallization of Picritic Basalt 606063,10-16 and Very-Low-Titanium Basalt 65703,9-13

    Science.gov (United States)

    Donohue, P. H.; Neal, C. R.; Stevens, R. E.; Zeigler, R. A.

    2014-01-01

    A geochemical survey of Apollo 16 regolith fragments found five basaltic samples from among hundreds of 2-4 mm regolith fragments of the Apollo 16 site. These included a high-Ti vitrophyric basalt (60603,10-16) and one very-low-titanium (VLT) crystalline basalt (65703,9-13). Apollo 16 was the only highlands sample return mission distant from the maria (approx. 200 km). Identification of basaltic samples at the site not from the ancient regolith breccia indicates input of material via lateral transport by post-basin impacts. The presence of basaltic rocklets and glass at the site is not unprecedented and is required to satisfy mass-balance constraints of regolith compositions. However, preliminary characterization of olivine and plagioclase crystal size distributions indicated the sample textures were distinct from other known mare basalts, and instead had affinities to impact melt textures. Impact melt textures can appear qualitatively similar to pristine basalts, and quantitative analysis is required to distinguish between the two in thin section. The crystal stratigraphy method is a powerful tool in studying of igneous systems, utilizing geochemical analyses across minerals and textural analyses of phases. In particular, trace element signatures can aid in determining the ultimate origin of these samples and variations document subtle changes occurring during their petrogenesis.

  2. The December 2002 volcanic activity at Stromboli: fall and tsunami deposits characterization

    Science.gov (United States)

    Andronico, D.; Coltelli, M.; Corsaro, R. A.; Miraglia, L.; Pompilio, M.

    2003-04-01

    The volcano of Stromboli in the Aeolian Islands (Italy) was known since the Roman age as the "lighthouse" of the Mediterranean Sea, due to its persistent "Strombolian" activity resulting in a summit firelight. During its eruptive history, Stromboli displayed effusive activity and paroxysmal eruptions, too. Lava flows usually flood down the Sciara del Fuoco, a steep depression cutting the NW flank of the cone. Paroxysmals often eject large bombs which can injure the inhabited areas and more rarely form small pyroclastic or debris flows. On the evening of 28 December 2002, effusive activity began after 17 years from the Crater 1; a lava flow reached in about 30 minutes the sea, going down the Sciara del Fuoco. On 30 December, two landslides interested a wide sector of the Sciara del Fuoco, flowing down into the sea. The first one, at about 1.15 p.m., was smaller than the second event which occurred a few minutes later and caused the detachment towards the sea of a more consistent rock volume. This events generated strong tsunami waves which affected the coastline of most of the Aeolian Islands reaching the Milazzo port, about 50 km far. Up to 10 m high waves caused severe damages to the seaside of Stromboli and to the small buildings located at Ficogrande village. We sampled the tsunami sand deposits on the beach and within the houses and the ashes emitted before, and after the tsunami event. The deposits have been studied carrying out grain-size, component analysis, morphometric and compositional characterization. The resulting data allowed to investigate magma fragmentation mechanisms and, for the first time in Stromboli, to characterize the deposit correlated to a tsunami event.

  3. Lunar Mare Basalts as Analogues for Martian Volcanic Compositions: Evidence from Visible, Near-IR, and Thermal Emission Spectroscopy

    Science.gov (United States)

    Graff, T. G.; Morris, R. V.; Christensen, P. R.

    2003-01-01

    The lunar mare basalts potentially provide a unique sample suite for understanding the nature of basalts on the martian surface. Our current knowledge of the mineralogical and chemical composition of the basaltic material on Mars comes from studies of the basaltic martian meteorites and from orbital and surface remote sensing observations. Petrographic observations of basaltic martian meteorites (e.g., Shergotty, Zagami, and EETA79001) show that the dominant phases are pyroxene (primarily pigeonite and augite), maskelynite (a diaplectic glass formed from plagioclase by shock), and olivine [1,2]. Pigeonite, a low calcium pyroxene, is generally not found in abundance in terrestrial basalts, but does often occur on the Moon [3]. Lunar samples thus provide a means to examine a variety of pigeonite-rich basalts that also have bulk elemental compositions (particularly low-Ti Apollo 15 mare basalts) that are comparable to basaltic SNC meteorites [4,5]. Furthermore, lunar basalts may be mineralogically better suited as analogues of the martian surface basalts than the basaltic martian meteorites because the plagioclase feldspar in the basaltic Martian meteorites, but not in the lunar surface basalts, is largely present as maskelynite [1,2]. Analysis of lunar mare basalts my also lead to additional endmember spectra for spectral libraries. This is particularly important analysis of martian thermal emission spectra, because the spectral library apparently contains a single pigeonite spectrum derived from a synthetic sample [6].

  4. Ash erupted during normal activity at Stromboli (Aeolian Islands, Italy) raises questions on how the feeding system works

    Science.gov (United States)

    D'Oriano, Claudia; Bertagnini, Antonella; Pompilio, Massimo

    2010-05-01

    Normal activity at Stromboli consists of continuous, non-explosive degassing, punctuated by mild explosions at a frequency of about 13 events/h. Each burst, lasting for a few seconds, throws to heights of 100-300 m incandescent scoriae, ash and blocks made of high-porphyritic (HP) degassed magma. During a multidisciplinary experiments on September 2008, ash samples emitted from 18 distinct explosions were collected with the aim of investigating magmatic and volcanic processes occurring in the conduits during the normal Strombolian activity on the basis of ash characterization. The selected samples are representative of the activity of two different craters (SW and NE) during three distinct days. After sieving, about 30 juvenile fragments (from the 0.5-1 mm size interval) were randomly hand-picked from each sample, and then mounted on double-adhesive tape on a glass slide. Single clasts were examined and photographed at the Scanning Electron Microscope (SEM) for identification of clast types, external morphology description and identification of secondary minerals. The same clasts were embedded in epoxy, sectioned and polished for textural and compositional analysis of the groundmass. Preliminary results indicate that Pele's hairs and fluidal, glassy fragments represent the majority (>50 vol%) of the juvenile material together with dense clasts (lithic clasts are less than 20 vol%. Within the juvenile fraction a minor but significant amount of highly vesicular fragments (works and raises two main questions: i) is this an occasional occurrence or is a normal feature of the persistent activity? and ii) how volatile-rich parcels of deep magma rise through a crystal-rich body without significant mixing ?

  5. The 15 March 2007 paroxysm of Stromboli: video-image analysis, and textural and compositional features of the erupted deposit

    Science.gov (United States)

    Andronico, Daniele; Taddeucci, Jacopo; Cristaldi, Antonio; Miraglia, Lucia; Scarlato, Piergiorgio; Gaeta, Mario

    2013-07-01

    On 15 March 2007, a paroxysmal event occurred within the crater terrace of Stromboli, in the Aeolian Islands (Italy). Infrared and visible video recordings from the monitoring network reveal that there was a succession of highly explosive pulses, lasting about 5 min, from at least four eruptive vents. Initially, brief jets with low apparent temperature were simultaneously erupted from the three main vent regions, becoming hotter and transitioning to bomb-rich fountaining that lasted for 14 s. Field surveys estimate the corresponding fallout deposit to have a mass of ˜1.9 × 107 kg that, coupled with the video information on eruption duration, provides a mean mass eruption rate of ˜5.4 × 105 kg/s. Textural and chemical analyses of the erupted tephra reveal unexpected complexity, with grain-size bimodality in the samples associated with the different percentages of ash types (juvenile, lithics, and crystals) that reflects almost simultaneous deposition from multiple and evolving plumes. Juvenile glass chemistry ranges from a gas-rich, low porphyricity end member (typical of other paroxysmal events) to a gas-poor high porphyricity one usually associated with low-intensity Strombolian explosions. Integration of our diverse data sets reveals that (1) the 2007 event was a paroxysmal explosion driven by a magma sharing common features with large-scale paroxysms as well as with "ordinary" Strombolian explosions; (2) initial vent opening by the release of a pressurized gas slug and subsequent rapid magma vesiculation and ejection, which were recorded both by the infrared camera and in the texture of fallout products; and (3) lesser paroxysmal events can be highly dynamic and produce surprisingly complex fallout deposits, which would be difficult to interpret from the geological record alone.

  6. Basalt Fiber for Volcanic Slag Lightweight Aggregate Concrete Research on the Impact of Performance

    Science.gov (United States)

    Xiao, Li-guang; Li, Gen-zhuang

    2018-03-01

    In order to study the effect of basalt fiber on the mechanical properties and durability of volcanic slag lightweight aggregate concrete, the experimental study on the flexural strength, compressive strength and freeze-thaw resistance of volcanic slag concrete with different basalt fiber content were carried out, the basalt fiber was surface treated with NaOH and water glass, the results show that the surface treatment of basalt fiber can significantly improve the mechanical properties, durability and other properties of volcanic slag lightweight aggregate concrete.

  7. Tra cielo e vulcano: sui confini tematici e stilistici in Stromboli di Roberto Rossellini

    Directory of Open Access Journals (Sweden)

    Vincenzo Maggitti

    2011-05-01

    Full Text Available This article is focused on a film by Roberto Rossellini, Stromboli (1949 whose title comes from the island, off the northwest coasts of Sicily, on which the film is set. Given the thematic relevance of borders in the post‐war drama of a foreign refugee who moves to the unknown island with a husband met through the barbed wire of the camp, the article analyzes to what extent this theme is rebounded in the unstable genre of the film. In Stromboli a coexistence of tropoi belonging to different traditions of melodrama can be spotted, tracing back to the theatrical origins of the genre, as detailed in Jean‐Marie Tommaseau´s recent study. But one must take into account, nevertheless, the documentary‐drive that inspires the film, linking it to Rossellini´s approach to the new unmapped reality of the Italian landscape, recently discussed by Angelo Restivo in his essay on Italian cinema during the economic boom. The interplay of these theoretical references in Stromboli can bring to the fore the theme of space and time borders as more relevant than the traditional critical filing of the film as a study of loneliness, together with the other four features made with actress Ingrid Bergman. The compounded analysis results in a melodramatic re‐vision of the film, that can entail the ending shift towards the holy and the sacred often dismissed as improper. The article comments on the film conveying melodrama into a field supposedly outside of its genre concerns.

  8. The 2007 Stromboli eruption: Event chronology and effusion rates using thermal infrared data

    Science.gov (United States)

    Calvari, S.; Lodato, L.; Steffke, A.; Cristaldi, A.; Harris, A. J. L.; Spampinato, L.; Boschi, E.

    2010-04-01

    Using thermal infrared images recorded by a permanent thermal camera network maintained on Stromboli volcano (Italy), together with satellite and helicopter-based thermal image surveys, we have compiled a chronology of the events and processes occurring before and during Stromboli's 2007 effusive eruption. These digital data also allow us to calculate the effusion rates and lava volumes erupted during the effusive episode. At the onset of the 2007 eruption, two parallel eruptive fissures developed within the northeast crater, eventually breaching the NE flank of the summit cone and extending along the eastern margin of the Sciara del Fuoco. These fed a main effusive vent at 400 m above sea level to feed lava flows that extended to the sea. The effusive eruption was punctuated, on 15 March, by a paroxysm with features similar to those of the 5 April paroxysm that occurred during the 2002-2003 effusive eruption. A total of between 3.2 × 106 and 11 × 106 m3 of lava was erupted during the 2007 eruption, over 34 days of effusive activity. More than half of this volume was emplaced during the first 5.5 days of the eruption. Although the 2007 effusive eruption had an erupted volume comparable to that of the previous (2002-2003) effusive eruption, it had a shorter duration and thus a mean output rate (=total volume divided by eruption duration) that was 1 order of magnitude higher than that of the 2002-2003 event (˜2.4 versus 0.32 ± 0.28 m3 s-1). In this paper, we discuss similarities and differences between these two effusive events and interpret the processes occurring in 2007 in terms of the recent dynamics witnessed at Stromboli.

  9. Natural analogues of nuclear waste glass corrosion

    International Nuclear Information System (INIS)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-01

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses

  10. Natural analogues of nuclear waste glass corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  11. Glass stability in the marine environment

    International Nuclear Information System (INIS)

    Zhou, Z.H.; Fyfe, W.S.; Tazaki, K.

    1987-01-01

    Similarities in corrosion behavior have been found in static leaching experiments on natural (basaltic and rhyolitic) and waste form (PNL76-68, ABS-118) glasses in seawater and marine sediments. Grainy but cohesive magnesium-rich surface layers form on both natural and waste form glasses. Basaltic and ABS-118 glasses exhibit especially similar corrosion behavior and have comparable corrosion rates. As fresh basaltic and rhyolitic glasses are common in sediments as old as Miocene (∼ 15 my) in two deep-sea drilling sites, it appears that fine natural glass can survive for a few million years. Metal encapsulated, massive glass pieces could therefore survive for millions of years if buried in appropriate marine sediments in the submarine environment. (author)

  12. Carbon Sequestration in Olivine and Basalt Powder Packed Beds.

    Science.gov (United States)

    Xiong, Wei; Wells, Rachel K; Giammar, Daniel E

    2017-02-21

    Fractures and pores in basalt could provide substantial pore volume and surface area of reactive minerals for carbonate mineral formation in geologic carbon sequestration. In many fractures solute transport will be limited to diffusion, and opposing chemical gradients that form as a result of concentration differences can lead to spatial distribution of silicate mineral dissolution and carbonate mineral precipitation. Glass tubes packed with grains of olivine or basalt with different grain sizes and compositions were used to explore the identity and spatial distribution of carbonate minerals that form in dead-end one-dimensional diffusion-limited zones that are connected to a larger reservoir of water in equilibrium with 100 bar CO 2 at 100 °C. Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt. The spatial distribution of carbonates varied between powder packed beds with different powder sizes. Packed beds of basalt powder with large specific surface areas sequestered more carbon per unit basalt mass than powder with low surface area. The spatial location and extent of carbonate mineral formation can influence the overall ability of fractured basalt to sequester carbon.

  13. Satellite and Ground Based Thermal Observation of the 2014 Effusive Eruption at Stromboli Volcano

    Directory of Open Access Journals (Sweden)

    Klemen Zakšek

    2015-12-01

    Full Text Available As specifically designed platforms are still unavailable at this point in time, lava flows are usually monitored remotely with the use of meteorological satellites. Generally, meteorological satellites have a low spatial resolution, which leads to uncertain results. This paper presents the first long term satellite monitoring of active lava flows on Stromboli volcano (August–November 2014 at high spatial resolution (160 m and relatively high temporal resolution (~3 days. These data were retrieved by the small satellite Technology Experiment Carrier-1 (TET-1, which was developed and built by the German Aerospace Center (DLR. The satellite instrument is dedicated to high temperature event monitoring. The satellite observations were accompanied by field observations conducted by thermal cameras. These provided short time lava flow dynamics and validation for satellite data. TET-1 retrieved 27 datasets over Stromboli during its effusive activity. Using the radiant density approach, TET-1 data were used to calibrate the MODVOLC data and estimate the time averaged lava discharge rate. With a mean output rate of 0.87 m3/s during the three-month-long eruption, we estimate the total erupted volume to be 7.4 × 106 m3.

  14. On the singular values decoupling in the Singular Spectrum Analysis of volcanic tremor at Stromboli

    Directory of Open Access Journals (Sweden)

    R. Carniel

    2006-01-01

    Full Text Available The well known strombolian activity at Stromboli volcano is occasionally interrupted by rarer episodes of paroxysmal activity which can lead to considerable hazard for Stromboli inhabitants and tourists. On 5 April 2003 a powerful explosion, which can be compared in size with the latest one of 1930, covered with bombs a good part of the normally tourist-accessible summit area. This explosion was not forecasted, although the island was by then effectively monitored by a dense deployment of instruments. After having tackled in a previous paper the problem of highlighting the timescale of preparation of this event, we investigate here the possibility of highlighting precursors in the volcanic tremor continuously recorded by a short period summit seismic station. We show that a promising candidate is found by examining the degree of coupling between successive singular values that result from the Singular Spectrum Analysis of the raw seismic data. We suggest therefore that possible anomalies in the time evolution of this parameter could be indicators of volcano instability to be taken into account e.g. in a bayesian eruptive scenario evaluator. Obviously, further (and possibly forward testing on other cases is needed to confirm the usefulness of this parameter.

  15. Natural analogue study of volcanic glass

    International Nuclear Information System (INIS)

    Arai, T.; Yusa, Y.; Sasaki, N.; Tsunoda, N.; Takano, H.

    1989-02-01

    A considerable range in alteration rates of basaltic glasses in various environments has been reported in previous studies. However, these studies paid only cursory attention to the environmental conditions under which the glass had been altered. In this study, the alteration of basaltic glasses was investigated and the environmental conditions and the alteration rate were discussed. Two sample ages were represented: 280 years and 2800 years. Basaltic glasses and their alteration layers were analyzed by electron probe microanalyzer (EMPA) and the thickness of the alteration layers were measured by scanning electron microscope (SEM). The ground water collected near the sampling point of Zunazawa Scoria (2800 years) and the pore water of both samples were analyzed. The alteration temperature and flow rate of water are estimated to be about 13degC and 0.2 l/cm 2 /y respectively on the basis of meteorological data. The alteration layers of young aged basaltic glasses in freshwater conditions are similar to those of leached borosilicate glasses. The alteration rates of these basaltic glasses are estimated to be several μm/1000y. The elemental concentrations in the ground water can be roughly explained as the result of leaching of the glasses. (author)

  16. Mechanical Properties of Man-Made Mineral glass fibres

    DEFF Research Database (Denmark)

    Lund, Majbritt Deichgræber; Yue, Yuanzheng

    ; man-made mineral glass fibres. The basaltic melt is prevented from crystallizing due to the high cooling rate, forming the mineral glass wool fibres. Basaltic mineral wool fibres are of high interest in industry due to their good chemical durability and excellent heat and sound insulation properties......In nature basaltic volcanic glass fibres are know from Hawaii as Pele's hair, formed by droplets of lava thrown into the air during volcanic eruption. The concept of glass fibre formation by an air stream dragging fibres from drops of melt is copied in industry to form basaltic glass wool fibres...... of the information gained from the mechanical tests, fracture characteristics of individual glass fibres are imaged by scanning electron microscopy. The fracture surfaces showed to fall in three groups; 1) surfaces including fracture mirror, mist and hackle, 2) bend fracture surfaces and 3) surfaces including pores...

  17. Investigation on mechanical properties of basalt composite fabrics (experiment study

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

    Full Text Available To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1. Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2. Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3. Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4. Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one

  18. Investigation on mechanical properties of basalt composite fabrics (experiment study)

    Science.gov (United States)

    Talebi Mazraehshahi, H.; Zamani, H.

    2010-06-01

    To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1). Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2). Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3). Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4). Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one material with

  19. Fracture and damage localization in volcanic edifice rocks from El Hierro, Stromboli and Tenerife.

    Science.gov (United States)

    Harnett, Claire E; Benson, Philip M; Rowley, Pete; Fazio, Marco

    2018-01-31

    We present elastic wave velocity and strength data from a suite of three volcanic rocks taken from the volcanic edifices of El Hierro and Tenerife (Canary Islands, Spain), and Stromboli (Aeolian Islands, Italy). These rocks span a range of porosity and are taken from volcanoes that suffer from edifice instability. We measure elastic wave velocities at known incident angles to the generated through-going fault as a function of imposed strain, and examine the effect of the damage zone on P-wave velocity. Such data are important as field measurements of elastic wave tomography are key tools for understanding volcanic regions, yet hidden fractures are likely to have a significant effect on elastic wave velocity. We then use elastic wave velocity evolution to calculate concomitant crack density evolution which ranges from 0 to 0.17: highest values were correlated to the damage zone in rocks with the highest initial porosity.

  20. Moessbauer Studies of Volhynian Basalts

    International Nuclear Information System (INIS)

    Bakun-Czubarow, N.; Milczarski, J.; Galazka-Friedman, J.; Szlachta, K.; Forder, S.

    2011-01-01

    The Volhynian basalts studied belong to the effusive-tuffogenic Volhynian Series (Slawatycze Series in Poland), being the large Ediacaran continental igneous province, that covers an area of 200 000 km 2 in the western margin of East European Craton. The series is underlain by the Cryogenian terrigenous Polesie Series with doleritic sills and dikes. The Volhynian Series consists of the rock beds belonging to the three volcanic cycles with different ratios of flood basalts to pyroclastics. The aim of the study was recognition of primary and secondary Fe-bearing minerals, particularly Fe- and Fe-Ti oxides as well as determination of iron oxidation state, that is an important tool in the search for native copper deposits in these rocks. For Moessbauer studies the following rock samples were chosen: the Polesie Series dolerites, the Volhynian Series basalts from the Ukrainian quarries and drill-holes, e.g. from the Volodymir Volhynskaya drilling hole; the Slawatycze Series basalts from Kaplonosy drill-hole in Poland. In the Kaplonosy basalts the content of magnetite decreases with depth, which may be caused by magma differentiation due to fractional crystallization, when Mg content decreases as Ti and Fe - increases in basic magma. In the Kaplonosy basalts the Fe 2+ /Fe 3+ ratio increases with depth, which points to the increase of iron oxidation with the progress of basaltic magma differentiation. (authors)

  1. Glasses, ceramics, and composites from lunar materials

    Science.gov (United States)

    Beall, George H.

    1992-02-01

    A variety of useful silicate materials can be synthesized from lunar rocks and soils. The simplest to manufacture are glasses and glass-ceramics. Glass fibers can be drawn from a variety of basaltic glasses. Glass articles formed from titania-rich basalts are capable of fine-grained internal crystallization, with resulting strength and abrasion resistance allowing their wide application in construction. Specialty glass-ceramics and fiber-reinforced composites would rely on chemical separation of magnesium silicates and aluminosilicates as well as oxides titania and alumina. Polycrystalline enstatite with induced lamellar twinning has high fracture toughness, while cordierite glass-ceramics combine excellent thermal shock resistance with high flexural strengths. If sapphire or rutile whiskers can be made, composites of even better mechanical properties are envisioned.

  2. Reference waste form, basalts, and ground water systems for waste interaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.; Ledgerwood, R.K.; Long, P.E.

    1978-09-01

    This report summarizes the type of waste form, basalt, and ground water compositions to be used in theoretical and experimental models of the geochemical environment to be simulated in studying a typical basalt repository. Waste forms to be used in the experiments include, and are limited to, glass, supercalcine, and spent unreprocessed fuel. Reference basalts selected for study include the Pomona member and the Umtanum Unit, Shwana Member, of the Columbia River Basalt Group. In addition, a sample of the Basalt International Geochemical Standard (BCR-1) will be used for cross-comparison purposes. The representative water to be used is of a sodium bicarbonate composition as determined from results of analyses of deep ground waters underlying the Hanford Site. 12 figures, 13 tables.

  3. Reference waste form, basalts, and ground water systems for waste interaction studies

    International Nuclear Information System (INIS)

    Deju, R.A.; Ledgerwood, R.K.; Long, P.E.

    1978-09-01

    This report summarizes the type of waste form, basalt, and ground water compositions to be used in theoretical and experimental models of the geochemical environment to be simulated in studying a typical basalt repository. Waste forms to be used in the experiments include, and are limited to, glass, supercalcine, and spent unreprocessed fuel. Reference basalts selected for study include the Pomona member and the Umtanum Unit, Shwana Member, of the Columbia River Basalt Group. In addition, a sample of the Basalt International Geochemical Standard (BCR-1) will be used for cross-comparison purposes. The representative water to be used is of a sodium bicarbonate composition as determined from results of analyses of deep ground waters underlying the Hanford Site. 12 figures, 13 tables

  4. Volcanic Eruption Observations from an Elevated Point of the Stromboli Using Thermal Infrared Hyperspectral Imaging

    Science.gov (United States)

    Morton, V.; Gagnon, M. A.; Marcotte, F.; Gouhier, M.; Smekens, J. F.

    2017-12-01

    Many urban areas are located near active volcanoes around the world. Therefore, scientific research on different indicators of imminent eruptions is carried out on an ongoing basis. Due to the hazardous and unpredictable behavior of volcanoes, remote sensing technologies are normally preferred for investigations. Over the years, the Telops Hyper-Cam, a high-performance infrared hyperspectral camera, has established itself as a reference tool for investigating gas clouds over large distances. In order to illustrate the benefits of standoff infrared hyperspectral imaging for characterizing volcanic processes, many different measurements were carried out from an elevated point ( 800 m) of the Stromboli volcano (Italy) by researchers from the Université Blaise-Pascal (Clermont-Ferrand, France). The Stromboli volcano is well known for its periodic eruptions of small magnitude containing various proportions of ash, lava and gases. Imaging was carried out at a relatively high spectral and spatial resolution before and during eruptions from the North-East (NE) craters. Both sulfur dioxide (SO2) and sulfur tetrafluoride (SiF4) could be successfully identified within the volcano's plume from their distinct spectral features. During the passive degassing phase, a total amount of 3.3 kg of SO2 and 0.8 g of SiF4 were estimated. A violent eruption from NE1 crater was then observed and a total of 45 g and and 7 g of SO2 and SiF4 were estimated respectively. These results are in good agreement with previous work using a UV-SO2 camera. Finally, a smaller eruption from NE2 crater was observed. Total amounts of 3 kg and 17 g of SO2 and SiF4 were estimated respectively. Quantitative chemical maps for both gases will be presented. The results show that standoff thermal infrared hyperspectral imaging provides unique insights for a better understanding of volcanic eruptions.

  5. FOAM CONCRETE REINFORCEMENT BY BASALT FIBRES

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The authors demonstrate that the foam concrete performance can be improved by dispersed reinforcement, including methods that involve basalt fibres. They address the results of the foam concrete modeling technology and assess the importance of technology-related parameters. Reinforcement efficiency criteria are also provided in the article. Dispersed reinforcement improves the plasticity of the concrete mix and reduces the settlement crack formation rate. Conventional reinforcement that involves metal laths and rods demonstrates its limited application in the production of concrete used for thermal insulation and structural purposes. Dispersed reinforcement is preferable. This technology contemplates the infusion of fibres into porous mixes. Metal, polymeric, basalt and glass fibres are used as reinforcing components. It has been identified that products reinforced by polypropylene fibres demonstrate substantial abradability and deformability rates even under the influence of minor tensile stresses due to the low adhesion strength of polypropylene in the cement matrix. The objective of the research was to develop the type of polypropylene of D500 grade that would demonstrate the operating properties similar to those of Hebel and Ytong polypropylenes. Dispersed reinforcement was performed by the basalt fibre. This project contemplates an autoclave-free technology to optimize the consumption of electricity. Dispersed reinforcement is aimed at the reduction of the block settlement in the course of hardening at early stages of their operation, the improvement of their strength and other operating properties. Reduction in the humidity rate of the mix is based on the plasticizing properties of fibres, as well as the application of the dry mineralization method. Selection of optimal parameters of the process-related technology was performed with the help of G-BAT-2011 Software, developed at Moscow State University of Civil Engineering. The authors also

  6. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior

    International Nuclear Information System (INIS)

    Techer, I.

    1999-01-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol -1 . As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r 0 , The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  7. Elaboration of vitreous and vitrocrystalline basalt materials containing simulated radioactive ash wastes. Study of some physical properties and leaching behaviour

    International Nuclear Information System (INIS)

    Lebeau, M.J.

    1988-01-01

    This work is a preliminary study of a matrix for containment of incinerator ashes. Basalt presents a good capacity for ash incorporation (up to 50%), glasses obtained are homogeneous and the low viscosity at 1300 0 C allows an industrial preparation. Vitrocrystalline products have a dendritic texture which can be controlled by cooling rate and are composed of magnesioferrite, pyroxene, plagioclase and vitreous fraction depending on the filling material ratio. Uranium and thorium, for actinide simulation in ashes, are localized in the glass. Glass leaching decrease with ash content and the alteration film presents a better retention of some elements, such as uranium and thorium. Vitrocrystalline materials are less leachable than glasses. Interesting possibilities are shown for use of basalt as filling material in underground storage, since basalt decrease glass deterioration [fr

  8. Mantle dynamics and basalt petrogenesis

    Science.gov (United States)

    Ringwood, A. E.

    1985-03-01

    Differentiation at mid-ocean ridges generates a layered lithosphere consisting of a basaltic crust, immediately underlain by harzburgite and further underlain by pyrolite which has experienced depletion only of highly incompatible elements. The body forces driving subduction are concentrated mainly in the upper half of the lithosphere which is relatively cool and brittle. During subduction, the lower layer of relatively ductile, slightly depleted pyrolite is stripped off and resorbed into the upper mantle, thereby providing a future source region for MORB magmas. The slab which sinks to ~ 600 km is comprised mainly of differentiated former basalt and harzburgite which undergo a different series of phase transformations to those experienced by mantle pyrolite. In consequence, the former basaltic crust remains denser than surrounding mantle whereas former harzburgite becomes relatively buoyant below the 650 km seismic discontinuity. The resulting non-uniformity in stress distribution causes the slab to buckle at this depth and accrete to form a large, relatively cool ovoid "megalith" of mixed former harzburgite and basaltic crust. Heating of the megalith occurs over 1-2 b.y., leading to partial melting of the former basaltic crust. The resultant liquids contaminate regions of former harzburgite, rendering them fertile in the sense of future capacity to produce basaltic magmas. After thermal equilibration, the newly fertile, former harzburgite becomes buoyant, leading to the separation of diapirs which rise into the upper mantle. Such diapirs rising beneath sub-oceanic lithosphere experience small degrees of partial melting to produce ocean island basalts, mainly of the alkaline suite. Diapirs of fertile former harzburgite rising beneath continents become incorporated into the sub-continental lithosphere. This is a cumulative process and is ultimately responsible for the development of the chemical, physical and isotopic characteristics of the sub

  9. Temporal redox variation in basaltic tephra from Surtsey volcano (Iceland)

    Science.gov (United States)

    Schipper, C. Ian; Moussallam, Yves

    2017-10-01

    The oxidation state of magma controls and/or tracks myriad petrologic phenomena, and new insights into oxidation are now made possible by high-resolution measurements of Fe3+/∑Fe in volcanic glasses. We present new μ-XANES measurements of Fe3+/∑Fe in a time series of basaltic tephra from the 1963-1967 eruption of Surtsey (Iceland), to examine if the magma mixing between alkalic and tholeiitic basalts that is apparent in the major and trace elements of these glasses is also represented in their oxidation states. Raw Fe3+/∑Fe data show a temporal trend from oxidized to reduced glasses, and this is accompanied by decreasing indices of mantle enrichment (e.g., La/Yb, Zr/Y). When expressed as composition- and temperature-corrected fO2, the trend has a similar magnitude ( 0.3 log units) to the variation in fO2 due to ridge-plume interaction along the Reykjanes Ridge. These data indicate that the oxidation state of mixed magmas can be retained through fractionation and degassing processes, and that matrix glass Fe3+/∑Fe in tephras can be used to make inferences about the relative oxidation states of parental magmas during nuanced magma mixing.

  10. Slope failures induced by the December 2002 eruption at Stromboli Volcano

    Science.gov (United States)

    Tommasi, Paolo; Baldi, Paolo; Chiocci, Francesco Latino; Coltelli, Mauro; Marsella, Maria; Romagnoli, Claudia

    We reconstruct the sequence of landslides that occurred soon after the beginning of the December 2002 eruption on the NW flank of Stromboli volcano. Landslides involved the northeastern part of the Sciara del Fuoco (SdF) slope, an old collapse scar filled by products of volcanic activity, producing tsunami waves that severely damaged the coast of the island of Stromboli. Volumes of the mass detached from the subaerial and submarine slope were quantified by comparing preslide and postslide slope surfaces obtained by aerophotogrammetric and bathymetric data, which also allowed, in conjunction with field observations and helicopter surveys, the reconstruction of geometry and kinematics of landslides. According to the reconstructed sequence, 2 days after the beginning of the eruption, the upper part of the NE sector of the SdF slope experienced major displacements (few tens of meters). Movements propagated downslope and affected the nearshore portion of the submerged slope without a rapid sliding of the displaced mass into the sea. The following hours were characterized by a progressive increase of deformations, localized along shear zones extending over two thirds of the subaerial slope. This phase proceeded until a submarine slide about 6 × 106 m3 in volume occurred, causing a first tsunami wave. The subaerial mass delimited by the shear zones and unbuttressed at its foot, then slipped into the sea producing a second tsunami wave. The main landslide event (and the minor slumps which followed) removed a volume of about 10 × 106 m3 of the infilling deposit, to a thickness of at least 65 m. Hypotheses were formulated on the mechanisms that controlled the different phases of the instability sequence. Since hydraulic and stress/strain conditions progressively changed during the slope evolution, the formulated mechanisms are also based on geotechnical analyses and considerations on the mechanical behavior of volcaniclastic materials. The process that led to the landslide

  11. Chronology of the 2007 eruption of Stromboli and the activity of the Scientific Synthesis Group

    Science.gov (United States)

    Barberi, Franco; Civetta, Lucia; Rosi, Mauro; Scandone, Roberto

    2009-05-01

    On 27 February 2007, at 12.49 GMT, a new eruption of Stromboli took place with the effusion of a lava flow from a fracture cutting the flank of the NE cone, which rapidly reached the sea. The eruption had been heralded by an increase in the amplitude of tremor and flank movement since at least the 14th of February. Short-term precursors were an increase in the rate of occurrence of small landslides within the "Sciara del Fuoco" scar on the North-western flank of the volcano. A new effusive vent opened at 18.30 GMT on the Sciara del Fuoco at an height of 400 m asl. The new lava emission caused the sudden termination of the summit flow and initiated a period of non-stationary lava outpouring which ended on 2 April, 2007. The eruption has been characterized by a rapid decrease in the eruption rate after the first days and subsequently by episodic pulse increases. On the 15th of March, the increase in lava outpouring, monitored by a thermal camera, heralded by 9 min the occurrence of a violent paroxysmal explosion with the formation of an impulsive eruption column and the emission of small pumices mingled with black scoriae. The pumice had a bulk composition similar to that of the lava and of the black scoriae, but with a distinct lower content of phenocrysts. A similar feature has been repeatedly observed during the major explosive paroxysms of Stromboli. Short term precursors of the paroxysm were recorded by strainmeter and tiltmeter stations. The volcano monitoring activity has been made by a joint team of researchers from the INGV sections of Catania, Napoli, Palermo and Rome, along with researchers from the Universities of Florence, Pisa, Roma Tre, and Palermo. The scientific activity was coordinated by a Synthesis Group made up by scientists responsible for the different monitoring techniques of INGV and Universities and by the volcanic experts of Commissione Nazionale Grandi Rischi of the Prime Minister Office (Civil Protection Department). The group made a

  12. Biologically mediated dissolution of volcanic glass in seawater

    NARCIS (Netherlands)

    Staudigel, H.; Chastain, R.A.; Yayanos, A.; Davies, G.R.; Verdurmen, E.; Schiffman, P.; Bourcier, R.; de Baar, H.

    1998-01-01

    We studied the effects of biological mediation on the dissolution of basaltic glass in seawater. Experiments with typical seawater microbial populations were contrasted with a sterile control, and reactions were monitored chemically and isotopically. Biologically mediated experiments produce twice

  13. First results from the permanent SO2 Camera system at Stromboli

    Science.gov (United States)

    Salerno, Giuseppe G.; Burton, Mike; Caltabiano, Tommaso; D'Auria, Luca; Maugeri, Roberto; Mure, Filippo

    2015-04-01

    Since the 1980's volcano monitoring has undergone stunning changes, evolving from descriptive and sparse observations to a systematic-quantitative approach of science and technology. Surveillance of chemical gas composition and their emission rate is a vital part of efforts in interpreting volcanic activity of observatories since their changes are closely linked with seismicity and deformation swings. In this unruly technology progression, volcanic gas sensing observations have also undergone a profound revolution, for example by increasing observation frequency of SO2 flux from a few samples per day to Hz. In May 2013, a permanent-robotic SO2 dual-camera system was installed by the Istituto Nazionale di Geofisica e Vulcanologia at Stromboli as a part of the ultraviolet scanning spectrometers network FLAME, with the intent to underpin the geochemical surveillance and shed light on degassing and volcanic processes. Here, we present the first results of SO2 flux observed by the permanent SO2 camera system in the period between May 2013 and April 2015. Results are corroborated with the well established FLAME ultraviolet scanning network and also compared with VLP signals from the seismic network.

  14. Porous aerosol in degassing plumes of Mt. Etna and Mt. Stromboli

    Directory of Open Access Journals (Sweden)

    V. Shcherbakov

    2016-09-01

    Full Text Available Aerosols of the volcanic degassing plumes from Mt. Etna and Mt. Stromboli were probed with in situ instruments on board the Deutsches Zentrum für Luft- und Raumfahrt research aircraft Falcon during the contrail, volcano, and cirrus experiment CONCERT in September 2011. Aerosol properties were analyzed using angular-scattering intensities and particle size distributions measured simultaneously with the Polar Nephelometer and the Forward Scattering Spectrometer probes (FSSP series 100 and 300, respectively. Aerosols of degassing plumes are characterized by low values of the asymmetry parameter (between 0.6 and 0.75; the effective diameter was within the range of 1.5–2.8 µm and the maximal diameter was lower than 20 µm. A principal component analysis applied to the Polar Nephelometer data indicates that scattering features of volcanic aerosols of different crater origins are clearly distinctive from angular-scattering intensities of cirrus and contrails. Retrievals of aerosol properties revealed that the particles were "optically spherical" and the estimated values of the real part of the refractive index are within the interval from 1.35 to 1.38. The interpretation of these results leads to the conclusion that the degassing plume aerosols were porous with air voids. Our estimates suggest that aerosol particles contained about 18 to 35 % of air voids in terms of the total volume.

  15. Paleoarchean trace fossils in altered volcanic glass.

    Science.gov (United States)

    Staudigel, Hubert; Furnes, Harald; DeWit, Maarten

    2015-06-02

    Microbial corrosion textures in volcanic glass from Cenozoic seafloor basalts and the corresponding titanite replacement microtextures in metamorphosed Paleoarchean pillow lavas have been interpreted as evidence for a deep biosphere dating back in time through the earliest periods of preserved life on earth. This interpretation has been recently challenged for Paleoarchean titanite replacement textures based on textural and geochronological data from pillow lavas in the Hooggenoeg Complex of the Barberton Greenstone Belt in South Africa. We use this controversy to explore the strengths and weaknesses of arguments made in support or rejection of the biogenicity interpretation of bioalteration trace fossils in Cenozoic basalt glasses and their putative equivalents in Paleoarchean greenstones. Our analysis suggests that biogenicity cannot be taken for granted for all titanite-based textures in metamorphosed basalt glass, but a cautious and critical evaluation of evidence suggests that biogenicity remains the most likely interpretation for previously described titanite microtextures in Paleoarchean pillow lavas.

  16. A chemical study of individual green glasses and brown glasses from 15426 - Implications for their petrogenesis

    Science.gov (United States)

    Ma, M.-S.; Liu, Y.-G.; Schmitt, R. A.

    1982-01-01

    Systematic chemical analyses of individual Apollo 15 green glasses were performed in order to: (1) study chemical variations among them; (2) understand their petrogenesis and source region; and (3) study their possible relationships with mare basalts in general. Brown glasses were also analyzed in order to study their chemical variations and their petrogenetic relationships to green glasses and mare basalts. The chemical composition of green and brown glasses is shown and variation diagrams of Sc, Cr2O3, FeO, and Co abundances in green glasses are presented. Igneous fractionation, two component magma mixing, and partial melting of heterogeneous source materials are alternate scenarios to explain strong observed correlations. The composition of green glasses indicates that they were derived by partial melting of the fractionated cumulate source materials formed from a magma ocean which had experienced certain degrees of olivine and plagioclase fractional crystallization.

  17. Detection of structural heterogeneity of glass melts

    DEFF Research Database (Denmark)

    Yue, Yuanzheng

    2004-01-01

    The structural heterogeneity of both supercooled liquid and molten states of silicate has been studied using calorimetric method. The objects of this study are basaltic glasses and liquids. Two experimental approaches are taken to detect the structural heterogeneity of the liquids. One...... is discussed. The ordered structure of glass melts above the liquidus temperature is indirectly characterized by use of X-ray diffraction method. The new approaches are of importance for monitoring the glass melting and forming process and for improving the physical properties of glasses and glass fibers....... is the hyperquench-anneal-calorimetric scan approach, by which the structural information of a basaltic supercooled liquid and three binary silicate liquids is acquired. Another is the calorimetrically repeated up- and downscanning approach, by which the structural heterogeneity, the intermediate range order...

  18. Giant Plagioclase Basalts, eruption rate versus time

    Indian Academy of Sciences (India)

    R.Narasimhan(krishtel emaging) 1461 1996 Oct 15 13:05:22

    can traps; Earth Planet. Sci. Lett. 180 13–27. Hooper P R and others 1988 The Giant Plagioclase Basalts. (GPBs) of the Western Ghats, Deccan Traps; Mem. Geol. Soc. India 43 153–65. Khadri S F R and 3 others 1988 Stratigraphy of Thakurvadi. Formation, Western Deccan Basalt Province, India: In. Deccan Flood Basalts ...

  19. Geochemical evaluation of observed changes in volcanic activity during the 2007 eruption at Stromboli (Italy)

    Science.gov (United States)

    Rizzo, A.; Grassa, F.; Inguaggiato, S.; Liotta, M.; Longo, M.; Madonia, P.; Brusca, L.; Capasso, G.; Morici, S.; Rouwet, D.; Vita, F.

    2009-05-01

    On February 27, 2007 a new eruption started at Stromboli that lasted until April 2 and included a paroxysmal explosion on March 15. Geochemical monitoring carried out over several years revealed some appreciable variations that preceded both the eruption onset and the explosion. The carbon dioxide (CO 2) flux from the soil at Pizzo Sopra La Fossa markedly increased a few days before the eruption onset, and continued during lava effusion to reach its maximum value (at 90,000 g m - 2 d - 1 ) a few days before the paroxysm. Almost contemporarily, the δ13C CO 2 of the SC5 fumarole located in the summit area increased markedly, peaking just before the explosion ( δ13C CO 2 ~ - 1.8‰). Following the paroxysm, helium (He) isotopes measured in the gases dissolved in the basal thermal aquifer sharply increased. Almost contemporarily, the automatic station of CO 2 flux recorded an anomalous degassing rate. Also temperatures and the vertical thermal gradient, which had been measured since November 2006 in the soil at Pizzo Sopra La Fossa, showed appreciable variabilities that lasted until the end of the eruption. The geochemical variations indicated the degassing of a new batch of volatile-rich magma that preceded and probably fed the paroxysm. The anomalous 3He/ 4He ratio suggested that the ascent of a second batch of volatile-rich magma toward the surface was probably responsible of the resumption of the ordinary activity. A comparison with the geochemical variations observed during the 2002-2003 eruption indicated that the 2007 eruption was less energetic.

  20. Dynamics of the shallow plumbing system investigated from borehole strainmeters and cameras, Stromboli volcano case study

    Science.gov (United States)

    Bonaccorso, Alessandro; Calvari, Sonia; Linde, Alan; Sacks, Selwyn; Boschi, Enzo

    2013-04-01

    The 15 March 2007 Vulcanian paroxysm at Stromboli volcano was recorded by several instruments that allowed describing the eruptive sequence and unravelling the processes in the upper feeding system. Among the devices installed on the island, two borehole strainmeters recorded unique signals not fully explored before. Here we present an analysis of these signals together with the time-lapse images from a monitoring system comprising both infrared and visual cameras. The two strainmeter signals display an initial phase of pressure growth in the feeding system lasting ~2 min. This is followed by 25 s of low-amplitude oscillations of the two signals, that we interpret as a strong step-like overpressure building up in the uppermost conduit by the gas-rich magma accumulating below a thick pile of rock produced by crater rim collapses. This overpressure caused shaking of the ground, and triggered a number of small landslides of the inner crater rim recorded by the monitoring cameras. When the plug obstructing the crater was removed by the initial Vulcanian blast, the two strainmeter signals showed opposite sign, compatible with a depressurizing source at ~1.5 km depth, at the junction between the intermediate and shallow feeding system inferred by previous studies. The sudden depressurization accompanying the Vulcanian blast caused an oscillation of the source composed by three cycles of about 20 sec each with a decreasing amplitude, as well recorded by the strainmeters. The visible effect of this behaviour was the initial Vulcanian blast and a 2-3 km high eruptive column followed by two lava fountainings displaying decreasing intensity and height. To our knowledge, this is the first time that such a behaviour was observed on an open conduit volcano.

  1. Il rilievo laser come tecnica di monitoraggio per i fenomeni di instabilità dei versanti degli edifici vulcanici : il caso dell'Isola di Stromboli

    Directory of Open Access Journals (Sweden)

    Maria Marsella

    2012-09-01

    ses based on the 2006 and 2009 Digital Surface Models (DSMs, generated from an Airborne Laser scanner on the Stromboli  Island  permitted  to  detect  active landslides and to extract additional information useful to hazard assessment and related mitigation actions.

  2. Flood basalts and extinction events

    Science.gov (United States)

    Stothers, Richard B.

    1993-01-01

    The largest known effusive eruptions during the Cenozoic and Mesozoic Eras, the voluminous flood basalts, have long been suspected as being associated with major extinctions of biotic species. Despite the possible errors attached to the dates in both time series of events, the significance level of the suspected correlation is found here to be 1 percent to 4 percent. Statistically, extinctions lag eruptions by a mean time interval that is indistinguishable from zero, being much less than the average residual derived from the correlation analysis. Oceanic flood basalts, however, must have had a different biological impact, which is still uncertain owing to the small number of known examples and differing physical factors. Although not all continental flood basalts can have produced major extinction events, the noncorrelating eruptions may have led to smaller marine extinction events that terminated at least some of the less catastrophically ending geologic stages. Consequently, the 26 Myr quasi-periodicity seen in major marine extinctions may be only a sampling effect, rather than a manifestation of underlying periodicity.

  3. Thermoluminescence dating of Hawaiian basalt

    Science.gov (United States)

    May, Rodd James

    1979-01-01

    The thermoluminescence (TL) properties of plagioclase separates from 11 independently dated alkalic basalts 4,500 years to 3.3 million years old and 17 tholeiitic basalts 16 years to 450,000 years old from the Hawaiian Islands were investigated for the purpose of developing a TL dating method for young volcanic rocks. Ratios of natural to artificial TL intensity, when normalized for natural radiation dose rates, were used to quantify the thermoluminescence response of individual samples for age-determination purposes. The TL ratios for the alkalic basalt plagioclase were found to increase with age at a predictable exponential rate that permits the use of the equation for the best-fit line through a plot of the TL ratios relative to known age as a TL age equation. The equation is applicable to rocks ranging in composition from basaltic andesite to trachyte over the age range from about 2,000 to at least 250,000 years before present (B.P.). The TL ages for samples older than 50,000 years have a calculated precision of less than :t 10 percent and a potential estimated accuracy relative to potassium-argon ages of approximately :t 10 percent. An attempt to develop a similar dating curve for the tholeiitic basalts was not as successful, primarily because the dose rates are on the average lower than those for the alkalic basalts by a factor of 6, resulting in lower TL intensities in the tholeiitic basalts for samples of equivalent age, and also because the age distribution of dated material is inadequate. The basic TL properties of the plagioclase from the two rock types are similar, however, and TL dating of tholeiitic basalts should eventually be feasible over the age range 10,000 to at least 200,000 years B.P. The average composition of the plagioclase separates from the alkalic basalts ranges from oligoclase to andesine; compositional variations within this range have no apparent effect on the TL ratios. The average composition of the plagioclase from the tholeiitic

  4. Ash erupted during normal activity at Stromboli (Aeolian Islands, Italy) raises questions on how the feeding system works

    Science.gov (United States)

    D'Oriano, Claudia; Bertagnini, Antonella; Pompilio, Massimo

    2011-07-01

    Ash fallout collected during 4 days of sampling at Stromboli confirms that a crystal-rich (HP) degassed magma erupts during the Strombolian explosions that are characteristic of the normal activity of this volcano. We identified 3 different types of juvenile ash fragments (fluidal, spongy and dense), which formed through different mechanisms of fragmentation of the low-viscosity, physically heterogeneous (in terms of the size and spatial distribution of bubbles) shoshonitic magma. A small amount (less than 3 vol%) of volatile-rich magma with low porphyricity (LP), erupted as highly vesicular ash fragments, has been collected, together with the HP magma, during normal strombolian explosions. Laboratory experiments and the morphological, textural and compositional investigations of ash fragments reveal that the LP ash is fresh and not recycled from the last paroxysm (15 March 2007). We suggest that small droplets of LP magma are dragged to the surface by the time-variable but persistent supply of deep derived CO2-rich gas bubbles. This coupled ascent of bubbles and LP melts is transient and does not perturb the dynamics of the HP magma within the shallow reservoir. This finding provides a new perspective on how the Stromboli volcano works and has important implications for monitoring strategies.

  5. SO 2 flux from Stromboli during the 2007 eruption: Results from the FLAME network and traverse measurements

    Science.gov (United States)

    Burton, M. R.; Caltabiano, T.; Murè, F.; Salerno, G.; Randazzo, D.

    2009-05-01

    SO 2 fluxes emitted by Stromboli during the 27th February-2nd April 2007 effusive eruption were regularly measured both by an automatic network of scanning ultraviolet spectrometers and by traverse measurements conducted by boat and helicopter. The results from both methodologies agree reasonably well, providing a validation for the automatic flux calculations produced by the network. Approximately 22,000 t of SO 2 were degassed during the course of the 35 day eruption at an average rate of 620 t per day. Such a degassing rate is much higher than that normally observed (150-200 t/d), because the cross-sectional area occupied by ascending degassed magma is much greater than normal during the effusion, as descending, degassed magma that would normally occupy a large volume of the conduit is absent. We propose that the hydrostatically controlled magma level within Stromboli's conduit is the main control on eruptive activity, and that a high effusion rate led to the depressurisation of an intermediate magma reservoir, creating a decrease in the magma level until it dropped beneath the eruptive fissure, causing the rapid end of the eruption. A significant decrease in SO 2 flux was observed prior to a paroxysm on 15th March 2007, suggesting that choking of the gas flowing in the conduit may have induced a coalescence event, and consequent rapid ascent of gas and magma that produced the explosion.

  6. Quantitative micro-Raman analysis of volcanic glasses: influence and correction of matrix effects

    Science.gov (United States)

    Di Muro, Andrea

    2014-05-01

    . Geochimica et Cosmochimica Acta, 74, 5641-5656. Mercier, M., Di Muro, A., Giordano, D., Métrich, N.,Pichavant, M., Clocchiatti, R., Montagnac, G. (2009) The influence of glass polymerization and oxidation on micro-Raman water analysis in alumino-silicate glasses. Geochimica et Cosmochimica Acta, 73, 197-217 Di Muro, A., Métrich, N., Mercier, M., Giordano, D., Massare, D., Montagnac, G. (2009) Micro-Raman determination of iron redox state in dry natural glasses : application to peralkaline rhyolites and basalts. Chemical Geology (Special volume on experimental techniques for the study of hydrothermal fluids and silicate melts) 259:78-88. Di Muro A, Villemant B, Montagnac G, Scaillet B, Reynard B (2006) The influence of glass composition on the determination of water content and speciation by Raman spectrometry. Geochimica and Cosmochimica Acta, 70, 2868-2884 Di Muro A, Giordano D., Villemant B, Montagnac G, Romano C. (2006) Influence of composition and thermal history of volcanic glasses on water content determination by microRaman spectrometry. Applied Geochemistry (Special volume on developments in analytical geochemistry). 21, 802-812. Application Di Muro, A., Staudacher, T., Ferrazzini, V., Villemant, B., Besson, P., Garofalo, C. (2014) Tracking magma injection in the Piton de la Fournaise volcanic edifice after the 2007 Summit Caldera Collapse by Pele's Hair Composition. Chapman Special Volume on Hawaiian volcanoes, AGU Books. Ardia, P., Di Muro, A., Giordano, D., Massare, D., Sanchez-Valle, C., Schmidt, M.W. (2014) Densification mechanisms of haplogranite glasses as a function of water content and pressure based on density and Raman data. Under review, submitted to Geochimica et Cosmochimica Acta. Métrich, N, Allard, P., Aiuppa, A., Bani, P., Bertagnini, A., Belhadj, O., Di Muro, A., Garaebiti, E., Massare, D., Parello, F., Shinohara, H. (2011) Magma and volatile feeding of post-caldera Yasur volcanism and block resurgence in Tanna island (Vanuatu arc). Journal of

  7. Dissolution and secondary mineral precipitation in basalts due to reactions with carbonic acid

    Science.gov (United States)

    Kanakiya, Shreya; Adam, Ludmila; Esteban, Lionel; Rowe, Michael C.; Shane, Phil

    2017-06-01

    One of the leading hydrothermal alteration processes in volcanic environments is when rock-forming minerals with high concentrations of iron, magnesium, and calcium react with CO2 and water to form carbonate minerals. This is used to the advantage of geologic sequestration of anthropogenic CO2. Here we experimentally investigate how mineral carbonation processes alter the rock microstructure due to CO2-water-rock interactions. In order to characterize these changes, CO2-water-rock alteration in Auckland Volcanic Field young basalts (less than 0.3 Ma) is studied before and after a 140 day reaction period. We investigate how whole core basalts with similar geochemistry but different porosity, permeability, pore geometry, and volcanic glass content alter due to CO2-water-rock reactions. Ankerite and aluminosilicate minerals precipitate as secondary phases in the pore space. However, rock dissolution mechanisms are found to dominate this secondary mineral precipitation resulting in an increase in porosity and decrease in rigidity of all samples. The basalt with the highest initial porosity and volcanic glass volume shows the most secondary mineral precipitation. At the same time, this sample exhibits the greatest increase in porosity and permeability, and a decrease in rock rigidity post reaction. For the measured samples, we observe a correlation between volcanic glass volume and rock porosity increase due to rock-fluid reactions. We believe this study can help understand the dynamic rock-fluid interactions when monitoring field scale CO2 sequestration projects in basalts.

  8. Strengthening of reinforced concrete beams with basalt-based FRP sheets: An analytical assessment

    International Nuclear Information System (INIS)

    Nerilli, Francesca; Vairo, Giuseppe

    2016-01-01

    In this paper the effectiveness of the flexural strengthening of RC beams through basalt fiber-reinforced sheets is investigated. The non-linear flexural response of RC beams strengthened with FRP composites applied at the traction side is described via an analytical formulation. Validation results and some comparative analyses confirm soundness and consistency of the proposed approach, and highlight the good mechanical performances (in terms of strength and ductility enhancement of the beam) produced by basalt-based reinforcements in comparison with traditional glass or carbon FRPs.

  9. Strengthening of reinforced concrete beams with basalt-based FRP sheets: An analytical assessment

    Energy Technology Data Exchange (ETDEWEB)

    Nerilli, Francesca [Unicusano - Università degli Studi Niccolò Cusano Telematica Roma, 00166 Rome (Italy); Vairo, Giuseppe [Università degli Studi di Roma “Tor Vergata”- (DICII), 00133 Rome (Italy)

    2016-06-08

    In this paper the effectiveness of the flexural strengthening of RC beams through basalt fiber-reinforced sheets is investigated. The non-linear flexural response of RC beams strengthened with FRP composites applied at the traction side is described via an analytical formulation. Validation results and some comparative analyses confirm soundness and consistency of the proposed approach, and highlight the good mechanical performances (in terms of strength and ductility enhancement of the beam) produced by basalt-based reinforcements in comparison with traditional glass or carbon FRPs.

  10. Thermodynamic model of natural, medieval and nuclear waste glass durability

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Plodinec, M.J.

    1983-01-01

    A thermodynamic model of glass durability based on hydration of structural units has been applied to natural glass, medieval window glasses, and glasses containing nuclear waste. The relative durability predicted from the calculated thermodynamics correlates directly with the experimentally observed release of structural silicon in the leaching solution in short-term laboratory tests. By choosing natural glasses and ancient glasses whose long-term performance is known, and which bracket the durability of waste glasses, the long-term stability of nuclear waste glasses can be interpolated among these materials. The current Savannah River defense waste glass formulation is as durable as natural basalt from the Hanford Reservation (10 6 years old). The thermodynamic hydration energy is shown to be related to the bond energetics of the glass. 69 references, 2 figures, 1 table

  11. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

    Science.gov (United States)

    Hudak, M. R.; Feineman, M. D.; La Femina, P. C.; Geirsson, H.

    2014-12-01

    Magmatic assimilation of felsic continental crust is a well-documented, relatively common phenomenon. The extent to which basaltic crust is assimilated by magmas, on the other hand, is not well known. Basaltic cannibalism, or the wholesale incorporation of basaltic crustal material into a basaltic magma, is thought to be uncommon because basalt requires more energy than higher silica rocks to melt. Basaltic materials that are unconsolidated, poorly crystalline, or palagonitized may be more easily ingested than fully crystallized massive basalt, thus allowing basaltic cannibalism to occur. Thrihnukagigur volcano, SW Iceland, offers a unique exposure of a buried cinder cone within its evacuated conduit, 100 m below the main vent. The unconsolidated tephra is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to a vent that produced lava and tephra during the ~4 Ka fissure eruption. Preliminary petrographic and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) analyses indicate that there are two populations of plagioclase present in the system - Population One is stubby (aspect ratio 2.1), subhedral to euhedral, and has much higher Ba/Sr ratios. Population One crystals are observed in the cinder cone, dike, and surface lavas, whereas Population Two crystals are observed only in the dike and surface lavas. This suggests that a magma crystallizing a single elongate population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the stubbier population of phenocrysts. This conceptual model for basaltic cannibalism is supported by field observations of large-scale erosion upward into the tephra, which is coated by magma flow-back indicating that magma was involved in the thermal etching. While the unique exposure at Thrihnukagigur makes it an exceptional place to investigate basaltic cannibalism, we suggest that it is not limited to this volcanic system. Rather it is a process that likely

  12. Crystallization of tholeiitic basalt in Alae Lava Lake, Hawaii

    Science.gov (United States)

    Peck, D.L.; Wright, T.L.; Moore, J.G.

    1966-01-01

    The eruption of Kilauea Volcano August 21-23, 1963, left 600,000 cubic meters of basaltic lava in a lava lake as much as 15 meters deep in Alae pit crater. Field studies of the lake began August 27 and include repeated core drilling, measurements of temperature in the crust and melt, and precise level surveys of the lake surface. The last interstitial melt in the lake solidified late in September 1964; by mid August 1965 the maximum temperature was 690??C at a depth of 11.5 meters. Pumice air-quenched from about 1140??C contains only 5 percent crystals - clinopyroxene, cuhedral olivine (Fo 80), and a trace of plagioclase, (An 70). Drill cores taken from the zone of crystallization in the lake show that olivine continued crystallizing to about 1070??C; below that it reacts with the melt, becoming corroded and mantled by pyroxene and plagioclase. Below 1070??C, pyroxene and plagioclase crystallized at a constant ratio. Ilmenite first appeared at about 1070??C and was joined by magnetite at about 1050??C; both increased rapidly in abundance to 1000??C. Apatite first appeared as minute needles in interstitial glass at 1000??C. Both the abundance and index of refraction of glass quenched from melt decreased nearly linearly with falling temperature. At 1070??C the quenched lava contains about 65 percent dark-brown glass with an index of 1.61; at 980??C it contains about 8 percent colorless glass with an index of 1.49. Below 980??C, the percentage of glass remained constant. Progressive crystallization forced exsolution of gases from the melt fraction; these formed vesicles and angular pores, causing expansion of the crystallizing lava and lifting the surface of the central part of the lake an average of 19.5 cm. The solidified basalt underwent pneumatolitic alteration, including deposition of cristobalite at 800??C, reddish alteration of olivine at 700??C, tarnishing of ilmenite at 550??C, deposition of anhydrite at 250??C, and deposition of native sulfur at 100??C

  13. Time-dependent Fisher Information Measure of volcanic tremor before the 5 April 2003 paroxysm at Stromboli volcano, Italy

    Science.gov (United States)

    Telesca, Luciano; Lovallo, Michele; Carniel, Roberto

    2010-08-01

    The investigation of the time dynamics of volcanic tremor recorded at Stromboli volcano before the paroxysm occurred on April 5, 2003 was performed, on the base of a new approach, the Fisher Information Measure (FIM), which allows to detect changes in the dynamical behavior of a complex system. The particular observed pattern suggests that the signal varies between sets of disordered states (small FIM) and sets of ordered states (large FIM). Significant precursory changes in the temporal variation of the FIM were revealed at least 42 h before the paroxysm and lasting about 17 h. The timescales highlighted are compatible to those found by other authors and could qualify the FIM as a good detector of regime changes and possible precursors of anomalous volcanic activity.

  14. Subseafloor basalts as fungal habitats

    Directory of Open Access Journals (Sweden)

    M. Ivarsson

    2012-09-01

    Full Text Available The oceanic crust is believed to host the largest potential habitat for microbial life on Earth, yet, still we lack substantial information about the abundance, diversity, and consequence of its biosphere. The last two decades have involved major research accomplishments within this field and a change in view of the ocean crust and its potential to harbour life. Here fossilised fungal colonies in subseafloor basalts are reported from three different seamounts in the Pacific Ocean. The fungal colonies consist of various characteristic structures interpreted as fungal hyphae, fruit bodies and spores. The fungal hyphae are well preserved with morphological characteristics such as hyphal walls, septa, thallic conidiogenesis, and hyphal tips with hyphal vesicles within. The fruit bodies consist of large (∼50–200 µm in diameter body-like structures with a defined outer membrane and an interior filled with calcite. The fruit bodies have at some stage been emptied of their contents of spores and filled by carbonate-forming fluids. A few fruit bodies not filled by calcite and with spores still within support this interpretation. Spore-like structures (ranging from a few µm to ∼20 µm in diameter are also observed outside of the fruit bodies and in some cases concentrated to openings in the membrane of the fruit bodies. The hyphae, fruit bodies and spores are all closely associated with a crust lining the vein walls that probably represent a mineralized biofilm. The results support a fungal presence in deep subseafloor basalts and indicate that such habitats were vital between ∼81 and 48 Ma.

  15. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  16. Tachylyte in Cenozoic basaltic lavas from the Czech Republic and Iceland: contrasting compositional trends

    Czech Academy of Sciences Publication Activity Database

    Ulrych, Jaromír; Krmíček, Lukáš; Teschner, C.; Řanda, Zdeněk; Skála, Roman; Jonášová, Šárka; Fediuk, F.; Adamovič, Jiří; Pokorný, R.

    2017-01-01

    Roč. 111, č. 5 (2017), s. 761-775 ISSN 0930-0708 Institutional support: RVO:67985831 ; RVO:61389005 Keywords : basaltic glass * chemical composition * major genetic types * mineral composition * rift-related volcanites * Sr-Nd isotopes Subject RIV: DB - Geology ; Mineralogy; CB - Analytical Chemistry, Separation (UJF-V) OBOR OECD: Mineralogy; Analytical chemistry (UJF-V) Impact factor: 1.236, year: 2016

  17. Geochemistry of sulfur isotopes in basaltic rocks

    International Nuclear Information System (INIS)

    Hubberten, H.W.; Puchelt, H.

    1980-01-01

    Sulfur isotope ratios in oceanic basalts from three different localities (Bermuda Triangle, East Pacific Rise, and Galapagos Spreading Centre and in terrestrial basalts from Saudi Arabia have been analyzed by mass spectroscopy. In order to recognize and to interpret, if possible, secondary isotopic changes of basalts, various sulfurous materials occurring together with basalts gypsum, deep thermal pyrites) have been investigated too. By mechanochemical sample preparation it was possible to determine various sulfur carriers separately. Sulfides occurring as droplets in basalts showed values of -0.4 to -0.8 0 / 00 in materials from Bermuda Triangle, Galapagos Spreading Centre, and Saudi Arabia. The values are in agreement with those suggested for primary sulfur in the earth mantle. The basalts of East Pacific Rise show a significant 34 S enrichment with a mean value of +3 0 / 00 , which may be caused by processes in the course of magmatic differentiation. Because of secondary effects sulfate sulfur, including secondary pyrite, varies considerably in its sulfur isotope ratio (delta values between -12 to +22 0 / 00 ). Samples without recognizable secondary effects have delta values of about +1.5 0 / 00 , which can be supposed for primary sulfates. Mechanically separated pyrites from deep thermal superimposed basalts show slightly negative 34 S values

  18. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  19. Applications of dynamic crystallization studies - Lunar olivine-normative basalts

    Science.gov (United States)

    Bianco, A. S.; Taylor, L. A.

    1977-01-01

    Dynamic crystallization studies were performed on two synthetic glasses similar in composition to the mare olivine-normative basalt samples 12009 and 15555. The effects of viscosity (primarily a function of FeO) and the initial temperature of cooling on mineral chemistry, texture, and temperature of appearance of phases were investigated. Olivine compositions seem to indicate that, for the two types of melt cooled at the same rate, there are no significant differences in the degree of undercooling at which olivine nucleates, but it is found that olivine-nucleated densities differ. The cooling rate of 15555 is estimated. Since the temperature at which cooling is initiated affects texture, mineral chemistry, and temperature of appearance of phases so greatly, caution is recommended in the application of experimental data to natural rock systems.

  20. Giant Plagioclase Basalts, eruption rate versus time

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 111; Issue 4. Giant Plagioclase Basalts, eruption rate versus time: Response to Sheth's comments and some additional thoughts. Gautam Sen. Volume 111 Issue 4 December 2002 pp 487-488 ...

  1. Basalt waste added to Portland cement

    Directory of Open Access Journals (Sweden)

    Thiago Melanda Mendes

    2016-08-01

    Full Text Available Portland cement is widely used as a building material and more than 4.3 billion tons were produced in 2014, with increasing environmental impacts by this industry, mainly through CO2 emissions and consumption of non-removable raw materials. Several by-products have been used as raw materials or fuels to reduce environmental impacts. Basaltic waste collected by filters was employed as a mineral mixture to Portland cement and two fractions were tested. The compression strength of mortars was measured after 7 days and Scanning Electron Microscopy (SEM and Electron Diffraction Scattering (EDS were carried out on Portland cement paste with the basaltic residue. Gains in compression strength were observed for mixtures containing 2.5 wt.% of basaltic residue. Hydration products observed on surface of basaltic particles show the nucleation effect of mineral mixtures. Clinker substitution by mineral mixtures reduces CO2 emission per ton of Portland cement.

  2. Colloidal glasses

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Colloidal glasses. Glassy state is attained when system fails to reach equilibrium due to crowding of constituent particles. In molecular glasses, glassy state is reached by rapidly lowering the temperature. In colloidal glasses, glassy state is reached by increasing the ...

  3. Constraints on ocean ridge basalt generation from Gakkel Ridge basalts

    Science.gov (United States)

    Langmuir, C. H.; Michael, P.; Standish, J.; Goldstein, S.

    2006-12-01

    The Gakkel Ridge that traverses the Arctic Ocean from Greenland to Siberia provides five "natural experiments" with respect to our understanding of melt generation and delivery at ocean ridges. (1) It is the deepest of the ocean ridges, and tests the global correlations of basalt chemistry with axial depth and the origin of such correlations. (2) It is the slowest spreading ridge, and tests the influence of ultra-slow spreading on magma generation without the complexity of oblique spreading or multiple transform offsets. (3) The samples are both on- and off-axis, allowing tests of the similarity of on- and off-axis volcanism. (4) It provides a test of the veined mantle disequilibrium melting hypothesis for MORB, since both ultra-slow spreading rate and great depth suggest minimum extents of melting, with the extent of melting decreasing progressively towards the east. (5) It tests segmentation models, because there are no transform offsets along the ridge, and the slow spreading rates should lead to maximum melt focusing along strike. The comprehensive major element, trace element and isotopic data set for the rocks obtained on the AMORE cruise allows investigation of all of these issues. (1) The Gakkel fits global depth-chemistry correlations, and major and trace element data as well as crustal thickness suggest small extents of melting in this region, decreasing towards the east. (2)Ultra-slow spreading leads to a thicker lithospheric lid and more garnet influence towards the east. The effects of thick lithosphere and mantle temperature on melting can be clearly distinguished in this region, and contrast with global systematics. This suggests that lithosphere variations are of minor importance in controlling the global array. (3) Off-axis samples are more diverse than on-axis samples, confirming the importance of off-axis volcanism at ultra-slow ridges. (4) Trace element data do not show an increase in a "veined component" towards the east as spreading rate

  4. First gas flux measurements of conduit permeability decrease prior to Strombolian eruption at Stromboli volcano (Italy)

    Science.gov (United States)

    Tamburello, Giancarlo; Aiuppa, Alessandro; Lo Coco, Eleonora; Delle Donne, Dario; Ripepe, Maurizio; Bitetto, Marcello; D'Aleo, Roberto

    2016-04-01

    Strombolian eruptions can be described in terms of growth, coalescence, and rise of a gas pocket (aka slug) bursting at the surface of a vent. This model overlooks that the transition to explosive regimes is mostly controlled by the permeability in the upper part of a volcanic conduit. We report here on the first gas flux measurements of Strombolian explosions from a vent that exhibited a significant decrease of passive degassing tens of second prior to the onset of the explosion. This particular explosive activity took place during the July 2014 lava overflows, when the magma level inside the conduit rose up to the crater terrace. The amount of gas that accumulated before the eruption is incredibly similar to the amount of gas ejected during the explosion. This similarity suggests a mechanism of decrease of the shallow conduit permeability and a subsequent accumulation of gas behind a cap of cold magma. The accumulated gas is then released when the over-pressure can open a leak on the cap of cold magma. Our unprecedented results offer key and novel insights into the explosive degassing dynamics within the shallow conduit systems of this open-vent volcano and probably at many other basaltic volcanoes.

  5. Decrypting geophysical signals at Stromboli Volcano (Italy): Integration of seismic and Ground-Based InSAR displacement data.

    Science.gov (United States)

    Di Traglia, F; Cauchie, L; Casagli, N; Saccorotti, G

    2014-04-28

    We present the integration of seismic and Ground-Based Interferometric Synthetic Aperture Radar system (GBInSAR) displacement data at Stromboli Volcano. Ground deformation in the area of summit vents is positively correlated with both seismic tremor amplitude and cumulative amplitudes of very long period (VLP) signals associated with Strombolian explosions. Changes in VLP amplitudes precede by a few days the variations in ground deformation and seismic tremor. We propose a model where the arrival of fresh, gas-rich magma from depth enhances gas slug formation, promoting convection and gas transfer throughout the conduit system. At the shallowest portion of the conduit, an increase in volatile content causes a density decrease, expansion of the magmatic column and augmented degassing activity, which respectively induce inflation of the conduit, and increased tremor amplitudes. The temporal delay between increase of VLP and tremor amplitudes/conduit inflation can be interpreted in terms of the different timescales characterizing bulk gas transfer versus slug formation and ascent.

  6. Silicate glasses

    International Nuclear Information System (INIS)

    Lutze, W.

    1988-01-01

    Vitrification of liquid high-level radioactive wastes has received the greatest attention, world-wide, compared to any other HLW solidification process. The waste form is a borosilicate-based glass. The production of phosphate-based glass has been abandoned in the western world. Only in the Soviet Union are phosphate-based glasses still being developed. Vitrification techniques, equipment and processes and their remote operation have been developed and studied for almost thirty years and have reached a high degree of technical maturity. Industrial demonstration of the vitrification process has been in progress since 1978. This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e., borosilicate glasses

  7. Effect of Fluorine on Near-Liquidus Phase Equilibria of Basalts

    Science.gov (United States)

    Filiberto, Justin; Wood, Justin; Loan, Le; Dasgupta, Rajdeep; Shimizu, Nobumichi; Treiman, Allan H.

    2010-01-01

    Volatile species such as H2O, CO2, F, and Cl have significant impact in generation and differentiation of basaltic melts. Thus far experimental work has primarily focused on the effect of water and carbon dioxide on basalt crystallization, liquid-line of descent, and mantle melting [e.g., 1, 2] and the effects of halogens have received far less attention [3-4]. However, melts in the planetary interiors can have non-negligible chlorine and fluorine concentrations. Here, we explore the effects of fluorine on near-liquidus phase equilibria of basalt. We have conducted nominally anhydrous piston cylinder experiments using graphite capsules at 0.6 - 1.5 GPa on an Fe-rich model basalt composition. 1.75 wt% fluorine was added to the starting mix in the form of AgF2. Fluorine in the experimental glass was measured by SIMS and major elements of glass and minerals were analyzed by EPMA. Nominally volatile free experiments yield a liquidus temperature from 1330 C at 0.8GPa to 1400 at 1.6GPa and an olivine(Fo72)-pyroxene(En68)-liquid multiple saturation point at 1.25 GPa and 1375 C. The F-bearing experiments yield a liquiudus temperature from 1260 C at 0.6GPa to 1305 at 1.5GPa and an ol(Fo66)-pyx(En64)-MSP at 1 GPa and 1260 C. This shows that F depresses the basalt liquidus, extends the pyroxene stability field to lower pressure, and forces the liquidus phases to be more Fe-rich. KD(Fe-Mg/mineral-melt) calculated for both pyroxenes and olivines show an increase with increasing F content of the melt. Therefore, we infer that F complexes with Mg in the melt and thus increases the melt s silica activity, depressing the liquidus and changing the composition of the crystallizing minerals. Our study demonstrates that on a weight percent basis, the effect of fluorine is similar to the effect of H2O [1] and Cl [3] on freezing point depression of basalts. But on an atomic fraction basis, the effect of F on liquidus depression of basalts is xxxx compared to the effect of H. Future

  8. Studies of Magmatic Inclusions in the Basaltic Martian Meteorites Shergotty, Zagami, EETA 79001 and QUE 94201

    Science.gov (United States)

    Harvey, Ralph P.; McKay, Gordon A.

    1997-01-01

    Currently there are 12 meteorites thought by planetary scientists to be martian samples, delivered to the Earth after violent impacts on that planet's surface. Of these 12 specimens, 4 are basaltic: Shergotty, Zagami, EETA 79001 and QUE 94201. Basalts are particularly important rocks to planetary geologists- they are the most common rocks found on the surfaces of the terrestrial planets, representing volcanic activity of their parent worlds. In addition, because they are generated by partial melting of the mantle and/or lower crust, they can serve as guide posts to the composition and internal processes of a planet. Consequently these four meteorites can serve as 'ground-truth' representatives of the predominant volcanic surface rocks of Mars, and offer researchers a glimpse of the magmatic history of that planet. Unfortunately, unraveling the parentage of a basaltic rock is not always straightforward. While many basalts are simple, unaltered partial melts of the mantle, others have undergone secondary processes which change the original parental chemistry, such as assimilation of other crustal rocks, mixing with other magmas, accumulation, re-equilibration between mineral species after crystallization, loss of late-stage magmatic fluids and alteration by metamorphic or metasomatic processes. Fortunately, magmatic inclusions can trap the evolving magmatic liquid, isolating it from many of these secondary processes and offering a direct look at the magma during different stages of development. These inclusions form when major or minor phases grow skeletally, surrounding small amounts of the parental magma within pockets in the growing crystal. The inclusion as a whole (usually consisting of glass with enclosed crystals) continues to represent the composition of the parental magma at the time the melt pocket closed, even when the rock as a whole evolves under changing conditions. The four basaltic martian meteorites contain several distinct generations of melt

  9. Multiphase Alkaline Basalts of Central Al-Haruj Al-Abyad of Libya: Petrological and Geochemical Aspects

    Directory of Open Access Journals (Sweden)

    Abdel-Aal M. Abdel-Karim

    2013-01-01

    Full Text Available Al-Haruj basalts that represent the largest volcanic province in Libya consist of four lava flow phases of varying thicknesses, extensions, and dating. Their eruption is generally controlled by the larger Afro-Arabian rift system. The flow phases range from olivine rich and/or olivine dolerites to olivine and/or normal basalts that consist mainly of variable olivine, clinopyroxene, plagioclase, and glass. Olivine, plagioclase, and clinopyroxene form abundant porphyritic crystals. In olivine-rich basalt and olivine basalt, these minerals occur as glomerophyric or seriate clusters of an individual mineral or group of minerals. Groundmass textures are variably intergranular, intersertal, vitrophyric, and flow. The pyroclastic, clastogenic flows and/or ejecta of the volcanic cones show porphyritic, vitrophric, pilotaxitic, and vesicular textures. They are classified into tholeiite, alkaline, and olivine basalts. Three main groups are recorded. Basalts of phase 1 are generated from tholeiitic to alkaline magma, while those of phases 3 and 4 are derived from alkaline magma. It is proposed that the tholeiitic basalts represent prerift stage magma generated by higher degree of partial melting (2.0–3.5% of garnet-peridotite asthenospheric mantle source, at shallow depth, whereas the dominant alkaline basalts may represent the rift stage magma formed by low degree of partial melting (0.7–1.5% and high fractionation of the same source, at greater depth in an intra-continental plate with OIB affinity. The melt generation could be also attributed to lithosphere extension associated with passive rise of variable enriched mantle.

  10. Can we identify source lithology of basalt?

    Science.gov (United States)

    Yang, Zong-Feng; Zhou, Jun-Hong

    2013-01-01

    The nature of source rocks of basaltic magmas plays a fundamental role in understanding the composition, structure and evolution of the solid earth. However, identification of source lithology of basalts remains uncertainty. Using a parameterization of multi-decadal melting experiments on a variety of peridotite and pyroxenite, we show here that a parameter called FC3MS value (FeO/CaO-3*MgO/SiO2, all in wt%) can identify most pyroxenite-derived basalts. The continental oceanic island basalt-like volcanic rocks (MgO>7.5%) (C-OIB) in eastern China and Mongolia are too high in the FC3MS value to be derived from peridotite source. The majority of the C-OIB in phase diagrams are equilibrium with garnet and clinopyroxene, indicating that garnet pyroxenite is the dominant source lithology. Our results demonstrate that many reputed evolved low magnesian C-OIBs in fact represent primary pyroxenite melts, suggesting that many previous geological and petrological interpretations of basalts based on the single peridotite model need to be reconsidered.

  11. The 2007 eruption of Stromboli volcano: Insights from real-time measurement of the volcanic gas plume CO 2/SO 2 ratio

    Science.gov (United States)

    Aiuppa, Alessandro; Federico, Cinzia; Giudice, Gaetano; Giuffrida, Giovanni; Guida, Roberto; Gurrieri, Sergio; Liuzzo, Marco; Moretti, Roberto; Papale, Paolo

    2009-05-01

    The recent eruption of Stromboli in February-April 2007 offered a unique chance to test our current understanding of processes driving the transition from ordinary (persistent Strombolian) to effusive activity, and the ability of instrumental geophysical and geochemical networks to interpret and predict these events. Here, we report on the results of two years of in-situ sensing of the CO 2/SO 2 ratio in Stromboli's volcanic gas plume, in the attempt to put constraints on the trigger mechanisms and dynamics of the eruption. We show that large variations of the plume CO 2/SO 2 ratio (range, 0.9-26) preceded the onset of the eruption (since December 2007), interrupting a period of relatively-steady and low ratios (time-averaged ratio, 4.3) lasting from at least May to November 2006. By contrasting our observations with numerical simulations of volcanic degassing at Stromboli, derived by use of an equilibrium saturation model, we suggest that the pre-eruptive increase of the ratio reflected an enhanced supply of deeply-derived CO 2-rich gas bubbles to the shallow-plumbing system. This larger-than-normal ascent of gas bubbles was likely sourced by a 1-3 km deep gas-melt separation region (probably a magma storage zone), and caused faster convective overturning of magmas in the shallow conduit; an increase in the explosive rate and in seismic tremor, and finally the collapse of the la Sciara del Fuoco sector triggering the effusive phase. The high CO 2/SO 2 ratios (up to 21) observed during the effusive phase, and particularly in the days and hours before a paroxysmal explosion on March 15, 2007, indicate the persistence of the same gas source; and suggest that de-pressurization of the same 1-3 km deep magma storage zone could have been the trigger mechanism for the paroxysm itself.

  12. Oxygen Fugacity of Mare Basalts and the Lunar Mantle Application of a New Microscale Oxybarometer Based on the Valence State of Vanadium

    Science.gov (United States)

    Shearer, C. K.; Karner, J.; Papike, J. J.; Sutton, S. R.

    2004-01-01

    The ability to estimate oxygen fugacities for mare basalts and to extend these observations to the lunar mantle is limited using bulk analysis techniques based on buffering assemblages or the valence state of iron. These limitations are due to reequilibration of mineral assemblages at subsolidus conditions, deviations of mineral compositions from thermodynamic ideality, size requirements, and the limits of the iron valence at very low fO2. Still, these approaches have been helpful and indicate that mare basalts crystallized at fO2 between the iron-w stite buffer (IW) and the ilmenite breakdown reaction (ilmenite = rutile + iron). It has also been inferred from these estimates that the lunar mantle is also highly reduced lying at conditions below IW. Generally, these data cannot be used to determine if the mare basalts become increasingly reduced during transport from their mantle source and eruption at the lunar surface and if there are differences in fO2 among mare basalts or mantle sources. One promising approach to determining the fO2 of mare basalts is using the mean valence of vanadium (2+, 3+, 4+, 5+) determined on spots of a few micrometers in diameter using synchrotron x-ray absorption fine structure (XAFS) spectroscopy. The average valence state of V in basaltic glasses is a function of fO2, temperature, V coordination, and melt composition. Here, we report the initial results of this approach applied to lunar pyroclastic glasses.

  13. Experimental alterations on ceramic interest basalts

    International Nuclear Information System (INIS)

    Sanfeliu-Montolio, T.; Ballbe-Lonch, E.; Querlat-Mitjans, I.; Juan-Abril, A.; Fuente-Cellell, C. de la

    1991-01-01

    This study presents the results and conclusion extracted of the chemical and mineralogical analysis made on 12 samples of recent and subrecent (IV series) Canary Island's basalt, that have been subject to different attack processes in order to cause in them controlled mineralogical alterations. The methods used were: optical analysis, x-ray fluorescence analysis and x-ray diffraction. The object of this work is to determine the alterability of these basaltic rocks that have ceramic interest since it's possible its use in same ceramic manufactures and also as petrurgic raw material. (author)

  14. The genesis and evolution of Hannuoba Basalt based on the Xiaomaping basalt profile

    Science.gov (United States)

    Huixin, Hei; Shangguo, Su; Yu, Wang

    2014-05-01

    Hannuoba basalt lies in the northern of North China. It erupted in Cenozoic with well outcrops and widespread ultramafic xenoliths. This study focuses on the Xiaomaping basalt profile in Hannuoba district. The profile can be distinguished for 7 layers with each bottom of the layer enriched with ultramafic xenoliths. In the Hark polt, all major elements have good correlation with the MgO content, showing the basalt from different layers having an consistent evolution. The phenocrysts in the basalt from different layers are rare and mostly within 5% with main faces as Ol, Cpx and Opx. The chemical characteristic of the basalt shows mutative features, Mg# (52.0-67.7), CaO (7.3-8.5wt. %), Ni (82-192ppm) and Cr (65-192ppm). The basalts have apparent LREE enrichment and are rich in HFSE (Nb,Ta,Zr) and in LILE (Ba, Sr). All the basalt layers do not show manifest negative Eu with δEu=1.01-1.05. The ultramafic xenoliths are spinel-lherzolite, with weak lack of LREE. Trace element ratios, Ba / Rb and Rb / Sr, show that the source might have experienced some extent of fluid metasomatism. According to the La and La/Sm plot, the basalts are mainly controlled by the partial melting, and the great extent of fractional crystallization did not happened during the evolution process. Based on current published experimental results and theoretical petrology analysis, Hannuoba basalts formed in equilibrium with pyroxenite with clinopyroxene and garnet as the main mineral faces in the source and accounting olivine in small extent.

  15. Recycle Glass in Foam Glass Production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  16. Cosmos & Glass

    DEFF Research Database (Denmark)

    Beim, Anne

    1996-01-01

    The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne.......The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne....

  17. Halogen and trace element geochemistry in Mid-Ocean Ridge basalts from the Australian-Antarctic Ridge (AAR)

    Science.gov (United States)

    Yang, Y. S.; Seo, J. H.; Park, S. H.; Kim, T.

    2015-12-01

    Australian-Antarctic Ridge (AAR) is an extension of easternmost SE Indian Mid-Ocean Ridge (MOR).We collected volcanic glasses from the "in-axis" of the KR1 and KR2 MOR, and the overlapping zones of the KR1 MOR and the nearby seamounts ("KR1 mixing"). We determined trace and halogen elements in the glasses. Halogen concentrations and its ratios in the glasses are important to understand the mantle metasomatism and volatile recycling. 52 of the collected glasses are "primitive" (higher than 6 wt% MgO), while 3 of them have rather "evolved" composition (MgO wt% of 1.72, 2.95 and 4.15). K2O concentrations and Th/Sc ratios in the glasses show a negative correlation with its MgO concentration. Incompatible element ratios such as La/Sm are rather immobile during a magma differentiation so the ratios are important to understand mantle composition (Hofmann et al. 2003). La/Sm ratios in the glasses are 0.95 ~ 3.28 suggesting that the AAR basalts can be classified into T-MORB and E-MORB (Schilling et al., 1983). La/Sm ratios are well-correlated with incompatible elements such as U, Ba, Nb, and negatively correlated with compatible elements such as Sc, Eu2+, Mg. The AAR glasses contain detectable halogen elements. The "KR1 mixing" glasses in halogen elements are more abundant than "in-axis" the glasses. Cl is the least variable element compared to the other halogens such as Br and I in the AAR. The "KR1 mixing" glasses have the largest variations of Br/Cl ratios compared to the "in-axis" glasses. The Cl/Br and Th/Sc ratios in the "in-axis" glasses and in the "KR1 mixing" glasses show positive and negative correlations, respectively. The Br-rich glasses in the "KR1 mixing" zone might be explained by a recycled Br-rich oceanic slab of paleo-subduction or by a hydrothermal alteration in the AAR. I composition in the glasses does not show a correlation other trace elements. The K/Cl and K/Ti ratios in the AAR glasses are similar to the basalts from the Galapagos Spreading Center

  18. Evaluation of thermobarometry for spinel lherzolite fragments in alkali basalts

    Science.gov (United States)

    Ozawa, Kazuhito; Youbi, Nasrrddine; Boumehdi, Moulay Ahmed; McKenzie, Dan; Nagahara, Hiroko

    2017-04-01

    various method of estimation of ascent rate of mantle fragments in kimberlite and alkali basalt; one based on fluid dynamics of transportation of entrapped fragments by giving the maximum size and viscosity of magma as a minimum estimate (Spera, 1980) and the other by coupling depth of fragment residence before the entrapment in a magma and time scale of heating by the magma. The depth of entrapment, however, is the least known parameter for spinel lherzolite. Because of nearly adiabatic ascent of magmas loaded with solid fragments, all the fragments underwent the same heating and decompression history with difference in entrapment depth and thus heating duration, from which the depth of their residence just before the extraction may be estimated if ascent rate is known. Therefore, extent of chemical and textural modification induced by heating and decompression may provide independent test for pressure estimation. We have used several reactions for this purpose: (1) Mg-Fe exchange reaction between spinel and olivine (Ozawa, 1983; 1984), (2) Ca zoning in olivine (Takahashi, 1980), (3) partial dissolution of clinopyroxene, (4) partial dissolution of spinel, and (5) formation of melt frozen as glass, which is related to (3) and (4). The depth of melt generation is constrained to be deeper than 70km by modeling the trace element compositions of the host magmas using the methods of McKenzie and O'Nions (1991) and data from El Azzouzi et al. (2010). The host magmas can be produced by melting the convecting upper mantle without requirement of any input from the continental lithosphere. This is consistent with the positive gravity anomalies in the NW Africa showing shallow upwelling in this region allowing decompressional melting owing to the thinner lithosphere in the Middle Atlas.

  19. Application of a new multiphase multicomponent volcanic conduit model with magma degassing and crystallization to Stromboli volcano.

    Science.gov (United States)

    La Spina, Giuseppe; Burton, Mike; de'Michieli Vitturi, Mattia

    2014-05-01

    reproduce both effusive and explosive eruptive activities at Stromboli volcano. Three different crystal components (olivine, pyroxene and feldspar) and two different gas species (water and carbon dioxide) are taken into account. The equilibrium profiles of crystallization as function of pressure, temperature and water content are modeled using the numerical codes AlphaMELTS and DAKOTA. The equilibrium of dissolved gas content, instead, is obtained using a non-linear fitting of data computed using VolatileCALC. With these data, we simulate numerically the lava effusion that occurred at Stromboli between 27 February and 2 April 2007, and find good agreement with the observed data (vesicularity, exsolved gas composition, crystal content and mass flow rate) at the vent. We find that the model is highly sensitive to input magma temperature, going from effusive to explosive eruption with temperature changes by just 20 °C. We thoroughly investigated through a sensitivity analysis the control of the temperature of magma chamber and of the radius of the conduit on the mass flow rate, obtaining also a set of admissible temperatures and conduit radii that produce results in agreement with the real observations.

  20. Development of a 3D numerical model to evaluate the Stromboli NW flank instability in relation to magma intrusion

    Science.gov (United States)

    Apuani, T.; Merri, A.

    2009-04-01

    A stress-strain analysis of the Stromboli volcano was performed using a three-dimensional explicit finite difference numerical code (FLAC 3D, ITASCA, 2005), to evaluate the effects associated to the presence of magma pressure in magmatic conduit and to foresee the evolution of the magmatic feeding complex. The simulations considered both the ordinary state for the Stromboli, characterized by a partial fill of the active dyke with regular emission of gas and lava fountains and the paroxysmal conditions observed during the March 2007's eruptive crisis, with the magma level in the active dyke reaching the topographic surface along the Sciara del Fuoco depression. The modeling contributes to identify the most probable directions of propagation of new dikes, and the effects of their propagation on the stability of the volcano edifice. The numerical model extends 6 x 6 x 2.6 km3, with a mesh resolution of 100 m, adjusting the grid to fit the shape of the object to be modeled. An elasto-plastic constitutive law was adopted and an homogeneous Mohr-Coulomb strength criterion was chosen for the volcanic cone, assuming one lithotechnical unit (alternation of lava and breccia layers "lava-breccia unit"- Apuani et al 2005). The dykes are represented as discontinuities of the grid, and are modeled by means of interfaces. The magmatic pressure is imposed to the model as normal pressure applied on both sides of the interfaces. The magmastatic pressure was calculated as Pm=d•h, where d is the magma unit weight assumed equal to 25 KN/m3, and h (m) is the height of the magma column. Values of overpressure between 0 and 1 MPa were added to simulate the paroxysmal eruption. The simulation was implemented in successive stages, assuming the results of the previous stages as condition for the next one. A progressive propagation of the dike was simulated, in accordance with the stress conditions identified step by step, and in accordance with the evidences detected by in situ survey, and

  1. Petrography of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Petrographic characteristics of basalts collected from a segment of the Carlsberg Ridge (lat. 3 degrees 35'N to 3 degrees 41'N; long. 64 degrees 05'E to 64 degrees 09'E) show typical pillow lava zonations with variable concentrations of plagioclase...

  2. Basalt: structural insight as a construction material

    Indian Academy of Sciences (India)

    This paper explores the state of the art of basalt used in the construction industry with the overall layout of different subcategories of historical background starting from fibre development and different chemical and mechanical fibre properties to its applications in the field. Comparative studies have also been reported with ...

  3. Thermal models for basaltic volcanism on Io

    Science.gov (United States)

    Keszthelyil, L.; McEwen, A.

    1997-01-01

    We present a new model for the thermal emissions from active basaltic eruptions on Io. While our methodology shares many similarities with previous work, it is significantly different in that (1) it uses a field tested cooling model and (2) the model is more applicable to pahoehoe flows and lava lakes than fountain-fed, channelized, 'a'a flows. This model demonstrates the large effect lava porosity has on the surface cooling rate (with denser flows cooling more slowly) and provides a preliminary tool for examining some of the hot spots on Io. The model infrared signature of a basaltic eruption is largely controlled by a single parameter, ??, the average survival time for a lava surface. During an active eruption surfaces are quickly covered or otherwise destroyed and typical values of ?? for a basaltic eruption are expected to be on the order of 10 seconds to 10 minutes. Our model suggests that the Galileo SSI eclipse data are consistent with moderately active to quiescent basaltic lava lakes but are not diagnostic of such activity. Copyright 1997 by the American Geophysical Union.

  4. Pressure grouting of fractured basalt flows

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, P.; Weidner, J.; Phillips, S.; Alexander, J.

    1996-04-01

    This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material.

  5. Increased corrosion resistance of basalt reinforced cement compositions with nanosilica

    Directory of Open Access Journals (Sweden)

    URKHANOVA Larisa Alekseevna

    2014-08-01

    Full Text Available Disperse fiber reinforcement is used to improve deformation and shrinkage characteristics, flexural strength of concrete. Basalt roving and thin staple fiber are often used as mineral fibers. The paper considers the problems of using thin basalt fiber produced by centrifugal-blow method. Evaluation of the corrosion resistance of basalt fiber as part of the cement matrix was performed. Nanodispersed silica produced by electron beam accelerator was used to increase corrosion resistance of basalt fiber.

  6. Tachylyte in Cenozoic basaltic lavas from the Czech Republic and Iceland: contrasting compositional trends

    Science.gov (United States)

    Ulrych, Jaromír; Krmíček, Lukáš; Teschner, Claudia; Řanda, Zdeněk; Skála, Roman; Jonášová, Šárka; Fediuk, Ferry; Adamovič, Jiří; Pokorný, Richard

    2017-10-01

    Tachylytes from rift-related volcanic rocks were recognized as: (i) irregular veinlets in host alkaline lava flows of the Kozákov volcano, Czech Republic, (ii) (sub)angular xenoliths in alkaline lava of the feeding channel of the Bukovec volcano, Czech Republic, and (iii) paleosurface of a tholeiitic lava flow from Hafrafell, Iceland. The tachylyte from Kozákov is phonotephrite to tephriphonolite in composition while that from Bukovec corresponds to trachyandesite to tephriphonolite. Both glass and host rock from Hafrafell are of tholeiitic basalt composition. The tachylyte from Kozákov, compared with the host rock, revealed a substantial enrichment in major elements such as Si, Al and alkalis along with Rb, Sr, Ba, Nb, Zr, REE, Th and U. The tachylyte from Bukovec displays contrasting trends in the incompatible element contents. The similarity in composition of the Hafrafell tachylyte paleosurface layer and parental tholeiitic basalt is characteristic for lavas. The host/parent rocks and tachylytes have similar initial Sr-Nd characteristics testifying for their co-magmatic sources. The initial ɛNd values of host/parent rocks and tachylytes from the Bohemian Massif (+3.4 to +3.9) and those from Iceland (+6.3) are interpreted as primary magma values. Only the tachylyte from Bukovec shows a different ɛNd value of -2.1, corresponding to a xenolith of primarily sedimentary/metamorphic origin. The tachylyte from Kozákov is a product of an additional late magmatic portion of fluids penetrating through an irregular fissure system of basaltic lava. The Bukovec tachylyte is represented by xenoliths originated during the interaction of ascending basaltic melt with granitoids or orthogneisses, whereas the Hafrafell tachylyte is a product of a rapid cooling on the surface of a basalt flow.

  7. Glass Glimpsed

    DEFF Research Database (Denmark)

    Lock, Charles

    2015-01-01

    Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology.......Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology....

  8. Effects of Basalt Fibres on Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    El-Gelani A. M.

    2018-01-01

    Full Text Available This paper presents the results of an experimental program carried out to investigate the effects of Basalt Fibre Reinforced Polymers (BFRP on some fundamental mechanical properties of concrete. Basalt fibres are formed by heating crushed basalt rocks and funnelling the molten basalt through a spinneret to form basalt filaments. This type of fibres have not been widely used till recently. Two commercially available chopped basalt fibres products with different aspect ratios were investigated, which are dry basalt (GeoTech Fibre and basalt pre-soaked in an epoxy resin (GeoTech Matrix .The experimental work included compression tests on 96 cylinders made of multiple batches of concrete with varying amounts of basalt fibre additives of the two mentioned types, along with control batches containing no fibres. Furthermore, flexural tests on 24 prisms were carries out to measure the modulus of rupture, in addition to 30 prisms for average residual strength test. Results of the research indicated that use of basalt fibres has insignificant effects on compressive strength of plain concrete, where the increase in strength did not exceed about 5%. On the other hand, results suggest that the use of basalt fibres may increase the compressive strength of concrete containing fly as up top 40%. The rupture strength was increased also by 8% to 28% depending on mix and fibre types and contents. Finally, there was no clear correlation between the average residual strength and ratios of basalt fibres mixed with the different concrete batches.

  9. Geochemical characteristics of the Jos-Plateau Basalts, North ...

    African Journals Online (AJOL)

    The Jos Plateau basalts, present Zr/Nb ratios (2.4-3.0) comparable to those of the alkali basalts of the lower Benue valley, and of the Cameroon volcanic line, suggesting that they were possibly derived from the same mantle source. Keywords: Jos Plateau, alkali basalt, mantle, partial melting, incompatible elements.

  10. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  11. High-Ti type N-MORB parentage of basalts from the south Andaman ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    basalts as sub-alkaline basalts and alkaline basalts. A few samples show basaltic andesite, trachy- basalt, or basanitic chemical composition. High-field strength element (HFSE) geochemistry sug- gests that studied basalt samples are probably derived from similar parental magmas. Al2O3/TiO2 and CaO/TiO2 ratios classify ...

  12. Sulfur partitioning applied to LIP magmatism - A new approach for quantifying sulfur concentration in basaltic melts

    Science.gov (United States)

    Marzoli, A.; Callegaro, S.; Baker, D. R.; De Min, A.; Cavazzini, G.; Martin, W.; Renne, P. R.; Svensen, H.

    2017-12-01

    Magmatism from Large Igneous Provinces (LIPs) has often been demonstrated synchronous with mass extinctions. Prominent examples in the Phanerozoic are the end-Permian, end-Triassic and end-Cretaceous extinctions, associated with, respectively, the Siberian Traps, the CAMP and the Deccan Traps. Despite the growing body of evidence for causal and temporal links between these events, it is not yet entirely clear how a LIP can severly affect the global environment. Degassing of volatile species such as S, C and halogen compounds directly from LIP magmas, and from contact metamorphism of volatile-rich sediments heated by the intrusions appears as the most realistic mechanism. Modeling the atmospheric response to LIP gas loads requires quantitative constraints on the degassed volatiles and emission rates, but these are challenging to obtain for magmatic systems from the geologic past. We therefore propose a new method to calculate the sulfur load of basaltic melts, by measuring sulfur content in natural minerals (clinopyroxene and plagioclase) and combining it with an experimentally determined partition coefficients (KD). We measured partitioning of sulfur between crystals and melt by ion microprobe (Nordsim, Stockholm) on experimentally produced crystals and glasses. Piston cylinder experiments were performed with conditions typical of basaltic, andesitic and dacitic melts (800 or 1000 MPa; 1000°-1350°C), to constrain KD variations as a function of melt composition, oxidation state and water content. We obtained a clinopyroxene/melt sulfur KD of 0.001 for basaltic melts, which can be applied to natural continental flood basalts. Preliminary results from thoroughly-dated lava piles from the Deccan Traps and from the Siberian Traps sills confirm that most of the basalts were at or close to sulfide saturation (ca. 2000 ppm for low fO2 melts). These results can be compared with the scenario modeled by Schmidt et al. (2016) for Deccan Traps magmatism, for which sulfur from

  13. The boron and lithium isotopic composition of mid-ocean ridge basalts and the mantle

    OpenAIRE

    Marschall, H.R.; Wanless, V.D.; Shimizu, N.; Pogge von Strandmann, Philip A.E.; Elliott, T.; Monteleone, B.D.

    2017-01-01

    A global selection of 56 mid-ocean ridge basalt (MORB) glasses were analysed for Li and B abundances and isotopic compositions. Analytical accuracy and precision of analyses constitute an improvement over previously published MORB data and allow a more detailed discussion of the Li and B systematics of the crust-mantle system. Refined estimates for primitive mantle abundances ([Li]=1.39±0.10[Li]=1.39±0.10 μg/g and [B]=0.19±0.02[B]=0.19±0.02 μg/g) and depleted mantle abundances ([Li]=1.20±0.10...

  14. Basaltic substrate composition affects microbial community development and acts as a source of nutrients in the deep biosphere

    Science.gov (United States)

    Bailey, B.; Sudek, L.; Templeton, A.; Staudigel, H.; Tebo, B.; Moyer, C.; Davis, R.

    2006-12-01

    Studies of the oceanic crust over the past decade have revealed that in spite of the oligotrophic nature of this environment, a diverse biosphere is present in the upper 1 km of basaltic crust. The key energy source in this setting may be the high content of transistion metals (Fe, Mn) found in the basaltic glass, but in order to discover the role of Fe and Mn in the deep biosphere, we must first determine which microbes are present and how they attain the necessary metabolites for proliferation. Our work contributes to both questions through the use of molecular microbiology techniques and the exposure of specifically designed substrates on the ocean floor. Loihi Seamount off the southeast coast of the Big Island of Hawai'i provides a unique laboratory for the study of distribution and population of microbial communities associated with iron rich environments on the ocean floor. Iron oxide flocculent material (floc) dominates the direct and diffuse hydrothermal venting areas on Loihi which makes it a prime target for understanding the role of iron in biological systems in the deep biosphere. We collected iron oxide floc and basaltic glass from pillow basalts around several hydrothermal vents on the crater rim, within the pit crater Pele's Pit, and from deep off of the southern rift zone of Loihi using the HURL PISCES IV/V submersibles. We also deployed basaltic glass sand amended with various nutrients (phosphate, oxidized and reduced iron, manganese) and recovered them in subsequent years to determine how substrate composition affects community structure. We extracted DNA from both rock and iron flocs and used t-RFLP to obtain a genetic fingerprint of the microbial communities associated with each substrate. From olivine and tholeiitic basalt enrichments, it appears that substrate composition strongly influences microbial colonization and subsequent community development even when deployed in the same conditions. Culturing efforts have yielded several iron

  15. Experimental hydration studies of natural and synthetic glasses

    International Nuclear Information System (INIS)

    Bates, J.K.; Abrajano, T.A. Jr.; Ebert, W.L.; Mazer, J.J.; Gerding, T.J.

    1988-01-01

    The results of a series of hydration experiments on natural glasses (Hawaiian basalt, obsidian) and the nuclear waste glass WV-44 done to examine laboratory methods of accelerating reaction processes are summarized. The glasses were reacted in hydrothermal solution and in saturated vapor water. It was found that different reaction rates and processes were found using the differing conditions, and that laboratory efforts to accelerate and duplicate natural processes must amount for the physical processes that occur naturally. 18 refs., 5 figs., 1 tab

  16. Influence of microorganisms on the alteration of glasses

    International Nuclear Information System (INIS)

    Besnainou, B.; Libert, M.F.

    1997-01-01

    Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

  17. Biogenic Mn-Oxides in Subseafloor Basalts.

    Science.gov (United States)

    Ivarsson, Magnus; Broman, Curt; Gustafsson, Håkan; Holm, Nils G

    2015-01-01

    The deep biosphere of the subseafloor basalts is recognized as a major scientific frontier in disciplines like biology, geology, and oceanography. Recently, the presence of fungi in these environments has involved a change of view regarding diversity and ecology. Here, we describe fossilized fungal communities in vugs in subseafloor basalts from a depth of 936.65 metres below seafloor at the Detroit Seamount, Pacific Ocean. These fungal communities are closely associated with botryoidal Mn oxides composed of todorokite. Analyses of the Mn oxides by Electron Paramagnetic Resonance spectroscopy (EPR) indicate a biogenic signature. We suggest, based on mineralogical, morphological and EPR data, a biological origin of the botryoidal Mn oxides. Our results show that fungi are involved in Mn cycling at great depths in the seafloor and we introduce EPR as a means to easily identify biogenic Mn oxides in these environments.

  18. Hydrologic modeling of the Columbia Plateau basalts

    International Nuclear Information System (INIS)

    Dove, F.H.; Cole, C.R.; Bond, F.W.; Zimmerman, D.A.

    1982-09-01

    The Office of Nuclear Waste Isolation (ONWI) directed the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program to conduct a technology demonstration of current performance assessment techniques for the Department of Energy (DOE) as applied to a nuclear waste repository in the Columbia Plateau Basalts. Hypothetical repository coordinates were selected for an actual geographical setting on the Hanford Reservation in the state of Washington. Published hydrologic and geologic data used in the analyses were gathered in 1979 or earlier. The hydrologic simulation was divided into three major parts: (1) aquifer recharge calculations, (2) a regional hydrologic model, and (3) a local hydrologic model of the Pasco Basin. The presentation discusses the regional model. An estimate of the amount of water transmitted through the groundwater system was required to bound the transmissivity values and to estimate the transmissivity distributions for the deeper basalts. The multiple layer two-dimensional Variable Thickness Transient (VTT) code was selected as appropriate for the amount of data available and for the conditions existing in the regional systems. This model uses a finite difference formulation to represent the partial differential flow equation. The regional study area as defined for the VTT model was divided into 55 by 55 square pattern with each grid 5 kilometers on a side. The regional system was modeled as a held potential surface layer and two underlying basalt layers. The regional model established the boundary conditions for the hydrologic model the Pasco Basin

  19. The rheological evolution of alkaline Vesuvius magmas and comparison with alkaline series from the Phlegrean Fields, Etna, Stromboli and Teide

    Science.gov (United States)

    Giordano, D.; Ardia, P.; Romano, C.; Dingwell, D. B.; Di Muro, A.; Schmidt, M. W.; Mangiacapra, A.; Hess, K.-U.

    2009-11-01

    relevance in the context of hazard assessment related to the different possible eruptive scenarios at Vesuvius through numerical simulation tools. The effect of composition on the liquid viscosities is compared to other high-Na (e.g., samples from Teide and Etna) and high-K (e.g., samples from Stromboli and Phlegrean Fields) alkaline magmas.

  20. The 30 December 2002 landslide-induced tsunamis in Stromboli: sequence of the events reconstructed from the eyewitness accounts

    Science.gov (United States)

    Tinti, S.; Manucci, A.; Pagnoni, G.; Armigliato, A.; Zaniboni, F.

    2005-10-01

    On 30 December 2002 the coast of the volcanic island of Stromboli, in the Tyrrhenian sea, Italy, was attacked by two tsunamis generated by landslides that took place on the north-west flank of the volcano. The landslides and the tsunamis represented the most impressive and threatening episodes of a strong effusive eruption, started on 28 December from a new vent which opened close to the north-east crater of the volcano. In spite of the intensified monitoring carried out in response to the eruption, the landslides and the ensuing tsunamis were not foreseen, and the available instrumental data are insufficient to allow a precise reconstruction of the sequence of the events. The seismic network recorded two main landslides along the steep slope of Sciara del Fuoco, with onset around 13:15 and 13:23 local time (GMT+1). The tsunamis were the direct consequence of the mass movements. Three main post-event surveys helped make assessment on the wave impact on the coast. In this paper the attention is focussed on the accounts of the eye-witnesses, that help us clarify and understand what happened. People in the source area (Sciara del Fuoco) reported a small-volume subaerial slide taking place first, then a sharp cut forming in the sea water down to the sea floor (about 10-20 m deep) and propagating almost parallel to the coastline, be concomitantly associated with a sea retreat and a subsequent sea advance. It is suggested here that the cut was the effect of a large submarine landslide that detached from very close to the coast and produced the 13:15 signal in the recorded seismograms. The second, mostly subaerial, slump was observed to slide down 7-8 min later and to excite a train of waves some distance offshore. Not all the witnesses realised that two distinct tsunamis occurred. The tsunami period was probably in the order of 100 s, but shorter period crests were seen to travel on the top of the long-period waves by several persons. The duration of each tsunami was

  1. The 30 December 2002 landslide-induced tsunamis in Stromboli: sequence of the events reconstructed from the eyewitness accounts

    Directory of Open Access Journals (Sweden)

    S. Tinti

    2005-01-01

    Full Text Available On 30 December 2002 the coast of the volcanic island of Stromboli, in the Tyrrhenian sea, Italy, was attacked by two tsunamis generated by landslides that took place on the north-west flank of the volcano. The landslides and the tsunamis represented the most impressive and threatening episodes of a strong effusive eruption, started on 28 December from a new vent which opened close to the north-east crater of the volcano. In spite of the intensified monitoring carried out in response to the eruption, the landslides and the ensuing tsunamis were not foreseen, and the available instrumental data are insufficient to allow a precise reconstruction of the sequence of the events. The seismic network recorded two main landslides along the steep slope of Sciara del Fuoco, with onset around 13:15 and 13:23 local time (GMT+1. The tsunamis were the direct consequence of the mass movements. Three main post-event surveys helped make assessment on the wave impact on the coast. In this paper the attention is focussed on the accounts of the eye-witnesses, that help us clarify and understand what happened. People in the source area (Sciara del Fuoco reported a small-volume subaerial slide taking place first, then a sharp cut forming in the sea water down to the sea floor (about 10–20 m deep and propagating almost parallel to the coastline, be concomitantly associated with a sea retreat and a subsequent sea advance. It is suggested here that the cut was the effect of a large submarine landslide that detached from very close to the coast and produced the 13:15 signal in the recorded seismograms. The second, mostly subaerial, slump was observed to slide down 7–8 min later and to excite a train of waves some distance offshore. Not all the witnesses realised that two distinct tsunamis occurred. The tsunami period was probably in the order of 100 s, but shorter period crests were seen to travel on the top of the long-period waves by several persons. The duration of

  2. Simulated high-level waste-basalt interaction experiments. First interim progress report

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, G.J.; Scheetz, B.E.; Komarneni, S.; Barnes, M.; Smith, C.A.; Lewis, J.F.; Smith, D.K.

    1978-03-24

    Reconnaissance experiments have shown that waste/basalt interactions are of real importance in understanding all aspects of total containment of radionuclides in a basalt repository. It has been shown that the reprocessed waste forms, calcine and glass, are relatively more reactive than the more crystalline waste forms, spent unreprocessed fuel (SURF) and supercalcine. These experiments have established the direction of future research. The remainder of the program will be concerned with longer-duration and more-detailed experiments whose emphasis will be on understanding the mechanisms of reaction. Long-duration and in-depth experiments are being initiated to establish kinetic relationships and get a better feel as to whether or not we are approaching equilibrium in our shorter-duration reconnaissance experiments. In some cases, especially at higher temperatures, it appears that we are approaching a steady-state wherein products are no longer changing. This, however, might be a metastable state. Experiments with cesium compounds thought to be present in SURF (Cs/sub 2/MoO/sub 4/), a simple cesium source (CsOH), labradorite, and ground water have shown that pollucite forms and, as a result, fixes 86 to 99% of the cesium (depending upon the amount of basalt present.

  3. Constructing the volcanic architecture of Kalkarindji, an ancient flood basalt province, using a multidisciplinary approach

    Science.gov (United States)

    Marshall, P.; Widdowson, M.; Kelley, S. P.; Mac Niocaill, C.; Murphy, D. T.

    2014-12-01

    The Kalkarindji Continental Flood Basalt Province (CFBP) is the oldest igneous province in the Phanerozoic. Erupted in the mid-Cambrian (505-510 Ma) [1], it is estimated volumes of lava up to 1.5 x 105 km3could have been erupted, making this similar in size to the better known Columbia River Basalts, USA. Relatively little is known about the province, due in part to its remote location, though large swathes remain well preserved (c. 50,000 km2). This study, based on rigorous field investigations, utilises 4 different analytical techniques to construct a volcanic architecture for the Kalkarindji basalts, drawing together these complimentary datasets to generate a series of detailed stratigraphies from around the province. Mineralogy and petrography form the basis while geochemical data aides in defining lava flow stratigraphies and distinguishing individual flow packages in disparate locations around the province. 40Ar/39Ar dating of key stratigraphic marker horizons support stratigraphical correlation across the province whilst the use of palaeomagnetism and magnetostratigraphy has allowed for correlation on a broader scale. Indications from this study point towards an unusual eruption among CFBPs in the Phanerozoic; a lack of tumescence, immediate subsidence of the lava pile following cessation of eruption; and, in the main sub-province, we map a simple volcanic structure thinning to the east from a single source. 1. L. M. Glass, D. Phillips, (2006). Geology. 34, 461-464.

  4. Implementation of electrochemical, optical and denuder-based sensors and sampling techniques on UAV for volcanic gas measurements: examples from Masaya, Turrialba and Stromboli volcanoes

    Directory of Open Access Journals (Sweden)

    J. Rüdiger

    2018-04-01

    Full Text Available Volcanoes are a natural source of several reactive gases (e.g., sulfur and halogen containing species and nonreactive gases (e.g., carbon dioxide to the atmosphere. The relative abundance of carbon and sulfur in volcanic gas as well as the total sulfur dioxide emission rate from a volcanic vent are established parameters in current volcano-monitoring strategies, and they oftentimes allow insights into subsurface processes. However, chemical reactions involving halogens are thought to have local to regional impact on the atmospheric chemistry around passively degassing volcanoes. In this study we demonstrate the successful deployment of a multirotor UAV (quadcopter system with custom-made lightweight payloads for the compositional analysis and gas flux estimation of volcanic plumes. The various applications and their potential are presented and discussed in example studies at three volcanoes encompassing flight heights of 450 to 3300 m and various states of volcanic activity. Field applications were performed at Stromboli volcano (Italy, Turrialba volcano (Costa Rica and Masaya volcano (Nicaragua. Two in situ gas-measuring systems adapted for autonomous airborne measurements, based on electrochemical and optical detection principles, as well as an airborne sampling unit, are introduced. We show volcanic gas composition results including abundances of CO2, SO2 and halogen species. The new instrumental setups were compared with established instruments during ground-based measurements at Masaya volcano, which resulted in CO2 ∕ SO2 ratios of 3.6 ± 0.4. For total SO2 flux estimations a small differential optical absorption spectroscopy (DOAS system measured SO2 column amounts on transversal flights below the plume at Turrialba volcano, giving 1776 ± 1108 T d−1 and 1616 ± 1007 T d−1 of SO2 during two traverses. At Stromboli volcano, elevated CO2 ∕ SO2 ratios were observed at spatial and temporal proximity

  5. SO2 flux monitoring at Stromboli with the new permanent INGV SO2 camera system: A comparison with the FLAME network and seismological data

    Science.gov (United States)

    Burton, M. R.; Salerno, G. G.; D'Auria, L.; Caltabiano, T.; Murè, F.; Maugeri, R.

    2015-07-01

    We installed a permanent SO2 camera system on Stromboli, Italy, in May 2013, in order to improve our capacity to monitor the SO2 emissions from this volcano. The camera collects images of SO2 concentrations with a period of 10 s, allowing quantification of short-term processes, such as the gas released during the frequent explosions which are synonymous with Stromboli. It also allows quantification of the quiescent gas flux, and therefore comparison with the FLAME network of scanning ultraviolet spectrometers previously installed on the island. Analysis of results from the SO2 camera demonstrated a good agreement with the FLAME network when the plume was blown fully into the field of view of the camera. Permanent volcano monitoring with SO2 cameras is still very much in its infancy, and therefore this finding is a significant step in the use of such cameras for monitoring, whilst also highlighting the requirement of a favourable wind direction and strength. We found that the explosion gas emissions are correlated with seismic events which have a very long period component. There is a variable time lag between event onset time and the increase in gas flux observed by the camera as the explosion gas advects into the field of view of the camera. This variable lag is related to the plume direction, as shown by comparison with the plume location detected with the FLAME network. The correlation between explosion gas emissions and seismic signal amplitude show is consistent with a gas slug-driven mechanism for seismic event production. Comparison of the SO2 camera measurements of the quiescent gas flux shows a fair quantitative agreement with the SO2 flux measured with the FLAME network. Overall, the SO2 camera complements the FLAME network well, as it allows frequent quantification of the explosion gas flux produced by Stromboli, whose signal is in general too brief to be measured with the FLAME network. Further work is required, however, to fully automate the

  6. Integration of seismic and Ground-Based InSAR displacement data: a tool to understand conduit dynamic at Stromboli Volcano

    Science.gov (United States)

    Cauchie, Léna; Di Traglia, Federico; Casagli, Nicola; Saccorotti, Gilberto

    2014-05-01

    Stromboli is an open-conduit volcano, which does not experience pressurization of the magma storage and/or plumbing system able to produce ground deformations at the scale of the volcanic edifice. For any such system, localized inflations/deflations are rather expected in response to conduit processes, such as magma convection and uprising. Indeed, detectable ground deformations at Stromboli volcano have only been observed in association with dyke intrusion at shallow depth, prior to the opening of new eruptive fractures. In this work, we present the integration of seismic and Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) system displacement data recorded at Stromboli volcano aimed at a better understanding of the geophysical signals associated with magma dynamics in an open volcanic system. A cross-analysis between the tiny GBInSAR deformations and ground displacements in the seismological frequency band (0.02-10 Hz) is performed for the period spanning 6 June 2011 - 27 August 2011, which was characterized by an activity of higher intensity than usually observed. The period under study includes seven major explosions and two lava overflows from the NE vents (1-2 August and 18 August 2011). The time series of GBInSAR displacement at the summit vents area is positively correlated with both volcanic tremor amplitude and the number and amplitude of very-long-period (VLP) signals that are associated with the Strombolian explosions. While the correlation between GBInSAR and tremor time series takes its maximum at zero lag time, the variation in frequency and energy of VLP events anticipate by a few days the inflation of the vents area and the increase of volcanic tremor. We thus suggest a general mechanism to explain the observed trend in the geophysical signals. In our model, the arrival of fresh, gas-rich magma from below enhance slug formations, promoting convection and gas transfer throughout the conduit system. At the shallowest portion of the

  7. Spin glasses

    International Nuclear Information System (INIS)

    Fischer, K.H.; Hertz, J.A.

    1993-01-01

    Spin glasses, simply defined by the authors as a collection of spins (i.e., magnetic moments) whose low-temperature state is a frozen disordered one, represent one of the fascinating new fields of study in condensed matter physics, and this book is the first to offer a comprehensive account of the subject. Included are discussions of the most important developments in theory, experimental work, and computer modeling of spin glasses, all of which have taken place essentially within the last two decades. The first part of the book gives a general introduction to the basic concepts and a discussion of mean field theory, while the second half concentrates on experimental results, scaling theory, and computer simulation of the structure of spin glasses

  8. Volatile Release and Eruption Dynamics of a Basaltic Plinian Eruption From Masaya Caldera, Nicaragua

    Science.gov (United States)

    Wehrmann, H.; Freundt, A.; Kutterolf, S.; Schmincke, H.; Strauch, W.

    2003-12-01

    Our project is part of SFB 574 "Volatiles and Fluids in subduction zones", and focusses on degassing dynamics of highly-explosive arc volcanoes. Masaya Caldera in west-central Nicaragua is part of the Central American volcanic arc at the convergent boundary of the Cocos and Carribean plates. A basaltic plinian eruption of VEI 6 occurred at Masaya Caldera in the Late-Pleistocene, depositing a widespread fan of scoria lapilli, named Fontana Tephra. We have constrained parameters of the Fontana eruption by extensive isopach and isopleth mapping. Total erupted tephra volume is >0.83 km3 (about 1012 kg DRE). The eruption columns reached 30 to 35 km height at an average discharge rate of 1.3*108 kg/s. This violent eruption was not continuous but proceeded in distinct pulses evident by the well-bedded deposit. An initial sequence of numerous highly explosive but short pulses formed a well-bedded layer of very highly vesicular, hawaiian-type lapilli, possibly representing a gas-enriched top zone of the magma reservoir. The following series of longer-duration plinian events, interupted by weak phases of ash emission, formed beds of highly vesicular scoria lapilli. The eruption ceased with abundant short-lived pulses of lower-energy subplinian activity. We estimate volatile emissions during the eruption from the differences in volatile concentration between matrix glass and glass inclusions in minerals, considered to represent degassed and undegassed melt, respectively. Concentrations of fluorine of about 7000 ppm are about equal in matrix glass and glass inclusions, indicating little degassing of fluorine during eruption. Chlorine contents amount to 1200 ppm in the inclusions, and to about 1000 ppm in matrix glass. The concentration difference, multiplied by erupted magma mass, suggests a total chlorine emission of 16 Mt. Apparently only little chlorine exsolved in the initial eruption phase, but degassing strongly increased during the plinian phase. Sulphur concentrations

  9. Submarine Flood Basalt Eruptions and Flows of Ontong Java Plateau, Nauru Basin and East Mariana Basin

    Science.gov (United States)

    Michael, P. J.; Trowbridge, S. R.; Zhang, J.; Johnson, A. L.

    2016-12-01

    The preservation of fresh basalt glasses from the submarine Cretaceous Ontong Java Plateau (OJP), Earth's largest LIP, has allowed correlation of precise lava compositions over 100s of km, as well as determination of eruption depths using dissolved H2O and CO2 contents. Low dissolved H2O in glasses shows that H2O in the mantle source is low [1,2], suggesting mantle temperatures are high. Very high dissolved Cl indicates that magmas interacted extensively with brines. The near total absence of vesicles in OJP glasses contrasts sharply with MORB, and suggests that OJP lavas were saturated or undersaturated with CO2 when they were emplaced, in contrast to MORB that are often oversaturated. The lavas likely remained liquid for a longer period of time so that they degassed to equilibrium levels of dissolved CO2 andlost all bubbles. Very precise major and trace element analyses of glasses, uncomplicated by crystals or alteration, show how lavas within and between widely-spaced drill holes could be related. For example, glasses from Sites 1185B and 1186A, which are about 200 km apart, are compositionally identical within precise limits and must have erupted from the same well-mixed magma chamber. They erupted at about the same depth, but 1186A has a corrected basement depth that is >700m deeper. With a slope of 0.3°, this suggests a flow distance >130km. The eruption depths for glasses from East Mariana and Nauru Basins are similar to those of 1185B and 1186A on OJP, even though their reconstructed basement depths are about 2000 m deeper. It suggests that the plateau lavas flowed into the basins. Similarly, eruption depths in Hole 807C are 3040m for Kwaimbaita lavas but are 1110m [1,2] for Singgalo lavas that directly overlie them. It is unlikely that plateau uplift and subsidence accounts for the observed eruption depths. All of these observations are best explained by very large-volume eruptions whose lavas traveled for long distances, up to 100s of km, into deeper

  10. Chlorine isotope composition of volcanic rocks and gases at Stromboli volcano (Aeolian Islands, Italy): Inferences on magmatic degassing prior to 2014 eruption

    Science.gov (United States)

    Liotta, Marcello; Rizzo, Andrea L.; Barnes, Jaime D.; D'Auria, Luca; Martelli, Mauro; Bobrowski, Nicole; Wittmer, Julian

    2017-04-01

    Among the magmatic volatiles, chlorine (Cl) is degassed at shallow depths offering the opportunity to investigate the behavior of magmatic degassing close to the surface, and the possible occurrence of chemical and isotopic fractionation related to gas/melt partitioning. However, it is still unclear if the isotopic composition of Cl (δ37Cl) can be used as a proxy of magmatic degassing. In this work, we investigate the concentrations of chlorine and sulfur, and the Cl isotope composition of rocks and plume gases collected at Stromboli volcano, Aeolian Islands, Italy. This volcano was chosen because it is characterized by persistent eruptive activity (i.e., Strombolian explosions) and by the presence of magma at very shallow levels in the conduits. Rocks belonging to the different magmatic series erupted throughout the formation of the volcano have δ37Cl values ranging between - 1.0 and + 0.7‰. The isotopic composition seems independent of the Cl concentration of the rocks, but shows a negative correlation with SiO2 content. Plume gases have a greater isotopic compositional variability than the rocks (- 2.2‰ ≤ δ37Cl ≤ + 1.5‰) and the composition seems related to the level of volcanic activity at Stromboli. Gases collected in 2011-2013 during days of ordinary eruptive activity are characterized by δ37Cl values ranging from + 0.3 to + 1.5‰ and S/Cl molar ratios between 1.4 and 2.2, similar to previous S/Cl measurements performed at Stromboli with other techniques. Plume gases collected in July 2014, in days of high-level eruptive activity preceding the onset of the 2014 effusive eruption, have negative δ37Cl values (- 2.2‰ ≤ δ37Cl ≤ - 0.1‰) and S/Cl between 0.9 and 1.2, which are among the lowest S/Cl values measured at this volcano. The amplitude of the volcanic tremor and the variation in the inclination of very long period (VLP) seismic signal polarization clearly indicate that in July 2014 the intensity and frequency of Strombolian

  11. From hot rocks to glowing avalanches: Numerical modelling of gravity-induced pyroclastic density currents and hazard maps at the Stromboli volcano (Italy)

    Science.gov (United States)

    Salvatici, Teresa; Di Roberto, Alessio; Di Traglia, Federico; Bisson, Marina; Morelli, Stefano; Fidolini, Francesco; Bertagnini, Antonella; Pompilio, Massimo; Hungr, Oldrich; Casagli, Nicola

    2016-11-01

    Gravity-induced pyroclastic density currents (PDCs) can be produced by the collapse of volcanic crater rims or due to the gravitational instability of materials deposited in proximal areas during explosive activity. These types of PDCs, which are also known as ;glowing avalanches;, have been directly observed, and their deposits have been widely identified on the flanks of several volcanoes that are fed by mafic to intermediate magmas. In this research, the suitability of landslide numerical models for simulating gravity-induced PDCs to provide hazard assessments was tested. This work also presents the results of a back-analysis of three events that occurred in 1906, 1930 and 1944 at the Stromboli volcano by applying a depth-averaged 3D numerical code named DAN-3D. The model assumes a frictional internal rheology and a variable basal rheology (i.e., frictional, Voellmy and plastic). The numerical modelling was able to reproduce the gravity-induced PDCs' extension and deposit thicknesses to an order of magnitude of that reported in the literature. The best results when compared with field data were obtained using a Voellmy model with a frictional coefficient of f = 0.19 and a turbulence parameter ξ = 1000 m s- 1. The results highlight the suitability of this numerical code, which is generally used for landslides, to reproduce the destructive potential of these events in volcanic environments and to obtain information on hazards connected with explosive-related, mass-wasting phenomena in Stromboli Island and at volcanic systems characterized by similar phenomena.

  12. Metallic glasses

    NARCIS (Netherlands)

    Schaafsma, Arjen Sybren

    1981-01-01

    It is shown in section 7.1. that the influence of topological disorder on the range of magnetic interactions in ferromagnetic transition metal-metalloid (TM-M) glasses, is much less than often assumed. This is demonstrated via a study of the temperature dependence of the average iron hyperfine field

  13. Degassing of reduced carbon from planetary basalts.

    Science.gov (United States)

    Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E

    2013-05-14

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential.

  14. Spectroscopic analysis (FTIR, Raman) of water in mafic and intermediate glasses and glass inclusions

    International Nuclear Information System (INIS)

    Mercier, Maxime; Di Muro, Andrea; Metrich, Nicole; Belhadj, Olfa; Giordano, Daniele; Mandeville, Charles W.

    2010-01-01

    Micro-Raman spectroscopy, even though a very promising technique, is not still routinely applied to analyse H 2 O in silicate glasses. The accuracy of Raman water determinations critically depends on the capability to predict and take into account both the matrix effects (bulk glass composition) and the analytical conditions on band intensities. On the other hand, micro-Fourier transform infrared spectroscopy is commonly used to measure the hydrous absorbing species (e.g., hydroxyl OH and molecular H 2 O) in natural glasses, but requires critical assumptions for the study of crystal-hosted glasses. Here, we quantify for the first time the matrix effect of Raman external calibration procedures for the quantification of the total H 2 O content (H 2 O(T) = OH - + H 2 O m ) in natural silicate glasses. The procedures are based on the calibration of either the absolute (external calibration) or scaled (parameterization) intensity of the 3550 cm -1 band. A total of 67 mafic (basanite, basalt) and intermediate (andesite) glasses hosted in olivines, having between 0.2 and 4.8 wt% of H 2 O, was analysed. Our new dataset demonstrates, for given water content, the height (intensity) of Raman H 2 OT band depends on glass density, reflectance and water environment. Hence this matrix effect must be considered in the quantification of H 2 O by Raman spectroscopy irrespective of the procedure, whereas the parameterization mainly helps to predict and verify the self-consistency of the Raman results. In addition, to validate the capability of the micro-Raman to accurately determine the H 2 O content of multicomponent aluminosilicate glasses, a subset of 23 glasses was analysed by both micro-Raman and micro-FTIR spectroscopy using the band at 3550 cm -1 . We provide new FTIR absorptivity coefficients ε 3550 ) for basalt (62.80 ± 0.8 L mol -1 cm -1 ) and basanite (43.96 ± 0.6 L mol -1 cm -1 ). These values, together with an exhaustive review of literature data, confirm the non

  15. Constructibility issues associated with a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Turner, D.A.

    1981-01-01

    This report contains the text and slide reproductions of a speech on nuclear waste disposal in basalt. The presentation addresses the layout of repository access shafts and subsurface facilities resulting from the conceptual design of a nuclear repository in basalt. The constructibility issues that must be resolved prior to construction are described

  16. Hydrogeology of the basalts in the Uruguayan NW

    International Nuclear Information System (INIS)

    Hausman, A.; Fernandez, A.

    1967-01-01

    This work is about the hydrogeological aspects in the NW Uruguayan basaltic area. The results of this research are the main geological, morphological and hydrogeological aspects of the area as well as the characteristics and the color of the basalt and sandstones

  17. A note on incipient spilitisation of central Indian basin basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Iyer, S.D.

    of chlorite, epidote and opaques. The oxide variation plots indicate a mid-ocean ridge basalt trend for the samples, which have been spilitised to varying degrees. It is suggested that the basalts formed as a result of a fissure type of eruption along...

  18. Use of basaltic waste as red ceramic raw material

    Directory of Open Access Journals (Sweden)

    T. M. Mendes

    Full Text Available Abstract Nowadays, environmental codes restrict the emission of particulate matters, which result in these residues being collected by plant filters. This basaltic waste came from construction aggregate plants located in the Metropolitan Region of Londrina (State of Paraná, Brazil. Initially, the basaltic waste was submitted to sieving (< 75 μm and the powder obtained was characterized in terms of density and particle size distribution. The plasticity of ceramic mass containing 0%, 10%, 20%, 30%, 40% and 50% of basaltic waste was measured by Atterberg method. The chemical composition of ceramic formulations containing 0% and 20% of basaltic waste was determined by X-ray fluorescence. The prismatic samples were molded by extrusion and fired at 850 °C. The specimens were also tested to determine density, water absorption, drying and firing shrinkages, flexural strength, and Young's modulus. Microstructure evaluation was conducted by scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry. Basaltic powder has similar physical and chemical characteristics when compared to other raw materials, and contributes to ceramic processing by reducing drying and firing shrinkage. Mechanical performance of mixtures containing basaltic powder is equivalent to mixtures without waste. Microstructural aspects such as pore size distribution were modified by basaltic powder; albite phase related to basaltic powder was identified by X-ray diffraction.

  19. Mineral chemistry of Pangidi basalt flows from Andhra Pradesh

    Indian Academy of Sciences (India)

    Pangidi basalts follow the QFM buffer curve which indicates the more evolved tholeiitic composition. This suggests the parent tholeiitic magma suffered limited fractionation at high temperature under increasing oxygen fugacity in lower basalt flow and more fractionation at medium to lower temperatures under decreasing ...

  20. Basalt Weathering and the Volatile Budget of Early Mars

    Science.gov (United States)

    Baker, L. L.

    2017-10-01

    Basalt weathering on Earth consumes CO2 and water and may have affected terrestrial climate. I apply a mass balance derived from terrestrial data to examine the effect surficial basalt weathering may have had on the CO2 budget of early Mars.

  1. Influence of basalt/groundwater interactions on radionuclide migration

    International Nuclear Information System (INIS)

    Vandegrift, G.F.

    1984-01-01

    The work presented here is a partial summary of the experimental results obtained in the Laboratory Analog Program. Two aspects of this effort are (1) the interaction between simulated basaltic groundwater and basalt fissures that were either freshly cleaved or laboratory altered by hydrothermal treatment with the simulated groundwater and (2) the effect of this interaction on radionuclide migration through these basalt fissures. The following conclusions of this study bear heavily on the predicted safety of a basalt repository: Sorption properties of freshly fissured basalt and naturally aged basalt are quite different for different chemical species. Analog experiments predict that aged basalt would be an effective retarder of cesium, but would be much less so for actinide elements. Distribution ratios measured from batch experiments with finely ground rock samples (presenting unaltered rock surfaces) are not a reliable means of predicting radionuclide migration in geological repositories. As the near-repository area is resaturated by groundwater, its ability to retard actinide migration will be degraded with time. Disturbing the natural flow of groundwater through the repository area by constructing and backfilling the repository will modify the composition of groundwater. This modified groundwater is likely to interact with and to modify naturally aged basalt surfaces downstream from the repository

  2. Rapid solubility and mineral storage of CO2 in basalt

    DEFF Research Database (Denmark)

    Gislason, Sigurdur R.; Broecker, W.S.; Gunnlaugsson, E.

    2014-01-01

    rich in divalent metal cations such as basalts and ultra-mafic rocks. We have demonstrated the dissolution of CO2 into water during its injection into basalt leading to its geologic solubility storage in less than five minutes and potential geologic mineral storage within few years after injection [1...

  3. Hydrothermal interactions of cesium and strontium phases from spent unreprocessed fuel with basalt phases and basalts

    Energy Technology Data Exchange (ETDEWEB)

    Komarneni, S.; Scheetz, B.E.; McCarthy, G.J.; Coons, W.E.

    1980-03-01

    This investigation is a segment of an extensive research program aimed at investigating the feasibility of long-term, subsurface storage of commercial nuclear waste. Specifically, it is anticipated that the waste will be housed in a repository mined from the basalt formations which lie beneath the Hanford Site. The elements monitored during the present experiments were Cs and Sr. These two elements represent significant biohazards if released from a repository and are the major heat producing radionuclides present in commercial radioactive waste. Several Cs phases and/or solutions were reacted with either isolated basalt phases or bulk-rock basalt, and the resulting solids and solutions were analyzed. The hydrothermal reactivity of SrZrO/sub 3/, which is believed to be a probable host for Sr in SFE was investigated. While so far no evidence exists which indicates that Sr is present in a water soluble phase in spent fuel elements (SFE), detailed investigation of a potential hazard is warranted. This investigation has determined that some Cs compounds likely to be stable components of spent fuel (i.e., CsOH, Cs/sub 2/MoO/sub 4/, Cs/sub 2/U/sub 2/O/sub 7/) have significant hydrothermal solubilities. These solubilities are greatly decreased in the presence of basalt and/or basalt minerals. The decrease in the amount of Cs in solution results from reactions which form pollucite and/or CsAlSiO/sub 4/, with the production of pollucite exceeding that of CsAlSiO/sub 4/. Dissolution of ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ implies solubilizing a uranium species to an undetermined extent. The production of schoepite (UO/sub 3/.3H/sub 2/O) during some experiments containing basalt phases, indicates a tendency to oxidize U/sup 4 +/ to U/sup 6 +/. When diopside (nominally CaMgSi/sub 2/O/sub 6/) and ..beta..-Cs/sub 2/U/sub 2/O/sub 7/ were hydrothermally reacted, at 300/sup 0/C both UO/sub 2/ and UO/sub 3/.3H/sub 2/O were produced. Results of experiments on SrZrO/sub 3/ show it to be

  4. Hydrothermal interactions of cesium and strontium phases from spent unreprocessed fuel with basalt phases and basalts

    International Nuclear Information System (INIS)

    Komarneni, S.; Scheetz, B.E.; McCarthy, G.J.; Coons, W.E.

    1980-03-01

    This investigation is a segment of an extensive research program aimed at investigating the feasibility of long-term, subsurface storage of commercial nuclear waste. Specifically, it is anticipated that the waste will be housed in a repository mined from the basalt formations which lie beneath the Hanford Site. The elements monitored during the present experiments were Cs and Sr. These two elements represent significant biohazards if released from a repository and are the major heat producing radionuclides present in commercial radioactive waste. Several Cs phases and/or solutions were reacted with either isolated basalt phases or bulk-rock basalt, and the resulting solids and solutions were analyzed. The hydrothermal reactivity of SrZrO 3 , which is believed to be a probable host for Sr in SFE was investigated. While so far no evidence exists which indicates that Sr is present in a water soluble phase in spent fuel elements (SFE), detailed investigation of a potential hazard is warranted. This investigation has determined that some Cs compounds likely to be stable components of spent fuel (i.e., CsOH, Cs 2 MoO 4 , Cs 2 U 2 O 7 ) have significant hydrothermal solubilities. These solubilities are greatly decreased in the presence of basalt and/or basalt minerals. The decrease in the amount of Cs in solution results from reactions which form pollucite and/or CsAlSiO 4 , with the production of pollucite exceeding that of CsAlSiO 4 . Dissolution of β-Cs 2 U 2 O 7 implies solubilizing a uranium species to an undetermined extent. The production of schoepite (UO 3 .3H 2 O) during some experiments containing basalt phases, indicates a tendency to oxidize U 4+ to U 6+ . When diopside (nominally CaMgSi 2 O 6 ) and β-Cs 2 U 2 O 7 were hydrothermally reacted, at 300 0 C both UO 2 and UO 3 .3H 2 O were produced. Experiments on SrZrO 3 show it to be an unreactive phase

  5. Sulfur, Chlorine and Fluorine Degassing and Atmospheric Loading by the Roza eruption, Columbia River Basalt Group, Washington

    Science.gov (United States)

    Thordarson, Th.; Self, S

    1996-01-01

    In this study we attempt to quantify the amount of S, Cl and F released by the 1300 cu km Roza member (approximately 14.7 Ma) of the Columbia River Basalt Group, which was produced by a moderate-size flood basalt eruption in the mid-Miocene. Our results are the first indication of the potential atmospheric SO2 yield from a flood basalt eruption, and indicate the mechanism by which flood basalt eruptions may have seriously affected the environment. Glass inclusions in phenocrysts and quenched glass in products from various stages of the eruption were analyzed for concentrations of S, Cl and F and major elements. Glass inclusions contain 1965 +/- 110 ppm S, 295 +/- 65 ppm Cl and 1310 +/- 110 ppm F. Groundmass glass of Roza dike selvages contains considerably lower concentrations: 1110 +/- 90 ppm S, 245 +/- 30 ppm Cl and 1020 +/- 25 ppm F. Scoria clasts from near vent deposits contain 665 +/- 75 ppm S, 175 +/- 5 ppm Cl and 950 +/- 20 ppm F, and the groundmass glass of lava selvages contains 520 +/- 30 ppm S, 190 +/- 30 ppm Cl and 890 +/- 55 ppm F. In crystalline lava, the concentrations are 195 ppm S, 100 ppm Cl and 830 ppm F. Volatile element concentrations in these samples represent the progress of degassing through the eruption and can be used to estimate the potential amount of the volatiles S, Cl and F released by the magma into the atmosphere, as well as to evaluate the amount liberated by various phases of the eruption. The total amount of volatiles released by the Roza eruption is estimated to have been approximately 12,420 MtSO2, approximately 710 MtHCI and approximately 1780 MtHF. The Roza magma liberated approximately 9620 MtSO, (77% of the total volatile mass released), approximately 400 MtHCI (56%) and approximately 1450 MtHF (81%) at the vents and lofted by the eruption columns to altitudes of 7-13 km. Degassing of the lava is estimated to have released an additional approximately 2810 MtSO2, approximately 310 MtHCI and approximately 330 MtHF. The Roza

  6. Helium Isotope Variations in Basalts Along Gakkel Ridge and Heterogeneity of the Arctic Upper Mantle

    Science.gov (United States)

    Graham, D. W.; Lupton, J. E.; Goldstein, S. L.; Langmuir, C. H.; Michael, P. J.

    2009-12-01

    We report helium isotope compositions, determined by crushing in vacuum to release the gas trapped in vesicles, for 57 basalt glasses from the ultra-slow spreading Gakkel Ridge. Other geochemical data, especially radiogenic isotopes (Pb, Nd, Sr) reveal the presence of an isotopic boundary in the mid-section of this ridge that separates basalts in the west (west of 14°E longitude) having “Indian Ocean” (Dupal) isotopic signatures, from basalts in the east which resemble the North Atlantic/Pacific domain (Goldstein et al. 2008). This boundary reflects heterogeneity in the underlying mantle related to the tectonic history of continental land masses surrounding the Arctic Ocean. In the west there is a narrow range of 3He/4He with lower values (7.0-7.9 RA), while in the east there is a wider range of 3He/4He with higher values (7.9-9.3 RA) and effectively no overlap with the western group. Off-axis lavas do not fit this simple picture however, revealing some systematic temporal variability, perhaps associated with mantle flow beneath the ridge. All Gakkel Ridge basalts are deeply erupted and most have high helium contents, in some cases at the upper end of the MORB range (>50 μccSTP/g). The few exceptions, having He contents below 0.1 μccSTP/g, have the highest 3He/4He (>8.8 RA). This effect appears to reflect earlier (recent) melting of isotopically heterogeneous mantle, during which the initial melt fractions were slightly enriched in 4He, perhaps due to a larger modal contribution of clinopyroxene and/or garnet to those melts. The temporal variability and the melting effects, while significant, do not account for the large 3He/4He signal observed along the ridge axis. Overall, 3He/4He shows systematic covariation with other isotopic indicators of mantle heterogeneity (Pb, Nd, Sr and Hf), indicating that the helium isotope variations are a long-lived feature of the Arctic upper mantle. The 3He/4He ratio is as effective a discriminant of eastern and western

  7. Conversion of radioactive ferrocyanide compounds to immobile glasses

    International Nuclear Information System (INIS)

    Schulz, W.W.; Dressen, A.L.

    1977-01-01

    Complex radioactive ferrocyanide compounds result from the scavenging of cesium from waste products produced in the chemical reprocessing of nuclear fuel. These ferrocyanides, in accordance with this process, are converted to an immobile glass, resistant to leaching by water, by fusion together with sodium carbonate and a mixture of (a) basalt and boron trioxide (B 2 O 3 ) or (b) silica (SiO 2 ) and lime (CaO). 7 claims

  8. Rheological evolution of planetary basalts during cooling and crystallization

    Science.gov (United States)

    Sehlke, Alexander

    Basaltic lavas cover large portions of the surface of the Earth and other planets and moons. Planetary basalts are compositionally different from terrestrial basalts, and show a variety of unique large-scale lava flow morphologies unobserved on Earth. They are usually assumed to be much more fluid than basalts on Earth, such as Hawaiian basalt, but their rheology is largely unknown. I synthesized several synthetic silicate melts representing igneous rock compositions of Mars, Mercury, the Moon, Io and Vesta. I measured their viscosity, as well as several terrestrial lavas including Hawaiian basalt, by concentric cylinder and parallel plate viscometry. Planetary melts cover a wide range of viscosity at their liquidus, overlapping with terrestrial basaltic melts. I derived a new viscosity model that is based on the Adam-Gibbs theory of structural relaxation, predicting these viscosities much more accurately than previously published viscosity models. During crystallization, the rheological behavior changes from Newtonian to pseudoplastic. Combining rheology experiments with field observations, the rheological conditions of the pahoehoe to `a`a morphological transition for Hawaiian basalt were determined in strain rate-viscosity space. This transition occurs at temperatures around 1185+/-15°C. For Mercurian lavas, this transition is predicted to occur at higher temperatures around 1250+/-30°C. We find that the rheology of these lavas is broadly similar to terrestrial ones, suggesting that the large smooth volcanic plains observed on Mercury's northern hemisphere are due to flood basalt volcanism rather than unusually fluid lavas. We also show that KREEP lavas, a type of basalt associated with sinuous rilles on the lunar surface, is more likely to form rilles through levee construction, as the high and rapidly increasing viscosity prohibits sufficient thermo-mechanical erosion.

  9. Petrology of Gakkel Ridge Basalts: Preliminary Results

    Science.gov (United States)

    Langmuir, C. H.; Lehnert, K.; Goldstein, S. L.; Michael, P.; Graham, D.; Schramm, B.

    2001-12-01

    The Gakkel Ridge offers the opportunity for a direct experiment in mantle melting and ridge dynamics. It is the slowest spreading ridge on the Earth, with a progressive change in spreading rate from 15mm/yr at the western end to 7mm/yr at the eastern end. No transform faults disrupt the melting regime, and spreading rate alone would appear to be the primary variable. During the AMORE2001 expedition of USCGC Healy and RV Polarstern, more than one hundred sampling stations were successfully completed mid-way through the cruise, with precise locations on new multibeam bathymetric charts (Kurras et al, Gauger et al, this meeting). More than 100 samples were analyzed on board for major elements, Sr and Ba by direct current plasma spectrometry. Because the cruise track encompasses a double-pass along most of the ridge, the on board data permitted testing of hypotheses formulated on the first pass by further sampling on the second pass. Models for the effect of decreasing spreading rate on melt composition predict progressively smaller extents of melting at greater depths eastward along the ridge. Instead, the ridge contains three distinct tectono-magmatic regimes. In the west, well-defined linear volcanic ridges occupy the center of the rift valley. The basalts exhibit a ''slow spreading local trend'' of negative correlation between Fe8 and Si8 and positive correlation between Na8 and Fe8. There is a well-defined geochemical gradient from more enriched incompatible trace element compositions in the west to depleted compositions in the east. At the eastern terminus of this region there are small volcanic cones with chemical compositions rare or unique among MORB. Samples with high MgO contain high TiO2 and Sr (3% and 200 ppm), and low SiO2 and Ba (46-47% and 20 ppm ). The low SiO2 and exceptionally high FeO (12%) suggest high pressures of melting. The high Sr and TiO2 but very low Ba of these samples suggest they were derived by very low extents of melting of a depleted

  10. Vesiculation of basaltic magma during eruption

    Science.gov (United States)

    Mangan, Margaret T.; Cashman, Katharine V.; Newman, Sally

    1993-01-01

    Vesicle size distributions in vent lavas from the Pu'u'O'o-Kupaianaha eruption of Kilauea volcano are used to estimate nucleation and growth rates of H2O-rich gas bubbles in basaltic magma nearing the earth's surface (≤120 m depth). By using well-constrained estimates for the depth of volatile exsolution and magma ascent rate, nucleation rates of 35.9 events ⋅ cm-3 ⋅ s-1 and growth rates of 3.2 x 10-4cm/s are determined directly from size-distribution data. The results are consistent with diffusion-controlled growth as predicted by a parabolic growth law. This empirical approach is not subject to the limitations inherent in classical nucleation and growth theory and provides the first direct measurement of vesiculation kinetics in natural settings. In addition, perturbations in the measured size distributions are used to examine bubble escape, accumulation, and coalescence prior to the eruption of magma.

  11. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

    Burton, K. W.; Parkinson, I. J.; Gíslason, S. G. R.

    2016-12-01

    The strontium (Sr) stable isotope composition of rivers is strongly controlled by the balance of carbonate to silicate weathering (Krabbenhöft et al. 2010; Pearce et al. 2015). However, rivers draining silicate catchments possess distinctly heavier Sr stable isotope values than their bedrock compositions, pointing to significant fractionation during weathering. Some have argued for preferential release of heavy Sr from primary phases during chemical weathering, others for the formation of secondary weathering minerals that incorporate light isotopes. This study presents high-precision double-spike Sr stable isotope data for soils, rivers, ground waters and estuarine waters from Iceland, reflecting both natural weathering and societal impacts on those environments. The bedrock in Iceland is dominantly basaltic, d88/86Sr ≈ +0.27, extending to lighter values for rhyolites. Geothermal waters range from basaltic Sr stable compositions to those akin to seawater. Soil pore waters reflect a balance of input from primary mineral weathering, precipitation and litter recycling and removal into secondary phases and vegetation. Rivers and ground waters possess a wide range of d88/86Sr compositions from +0.101 to +0.858. Elemental and isotope data indicate that this fractionation primarily results from the formation or dissolution of secondary zeolite (d88/86Sr ≈ +0.10), but also carbonate (d88/86Sr ≈ +0.22) and sometimes anhydrite (d88/86Sr ≈ -0.73), driving the residual waters to heavier or lighter values, respectively. Estuarine waters largely reflect mixing with seawater, but are also be affected by adsorption onto particulates, again driving water to heavy values. Overall, these data indicate that the stability and nature of secondary weathering phases, exerts a strong control on the Sr stable isotope composition of silicate rivers. [1] Krabbenhöft et al. (2010) Geochim. Cosmochim. Acta 74, 4097-4109. [2] Pearce et al. (2015) Geochim. Cosmochim. Acta 157, 125-146.

  12. BASALT A: Basaltic Terrains in Idaho and Hawaii as Planetary Analogs for Mars Geology and Astrobiology

    Science.gov (United States)

    Hughes, Scott S.; Haberle, Christopher W.; Nawotniak, Shannon E. Kobs; Sehlke, Alexander; Garry, W. Brent; Elphic, Richard C.; Payler, Sam J.; Stevens, Adam H.; Cockell, Charles S.; Brady, Allyson L.; hide

    2018-01-01

    Assessments of field research target regions are described within two notably basaltic geologic provinces as Earth analogs to Mars. Regions within the eastern Snake River Plain of Idaho and the Big Island of Hawaii, USA, provinces that represent analogs of present-day and early Mars, respectively, were evaluated on the basis of geologic settings, rock lithology and geochemistry, rock alteration, and climate. Each of these factors provide rationale for the selection of specific targets for field research in five analog target regions: (1) Big Craters and (2) Highway lava flows at Craters of the Moon National Monument and Preserve, Idaho; and (3) Mauna Ulu low shield, (4) Kilauea Iki lava lake and (5) Kilauea caldera in the Kilauea Volcano summit region and the East Rift Zone of Hawaii. Our evaluation of compositional and textural differences, as well as the effects of syn- and post-eruptive rock alteration, shows that the basaltic terrains in Idaho and Hawaii provide a way to characterize the geology and major geologic substrates that host biological activity of relevance to Mars exploration. This work provides the foundation to better understand the scientific questions related to the habitability of basaltic terrains, the rationale behind selecting analog field targets, and their applicability as analogs to Mars.

  13. Alteration of national glass in radioactive waste repository host rocks: A conceptional review

    International Nuclear Information System (INIS)

    Apps, J.A.

    1987-01-01

    The storage of high-level radioactive wastes in host rocks containing natural glass has potential chemical advantages, especially if the initial waste temperatures are as high as 250 0 C. However, it is not certain how natural glasses will decompose when exposed to an aqueous phase in a repository environment. The hydration and devitrification of both rhyolitic and natural basaltic natural glasses are reviewed in the context of hypothetical thermodynamic phase relations, infrared spectroscopic data and laboratory studies of synthetic glasses exposed to steam. The findings are compared with field observations and laboratory studies of hydrating and devitrifying natural glasses. The peculiarities of the dependence of hydration and devitrification behavior on compositional variation is noted. There is substantial circumstantial evidence to support the belief that rhyolitic glasses differ from basaltic glasses in their thermodynamic stability and their lattice structure, and that this is manifested by a tendency of the former to hydrate rather than devitrify when exposed to water. Further research remains to be done to confirm the differences in glass structure, and to determine both physically and chemically dependent properties of natural glasses as a function of composition

  14. Conversion of Hanford salt cake to glass: laboratory studies

    International Nuclear Information System (INIS)

    Schulz, W.W.; Dressen, A.L.; Hobbick, C.W.; Kupfer, M.J.

    1976-05-01

    Approximately 140 million liters of solid salt cake (mainly NaNO 3 ), produced by evaporation of aged, alkaline high-level wastes, will be stored in underground tanks when the present Hanford Waste Management Program is completed in the early 1980's. These solid wastes can be converted to silicate-based glasses by melting them either at 1200 to 1300 0 C with appropriate amounts of sand and lime (soda-lime formulation) or at 1000 to 1100 0 C with appropriate amounts of Columbia River basalt and B 2 O 3 (basalt formulation). Both formulations yield dense, immobile glasses of low water leachability (10 -7 to 10 -6 g cm -2 day -1 ) suitable for terminal storage. The soda-lime formulation is presently preferred over the basalt formulation because it can accommodate more salt cake (50 wt percent versus 30 to 40 wt percent) while yielding a glass whose volume is 10 to 20 percent less than the volume of the salt cake in the melt charge

  15. Simulated high-level waste-basalt interaction experiments. Annual progress report, October 1, 1977--September 30, 1978

    International Nuclear Information System (INIS)

    Scheetz, B.E.; Smith, D.K.; Barnes, M.W.; Komarneni, S.; Stull, L.M.; Smith, C.A.

    1978-11-01

    Reconnaissance experiments suggested that the observed reactivity of calcine and glass as 300 0 C would be anticipated at lower temperatures but only after longer times of hydrothermal treatment. Long-duration experiments at 100 0 and 300 0 C were initiated to determine the time dependence of the alterations at lower temperatures. The reconnaissance experiments also suggested that equilibrium conditions were not yet achieved in these closed system experiments. Glass was observed to alter readily with the formation of acmite-augite pyroxene; a uranyl silicate, weeksite; and a rare-earth slicate-phosphate hydroxyapatite. Nearly all of the B, ca. 70% of the Mo and ca. 50% of the Na in the original glass were dissolved. A simulated reduced SURF (spent unreprocessed fuel) was utilized in hydrothermal experiments. Analyses of the solutions confirmed that soluble fission products phases were leached from the UO 2 matrix and all of the alkali metals were leached from the SURF. In the presence of basalt, however, the released alkalis react with aluminosilicates and are removed from solution. Individual phases believed to be present in SURF have been hydrothermally treated, with the reference basalts and with major primary and secondary minerals. Cs(OH), Cs 2 MoO 4 and Cs 2 U 2 O 7 were used as potential cesium phases. In some cases as much as 99.9% of the cesium can be removed from solution by interacting with the rocks and minerals to form pollucite. The interaction of strontium zirconate under hydrothermal conditions with the above rock and basalt minerals indicates that in all cases 99.9% of the available strontium is retained in the strontium zirconate or as alteration products. 11 figures, 8 tables

  16. Sardinian basalt. An ancient georesource still en vougue

    Science.gov (United States)

    Careddu, Nicola; Grillo, Silvana Maria

    2017-04-01

    Commercially quarried Sardinian basalt was the result of extensive volcanic activity during the Pliocene and Pleistocene ages, following the opening of the Campidano plain and Tyrrhenian sea rift. Extensive areas of Sardinia have been modelled by large volumes of basalt and andesite rock. An example is provided by the 'Giare' tablelands and other large plateaus located in central Sardinia. Other basalt-rich areas exist in the Island. Sardinia is featured by a vast array of basalt monuments, dating back to the II-I millennium BC, bearing witness to the great workability, durability and resistance to weathering of the rock. The complex of circular defensive towers, known as "Su Nuraxi di Barumini" was included in the World Heritage List by Unesco in 1997. Basalt is currently produced locally to be used for architectural and ornamental purposes. It is obtained by quarrying stone deposits or mining huge boulders which are moved and sawn by means of mechanical machinery. Stone-working is carried out in plants located in various sites of the Island. The paper begins with an historical introduction and then focusses on the current state of the art of Sardinian basalt quarrying, processing and using. An analysis of the basalt market has been carried out.

  17. Records of upper mantle oxygen fugacity gleaned from high-density sampling of basalts and peridotites at ultraslow ridges

    Science.gov (United States)

    Birner, S.; Cottrell, E.; Warren, J. M.; Kelley, K. A.; Davis, F. A.

    2016-12-01

    Mantle oxygen fugacity (fO2) controls volatile speciation, phase stability, and the depth of the peridotite solidus, and is thus critical to our understanding of melt production at mid-ocean ridges. Both basalts [1] and peridotites [2] have been used as proxies for calculating upper mantle fO2 beneath ridges. Though the global peridotite dataset for fO2 is limited and does not overlap geographically with samples from the more comprehensive global basalt dataset, the average fO2 recorded by peridotites is lower than that recorded by basalts. Ultraslow spreading ridges such as the Southwest Indian Ridge (SWIR) and Gakkel Ridge have limited magma production due to thick conductive cooling lids at the ridge axis, and thus offer a unique opportunity to compare geographically overlapping suites of basalt and peridotite. In this study, we determined the oxygen fugacity of 41 peridotite samples from the Oblique Segment of SWIR and 10 peridotite samples from Gakkel - more than doubling the number of fO2 estimates for ridge peridotites globally. Our results for SWIR show that peridotite fO2 is highly variable on the dredge to sub-segment scale, ranging from 1.7 log units below the quartz-fayalite-magnetite buffer (QFM) to 1 log unit above QFM, with an average of QFM+0.2 (±0.6). We also calculated fO2 for 25 basalt glasses from the Oblique Segment, which have an average fO2 of QFM+0.3 (±0.1). Importantly, on average, we find no offset between mantle fO2 as recorded by basalts versus peridotites. However, fO2 recorded by basalts is significantly more homogenous than by peridotites, consistent with the idea of aggregate melts recording homogenization of a heterogeneous mantle. The most reduced peridotites at both ridges are generally highly refractory samples at high spinel Cr# (Cr# = Cr/(Cr+Al)) and low modal cpx. This suggests that the process of melt extraction may leave behind a reduced residue. Alternatively, if these highly refractory lithologies are residues from

  18. The Thickness and Volume of Young Basalts Within Mare Imbrium

    Science.gov (United States)

    Chen, Yuan; Li, Chunlai; Ren, Xin; Liu, Jianjun; Wu, Yunzhao; Lu, Yu; Cai, Wei; Zhang, Xunyu

    2018-02-01

    Basaltic volcanism is one of the most important geologic processes of the Moon. Research on the thickness and volume of late-stage basalts of Mare Imbrium helps better understand the source of lunar volcanism and eruption styles. Based on whether apparent flow fronts exist or not, the late-stage basalts within Mare Imbrium were divided into two groups, namely, Upper Eratosthenian basalts (UEm) and Lower Eratosthenian basalts (LEm). Employing the topographic profile analysis method for UEm and the crater excavation technique for LEm, we studied the thickness and distribution of Eratosthenian basalts in Mare Imbrium. For the UEm units, their thicknesses were estimated to be 16-34 (±2) m with several layers of individual lava ( 8-13 m) inside. The estimated thickness of LEm units was 14-45(±1) m, with a trend of reducing thickness from north to south. The measured thickness of late-stage basalts around the Chang'E-3 landing site ( 37 ± 1 m) was quite close to the results acquired by the lunar penetrating radar carried on board the Yutu Rover ( 35 m). The total volume of the late-stage basalts in Mare Imbrium was calculated to be 8,671 (±320) km3, which is 4 times lower than that of Schaber's estimation ( 4 × 104 km3). Our results indicate that the actual volume is much lower than previous estimates of the final stage of the late basaltic eruption of Mare Imbrium. Together, the area flux and transport distance of the lava flows gradually decreased with time. These results suggest that late-stage volcanic evolution of the Moon might be revised.

  19. Basaltic volcanic episodes of the Yucca Mountain region

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M.

    1990-03-01

    The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs.

  20. Influence of pyrolysis temperature on fracture response in SiOC based composites reinforced by basalt woven fabric

    Czech Academy of Sciences Publication Activity Database

    Chlup, Zdeněk; Černý, Martin; Strachota, Adam; Sucharda, Zbyněk; Halasová, Martina; Dlouhý, Ivo

    2014-01-01

    Roč. 34, č. 14 (2014), s. 3389-3398 ISSN 0955-2219 R&D Projects: GA ČR GAP107/12/2445; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 ; RVO:67985891 ; RVO:61389013 Keywords : Fracture behaviour * CMCs * Pyrolysis * Basalt fibre * Polysiloxane Subject RIV: JL - Materials Fatigue, Friction Mechanics; JI - Composite Materials (USMH-B); JH - Ceramics, Fire-Resistant Materials and Glass (UMCH-V) Impact factor: 2.947, year: 2014

  1. Spreading and collapse of big basaltic volcanoes

    Science.gov (United States)

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael

    2016-04-01

    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  2. Applications of iron-enriched basalt to TMI radioactive waste disposal

    International Nuclear Information System (INIS)

    Owen, D.E.; Welch, J.M.; Kelsey, P.V.; Flinn, J.E.

    1982-01-01

    Iron-enriched basalt (IEB), a man-made analogue to natural basalt, has been investigated as a dissolution and immobilization medium for Three Mile Island (TMI) radioactive wastes. The research has focused on the ability of IEB, a glass-ceramic whose principal constituents are SiO 2 , Fe 2 O 3 + FeO, and Al 2 O 3 , to contain TMI zeolites, resins, and core debris; and on the practical aspects of producing IEB on a large scale using a joule-heated melter. The retention of cesium and strontium during high-temperature processing of IEB and the leach rate of these species from IEB in 363 K deionized water have been investigated. Simulated TMI core debris (UO 2 , zircaloy, and stainless steel) have been successfully dissolved in IEB by using an air bubbler to accelerate the dissolution process. Large-scale IEB castings (10 kg and 75 kg) incorporating simulated TMI wastes have been prepared using a 250 kg capacity joule-heated research melter. Subjecting the castings to a controlled cooling produced fine grained monoliths with almost no microcracks. 6 figures

  3. Radiogenic isotopes in enriched mid-ocean ridge basalts from Explorer Ridge, northeast Pacific Ocean

    Science.gov (United States)

    Cousens, Brian; Weis, Dominique; Constantin, Marc; Scott, Steve

    2017-09-01

    Extreme gradients in topography related to variations in magma supply are observed on the Southern Explorer Ridge (SER), part of the northern Juan de Fuca ridge system. We report radiogenic isotope (Pb, Sr, Nd, Hf) and geochemical data for twenty-four basalt whole-rock and glass samples collected from the length of the SER and from Explorer Deep, a rift to the north of the SER. Lavas from the SER form a north-south geochemical gradient, dominated by E-MORB at the northern axial high, and range from T-MORB to N-MORB towards the southern deepest part of the ridge. Linear relationships between incompatible element ratios and isotopic ratios in MORB along the ridge are consistent with mixing of magmas beneath the ridge to generate the geographic gradient from E- to N-MORB. The E-MORB have high Sr and Pb, and low Nd and Hf isotopic ratios, typical of enriched mantle that includes a FOZO or HIMU isotopic component. The West Valley and Endeavour segments of the northern Juan de Fuca ridge also include this isotopic component, but the proportion of the FOZO or HIMU component is more extreme in the SER basalts. The FOZO or HIMU component may be garnet-bearing peridotite, or a garnet pyroxenite embedded in peridotite. Recycled garnet pyroxenite better explains the very shallow SER axial high, high Nb/La and La/Sm, and the ;enriched; isotopic compositions.

  4. Immiscible iron- and silica-rich melt in basalt petrogenesis documented in the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Jakobsen, Jakob Kløve; Veksler, Ilya; Tegner, Christian

    2005-01-01

    Silicate liquid immiscibility in basalt petrogenesis is a contentious issue. Immiscible iron and silica-rich liquids were reported in melt inclusions of lunar basalt and in groundmass glasses of terrestrial volcanics. In fully crystallized plutonic rocks, however, silicate liquid immiscibility has...... colored type contains 30.9 6 4.2 wt% FeOt and 40.7 6 3.6 wt% SiO2, whereas the light colored type contains 8.6 6 5.9 wt% FeOt and 65.6 6 7.3 wt% SiO2. Similar light colored melt inclusions in olivine and fine grained dark and light colored interstitial pockets also give evidence of crystallization from...... petrogenesis. Some granitic rocks may represent unmixed silica-rich melt, whereas the dense, iron-rich melt is likely to sink in the crust and could mix with hot mantle-derived magma to form unusual rocks, like ferropicrites, otherwise interpreted as products of heterogeneous mantle sources....

  5. Property and process correlations for iron-enriched basalt waste forms

    International Nuclear Information System (INIS)

    Grandy, J.D.; Eddy, T.L.; Anderson, G.L.

    1993-02-01

    Correlations of thermodynamic properties and process parameters of high-temperature slag for a range of compositions of iron-enriched basalt are presented. The quantification of the properties of this complex mixture can assist in the design and monitoring of high-temperature melting systems for the treatment of radioactive and hazardous wastes at the Idaho National Engineering Laboratory. The buried and stored wastes at the INEL Radioactive Waste Management Complex have a similar composition to iron-enriched basalt after oxidation of organics. The properties correlated are the viscosity, electrical conductivity, refractory corrosion, and recrystallization temperature. The correlations are expressed as a function of input waste-soil mixture composition, alkali concentration, and slag temperature. An application to determine the effect of alkali flux on slag temperature, leach rate, and volume reduction is presented. Though the correlations are for mixtures of soil and waste with average transuranic-contaminated waste compositions, it appears that good approximations for other waste streams and glass-ceramic waste forms can be obtained because of similarities in composition

  6. Interaction of groundwater and fresh basalt fissure surfaces and its effect on the migration of actinides

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Bowers, D.L.; Gerding, T.J.; Fried, S.M.; Wilbur, C.K.; Seitz, M.G.

    1983-01-01

    Experiments are being performed at Argonne National Laboratory (ANL): (1) to identify interactions of radionuclides and repository components that effect nuclide migration, and (2) to assess changes in nuclide migration caused by modifications expected upon aging of the waste, clay backfill, and rock. The experiments are conducted with radioactive borosilicate glass, bentonite and mechanically fissured basalt rock in flowing water analogous to their configuration in a breach of a nuclear waste repository. Changes undergone by the groundwater as it passed through the fissure include: (1) drop in pH from 10 to 8, (2) loss of suspended particulate, and (3) loss of dissolved/suspended U, Np, and Pu. These effects, also studied as functions of radiation dose and of laboratory aging of the repository components, are related to the predicted long-term performance of a nuclear waste repository

  7. Hafnium isotope variations in oceanic basalts

    Science.gov (United States)

    Patchett, P. J.; Tatsumoto, M.

    1980-01-01

    Hafnium isotope ratios generated by the beta(-) decay of Lu-176 are investigated in volcanic rocks derived from the suboceanic mantle. Hf-176/Hf-177 and Lu/Hf ratios were determined to precisions of 0.01-0.04% and 0.5%, respectively, by routine, low-blank chemistry. The Hf-176/Hf-177 ratio is found to be positively correlated with the Nd-143/Nd-144 ratio and negatively correlated with the Sr-87/Sr-86 and Pb-206/Pb-204 ratios, and to increase southwards along the Iceland-Reykjanes ridge traverse. An approximate bulk earth Hf-176/Hf-177 ratio of 0.28295 is inferred from the bulk earth Nd-143/Nd-144 ratio, which requires a bulk earth Lu/Hf ratio of 0.25, similar to the Juvinas eucrite. Midocean ridge basalts are shown to account for 60% of the range of Hf isotope ratios, and it is suggested that Lu-Hf fractionation is decoupled from Sm-Nd and Rb-Sr fractionation in very trace-element-depleted source regions as a result of partial melting.

  8. Magnesium-rich Basalts on Mercury

    Science.gov (United States)

    Martel, L. M. V.

    2013-05-01

    X-ray and gamma-ray spectrometers on NASA's MESSENGER spacecraft are making key measurements regarding the composition and properties of the surface of Mercury, allowing researchers to more clearly decipher the planet's formation and geologic history. The origin of the igneous rocks in the crust of Mercury is the focus of recent research by Karen Stockstill-Cahill and Tim McCoy (National Museum of Natural History, Smithsonian Institution), along with Larry Nittler and Shoshana Weider (Carnegie Institution of Washington) and Steven Hauck II (Case Western Reserve University). Using the well-known MELTS computer code Stockstill-Cahill and coauthors worked with MESSENGER-derived and rock-analog compositions to constrain petrologic models of the lavas that erupted on the surface of Mercury. Rock analogs included a partial melt of the Indarch meteorite and a range of Mg-rich terrestrial rocks. Their work shows the lavas on Mercury are most similar to terrestrial magnesian basalt (with lowered FeO content). The implications of the modeling are that Mg-rich lavas came from high-temperature sources in Mercury's mantle and erupted at high temperature with exceptionally low viscosity into thinly bedded and laterally extensive flows, concepts open to further evaluation by laboratory experiments and by geologic mapping of Mercury's surface using MESSENGER's imaging system and laser altimeter to document flow features and dimensions.

  9. Basalt FRP Spike Repairing of Wood Beams

    Directory of Open Access Journals (Sweden)

    Luca Righetti

    2015-08-01

    Full Text Available This article describes aspects within an experimental program aimed at improving the structural performance of cracked solid fir-wood beams repaired with Basalt Fiber Reinforced Polymer (BFRP spikes. Fir wood is characterized by its low density, low compression strength, and high level of defects, and it is likely to distort when dried and tends to fail under tension due to the presence of cracks, knots, or grain deviation. The proposed repair technique consists of the insertion of BFRP spikes into timber beams to restore the continuity of cracked sections. The experimental efforts deal with the evaluation of the bending strength and deformation properties of 24 timber beams. An artificially simulated cracking was produced by cutting the wood beams in half or notching. The obtained results for the repaired beams were compared with those of solid undamaged and damaged beams, and increases of beam capacity, bending strength and of modulus of elasticity, and analysis of failure modes was discussed. For notched beams, the application of the BFRP spikes was able to restore the original bending capacity of undamaged beams, while only a small part of the original capacity was recovered for beams that were cut in half.

  10. Crystallization In Multicomponent Glasses

    International Nuclear Information System (INIS)

    Kruger, A.A.; Hrma, P.R.

    2009-01-01

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  11. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HRMA PR

    2009-10-08

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  12. Engineered barrier development for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    The BWIP Engineered Barrier Program has been developed to provide an integrated approach to the development of site-specific Engineered Barrier assemblages for a repository located in basalt. The goal of this program is to specify engineered and natural barriers which will ensure that nuclear and non-radioactive hazardous materials emplaced in a repository in basalt do not exceed acceptable rates of release to the biosphere. A wide range of analytical and experimental activities related to the basalt repository environment, waste package environment, waste/barrier/rock interactions, and barrier performance assessment provide the basis for selection of systems capable of meeting licensing requirements. Work has concentrated on specifying and testing natural and man-made materials which can be used to plug boreholes in basalt and which can be used as multiple barriers to surround nuclear waste forms and containers. The Engineered Barriers Program is divided into two major activities: multiple barrier studies and borehole plugging. 8 figures, 4 tables

  13. Laser Ar-39-Ar-40 study of Apollo 17 basalts

    Science.gov (United States)

    Schaeffer, O. A.; Mueller, H. W.; Grove, T. L.

    1977-01-01

    Three Apollo 17 basalts were studied by the laser Ar-39-Ar-40 method. The 70215 basalt has a normal well-behaved Ar-39-Ar-40 release pattern; the 70017 basalt has a disturbed release pattern which indicates a limited intermediate maximum age followed by a broad low-age region; and the 75035 basalt has a pattern initially similar to 70017 that is followed by a high-temperature maximum age. The laser study shows that all mineral systems in 70215 have small and uniform temperature losses, while the laser-determined ages for 70017 and 75035 are, apparently, primarily controlled by the minerals containing mesostasis inclusions. It is possible that the drop in ages observed by the conventional Ar-39-Ar-40 method was due not only to recoil of Ar-39 during neutron irradiation but also to gas loss from some minerals. It is suggested that the plagioclases are the best minerals to use for a reliable age.

  14. Impact Strength of Glass and Glass Ceramic

    Science.gov (United States)

    Bless, S.; Tolman, J.

    2009-12-01

    Strength of glass and glass ceramic was measured with a bar impact technique. High-speed movies show regions of tensile and compressive failure. The borosilicate glass had a compressive strength of at least 2.2 GPa, and the glass ceramic at least 4 GPa. However, the BSG was much stronger in tension than GC. In ballistic tests, the BSG was the superior armor.

  15. Chemical magnetization when determining Thellier paleointensity experiments in oceanic basalts

    Science.gov (United States)

    Tselebrovskiy, Alexey; Maksimochkin, Valery

    2017-04-01

    The natural remanent magnetization (NRM) of oceanic basalts selected in the rift zones of the Mid-Atlantic Ridge (MAR) and the Red Sea has been explored. Laboratory simulation shows that the thermoremanent magnetization and chemical remanent magnetization (CRM) in oceanic basalts may be separated by using Tellier-Coe experiment. It was found that the rate of CRM destruction is about four times lower than the rate of the partial thermoremanent magnetization formation in Thellier cycles. The blocking temperatures spectrum of chemical component shifted toward higher temperatures in comparison with the spectrum of primary thermoremanent magnetization. It was revealed that the contribution of the chemical components in the NRM increases with the age of oceanic basalts determined with the analysis of the anomalous geomagnetic field (AGF) and spreading theory. CRM is less than 10% at the basalts aged 0.2 million years, less than 50% at basalts aged 0.35 million years, from 60 to 80% at basalts aged 1 million years [1]. Geomagnetic field paleointensity (Hpl) has been determined through the remanent magnetization of basalt samples of different ages related to Brunhes, Matuyama and Gauss periods of the geomagnetic field polarity. The value of the Hpl determined by basalts of the southern segment of MAR is ranged from 17.5 to 42.5 A/m, by the Reykjanes Ridge basalts — from 20.3 to 44 A/m, by the Bouvet Ridge basalts — from 21.7 to 34.1 A/m. VADM values calculated from these data are in good agreement with the international paleointensity database [2] and PISO-1500 model [3]. Literature 1. Maksimochkin V., Tselebrovskiy A., (2015) The influence of the chemical magnetization of oceanic basalts on determining the geomagnetic field paleointensity by the thellier method, moscow university physics bulletin, 70(6):566-576, 2. Perrin, M., E. Schnepp, and V. Shcherbakov (1998), Update of the paleointensity database, Eos Trans. AGU, 79, 198. 3. Channell JET, Xuan C, Hodell DA (2009

  16. Geochemistry of the Potassic Basalts from the Bufumbira Volcanic ...

    African Journals Online (AJOL)

    The various basalts are low in SiO2 wt %, Al2O3 wt % and Na2O wt % but high in MgO wt %, TiO2 wt %, CaO wt %, K2O wt % with K2O/Na2O = 1.08 to 2.07. These are potassic belonging to the kamafugite series. Plots discriminate two geochemical trends corresponding to the picritic and clinopyroxene rich basalts.

  17. Radiolytic hydrogen production in the subseafloor basaltic aquifer

    Directory of Open Access Journals (Sweden)

    Mary E Dzaugis

    2016-02-01

    Full Text Available Hydrogen (H2 is produced in geological settings by dissociation of water due to radiation from radioactive decay of naturally occurring uranium (238U, 235U, thorium (232Th and potassium (40K. To quantify the potential significance of radiolytic H2 as an electron donor for microbes within the South Pacific subseafloor basaltic aquifer, we use radionuclide concentrations of 43 basalt samples from IODP Expedition 329 to calculate radiolytic H2 production rates in basement fractures. The samples are from three sites with very different basement ages and a wide range of alteration types. U, Th and K concentrations vary by up to an order of magnitude from sample to sample at each site. Comparison of our samples to each other and to the results of previous studies of unaltered East Pacific Rise basalt suggests that significant variations in radionuclide concentrations are due to differences in initial (unaltered basalt concentrations (which can vary between eruptive events and post-emplacement alteration. In our samples, there is no clear relationship between alteration type and calculated radiolytic yields. Local maxima in U, Th, and K produce hotspots of H2 production, causing calculated radiolytic rates to differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production, where microfractures are hotspots for radiolytic H2 production. For example, H2 production rates normalized to water volume are 190 times higher in 1 μm wide fractures than in fractures that are 10 cm wide. To assess the importance of water radiolysis for microbial communities in subseafloor basaltic aquifers, we compare electron transfer rates from radiolysis to rates from iron oxidation in subseafloor basalt. Radiolysis appears likely to be a more important electron donor source than iron oxidation in old (>10 Ma basement basalt. Radiolytic H2 production in the volume of water adjacent to a square cm of the most radioactive SPG basalt may

  18. PREDICTION OF BASALT FIBER REINFORCED CONCRETE PAVEMENT BENDING STRENGTH VALUES

    OpenAIRE

    Hidayet BAYRAKTAR; Ayhan SAMANDAR; Suat SARIDEMİR

    2017-01-01

    This paper proposes the potential of artificial neural network (ANN) system for estimating the bending strength values of the basalt fiber reinforced concrete pavements. Three main influential parameters; namely basalt fiber ratio, density and slump value of the fresh concrete were selected as input data. The model was trained, tested using 400 data sets which were the results of on-site experiment tests. ANN system results were also compared with the experimental test results. The research r...

  19. Insulation from basaltic stamp sand. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, F. D.

    1981-04-01

    A Midwest Appropriate Technology Grant was awarded to determine the technical and economic feasibility of producing mineral-fiber insulation directly from extensive deposits of basaltic sand produced during former mining and milling operations in the Keweenaw Peninsula region of Michigan's Upper Peninsula. The amounts of local basaltic sands available and representative chemical compositions were determined. The variation of viscosity with temperature and chemical composition was estimated. Samples were melted and either pulled or blown into fiber. In all cases fiber could be made with a reasonable tensile strength to ensure usefulness. It was concluded that it was technically feasible to produce fibers from basaltic stamp sands of the Upper Peninsula of Michigan. A technical feasibility study using published data, a cost and design analysis of a basalt fiber production plant, a market survey of fiber needs, and an economic analysis for investing in a basalt fiber venture was undertaken. These studies concluded that the local production of basaltic insulation was both feasible and economically reasonable. It was suggested that the plant be located in a region of greater population density with lower utility costs. A representative one-third of these studies is included as appendices A, B, C, and D.

  20. Plate tectonics and continental basaltic geochemistry throughout Earth history

    Science.gov (United States)

    Keller, Brenhin; Schoene, Blair

    2018-01-01

    Basaltic magmas constitute the primary mass flux from Earth's mantle to its crust, carrying information about the conditions of mantle melting through which they were generated. As such, changes in the average basaltic geochemistry through time reflect changes in underlying parameters such as mantle potential temperature and the geodynamic setting of mantle melting. However, sampling bias, preservation bias, and geological heterogeneity complicate the calculation of representative average compositions. Here we use weighted bootstrap resampling to minimize sampling bias over the heterogeneous rock record and obtain maximally representative average basaltic compositions through time. Over the approximately 4 Ga of the continental rock record, the average composition of preserved continental basalts has evolved along a generally continuous trajectory, with decreasing compatible element concentrations and increasing incompatible element concentrations, punctuated by a comparatively rapid transition in some variables such as La/Yb ratios and Zr, Nb, and Ti abundances approximately 2.5 Ga ago. Geochemical modeling of mantle melting systematics and trace element partitioning suggests that these observations can be explained by discontinuous changes in the mineralogy of mantle partial melting driven by a gradual decrease in mantle potential temperature, without appealing to any change in tectonic process. This interpretation is supported by the geochemical record of slab fluid input to continental basalts, which indicates no long-term change in the global proportion of arc versus non-arc basaltic magmatism at any time in the preserved rock record.

  1. Recycling of Glass

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    Glass is used for many purposes, but in the waste system glass is predominantly found in terms of beverage and food containers with a relatively short lifetime before ending up in the waste. Furthermore there is a large amount of flat glass used in building materials which also ends up in the waste...... system; this glass though has a long lifetime before ending up in the waste. Altogether these product types add up to 82% of the production of the European glass industry (IPCC, 2001). Recycling of glass in terms of cleaning and refilling of bottles as well as the use of broken glass in the production...... of new glass containers is well established in the glass industry. This chapter describes briefly howglass is produced and howwaste glass is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of glass recycling....

  2. Improving iron-enriched basalt with additions of ZrO{sub 2} and TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, G.A.; Kong, P.C.

    1993-06-01

    The iron-enriched basalt (IEB) waste form, developed at the Idaho National Engineering Laboratory a decade ago, was modified to IEB4 by adding sufficient ZrO{sub 2} and TiO{sub 2} to develop crystals of zirconolite upon cooling, in addition to the crystals that normally form in a cooling basalt. Zirconolite (CaZrTi{sub 2}O{sub 7}) is an extremely leach-resistant mineral with a strong affinity for actinides. Zirconolite crystals containing uranium and thorium have been found that have endured more than 2 billion years of natural processes. On this basis, zirconolite was considered to be an ideal host crystal for the actinides contained in transuranic (TRU)-contaminated wastes. Crystals of zirconolite were developed in laboratory melts of IEB4 that contained 5% each of ZrO{sub 2} and TiO{sub 2} and that were slow-cooled in the 1200--1000{degrees}C range. When actinide surrogates were added to IEB4, these oxides were incorporated into the crystals of zirconolite rather than precipitating in the residual glass phase. Zirconolite crystals developed in IEB4 should stabilize and immobilize the dilute TRUs in heterogeneous, buried low-level wastes as effectively as this same phase does in the various formulations of Synroc used for the more concentrated TRUs encountered in high-level wastes. Synroc requires hot-pressing equipment, while IEB4 precipitates zirconolite from a cooling basaltic melt.

  3. Improving iron-enriched basalt with additions of ZrO2 and TiO2

    International Nuclear Information System (INIS)

    Reimann, G.A.; Kong, P.C.

    1993-06-01

    The iron-enriched basalt (IEB) waste form, developed at the Idaho National Engineering Laboratory a decade ago, was modified to IEB4 by adding sufficient ZrO 2 and TiO 2 to develop crystals of zirconolite upon cooling, in addition to the crystals that normally form in a cooling basalt. Zirconolite (CaZrTi 2 O 7 ) is an extremely leach-resistant mineral with a strong affinity for actinides. Zirconolite crystals containing uranium and thorium have been found that have endured more than 2 billion years of natural processes. On this basis, zirconolite was considered to be an ideal host crystal for the actinides contained in transuranic (TRU)-contaminated wastes. Crystals of zirconolite were developed in laboratory melts of IEB4 that contained 5% each of ZrO 2 and TiO 2 and that were slow-cooled in the 1200--1000 degrees C range. When actinide surrogates were added to IEB4, these oxides were incorporated into the crystals of zirconolite rather than precipitating in the residual glass phase. Zirconolite crystals developed in IEB4 should stabilize and immobilize the dilute TRUs in heterogeneous, buried low-level wastes as effectively as this same phase does in the various formulations of Synroc used for the more concentrated TRUs encountered in high-level wastes. Synroc requires hot-pressing equipment, while IEB4 precipitates zirconolite from a cooling basaltic melt

  4. Tools and techniques for developing tephra stratigraphies in lake cores: A case study from the basaltic Auckland Volcanic Field, New Zealand

    Science.gov (United States)

    Hopkins, Jenni L.; Millet, Marc-Alban; Timm, Christian; Wilson, Colin J. N.; Leonard, Graham S.; Palin, J. Michael; Neil, Helen

    2015-09-01

    Probabilistic hazard forecasting for a volcanic region relies on understanding and reconstructing the eruptive record (derived potentially from proximal as well as distal volcanoes). Tephrostratigraphy is commonly used as a reconstructive tool by cross-correlating tephra deposits to create a stratigraphic framework that can be used to assess magnitude-frequency relationships for eruptive histories. When applied to widespread rhyolitic deposits, tephra identifications and correlations have been successful; however, the identification and correlation of basaltic tephras are more problematic. Here, using tephras in drill cores from six maars in the Auckland Volcanic Field (AVF), New Zealand, we show how X-ray density scanning coupled with magnetic susceptibility analysis can be used to accurately and reliably identify basaltic glass shard-bearing horizons in lacustrine sediments and which, when combined with the major and trace element signatures of the tephras, can be used to distinguish primary from reworked layers. After reliably identifying primary vs. reworked basaltic horizons within the cores, we detail an improved method for cross-core correlation based on stratigraphy and geochemical fingerprinting. We present major and trace element data for individual glass shards from 57 separate basaltic horizons identified within the cores. Our results suggest that in cases where major element compositions (SiO2, CaO, Al2O3, FeO, MgO) do not provide unambiguous correlations, trace elements (e.g. La, Gd, Yb, Zr, Nb, Nd) and trace element ratios (e.g. [La/Yb]N, [Gd/Yb]N, [Zr/Yb]N) are successful in improving the compositional distinction between the AVF basaltic tephra horizons, thereby allowing an improved eruptive history of the AVF to be reconstructed.

  5. Characterization of elemental release during microbe basalt interactions at T = 28 °C

    Science.gov (United States)

    Wu, Lingling; Jacobson, Andrew D.; Chen, Hsin-Chieh; Hausner, Martina

    2007-05-01

    small amount of apatite (˜1.2%), which occurs as needles within feldspar grains and glass. We therefore conclude that B. fungorum utilized apatite as a P source for biomass synthesis, which stimulated elemental release from coexisting mineral phases via pH lowering. The results of this study suggest that actively metabolizing bacteria have the potential to influence elemental release from basalt in continental settings.

  6. Historical volcanic eruptions in the Canary Islands, tephra composition, and insights into the crystal cargo of basaltic magmas

    Science.gov (United States)

    Longpre, M. A.; Muller, J.; Beaudry, P.; Andronikides, A.; Felpeto, A.

    2017-12-01

    Since the 16th century, at least 13 volcanic eruptions have occurred in the Canary Islands that formed monogenetic cinder cones and lava flow fields: 2 on Lanzarote, 4 on Tenerife, 6 on La Palma, and 1 on the submarine flank of El Hierro. Here we present a comprehensive new dataset of tephra composition for all 13 eruptions, comprising major and trace element data for bulk rocks and matrix glasses, as well as vesicularity and crystallinity measurements. In addition, we compile available volcanological and petrological information for specific eruptions, including estimates of lava flow area and volume. All lapilli samples show a vesicularity of 40-50 vol% and a vesicle-free crystallinity (crystals ≥ 250 µm) of 5-15 vol%. Modal mineralogy varies significantly between samples, typically consisting of olivine ± clinopyroxene ± Fe-Ti oxide ± plagioclase ± amphibole in different proportions. All but 2 tephras have basanite-tephrite bulk rock compositions. Lapilli from vents of the AD 1730-1736 Timanfaya eruption, Lanzarote, largely are basaltic, whereas the AD 1798 Chahorra eruption, Tenerife, produced phonotephrite tephra. These results are in agreement with published bulk lava flow data. Unsurprisingly, glass compositions are more evolved than bulk rocks and MgOglass is weakly positively correlated to MgObulk (MgOglass = 0.30*MgObulk + 2.11, R2 = 0.54). Both bulk rocks and glasses show strikingly similar multi-element diagram patterns, with strong enrichment relative to the bulk-silicate Earth and marked positive Nb and Ta and negative Pb anomalies — typical for ocean island basalts. Glass/bulk rock elemental ratios reveal systematic differences between samples that relate to their mineralogy; for example, Lanzarote tephras that lack significant clinopyroxene and Fe-Ti oxide crystals have higher Scglass/Scbulk and Vglass/Vbulk than Tenerife, La Palma and El Hierro samples that typically contain these minerals. Among all elements, K and P display the greatest

  7. Summary of INEL research on the iron-enriched basalt waste form

    International Nuclear Information System (INIS)

    Reimann, G.A.; Grandy, J.D.; Eddy, T.L.; Anderson, G.L.

    1992-01-01

    This report summarizes the knowledge base on the iron-enriched basalt (IEB) waste form developed at the Idaho National Engineering Laboratory (INEL) during 1979--1982. The results presented discuss the applicability of IEB in converting retrieved transuranic (TRU) waste from INEL's Radioactive Waste Management Complex (RWMC) into a vitreous/ceramic (glassy/rock) stable waste form suitable for permanent disposal in an appropriate repository, such as the Waste Isolation Pilot Plant (WIPP) in New Mexico. Borosilicate glass (BSG), the approved high-level waste form, appears unsuited for this application. Melting the average waste-soil mix from the RWMC produces the IEB composition and attempting to convert IEB to the BSG composition would require additions of substantial B 2 0 3 , Na, and SiO 2 (glass frit). IEB requires processing temperatures of 1400 to 1600 degrees C, depending upon the waste composition. Production of the IEB waste form, using Joule heated melters, has proved difficult in the past because of electrode and refractory corrosion problems associated with the high temperature melts. Higher temperature electric melters (arc and plasma) are available to produce this final waste form. Past research focused on extensive slag property measurements, waste form leachability tests, mechanical, composition, and microstructure evaluations, as well as a host of experiments to improve production of the waste form. Past INEL studies indicated that the IEB glass-ceramic is a material that will accommodate and stabilize a wide range of heterogeneous waste materials, including long lived radionuclides and scrap metals, while maintaining a superior level of chemical and physical performance characteristics. Controlled cooling of the molten IEB and subsequent heat treatment will produce a glass-ceramic waste form with superior leach resistance

  8. Heterotrophic Fe-Oxidizing Bacteria Associated With Basalt Surfaces Supporting Life On Vailulu'u Seamount, American Samoa

    Science.gov (United States)

    Haucke, L.; Templeton, A.; Bailey, B.; Tebo, B.; Staudigel, H.

    2005-12-01

    Fe, the fourth-most abundant element in the Earth's crust, is also one of the most biologically essential ones. The reduced form, Fe(II), is often considered to be biologically limiting as a result of its low solubility and rapid chemical oxidation to Fe(III)(hydr)oxides at circumneutral pH. The alteration of basaltic glass, enriched in Fe(II), however, provides an abundant supply of reduced iron and, thus, has a major influence on local ocean chemistry and Fe bioavailability. Despite the fact that chemical Fe(II) oxidation takes place very rapidly, we demonstrate that alteration processes of freshly formed basaltic glass can be crucially enhanced by microbial activity.Cultivation of bacteria from basalt surfaces collected from two active submarine volcanoes, Loihi (Hawaii) and Vailulu'u (American Samoa) show a large number of heterotrophic bacteria capable of oxidizing Fe(II) and that these bacteria. not only enhance basalt dissolution but also play a major role in precipitating large amounts of thick Fe(hydr)oxides mats on Vailulu'u Seamount, particularly in the vicinity of low temperature hydrothermal vents. These mats contain substantial quantities of organic carbon that may serve as food sources for some of the macrobiological life on Vailulu'u Seamount. This very prominently includes a substantial population of eels that is found in close spatial association with up to 1m thick Fe oxide/microbial mat at Nafanua volcano, a recent volcanic cone that grew from the crater floor of the seamount. Microbial community analysis on different substrates ranging from basalt surfaces to microbial mats were performed on specially designed culturing media for detection and isolation of heterotrophic bacteria capable of Fe(II)-oxidation. Clone libraries from microbial mats originating from an eel dominated area of Vailulu'u crater are being compared to libraries made from eel guts in order to provide information to what extent these mats are being used as a food source in

  9. Icelandic basaltic geothermal field: A natural analog for nuclear waste isolation in basalt

    International Nuclear Information System (INIS)

    Ulmer, G.C.; Grandstaff, D.E.

    1984-01-01

    Analog studies of Icelandic geothermal fields have shown that the design of nuclear waste repositories in basalt can benefit by comparison to the data base already available from the development of these geothermal fields. A high degree of similarity exists between these two systems: their petrology, groundwater geochemistry, mineral solubilities, hydrologic parameters, temperature ranges, water-rock redox equilibria, hydrothermal pH values, and secondary mineralogies all show considerable overlap in the range of values. The experimentally-simulated hydrothermal studies of the basaltic nuclear waste repository rocks have, at this time, produced a data base that receives a strong confirmation from the Icelandic analog. Furthermore, the Icelandic analog should eventually be employed to extrapolate into higher and lower temperatures, into longer time-base chemical comparisons, and into more realistic mineral deposition studies, than have been possible in the laboratory evaluations of the nuclear waste repository designs. This eventual use of the Icelandic analog will require cooperative work with the Icelandic Geological Survey. 46 refs., 4 figs., 2 tabs

  10. Vapor segregation and loss in basaltic melts

    Science.gov (United States)

    Edmonds, M.; Gerlach, T.M.

    2007-01-01

    Measurements of volcanic gases at Pu'u'O??'o??, Kilauea Volcano, Hawai'i, reveal distinct degassing regimes with respect to vapor segregation and loss during effusive activity in 2004-2005. Three styles of vapor loss are distinguished by the chemical character of the emitted volcanic gases, measured by open path Fourier transform infrared spectroscopy: 1 persistent continuous gas emission, 2 gas piston events, and 3 lava spattering. Persistent continuous gas emission is associated with magma ascent and degassing beneath the crater vents, then eruption of the degassed magma from flank vents. Gas piston events are the result of static gas accumulation at depths of 400-900 m beneath Pu'u'O??'o??. A CO2-rich gas slug travels up the conduit at a few meters per second, displacing magma as it expands. Lava spattering occurs due to dynamic bubble coalescence in a column of relatively stagnant magma. The Large gas bubbles are H2O rich and are generated by open-system degassing at depths of gas accumulation and dynamic bubble coalescence are both manifestations of vapor segregation in basaltic melts, but their implications differ. Accumulation and segregation of CO2-rich vapor at depth does not deplete the melt of H2O (required to drive lava fountains near to the surface) and therefore gas piston events can occur interspersed with lava fountaining activity. Lava spattering, however, efficiently strips H2O-rich vapor from magma beneath the crater vents; the magma must then erupt effusively from vents on the flank of the cone. ?? 2007 The Geological Society of America.

  11. Basalt Waste Isolation Project Reclamation Support Project:

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.; Cadoret, N.A.

    1992-06-01

    The Basalt Waste Isolation Project (BWIP) Reclamation Support Project began in the spring of 1988 by categorizing sites distributed during operations of the BWIP into those requiring revegetation and those to be abandoned or transferred to other programs. The Pacific Northwest Laboratory's role in this project was to develop plans for reestablishing native vegetation on the first category of sites, to monitor the implementation of these plans, to evaluate the effectiveness of these efforts, and to identify remediation methods where necessary. The Reclamation Support Project focused on three major areas: geologic hydrologic boreholes, the Exploratory Shaft Facility (ESF), and the Near-Surface Test Facility (NSTF). A number of BWIP reclamation sites seeded between 1989 and 1990 were found to be far below reclamation objectives. These sites were remediated in 1991 using various seedbed treatments designed to rectify problems with water-holding capacity, herbicide activity, surficial crust formation, and nutrient imbalances. Remediation was conducted during November and early December 1991. Sites were examined on a monthly basis thereafter to evaluate plant growth responses to these treatments. At all remediation sites early plant growth responses to these treatments. At all remediation sites, early plant growth far exceeded any previously obtained using other methods and seedbed treatments. Seeded plants did best where amendments consisted of soil-plus-compost or fertilizer-only. Vegetation growth on Gable Mountain was less than that found on other areas nearby, but this difference is attributed primarily to the site's altitude and north-facing orientation.

  12. Combined Li-He isotopes in Iceland and Jan Mayen basalts and constraints on the nature of the North Atlantic mantle

    Science.gov (United States)

    Magna, T.; Wiechert, U.; Stuart, F. M.; Halliday, A. N.; Harrison, D.

    2011-02-01

    Lithium (Li) isotopes are thought to provide a powerful proxy for the recycling of crustal material, affected by low temperature alteration, through the mantle. We present Li isotope compositions for basaltic volcanic rocks from Hengill, Iceland, and Jan Mayen in order to examine possible links between ocean island volcanism and recycled oceanic crust and to address recent suggestions that mantle 3He/ 4He is also related to recycling of ancient slabs. Basaltic glasses spanning a range of chemical enrichment from the Hengill fissure system define an inverse correlation between δ 7Li (3.8-6.9‰) and 3He/ 4He (12-20 RA). The high- 3He/ 4He basalts have low δ 18O as well as excess Eu and high Nb/U, but carry no Li isotope evidence of being the product of recycling of altered slab or wedge material. In fact, there is no clear correlation between Li or He isotopes on the one hand and any of the other fingerprints of recycled slab components. The low- 3He/ 4He samples do have elevated Nb/U, Sr/Nd, positive Eu anomalies and high δ 7Li (˜6.9‰), providing evidence of a cumulate-enriched source that could be part of an ancient altered ocean floor slab. Basalts from Jan Mayen are characterized by large degrees of enrichment in incompatible trace elements typical of EM-like basalts but have homogeneous δ 7Li typical of depleted mantle (3.9-4.7‰) providing evidence for a third mantle source in the North Atlantic. It appears that oceanic basalts can display a wide range in isotope and trace element compositions associated with recycled components whilst exhibiting no sign of modern surface-altered slab or wedge material from the Li isotope composition.

  13. Conduit margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand.

    Science.gov (United States)

    Schauroth, Jenny; Wadsworth, Fabian B; Kennedy, Ben; von Aulock, Felix W; Lavallée, Yan; Damby, David E; Vasseur, Jérémie; Scheu, Bettina; Dingwell, Donald B

    During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a conduit. Here, we have analysed textures preserved in the walls of a pyroclastic feeder dyke of the AD 1886 Tarawera basaltic Plinian fissure eruption. The samples examined consist of basaltic ash and scoria plastered onto a conduit wall of a coherent rhyolite dome and a welded rhyolitic dome breccia. We examine the textural evidence for the response of the wall material, built of ∼75 vol.% glass and ∼25 vol.% crystals (pore-free equivalent), to mass movement in the adjacent conduit. In the rhyolitic wall material, we quantify the orientation and aspect ratio of biotite crystals as strain markers of simple shear deformation, and interpret juxtaposed regions of vesiculation and vesicle collapse as evidence of conduit wall heating. Systematic changes occur close to the margin: (1) porosity is highly variable, with areas locally vesiculated or densified, (2) biotite crystals are oriented with their long axis parallel to the margin, (3) the biotites have greater aspect ratios close to the margin and (4) the biotite crystals are fractured. We interpret the biotite phenocryst deformation to result from crystal fracture, rotation and cleavage-parallel bookcase translation. These textural observations are inferred to indicate mechanical coupling between the hot gas-ash jet and the conduit wall and reheating of wall rock rhyolite. We couple these observations with a simple 1D conductive heating model to show what minimum temperature the conduit wall needs to reach in order to achieve a temperature above the glass transition throughout the texturally-defined deformed zone. We propose that conduit wall heating and resulting deformation influences conduit margin outgassing and may enhance the intensity of such large basaltic eruptions.

  14. Preliminary Hydrogeologic Characterization Results from the Wallula Basalt Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    B.P. McGrail; E. C. Sullivan; F. A. Spane; D. H. Bacon; G. Hund; P. D. Thorne; C. J. Thompson; S. P. Reidel; F. S. Colwell

    2009-12-01

    The DOE's Big Sky Regional Carbon Sequestration Partnership has completed drilling the first continental flood basalt sequestration pilot borehole to a total depth (TD) of 4,110 feet on the Boise White Paper Mill property at Wallula, Washington. Site suitability was assessed prior to drilling by the 2007-2008 acquisition, processing and analysis of a four-mile, five-line three component seismic swath, which was processed as a single data-dense line. Analysis of the seismic survey data indicated a composite basalt formation thickness of {approx}8,000 feet and absence of major geologic structures (i.e., faults) along the line imaged by the seismic swath. Drilling of Wallula pilot borehole was initiated on January 13, 2009 and reached TD on April 6, 2009. Based on characterization results obtained during drilling, three basalt breccia zones were identified between the depth interval of 2,716 and 2,910 feet, as being suitable injection reservoir for a subsequent CO2 injection pilot study. The targeted injection reservoir lies stratigraphically below the massive Umtanum Member of the Grande Ronde Basalt, whose flow-interior section possesses regionally recognized low-permeability characteristics. The identified composite injection zone reservoir provides a unique and attractive opportunity to scientifically study the reservoir behavior of three inter-connected reservoir intervals below primary and secondary caprock confining zones. Drill cuttings, wireline geophysical logs, and 31one-inch diameter rotary sidewall cores provided geologic data for characterization of rock properties. XRF analyses of selected rock samples provided geochemical characterizations of the rocks and stratigraphic control for the basalt flows encountered by the Wallula pilot borehole. Based on the geochemical results, the pilot borehole was terminated in the Wapshilla Ridge 1 flow of the Grande Ronde Basalt Formation. Detailed hydrologic test characterizations of 12 basalt interflow

  15. Recycling of crystal mush-derived melts and short magma residence times revealed by U-series disequilibria at Stromboli volcano

    Science.gov (United States)

    Bragagni, Alessandro; Avanzinelli, Riccardo; Freymuth, Heye; Francalanci, Lorella

    2014-10-01

    The presence of crystal mushes in the feeding system of active volcanoes is generally revealed by antecrysts, representing the crystalline portion of old magmas recycled in the juvenile material, but very little is known about the fate of interstitial liquid hosted within the crystal-rich mush (i.e. antemelt). U-series disequilibria measured in magmas erupted in the past 18 years at Stromboli volcano provide the first geochemical evidence of the involvement of antemelt and help constraining the timescales of the processes occurring in the plumbing system of the volcano. Despite almost constant major and trace element composition, significant variations in isotope ratios are observed. (230Th/232Th) decreases with time, whilst (238U/232Th), (226Ra/230Th) and 87Sr/86Sr are different in the two types of magma erupted. Magma with low phenocryst content (lp) is erupted as pumices during paroxysm and is thought to belong to a deep reservoir. Highly porphyritic magma (hp) is erupted during the normal ;Strombolian; activity as scoria and during the effusive events as lavas, and it is considered to derive from the former one within a shallow reservoir through degassing-driven crystallisation, mixing and incorporation of antecrysts. The distinct (238U/232Th) of lp and hp magma requires the involvement of a component with high 87Sr/86Sr and (238U/232Th) deriving from older magmas erupted earlier in the volcano history (up to 2.5 ka). The incompatibility of U and Th in major mineral phases limits the possible effect of antecrysts, hence requiring the involvement of a U- and Th-rich antemelt. The decrease of 226Ra-excess from lp to hp magmas provides further and independent evidence for the involvement of a few thousands years old antemelt. The variation with time of (230Th/232Th) within lp and hp magmas is exploited to constrain the residence time of magmas in the deep and shallow reservoir of the volcano to < 55 yrs (inferred reservoir volume < 0.5 km3) and 2-10 yrs (inferred

  16. Dynamics of the shallow plumbing system investigated from borehole strainmeters and cameras during the 15 March, 2007 Vulcanian paroxysm at Stromboli volcano

    Science.gov (United States)

    Bonaccorso, Alessandro; Calvari, Sonia; Linde, Alan; Sacks, Selwyn; Boschi, Enzo

    2012-12-01

    The 15 March, 2007 Vulcanian paroxysm at Stromboli volcano was recorded by several instruments that allowed description of the eruptive sequence and unraveling the processes in the upper feeding system. Among the devices installed on the island, two borehole strainmeters recorded unique signals not fully explored before. Here we present an analysis of these signals together with the time-lapse images from a monitoring system comprising both infrared and visual cameras. The two strainmeter signals display an initial phase of pressure growth in the feeding system lasting ˜2 min. This is followed by 25 s of low-amplitude oscillations of the two signals, that we interpret as a strong step-like overpressure building up in the uppermost conduit by the gas-rich magma accumulating below a thick pile of rock produced by crater rim collapses. This overpressure caused shaking of the ground, and triggered a number of small landslides of the inner crater rim recorded by the monitoring cameras. When the plug obstructing the crater was removed by the initial Vulcanian blast, the two strainmeter signals showed opposite sign, compatible with a depressurizing source at ˜1.5 km depth, at the junction between the intermediate and shallow feeding system inferred by previous studies. The sudden depressurization accompanying the Vulcanian blast caused an oscillation of the source composed by three cycles of about 20 s each with a decreasing amplitude, as well recorded by the strainmeters. The visible effect of this behavior was the initial Vulcanian blast and a 2-3 km high eruptive column followed by two lava fountainings displaying decreasing intensity and height. To our knowledge, this is the first time that such a behavior was observed on an open conduit volcano.

  17. Game of thrown bombs in 3D: using high speed cameras and photogrammetry techniques to reconstruct bomb trajectories at Stromboli (Italy)

    Science.gov (United States)

    Gaudin, D.; Taddeucci, J.; Scarlato, P.; Del Bello, E.; Houghton, B. F.; Orr, T. R.; Andronico, D.; Kueppers, U.

    2015-12-01

    Large juvenile bombs and lithic clasts, produced and ejected during explosive volcanic eruptions, follow ballistic trajectories. Of particular interest are: 1) the determination of ejection velocity and launch angle, which give insights into shallow conduit conditions and geometry; 2) particle trajectories, with an eye on trajectory evolution caused by collisions between bombs, as well as the interaction between bombs and ash/gas plumes; and 3) the computation of the final emplacement of bomb-sized clasts, which is important for hazard assessment and risk management. Ground-based imagery from a single camera only allows the reconstruction of bomb trajectories in a plan perpendicular to the line of sight, which may lead to underestimation of bomb velocities and does not allow the directionality of the ejections to be studied. To overcome this limitation, we adapted photogrammetry techniques to reconstruct 3D bomb trajectories from two or three synchronized high-speed video cameras. In particular, we modified existing algorithms to consider the errors that may arise from the very high velocity of the particles and the impossibility of measuring tie points close to the scene. Our method was tested during two field campaigns at Stromboli. In 2014, two high-speed cameras with a 500 Hz frame rate and a ~2 cm resolution were set up ~350m from the crater, 10° apart and synchronized. The experiment was repeated with similar parameters in 2015, but using three high-speed cameras in order to significantly reduce uncertainties and allow their estimation. Trajectory analyses for tens of bombs at various times allowed for the identification of shifts in the mean directivity and dispersal angle of the jets during the explosions. These time evolutions are also visible on the permanent video-camera monitoring system, demonstrating the applicability of our method to all kinds of explosive volcanoes.

  18. Thermal history of Hawaiian pāhoehoe lava crusts at the glass transition: implications for flow rheology and emplacement

    Science.gov (United States)

    Gottsmann, Joachim; Harris, Andrew J. L.; Dingwell, Donald B.

    2004-12-01

    We have investigated the thermal history of glassy pāhoehoe crusts across their glass transition. Ten different samples obtained between 1993 and 2003 from the active flow field of the Pu'u 'O'o-Kupaianaha eruption on Hawaii (USA) have been analysed using relaxation geospeedometry. This method employs differential scanning calorimetry to quantify the enthalpic relaxation of the glass to monitor the natural time-temperature (t-T) path followed by the melt during cooling across its glass transition. Cooling rates across the glass transition interval (at 1000- 900 K) have been found to vary between 8 and 140 K/min. The associated glass transition temperatures are up to 400 K, lower than previously anticipated by others. Melt viscosities at the glass transition for these crusts range from 10 9.4 to 10 10.7 Pa s. We have compared the t-T paths quantified via relaxation geospeedometry with those obtained from direct measurements on the active flow field. The calorimetrically determined cooling rates are consistent with either simple cooling from eruption temperatures to temperatures below the glass transition or more complex cooling paths, including periods of reheating and short-term annealing within the glass transition interval. By quantifying the relaxation times associated with these contrasting cooling histories, we show that secondary vesiculation of pāhoehoe flow crusts may be favoured by complex, nonlinear t-T paths within the glass transition. These constraints also allow us to evaluate the time scales associated with the crystallisation and inflation of flow lobes at the glass transition for different pāhoehoe lava flow types. Our results provide important quantifications of rheological parameters at the lower temperature range of viscoelastic deformation in basaltic lava flows. As such, the results may be helpful in refining models for the generation of continental flood basalt flows, as well as models of basaltic lava flow propagation for hazard

  19. Corrosion phase formation on container alloys in basalt repository environments

    International Nuclear Information System (INIS)

    Johnston, R.G.; Anantatmula, R.P.; Lutton, J.M.; Rivera, C.L.

    1986-01-01

    The Basalt Waste Isolation Project is evaluating the suitability of basalt in southeastern Washington State as a possible location for a nuclear waste repository. The performance of the waste package, which includes the waste form, container, and surrounding packing material, will be affected by the stability of container alloys in the repository environment. Primary corrosion phases and altered packing material containing metals leached from the container may also influence subsequent reactions between the waste form and repository environment. Copper- and iron-based alloys were tested at 50 0 to 300 0 C in an air/steam environment and in pressure vessels in ground-water-saturated basalt-bentonite packing material. Reaction phases formed on the alloys were identified and corrosion rates were measured. Changes in adhering packing material were also evaluated. The observed reactions and their possible effects on container alloy durability in the repository are discussed

  20. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  1. Age of the youngest Palaeogene flood basalts in East Greenland

    DEFF Research Database (Denmark)

    Heilmann-Clausen, C.; Piasecki, Stefan; Abrahamsen, Niels

    2008-01-01

    results, this constrains the termination of the East Greenland Paleogene Igneous Province to the Early-Middle Eocene transition (nannoplankton chronozones NP13-NP14/earliest NP15). This is 6-8 Ma younger than according to previous biostratigraphic age assignments. The new data show that flood basalt......Intra-basaltic sediments 50 m below the top of the Paleogene lava succession at Kap Dalton, East Greenland, contain dinoflagellate cysts of late Ypresian-earliest Lutetian age, while sediments immediately above the lavas contain an assemblage of early Lutetian age. Combined with paleomagnetic...

  2. Quaternary basaltic volcanism in the Payenia volcanic province, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina

    in basalts from all the studied volcanic fields in Payenia is signs of lower crustal contamination indicating assimilation of, in some cases, large amounts of trace element depleted, mafic, plagioclase-bearing rocks. The northern Payenia is dominated by backarc basalts erupted between late Pliocene to late...... are isotopically similar to the Andean Southern Volcanic Zone arc rocks and their mantle source possibly resembled the source of South Atlantic N-MORB prior to addition of fluids and melts from the subduction channel. However, it must have been more enriched than the estimates of depleted upper mantle from...

  3. Flood basalt volcanism on the Moon and Mars

    International Nuclear Information System (INIS)

    Benes, K.

    1979-01-01

    Comparative studies of the surfaces of the terrestrial planets reveal that processes of flood basalt volcanism were common to all of them, irrespective of their stages of evolution either primitive, intermediate or progressive. On the Moon manifestations of flood basalt volcanism have been recognized in basins (maria); on the planet Mars both in basins (planitiae) and in higher topographic (continental) levels. The mare-epoch of the less developed planets led to significant changes in their relief and in the crustal structure. Examples of volcanic flows from the lunar and martian surface are introduced. Some crustal uplifts on Mars can be interpreted in terms of Van Bemmelen's undations. (Auth.)

  4. Halogen degassing during ascent and eruption of water-poor basaltic magma

    Science.gov (United States)

    Edmonds, M.; Gerlach, T.M.; Herd, Richard A.

    2009-01-01

    A study of volcanic gas composition and matrix glass volatile concentrations has allowed a model for halogen degassing to be formulated for K??lauea Volcano, Hawai'i. Volcanic gases emitted during 2004-2005 were characterised by a molar SO2/HCl of 10-64, with a mean of 33; and a molar HF/HCl of 0-5, with a mean of 1.0 (from approximately 2500 measurements). The HF/HCl ratio was more variable than the SO2/HCl ratio, and the two correlate weakly. Variations in ratio took place over rapid timescales (seconds). Matrix glasses of Pele's tears erupted in 2006 have a mean S, Cl and F content of 67, 85 and 173??ppm respectively, but are associated with a large range in S/F. A model is developed that describes the open system degassing of halogens from parental magmas, using the glass data from this study, previously published results and parameterisation of sulphur degassing from previous work. The results illustrate that halogen degassing takes place at pressures of gas data and other observations of volcanic activity well and is consistent with other studies of halogen degassing from basaltic magmas. The model suggests that variation in volcanic gas halogen ratios is caused by exsolution and gas-melt separation at low pressures in the conduit. There is no evidence that either diffusive fractionation or near-vent chemical reactions involving halogens is important in the system, although these processes cannot be ruled out. The fluxes of HCl and HF from K??lauea during 2004-5 were ~ 25 and 12??t/d respectively. ?? 2008 Elsevier B.V.

  5. Geochemical models of melting and magma storage conditions for basalt lava from Santorini Volcano, Greece

    Science.gov (United States)

    Baziotis, Ioannis; Kimura, Jun-Ichi; Pantazidis, Avgoustinos; Klemme, Stephan; Berndt, Jasper; Asimow, Paul

    2017-04-01

    Santorini volcano sits ˜150 km above the Wadati-Benioff zone of the Aegean arc, where the African plate subducts northward beneath the Eurasian continent (Papazachos et al. 2000). Santorini volcano has a long history: activity started ca. 650 ka (mainly rhyolites and rhyodacites), with active pulses following ca. 550 ka (basalt to rhyodacite) and ca. 360 ka (large explosive eruptions of andesite to rhyodacite and minor basalt), culminating in the caldera-forming Bronze-age Minoan event (Druitt et al. 1999). As in many arc volcanoes, scenarios of fractional crystallization with or without mixing between felsic and mafic magmas have been proposed to explain the compositions, textures, and eruptive styles of Santorini products (e.g., Huijsmans & Barton 1989; Montazavi & Sparks 2004; Andújar et al. 2015). Here we focus on a basalt lava from the southern part of Santorini volcano (Balos cove, 36˚ 21.7'N, 25˚ 23.8'E), one of the few basaltic localities in the Aegean arc. The goals are to infer constraints on the magma chamber conditions which lead to mafic eruption at Santorini Volcano and to evaluate the slab and mantle wedge conditions via geochemical and petrological mass balance modelling. We collected and characterised 20 samples for texture (SEM), mineral chemistry (FE-EPMA) and whole-rock chemistry (XRF). The basalts contain phenocrystic olivine (Ol) and clinopyroxene (Cpx) (<600 μm diameter) in a fine groundmass (<100 μm diameter) of Ol, Cpx, plagioclase (Pl) and magnetite (Mt) with minor glass and rare xenocrystic quartz. Santorini basalts exhibit a pilotaxitic to trachytic texture defined by randomly to flow-oriented tabular Pl, respectively. The predominant minerals are calcic Pl (core An78-85 and rim An60-76; 45-50 vol.%), Cpx (En36-48Wo41-44Fs11-21; 10-15 vol.%) and Ol (Fo74-88; 10-12 vol.%). Idiomorphic to subidiomorphic Mt (<10μm diameter) with variable TiO2 contents (1.9-16.5 wt%) is a minor constituent (˜1-2 vol.%) in the less mafic samples

  6. Orientation-dependent electromagnetic properties of basalt fibre/nickel core–shell heterostructures

    International Nuclear Information System (INIS)

    Yu-Qing, Kang; Mao-Sheng, Cao; Xiao-Yong, Fang; Jie, Yuan

    2010-01-01

    The influence of orientation on electromagnetic properties of basalt fibre/nickel core–shell heterostructures prepared by a simple electroless plating method is investigated. For comparison, the same investigation is also performed on naked basalt fibres. For electromagnetic measurement, the directions of basalt fibre/nickel and naked basalt fibres are parallel, random and perpendicular to the direction of external electric field, termed E || sample, random sample and E p erpendicular sample, respectively. Electromagnetic anisotropy can be clearly observed in the basalt fibre/nickel core–shell heterostructures, while electromagnetic properties of naked basalt fibres are unrelated to the orientation. The E p erpendicular basalt fibre/nickel shows the highest dielectric loss but the lowest magnetic loss, and E || basalt fibre/nickel exhibits the highest magnetic loss but the lowest dielectric loss. The dielectric loss of E p erpendicular basalt fibre/nickel is several times as large as that of E || basalt fibre/nickel, which could be attributed to the increase of polarization relaxation time as a consequence of the nanosize-confinement effect. The magnetic loss of E || basalt fibre/nickel is even one order of magnitude higher than that of E p erpendicular basalt fibre/nickel, which originates mainly from the natural magnetic resonance of basalt fibre/nickel core–shell heterostructures. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. Genesis of amethyst geodes in basaltic rocks of the Serra Geral Formation (Ametista do Sul, Rio Grande do Sul, Brazil): a fluid inclusion, REE, oxygen, carbon, and Sr isotope study on basalt, quartz, and calcite

    Science.gov (United States)

    Gilg, H. Albert; Morteani, Giulio; Kostitsyn, Yuri; Preinfalk, Christine; Gatter, Istvan; Strieder, Adelir J.

    2003-12-01

    In the Ametista do Sul area, Rio Grande do Sul, Brazil, amethyst-bearing geodes are hosted by a ~40- to 50-m-thick subhorizontal high-Ti basaltic lava flow of the Lower Cretaceous Paraná Continental Flood Basalt Province. The typically spherical cap-shaped, sometimes vertically elongated geodes display an outer rim of celadonite followed inwards by agate and colorless and finally amethystine quartz. Calcite formed throughout the whole crystallization sequence, but most commonly as very late euhedral crystals, sometimes with gypsum, in the central cavity. Fluid inclusions in colorless quartz and amethyst are predominantly monophase and contain an aqueous liquid. Two-phase liquid-vapor inclusions are rare. Some with a consistent degree of fill homogenize into the liquid between 95 and 98 °C. Ice-melting temperatures in the absence of a vapor phase between -4 and +4 °C indicate low salinities. Chondrite-normalized REE patterns of calcites are highly variable and show generally no systematic correlation with the paragenetic sequence. The oxygen isotope composition of calcites is very homogeneous (δ18OVSMOW=24.9±1.1‰, n=34) indicating crystallization temperatures of less than 100 °C. Carbon isotope values of calcites show a considerable variation ranging from -18.7 to -2.9‰ (VPDB). The 87Sr/86Sr ratio of calcites varies between 0.706 and 0.708 and is more radiogenic than that of the host basalt (~0.705). The most likely source of silica, calcium, carbon, and minor elements in the infill of the geodes is the highly reactive interstitial glass of the host basalts leached by gas-poor aqueous solutions of meteoric origin ascending from the locally artesian Botucatú aquifer system in the footwall of the volcanic sequence. The genesis of amethyst geodes in basalts at Ametista do Sul, Brazil, is thus considered as a two-stage process with an early magmatic protogeode formation and a late, low temperature infill of the cavity.

  8. Magmatic evolution of the fresh basalts from the Ridge axis near Egaria Fracture Zone, Central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mudholkar, A.V.

    the basalts under study. These gradual changes in the olivines and plagioclase point to a simple evolution of the basaltic magma by differentiating mineral phases from the parental basalt The resorption features observed in high forsteritic olivines (~ 89...

  9. Glass and nuclear wastes

    International Nuclear Information System (INIS)

    Sombret, C.

    1982-10-01

    Glass shows interesting technical and economical properties for long term storage of solidified radioactive wastes by vitrification or embedding. Glass composition, vitrification processes, stability under irradiation, thermal stability and aqueous corrosion are studied [fr

  10. Microstructuring of glasses

    CERN Document Server

    Hülsenberg, Dagmar; Bismarck, Alexander

    2008-01-01

    As microstructured glass becomes increasingly important for microsystems technology, the main application fields include micro-fluidic systems, micro-analysis systems, sensors, micro-actuators and implants. And, because glass has quite distinct properties from silicon, PMMA and metals, applications exist where only glass devices meet the requirements. The main advantages of glass derive from its amorphous nature, the precondition for its - theoretically - direction-independent geometric structurability. Microstructuring of Glasses deals with the amorphous state, various glass compositions and their properties, the interactions between glasses and the electromagnetic waves used to modify it. Also treated in detail are methods for influencing the geometrical microstructure of glasses by mechanical, chemical, thermal, optical, and electrical treatment, and the methods and equipment required to produce actual microdevices.

  11. Characterization of fibers as rockwool for insulation obtained from canary islands basalts

    Directory of Open Access Journals (Sweden)

    Cáceres, J. M.

    1996-06-01

    Full Text Available Glass fibers in the shape of wool were obtained at laboratory scale from three samples of basaltic rocks from the Tenerife Island. The rockwool is widely used as thermal and acoustical insulation. The ability of these rocks to be fiberized was studied by means of the viscosity curves and can be quite improved by adding calcium and magnesium. The experimental fibers obtained from the rocks directly or mixed with either CaCO3 or CaMg(CO32 ye characterized in terms of chemical composition, microstructure and thermal and mechanical properties. These properties were compared with the ones determined for four commercial samples of rockcwool, founding that they are very close. This gives good prospects to these fibers from Canarian basalts as insulation material.

    Se ha obtenido fibra de vidrio en forma de lana, a escala de laboratorio, a partir de tres muestras de rocas basálticas de la Isla de Tenerife. La lana de roca se emplea extensamente como aislamiento térmico y acústico. La aptitud de estas rocas para su fibrado, estudiada mediante las curvas de viscosidad, mejora considerablemente con la adición de calcio y magnesio. Las fibras experimentales, obtenidas tanto a partir de las rocas directamente, como mezcladas en diferentes proporciones con CaCO3 o CaMg(CO32, se han caracterizado en lo referente a la composición química, la microestructura y propiedades térmicas y mecánicas. Así mismo, se han comparado estas propiedades con las determinadas para cuatro muestras comerciales de lana de roca, permitiendo comprobar que son bastante semejantes, lo que hace prever unas buenas cualidades para estas fibras de basaltos canarios en aplicaciones de aislamiento térmico y acústico.

  12. Experimental study of the Mg and Sr isotopic evolution of seawater interacting with basalt between 150 and 300 ° C.

    Science.gov (United States)

    Voigt, Martin; Pearce, Christopher R.; Oelkers, Eric H.

    2016-04-01

    The chemical exchange of material between seawater and the oceanic crust plays a major role in marine geochemical cycles [1]. Isotopic signatures provide an important means of tracing elemental transfer in hydrothermal environments, yet only a limited amount of experimental data on the extent of isotopic fractionation under these conditions is currently available. This study consequently investigated the extent of δ26/24Mg and 87Sr/86Sr isotopic variation during a seawater-basalt interaction experiments at 150, 250 and 290 ° C. A suite of closed system experiments were run for several months at each temperature under saturated water pressure, using either crystalline or glassy basalt as the starting material and a water/rock ratio of 10 or 25. Our results demonstrate that the dissolution of basaltic material in hydrothermal environments occurs at the same time as the precipitation of alteration minerals (mainly smectite and anhydrite), which is consistent with results from similar studies in the past (e.g. [2]). As expected, the rate of reaction using crystalline basalt was slower than with basaltic glass, and both sample types reacted faster at higher temperatures. The 87Sr/86Sr composition of the experimental fluids decreased from the initial seawater value (0.70916) towards the lower basaltic signature during the experiments (0.70317), demonstrating the progressive release of Sr during basalt dissolution. Magnesium was steadily removed from the fluid via the precipitation of clay minerals, with the residual fluids having progressively lighter δ26/24Mg compositions. The mean Mg isotope fractionation factor (αsolid-solution) observed at 250 oC was 1.0005±0.0002, supporting low-temperature evidence that clay minerals preferentially incorporate isotopically heavy magnesium [3]. These experiments provide quantitative information on the extent of Mg isotopic fractionation between fluids and secondary silicate minerals in hydrothermal systems, and demonstrate the

  13. Measurement of optical glasses

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1978-11-01

    The possibilities of measurement of the optical glasses parameters needed in building optical devices especially in lasers devices are presented. In the first chapter the general features of the main optical glasses as well as the modalities of obtaining them are given. Chapter two defines the optical glass parameters, and the third chapter describes the measuring methods of the optical glass parameters. Finally, the conclusions which point out the utilization of this paper are presented. (author)

  14. Preliminary feasibility study on storage of radioactive wastes in Columbia River basalts. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    ,

    1976-11-01

    Volume II comprises four appendices: analytical data and sample locations for basalt flow type localities; Analytical data and sample locations for measured field sections in Yakima basalts; core hole lithology and analytical data; and geophysical logs. (LK)

  15. Detection of sub-basaltic sediments by a multi-parametric joint ...

    Indian Academy of Sciences (India)

    ; modelling; structure of the earth. Abstract. In many parts of the world sedimentary horizons with potential for hydrocarbon are located below flood basalt provinces.However,the presence of high velocity basaltic overburden makes delineation ...

  16. Technique for Machining Glass

    Science.gov (United States)

    Rice, S. H.

    1982-01-01

    Process for machining glass with conventional carbide tools requires a small quantity of a lubricant for aluminum applied to area of glass to be machined. A carbide tool is then placed against workpiece with light pressure. Tool is raised periodically to clear work of glass dust and particles. Additional lubricant is applied as it is displaced.

  17. Estimates of mantle thorium/uranium ratios from Th, U and Pb isotope abundances in basaltic melts

    International Nuclear Information System (INIS)

    O'Nions, R.K.; McKenzie, D.

    1993-01-01

    The relationship between the abundances of Th, U and Pb isotopes in basalt melts and the [Th/U] ratio of their source is assessed. A simple melting model is used to show that whereas the activity ratio ( 230 Th/ 232 Th) in the initial melt before extraction is equal to the bulk source ratio, that in the extracted melt may be higher. The difference depends upon the rate of melting relative to the half-life of 230 Th (73 ka). Only when the rate is fast compared to this half life will ( 230 Th/ 232 Th) in the extracted melt provide a correct estimate of [ 232 Th/ 238 U] in the source and therefore of its [Th/U] ratio. This is normally not the case for MORB, and a better estimate of source [Th/U] ratio is derived from [ 232 Th/ 238 U] ratio in the basalt, which does not depend upon the rate of melting. Available data for MORB glasses give a best estimate for their source [Th/U] = 2.58+ 0.06. This value is less than both that of the bulk Earth of 3.9±0.1, and of the source of plume basalts from Iceland and Hawaii, which are 3.3 and 3.2 respectively. These estimates contrast with the [ 232 Th/ 238 U] ratio required to produce the radiogenic { 208 Pb/ 206 Pb} atomic ratio of MORB over 4.55 Ga. This averages 3.8 and is little different from the average derived from Pb-isotopes in plume basalts. These observations are most easily reconciled if Th, U and Pb are efficiently stripped from the mantle by melting and have a residence time there of ≤ 1 Ga. The [Th/U] ratio of 2.6 for the upper mantle requires melt fractions of ≤ 1% to be involved in transferrring U and Th from this region into the continents. Such melt fractions are present in subduction zones and in the source regions of continental alkali basalts. (author)

  18. Late Devonian and Triassic basalts from the southern continental ...

    Indian Academy of Sciences (India)

    In Late Devonian and Early-to-Late Triassic times, the southern continental margin of the Eastern. European Platform was the site of a basaltic volcanism in the Donbas and Fore-Caucasus areas respectively. Both volcanic piles rest unconformably upon Paleoproterozoic and Late Paleozoic units respectively, and emplaced ...

  19. Mineral chemistry of Pangidi basalt flows from Andhra Pradesh

    Indian Academy of Sciences (India)

    The equilibration temperatures of clinopyroxene (1110–1190°C) and titaniferous magnetite and ilmenite coexisting mineral phases (1063–1103°C) are almost similar in lower basalt flow and it is higher for clinopyroxene (900–1110°C) when compared to titaniferous magnetite and ilmenite coexisting mineral phases ...

  20. Automated identification of basalt spectra in Clementine lunar data

    Science.gov (United States)

    Antonenko, I.; Osinski, G. R.

    2011-06-01

    The identification of fresh basalt spectra plays an important role in lunar stratigraphic studies; however, the process can be time consuming and labor intensive. Thus motivated, we developed an empirically derived algorithm for the automated identification of fresh basalt spectra from Clememtine UVVIS data. This algorithm has the following four parameters and limits: BC Ratio=3(R950-R900)/(R900-R750)0.003 and 0.1, where R750 represents the unnormalized reflectance of the 750 nm Clementine band, and so on. Algorithm results were found to be accurate to within an error of 4.5% with respect to visual classification, though olivine spectra may be under-represented. Overall, fresh basalts identified by the algorithm are consistent with expectations and previous work in the Mare Humorum area, though accuracy in other areas has not yet been tested. Great potential exists in using this algorithm for identifying craters that have excavated basalts, estimating the thickness of mare and cryptomare deposits, and other applications.

  1. Assesment of Alkali Resistance of Basalt Used as Concrete Aggregates

    Directory of Open Access Journals (Sweden)

    al-Swaidani Aref M.

    2015-11-01

    Full Text Available The objective of this paper is to report a part of an ongoing research on the influence of using crushed basalt as aggregates on one of durability-related properties of concrete (i.e. alkali-silica reaction which is the most common form of Alkali-Aggregate Reaction. Alkali resistance has been assessed through several methods specified in the American Standards. Results of petrographic examination, chemical test (ASTM C289 and accelerated mortar bar test (ASTM C1260 have particularly been reported. In addition, the weight change and compressive strength of 28 days cured concrete containing basaltic aggregates were also reported after 90 days of exposure to 10% NaOH solution. Dolomite aggregate were used in the latter test for comparison. The experimental results revealed that basaltic rocks quarried from As-Swaida’a region were suitable for production of aggregates for concrete. According to the test results, the studied basalt aggregates can be classified as innocuous with regard to alkali-silica reaction. Further, the 10% sodium hydroxide attack did not affect the compressive strength of concrete.

  2. Nature and composition of interbedded marine basaltic pumice in ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 2. Nature and composition of interbedded marine basaltic pumice in the ~52–50 Ma Vastan lignite sequence, western India: Implication for Early Eocene MORB volcanism offshore Arabian Sea. Sarajit Sensarma Hukam Singh R S Rana Debajyoti Paul ...

  3. Petrography and petrogenesis of some Indian basaltic achondrites ...

    Indian Academy of Sciences (India)

    Notable characteristics observed in Lohawat howardite include crystallization of orthoenstatite first at a high-temperature followed by ferrosilite, pigeonite ... whereas the Johnstown diogenite crystallized from a slow cooling of a Ca-poor basaltic melt derived from cumulates formed from the magma ocean, similar to the origin ...

  4. Petrology of spinel lherzolite xenoliths in alkali basalts from Liri ...

    African Journals Online (AJOL)

    orthopyroxène (En89-91), de clinopyroxène (6,5 % d'Al2O3) et du spinelle riche Al sont présents dans les basaltes alcalins de Liri,. Sud du plateau Kapsiki, extrême nord de la "Ligne chaude du Cameroun". Les données pétrographiques.

  5. Primitive off-rift basalts from Iceland and Jan Mayen

    DEFF Research Database (Denmark)

    Debaille, Vinciane; Trønnes, Reidar G.; Brandon, Alan D.

    2009-01-01

    New measurements of Os, He, Sr and Nd isotopes, along with major and trace elements, are presented for basalts from the three volcanic flank zones in Iceland and from Jan Mayen Island. The 187Os/188Os ratios in lavas with <30 ppt Os (n = 4) are elevated compared to ratios in coexisting olivine an...

  6. Basalt Waste Isolation Project. Annual report, fiscal year 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    This project is aimed at examining the feasibility and providing the technology to design and construct a radwaste repository in basalt formations beneath and within the Hanford Site. The project is divided into seven areas: systems integration, geosciences, hydrologic studies, engineered barriers, near-surface test facility, engineering testing, and repository engineering. This annual report summarizes key investigations in these seven areas. (DLC)

  7. Basalt Waste Isolation Project. Annual report, fiscal year 1979

    International Nuclear Information System (INIS)

    1979-11-01

    This project is aimed at examining the feasibility and providing the technology to design and construct a radwaste repository in basalt formations beneath and within the Hanford Site. The project is divided into seven areas: systems integration, geosciences, hydrologic studies, engineered barriers, near-surface test facility, engineering testing, and repository engineering. This annual report summarizes key investigations in these seven areas

  8. Nature and composition of interbedded marine basaltic pumice in the

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 2. Nature and composition of interbedded marine basaltic pumice in the ~52–50 Ma Vastan lignite sequence, western India: Implication for Early Eocene MORB volcanism offshore Arabian Sea. Sarajit Sensarma Hukam Singh R S Rana Debajyoti Paul ...

  9. Late Devonian and Triassic basalts from the southern continental ...

    Indian Academy of Sciences (India)

    In Late Devonian and Early-to-Late Triassic times, the southern continental margin of the Eastern European Platform was the site of a basaltic volcanism in the Donbas and Fore-Caucasus areas respectively. Both volcanic piles rest unconformably upon Paleoproterozoic and Late Paleozoic units respectively, and emplaced ...

  10. Flame-resistant pure and hybrid woven fabrics from basalt

    Science.gov (United States)

    Jamshaid, H.; Mishra, R.; Militky, J.

    2017-10-01

    This work has been formulated to investigate the burning behavior of different type of fabrics. The main concentration is to see how long the fabric resists after it catches the fire and the propagation of fire can be reduced by using flame resistant fiber i.e basalt. Basalt fiber is an environmental friendly material with low input, high output, low energy consumption and less emission. The goal of present investigations is to show the dependence of fabric flammability on its structure parameters i.e weave type, blend type etc. Fabric weaves have strong effect on flammability properties. Plain weave has the lowest burning rate as the density of the plain weave fabric is more and the structure is tight which gives less chances of flame passing through the fabric. Thermal stability is evaluated with TGA of all hybrid and nonhybrid fabrics and compared. The thermal stability of the basalt fiber is excellent. When comparing thermal analysis curves for hybrid samples it demonstrates that thermal stability of the samples containing basalt is much higher than the non- hybrid samples. Percentage weight loss is less in hybrid samples as compared to non-hybrid samples. The effectiveness of hybridization on samples may be indicated by substantial lowering of the decomposition mass. Correlation was made between flammability with the infrared radiations (IR)

  11. Geochemistry of ultramafic xenoliths in Cenozoic alkali basalts from ...

    Indian Academy of Sciences (India)

    5Department of Leisure Business Management, DeLin Institute of Technology, Taipei 236, Taiwan. ∗. Corresponding author. e-mail: au4300@mail.au.edu.tw. Twelve ultramafic xenoliths in Cenozoic alkali basalts from Jiangsu province, eastern China have been analyzed for major, trace, Sr–Nd isotopic composition and ...

  12. Petrography and petrogenesis of some Indian basaltic achondrites ...

    Indian Academy of Sciences (India)

    oid 4-Vesta (Drake 2001; Barrat 2004; Barrat et al. 2003, 2010; Mittlefehldt 2005; McSween et al. 2011). This is the most abundant class of achon- drites and represents a collection of both volcanic and plutonic rocks formed from basaltic magmas. Keywords. Indian achondrites; HED clan; petrography; mineral chemistry; ...

  13. Depleted basaltic lavas from the proto-Iceland plume, Central East Greenland

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Baker, Joel A.

    2012-01-01

    New geochemical and isotopic data are presented for volumetrically minor, depleted low-Ti basalts that occur in the Plateau Basalt succession of central East Greenland (CEG), formed during the initial stages of opening of the North Atlantic at 55 Ma. The basalts have MORB-like geochemistry (e.g. ...

  14. Spectroscopy of olivine basalts using FieldSpec and ASTER data: A ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 124; Issue 7. Spectroscopy of olivine basalts using FieldSpec and ASTER data: ... Fresh olivine basalt (group A) is characterized by low flat spectral profile with overall low reflectance values (~20%). Spectral profile of altered olivine basalt (group B) shows moderate ...

  15. Geochemical study of young basalts in East Azerbaijan (Northwest of Iran

    Directory of Open Access Journals (Sweden)

    Nasir Amel

    2016-12-01

    Full Text Available The young basalts in East Azerbaijan are placed in West Alborz – Azerbaijan zone. Volcanic activities have extended from the Pliocene to the Quaternary by eruption from fracture systems and faults. Rocks under study are olivine-basalt and trachybasalts. The main minerals are olivine, pyroxene, plagioclase set in glassy or microcrystalline matrix and olivine are present as phenocryst. The textures in the studied rocks are mainly hyaloporphyric, hyalomicrolitic and porphyritic. Trace elements and rare earth elements on spider diagrams have high LREE/HREE ratio. Rare earth elements on diagram display negative slope indicating alkaline nature for the basalts under study. As it may be observed, on tectonic diagrams, the Marand basalts are placed on Island Arc basalt (IAB field, whereas the Ahar, Heris, Kalaibar and Miyaneh basalts are classified as Ocean Island Basalts (OIB and finally the basalts of Sohrol area are plotted on continental rift Basalt (CRB field. The Marand and Sohrol basalts were likely originated from lithospheric - astenospheric mantle with 2 to 5 % partial melting whereas, the Ahar, Heris and Kalaibar basalts having same source experienced 1-2% partial melting rate and the Miyaneh basalts possibly produced from lithospheric mantle with 10-20% partial melting rate pointing to shallow depth of mantle and the higher rate of melting. Based on tectonic setting diagrams, all the rocks studied are plotted in post collisional environments.

  16. Multiple Glass Ceilings

    OpenAIRE

    Russo, Giovanni; Hassink, Wolter

    2011-01-01

    Both vertical (between job levels) and horizontal (within job levels) mobility can be sources of wage growth. We find that the glass ceiling operates at both margins. The unexplained part of the wage gap grows across job levels (glass ceiling at the vertical margin) and across the deciles of the intra-job-level wage distribution (glass ceiling at the horizontal margin). This implies that women face many glass ceilings, one for each job level above the second, and that the glass ceiling is a p...

  17. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  18. Acoustics of glass harmonicas

    Science.gov (United States)

    Rossing, Thomas D.

    2004-05-01

    Glass musical instruments are probably as old as glassmaking. At least as early as the 17th century it was discovered that wine glasses, when rubbed with a wet finger, produced a musical tone. A collection of glasses played in this manner is called a glass harp. Another type of glass harmonica, called the armonica by its inventor Benjamin Franklin, employs glass bowls or cups turned by a horizontal axle, so the performer need only touch the rim of the bowls as they rotate to set them into vibration. We discuss the modes of vibration of both types of glass harmonica, and describe the different sounds that are emitted by rubbing, tapping, or bowing them. Rubbing with a wet finger tends to excite only the (2,0) mode and its harmonics through a ``stick-slip'' process, while tapping excites the other modes as well.

  19. Leaching of glass

    International Nuclear Information System (INIS)

    Hench, L.L.

    1977-01-01

    Understanding surface compositional profiles of glasses over a range of 0-2000 A with a variety of analytical instruments shows that five general types of glass surfaces exist. The surface character of a glass article depends upon bulk composition and environmental history during which surface dealkalization, film formation, and network dissolution can occur. Environmental-surface interactions generally result in complex compositional profiles of all the constituents in a glass. Durable glasses almost always develop a stable surface film which has a higher concentration of network formers than the bulk composition. Compositional effects that are used to improve glass durability usually improve the stability of the surface films. Durability tests or service conditions that lead to film destruction are especially severe for the most silicate glasses. 43 references

  20. New high pressure experiments on sulfide saturation of high-FeO∗ basalts with variable TiO2 contents - Implications for the sulfur inventory of the lunar interior

    Science.gov (United States)

    Ding, Shuo; Hough, Taylor; Dasgupta, Rajdeep

    2018-02-01

    picritic glasses, mare basalts, to young lunar meteorites vary from 2600 to 4800 ppm for basalt equilibration with a pure FeS melt and from 1400 to 2600 ppm for basalt equilibration with a Fe-rich sulfide melt containing 30 wt.% Ni. The measured S contents in these proposed near-primary lunar magmas are lower than the predicted SCSS at the conditions of their last equilibration with the lunar mantle, indicating no sulfide retention in the lunar mantle source during partial melting. Sulfide exhaustion during partial melting in the lunar mantle also supports the notion that the bulk silicate moon is depleted in highly siderophile elements. Based on the measured S contents and the estimated degree of melting, the estimated S contents for the mantle source of A15 green glass and A15 mare basalts is 10-23 ppm; for A17 orange glass is 25-62 ppm, for A12 mare basalts is 27-92 ppm, and for A11 basalt is 35-120 ppm. Consideration of SCSS decrease due to the presence of Ni in the sulfide melt does not change these mantle S abundance estimates for falls near the lower end of the S content of the depleted terrestrial mantle such as the MORB source.

  1. The role of natural glasses as analogues in projecting the long-term alteration of high-level nuclear waste glasses: Part 1

    International Nuclear Information System (INIS)

    Mazer, J.J.

    1993-01-01

    The common observation of glasses persisting in natural environments for long periods of time (up to tens of millions of years) provides compelling evidence that these materials can be kinetically stable in a variety of subsurface environments. This paper reviews how natural and historical synthesized glasses can be employed as natural analogues for understanding and projecting the long-term alteration of high-level nuclear waste glasses. The corrosion of basaltic glass results in many of the same alteration features found in laboratory testing of the corrosion of high-level radioactive waste glasses. Evidence has also been found indicating similarities in the rate controlling processes, such as the effects of silica concentration on corrosion in groundwater and in laboratory leachates. Naturally altered rhyolitic glasses and tektites provide additional evidence that can be used to constrain estimates of long-term waste glass alteration. When reacted under conditions where water is plentiful, the corrosion for these glasses is dominated by network hydrolysis, while the corrosion is dominated by molecular water diffusion and secondary mineral formation under conditions where water contact is intermittent or where water is relatively scarce. Synthesized glasses that have been naturally altered result in alkali-depleted alteration features that are similar to those found for natural glasses and for nuclear waste glasses. The characteristics of these alteration features appear to be dependent on the alteration conditions which affect the dominant reaction processes during weathering. In all cases, care must be taken to ensure that the information being provided by natural analogues is related to nuclear waste glass corrosion in a clear and meaningful way

  2. Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

    Science.gov (United States)

    Vye-Brown, C.; Self, S.; Barry, T. L.

    2013-03-01

    The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

  3. Chemical corrosion of highly radioactive borosilicate nuclear waste glass under simulated repository conditions

    International Nuclear Information System (INIS)

    Werme, L.; Bjoerner, I.K.; Bart, G.; Zwicky, H.U.; Grambow, B.; Lutze, W.; Ewing, R.C.; Magrabi, C.

    1990-01-01

    This review summarizes the results of the joint Japanese (Central Research Institute of Electric Power Industry, CRIEPI, Tokyo), Swiss (National Cooperative for the Storage of Radioactive Waste, NAGRA, Baden), Swedish (Swedish Nuclear Fuel and Waste Management Company, SKB, Stockholm) international 'JSS' project on the determination of the chemical durability of the French nuclear waste borosilicate glass, which was completed in 1988. Radioactive and non-radioactive glass specimens were investigated. A data base was created with results from glass corrosion tests performed with different water compositions, pH values, temperatures, sample surface areas (S), solution volumes (V), and flow rates. Glass corrosion tests were performed with and without bentonite and/or steel corrosion products present. Variation of the glass composition was taken into account by including the borosilicate glass 'MW' in the investigations, formulated by British Nuclear Fuels, plc. An understanding was achieved of the glass corrosion process in general, and of the performance of the French glass under various potential disposal conditions in particular. A special effort was made to establish a corrosion data base, using high S/V ratios in the experiments in order to understand the glass durability in the long term. A computer program, GLASSOL, was developed, based on a dissolution-precipitation model, to calculate the glass water reaction. Fair agreement between observations and the model calculations was achieved. Use of a constant (time-independent) long-term rate was justified by observations on naturally altered basaltic glasses of great age, which were compatible with what was inferred from experiments with nuclear waste glasses in the laboratory. A fractured glass block would not be altered within 10 000 years at 90 degree C (flow rate <100 L/year)

  4. Surface modification of basalt with silane coupling agent on asphalt mixture moisture damage

    Energy Technology Data Exchange (ETDEWEB)

    Min, Yahong; Fang, Ying; Huang, Xiaojun; Zhu, Yinhui; Li, Wensheng [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Yuan, Jianmin [College of Materials Engineering, Hunan University, Changsha, 410082 (China); Tan, Ligang [College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082 (China); Wang, Shuangyin [State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wu, Zhenjun, E-mail: wooawt@163.com [College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • A new silane coupling agent was synthesized based on KH570. • Basalt surface was modified using the new silane coupling agent. • Chemical bond between basalt and the new silane coupling agent was formed. • Asphalt mixture which used modified basalt show superior water stability. - Abstract: A new silane coupling agent was synthesized based on γ-(methacryloyloxy) propyltrimethoxysilane (KH570). The surface of basalt rocks was modified by KH570 and the new silane coupling agent (NSCA), and the interfacial interaction between silane coupling agent and basalt was also studied. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis showed that the silane coupling agent molecule bound strongly with basalt rocks. Scanning electronic microscopy (SEM) observation showed that a thin layer of coupling agent was formed on the surface of modified basalt. The boiling test and immersion Marshall test confirmed that the moisture sensitivity of basalt modified with the new silane coupling agent increased more significantly than that untreated and treated with KH570. The Retained Marshall Strength of basalt modified with the new coupling agent increased from 71.74% to 87.79% compared with untreated basalt. The results indicated that the new silane coupling agent played an important role in improving the interfacial performance between basalt and asphalt.

  5. Optimized Synthesis of Foam Glass from Recycled CRT Panel Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Most of the panel glass from cathode ray tubes (CRTs) is landfilled today. Instead of landfilling, the panel glass can be turned into new environment-friendly foam glass. Low density foam glass is an effective heat insulating material and can be produced just by using recycle glass and foaming ad...... calorimetric data show that panel glass possesses good stability against crystallisation. X-ray diffraction data show that the foaming agents enhance the surface crystallisation of the panel glass. We find that the crystallisation impedes the formation of low density foam glass.......Most of the panel glass from cathode ray tubes (CRTs) is landfilled today. Instead of landfilling, the panel glass can be turned into new environment-friendly foam glass. Low density foam glass is an effective heat insulating material and can be produced just by using recycle glass and foaming...

  6. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria

    International Nuclear Information System (INIS)

    Asfahani, Jamal

    2011-01-01

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range.

  7. Kinetics of iron redox reaction in silicate melts: A high temperature Xanes study on an alkali basalt

    Energy Technology Data Exchange (ETDEWEB)

    Cochain, B; Neuville, D R; Roux, J; Strukelj, E; Richet, P [Physique des Mineraux et Magmas, Geochimie-Cosmochimie, CNRS-IPGP, 4 place Jussieu, 75005 Paris (France); Ligny, D de [Universite Claude Bernard Lyon 1, LPCML, F-69622 Villeurbanne (France); Baudelet, F, E-mail: cochain@ipgp.jussieu.f [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin (France)

    2009-11-15

    In Earth and Materials sciences, iron is the most important transition element. Glass and melt properties are strongly affected by iron content and redox state with the consequence that some properties (i.e. viscosity, heat capacity, crystallization...) depend not only on the amounts of Fe{sup 2+} and Fe{sup 3+}, but also on the coordination state of these ions. In this work we investigate iron redox reactions through XANES experiments at the K-edge of iron. Using a high-temperature heating device, pre-edge of XANES spectra exhibits definite advantages to make in-situ measurements and to determine the evolution of redox state with time, temperature and composition of synthetic silicate melts. In this study, new kinetics measurements are presented for a basalt melt from the 31,000-BC eruption of the Puy de Lemptegy Volcano in France. These measurements have been made between 773 K and at superliquidus temperatures up to 1923 K.

  8. Homogeneity of Inorganic Glasses

    DEFF Research Database (Denmark)

    Jensen, Martin; Zhang, L.; Keding, Ralf

    2011-01-01

    Homogeneity of glasses is a key factor determining their physical and chemical properties and overall quality. However, quantification of the homogeneity of a variety of glasses is still a challenge for glass scientists and technologists. Here, we show a simple approach by which the homogeneity...... of different glass products can be quantified and ranked. This approach is based on determination of both the optical intensity and dimension of the striations in glasses. These two characteristic values areobtained using the image processing method established recently. The logarithmic ratio between...... the dimension and the intensity is used to quantify and rank the homogeneity of glass products. Compared with the refractive index method, the image processing method has a wider detection range and a lower statistical uncertainty....

  9. Americium migration in basalt and implications to repository risk analysis

    International Nuclear Information System (INIS)

    Rickert, P.G.

    1980-01-01

    Experiments were performed with americium as a minor component in groundwater. Batch adsorption, migration through column, and filtration experiments were performed. It was determined in batch experiments that americium is strongly adsorbed from solution. It was determined with filtration experiments that large percentages of the americium concentrations suspended by the contact solutions in batch experiments and suspended by the infiltrating groundwater in migration experiments were associated with particulate. Filtration was determined to be the primary mode of removal of americium from infiltrating groundwater in a column of granulated basalt (20 to 50 mesh) and an intact core of permeable basalt. Fractionally, 0.46 and 0.22 of the americium component in the infiltrating groundwater was transported through the column and core respectively. In view of these filtration and migration experiment results, the concept of K/sub d/ in the chromatographic sense is meaningless for predicting americium migration in bedrock by groundwater transport at near neutral pH

  10. Continental flood basalts derived from the hydrous mantle transition zone.

    Science.gov (United States)

    Wang, Xuan-Ce; Wilde, Simon A; Li, Qiu-Li; Yang, Ya-Nan

    2015-07-14

    It has previously been postulated that the Earth's hydrous mantle transition zone may play a key role in intraplate magmatism, but no confirmatory evidence has been reported. Here we demonstrate that hydrothermally altered subducted oceanic crust was involved in generating the late Cenozoic Chifeng continental flood basalts of East Asia. This study combines oxygen isotopes with conventional geochemistry to provide evidence for an origin in the hydrous mantle transition zone. These observations lead us to propose an alternative thermochemical model, whereby slab-triggered wet upwelling produces large volumes of melt that may rise from the hydrous mantle transition zone. This model explains the lack of pre-magmatic lithospheric extension or a hotspot track and also the arc-like signatures observed in some large-scale intracontinental magmas. Deep-Earth water cycling, linked to cold subduction, slab stagnation, wet mantle upwelling and assembly/breakup of supercontinents, can potentially account for the chemical diversity of many continental flood basalts.

  11. The solubility of olivine in basaltic liquids - An ionic model

    Science.gov (United States)

    Herzberg, C. T.

    1979-01-01

    A model is presented which enables the temperature at which olivine is in equilibrium with any alkali-depleted basaltic compound to be calculated to within + or - 30 C. It is noted that the error increases substantially when applied to terrestrial basalts which contain several weight percent alkalis. In addition the model predicts and quantifies the reduced activity of SiO4(4-) monomers due to increasing SiO2 concentrations in the melt. It is shown that the coordination of alumina in melts which precipitate olivine only appears to be dominantly octahedral, while titanium acts as a polmerizing agent by interconnecting previously isolated SiO4(4-) monomers. It is concluded that the model is sufficiently sensitive to show that there are small repulsive forces between Mg(2+) and calcium ions which are in association with normative diopside in the melt.

  12. Diamond turning of glass

    Energy Technology Data Exchange (ETDEWEB)

    Blackley, W.S.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the critical cutting depth concepts for single point diamond turning of brittle, amorphous materials. Inorganic glasses and a brittle, thermoset polymer (organic glass) are the principal candidate materials. Interrupted cutting tests similar to those done in earlier research are Ge and Si crystals will be made to obtain critical depth values as a function of machining parameters. The results will provide systematic data with which to assess machining performance on glasses and amorphous materials

  13. Fractography of glass

    CERN Document Server

    Tressler, Richard

    1994-01-01

    As the first major reference on glass fractography, contributors to this volume offer a comprehensive account of the fracture of glass as well as various fracture surface topography Contributors discuss optical fibers, glass containers, and flatglass fractography In addition, papers explore fracture origins; the growth of the original flaws of defects; and macroscopic fracture patterns from which fracture patterns evolve This volume is complete with photographs and schematics

  14. Glass microspheres for brachytherapy

    International Nuclear Information System (INIS)

    Prado, Miguel O.; Prastalo, Simon; Blaumann, Herman; Longhino, Juan M.; Repetto Llamazares, A.H.V.

    2007-01-01

    We developed the capacity to produce glass microspheres containing in their structure one or more radioactive isotopes useful for brachytherapy. We studied the various facts related with their production: (Rare earth) alumino silicate glass making, glass characterization, microspheres production, nuclear activation through (n,γ) nuclear reactions, mechanical characterization before and after irradiation. Corrosion tests in simulated human plasma and mechanical properties characterization were done before and after irradiation. (author) [es

  15. Glass to contain wastes

    International Nuclear Information System (INIS)

    Moncouyoux, M.; Jacquet-Francillon, M.

    1994-01-01

    Here are the tables and figures presented during the conference on the glass to confine high level radioactive wastes: definition, fabrication, storage and disposal. The composition of glasses are detailed, their properties and the vitrification proceeding. The behaviour of these glasses in front of water, irradiation and heat are shown. The characteristics of parcels are given according to the radiation protection rule, ALARA principle, the concept of multi-barriers and the geological stability

  16. Supertoxic Flood Basalts: The CAMP - Siberian Trap Connection

    Science.gov (United States)

    Puffer, J. H.

    2007-12-01

    Several diverse magma types are represented throughout the CAMP and Siberian Trap LIPs, however, the main extrusive phase of each province is highly unusual among continental flood basalts. The most widespread extrusions were intermediate titanium (ITi-type) CAMP basalt and the lower portion of the Upper Sequence of Siberian Trap. New and recently published data indicate that the geochemistry and petrology of these basalt suites closely resemble each other and infer similar origins. The basalts are characterized by strong negative Nb- Ta anomalies and unusual island arc-like depletion in high field strength elements, particularly Ti, plotted on spider diagrams. The geochemical data is consistent with significant contributions from subducted slabs into the magma source regions. If contaminated, volatile enriched mantle wedges were trapped beneath thick continental plates during the assembly of Pangea, fertile magma sources would have remained dormant until decompression melting was triggered during failed rift, then early rift stages of continental plate disassembly. The combination of volatile enriched sources and highly extensional tectonism would create rare perfect storms of toxicity. Calculated low viscosities assuming negligible carbon dioxide are consistent with rapid crustal penetration. Resulting aphyric melts extruded at enormous effusive rates as thick sub-parallel flows across wide subareal terrains through fissures extending several hundred km in length. High fountain heights would afford ample opportunity for efficient degassing, perhaps into the stratosphere. When the supply of volatile flux was exhausted magmatism ceased. The mass extinctions that coincide with CAMP and Siberian volcanism contrast with some large plume and superplume events that correlate with expansions of biodiversity. This may be due in part to contrasting magma access to sources of toxic volatiles, particularly sulfur concentrations in anoxic subducted sediments.

  17. Basalt-trachybasalt samples in Gale Crater, Mars

    International Nuclear Information System (INIS)

    Edwards, Peter H.; Anderson, Ryan B.; Dyar, Darby

    2017-01-01

    The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single-laser-shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO 2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO 2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg# = 27 but with a secondary concentration of basaltic material, with a focus of compositions around Mg# = 54. We suggest that all of these igneous rocks resulted from low-pressure, olivine-dominated fractionation of Adirondack (MER) class-type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe-rich, relatively low-Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine-grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. Finally, the Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces.

  18. Genetic aspects of basalts from the Carlsberg Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    and three decades later, other workers 5 ? 7 reported the pre s ence of ultrabasics, gab - bros, dolerites, spilites and metamorphosed effusiv es besides basalts along different segments of the CR. Isotopes and rare earth element contents of rocks..., although less dominant, usually occurs as anhedral to euhedral, skeletal and la n tern - shaped forms in the groundmass and as micro - pheno - crysts while zoned olivine is rare. The ore minerals are mainly pyrite, chalcopyrite and magnetite 17...

  19. Characterization of iron-enriched synthetic basalt for transuranic containment

    International Nuclear Information System (INIS)

    Flinn, J.E.; Henslee, S.P.; Kelsey, P.V.; Tallman, R.L.; Welch, J.M.

    1980-01-01

    In the slagging pyrolytic incineration process, combustibles are burned and noncombustibles, including metals, are oxidized into a molten , an electromelter, where the molten slag, with further processing conducted in a heated tundish, e.g. is allowed to homogenize (within a reasonable time period) and then cast into large, cylindrical metal containers. Analyses of Idaho National Engineering Laboratory waste slags show them similar in composition and appearance to natural basalts, but rich in iron. The electromelt process and the resulting iron-rich castings offer great promise for rendering nuclear waste into a stable form. The process offers great flexibility with regard to both compositional variation of the incoming waste and the high rates at which the waste can be introduced and cast. The cast product, a fine-grained basalt-like material, shows excellent homogeneity with little or no reaction to the steel containment. The preliminary mechanical and chemical durability data show the form to have adequate containment properties for TRU waste. However, work presently underway to improve these properties through additives and controlled cooling cycles has greatly enhanced the durability of the waste form. Furthermore, recent evidence indicates that divalent iron (Fe 2+ ) included in the crystalline phases of granites and basalts imparts a resistance to leaching of uranium and other actinide ions

  20. The Age of Rift-Related Basalts in East Antarctica

    Science.gov (United States)

    Leitchenkov, G. L.; Belyatsky, B. V.; Kaminsky, V. D.

    2018-01-01

    The Lambert Rift, which is a large intracontinental rift zone in East Antarctica, developed over a long period of geological time, beginning from the Late Paleozoic, and its evolution was accompanied by magmatic activity. The latest manifestation of magmatism is eruption of alkaline olivine-leucite basalts on the western side of the Lambert Rift; Rb-Sr dating referred its time to the Middle Eocene, although its genesis remained vague. In order to solve this problem, we found geochronometer minerals in basaltic samples and 68 apatite grains appeared to be suitable for analysis. Their ages and ages of host basalts, determined by the U-Pb local method on the SIMS SHRIMP-II, were significantly different (323 ± 31 Ma) from those assumed earlier. This age corresponds to the earliest stage of crustal extension in East Antarctica and to most of Gondwana. The new data crucially change the ideas about the evolution of Lambert Rift and demonstrate the ambiguity of K-Ar dates of the alkali effusive formed under long-term rifting.

  1. Interim reclamation report, Basalt Waste Isolation project: Boreholes, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-03-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. An extensive site characterization program was begun to determine the feasibility of using the basalts beneath the Hanford Site for the repository. Site research focused primarily on determining the direction and speed of groundwater movement, the uniformity of basalt layers, and tectonic stability. Some 98 boreholes were sited, drilled, deepened, or modified by BWIP between 1977 and 1988 to test the geologic properties of the Site. On December 22, 1987, President Reagan signed into law the Nuclear Waste Policy Amendments Act of 1987, which effectively stopped all repository-related activities except reclamation of disturbed lands at the Hanford Site. This report describes the development of the reclamation program for the BWIP boreholes, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 48 refs., 28 figs., 14 tabs.

  2. Basalt Pb isotope analysis and the prehistoric settlement of Polynesia.

    Science.gov (United States)

    Weisler, M I; Woodhead, J D

    1995-01-01

    The prehistoric settlement of the Pacific Ocean has intrigued scholars and stimulated anthropological debate for the past two centuries. Colonized over a few millennia during the mid to late Holocene, the islands of the Pacific--displaying a wide diversity of geological and biotic variability--provided the stage for endless "natural experiments" in human adaptation. Crucial to understanding the evolution and transformation of island societies is documenting the relative degree of interisland contacts after island colonization. In the western Pacific, ideal materials for archaeologically documenting interisland contact--obsidian, pottery, and shell ornaments--are absent or of limited geographic distribution in Polynesia. Consequently, archaeologists have relied increasingly on fine-grained basalt artifacts as a means for documenting colonization routes and subsequent interisland contacts. Routinely used x-ray fluorescence characterization of oceanic island basalt has some problems for discriminating source rocks and artifacts in provenance studies. The variation in trace and major element abundances is largely controlled by near-surface magma-chamber processes and is broadly similar between most oceanic islands. We demonstrate that Pb isotope analysis accurately discriminates rock source and is an excellent technique for charting the scale, frequency, and temporal span of imported fine-grained basalt artifacts found throughout Polynesia. The technique adds another tool for addressing evolutionary models of interaction, isolation, and cultural divergence in the eastern Pacific. PMID:7892194

  3. Basalt Waste Isolation Project. Annual report, fiscal year 1980

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    During this fiscal year the information available in the fields of geology and hydrology of the Columbia Plateau was consolidated and two reports were issued summarizing this information. In addition, the information on engineered barriers was consolidated and a report summarizing the research to date on waste package development and design of borehole seals was prepared. The waste package studies, when combined with the hydrologic integration, revealed that even under extreme disruptive conditions, a repository in basalt with appropriately designed waste packages can serve as an excellent barrier for containment of radionuclides for the long periods of time required for waste isolation. On July 1, 1980, the first two heater tests at the Near-Surface Test Facility were started and have been successfully operated to this date. The papers on the Near-Surface Test Facility section of this report present the results of the equipment installed and the preliminary results of the testing. In October 1979, the US Department of Energy selected the joint venture of Kaiser Engineers/Parsons Brinckerhoff Quade and Douglas, Inc., to be the architect-engineer to produce a conceptual design of a repository in basalt. During the year, this design has progressed and concept selection has now been completed. This annual report presents a summary of the highlights of the work completed during fiscal year 1980. It is intended to supplement and summarize the nearly 200 papers and reports that have been distributed to date as a part of the Basalt Waste Isolation Project studies.

  4. Temperature profile around a basaltic sill intruded into wet sediments

    Science.gov (United States)

    Baker, Leslie; Bernard, Andrew; Rember, William C.; Milazzo, Moses; Dundas, Colin M.; Abramov, Oleg; Kestay, Laszlo P.

    2015-01-01

    The transfer of heat into wet sediments from magmatic intrusions or lava flows is not well constrained from field data. Such field constraints on numerical models of heat transfer could significantly improve our understanding of water–lava interactions. We use experimentally calibrated pollen darkening to measure the temperature profile around a basaltic sill emplaced into wet lakebed sediments. It is well known that, upon heating, initially transparent palynomorphs darken progressively through golden, brown, and black shades before being destroyed; however, this approach to measuring temperature has not been applied to volcanological questions. We collected sediment samples from established Miocene fossil localities at Clarkia, Idaho. Fossils in the sediments include pollen from numerous tree and shrub species. We experimentally calibrated changes in the color of Clarkia sediment pollen and used this calibration to determine sediment temperatures around a Miocene basaltic sill emplaced in the sediments. Results indicated a flat temperature profile above and below the sill, with T > 325 °C within 1 cm of the basalt-sediment contact, near 300 °C at 1–2 cm from the contact, and ~ 250 °C at 1 m from the sill contact. This profile suggests that heat transport in the sediments was hydrothermally rather than conductively controlled. This information will be used to test numerical models of heat transfer in wet sediments on Earth and Mars.

  5. Physical abrasion of mafic minerals and basalt grains: application to Martian aeolian deposits

    Science.gov (United States)

    Cornwall, Carin; Bandfield, Joshua L.; Titus, Timothy N.; Schreiber, B. C.; Montgomery, D.R.

    2015-01-01

    Sediment maturity, or the mineralogical and physical characterization of sediment deposits, has been used to locate sediment source, transport medium and distance, weathering processes, and paleoenvironments on Earth. Mature terrestrial sands are dominated by quartz, which is abundant in source lithologies on Earth and is physically and chemically stable under a wide range of conditions. Immature sands, such as those rich in feldspars or mafic minerals, are composed of grains that are easily physically weathered and highly susceptible to chemical weathering. On Mars, which is predominately mafic in composition, terrestrial standards of sediment maturity are not applicable. In addition, the martian climate today is cold, dry and sediments are likely to be heavily influenced by physical weathering rather than chemical weathering. Due to these large differences in weathering processes and composition, martian sediments require an alternate maturity index. Abrason tests have been conducted on a variety of mafic materials and results suggest that mature martian sediments may be composed of well sorted, well rounded, spherical basalt grains. In addition, any volcanic glass present is likely to persist in a mechanical weathering environment while chemically altered products are likely to be winnowed away. A modified sediment maturity index is proposed that can be used in future studies to constrain sediment source, paleoclimate, mechanisms for sediment production, and surface evolution. This maturity index may also provide details about erosional and sediment transport systems and preservation processes of layered deposits.

  6. 3-D high-speed imaging of volcanic bomb trajectory in basaltic explosive eruptions

    Science.gov (United States)

    Gaudin, D.; Taddeucci, J; Houghton, Bruce F.; Orr, Tim R.; Andronico, D.; Del Bello, E.; Kueppers, U.; Ricci, T.; Scarlato, P.

    2016-01-01

    Imaging, in general, and high speed imaging in particular are important emerging tools for the study of explosive volcanic eruptions. However, traditional 2-D video observations cannot measure volcanic ejecta motion toward and away from the camera, strongly hindering our capability to fully determine crucial hazard-related parameters such as explosion directionality and pyroclasts' absolute velocity. In this paper, we use up to three synchronized high-speed cameras to reconstruct pyroclasts trajectories in three dimensions. Classical stereographic techniques are adapted to overcome the difficult observation conditions of active volcanic vents, including the large number of overlapping pyroclasts which may change shape in flight, variable lighting and clouding conditions, and lack of direct access to the target. In particular, we use a laser rangefinder to measure the geometry of the filming setup and manually track pyroclasts on the videos. This method reduces uncertainties to 10° in azimuth and dip angle of the pyroclasts, and down to 20% in the absolute velocity estimation. We demonstrate the potential of this approach by three examples: the development of an explosion at Stromboli, a bubble burst at Halema'uma'u lava lake, and an in-flight collision between two bombs at Stromboli.

  7. H2O solubility in basalt at upper mantle conditions

    Science.gov (United States)

    Mitchell, Alexandra L.; Gaetani, Glenn A.; O'Leary, Julie A.; Hauri, Erik H.

    2017-10-01

    This study presents a new experimental approach for determining H2O solubility in basaltic melt at upper mantle conditions. Traditional solubility experiments are limited to pressures of 600 MPa or less because it is difficult to reliably quench silicate melts containing greater than 10 wt% dissolved H2O. To overcome this limitation, our approach relies on the use of secondary ion mass spectrometry to measure the concentration of H dissolved in olivine and on using the measured H in olivine as a proxy for the concentration of H2O in the co-existing basaltic melt. The solubility of H2O in the melt is determined by performing a series of experiments at a single pressure and temperature with increasing amounts of liquid H2O added to each charge. The point at which the concentration of H in the olivine first becomes independent of the amount of initial H2O content of the charge (added + adsorbed H2O) indicates its solubility in the melt. Experiments were conducted by packing basalt powder into a capsule fabricated from San Carlos olivine, which was then pressure-sealed inside a Ni outer capsule. Our experimental results indicate that at 1000 MPa and 1200 °C, the solubility of H2O in basaltic melt is 20.6 ± 0.9 wt% (2 × standard deviation). This concentration is considerably higher than predicted by most solubility models but defines a linear relationship between H2O fugacity and the square of molar H2O solubility when combined with solubility data from lower pressure experiments. Further, our solubility determination agrees with melting point depression determined experimentally by Grove et al. (2006) for the H2O-saturated peridotite solidus at 1000 MPa. Melting point depression calculations were used to estimate H2O solubility in basalt along the experimentally determined H2O-saturated peridotite solidus. The results suggest that a linear relationship between H2O fugacity and the square of molar solubility exists up to 1300 MPa, where there is an inflection point

  8. Assessing Eruption Column Height in Ancient Flood Basalt Eruptions

    Science.gov (United States)

    Glaze, Lori S.; Self, Stephen; Schmidt, Anja; Hunter, Stephen J.

    2015-01-01

    A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at approximately 45 deg N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the approximately 180 km of known Roza fissure length could have supported approximately 36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (approximately 66 Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained

  9. A comparison of the performance of nuclear waste glasses by modeling

    International Nuclear Information System (INIS)

    Grambow, B.; Strachan, D.M.

    1988-01-01

    A model selected for the licensing process must be based on a physical and chemical understanding of the glass corrosion mechanism. The purpose of this paper is to show that a dissolution/precipitation model can be used to better understand the effects of various system variables on glass dissolution. The application and validation of this model are also discussed. A dissolution/precipitation model developed appears applicable to experiments with a wide range of solution compositions as well as to more complex systems, such as the bentonite/glass/water system the steel corrosion product/glass/water system, or the dissolution of natural basalt glass in a geologic environment. This model is based on solution chemistry and transition state theory. The theoretical background of this model is discussed elsewhere and is used to describe the dissolution behavior of three nuclear waste glasses. These glasses were selected because they represent a wide range of behavior and, therefore, could be used to illustrate the capabilities of the dissolution/precipitation model. The effects of parameters, such as temperature and starting solution composition, on the dissolution behavior of glass are also discussed. 27 refs., 10 figs., 1 tab

  10. On the potential for CO2 mineral storage in continental flood basalts - PHREEQC batch- and 1D diffusion-reaction simulations.

    Science.gov (United States)

    Van Pham, Thi Hai; Aagaard, Per; Hellevang, Helge

    2012-06-14

    Continental flood basalts (CFB) are considered as potential CO2 storage sites because of their high reactivity and abundant divalent metal ions that can potentially trap carbon for geological timescales. Moreover, laterally extensive CFB are found in many place in the world within reasonable distances from major CO2 point emission sources.Based on the mineral and glass composition of the Columbia River Basalt (CRB) we estimated the potential of CFB to store CO2 in secondary carbonates. We simulated the system using kinetic dependent dissolution of primary basalt-minerals (pyroxene, feldspar and glass) and the local equilibrium assumption for secondary phases (weathering products). The simulations were divided into closed-system batch simulations at a constant CO2 pressure of 100 bar with sensitivity studies of temperature and reactive surface area, an evaluation of the reactivity of H2O in scCO2, and finally 1D reactive diffusion simulations giving reactivity at CO2 pressures varying from 0 to 100 bar.Although the uncertainty in reactive surface area and corresponding reaction rates are large, we have estimated the potential for CO2 mineral storage and identified factors that control the maximum extent of carbonation. The simulations showed that formation of carbonates from basalt at 40 C may be limited to the formation of siderite and possibly FeMg carbonates. Calcium was largely consumed by zeolite and oxide instead of forming carbonates. At higher temperatures (60 - 100 C), magnesite is suggested to form together with siderite and ankerite. The maximum potential of CO2 stored as solid carbonates, if CO2 is supplied to the reactions unlimited, is shown to depend on the availability of pore space as the hydration and carbonation reactions increase the solid volume and clog the pore space. For systems such as in the scCO2 phase with limited amount of water, the total carbonation potential is limited by the amount of water present for hydration of basalt.

  11. On the potential for CO2 mineral storage in continental flood basalts – PHREEQC batch- and 1D diffusion–reaction simulations

    Science.gov (United States)

    2012-01-01

    Continental flood basalts (CFB) are considered as potential CO2 storage sites because of their high reactivity and abundant divalent metal ions that can potentially trap carbon for geological timescales. Moreover, laterally extensive CFB are found in many place in the world within reasonable distances from major CO2 point emission sources. Based on the mineral and glass composition of the Columbia River Basalt (CRB) we estimated the potential of CFB to store CO2 in secondary carbonates. We simulated the system using kinetic dependent dissolution of primary basalt-minerals (pyroxene, feldspar and glass) and the local equilibrium assumption for secondary phases (weathering products). The simulations were divided into closed-system batch simulations at a constant CO2 pressure of 100 bar with sensitivity studies of temperature and reactive surface area, an evaluation of the reactivity of H2O in scCO2, and finally 1D reactive diffusion simulations giving reactivity at CO2 pressures varying from 0 to 100 bar. Although the uncertainty in reactive surface area and corresponding reaction rates are large, we have estimated the potential for CO2 mineral storage and identified factors that control the maximum extent of carbonation. The simulations showed that formation of carbonates from basalt at 40 C may be limited to the formation of siderite and possibly FeMg carbonates. Calcium was largely consumed by zeolite and oxide instead of forming carbonates. At higher temperatures (60 – 100 C), magnesite is suggested to form together with siderite and ankerite. The maximum potential of CO2 stored as solid carbonates, if CO2 is supplied to the reactions unlimited, is shown to depend on the availability of pore space as the hydration and carbonation reactions increase the solid volume and clog the pore space. For systems such as in the scCO2 phase with limited amount of water, the total carbonation potential is limited by the amount of water present for hydration of basalt

  12. On the potential for CO2 mineral storage in continental flood basalts – PHREEQC batch- and 1D diffusion–reaction simulations

    Directory of Open Access Journals (Sweden)

    Van Pham Thi

    2012-06-01

    Full Text Available Abstract Continental flood basalts (CFB are considered as potential CO2 storage sites because of their high reactivity and abundant divalent metal ions that can potentially trap carbon for geological timescales. Moreover, laterally extensive CFB are found in many place in the world within reasonable distances from major CO2 point emission sources. Based on the mineral and glass composition of the Columbia River Basalt (CRB we estimated the potential of CFB to store CO2 in secondary carbonates. We simulated the system using kinetic dependent dissolution of primary basalt-minerals (pyroxene, feldspar and glass and the local equilibrium assumption for secondary phases (weathering products. The simulations were divided into closed-system batch simulations at a constant CO2 pressure of 100 bar with sensitivity studies of temperature and reactive surface area, an evaluation of the reactivity of H2O in scCO2, and finally 1D reactive diffusion simulations giving reactivity at CO2 pressures varying from 0 to 100 bar. Although the uncertainty in reactive surface area and corresponding reaction rates are large, we have estimated the potential for CO2 mineral storage and identified factors that control the maximum extent of carbonation. The simulations showed that formation of carbonates from basalt at 40 C may be limited to the formation of siderite and possibly FeMg carbonates. Calcium was largely consumed by zeolite and oxide instead of forming carbonates. At higher temperatures (60 – 100 C, magnesite is suggested to form together with siderite and ankerite. The maximum potential of CO2 stored as solid carbonates, if CO2 is supplied to the reactions unlimited, is shown to depend on the availability of pore space as the hydration and carbonation reactions increase the solid volume and clog the pore space. For systems such as in the scCO2 phase with limited amount of water, the total carbonation potential is limited by the amount of water present

  13. Relaxations in spin glasses: Similarities and differences from ordinary glasses

    International Nuclear Information System (INIS)

    Ngai, K.L.; Rajagopal, A.K.; Huang, C.Y.

    1984-01-01

    Relaxation phenomena have become a major concern in the physics of spin glasses. There are certain resemblances of these relaxation properties to those of ordinary glasses. In this work, we compare the relaxation properties of spin glasses near the freezing temperature with those of glasses near the glass transition temperature. There are similarities between the two types of glasses. Moreover, the relaxation properties of many glasses and spin glasses are in conformity with two coupled ''universality'' relations predicted by a recent model of relaxations in condensed matter

  14. Evaluation of Structural Cellular Glass

    Science.gov (United States)

    Adams, M. A.; Zwissler, J. G.

    1984-01-01

    Preliminary design information presented. First report discusses state of structural-cellular-glass programs as of June 1979. Second report gives further details of program to develop improved cellular glasses and to characterize properties of glasses and commercially available materials.

  15. Getting Started with Glass

    Science.gov (United States)

    White, Heather

    2007-01-01

    The metamorphosis of glass when heated is a magical process to students, yet teachers are often reluctant to try it in class. The biggest challenge in working with glass in the classroom is to simplify procedures just enough to ensure student success while maintaining strict safety practices so no students are injured. Project concepts and safety…

  16. Radioresistance of inorganic glasses

    International Nuclear Information System (INIS)

    Vorob'ev, A.A.; Zavadovskaya, E.K.; Fedorov, B.V.; Starodubtsev, V.A.

    1977-01-01

    Regularities are considered in the variation of properties of glass due to irradiations. On the basis of previous theoretical statements and experimental investigations, it is inferred that the irradiation resistance of glasses of the same type, synthesis conditions, content of impurities and amount of imperfections, is a function of the ''element-oxygen'' bond energy. The irradiation resistance depends on the number and the nature of glass structure imperfections. The averaged level of bonding forces is indicative of the glass formation temperature; the imperfections in glasses are formed in structure elements whose amount predominates as compared to the others. Electric charges which accumulate on the crack surface tend to increase its size, thus lessening even further the electric strength of the dielectric. The greater the irradiation time, the greater the number of irradiation imperfections causing a drop in the electric strength of glass. When choosing a glass for service in a radiation field, it is necessary to select those of a highest temperature of glass formation and with a least amount of imperfections

  17. Electric glass capturing markets

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, K.; Wikstroem, T.

    1996-11-01

    Electric glass has found its place on the construction market. In public buildings, electrically heatable windows are becoming the leading option for large glass walls. Studies on detached houses, both new and renovated, show that floor heating combined with electrically heatable windowpanes is the best choice with respect to resident`s comfort. (orig.)

  18. Dramatic Stained Glass.

    Science.gov (United States)

    Prater, Michael

    2002-01-01

    Describes an art project that is appropriate for students in fifth through twelfth grade in which they create Gothic-style stained-glass windows. Discusses how college students majoring in elementary education created stained-glass windows. Addresses how to adapt this lesson for younger students. (CMK)

  19. Polymorphism in glasses

    International Nuclear Information System (INIS)

    Landa, L.M.; Nikolaeva, I.N.

    1979-01-01

    To defect phase interfaces and spasmodic properties change, the inhomogeneity and the second radiation effects in quartz glass, metamict phase and intermediate states have been investigated. When irradiating with fast neutrons the transformation of quartz glass - metamict phase occurs completely. The transformation is completed at 2x10 20 part./cm 2 dose. Thermal treatment not only increases the number of inhomogeneities but also results in increasing quartz glass density. Annealing transforms the metamict phase into common quartz glass at 1400 K. The fact, that thermal treatment results in the complete transformation of metamict phase into quartz glass, and the inverse transformation occurs only partially, is quite regular, as the metamict phase has a lesser entropy and is a more ordered state. It is shown that different amorphous phases of a chemical composition have different structures and properties, that there are interfaces between them, and the transformation from one state to another in microvolumes is realized spasmodically and requires expenditure of energy

  20. Mechanical relaxation in glasses

    International Nuclear Information System (INIS)

    Hiki, Y.

    2004-01-01

    The basic properties of glasses and the characteristics of mechanical relaxation in glasses were briefly reviewed, and then our studies concerned were presented. Experimental methods adopted were viscosity, internal friction, ultrasonic attenuation, and Brillouin scattering measurements. The specimens used were several kinds of inorganic, organic, and metallic glasses. The measurements were mainly carried out from the room temperature up to the glass transition temperature, and the relaxation time was determined as a function of temperature. The 'double relaxation' composed of two Arrhenius-type relaxations was observed in many materials. In both relaxations, the 'compensation effect' showing a correlation of the pre-exponential factor and the activation energy was observed. These results were explained by considering the 'complex relaxation' due to cooperative motions of atoms or group of atoms. Values of activation energy near the glass transition determined by the various experimental methods were compared with each other

  1. Glass leaching performance

    International Nuclear Information System (INIS)

    Chick, L.A.; Turcotte, R.P.

    1983-05-01

    Current understanding of the leaching performance of high-level nuclear waste (HLW) glass is summarized. The empirical model of waste glass leaching behavior developed shows that at high water flow rates the glass leach rate is kinetically limited to a maximum value. At intermediate water flow rates, leaching is limited by the solution concentration of silica and decreases with decreasing water flow rates. Release of soluble elements is controlled by silica dissolution because silica forms the binding network of the glass. At low water flow rates, mass loss rates reach values controlled by formation rates of alteration minerals, or by diffusion of dissolution products through essentially stagnant water. The parameters reviewed with respect to their quantifiable influence on leaching behavior include temperature, pH, leachant composition, glass composition, thermal history, and radiation. Of these, temperature is most important since the rate of mass loss approximately doubles with each 10 0 C increase in dilute solutions. The pH has small effects within the 4 to 10 range. The chemical composition of the leachant is most important with regard to its influence on alteration product formation. Glass composition exhibits the largest effects at high flow rates where improved glasses leach from ten to thirty times slower than glass 76 to 68. The effects of the thermal history (devitrification) of the glass are not likely to be significant. Radiation effects are important primarily in that radiolysis can potentially drive pH values to less than 4. Radiation damage to the glass causes insignificant changes in leaching performance

  2. Sub-seafloor Microbial Colonization of Igneous Minerals and Glasses

    Science.gov (United States)

    Smith, A.; Popa, R.; Fisk, M.; Nielsen, M.; Wheat, G.; Jannasch, H.; Fisher, A.; Sievert, S.

    2008-12-01

    Understanding how subsurface microorganisms (MOs) contribute to mineral weathering and global element cycling requires an initial investigation into the differential colonization of minerals by distinct physiological types of MOs. We initiated a sub-seafloor experiment utilizing a variety of igneous minerals and glasses at IODP borehole site 1301A on the eastern flank of the Juan de Fuca Ridge. We selected twelve different igneous minerals and glasses and placed them in flow cell chambers at 278 meters below the seafloor in borehole 1301A. This horizon is approximately 15 meters into 3.5 million year old basalt basement, which underlies 263 meters of sediment. The samples were incubated in the borehole for four years and recovered in summer 2008. We report total colonization of the igneous minerals and glasses measured by cell density after DAPI staining and microscopic counting. To understand the relationship between MOs and mineral surfaces, we analyzed thin sections made from DAPI-treated minerals and glasses included in low- fluorescence resin.

  3. Magma Supply at the Arctic Gakkel Ridge: Constraints from Peridotites and Basalts

    Science.gov (United States)

    Sun, C.; Dick, H. J.; Hellebrand, E.; Snow, J. E.

    2015-12-01

    Crustal thickness in global ridge systems is widely believed to be nearly uniform (~7 km) at slow- and fast-spreading mid-ocean ridges, but appears significantly thinner (< ~4 km) at ultraslow-spreading ridges. At the slowest-spreading Arctic Gakkel Ridge, the crust becomes extremely thin (1.4 - 2.9 km; [1]). The thin crust at the Gakkel and other ultraslow-spreading ridges, has been attributed to lithosphere thickening, ancient mantle depletion, lower mantle temperature, ridge obliquity, and melt retention/focusing. To better understand the magma supply at ultraslow-spreading ridges, we examined melting dynamics by linking peridotites and basalts dredged along the Gakkel Ridge. We analyzed rare earth elements in clinopyroxene from 84 residual peridotites, and estimated melting parameters for individual samples through nonlinear least squares analyses. The degrees of melting show a large variation but mainly center at around 7% assuming a somewhat arbitrary but widely used depleted MORB mantle starting composition. Thermobarometry on published primitive basaltic glasses from [2] indicates that the mantle potential temperature at the Gakkel Ridge is ~50°C cooler than that at the East Pacific Rise. The ridge-scale low-degree melting and lower mantle potential temperature place the final depth of melting at ~30 km and a melt thickness of 1.0 or 2.9 km for a triangular or trapezoidal melting regime, respectively. The final melting depth is consistent with excess conductive cooling and lithosphere thickening suggested by geodynamic models, while the estimated melt thickness is comparable to the seismic crust (1.4 - 2.9 km; [1]). The general agreement among geochemical analyses, seismic measurements, and geodynamic models supports that lower mantle potential temperature and thick lithosphere determine the ridge-scale low-degree melting and thin crust at the Gakkel Ridge, while melt retention/focusing and excess ancient mantle depletion are perhaps locally important at

  4. The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian)

    OpenAIRE

    Daniela Ogrean

    2001-01-01

    The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes) indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Tim...

  5. Methods of simulating low redox potential (Eh) for a basalt repository

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1983-01-01

    Basalt groundwaters have inherently low redox potentials, approximately -0.4V, which can be measured with platinum electrodes, but are difficult to reproduce during leaching experiments. In the presence of deionized water, crushed basalt reaches the measured Eh-pH values of a basalt repository. Other waste package components, such as iron, will interact with groundwater in different ways under oxic or anoxic conditions since the presence of any redox active solid will affect the groundwater Eh. 26 references, 4 figures

  6. Petrology of basalt and single-mineral fragments in the soil of the Sea of Fertility

    Science.gov (United States)

    Bence, A. E.; Holzwarth, W.; Papike, J. J.

    1974-01-01

    Basalt and single-mineral particles, ranging from 150 to 425 microns, from the Luna-16 sample are studied by electron microanalysis, X-ray fluorescence analysis, and petrographic techniques. Three basalt species of different structure are identified. The structure and composition of the individual minerals (in particular of pyroxenes) indicate that the basalts have crystallized under conditions similar to those established for Apollo-11 samples.

  7. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed

  8. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

  9. Thermal Conductivity of Foam Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    as thermal insulating material in building and chemical industry. The large volume of gas (porosity 90 – 95%) is the main reason of the low thermal conductivity of the foam glass. If gases with lower thermal conductivity compared to air are entrapped in the glass melt, the derived foam glass will contain...... only closed pores and its overall thermal conductivity will be much lower than that of the foam glass with open pores. In this work we have prepared foam glass using different types of recycled glasses and different kinds of foaming agents. This enabled the formation of foam glasses having gas cells...... with different gas compositions. The foam glasses were characterised concerning densities, open/closed porosity and crystallinity. We find out, through analytical calculations and experiments, how the thermal conductivity of foam glass depends on density, glass composition and gas composition. Certain glass...

  10. Nuclear waste repository in basalt: preconceptual design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation.

  11. Nuclear waste repository in basalt: preconceptual design guidelines

    International Nuclear Information System (INIS)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation

  12. Reclamation report, Basalt Waste Isolation Project, boreholes 1990

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.; Cadoret, N.A.

    1991-01-01

    The restoration of areas disturbed activities of the Basalt Waste Isolation Project (BWIP) has been undertaken by the US Department of Energy (DOE) in fulfillment of obligations and commitments made under the National Environmental Policy Act and the Nuclear Waste Policy Act. This restoration program comprises three separate projects: borehole reclamation, Near Surface Test Facility reclamation, and Exploratory Shaft Facility reclamation. Detailed descriptions of these reclamation projects may be found in a number of previous reports. This report describes the second phase of the reclamation program for the BWIP boreholes and analyzes its success relative to the reclamation objective. 6 refs., 14 figs., 13 tabs.

  13. Friction Joint Between Basalt-Reinforced Composite and Aluminum

    DEFF Research Database (Denmark)

    Costache, Andrei; Glejbøl, Kristian; Sivebæk, Ion Marius

    2015-01-01

    The purpose of this study was to anchor basalt-reinforced polymers in an aluminum grip using dry friction. Dry friction clamping is considered the optimal solution for post-mounting of load-bearing terminations on composite structures. A new test method is presented for characterizing...... the frictional load transfer behavior of the grip. To carry out the study, a custom-built test rig was used to examine the relation between pullout force and clamping force. The anchoring method was found to be successful. The paper presents details on the custom-built test rig, along with the use of digital...

  14. Environmental issue identification for the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    Carrell, D.J.; Jones, K.A.

    1980-04-01

    A preliminary evaluation of environmental issues is provided in this report. It contains summary of the thought process that was used during the area characterization studies for a geological repository for high-level radioactive wastes. Environmental issues are discussed separately for construction, operation, and long term isolation aspects of a repository in basalt. During construction the primary environmental concerns are public perception and water resources; intermediate concerns are air quality, ecosystems, physical resources, and cultural and social resources. During operation, the primary environmental issues concern the transport of radioactive materials and physical resources. Long term environmental issues envolve water resources and borehole plugging

  15. Final Reclamation Report: Basalt Waste Isolation Project exploratory shaft site

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.

    1990-06-01

    The restoration of areas disturbed by activities of the Basalt Waste Isolation Project (BWIP) constitutes a unique operation at the US Department of Energy's (DOE) Hanford Site, both from the standpoint of restoration objectives and the time frame for accomplishing these objectives. The BWIP reclamation program comprises three separate projects: borehole reclamation, Near Surface Test Facility (NSTF) reclamation, and Exploratory Shaft Facility (ESF) reclamation. The main focus of this report is on determining the success of the revegetation effort 1 year after work was completed. This report also provides a brief overview of the ESF reclamation program. 21 refs., 7 figs., 14 tabs.

  16. Sentinel Gap basalt reacted in a temperature gradient

    International Nuclear Information System (INIS)

    Charles, R.W.; Bayhurst, G.K.

    1982-01-01

    Six basalt prisms were reacted in a controlled temperature gradient hydrothermal circulation system for two months. The prisms are centered at 72, 119, 161, 209, 270, and 310 0 C. Total pressure is 1/3 kbar. All prisms show large weight loss: 5.5% to 14.9%. The matrix micropegmatite and natural nontronitic alteration readily reacts to clays at all temperatures. The first four prisms are coated with a Ca-smectite while the last two prisms are covered with discrete patches of K rich phengite and alkali feldspar. The clays may act as adsorbers of various ions

  17. Hydrologic bibliography of the Columbia River basalts in Washington

    International Nuclear Information System (INIS)

    Tanaka, H.H.; Wildrick, L.

    1978-07-01

    This bibliography is part of the hydrologic data compilation effort of the Columbia Plateau Hydrology Study, Rockwell Hanford Operations' Waste Isolation Program. It includes references on both surface and subsurface hydrology directly or indirectly related to the Washington State portion of the Columbia River basalts. A comprehensive, annotated bibliography of the Pasco Basin (including the Hanford site) hydrology has been prepared for Rockwell Hanford Operations under the Pasco Basin Hydrology Study. In order to avoid unnecessary duplication, no effort was made to include a complete list of bibliographic references on Hanford in this volume

  18. Geochemical characterization of oceanic basalts using artificial neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.

    discrete geochemical traits of the OFB by using certain characteristic elemental concentration of these basalts. In order to classify the OFB we considered one major oxide (K 2 O),seventrace(Sc,Rb,Sr,Y,Zr,Nband Ba,),sixrareearthelements(REE)(La...,Ce,Nd,Sm,Eu, and Yb) and seven elemental ratios (Zr/Nb, Y/Nb, Ba/ Nb, Zr/Y, Sm/Nd, La/Yb and Ce/Y). A reason for utilizing the above mentioned elements and their ratios is because these carry the geochemical signatures of the individual OFB type i.e., N-MORB, E...

  19. Primitive off-rift basalts from Iceland and Jan Mayen

    DEFF Research Database (Denmark)

    Debaille, Vinciane; Trønnes, Reidar G.; Brandon, Alan D.

    2009-01-01

    and appear to be contaminated at a shallow level. The 187Os/188Os ratios in the remaining lavas with >30 ppt Os (n = 17) range between 0.12117 and 0.13324. These values are surprisingly low for oceanic island basalts and include some samples that are less than putative present-day primitive upper mantle (PUM....... Material from the Iceland mantle plume likely migrates at depth until it reaches the tensional setting of the Jan Mayen Fracture Zone, where it undergoes low-degree partial melting. At a first-order, isotopic co-variations can be interpreted as broadly binary mixing curves between two primary end...

  20. Basalt fiber manufacturing technology and the possibility of its use in dentistry

    Science.gov (United States)

    Karavaeva, E.; Rogozhnikov, A.; Nikitin, V.; Cherepennikov, Yu; Lysakov, A.

    2015-11-01

    The article touches upon the technology of basalt fiber manufacturing and prospects of its use in dental practice. Two kinds of construction using basalt fiber have been proposed. The first one is a splinting construction for mobile teeth and the second one is the reinforced base for removable plate-denture. The work presents the results of the investigation of physical and mechanical properties of the constructions based on basalt fiber. It also describes the aspects of biomechanical modeling of such constructions in the ANSYS software package. The results of the investigation have proved that applying constructions using basalt fiber is highly promising for prosthetic dentistry practice.

  1. Sub-basalt imaging problems and the application of Artificial Neural Networks

    Science.gov (United States)

    Fitzgerald, Elaine M.; Bean, Christopher J.

    2001-12-01

    In many areas of the world, the presence of shallow high velocity, highly heterogeneous layers complicate seismic imaging of deeper reflectors. Of particular economic interest are areas where potentially hydrocarbon-bearing strata are obscured by layers of basalt. Basalt layers are highly reflective and heterogeneous. Using reflection seismic, top basalt is typified by a high-amplitude, coherent reflector with poor resolution of reflectors below the basalt, and even bottom basalt. Here, we present a new approach to the imaging problem using the pattern recognition abilities of a back-propagation Artificial Neural Network (ANN). ANNs are computational systems that attempt to mimic natural biological neural networks. They have the ability to recognize patterns and develop their own generalizations about a given data set. Back-propagation neural networks are trained on data sets for which the solution is known and tested on the data that are not previously presented to the ANN in order to validate the network result. We show that Artificial Neural Networks, due to their pattern recognition capabilities, can invert the medium statistics based on the seismic character. We produce statistically defined models involving a basalt analogous layer, and calculate full wavefield finite difference synthetic seismograms. We vary basalt layer thickness and source frequency to generate a synthetic model that produces seismic that is similar to real sub-basalt seismic, i.e. high amplitude top basalt reflector and the absence of base basalt and sub-basalt events. Using synthetic shot gathers, generated in a synthetic representation of the sub-basalt case, we can invert the velocity medium standard deviation by using an ANN. By inverting the velocity medium standard deviation, we successfully identified the transition from basalt to sub-basalt on the synthetic shot gathers. We also show that ANNs are capable of identifying the basalt to sub-basalt transition in the presence of

  2. Rb-Sr and Sm-Nd chronology and genealogy of mare basalts from the Sea of Tranquility

    Science.gov (United States)

    Papanastassiou, D. A.; Depaolo, D. J.; Wasserburg, G. J.

    1977-01-01

    Rb-Sr and Sm-Nd ages of two Apollo 11 mare basalts, high-K basalt 10072 and low-K basalt 10062, are reported. Rb-Sr, Sm-Nd, and Ar-40-Ar-39 ages are in good agreement and indicate an extensive time interval for filling of the Sea of Tranquility, presumably by thin lava flows, in agreement with similar observations for the Ocean of Storms. Initial Sr and Nd isotopic compositions on Apollo 11 basalts reveal at least two parent sources producing basalts. The Sm-Nd isotopic data demonstrate that low-K and high-Ti basalts from Apollo 11 and 17 derived from distinct reservoirs, while low-Ti Apollo 15 mare basalt sources have Sm/Nd similar to the sources of Apollo 11 basalts. Groupings of mare basalt based on Ti content and on isotopic data do not coincide.

  3. Bioactive glasses and glass-ceramics

    Directory of Open Access Journals (Sweden)

    de Aza, P. N.

    2007-04-01

    Full Text Available Since the late 1960´s, a great interest in the use of bioceramic materials for biomedical applications has been developed. In a previous paper, the authors reviewed crystalline bioceramic materials “sensus stricto”, it is to say, those ceramic materials, constituted for non-metallic inorganic compounds, crystallines and consolidates by thermal treatment of powders at high temperature. In the present review, the authors deal with those called bioactive glasses and glassceramics. Although all of them are also obtained by thermal treatment at high temperature, the first are amorphous and the second are obtained by devitrification of a glass, although the vitreous phase normally prevails on the crystalline phases. After an introduction to the concept of bioactive materials, a short historical review of the bioactive glasses development is made. Its preparation, reactivity in physiological media, mechanism of bonding to living tissues and mechanical strength of the bone-implant interface is also reported. Next, the concept of glass-ceramic and the way of its preparation are exposed. The composition, physicochemical properties and biological behaviour of the principal types of bioactive glasses and glass-ceramic materials: Bioglass®, Ceravital®, Cerabone®, Ilmaplant® and Bioverit® are also reviewed. Finally, a short review on the bioactive-glass coatings and bioactive-composites and most common uses of bioactive-glasses and glass-ceramics are carried out too.

    Desde finales de los años sesenta, se ha despertado un gran interés por el uso de los materiales biocerámicos para aplicaciones biomédicas. En un trabajo previo, los autores hicieron una revisión de los denominados materiales biocerámicos cristalinos en sentido estricto, es decir, de aquellos materiales, constituidos por compuestos inorgánicos no metálicos, cristalinos y consolidados mediante tratamientos térmicos a altas temperaturas. En el presente trabajo, los autores

  4. A Picture behind Glass

    Directory of Open Access Journals (Sweden)

    Poprzęcka, Maria

    2010-04-01

    Full Text Available The paper considers the singular situation of reception occasioned by a painting shielded with a reflective pane of glass. The reflections in the glass dramatically break the cohesion of the painting and bring about distracting – although sometimes intriguing – surprises. The glass is an iconoclastic intrusion, an infection of the artistic order by an invading disorder and transient immediacy, which however can be very attractive visually. The accidental obliterates the significant. "The truth of art" is confronted here with a delusive phantom. Not only two entirely different visual effects are mixed here, but also different ontological and axiological spheres.

  5. Orbital glass in HTSC

    International Nuclear Information System (INIS)

    Kusmartsev, F.V.

    1992-10-01

    The physical reasons why the orbital glass may exist in granular high-temperature superconductors and the existing experimental data appeared recently are discussed. The orbital glass is characterized by the coexistence of the orbital paramagnetic state with the superconducting state and occurs at small magnetic fields H c0 c1 . The transition in orbital glass arises at the critical field H c0 which is inversely proportional to the surface cross-area S of an average grain. In connection with theoretical predictions the possible experiments are proposed. (author). 10 refs

  6. Spin glasses (II)

    International Nuclear Information System (INIS)

    Fischer, K.H.

    1985-01-01

    Experimental results of spin glass studies are reviewed and related to existing theories. Investigations of spin glasses are concentrated on atomic structure, metallurgical treatment, and high-temperature susceptibility of alloys, on magnetic properties at low temperature and near the freezing temperature, on anisotropy behaviour measured by ESR, NMR and torque, on specific heat, Moessbauer effect, neutron scattering and muon-spin depolarization experiments, ultrasound and transport properties. Some new theories of spin glasses are discussed which have been developed since Part I appeared

  7. Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Bennecke, William M. [Boise State Univ., ID (United States)

    1996-10-01

    A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well.

  8. Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

    International Nuclear Information System (INIS)

    Bennecke, W.M.

    1996-10-01

    A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well

  9. Quality of the ground water in basalt of the Columbia River group, Washington, Oregon, and Idaho

    Science.gov (United States)

    Newcomb, Reuben Clair

    1972-01-01

    The ground water within the 50,000-square-mile area of the layered basalt of the Columbia River Group is a generally uniform bicarbonate water having calcium and sodium in nearly equal amounts as the principal cations. water contains a relatively large amount of silica. The 525 chemical analyses indicate that the prevalent ground water is of two related kinds--a calcium and a sodium water. The sodium water is more common beneath the floors of the main synclinal valleys; the calcium water, elsewhere. In addition to the prevalent type, five special types form a small part of the ground water; four of these are natural and one is artificial. The four natural special types are: (1) calcium sodium chloride waters that rise from underlying sedimentary rocks west of the Cascade Range, (2) mineralized water at or near warm or hot springs, (3) water having unusual ion concentrations, especially of chloride, near sedimentary rocks intercalated at the edges of the basalt, and (4) more mineralized water near one locality of excess carbon dioxide. The one artificial kind of special ground water has resulted from unintentional artificial recharge incidental to irrigation in parts of central Washington. The solids dissolved in the ground water have been picked up on the surface, within the overburden, and from minerals and glasses within the basalt. Evidence for the removal of ions from solution is confined to calcium and magnesium, only small amounts of which are present in some of the sodium-rich water. Minor constituents, such as the heavy metals, alkali metals, and alkali earths, occur in the ground water in trace, or small, amounts. The natural radioactivity of the ground waters is very low. Except for a few of the saline calcium sodium chloride waters and a few occurrences of excessive nitrate, the ground water generally meets the common standards of water good for most ordinary uses, but some of it can be improved by treatment. The water is clear and colorless and has a

  10. Fun with Singing Wine Glasses

    Science.gov (United States)

    Boone, Christine; Galloway, Melodie; Ruiz, Michael J.

    2018-01-01

    A fun activity is presented using singing wine glasses for introductory physics students. Students tune a white wine glass and a red wine glass to as many semitones as possible by filling the glasses with the appropriate amounts of water. A smart phone app is used to measure the frequencies of equal-temperament tones. Then plots of frequency…

  11. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  12. Super ionic conductive glass

    Science.gov (United States)

    Susman, S.; Volin, K.J.

    Described is an ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A/sub 1 + x/D/sub 2-x/3/Si/sub x/P/sub 3 - x/O/sub 12 - 2x/3/, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  13. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    The use of glass as a load carrying material in structural elements is rarely seen even though glass is a popular material for many architects. This is owed to the unreliable and low tensile strength, which is due to surface flaws and high brittleness of the material. These properties lead...... to breakage without any warning or ductility, which can be catastrophic if no precautions are taken. One aspect of this issue is treated here by looking at the possibility of mechanically reinforcing glass beams in order to obtain ductile failure for such a structural component. A mechanically reinforced...... presented. The experiments show that it is possible to obtain a very ductile structural behavior using the right amount of reinforcement. A Finite Element Model including - in a simple manner - the effects of cracking of glass is presented. Based on a comparison between experimental and model results...

  14. Waste glass weathering

    International Nuclear Information System (INIS)

    Bates, J.K.; Buck, E.C.

    1994-01-01

    The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared to release under standard leaching conditions. While the comparison between the release under weathering and leaching conditions is not exact, due to variability of reaction in humid air, evidence is presented of radionuclide release under a variety of conditions. These results suggest that both the amount and form of radionuclide release can be affected by the weathering of glass

  15. Phosphate glasses, containing nitrogen

    International Nuclear Information System (INIS)

    Lisitsyna, E.A.; Khalilev, V.D.; Koryavin, A.A.; Goncharova, L.N.

    1987-01-01

    Possibilities of nitrogen-containing glass synthesis by the introduction into the charge of ammonium salts, as well as aluminium nitride, are studied. Zinc alumoyttrium phosphate glass (mol. %) Zn(PO 3 ) 2 - 4O, Al(PO 3 ) 3 - 3O, Y(PO 3 ) 3 -3O is suggested as a matrix. It is shown that the effect of amide and imide groups on the properties of the glass is less noticeable than the effect of nitride groups. Direct introduction of nitride constituent was realized using AlN, but aluminium introduction was taken into account so that the oxide was subtracted. The attempt to introduce more than 2.5 mass % of nitrogen into initial matrix by aluminium nitride has failed due to repeated restoration of glass with amorphous phosphorus isolation

  16. Characterization and recognition of intraflow structures, Grande Ronde Basalt

    International Nuclear Information System (INIS)

    Long, P.E.

    1978-09-01

    This investigation was carried out as part of a feasibility study for long-term storage of nuclear waste at depth in the Pasco Basin. Three general types of intraflow structures were found at Sentinel Gap: flows with stubby, irregular columns that lack a well-developed entablature; flows consisting of multiple tiers of largely entablature-type columns; and flows with a well-developed colonnade and entablature showing a sharp break between the two. Certain features occur locally in all three types of intraflow structures: variations in fracture morphology, primary platey fracture zones, pillow-palagonite zones, and tectonically induced zones of closely spaced fractures. Fractures in each of the three types of flows were logged both at the surface and in core from Core Hole DH-5, and petrographic textures of basalt sampled from surface exposures were examined. The textures of the basalt correlate with the intraflow structures and provide a technique for identifying flows as to their general type of intraflow structure, locating internal contacts between intraflow structures and possibly estimating fracture density within flows. Fracture logging, on the other hand, does not accurately delimit intraflow structures

  17. Fungal colonies in open fractures of subseafloor basalt

    Science.gov (United States)

    Ivarsson, Magnus; Bengtson, Stefan; Skogby, Henrik; Belivanova, Veneta; Marone, Federica

    2013-08-01

    The deep subseafloor crust is one of the few great frontiers of unknown biology on Earth and, still today, the notion of the deep biosphere is commonly based on the fossil record. Interpretation of palaeobiological information is thus central in the exploration of this hidden biosphere and, for each new discovery, criteria used to establish biogenicity are challenged and need careful consideration. In this paper networks of fossilized filamentous structures are for the first time described in open fractures of subseafloor basalts collected at the Emperor Seamounts, Pacific Ocean. These structures have been investigated with optical microscopy, environmental scanning electron microscope, energy dispersive spectrometer, X-ray powder diffraction as well as synchrotron-radiation X-ray tomographic microscopy, and interpreted as fossilized fungal mycelia. Morphological features such as hyphae, yeast-like growth and sclerotia were observed. The fossilized fungi are mineralized by montmorillonite, a process that probably began while the fungi were alive. It seems plausible that the fungi produced mucilaginous polysaccharides and/or extracellular polymeric substances that attracted minerals or clay particles, resulting in complete fossilization by montmorillonite. The findings are in agreement with previous observations of fossilized fungi in subseafloor basalts and establish fungi as regular inhabitants of such settings. They further show that fossilized microorganisms are not restricted to pore spaces filled by secondary mineralizations but can be found in open pore spaces as well. This challenges standard protocols for establishing biogenicity and calls for extra care in data interpretation.

  18. The Disruption of Tephra Fall Deposits by Basaltic Lava Flows

    Science.gov (United States)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2010-12-01

    Complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents of the Roza Member in the Columbia River Basalt Province, (CRBP), USA, illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter tephra fall deposits. Thin pahoehoe lobes and sheet lobes occur intercalated with tephra deposits and provide evidence for synchronous effusive and explosive activity. Tephra that accumulated on the tops of inflating pahoehoe flows became disrupted by tumuli, which dissected the overlying sheet into a series of mounds. During inflation of subjacent tumuli tephra percolated down into the clefts and rubble at the top of the lava, and in some cases came into contact with lava hot enough to thermally alter it. Lava breakouts from the tumuli intruded up through the overlying tephra deposit and fed pahoehoe flows that spread across the surface of the aggrading tephra fall deposit. Non-welded scoria fall deposits were compacted and welded to a depth of ~50 cm underneath thick sheet lobes. These processes, deduced from the field relationships, have resulted in considerable stratigraphic complexity in proximal regions. We also demonstrate that, when the advance of lava and the fallout of tephra are synchronous, the contacts of some tephra sheets can be diachronous across their extent. The net effect is to reduce the usefulness of pyroclastic deposits in reconstructing eruption dynamics.

  19. Baseline LAW Glass Formulation Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A. [USDOE Office of River Protection, Richland, WA (United States); Mooers, Cavin [The Catholic University of America, Washington, DC (United States). Vitreous State Lab.; Bazemore, Gina [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Pegg, Ian L. [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Hight, Kenneth [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Lai, Shan Tao [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Buechele, Andrew [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Rielley, Elizabeth [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Gan, Hao [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Muller, Isabelle S. [The Catholic University of America, Washington, DC (United States). Vitreous State Lab; Cecil, Richard [The Catholic University of America, Washington, DC (United States). Vitreous State Lab

    2013-06-13

    The major objective of the baseline glass formulation work was to develop and select glass formulations that are compliant with contractual and processing requirements for each of the LAW waste streams. Other objectives of the work included preparation and characterization of glasses with respect to the properties of interest, optimization of sulfate loading in the glasses, evaluation of ability to achieve waste loading limits, testing to demonstrate compatibility of glass melts with melter materials of construction, development of glass formulations to support ILAW qualification activities, and identification of glass formulation issues with respect to contract specifications and processing requirements.

  20. Reaction of water with a simulated high-level nuclear waste glass at 3000C, 300 bars

    International Nuclear Information System (INIS)

    McCarthy, G.J.; Scheetz, B.E.; Komarneni, S.; Smith, D.K.

    1978-01-01

    The hydrothermal stability of high-level nuclear wastes is an important consideration in establishing waste form acceptance criteria for a geological repository in basalt. A detailed examination of the stability of a typical simulated high-level waste glass and pressurized water at 300 0 C in a closed system has shown that extensive reaction occurred within a few weeks. The water acted first as a catalyst-solvent in devitrification of the glass and in dissolution, transport, and recrystallization of some of its constituents, and, second, as a reactant in forming hydrated and hydroxylated phases. This reaction with water resulted in the conversion of a solid shard of glass into a fragmented and partially dispersed mass of crystalline and noncrystalline material plus dissolved species within two weeks. The major crystalline reaction products were found to be analogs of naturally occurring minerals: (Cs,Na,Rb) 2 (UO 2 ) 2 .(Si 2 O 5 ) 3 .4H 2 O (weeksite) and a series of pyroxene-structure phases, (Na,Ca) (Fe,Zn,Ti)Si 2 O 6 (acmite, acmite--augites). Weeksite, however, is not expected to have long-term stability in the basalt environment. Much of the Na and Mo, and almost all of the B, in the original glass was identified in the product solutions. Of the elements or analogs of long-lived, hazardous radionuclides studied in this work, only Cs was observed in these solutions in substantial amounts. Although the comparatively rapid and extensive reactions at 300 0 C would appear to require that an acceptable glass would have low waste and heat loading, it is suggested that there is good potential for favorable glass--basalt--water hydrothermal interactions. Favorable interactions would mean that, in the event of a hydrothermal incident, the interaction products would be more stable than the original waste form and would remain in the immediate repository

  1. Wastes based glasses and glass-ceramics

    Directory of Open Access Journals (Sweden)

    Barbieri, L.

    2001-12-01

    Full Text Available Actually, the inertization, recovery and valorisation of the wastes coming from municipal and industrial processes are the most important goals from the environmental and economical point of view. An alternative technology capable to overcome the problem of the dishomogeneity of the raw material chemical composition is the vitrification process that is able to increase the homogeneity and the constancy of the chemical composition of the system and to modulate the properties in order to address the reutilization of the waste. Moreover, the glasses obtained subjected to different controlled thermal treatments, can be transformed in semy-cristalline material (named glass-ceramics with improved properties with respect to the parent amorphous materials. In this review the tailoring, preparation and characterization of glasses and glass-ceramics obtained starting from municipal incinerator grate ash, coal and steel fly ashes and glass cullet are described.

    Realmente la inertización, recuperación y valorización de residuos que proceden de los procesos de incineración de residuos municipales y de residuos industriales son metas importantes desde el punto de vista ambiental y económico. Una tecnología alternativa capaz de superar el problema de la heterogeneidad de la composición química de los materiales de partida es el proceso de la vitrificación que es capaz de aumentar la homogeneidad y la constancia de la composición química del sistema y modular las propiedades a fin de la reutilización del residuo. En este artículo se presentan los resultados de vitrificación en que los vidrios fueron sometidos a tratamientos térmicos controlados diferentes, de manera que se transforman en materiales semicristalinos (también denominados vitrocerámicos con mejores propiedades respecto a los materiales amorfos originales. En esta revisión se muestra el diseño, preparación y caracterización de vidrios y vitrocerámicos partiendo de

  2. Discovery of Naturally Etched Fission Tracks and Alpha-Recoil Tracks in Submarine Glasses: Reevaluation of a Putative Biosignature for Earth and Mars

    Directory of Open Access Journals (Sweden)

    Jason E. French

    2016-01-01

    Full Text Available Over the last two decades, conspicuously “biogenic-looking” corrosion microtextures have been found to occur globally within volcanic glass of the in situ oceanic crust, ophiolites, and greenstone belts dating back to ~3.5 Ga. These so-called “tubular” and “granular” microtextures are widely interpreted to represent bona fide microbial trace fossils; however, possible nonbiological origins for these complex alteration microtextures have yet to be explored. Here, we reevaluate the origin of these enigmatic microtextures from a strictly nonbiological standpoint, using a case study on submarine glasses from the western North Atlantic Ocean (DSDP 418A. By combining petrographic and SEM observations of corrosion microtextures at the glass-palagonite interface, considerations of the tectonic setting, measurement of U and Th concentrations of fresh basaltic glass by ICP-MS, and theoretical modelling of the present-day distribution of radiation damage in basaltic glass caused by radioactive decay of U and Th, we reinterpret these enigmatic microtextures as the end product of the preferential corrosion/dissolution of radiation damage (alpha-recoil tracks and fission tracks in the glass by seawater, possibly combined with pressure solution etch-tunnelling. Our findings have important implications for geomicrobiology, astrobiological exploration of Mars, and understanding of the long-term breakdown of nuclear waste glass.

  3. Glass microsphere lubrication

    Science.gov (United States)

    Geiger, Michelle; Goode, Henry; Ohanlon, Sean; Pieloch, Stuart; Sorrells, Cindy; Willette, Chris

    1991-01-01

    The harsh lunar environment eliminated the consideration of most lubricants used on earth. Considering that the majority of the surface of the moon consists of sand, the elements that make up this mixture were analyzed. According to previous space missions, a large portion of the moon's surface is made up of fine grained crystalline rock, about 0.02 to 0.05 mm in size. These fine grained particles can be divided into four groups: lunar rock fragments, glasses, agglutinates (rock particles, crystals, or glasses), and fragments of meteorite material (rare). Analysis of the soil obtained from the missions has given chemical compositions of its materials. It is about 53 to 63 percent oxygen, 16 to 22 percent silicon, 10 to 16 percent sulfur, 5 to 9 percent aluminum, and has lesser amounts of magnesium, carbon, and sodium. To be self-supporting, the lubricant must utilize one or more of the above elements. Considering that the element must be easy to extract and readily manipulated, silicon or glass was the most logical choice. Being a ceramic, glass has a high strength and excellent resistance to temperature. The glass would also not contaminate the environment as it comes directly from it. If sand entered a bearing lubricated with grease, the lubricant would eventually fail and the shaft would bind, causing damage to the system. In a bearing lubricated with a solid glass lubricant, sand would be ground up and have little effect on the system. The next issue was what shape to form the glass in. Solid glass spheres was the only logical choice. The strength of the glass and its endurance would be optimal in this form. To behave as an effective lubricant, the diameter of the spheres would have to be very small, on the order of hundreds of microns or less. This would allow smaller clearances between the bearing and the shaft, and less material would be needed. The production of glass microspheres was divided into two parts, production and sorting. Production includes the

  4. Crystal Recycling in the Steady-State System of the Active Stromboli Volcano: a 2.5 ka Story Inferred from In-Situ Sr-ISOTOPE and Trace-Element Data

    Science.gov (United States)

    Francalanci, L.; Avanzinelli, R.; Nardini, I.; Tiepolo, M.; Davidson, J. P.; Vannucci, R.

    2011-12-01

    On 28 December 2002, the persistent moderate explosive activity of the Stromboli volcano (Aeolian Islands, Italy) was broken by an effusive event lasting about seven months. A more violent explosion (paroxysm) occurred on 5 April 2003. Two magma types were erupted, namely a volatile-poor and highly-porphyritic magma (HP-magma) poured out as scoria or lava and a volatile-rich, phenocryst-poor magma (LP-magma) found as pumice. LP-magma differs from the HP-magma also for its slightly less evolved chemistry, the groundmass composition and the lower Sr-isotope ratios. In-situ Sr-isotope data by microdrilling, coupled with major and trace element analyses have been performed on plagioclase and clinopyroxene from seven samples collected during the 2002-2003 eruptive crisis. Micro-Sr isotope data show the presence of zoned minerals in strong isotope disequilibrium, as previously found in products erupted in 1984, 1985 and 1996 AD, with 87Sr/86Sr values generally decreasing from cores to rims of minerals. Only some outer-rims testify for equilibrium with the host groundmass. The internal mineral zones with high Sr-isotope ratios are interpreted as "antecrysts", crystallised during the previous activity and recycled in the present-day system since the opening shoshonitic activity of the Recent Period, which occurred at about 2.5 ka ago. This result has inferences for the dynamics of the present-day plumbing system of Stromboli at intermediate pressure (about 2-3 km depth), allowing us to propose a model whereby an HP-magma reservoir is directly interconnected at the bottom with a cumulate crystal much reservoir. Efficient mixing between residing HP- and input LP-magmas can occur in this reservoir, due to more similar rheological characteristics of the two magmas than in the conduit, where crystallization is enhanced by degassing. Antecrysts (and possibly melts) re-enter in the HP-magma reservoir both from the bottom, recycled by ascending LP-magmas crossing the crystal mush

  5. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D; Bradley Pickenheim, B

    2008-11-24

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  6. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    International Nuclear Information System (INIS)

    Adamson, D.; Pickenheim, Bradley

    2008-01-01

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  7. Heck and Heckle Seamounts, northeast Pacific Ocean: High extrusion rates of primitive and highly depleted mid-ocean ridge basalt on off-ridge seamounts

    Science.gov (United States)

    Leybourne, M. I.; van Wagoner, N. A.

    1991-09-01

    We analyzed, petrographically and chemically, basalt from eight dredge hauls from the Heck and Heckle seamounts, northeast Pacific Ocean. Major elements were determined for mineral, glass, and whole rock samples, and trace and rare earth elements were determined for glass and whole rock samples. The dredge hauls included hyaloclastites and fragments from sheet flows and pillows. The clinkery fragments are interpreted to be deformed sheet flow tops, characteristic of high effusion rates. The hyaloclastites recovered are reworked deposits, as indicated by the wide compositional range of the glass shards, abundance of clay and calcite matrix, and bedding. Most rocks are aphyric, but the analyzed plagioclase and olivine phenocrysts and microcrysts are equilibrium compositions and show minor compositional zonation (up to 7.5% An, chains have a limited range of incompatible element ratios, whereas the adjacent West Valley Segment of the Juan de Fuca Ridge is highly heterogeneous. In contrast, lavas from the East Pacific near-ridge seamounts exhibit a wider range of incompatible element ratios than do the adjacent East Pacific Rise basalts. On the West Valley Segment, magma supply is less robust associated with lower spreading rates compared to the East Pacific Rise at 10°N. In contrast, at fast spreading centers robust melting produces a mixed mantle signature in axial lavas, while suppressed melting at the seamounts reveals the heterogeneities. We suggest that at some spreading ridges, more fertile portions of the mantle are preferentially melted such that the outwelled portions of the mantle tapped by the seamounts are more depleted.

  8. Reaction microtextures in entrapped xenoliths in alkali basalts from the Deccan large igneous province, India: Implications to the origin and evolution

    Science.gov (United States)

    Chattopadhaya, Soumi; Ghosh, Biswajit; Morishita, Tomoaki; Nandy, Sandip; Tamura, Akihiro; Bandyopadhyay, Debaditya

    2017-05-01

    The onset of the end-Mesozoic continental rift magmatism in the Deccan volcanic province (DVP), India is marked by alkali magmatism. Lithospheric fragments occurring as xenoliths/xenocrysts entrapped in alkaline basalts from the Kutch area of the DVP preserve reaction microtextures giving an insight into the processes linked to their origin. We interpret the flower texture, an aggregate of systematically arranged tiny diopside crystals, as a product of interactions between ghost quartz xenocrysts with alkaline silica-undersaturated melt. The mantle xenoliths, mostly represented by spinel lherzolites and wehrlites have been infiltrated by melt. The orthopyroxenes present at the margin of the xenoliths or in contact with infiltrated melt exhibit a coronal texture composed of olivine, clinopyroxene and glass around them. The compositions of cores of primary olivines at places retain mantle signatures, whereas, the margins are reequilibrated. Secondary olivines and clinopyroxenes at reaction coronas have a wide range of compositions. Primary clinopyroxenes and spinels in close vicinity to the orthopyroxene corona display a sieve texture defined by clear inclusion-free cores and a compositionally different spongy altered rim with worm-shaped or bubbly inclusions dominantly filled with glass. The rims are marked with higher Ca, Mg-lower Na, Al for clinopyroxenes and higher Ti, Cr-lower Mg, Al for spinels in comparison to their cores. The coronal texture around orthopyroxenes and spongy texture in clinopyroxenes and spinels in these xenoliths are interpreted to be genetically linked. The silicate glasses in the xenoliths show large compositional variations and they are much more siliceous and alkali-rich in comparison to the host basalts. The petrography and mineral chemistry suggest host magma-peridotite interaction during or after the entrainment of the xenoliths, corroborating well with the experimental findings.

  9. Intracanyon basalt lavas of the Debed River (northern Armenia), part of a Pliocene-Pleistocene continental flood basalt province in the South Caucasus

    Science.gov (United States)

    Sheth, Hetu; Meliksetian, Khachatur; Gevorgyan, Hripsime; Israyelyan, Arsen; Navasardyan, Gevorg

    2015-03-01

    Late Pliocene to Early Pleistocene (~ 3.25-2.05 Ma), 200-400 m thick basalt lavas outcrop in the South Caucasus region, including the Kars-Erzurum Plateau (northeastern Turkey), the Javakheti Plateau (Georgia-Armenia), and the Lori Plateau (northern Armenia). These fissure-fed, rapidly erupted fluid lavas filled pre-existing river valleys over many tens of kilometres. The basalts exposed in the Debed River canyon, northern Armenia, are ~ 200 m thick and of three morphological types: (1) basal pillow basalts and hyaloclastites, overlain by (2) columnar-jointed pahoehoe sheet flows, in turn overlain by (3) slabby pahoehoe and rubbly pahoehoe flows. The lower and middle lavas show evidence for damming of river drainage, like many lavas of the Columbia River flood basalt province, Scotland, Ireland, and Iceland. There is also evidence for syn-volcanic faulting of the early lavas. Related basalts also outcrop in the Gegham Uplands and the Hrazdan River basin in Armenia. This 3.25-2.05 Ma South Caucasus basalt province, covering parts of Turkey, Georgia and Armenia, has an estimated areal extent of ~ 15,000 km2 and volume of ~ 2250 km3. Because its main geological features are remarkably like those of many continental flood basalt (CFB) provinces, we consider it a true, albeit small, CFB province. It is the smallest and youngest CFB in the world. An analogue closely similar in major features is the Late Miocene Altos de Jalisco CFB province in the western Trans-Mexican Volcanic Belt. Both provinces formed during lithospheric pull-apart and transtensional faulting. Their broader significance is in showing flood basalt size distribution to be a continuum without natural breaks, with implications for geodynamic models.

  10. Post-Columbia River Basalt Group stratigraphy and map compilation of the Columbia Plateau, Oregon

    International Nuclear Information System (INIS)

    Farooqui, S.M.; Bunker, R.C.; Thoms, R.E.; Clayton, D.C.; Bela, J.L.

    1981-01-01

    This report presents the results of reconnaissance mapping of sedimentary deposits and volcanic rocks overlying the Columbia River Basalt. The project area covers parts of the Dalles, Pendleton, Grangeville, Baker, Canyon City, and Bend. The mapping was done to provide stratigraphic data on the sedimentary deposits and volcanic rocks overlying the Columbia River Basalt Group. 160 refs., 16 figs., 1 tab

  11. Importance of plagioclase morphology and composition in magmagenesis of the Carlsberg Ridge basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Banerjee, R.

    The morphology and chemical composition of more than 200 plagioclase crystals in the Carlsberg Ridge basalts (3~'35' and 3~'41'N) in relation to the magmagenesis of the basalts is examined. The results indicate that the different morphotypes...

  12. From mantle roots to surface eruptions: Cenozoic and Mesozoic continental basaltic magmatism

    Czech Academy of Sciences Publication Activity Database

    Kämpf, H.; Németh, K.; Puziewicz, J.; Mrlina, Jan; Geissler, W.H.

    2015-01-01

    Roč. 104, č. 8 (2015), s. 1909-1912 ISSN 1437-3254 Institutional support: RVO:67985530 Keywords : continental basaltic volcanism * BASALT 2013 conference * Cenozoic * Mesozoic Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.133, year: 2015

  13. Prokaryotic diversity, distribution, and insights into their role in biogeochemical cycling in marine basalts

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Olivia U.; Di Meo-Savoie, Carol A.; Van Nostrand, Joy D.; Zhou, Jizhong; Fisk, Martin R.; Giovannoni, Stephen J.

    2008-09-30

    We used molecular techniques to analyze basalts of varying ages that were collected from the East Pacific Rise, 9 oN, from the rift axis of the Juan de Fuca Ridge, and from neighboring seamounts. Cluster analysis of 16S rDNA Terminal Restriction Fragment Polymorphism data revealed that basalt endoliths are distinct from seawater and that communities clustered, to some degree, based on the age of the host rock. This age-based clustering suggests that alteration processes may affect community structure. Cloning and sequencing of bacterial and archaeal 16S rRNA genes revealed twelve different phyla and sub-phyla associated with basalts. These include the Gemmatimonadetes, Nitrospirae, the candidate phylum SBR1093 in the c, andin the Archaea Marine Benthic Group B, none of which have been previously reported in basalts. We delineated novel ocean crust clades in the gamma-Proteobacteria, Planctomycetes, and Actinobacteria that are composed entirely of basalt associated microflora, and may represent basalt ecotypes. Finally, microarray analysis of functional genes in basalt revealed that genes coding for previously unreported processes such as carbon fixation, methane-oxidation, methanogenesis, and nitrogen fixation are present, suggesting that basalts harbor previously unrecognized metabolic diversity. These novel processes could exert a profound influence on ocean chemistry.

  14. Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.; Hazra, S.

    ferrobasaltic composition. The basalts have high incompatible elements (Zr 63-228 ppm; Nb approx. 1-5 ppm; Ba approx. 15-78 ppm; La approx. 3-16 ppm), a similar U/Pb (0.02-0.4) ratio as the normal mid-oceanic basalt (0.16 plus or minus 0.07) but the Ba/Nb (12...

  15. Experimental investigation of the reaction between corundum xenocrysts and alkaline basaltic host magma: Constraints on magma residence times of basalt-hosted sapphires

    Science.gov (United States)

    Baldwin, L. C.; Ballhaus, C.

    2018-03-01

    Megacrystic sapphires (Fe-Ti-rich corundum) of up to 5 cm in size are well known from alkaline mafic rocks from intra-continental rift-related magmatic fields. There is no doubt that these sapphires represent xenocrysts that were trapped from their original lithology by ascending basaltic magmas carrying them to the Earth's surface. Most studies about basalt-hosted sapphires address the question about the origin of the sapphires, but there is hardly any information available about the time the sapphires resided inside the carrier melt. Sapphires are in reaction relationship with basalt and produce spinel coronas at the sapphire-basalt interface, spatially separating the mutually incompatible phases from one another. Assuming isothermal and isobaric conditions of spinel rim formation, the rim-thickness should be a function of the reaction time with the basaltic melt. In this paper, we report time-series experiments aimed at investigating the kinetics of spinel rim formation due to igneous corrosion of corundum. Therefore, we reacted corundum fragments with alkaline basalt powder at 1250 °C and 1GPa, using a Piston Cylinder Apparatus. The width of the spinel rim was used to estimate a residence time. Extrapolating the experimentally derived reaction rates to the thickness of natural spinel rims as described from the Siebengebirge Volcanic Field, Germany, and from Changle, China, we estimated residence times in the order of a few weeks to months.

  16. Basaltic scoria fallout deposits from Ambrym volcano (Vanuatu archipelago): Textural and geochemical evidence of plinian eruptive styles

    Science.gov (United States)

    Balcone-Boissard, H.; Boudon, G.; Poulain, P.

    2017-12-01

    Plinian eruptions are among the most threatening volcanic hazard responsible of gas and solid particles release into atmosphere leading to potential damages at various spatial and time scales. Such explosive activity generally involves differentiated magmas, silica-rich enough to behave as viscous media and volatile-rich enough to generate significant overpressure in ascending magma. In some rare cases, Plinian eruptions can occur with more basic magmas as basalts. Few eruptions are now recognized on Earth, on Etna (122 BC), Masaya (Fontana) or Tarawera (1886). On Ambrym volcano (Vanuatu), the caldera formation was the result of several large eruptions including some Plinian events dated around 2000 yr. BP. By applying joint textural and geochemical investigations of a representative stratigraphic section of one of these eruptions we present new arguments to discuss the origin of such explosivity for basic magma. To achieve this goal we establish a degassing budget (H2O, CO2, SO2, F, Cl) through the petrological investigation by comparing melt inclusion and residual glass. We compare these results to those of quantitative textural description of pumice clasts through SEM images treated using Image J software, thus linking textural and geochemical arguments. We thus highlight that a low volatile content is not responsible of the overpressure leading to explosivity. Textural characteristics evidence vesicle organisation and low microlite content close that described for Plinian eruption involving differentiated melt. Degassing processes occur following a closed-system degassing evolution well correlated with textural parameters. By comparison to deposits of other basaltic Plinian eruptions, we show that for 122 BC eruption of Mt Etna, textural signature is diverse although we also evidence closed-system degassing processes. This study also permits to confirm that Ambrym is a valuable contributor to halogen release into the atmosphere at a time of reflexion on

  17. Effect of Moisture Absorption Behavior on Mechanical Properties of Basalt Fibre Reinforced Polymer Matrix Composites

    Directory of Open Access Journals (Sweden)

    Amuthakkannan Pandian

    2014-01-01

    Full Text Available The study of mechanical properties of fibre reinforced polymeric materials under different environmental conditions is much important. This is because materials with superior ageing resistance can be satisfactorily durable. Moisture effects in fibre reinforced plastic composites have been widely studied. Basalt fibre reinforced unsaturated polyester resin composites were subjected to water immersion tests using both sea and normal water in order to study the effects of water absorption behavior on mechanical properties. Composites specimens containing woven basalt, short basalt, and alkaline and acid treated basalt fibres were prepared. Water absorption tests were conducted by immersing specimens in water at room temperature for different time periods till they reached their saturation state. The tensile, flexural, and impact properties of water immersed specimens were conducted and compared with dry specimens as per the ASTM standard. It is concluded that the water uptake of basalt fibre is considerable loss in the mechanical properties of the composites.

  18. Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre

    Science.gov (United States)

    Shafiq, Nasir; Fadhilnuruddin, Muhd; Elshekh, Ali Elheber Ahmed; Fathi, Ahmed

    2015-07-01

    Ultrasonic pulse velocity (UPV), is considered as the most important test for non-destructive techniques that are used to evaluate the mechanical characteristics of high strength concrete (HSC). The relationship between the compressive strength of HSC containing chopped basalt fibre stands (CBSF) and UPV was investigated. The concrete specimens were prepared using a different ratio of CBSF as internal strengthening materials. The compressive strength measurements were conducted at the sample ages of 3, 7, 28, 56 and 90 days; whilst, the ultrasonic pulse velocity was measured at 28 days. The result of HSC's compressive strength with the chopped basalt fibre did not show any improvement; instead, it was decreased. The UPV of the chopped basalt fibre reinforced concrete has been found to be less than that of the control mix for each addition ratio of the basalt fibre. A relationship plot is gained between the cube compressive strength for HSC and UPV with various amounts of chopped basalt fibres.

  19. Corrosion of uncoated and oxide-coated basalt fibre in different alkaline media

    International Nuclear Information System (INIS)

    Rybin, V.A.; Utkin, A.V.; Baklanova, N.I.

    2016-01-01

    Highlights: • Alkaline corrosion of uncoated and coated basalt fibre in alkali media was studied. • Degradation of the fibre involves the dissolution of alumosilicate network in alkali media. • Insoluble shell from iron and calcium hydroxides and carbonates is formed. • Zirconia and titania coatings slow down the corrosion of basalt fibre significantly. - Abstract: The corrosion behaviour of the zirconium dioxide and titanium dioxide coated basalt fibre in sodium and calcium hydroxide solutions was studied. The morphology, elemental, phase composition of fibre before and after exposure to alkaline media was examined by different analytical techniques. It was shown that the oxide coatings slow down corrosion, and zirconium dioxide slows down corrosion of basalt fibre to a higher extent than titanium dioxide. The morphology and composition of solid corrosion products depend on a type of alkaline medium. The schemes of corrosion for the uncoated and coated basalt fibres in alkaline media were proposed.

  20. Electrical properties of phosphate glasses

    International Nuclear Information System (INIS)

    Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

    2009-01-01

    Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

  1. Glass matrix armor

    Science.gov (United States)

    Calkins, Noel C.

    1991-01-01

    An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.

  2. Sol-Gel Glasses

    Science.gov (United States)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  3. Theory of glass

    International Nuclear Information System (INIS)

    Rivier, N.

    1985-01-01

    The physical properties of glass are direct consequences of its non-crystalline structure. The structure is described from a topological point of view, since topology is the only geometry surviving non-crystallinity, i.e. absence of metric and trivial space group. This fact has two main consequences: the overall homogeneity of glass is a gauge symmetry, and the only extended, structurally stable constituents are odd lines (or 2π-disclinations in the elastic continuum limit). A gauge theory of glass, based on odd lines as sources of frozen-in strain, can explain those properties of glasses which are both specific to, and universal in amorphous solids: low-temperature excitations, and relaxation at high temperatures. The methods of statistical mechanics can be applied to give a minimal description of amorphous structures in statistical equilibrium. Criteria for statistical equilibrium of the structure and detailed balance are given, together with structural equations of state, which turn out to be well-known empirically among botanists and metallurgists. This review is based on lectures given in 1984 in Niteroi. It contains five parts: I - Structure, from a topological viewpoint; II - gauge invariance; III - Tunneling modes; IV - Supercooled liquid and the glass transitions; V - Statistical crystallography. (Author) [pt

  4. Geoscience parameter data base handbook: granites and basalts

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous United States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report.

  5. Fire performance of basalt FRP mesh reinforced HPC thin plates

    DEFF Research Database (Denmark)

    Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup

    2013-01-01

    An experimental program was carried out to investigate the influence of basalt FRP (BFRP) reinforcing mesh on the fire behaviour of thin high performance concrete (HPC) plates applied to sandwich elements. Samples with BFRP mesh were compared to samples with no mesh, samples with steel mesh...... and samples displaying a full sandwich structure. Final results confirmed the bond loss between concrete and BFRP mesh with temperature. The available void where the epoxy burnt away allowed the concrete matrix to release pressure and limit pore stresses, delaying spalling. It also reduced the mechanical...... on a linear increase of the volume of melted epoxy and the outflow of moisture from the concrete matrix. It was concluded that the use of a BFRP mesh to reinforce HPC exposed to fire reduces the mechanical strength despite a beneficial effect related to spalling....

  6. Nuclear waste repository in basalt: a design description

    International Nuclear Information System (INIS)

    Ritchie, J.S.; Schmidt, B.

    1982-01-01

    The conceptual design of a nuclear waste repository in basalt is described. Nuclear waste packages are placed in holes drilled into the floor of tunnels at a depth of 3700 ft. About 100 miles of tunnels are required to receive 35,000 packages. Five shafts bring waste packages, ventilation air, excavated rock, personnel, material, and services to and from the subsurface. The most important surface facility is the waste handling building, located over the waste handling shaft, where waste is received and packaged for storage. Two independent ventilation systems are provided to avoid potential contamination of spaces that do not contain nuclear waste. Because of the high temperatures at depth, an elaborate air chilling system is provided. Because the waste packages deliver a considerable amount of heat energy to the rock mass, particular attention is paid to heat transfer and thermal stress studies. 3 references, 31 figures, 3 tables

  7. Geomechanical testing development for the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    Cramer, M.L.; Dischler, S.A.; Erb, D.B.; Berlin, G.T.; Wittreich, C.D.; Bauer, R.E.

    1987-04-01

    One component of this project is the development of a geomechanical testing program to support repository design, site characterization, and performance assessment requirements. Geomechanics information includes characteristics of the in situ stress field and the mechanical properties of the rock mass. The nature of the basalts at the proposed repository depth of approximately 970 m imposes some relatively unusual requirements on testing methods typically used to assess the stress state and rock mass deformability. The rock mass is closely jointed, with the spacing estimated from vertical boreholes to be in the range of 5 to 10 cm for both vertical and horizontal joint sets. The ambient temperature at depth is about 50 0 C. The rock mass is considered fully saturated. This presentation summarizes the development effort currently under way to support site characterization testing to be conducted at the candidate repository horizon in the Exploratory Shaft Facility. Development activities include hydraulic fracturing, overcoring, flat jack testing, and borehole dilatometer testing

  8. Tungsten-182 heterogeneity in modern ocean island basalts

    Science.gov (United States)

    Mundl, Andrea; Touboul, Mathieu; Jackson, Matthew G.; Day, James M. D.; Kurz, Mark D.; Lekic, Vedran; Helz, Rosalind T.; Walker, Richard J.

    2017-04-01

    New tungsten isotope data for modern ocean island basalts (OIB) from Hawaii, Samoa, and Iceland reveal variable 182W/184W, ranging from that of the ambient upper mantle to ratios as much as 18 parts per million lower. The tungsten isotopic data negatively correlate with 3He/4He. These data indicate that each OIB system accesses domains within Earth that formed within the first 60 million years of solar system history. Combined isotopic and chemical characteristics projected for these ancient domains indicate that they contain metal and are repositories of noble gases. We suggest that the most likely source candidates are mega-ultralow-velocity zones, which lie beneath Hawaii, Samoa, and Iceland but not beneath hot spots whose OIB yield normal 182W and homogeneously low 3He/4He.

  9. Geoscience parameter data base handbook: granites and basalts

    International Nuclear Information System (INIS)

    1979-12-01

    The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous United States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report

  10. Interim reclamation report: Basalt Waste Isolation Project exploration shaft site

    International Nuclear Information System (INIS)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-02-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. Extensive studies of the geotechnical aspects of the site were undertaken, including preparations for drilling a large diameter Exploratory Shaft. This report describes the development of the reclamation program for the Exploratory Shaft Facility, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 43 refs., 19 figs., 9 tabs

  11. Interim reclamation report: Basalt Waste Isolation Project exploration shaft site

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.

    1990-02-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. Extensive studies of the geotechnical aspects of the site were undertaken, including preparations for drilling a large diameter Exploratory Shaft. This report describes the development of the reclamation program for the Exploratory Shaft Facility, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 43 refs., 19 figs., 9 tabs.

  12. Geochemistry of the 1989-1990 eruption of redoubt volcano: Part II. Evidence from mineral and glass chemistry

    Science.gov (United States)

    Swanson, S.E.; Nye, C.J.; Miller, T.P.; Avery, V.F.

    1994-01-01

    Early stages (December 1989) of the 1989-1990 eruption of Redoubt Volcano produced two distinct lavas. Both lavas are high-silica andesites with a narrow range of bulk composition (58-64 wt.%) and similar mineralogies (phenocrysts of plagioclase, hornblende, augite, hypersthene and FeTi oxides in a groundmass of the same phases plus glass). The two lavas are distinguished by groundmass glass compositions, one is dacitic and the other rhyolitic. Sharp boundaries between the two glasses in compositionally banded pumices, lack of extensive coronas on hornblende phenocrysts, and seismic data suggest that a magma-mixing event immediately preceeded the eruption in December 1989. Textural disequilibrium in the phenocrysts suggests both magmas (dacitic and rhyolitic glasses) had a mixing history prior to their interaction and eruption in 1989. Sievey plagioclase and overgrowths of magnetite on ilmenite are textures that are at least consistent with magma mixing. The presence of two hornblende compositions (one a high-Al pargasitic hornblende and one a low-Al magnesiohornblende) in both the dacitic and rhyolitic groundmasses indicates a mixing event to yield these two amphibole populations prior to the magma mixing in December 1989. The pargasitic hornblende and the presence of Ca-rich overgrowths in the sievey zones of the plagioclase together indicate at least one component of this earlier mixing event was a mafic magma, either a basalt or a basaltic andesite. Eruptions in 1990 produced only andesite with a rhyolitic groundmass glass. Glass compositions in the 1990 andesite are identical to the rhyolitic glass in the 1989 andesite. Cognate xenoliths from the magma chamber (or conduit) are also found in the 1990 lavas. Magma mixing probably triggered the eruption in 1989. The eruption ended when this rather viscous (rhyolitic groundmass glass, magma capable of entraining sidewall xenoliths) magma stabalized within the conduit. ?? 1994.

  13. Evaluation of aging and hydration in natural volcanic glass: magnetic property variations during artificial aging and hydration experiments

    Science.gov (United States)

    Bowles, J. A.; Patiman, A.

    2017-12-01

    The recorded geomagnetic field intensity is a function of magnetic mineralogy, grain size, and mineral concentration as well as material stability in nature and during laboratory experiments. Fresh, unhydrated, volcanic glasses are recognized as a nearly ideal natural material for use in paleointensity experiments because they contain the requisite single domain to pseudo-single-domain magnetic particles. Although alteration of magnetic mineralogy can be monitored during the experiments, it is unclear how mineralogy and hence magnetization might change with age as the metastable glass structure relaxes and/or the glass becomes hydrated. Bulk magnetic properties as a function of age show no clear trend, even over hundreds of millions of years. This may be due to the fact that even in fresh, unhydrated glass, there are small-scale differences in magnetic properties due to variation cooling rate or composition variations. Therefore, in order to better understand how magnetic mineralogy evolves with time and hydration, we conducted artificial aging and hydration experiments on fresh, unhydrated rhyolitic (South Deadman Creek, California, 650-yr) and basaltic (Axial Seamount, 2011) end-member glasses. Here, we present the results of artificial aging and hydration experiments. Elevated temperatures accelerate the glass relaxation process in a way that relaxation time decreases with increasing temperature. Aged samples are dry-annealed at 200, 300 and 400 °C for up to 240 days. A second set of samples are hydrated under pressure at 300°C and 450°C. In all cases, isothermal remanent magnetization (IRM) acquisition is monitored to assess changes in the coercivity spectrum and saturation IRM. Preliminary aging results show that in basaltic and rhyolitic glass there is one main peak coercivity at 150 mT and 35 mT, respectively. An increasing sIRM and decreasing peak coercivity trend is observed in basaltic glass whereas no trend is shown in the rhyolitic glass in both

  14. Repository site definition in basalt: Pasco Basin, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

    1982-03-01

    Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi/sup 2/ (5180 km/sup 2/) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process.

  15. Repository site definition in basalt: Pasco Basin, Washington

    International Nuclear Information System (INIS)

    Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

    1982-03-01

    Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi 2 (5180 km 2 ) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process

  16. Tracking Hadean processes in modern basalts with 142-Neodymium

    Science.gov (United States)

    Horan, M. F.; Carlson, R. W.; Walker, R. J.; Jackson, M.; Garçon, M.; Norman, M.

    2018-02-01

    The short-lived 146Sm→142 Nd isotope system (t1/2 = 103 Ma) provides constraints on the timing and processes of terrestrial silicate fractionation during the early Hadean. Although some Archean terranes preserve variability in 142Nd/144Nd, no anomalies have been resolved previously in young rocks. This study provides high precision 142Nd/144Nd data on a suite of ocean island basalts from Samoa and Hawaii previously shown to have variable depletions in 182W/184W that are inversely correlated with 3He/4He ratios. Improved analytical techniques and multiple replicate analyses of Nd show a variation in μ142 Nd values between -1.3 and +2.7 in the suite, relative to the JNdi standard. Given the reproducibility of the standard (±2.9 ppm, 2 SD), two Samoan samples exhibit resolved variability in their 142Nd/144Nd ratios outside of their 95% confidence intervals, suggesting minor variability in the Samoan hotspot. One sample from Samoa has a higher μ142 Nd of +2.7, outside the 95% confidence interval (±1.0 ppm) of the average of the JNdi standard. Limited, but resolved, variation in 142Nd/144Nd within the suite suggests the preservation of early Hadean silicate differentiation in the sources of at least some basalts from Samoa. Larger variations of 182W/184W and 3He/4He ratios in the same samples suggest that metal-silicate separation and mantle outgassing left a more persistent imprint on the accessible mantle compared to 142Nd/144Nd ratios which are impacted by early silicate differentiation.

  17. The Influence of Topographic Obstacles on Basaltic Lava Flow Morphologies

    Science.gov (United States)

    von Meerscheidt, H. C.; Brand, B. D.; deWet, A. P.; Bleacher, J. E.; Hamilton, C. W.; Samuels, R.

    2014-12-01

    Smooth pāhoehoe and jagged ´áā represent two end-members of a textural spectrum that reflects the emplacement characteristics of basaltic lava flows. However, many additional textures (e.g., rubbly and slabby pāhoehoe) reflect a range of different process due to lava flow dynamics or interaction with topography. Unfortunately the influence of topography on the distribution of textures in basaltic lava flows is not well-understood. The 18 ± 1.0 ka Twin Craters lava flow in the Zuni-Bandera field (New Mexico, USA) provides an excellent site to study the morphological changes of a lava flow that encountered topographic obstacles. The flow field is 0.2-3.8 km wide with a prominent central tube system that intersects and wraps around a 1000 m long ridge, oriented perpendicular to flow. Upstream of the ridge, the flow has low-relief inflation features extending out and around the ridge. This area includes mildly to heavily disrupted pāhoehoe with interdispersed agglutinated masses, irregularly shaped rubble and lava balls. Breakouts of ´áā and collapse features are also common. These observations suggest crustal disruption due to flow-thickening upstream from the ridge and the movement of lava out and around the obstacle. While the ridge influenced the path of the tube, which wraps around the southern end of the ridge, the series of collapse features and breakouts of ´áā along the tube system are more likely a result of changes in flux throughout the tube system because these features are found both upstream and downstream of the obstacle. This work demonstrates that topography can significantly influence the formation history and surface disruption of a flow field, and in some cases the influence of topography can be separated from the influences of changes in flux along a tube system.

  18. Permeability and mechanical properties of cracked glass under pressure

    International Nuclear Information System (INIS)

    Ougier-Simonin, A.

    2010-01-01

    permeability even for a high damage level (10 -17 ≤k≤ 10 -21 m 2 ). This permeability decreases with the increasing confining pressure following a cubic crack aperture law. This crack aperture first dominates the increasing mechanical damage under deviatoric stress, then mechanical cracks develops leading to the sample macroscopic failure. However, the glass amorphous structure makes it very different from any rock structure. We show that a micro-crystallized rock remains different from a glass in terms of mechanical behavior but exhibits dynamical elastic parameters close from the glass ones. For the nuclear waste context, this basalt is a interesting analog in terms of elastic parameter evolution under pressure. (author)

  19. The mode of emplacement of Neogene flood basalts in eastern Iceland: Facies architecture and structure of simple aphyric basalt groups

    Science.gov (United States)

    Óskarsson, Birgir V.; Riishuus, Morten S.

    2014-12-01

    Simple flows (tabular) in the Neogene flood basalt sections of Iceland are described and their mode of emplacement assessed. The flows belong to three aphyric basalt groups: the Kumlafell group, the Hólmatindur group and the Hjálmadalur group. The groups can be traced over 50 km and originate in the Breiðdalur-Thingmuli volcanic zone. The groups have flow fields that display mixed volcanic facies architecture and can be classified after dominating type morphology. The Kumlafell and the Hólmatindur groups have predominantly simple flows of pāhoehoe and rubbly pāhoehoe morphologies with minor compound or lobate pāhoehoe flows. The Hjálmadalur group has simple flows of rubbly pāhoehoe, but also includes minor compound or lobate flows of rubble and 'a'ā. Simple flows are most common in the distal and medial areas from the vents, while more lobate flows in proximal areas. The simple flows are formed by extensive sheet lobes that are several kilometers long with plane-parallel contacts, some reaching thicknesses of ~ 40 m (aspect ratios structures. Their internal structure consists generally of a simple upper vesicular crust, a dense core and a thin basal vesicular zone. The brecciated flow-top is formed by clinker and crustal rubble, the clinker often welded or agglutinated. The simple flows erupted from seemingly short-lived fissures and have the characteristics of cooling-limited flows. We estimate the effusion rates to be ~ 105 m3/s for the simple flows of the Kumlafell and Hólmatindur groups and ~ 104 m3/s for the Hjálmadalur group. The longest flows advanced 15-20 km from the fissures, with lava streams of fast propagating flows inducing tearing and brecciation of the chilled crust. Compound or lobate areas appear to reflect areas of low effusion rates or the interaction of the lava with topographic barriers or wetlands, resulting in chaotic flowage. Slowing lobes with brecciated flow-tops developed into 'a'ā flows. The groups interdigitated with lava

  20. Using physical properties of molten glass to estimate glass composition

    International Nuclear Information System (INIS)

    Choi, Kwan Sik; Yang, Kyoung Hwa; Park, Jong Kil

    1997-01-01

    A vitrification process is under development in KEPRI for the treatment of low-and medium-level radioactive waste. Although the project is for developing and building Vitrification Pilot Plant in Korea, one of KEPRI's concerns is the quality control of the vitrified glass. This paper discusses a methodology for the estimation of glass composition by on-line measurement of molten glass properties, which could be applied to the plant for real-time quality control of the glass product. By remotely measuring viscosity and density of the molten glass, the glass characteristics such as composition can be estimated and eventually controlled. For this purpose, using the database of glass composition vs. physical properties in isothermal three-component system of SiO 2 -Na 2 O-B 2 O 3 , a software TERNARY has been developed which determines the glass composition by using two known physical properties (e.g. density and viscosity)

  1. Porous vycor glass tube joined to borosilicate glass

    Science.gov (United States)

    Abe, Shinichi; Kikuchi, Takemitsu; Onodera, Shinji

    1992-09-01

    Porous glass can absorb various size of molecules with large surface area even in high temperature. However, it is difficult to use porous glass tubes at high-temperature, for example as a separation membrane for hydrogen condensation, because adhesives at joining sites could be damaged. In this study, welding of a porous glass tube and a glass tube was attempted to develop a gas separation membrane used at 500 C. Since forms present in porous glass may cause crack at high temperature, it is necessary to remove such forms by heat processing. Such porous glass is called to be porous vycor glass, which contains quartz 6 percents, and can be joined with a quartz tube. As a result, a gas separator with porous glass membrane which is joined by this process could endure high temperature up to 600 C and could maintain high vacuum.

  2. SRL in-situ tests in the United Kingdom: Part 2, Surface analyses of SRS waste glass buried for one and two years in limestone at Ballidon, UK

    International Nuclear Information System (INIS)

    Namboodri, C.G. Jr.; Wicks, G.G.

    1991-01-01

    A multiphase experimental program to assess and understand waste glass behavior under a wide range of conditions has been in progress at the Savannah River Laboratory (SRL) for over a decade. An important part of this experimental effort is to assess the effects of repository relevant conditions on performance of SRS waste glass, in both controlled laboratory tests, as well as in actual field experiments. In laboratory test, SRS waste glass, simulated and in many cases also fully radioactive, has been tested in environments of salt, basalt, shale, granite, clay and tuff. In field experiments, there are four joint international programs being conducted in four different countries, involving burial of SRS simulated waste glass in granite, limestone, clay and salt geologies. This report discusses the SRS waste glass studies in limestone at Ballidon, UK

  3. Petrological and Geochemical characterization of central Chihuahua basalts: a possible local sign of rifting activity

    Science.gov (United States)

    Espejel-Garcia, V. V.; Garcia-Rascon, M.; Villalobos-Aragon, A.; Morton-Bermea, O.

    2012-12-01

    The central part of the mexican state, Chihuahua, is the oriental border of the Sierra Madre Occidental (silicic large igneous province), which consist of series of ignimbrites divided into two volcanic groups of andesites and rhyolites. In the central region of Chihuahua, the volcanic rocks are now part of the Basin and Range, allowing the presence of mafic rocks in the lower areas. The study area is located approximately 200 km to the NW of Chihuahua city near to La Guajolota town, in the Namiquipa County. There are at least 5 outcrops of basalts to the west of the road, named Puerto de Lopez, Malpaises, El Tascate, Quebrada Honda, and Carrizalio, respectively. These outcrops have only been previously described by the Mexican Geologic Survey (SGM) as thin basaltic flows, with vesicles filled with quartz, and phenocrystals of labradorite, andesine, oligoclase and olivine. Petrologically, the basalts present different textures, from small phenocrysts of plagioclase in a very fine matrix to large, zoned and sometimes broken phenocrysts of plagioclase in a coarser matrix. All samples have olivine in an advanced state of alteration, iddingsite. The geochemical analyses report that these basaltic flows contain characteristics of rift basalts. The rocks have a normative olivine values from 5.78 to 27.26 and nepheline values from 0 to 2.34. In the TAS diagram the samples straddle the join between basalt and trachy-basalt, reflecting a high K2O content. The Mg# average is 0.297, a value that suggests that the basalts do not come from a primitive magma. The basalts have high values of Ba (945-1334 ppm), Cu (54-147 ppm), and Zn (123-615 ppm). The contents of Rb (23-57 ppm), Sr (659-810 ppm), Y (26-33 ppm), Zr (148-217 ppm) and Cr (79-98 ppm) are characteristics of rift basalts. Using discrimination diagrams, the basalts plot in the field of within plate, supporting the rifting origin. Outcrops of other basalts, at about 80 to 100 km to the east of the study area, Lomas El

  4. Mars on Earth: Analog basaltic soils and particulates from Lonar Crater, India, include Deccan soil, shocked soil, reworked lithic and glassy ejecta, and both shocked and unshocked baked zones

    Science.gov (United States)

    Wright, S. P.

    2017-12-01

    "There is no perfect analog for Mars on Earth" [first line of Hipkin et al. (2013) Icarus, 261-267]. However, fieldwork and corresponding sample analyses from laboratory instrumentation (to proxy field instruments) has resulted in the finding of unique analog materials that suggest that detailed investigations of Lonar Crater, India would be beneficial to the goals of the Mars Program. These are briefly described below as Analog Processes, Materials, and Fieldwork. Analog Processes: The geologic history of Lonar Crater emulates localities on Mars with 1.) flood basaltic volcanism with interlayer development of 2.) baked zones or "boles" and 3.) soil formation. Of six flows, the lower three are aqueously altered by groundwater to produce a range of 4.) alteration products described below. The impact event 570 ka produced a range of 5.) impactites including shocked baked zones, shocked soils, and altered basalt shocked to a range of shock pressures [Kieffer et al., 1976]. Analog Materials: 65 Ma Deccan basalt contains augite and labradorite. Baked zones are higher in hematite and other iron oxides. Soil consists of calcite and organic matter. Several basalts with secondary alteration are listed here and these mirror alteration on Mars: hematite, chlorite, serpentine, zeolite, and palagonite, with varying combinations of these with primary igneous minerals. All of these materials (#1 through 4 above) are shocked to a range of shocked pressures to produce maskelynite, flowing plagioclase glass, vesiculated plagioclase glass, and complete impact melts. Shocked soils contain schlieren calcite amidst comminuted grains of augite, labradorite, and these glasses. Shocked baked zones unsurprisingly have a petrographic texture similar to hornfels, another product of contact metamorphism. Analog Fieldwork: The ejecta consists of two layers: 8 m of lithic breccia with unshocked and fractured basalts under a 1 m suevite consisting of all ranges of shock pressure described above

  5. Probability encoding of hydrologic parameters for basalt. Elicitation of expert opinions from a panel of three basalt waste isolation project staff hydrologists

    International Nuclear Information System (INIS)

    Runchal, A.K.; Merkhofer, M.W.; Olmsted, E.; Davis, J.D.

    1984-11-01

    The present study implemented a probability encoding method to estimate the probability distributions of selected hydrologic variables for the Cohassett basalt flow top and flow interior, and the anisotropy ratio of the interior of the Cohassett basalt flow beneath the Hanford Site. Site-speciic data for these hydrologic parameters are currently inadequate for the purpose of preliminary assessment of candidate repository performance. However, this information is required to complete preliminary performance assessment studies. Rockwell chose a probability encoding method developed by SRI International to generate credible and auditable estimates of the probability distributions of effective porosity and hydraulic conductivity anisotropy. The results indicate significant differences of opinion among the experts. This was especially true of the values of the effective porosity of the Cohassett basalt flow interior for which estimates differ by more than five orders of magnitude. The experts are in greater agreement about the values of effective porosity of the Cohassett basalt flow top; their estimates for this variable are generally within one to two orders of magnitiude of each other. For anisotropy ratio, the expert estimates are generally within two or three orders of magnitude of each other. Based on this study, the Rockwell hydrologists estimate the effective porosity of the Cohassett basalt flow top to be generally higher than do the independent experts. For the effective porosity of the Cohassett basalt flow top, the estimates of the Rockwell hydrologists indicate a smaller uncertainty than do the estimates of the independent experts. On the other hand, for the effective porosity and anisotropy ratio of the Cohassett basalt flow interior, the estimates of the Rockwell hydrologists indicate a larger uncertainty than do the estimates of the independent experts

  6. Compositional and Microtextural Analysis of Basaltic Feedstock Materials Used for the 2010 ISRU Field Tests, Mauna Kea, Hawaii

    Science.gov (United States)

    Marin, N.; Farmer, J. D.; Zacny, K.; Sellar, R. G.; Nunez, J.

    2011-12-01

    This study seeks to understand variations in composition and texture of basaltic pyroclastic materials used in the 2010 International Lunar Surface Operation-In-Situ Resource Utilization Analogue Test (ILSO-ISRU) held on the slopes of Mauna Kea Volcano, Hawaii (1). The quantity and quality of resources delivered by ISRU depends upon the nature of the materials processed (2). We obtained a one-meter deep auger cuttings sample of a basaltic regolith at the primary site for feed stock materials being mined for the ISRU field test. The auger sample was subdivided into six, ~16 cm depth increments and each interval was sampled and characterized in the field using the Multispectral Microscopic Imager (MMI; 3) and a portable X-ray Diffractometer (Terra, InXitu Instruments, Inc.). Splits from each sampled interval were returned to the lab and analyzed using more definitive methods, including high resolution Powder X-ray Diffraction and Thermal Infrared (TIR) spectroscopy. The mineralogy and microtexture (grain size, sorting, roundness and sphericity) of the auger samples were determined using petrographic point count measurements obtained from grain-mount thin sections. NIH Image J (http://rsb.info.nih.gov/ij/) was applied to digital images of thin sections to document changes in particle size with depth. Results from TIR showed a general predominance of volcanic glass, along with plagioclase, olivine, and clinopyroxene. In addition, thin section and XRPD analyses showed a down core increase in the abundance of hydrated iron oxides (as in situ weathering products). Quantitative point count analyses confirmed the abundance of volcanic glass in samples, but also revealed olivine and pyroxene to be minor components, that decreased in abundance with depth. Furthermore, point count and XRD analyses showed a decrease in magnetite and ilmenite with depth, accompanied by an increase in Fe3+phases, including hematite and ferrihydrite. Image J particle analysis showed that the

  7. Aging in a Structural Glass

    OpenAIRE

    Kob, Walter; Barrat, Jean-Louis

    1998-01-01

    We discuss the relaxation dynamics of a simple structural glass which has been quenched below its glass transition temperature. We demonstrate that time correlation functions show strong aging effects and investigate in what way the fluctuation dissipation theorem is violated.

  8. Application of the iron-enriched basalt waste form for immobilizing commercial transuranic waste

    International Nuclear Information System (INIS)

    Owen, D.E.

    1981-08-01

    The principal sources of commercial transuranic (TRU) waste in the United States are identified. The physical and chemical nature of the wastes from these sources are discussed. The fabrication technique and properties of iron-enriched basalt, a rock-like waste form developed for immobilizing defense TRU wastes, are discussed. The application of iron-enriched basalt to commercial TRU wastes is discussed. Review of commercial TRU wastes from mixed-oxide fuel fabrication, light water reactor fuel reprocessing, and miscellaneous medical, research, and industrial sources, indicates that iron-enriched basalt is suitable for most types of commercial TRU wastes. Noncombustible TRU wastes are dissolved in the high temperature, oxidizing iron-enriched basalt melt. Combustible TRU wastes are immobilized in iron-enriched basalt by incinerating the wastes and adding the TRU-bearing ash to the melt. Casting and controlled cooling of the melt produces a devitrified, rock-like iron-enriched basalt monolith. Recommendations are given for testing the applicability of iron-enriched basalt to commercial TRU wastes

  9. Stratigraphic imaging of sub-basalt sediments using waveform tomography of wide-angle seismic data

    Science.gov (United States)

    Sain, K.; Gao, F.; Pratt, G.; Zelt, C. A.

    2003-12-01

    The oil industry is interested in imaging the fine structures of sedimentary formations masked below basalt flows for commercial exploration of hydrocarbons. Seismic exploration of sediments hidden below high-velocity basalt cover is a difficult problem because near-vertical reflection data are contaminated with multiples, converted waves and scattering noise generated by interbeds, breccia and vesicles within the basalt. The noise becomes less prominent as the source-receiver offset increases, and the signals carrying sub-surface information stand out at the wide-angle range. The tomography of first arrival traveltime data can provide little information about the underlying low-velocity sediments. Traveltime inversion of wide-angle seismic data including both first arrivals and identifiable wide-angle reflected phases has been an important tool in the delineation of the large-scale velocity structure of sub-basalt sediments, although it lacks the small-scale velocity details. Here we apply 2-D full-waveform inversion ("waveform tomography") to wide-angle seismic data with a view to extracting the small-scale stratigraphic features of sedimentary formations. Results from both synthetic data, generated for a realistic earth model, and field dataset from the basalt covered Saurashtra peninsula, India, will be presented. This approach has potential to delineate thin sedimentary layers hidden below thick basalt cover also, and may serve as a powerful tool to image sedimentary basins, where they are covered by high-velocity materials like basalts, salts, carbonates, etc. in various parts of the world.

  10. What Glass Ceiling?

    Science.gov (United States)

    Lynch, Michael; Post, Katherine

    1996-01-01

    A recent study drawing on data from the Census Bureau and the Bureau of Labor Statistics suggests that the wage gap between men and women has virtually disappeared, and that the so-called "glass ceiling" results more from age and qualifications than from explicit discrimination. (SLD)

  11. Glass ceilings of professionalisation.

    Science.gov (United States)

    Stott, Dawn L

    2016-04-01

    The term glass ceiling is a political term often used to describe an unbreakable barrier that isnot visible with the human eye, but it keeps minorities from rising up i.e. it is a barrier to minoritygroups, in the past (and sometimes still) for women, that stops them from achieving theirtrue potential.

  12. in glass transition region

    Indian Academy of Sciences (India)

    Unknown

    compositions of arsenic. An effort has also been made to develop an empirical model for the composition dependence of ∆H. A good agreement has been observed between the experimental values and the results of model calculation. Keywords. Glass transition temperature; activation energy; heat absorbed; composition ...

  13. Glass as matter

    DEFF Research Database (Denmark)

    Beim, Anne

    2000-01-01

    Refraiming the Moderns - Substitute Windows and Glass. In general terms, the seminar has contributed to the growing interest in the problems concerning the restoration of Modern Movement architecture. More particularly, it has of course drawn our attention to modern windows, which are increasingl...... recognized as precious and important feature, both for technical resons and for their expression af aesthetic values....

  14. "Stained Glass" Landscape Windows

    Science.gov (United States)

    Vannata, Janine

    2008-01-01

    Both adults and children alike marvel at the grand vivid stained-glass windows created by American artist Louis Comfort Tiffany. Today he is commonly recognized as one of America's most influential designers and artists throughout the last nineteenth and early twentieth century. In the lesson described in this article, students created their own…

  15. in glass transition region

    Indian Academy of Sciences (India)

    Unknown

    wave-guides e.g. in welding and surgery (Nishi et al. 1992). Especially amorphous chalcogenide alloys exhibit the property of reversible transformation. This property makes these systems very useful in optical memory. Glasses are amorphous (Elliot 1990) in nature, i.e. they form a disordered and metastable structure.

  16. Glass as matter

    DEFF Research Database (Denmark)

    Beim, Anne

    2000-01-01

    Refraiming the Moderns - Substitute Windows and Glass. In general terms, the seminar has contributed to the growing interest in the problems concerning the restoration of Modern Movement architecture. More particularly, it has of course drawn our attention to modern windows, which are increasingl...

  17. Stained Glass and Flu

    Centers for Disease Control (CDC) Podcasts

    2017-02-01

    Dr. Robert Webster, an Emeritus member of the Department of Infectious Diseases at St. Jude Children's Research Hospital, discusses his cover art story on stained glass and influenza.  Created: 2/1/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/1/2017.

  18. Mantle heterogeneity in the source region of mid-ocean ridge basalts along the northern Central Indian Ridge (8°S-17°S)

    Science.gov (United States)

    Kim, Jonguk; Pak, Sang-Joon; Moon, Jai-Woon; Lee, Sang-Mook; Oh, Jihye; Stuart, Finlay M.

    2017-04-01

    The northern Central Indian Ridge (CIR) between 8°S and 17°S is composed of seven segments whose spreading rates increase southward from ˜35 to ˜40 mm/yr. During expeditions of R/V Onnuri to study hydrothermal activity on the northern CIR in 2009-2011, high-resolution multibeam mapping was conducted and ridge axis basalts were dredged. The major and trace element and Sr-Nd-Pb-He isotopic compositions of basaltic glasses dredged from the spreading axis require three mantle sources: depleted mantle and two distinct enriched mantle sources. The southern segments have Sr, Nd, and Pb that are a mix of depleted mantle and an enriched component as recorded in southern CIR MORB. This enrichment is indistinguishable from Rèunion plume mantle, except for He isotopes. This suggests that the southern segments have incorporated a contribution of the fossil Rèunion plume mantle, as the CIR migrated over hot-spot-modified mantle. The low 3He/4He (7.5-9.2 RA) of this enriched component may result from radiogenic 4He ingrowth in the fossil Rèunion mantle component. Basalts from the northern segments have high 206Pb/204Pb (18.53-19.15) and low 87Sr/86Sr (0.70286-0.70296) that are distinct from the Rèunion plume but consistent with derivation from mantle with FOZO signature, albeit with 3He/4He (9.2-11.8 RA) that are higher than typical. The FOZO-like enriched mantle cannot be attributed to the track of a nearby mantle plume. Instead, this enrichment may have resulted from recycling oceanic crust, possibly accompanied by small plume activity.

  19. Glasses and nuclear waste vitrification

    International Nuclear Information System (INIS)

    Ojovan, Michael I.

    2012-01-01

    Glass is an amorphous solid material which behaves like an isotropic crystal. Atomic structure of glass lacks long-range order but possesses short and most probably medium range order. Compared to crystalline materials of the same composition glasses are metastable materials however crystallisation processes are kinetically impeded within times which typically exceed the age of universe. The physical and chemical durability of glasses combined with their high tolerance to compositional changes makes glasses irreplaceable when hazardous waste needs immobilisation for safe long-term storage, transportation and consequent disposal. Immobilisation of radioactive waste in glassy materials using vitrification has been used successfully for several decades. Nuclear waste vitrification is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting wasteform. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material. Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes. In addition to relatively homogeneous glasses novel glass composite materials are used to immobilise problematic waste streams. (author)

  20. Yesterday's Trash Makes Tomorrow's "Glass"

    Science.gov (United States)

    Wayne, Dale

    2010-01-01

    In this article, the author describes a glass art project inspired by Dale Chihuly. This project uses two-liter plastic soda bottles which are cut apart and trimmed. Applying heat using a hair dryer, the plastic curls and takes an uneven blown-glass quality. The "glass" is then painted using acrylic paint. (Contains 2 resources and 1 online…

  1. Analysis of glass fibre sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2014-01-01

    . Soxhlet extraction was used to extract components of the sizing from the glass fibres. The glass fibres, their extracts and coated glass plates were analysed by Thermo-Gravimetric Analysis combined with a mass spectrometer (TGA-MS), and Attenuated Total Reflectance Fourier Transform Infrared (ATR...

  2. Basalt models for the Mars penetrator mission: Geology of the Amboy Lava Field, California

    Science.gov (United States)

    Greeley, R.; Bunch, T. E.

    1976-01-01

    Amboy lava field (San Bernardino County, California) is a Holocene basalt flow selected as a test site for potential Mars Penetrators. A discussion is presented of (1) the general relations of basalt flow features and textures to styles of eruptions on earth, (2) the types of basalt flows likely to be encountered on Mars and the rationale for selection of the Amboy lava field as a test site, (3) the general geology of the Amboy lava field, and (4) detailed descriptions of the target sites at Amboy lava field.

  3. Study of rhyolitic glasses alteration in contact with natural brines (Bolivia). Application to the study of the long-term behaviour of the R7T7 nuclear glass

    International Nuclear Information System (INIS)

    Abdelouas, A.

    1996-01-01

    The purpose of this work is to complement an experimental program on the R7T7 nuclear waste glass alteration in brines at 190 deg C in Germany by the analysis of the structure and the chemical composition of the alteration layers, and to study the alteration of rhyolitic glasses in natural brines from Bolivia as analogue for nuclear waste glasses disposed in salt formations. Alteration experiments with the R7T7 and basaltic glasses and obsidian in MgCl 2 -CaCl 2 -saturated brine at 190 deg. C were also conducted in order to study the influence of the glass composition on the nature of the secondary phases. The experiments with the R7T7 glass in three salt brines, saturated respectively in MgCl 2 , MgCl 2 -CaCl 2 and NaCl, showed that the solubilities of most radionuclides are controlled by the secondary phases. Nd, La, and Pr are trapped in powellite, Ce in cerianite, U in coffinite, and Sr is partially immobilized in barite. These phases are stable for more than one year. There is a good similarity between the secondary phases formed experimentally on volcanic glasses and the R7T7 glass altered in MgCl 2 -CaCl 2 -saturated brine. The abundance of Mg in solution permits the formation of similar magnesian clays on the glass samples independently of the nature of the initial glasses. These results support the use of volcanic glasses alteration patterns in Mg-rich solutions to understand the long-term behavior of nuclear waste glasses and to evaluate the stability of the secondary phases. The study of the sediments of Uyuni (Bolivia) showed that the corrosion rate of the rhyolitic glass in brines at 10 deg. C is 12 to 30 time lower than those of rhyolitic glasses altered in high dilute conditions. The low alteration rate of rhyolitic glasses in brines and the formation of secondary phases such as smectite, barite and cerianite (also formed during the experimental alteration of the R7T7 glass), permit us to expect the low alteration of nuclear waste glasses at long

  4. U-based metallic glasses with superior glass forming ability

    Science.gov (United States)

    Xu, Hongyang; Ke, Haibo; Huang, Huogen; Zhang, Pengguo; Pu, Zhen; Zhang, Pei; Liu, Tianwei

    2018-02-01

    By using Al as the third and B as the fourth but minor alloying elements for the U66.7Co33.3 basic metallic glass, a series of U-Co-Al(-B) alloys were designed. The quaternary U-Co-Al-B alloys exhibit significantly improved glass-forming ability (GFA) than previously reported U-based metallic glasses. Low fragility (∼24) is found for these new U-based metallic glasses. The improvement in GFA would result from denser atomic packing in the undercooled liquids due to the presence of small B atoms. Some U-Co-Al(-B) glasses showed corrosion resistance comparable to that of U64Co34Al2 glass, known for premium anti-corrosive performance among the unveiled U-based glasses.

  5. Petrogenesis of basalt-trachyte lavas from Olmoti Crater, Tanzania

    Science.gov (United States)

    Mollel, Godwin F.; Swisher, Carl C., III; McHenry, Lindsay J.; Feigenson, Mark D.; Carr, Michael J.

    2009-08-01

    Olmoti Crater is part of the Plio-Pleistocene Ngorongoro Volcanic Highland (NVH) in northern Tanzania to the south of Gregory Rift. The Gregory Rift is part of the eastern branch of the East African Rift System (EARS) that stretches some 4000 km from the Read Sea and Gulf of Aden in the north to the Zambezi River in Mozambique. Here, we (1) characterize the chemistry and mineral compositions of lavas from Olmoti Crater, (2) determine the age and duration of Olmoti volcanic activity through 40Ar/ 39Ar dating of Olmoti Crater wall lavas and (3) determine the genesis of Olmoti lavas and the relationship to other NVH and EARS volcanics and (4) their correlation with volcanics in the Olduvai and Laetoli stratigraphic sequences. Olmoti lavas collected from the lower part of the exposed crater wall section (OLS) range from basalt to trachyandesite whereas the upper part of the section (OUS) is trachytic. Petrography and major and trace element data reflect a very low degree partial melt origin for the Olmoti lavas, presumably of peridotite, followed by extensive fractionation. The 87Sr/ 86Sr data overlap whereas Nd and Pb isotope data are distinct between OLS and OUS samples. Interpretation of the isotope data suggests mixing of enriched mantle (EM I) with high-μ-like reservoirs, consistent with the model of Bell and Blenkinsop [Bell, K., Blenkinsop, J., 1987. Nd and Sr isotopic compositions of East African carbonatites: implications for mantle heterogeneity. Geology 5, 99-102] for East African carbonatite lavas. The isotope ratios are within the range of values defined by Oceanic Island Basalt (OIB) globally and moderate normalized Tb/Yb ratios (2.3-1.6) in these lavas suggest melting in the lithospheric mantle consistent with other studies in the region. 40Ar/ 39Ar incremental-heating analyses of matrix and anorthoclase separates from Olmoti OLS and OUS lavas indicate that volcanic activity was short in duration, lasting ˜200 kyr from 2.01 ± 0.03 Ma to 1.80 ± 0

  6. The Auckland Volcanic Field - a basaltic field showing random behavior?

    Science.gov (United States)

    Le Corvec, N.; Rowland, J. V.; Lindsay, J. M.

    2012-04-01

    Basaltic monogenetic volcanism is a worldwide phenomenon typically producing fields of volcanic centers that increase in number with time. The process of field growth is not constant but punctuated by single eruptions, flare-ups and hiatuses. The development of a volcanic field involves physical processes that occur in the mantle, where batches of basaltic magma originate, and within the intervening lithosphere through which magma is transferred to the surface. The spatial and temporal distribution of volcanic centers within such volcanic fields results from, and thus may provide insights to, these physical processes (e.g., magma production, tectonic controls), thereby aiding in our understanding of a volcanic field's future development. The Auckland Volcanic Field (AVF), which lies in the most populated area of New Zealand, comprises 50 volcanic centers and produced its last eruption ~600 years ago. A recent study has provided a relative chronology of the entire sequence of eruptions, which is here used together with the spatial distribution of volcanic centers to investigate the evolution of the field in time and space. Two methods were used: 1) the Poisson Nearest Neighbor (PNN) analysis which evaluates the spatial distribution of a natural population over the spatial distribution of a statistical random model, the Poisson model; and 2) the Voronoi analysis which evaluates the spatial characteristics of each volcanic center by dividing a region (i.e., the volcanic field) into a set of polygons. The results of the PNN analysis show that the temporal evolution of the spatial distribution of the volcanic centers within the AVF follows the Poisson model, therefore they cannot be used to extrapolate the future evolution of the volcanic field. The preliminary results of the Voronoi analysis show in combination with the geochemical signatures from some volcanic centers a possible zonation within the source region, and/or the magmas may be variably affected on their way

  7. Submarine basaltic fountain eruptions in a back-arc basin during the opening of the Japan Sea

    Science.gov (United States)

    Hosoi, Jun; Amano, Kazuo

    2017-11-01

    Basaltic rock generated during the middle Miocene opening of the Japan Sea, is widely distributed on the back-arc side of the Japanese archipelago. Few studies have investigated on submarine volcanism related to opening of the Japan Sea. The present study aimed to reconstruct details of the subaqueous volcanism that formed the back-arc basin basalts (BABB) during this event, and to discuss the relationship between volcanism and the tectonics of back-arc opening, using facies analyses based on field investigation. The study area of the southern Dewa Hills contains well-exposed basalt related to the opening of the Japan Sea. Five types of basaltic rock facies are recognized: (1) coherent basalt, (2) massive platy basalt, (3) jigsaw-fit monomictic basaltic breccia, (4) massive or stratified coarse monomictic basaltic breccia with fluidal clasts, and (5) massive or stratified fine monomictic basaltic breccia. The basaltic rocks are mainly hyaloclastite. Based on facies distributions, we infer that volcanism occurred along fissures developed mainly at the center of the study area. Given that the rocks contain many fluidal clasts, submarine lava fountaining is inferred to have been the dominant eruption style. The basaltic rocks are interpreted as the products of back-arc volcanism that occurred by tensional stress related to opening of the Japan Sea, which drove strong tectonic subsidence and active lava fountain volcanism.

  8. Draft site characterization analysis of the site characterization report for the Basalt Waste Isolation Project, Hanford, Washington site. Appendices E through W

    International Nuclear Information System (INIS)

    1983-03-01

    Volume 2 contains Appendices E through W: potential for large-scale pump tests in the Grande Ronde; review of hydrochemical characterization related to flow system interpretation in Hanford basalts; limitations of packer-testing for head evaluation in Hanford basalts; hydrogeologic data integration for conceptual groundwater flow models; drilling mud effects on hydrogeologic testing; site issue analyses related to the nature at the present groundwater system at the Hanford site, Washington; structural and stratigraphic characteristics related to groundwater flow at the Hanford site, Washington; seismic hazard and some examples of hazard studies at Hanford; earthquake swarms in the Columbia Plateau; seismic ground motion at depth; failure modes for the metallic waste package component; degradation mechanisms of borosilicate glass; transport and retardation of radionuclides in the waste package; determination and interpretation of redox conditions and changes in underground high-level repositories; determination and interpretation of sorption data applied to radionuclide migration in underground repositories; solubility of radionuclide compounds presented in the BWIP site characterization report; and release rate from engineered system

  9. Petrological, magnetic and chemical properties of basalt dredged from an abyssal hill in the North-east pacific

    Science.gov (United States)

    Luyendyk, B.P.; Engel, C.G.

    1969-01-01

    OVER the years, samples of basalt from the oceanic crust have been taken mainly from seamounts, fracture zones and ridge and rise crests1-6, and rarely from the vast fields of abyssal hills which cover a large part of the deep-sea floor. The basalt sampled from the deeper regions of the oceanic crust (for example, on fault scarps) is a distinct variety of tholeiitic basalt, while alkali basalt is restricted to the volcanic edifices4. Oceanic tholeiitic basalt differs from alkali basalt and continental tholeiite chiefly in having a relatively low percentage of K2O (0.2 weight per cent)4. Some authors have speculated that this type of tholeiitic basalt is the major extrusion from the upper mantle and constitutes the predominant rock type in the upper oceanic crust. ?? 1969 Nature Publishing Group.

  10. The boron and lithium isotopic composition of mid-ocean ridge basalts and the mantle

    Science.gov (United States)

    Marschall, Horst R.; Wanless, V. Dorsey; Shimizu, Nobumichi; Pogge von Strandmann, Philip A. E.; Elliott, Tim; Monteleone, Brian D.

    2017-06-01

    A global selection of 56 mid-ocean ridge basalt (MORB) glasses were analysed for Li and B abundances and isotopic compositions. Analytical accuracy and precision of analyses constitute an improvement over previously published MORB data and allow a more detailed discussion of the Li and B systematics of the crust-mantle system. Refined estimates for primitive mantle abundances ([ Li ] = 1.39 ± 0.10 μg/g and [ B ] = 0.19 ± 0.02 μg/g) and depleted mantle abundances ([ Li ] = 1.20 ± 0.10 μg/g and [ B ] = 0.077 ± 0.010 μg/g) are presented based on mass balance and on partial melting models that utilise observed element ratios in MORB. Assimilation of seawater (or brine) or seawater-altered material beneath the ridge, identified by high Cl / K , causes significant elevation of MORB δ11 B and variable elevation in δ7 Li . The B isotope ratio is, hence, identified as a reliable indicator of assimilation in MORB and values higher than -6‰ are strongly indicative of shallow contamination of the magma. The global set of samples investigated here were produced at various degrees of partial melting and include depleted and enriched MORB from slow and fast-spreading ridge segments with a range of radiogenic isotope signatures and trace element compositions. Uncontaminated (low- Cl / K) MORB show no significant boron isotope variation at the current level of analytical precision, and hence a homogenous B isotopic composition of δ11 B = - 7.1 ± 0.9 ‰ (mean of six ridge segments; 2SD). Boron isotope fractionation during mantle melting and basalt fractionation likely is small, and this δ11 B value reflects the B isotopic composition of the depleted mantle and the bulk silicate Earth, probably within ±0.4‰. Our sample set shows a mean δ7 Li = + 3.5 ± 1.0 ‰ (mean of five ridge segments; 2SD), excluding high- Cl / K samples. A significant variation of 1.0-1.5‰ exists among various ridge segments and among samples within individual ridge segments, but this

  11. Foam Glass for Construction Materials

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund

    2016-01-01

    in a solid foam glass. The foam glass industry employs a range of different melt precursors and foaming agents. Recycle glass is key melt precursors. Many parameters influence the foaming process and optimising the foaming conditions is very time consuming. The most challenging and attractive goal is to make...... the foaming process for foam glass with closed pores. In addition, it is shown that melt foaming should preferably be performed in a viscosity limited regime. Finally, it is suggested that the foaming agent contributes significantly to the solid conductivity of foam glass....

  12. Mineralogy, Petrology and Oxygen Fugacity of the LaPaz Icefield Lunar Basaltic Meteorites and the Origin of Evolved Lunar Basalts

    Science.gov (United States)

    Collins, S. J.; Righter, K.; Brandon, A. D.

    2005-01-01

    LAP 02205 is a 1.2 kg lunar mare basalt meteorite found in the Lap Paz ice field of Antarctica in 2002 [1]. Four similar meteorites were also found within the same region [1] and all five have a combined mass of 1.9 kg (LAP 02224, LAP 02226, LAP 02436 and LAP 03632, hereafter called the LAP meteorites). The LAP meteorites all contain a similar texture, mineral assemblage, and composition. A lunar origin for these samples comes from O isotopic data for LAP 02205 [1], Fe/Mn ratios of pyroxenes [1-5], and the presence of distinct lunar mineralogy such as Fe metal and baddeleyite. The LAP meteorites may represent an area of the Moon, which has never been sampled by Apollo missions, or by other lunar meteorites. The data from this study will be used to compare the LAP meteorites to Apollo mare basalts and lunar basaltic meteorites, and will ultimately help to constrain their origin.

  13. Similarities in Chemistry of North Gorda Ridge basalts with Ultra-slow Spreading Ridge Lavas Due to Decreasing Magma Supply

    Science.gov (United States)

    Davis, A. S.; Clague, D. A.; Paduan, J. B.

    2006-12-01

    Chemical variability of MORB has been reported from ultra-fast to ultra-slow spreading ridges. Despite the large number of studies, high density of precisely located samples is still rare for most ridge segments. Using MBARI's ROV Tiburon and a rock corer, we collected 71 basalt glasses along the axial valley of the 65 km- long, northern Gorda Ridge segment. To explore the temporal variability at the central part of the segment, we collected an additional twenty samples over a distance of 4 km up the eastern valley wall, corresponding to a maximum age of about 150, 000 years. Lava compositions along the ridge axis show considerable major-and minor element diversity (MgO 8.4-4.4%, K2O 0.07-0.36%) for lavas erupted in close proximity. Although they form a near-continuum, the compositions can be separated into two groups, one is typical N-MORB (K2O/TiO2 0.09). The chondrite-normalized REE patterns also reflect this grouping with Ce/YbN 20 for N- MORB and Ce/YbN >1 and Zr/Nb ridge segment, nearly as much diversity exists at the deepest part (>3,800 m) near the non-transform offset at the southern end. Except for two more enriched compositions, off-axis samples are LREE-depleted N-MORB with a narrow compositional range (MgO 7.7±0.3%, Zr/Nb=38-50). In comparison, basalts from the southern Cleft segment of the Juan de Fuca Ridge, which has a comparable spreading rate but different ridge morphology, all plot on the N-MORB trend with high Zr/Nb (30-40) and slight LREE depletion (Smith et al. 1994). In contrast, ultra-slow spreading ridges like Knipovich, Gakkel, and Mohns, with ridge morphologies similar to North Gorda although reaching even greater depth (>4000m), have erupted predominantly E-MORB. Their least enriched compositions overlap with the most LREE-enriched North Gorda lava although most have Zr/Nb1.0 and up to 3.2 (e.g. Haase et al., 1996; Muhe et al., 1997, Hellevang and Pedersen, 2005). On a Zr/Nb versus K2O /TiO2 plot, the basalts from the ultra-slow ridges

  14. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  15. The borosilicate glass for 'PAMELA'

    International Nuclear Information System (INIS)

    Schiewer, E.

    1986-01-01

    The low enriched waste concentrate (LEWC) stored at Mol, Belgium, will be solidified in the vitrification plant 'PAMELA'. An alkali-borosilicate glass was developed by the Hahn-Meitner-Institut, Berlin, which dissolves (11 +- 3)wt% waste oxides while providing sufficient flexibility for changes in the process parameters. The development of the glass labelled SM513LW11 is described. Important properties of the glass melt (viscosity, resistivity, formation of yellow phase) and of the glass (corrosion in aqueous solutions, crystallization) are reported. The corrosion data of this glass are similar to those of other HLW-glasses. Less than five wt% of crystalline material are produced upon cooling of large glass blocks. Crystallization does not affect the chemical durability. (Auth.)

  16. Iron Phosphate Glass-ceramics

    Directory of Open Access Journals (Sweden)

    Andrea Moguš-Milanković

    2015-12-01

    Full Text Available The crystallization of 40Fe2O3-60P2O5, 10ZnO-30Fe2O3-60P2O5 and (43.3−xPbO–(13.7+xFe2O3–43P2O5, (0 x < 30, glasses and glass-ceramic have been investigated. The structural evolution of glasses during heat treatment at various temperatures and the tendency for crystallization for series of glasses with modified composition are characterized by a dendrite-like phase separation in the early stage of crystallization. Such a behavior leads to the formation of randomly dispersed agglomerates which contain the anhedrally shaped crystallites embedded in glass matrix. Therefore, regardless of the type of crystallization, controlled or spontaneous, the formation of crystalline phases in these phosphate glasses and glass-ceramics is attributed to the disordered interfaces between crystalline grains and glassy matrix.

  17. Underground engineering at the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1987-01-01

    A special task group was organized by the US National Committee for Rock Mechanics and the Board on Radioactive Waste Management of the National Research Council to address issues relating to the geotechnical site characterization program for an underground facility to house high-level radioactive waste of the Basalt Waste Isolation Project (BWIP). Intended to provide an overview of the geotechnical program, the study was carried out by a task group consisting of ten members with expertise in the many disciplines required to successfully complete such a project. The task group recognized from the outset that the short time frame of this study would limit its ability to address all geotechnical issues in detail. Geotechnical issues were considered to range from specific technical aspects such as in-situ testing for rock mass permeability; rock hardness testing in the laboratory; or geologic characterizations and quantification of joints, to broader aspects of design philosophy, data collection, and treatment of uncertainty. The task group chose to focus on the broader aspects of underground design and construction, recognizing that the BWIP program utilizes a peer review group on a regular basis which reviews the specific technical questions related to geotechnical engineering. In this way, it was hoped that the review provided by the task group would complement those prepared by the BWIP peer review group

  18. Petrology of basaltic and monomineralic soil fragments from the Sea of Fertility.

    Science.gov (United States)

    Bence, A. E.; Holzwarth, W.; Papike, J. J.

    1972-01-01

    Basaltic and monomineralic fragments from the 150-425 micron size fractions of the Luna 16 core obtained from the Sea of Fertility were studied by optical petrographic, electron microprobe, and single-crystal X-ray diffraction techniques. Three textural varieties were identified in the basalts (intersertal, subophitic, and recrystallized). These textures, the assemblages, and individual mineral compositions (especially pyroxenes) indicate that these basalts crystallized under conditions very similar to those from Apollo 11. The pyroxenes have slightly lower Ti/Al (atomic) ratios than the Apollo 11 pyroxenes. We interpret the presence of octahedral Al as being due to the low TiO2/Al2O3 (weight %) ratio in the bulk rock. All observations made on the fine-grained basalt fragments are consistent with a rapid, near-surface, one-stage crystallization history.

  19. Basalt Related to Lunar Mg-Suite Plutonic Rocks: A Fragment in Lunar Meteorite ALH 81005

    Science.gov (United States)

    Treiman, A. H.; Gross, J.

    2013-09-01

    We report on a basalt clast, in meteorite ALH 81005, which appears to be from a volcanic equivalent of an Mg-suite plutonic rock. Its mineral compositions, mineral proportions, and trace minerals are like those of Mg-norites.

  20. Basalt microlapilli in deep sea sediments of Indian Ocean in the vicinity of Vityaz fracture zone

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Iyer, S.D

    Two cores recovered from the flanks of Mid-India oceanic ridge in the vicinity of Vityaz fracture zone consist of discrete pyroclastic layers at various depths. These layers are composed of coarse-grained, angular basaltic microlapilli in which...

  1. Coupled geomechanical/hydrological modeling: an overview of basalt waste isolation project studies

    International Nuclear Information System (INIS)

    Baca, R.G.; Case, J.B.; Patricio, J.G.

    1980-07-01

    Basalt Waste Isolation Project investigations of the Columbia River basalts are multi-disciplinary in nature with a broad scope spanning such areas as geology, seismology, geochemistry, hydrology, rock mechanics, and many other disciplines as well. In this paper, an overview is presented which surveys recent work on numerical modeling of geomechanical and hydrological processes in a basalt rock environment. A major objective of the ongoing numerical modeling work is to establish a predictive technology base with which to: interpret the interrelationships between geomechanical behavior of rock media, the natural hydrologic phenomena, and repository conditions; evaluate the effectiveness of preconceptual repository designs and assist in the design of in situ field testing; and assess the waste isolation capability of candidate host rocks within the Columbia River basalts. To accomplish this objective, a systems approach has been adopted which is based on the use of digital simulation models

  2. Oxygen fugacity of basaltic magmas and the role of gas-forming elements

    Science.gov (United States)

    Sato, M.

    1978-01-01

    It is suggested that major variations in the relative oxygen fugacity of a basaltic magma are caused primarily by gas-forming elements, especially carbon and hydrogen. According to this theory, carbon, present in the source region of a basaltic magma, reduces the host magma during ascent, as isothermally carbon becomes more reducing with decreasing pressure. For an anhydrous magma such as lunar basalts, this reduction continues through the extrusive phase and the relative oxygen fugacity decreases rapidly until buffered by the precipitation of a metallic phase. For hydrous magmas such as terrestrial basalts, reduction by carbon is eventually superceded by oxidation due to loss of H2 generated by the reaction of C with H2O and by thermal dissociation of H2O. The relative oxygen fugacity of a hydrous magma initially decreases as a magma ascends from the source region and then increases until magnetite crystallization curbs the rising trend of the relative oxygen fugacity.

  3. Some aspects of the minor element chemistry of lunar mare basalts

    International Nuclear Information System (INIS)

    Ringwood, A.E.

    1975-01-01

    The principal minor element (including Ti) characteristics of mare basalts which must be explained by an acceptable theory of petrogenesis are reviewed. Recent hypotheses have proposed that mare basalts formed by equilibrium partial melting of pyroxene-rich cumulates which underlay and were complementary to the anorthositic crust. These hypotheses are examined in detail and are rejected on several grounds. A new hypothesis based upon partial melting under conditions of surface or local equilibrium is proposed. It is assumed that the moon accreted from material which had ultimately formed by fractional condensation from a gas phase of appropriate composition. A disequilibrium mineral assemblage with a bulk composition similar to that of the pyroxenite source region of mare basalts as derived from experimental petrological considerations was formed. It is considered that this model is capable of explaining the principal minor element characteristics of mare basalts and is consistent with interpretations of the major element chemistry of their source region based upon experimental petrology. (Auth.)

  4. The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian

    Directory of Open Access Journals (Sweden)

    Daniela Ogrean

    2001-04-01

    Full Text Available The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Timiş district and between 539–958 respectively, in case of the Racoş basalts (Braşov district. There is a certain variation of the hardness within the same sample, in various measurement points, within the theoretical limits of the hardnesses of the pyroxenes and that of the spinels.

  5. A note on sulphide-oxide mineralisation in Carlsberg Ridge basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Pillow basalts from the Carlsberg Ridge at 3 degrees 35'N contain disseminated chalcopyrite, pyrite, and magnetite. The euhedral shape of the pyrite grains indicate them to be early formed and grown unobstructed while magnetite occurs as skeletal...

  6. Mineral chemistry of Carlsberg Ridge basalts at 3 degrees 35'- 3 degrees 41' N

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Banerjee, R.

    (approximately 91 mole %) are few and rarely zoned. The composition of plagioclase and olivine indicate low pressure equilibrium crystallization. The basalts were probably derived through fractional crystallization at shallow depths under low partial melting...

  7. Ambient noise tomography reveals basalt and sub-basalt velocity structure beneath the Faroe Islands, North Atlantic

    Science.gov (United States)

    Sammarco, Carmelo; Cornwell, David G.; Rawlinson, Nicholas

    2017-11-01

    Ambient noise tomography is applied to seismic data recorded by a portable array of seismographs deployed throughout the Faroe Islands in an effort to illuminate basalt sequences of the North Atlantic Igneous Province, as well as underlying sedimentary layers and Precambrian basement. Rayleigh wave empirical Green's functions between all station pairs are extracted from the data via cross-correlation of long-term recordings, with phase weighted stacking implemented to boost signal-to-noise ratio. Dispersion analysis is applied to extract inter-station group travel-times in the period range 0.5-15 s, followed by inversion for period-dependent group velocity maps. Subsequent inversion for 3-D shear wave velocity reveals the presence of significant lateral heterogeneity (up to 25%) in the crust. Main features of the final model include: (i) a near-surface low velocity layer, interpreted to be the Malinstindur Formation, which comprises subaerial compound lava flows with a weathered upper surface; (ii) a sharp velocity increase at the base of the Malinstindur Formation, which may mark a transition to the underlying Beinisvørð Formation, a thick laterally extensive layer of subaerial basalt sheet lobes; (iii) a low velocity layer at 2.5-7.0 km depth beneath the Beinisvørð Formation, which is consistent with hyaloclastites of the Lopra Formation; (iv) an upper basement layer between depths of 5-9 km and characterized by S wave velocities of approximately 3.2 km/s, consistent with low-grade metamorphosed sedimentary rocks; (v) a high velocity basement, with S wave velocities in excess of 3.6 km/s. This likely reflects the presence of a crystalline mid-lower crust of Archaean continental origin. Compared to previous interpretations of the geological structure beneath the Faroe Islands, our new results point to a more structurally complex and laterally heterogeneous crust, and provide constraints which may help to understand how continental fragments are rifted from the

  8. Glasses for Mali

    CERN Multimedia

    PH Department

    2008-01-01

    We are collecting old pairs of glasses to take out to Mali, where they can be re-used by people there. The price for a pair of glasses can often exceed 3 months salary, so they are prohibitively expensive for many people. If you have any old spectacles you can donate, please put them in the special box in the ATLAS secretariat, Bldg.40-4-D01 before the Christmas closure on 19 December so we can take them with us when we leave for Africa at the end of the month. (more details in ATLAS e-news edition of 29 September 2008: http://atlas-service-enews.web.cern.ch/atlas-service-enews/news/news_mali.php) many thanks! Katharine Leney co-driver of the ATLAS car on the Charity Run to Mali

  9. Breaking the glass ceiling.

    Science.gov (United States)

    Lazarus, A

    1997-03-01

    The glass ceiling is a form of organizational bias and discrimination that prevents qualified professionals from achieving positions of top governance and leadership. This article examines glass ceiling barriers that keep physicians from the upper reaches of management. While these factors apply mainly to women and minority physicians in academia, and are attributable to sexual harassment and discrimination, physicians as a class are frequently denied executive management positions. Such denial results from inadequate preparation for a career in health care administration. Important issues in the professional development of physician executives include mentoring, training and education, administrative experience, and cultural and personality factors. All of those must be considered when making the transition from medicine to management.

  10. Perspectives on Ocean Ridge Basalts from the Segment to the Global Scale

    OpenAIRE

    Gale, Allison

    2012-01-01

    This study addresses the influences on ridge basalt chemistry, through analysis of their major and trace element and isotopic composition at scales ranging from individual ridge segments to the entire length of the ridge system. Local-scale studies of basalts along the Mid-Atlantic Ridge shed light on crustal accretion at slow-spreading ridges, and on the nature of plume-ridge interaction in this region. We show that segments must have multiple supplies of magma delivered along their length, ...

  11. The Relative Rates of Secondary Hydration in Basalt and Rhyolite, and the use of δD as a Paleoclimate Indicator: Implications for Paleoenvironmental and Volcanic Degassing Studies

    Science.gov (United States)

    Seligman, A. N.; Bindeman, I. N.

    2014-12-01

    The δD-H2O correlation is important for volcanic degassing and secondary hydration trends. We utilize the caibration of the TC/EA - MAT 253 continuous flow system, which permits us to analyze wt.% H2O and its δD extracted from 1-8 mg of glass with as little as 0.1 wt% H2O. Tephra that has been secondarily hydrated with meteoric water is widely used as a paleoenvironmental tool, but the rate of secondary hydration, the relative amounts of primary magmatic (degassed) and secondary meteoric water, and the retention of primary and secondary δD values are not well understood. To quantify these processes, we use a natural experiment involving dated Holocene tepha in Kamchatka and Oregon. Our research illustrates the drastic difference in hydration rates between silicic (hydrated after ~1.5 ka) and mafic tephra, which is not hydrated in the Holocene (similar to results for submarine volcanic glasses), and andesitic tephra with intermediate degrees of hydration. The 0.05-7.3 ka basaltic scoria from Klyuchevskoy volcano retains ≤0.45 wt.% primary magmatic H2O, with δD values from -99 to -121 ‰. Four other 0.05-7.6 ka basaltic tephra units from Kamchatka with 65 wt.% have higher (1.5 -3.4) wt.% H2O and δD values between -115 - -160 ‰. We interpret the lower δD values and higher water contents (opposite of the magmatic degassing trend) to be a characteristic of secondary hydration in regions of higher latitude such as Kamchatka and Oregon. We are also investigating 7.7 ka Mt. Mazama tephra in Oregon that are known to be fully hydrated and cover nearly 5000 km2 northeast of Crater Lake and range in elevation from ~1.3-1.9 km to understand the δD and δ18O details of the hydrated water's correspondence with local Holocene meteoric waters. In the future, we plan to use a combination of δD in mid-high latitude precipitation to delineate δD-H2O hydration trends to better understand the distinction between primary magmatic and secondary meteoric water in volcanic

  12. Amorphous gauge glass theory

    International Nuclear Information System (INIS)

    Nielsen, H.B.; Bennett, D.L.

    1987-08-01

    Assuming that a lattice gauge theory describes a fundamental attribute of Nature, it should be pointed out that such a theory in the form of a gauge glass is a weaker assumption than a regular lattice model in as much as it is not constrained by the imposition of translational invariance; translational invariance is, however, recovered approximately in the long wavelength or continuum limit. (orig./WL)

  13. Nuclear traces in glass

    International Nuclear Information System (INIS)

    Segovia A, M. de N.

    1978-01-01

    The charged particles produce, in dielectric materials, physical and chemical effects which make evident the damaged zone along the trajectory of the particle. This damaged zone is known as the latent trace. The latent traces can be enlarged by an etching of the detector material. This treatment attacks preferently the zones of the material where the charged particles have penetrated, producing concavities which can be observed through a low magnification optical microscope. These concavities are known as developed traces. In this work we describe the glass characteristics as a detector of the fission fragments traces. In the first chapter we present a summary of the existing basic theories to explain the formation of traces in solids. In the second chapter we describe the etching method used for the traces development. In the following chapters we determine some chatacteristics of the traces formed on the glass, such as: the development optimum time; the diameter variation of the traces and their density according to the temperature variation of the detector; the glass response to a radiation more penetrating than that of the fission fragments; the distribution of the developed traces and the existing relation between this ditribution and the fission fragments of 252 Cf energies. The method which has been used is simple and cheap and can be utilized in laboratories whose resources are limited. The commercial glass which has been employed allows the registration of the fission fragments and subsequently the realization of experiments which involve the counting of the traces as well as the identification of particles. (author)

  14. Polyamorphism in metalic glass.

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, H. W.; Liu, H. Z.; Cheng, Y. Q.; Wen, J.; Lee, P.L.; Luo, W.K.; Shastri, S.D.; Ma, E.; X-Ray Science Division; Johns Hopkins Univ.; Chinese Academy of Sciences

    2007-03-01

    A metal, or an alloy, can often exist in more than one crystal structure. The face-centered-cubic and body-centered-cubic forms of iron (or steel) are a familiar example of such polymorphism. When metallic materials are made in the amorphous form, is a parallel 'polyamorphism' possible? So far, polyamorphic phase transitions in the glassy state have been observed only in glasses involving directional and open (such as tetrahedral) coordination environments. Here, we report an in situ X-ray diffraction observation of a pressure-induced transition between two distinct amorphous polymorphs in a Ce{sub 55}Al{sub 45} metallic glass. The large density difference observed between the two polyamorphs is attributed to their different electronic and atomic structures, in particular the bond shortening revealed by ab initio modeling of the effects of f-electron delocalization. This discovery offers a new perspective of the amorphous state of metals, and has implications for understanding the structure, evolution and properties of metallic glasses and related liquids. Our work also opens a new avenue towards technologically useful amorphous alloys that are compositionally identical but with different thermodynamic, functional and rheological properties due to different bonding and structural characteristics.

  15. Athermal photofluidization of glasses

    Science.gov (United States)

    Fang, G. J.; Maclennan, J. E.; Yi, Y.; Glaser, M. A.; Farrow, M.; Korblova, E.; Walba, D. M.; Furtak, T. E.; Clark, N. A.

    2013-02-01

    Azobenzene and its derivatives are among the most important organic photonic materials, with their photo-induced trans-cis isomerization leading to applications ranging from holographic data storage and photoalignment to photoactuation and nanorobotics. A key element and enduring mystery in the photophysics of azobenzenes, central to all such applications, is athermal photofluidization: illumination that produces only a sub-Kelvin increase in average temperature can reduce, by many orders of magnitude, the viscosity of an organic glassy host at temperatures more than 100 K below its thermal glass transition. Here we analyse the relaxation dynamics of a dense monolayer glass of azobenzene-based molecules to obtain a measurement of the transient local effective temperature at which a photo-isomerizing molecule attacks its orientationally confining barriers. This high temperature (Tloc~800 K) leads directly to photofluidization, as each absorbed photon generates an event in which a local glass transition temperature is exceeded, enabling collective confining barriers to be attacked with near 100% quantum efficiency.

  16. Crystal recycling in the steady-state system of the active Stromboli volcano: a 2.5-ka story inferred from in situ Sr-isotope and trace element data

    Science.gov (United States)

    Francalanci, Lorella; Avanzinelli, Riccardo; Nardini, Isabella; Tiepolo, Massimo; Davidson, Jon P.; Vannucci, Riccardo

    2012-01-01

    In situ Sr-isotope data by microdrilling, coupled with major and trace element analyses, have been performed on plagioclase and clinopyroxene from seven samples collected during the 2002-2003 eruptive crisis at Stromboli volcano (Aeolian Islands, Italy). On 28 December 2002, the persistent moderate explosive activity was broken by an effusive event lasting about 7 months. A more violent explosion (paroxysm) occurred on 5 April 2003. Two magma types were erupted, namely a volatile-poor and highly porphyritic magma (HP-magma) poured out as scoria or lava and a volatile-rich, phenocryst-poor magma (LP-magma) found as pumice. LP-magma differs from the HP-magma also for its slightly less-evolved chemistry, the groundmass composition and the lower Sr-isotope ratios. Micro-Sr-isotope data show the presence of zoned minerals in strong isotope disequilibrium, as previously found in products erupted in 1984, 1985 and 1996 AD, with 87Sr/86Sr values generally decreasing from cores to rims of minerals. Only some outer rims testify for equilibrium with the host groundmass. The internal mineral zones with high Sr-isotope ratios (0.70665-0.70618) are interpreted as `antecrysts', crystallised during the previous activity and recycled in the present-day system since the opening shoshonitic activity of the Recent Period, which occurred at about 2.5 ka ago. This result has implications for the dynamics of the present-day plumbing system of Stromboli at intermediate pressure (about 2-3 km depth) and allows us to propose a model whereby an HP-magma reservoir is directly interconnected at the bottom with a cumulate crystal much reservoir. Efficient mixing between residing HP- and input LP-magmas can occur in this reservoir, due to more similar rheological characteristics of the two magmas than in the conduit, where crystallisation is enhanced by degassing. Antecrysts (and possibly melts) re-enter in the HP-magma reservoir both from the bottom, recycled by ascending LP-magmas crossing the

  17. Mineralogy, geochemistry and expansion testing of an alkali-reactive basalt from western Anatolia, Turkey

    International Nuclear Information System (INIS)

    Copuroglu, Oguzhan; Andic-Cakir, Ozge; Broekmans, Maarten A.T.M.; Kuehnel, Radko

    2009-01-01

    In this paper, the alkali-silica reaction performance of a basalt rock from western Anatolia, Turkey is reported. It is observed that the rock causes severe gel formation in the concrete microbar test. It appears that the main source of expansion is the reactive glassy phase of the basalt matrix having approximately 70% of SiO 2 . The study presents the microstructural characteristics of unreacted and reacted basalt aggregate by optical and electron microscopy and discusses the possible reaction mechanism. Microstructural analysis revealed that the dissolution of silica is overwhelming in the matrix of the basalt and it eventually generates four consequences: (1) Formation of alkali-silica reaction gel at the aggregate perimeter, (2) increased porosity and permeability of the basalt matrix, (3) reduction of mechanical properties of the aggregate and (4) additional gel formation within the aggregate. It is concluded that the basalt rock is highly prone to alkali-silica reaction. As an aggregate, this rock is not suitable for concrete production.

  18. Helium behaviour in nuclear glasses

    International Nuclear Information System (INIS)

    Fares, T.

    2011-01-01

    The present thesis focuses on the study of helium behavior in R7T7 nuclear waste glass. Helium is generated by the minor actinides alpha decays incorporated in the glass matrix. Therefore, four types of materials were used in this work. These are non radioactive R7T7 glasses saturated with helium under pressure, glasses implanted with 3 He + ions, glasses doped with curium and glasses irradiated in nuclear reactor. The study of helium solubility in saturated R7T7 glass has shown that helium atoms are inserted in the glass free volume. The results yielded a solubility of about 10 16 at. cm -3 atm. -1 . The incorporation limit of helium in this type of glass has been determined; its value amounted to about 2*10 21 at. cm -3 , corresponding to 2.5 at.%. Diffusion studies have shown that the helium migration is controlled by the single population dissolved in the glass free volume. An ideal diffusion model was used to simulate the helium release data which allowed to determine diffusion coefficients obeying to the following Arrhenius law: D = D 0 exp(-E a /kBT), where D 0 = 2.2*10 -2 and 5.4*10 -3 cm 2 s -1 and E a = 0.61 eV for the helium saturated and the curium doped glass respectively. These results reflect a thermally activated diffusion mechanism which seems to be not influenced by the glass radiation damage and helium concentrations studied in the present work (up to 8*10 19 at. g -1 , corresponding to 0.1 at.%). Characterizations of the macroscopic, structural and microstructural properties of glasses irradiated in nuclear reactor did not reveal any impact associated with the presence of helium at high concentrations. The observed modifications i.e. a swelling of 0.7 %, a decrease in hardness by 38 %, an increase between 8 and 34 % of the fracture toughness and a stabilization of the glass structure under irradiation, were attributed to the glass nuclear damage induced by the irradiation in reactor. Characterizations by SEM and TEM of R7T7 glasses implanted

  19. Insights into Earth's Accretion and Mantle Structure from Neon and Xenon in Icelandic Basalt (Invited)

    Science.gov (United States)

    Mukhopadhyay, S.

    2010-12-01

    The noble gases provide important constraints for planet accretion models and understanding mantle structure and dynamics. Recent work based on continental well gases indicate that the MORB source 20Ne/22Ne ratio is similar to the Ne-B component in chondrites [1,2]. However, ratios higher than Ne-B have been reported in plume-derived Devonian rocks form the Kola Peninsula [3]. Here I report high-precision noble gas data in an Icelandic basaltic glass that demonstrate plumes have a different 20Ne/22Ne ratio than the MORB source. The highest measured 20Ne/22Ne ratio from Iceland is ~12.9, very similar to values in the Kola plume, but quite distinct from the convecting upper mantle as constrained from the well gases [1,2]. Hence, the Icelandic and Kola plume data indicate that OIBs and MORBs have different 20Ne/22Ne ratios. Since 20Ne/22Ne ratios in the mantle cannot change, Earth must have accreted volatiles from at least two separate reservoirs. The differences in 20Ne/22Ne ratios between OIBs and MORBs further indicate that early heterogeneities in the Earth’s mantle have not been wiped away by 4.5 Gyrs of mantle convection, placing strong constraints on mixing and mass flow in the mantle. The requirement of limited direct mixing between plumes and MORB source is supported by 129Xe, formed through radioactive decay of now extinct 129I. Combined He, Ne, and Xe measurements demonstrate that the Iceland plume has a lower 129Xe/130Xe ratio than MORBs because it evolved with a I/Xe ratio distinct from the MORB source and not because of recycled atmosphere (which has low 129/130Xe) in the plume source. Since 129I became extinct 80 Myrs after solar system formation, limited mixing between plume and MORB source is a stringent requirement. Additionally, the high-precision Xe measurements reveal for the first time that the Iceland plume source has significantly higher proportion of plutonium derived fission xenon than MORBs, requiring the plume source to be less degassed

  20. Structural Behavior of Concrete Beams Reinforced with Basalt Fiber Reinforced Polymer (BFRP) Bars

    Science.gov (United States)

    Ovitigala, Thilan

    The main challenge for civil engineers is to provide sustainable, environmentally friendly and financially feasible structures to the society. Finding new materials such as fiber reinforced polymer (FRP) material that can fulfill the above requirements is a must. FRP material was expensive and it was limited to niche markets such as space shuttles and air industry in the 1960s. Over the time, it became cheaper and spread to other industries such as sporting goods in the 1980-1990, and then towards the infrastructure industry. Design and construction guidelines are available for carbon fiber reinforced polymer (CFRP), aramid fiber reinforced polymer (AFRP) and glass fiber reinforced polymer (GFRP) and they are currently used in structural applications. Since FRP is linear elastic brittle material, design guidelines for the steel reinforcement are not valid for FRP materials. Corrosion of steel reinforcement affects the durability of the concrete structures. FRP reinforcement is identified as an alternative to steel reinforcement in corrosive environments. Although basalt fiber reinforced polymer (BFRP) has many advantages over other FRP materials, but limited studies have been done. These studies didn't include larger BFRP bar diameters that are mostly used in practice. Therefore, larger beam sizes with larger BFRP reinforcement bar diameters are needed to investigate the flexural and shear behavior of BFRP reinforced concrete beams. Also, shear behavior of BFRP reinforced concrete beams was not yet studied. Experimental testing of mechanical properties and bond strength of BFRP bars and flexural and shear behavior of BFRP reinforced concrete beams are needed to include BFRP reinforcement bars in the design codes. This study mainly focuses on the use of BFRP bars as internal reinforcement. The test results of the mechanical properties of BFRP reinforcement bars, the bond strength of BFRP reinforcement bars, and the flexural and shear behavior of concrete beams

  1. Transferability of glass lens molding

    Science.gov (United States)

    Katsuki, Masahide

    2006-02-01

    Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

  2. Analytical Plan for Roman Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Buck, Edgar C.; Mueller, Karl T.; Schwantes, Jon M.; Olszta, Matthew J.; Thevuthasan, Suntharampillai; Heeren, Ronald M.

    2011-01-01

    Roman glasses that have been in the sea or underground for about 1800 years can serve as the independent “experiment” that is needed for validation of codes and models that are used in performance assessment. Two sets of Roman-era glasses have been obtained for this purpose. One set comes from the sunken vessel the Iulia Felix; the second from recently excavated glasses from a Roman villa in Aquileia, Italy. The specimens contain glass artifacts and attached sediment or soil. In the case of the Iulia Felix glasses quite a lot of analytical work has been completed at the University of Padova, but from an archaeological perspective. The glasses from Aquileia have not been so carefully analyzed, but they are similar to other Roman glasses. Both glass and sediment or soil need to be analyzed and are the subject of this analytical plan. The glasses need to be analyzed with the goal of validating the model used to describe glass dissolution. The sediment and soil need to be analyzed to determine the profile of elements released from the glass. This latter need represents a significant analytical challenge because of the trace quantities that need to be analyzed. Both pieces of information will yield important information useful in the validation of the glass dissolution model and the chemical transport code(s) used to determine the migration of elements once released from the glass. In this plan, we outline the analytical techniques that should be useful in obtaining the needed information and suggest a useful starting point for this analytical effort.

  3. The investigation of gamma and neutron shielding properties of concrete including basalt fibre for nuclear energy applications

    International Nuclear Information System (INIS)

    Nulk, H.; Ipbuker, C.; Gulik, V.; Tkaczyk, A.; Biland, A.

    2015-01-01

    In this study, we would like to draw attention to the prospect of basalt fibre as the main component for concrete reinforcement of NPP. This work describes the computational study of gamma attenuation parameters, the effective atomic number Z(eff) and the effective electron density N e (eff), of relatively light-weight concrete with chopped basalt fibre used as reinforcement in different mixture rates. We can draw the following conclusions. Basalt fibre is a relatively cheap material that can be used as reinforcement instead of metallic fibers. Basalt fibre has a similar specific gravity to that of concrete elements. Basalt fibre has high chemical and abrasion resistance. Basalt fibre has almost 10 times the tensile strength of steel re-bars. Gamma-ray attenuation coefficients increase with addition of basalt fibre into concrete in every case. The effective atomic number of the concrete increases with the addition of basalt fibre. The results show that basalt fibre reinforced concrete have improved shielding properties against gamma rays in comparison with regular concrete. This result is based on a regular concrete with only basalt fiber reinforcement. We estimate that with addition of standard aggregates for radiation shielding concrete, such as barite, magnetite or hematite, the shielding properties will increase exponentially

  4. Foam Glass Production from Waste Glass by Compression

    Science.gov (United States)

    Khamidulina, D. D.; Nekrasova, S. A.; Voronin, K. M.

    2017-11-01

    The authors have identified the impact of the glass mixture briquetting process parameters (milling method, dispersibility, particle size distribution, particle form and compression parameters) on the performance characteristics and the physical and chemical properties of foam glass. It was demonstrated that briquette density increasing contributes to achieving a lower average density of foam glass. It was proven that briquettes produced from multifractional powders are characterized by a higher density than those produced from powders with a limited range of particle size distribution.

  5. Calcites from Ocean Crust Basalts: Reliable Proxy Archives?

    Science.gov (United States)

    Böhm, Florian; Eisenhauer, Anton

    2017-04-01

    Calcite cements in ocean crust basalts of the deep sea form from mixtures of cold seawater and warm hydrothermal fluids (about 0-70°C). These low temperature alteration (LTA) calcites have recently gained new interest as proxy recorders of seawater composition (Refs. 1-5). Recent LTA calcite reconstructions of the Sr/Ca and Mg/Ca evolution in ocean waters point to considerably lower Sr/Ca and Mg/Ca ratios during the Cretaceous and Paleogene than in the modern ocean. However, diagenetic alteration in contact with the basalt host rock may change the composition of the LTA calcites. For testing the reliability of LTA calcite records of seawater composition multi-proxy approaches are applied: oxygen isotopes indicate precipitation temperatures, strontium isotopes (87Sr/86Sr) and trace elements indicate influences from hydrothermal fluids. Additional information about the influence of basement rocks on LTA calcite composition can be derived from analyses of stable calcium and strontium isotopes (44/40Ca, 88/86Sr). We find low 44/40Ca values for DSDP and ODP sites where the 87Sr/86Sr ratios of LTA calcites indicate basement influence. On the other hand, for some sites the 87Sr/86Sr values inidicate precipitation from pristine seawater, while low 44/40Ca values indicate basement influence. All of these sites are either older than 50 Myr or show calcite precipitation temperatures >50°C. Sites that are younger than 25 Myr and had formation temperatures 50°C significantly higher 88/86Sr values were observed. The calcium isotope results indicate basement influence on LTA calcite composition at temperatures >10°C. Radiogenic strontium isotopes, in contrast, can be used as unequivocal basement influence indicators only at temperatures above 30°C. Below about 20°C 87Sr/86Sr ratios are no reliable indicators of basement influence. All LTA calcites of sites older than 50 Myr formed (or recrystallized) at temperatures >15°C. Low 44/40Ca values indicate that

  6. Influence of Glass Property Restrictions on Hanford HLW Glass Volume

    International Nuclear Information System (INIS)

    Kim, Dong-Sang; Vienna, John D.

    2001-01-01

    A systematic evaluation of Hanford High-Level Waste (HLW) loading in alkali-alumino-borosilicate glasses was performed. The waste feed compositions used were obtained from current tank waste composition estimates, Hanford's baseline retrieval sequence, and pretreatment processes. The waste feeds were sorted into groups of like composition by cluster analysis. Glass composition optimization was performed on each cluster to meet property and composition constraints while maximizing waste loading. Glass properties were estimated using property models developed for Hanford HLW glasses. The impacts of many constraints on the volume of HLW glass to be produced at Hanford were evaluated. The liquidus temperature, melting temperature, chromium concentration, formation of multiple phases on cooling, and product consistency test response requirements for the glass were varied one- or many-at-a-time and the resultant glass volume was calculated. This study shows clearly that the allowance of crystalline phases in the glass melter can significantly decrease the volume of HLW glass to be produced at Hanford.

  7. Mechanical failure and glass transition in metallic glasses

    International Nuclear Information System (INIS)

    Egami, T.

    2011-01-01

    Research highlights: → We review the recent results of molecular dynamics simulations on metallic glasses. → They show the equivalence of mechanical failure and glass transition. → We discuss the microscopic mechanism behind this equivalence. → We show that the density of defects in metallic glasses is as high as a quarter. → Our concepts about the defect state in glasses need to be changed. - Abstract: The current majority view on the phenomenon of mechanical failure in metallic glasses appears to be that it is caused by the activity of some structural defects, such as free-volumes or shear transformation zones, and the concentration of such defects is small, only of the order of 1%. However, the recent results compel us to revise this view. Through molecular dynamics simulation it has been shown that mechanical failure is the stress-induced glass transition. According to our theory the concentration of the liquid-like sites (defects) is well over 20% at the glass transition. We suggest that the defect concentration in metallic glasses is actually very high, and percolation of such defects causes atomic avalanche and mechanical failure. In this article we discuss the glass transition, mechanical failure and viscosity from such a point of view.

  8. Like a cannonball: origin of dense spherical basaltic ejecta

    Science.gov (United States)

    Di Piazza, Andrea; Del Bello, Elisabetta; Mollo, Silvio; Vona, Alessandro; Alvarado, Guillermo E.; Masotta, Matteo

    2017-05-01

    Cannonballs are rare spherical to sub-spherical eruptive products associated with basaltic explosive activity. The origin of cannonballs is still debated and subjected to a wide spectrum of different interpretations. In order to better understand the physicochemical mechanisms controlling the formation of these explosive products, we investigated the textural and chemical features of cannonballs from the Cerro Chopo monogenetic volcano (Costa Rica). These explosive products ubiquitously show a core domain with coalesced bubbles (30-36% porosity) wrapped in a dense rim domain with small, isolated bubbles (20-27% porosity). Both domains are identical in terms of bulk rock composition and mineral chemistry and are portions of the same magma batch. Results from combined petrological and thermodynamic modeling indicate that a low-viscosity ( 20 Pa s) melt containing early-formed olivine phenocrysts ( 9 vol.%) ascended from storage at a decompression rate of 0.5 MPa s-1 until it reached a depth of 4.5 km (equivalent to a pressure of 150 MPa). While rising from depth to 4.5 km, the melt underwent rapid decompression (0.5-2.6 MPa s-1) and H2O exsolution, driving late-stage crystallization of the groundmass. The fast ascent velocity (21-110 m s-1) while rising between 4.5 km and the surface induced turbulent (Re >103), annular flow development in the uppermost region of the conduit. We propose that cannonballs represent blebs of fluid magmas that underwent shear-driven detachment from the annulus of magma lining the conduit walls at depths lower than 4.5 km. The formation of such cannonballs is dictated by magma transport dynamics of low-viscosity, phenocryst-poor, and volatile-rich melts that rapidly accelerate within the shallow conduit.

  9. Analysis of glass fibre sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2014-01-01

    surfaces are called sizing. The sizing influences the properties of the interface between fibres and a matrix, and subsequently affects mechanical properties of composites. In this work the sizing of commercially available glass fibres was analysed so as to study the composition and chemical structures......Glass fibre reinforced polymer composites are widely used for industrial and engineering applications which include construction, aerospace, automotive and wind energy industry. During the manufacturing glass fibres, they are surface-treated with an aqueous solution. This process and the treated....... Soxhlet extraction was used to extract components of the sizing from the glass fibres. The glass fibres, their extracts and coated glass plates were analysed by Thermo-Gravimetric Analysis combined with a mass spectrometer (TGA-MS), and Attenuated Total Reflectance Fourier Transform Infrared (ATR...

  10. Relaxation Pathways in Metallic Glasses

    Science.gov (United States)

    Gallino, Isabella; Busch, Ralf

    2017-11-01

    At temperatures below the glass transition temperature, physical properties of metallic glasses, such as density, viscosity, electrical resistivity or enthalpy, slowly evolve with time. This is the process of physical aging that occurs among all types of glasses and leads to structural changes at the microscopic level. Even though the relaxation pathways are ruled by thermodynamics as the glass attempts to re-attain thermodynamic equilibrium, they are steered by sluggish kinetics at the microscopic level. Understanding the structural and dynamic pathways of the relaxing glassy state is still one of the grand challenges in materials physics. We review some of the recent experimental advances made in understanding the nature of the relaxation phenomenon in metallic glasses and its implications to the macroscopic and microscopic properties changes of the relaxing glass.

  11. Crystallization of bismuth borate glasses

    International Nuclear Information System (INIS)

    Bajaj, Anu; Khanna, Atul

    2009-01-01

    Bismuth borate glasses with Bi 2 O 3 concentration of 20-66 mol% were prepared by melt quenching and devitrified by heat treatment above their glass transition temperatures. All glasses show a strong tendency towards crystallization on annealing that increases with Bi 2 O 3 concentration. The crystalline phases formed on devitrification were characterized by FTIR absorption spectroscopy and DSC measurements. Our studies reveal that phases produced in glasses are strongly determined by initial glass composition and the two most stable crystalline phases are: Bi 3 B 5 O 12 and Bi 4 B 2 O 9 . The metastable BiBO 3 phase can also be formed by devitrification of glass with 50 mol% of Bi 2 O 3 . This phase is, however, unstable and decomposes into Bi 3 B 5 O 12 and Bi 4 B 2 O 9 on prolonged heat treatment.

  12. Structural color from colloidal glasses

    Science.gov (United States)

    Magkiriadou, Sofia

    When a material has inhomogeneities at a lengthscale comparable to the wavelength of light, interference can give rise to structural colors: colors that originate from the interaction of the material's microstructure with light and do not require absorbing dyes. In this thesis we study a class of these materials, called photonic glasses, where the inhomogeneities form a dense and random arrangement. Photonic glasses have angle-independent structural colors that look like those of conventional dyes. However, when this work started, there was only a handful of colors accessible with photonic glasses, mostly hues of blue. We use various types of colloidal particles to make photonic glasses, and we study, both theoretically and experimentally, how the optical properties of these glasses relate to their structure and constituent particles. Based on our observations from glasses of conventional particles, we construct a theoretical model that explains the scarcity of yellow, orange, and red photonic glasses. Guided by this model, we develop novel colloidal systems that allow a higher degree of control over structural color. We assemble glasses of soft, core-shell particles with scattering cores and transparent shells, where the resonant wavelength can be tuned independently of the reflectivity. We then encapsulate glasses of these core-shell particles into emulsion droplets of tunable size; in this system, we observe, for the first time, angle-independent structural colors that cover the entire visible spectrum. To enhance color saturation, we begin experimenting with inverse glasses, where the refractive index of the particles is lower than the refractive index of the medium, with promising results. Finally, based on our theoretical model for scattering from colloidal glasses, we begin an exploration of the color gamut that could be achieved with this technique, and we find that photonic glasses are a promising approach to a new type of long-lasting, non-toxic, and

  13. PLZT capacitor on glass substrate

    Science.gov (United States)

    Fairchild, M. Ray; Taylor, Ralph S.; Berlin, Carl W.; Wong, Celine W. K.; Ma, Beihai; Balachandran, Uthamalingam

    2016-01-05

    A lead-lanthanum-zirconium-titanate (PLZT) capacitor on a substrate formed of glass. The first metallization layer is deposited on a top side of the substrate to form a first electrode. The dielectric layer of PLZT is deposited over the first metallization layer. The second metallization layer deposited over the dielectric layer to form a second electrode. The glass substrate is advantageous as glass is compatible with an annealing process used to form the capacitor.

  14. Who will buy smart glasses?

    DEFF Research Database (Denmark)

    Rauschnabel, Philipp; Brem, Alexander; Ivens, Bjørn S.

    2015-01-01

    of research that investigates the role of personality in predicting media usage by analyzing smart glasses, particularly Google Glass. First, we integrate AR devices into the current evolution of media and technologies. Then, we draw on the Big Five Model of human personality and present the results from two...... studies that investigate the direct and moderating effects of human personality on the awareness and innovation adoption of smart glasses. Our results show that open and emotionally stable consumers tend to be more aware of Google Glass. Consumers who perceive the potential for high functional benefits...

  15. Halide laser glasses

    Energy Technology Data Exchange (ETDEWEB)

    Weber, M.J.

    1982-01-14

    Energy storage and energy extraction are of prime importance for efficient laser action and are affected by the line strengths and linewidths of optical transitions, excited-state lifetimes, nonradiative decay processes, spectroscopic inhomogeneities, nonlinear refractive index, and damage threshold. These properties are all host dependent. To illustrate this, the spectroscopic properties of Nd/sup 3 +/ have been measured in numerous oxide, oxyhalide, and halide glasses. A table summarizes the reported ranges of stimulated emission cross sections, peak wavelengths, linewidths, and radiative lifetimes associated with the /sup 4/F/sub 3/2/ ..-->.. /sup 4/I/sub 11/2/ lasing transition.

  16. Exploration of H2O-CO2 Solubility in Alkali Basalt at low-H2O

    Science.gov (United States)

    Roggensack, K.; Allison, C. M.; Clarke, A. B.

    2017-12-01

    A number of recent experimental studies have found conflicting evidence for and against the influence of H2O on CO2 solubility in basalt and alkali-rich mafic magma (e.g. Behrens et al., 2009; Shishkina et al., 2010;2014; Iacono-Marziano et al., 2012). Some of the uncertainty is due to the error with spectroscopic determination (FTIR) of carbon and the challenge of controlling H2O abundance in experiments. It's been widely observed that even experimental capsules without added H2O may produce hydrous glasses containing several wt.% H2O. We conducted fluid-saturated, mixed-fluid (H2O-CO2) experiments to determine the solubility in alkali basalt with particular emphasis on conditions at low-H2O. To limit possible H2O contamination, materials were dried prior to loading and experimental capsules were sealed under vacuum. Experiments were run using a piston-cylinder, in Pt (pre-soaked in Fe) or AuPd capsules and operating at pressures from 400 to 600 MPa. Post-run the capsules were punctured under vacuum and fluids were condensed, separated, and measured by mercury manometry. A comparison between two experiments run at the same temperature and pressure conditions but with different fluid compositions illustrates the correlation between carbonate and H2O solubility. Uncertainties associated with using concentrations calculated from FTIR data can be reduced by directly comparing analyses on wafers of similar thickness. We observe that the experiment with greater H2O absorbance also has a higher carbonate absorbance than the experiment with lower H2O absorbance. Since the experiments were run at the same pressure, the experiment with more water-rich fluid, and higher dissolved H2O, has lower CO2 fugacity, but surprisingly has higher dissolved CO2 content. Overall, the results show two distinct trends. Experiments conducted at low-H2O (0.5 to 0.8 wt.%) show lower dissolved CO2 than those conducted at moderate-H2O (2 to 3 wt.%) at similar CO2 fugacity. These data show that

  17. New Erbium Doped Antimony Glasses for Laser and Glass ...

    African Journals Online (AJOL)

    Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses.

  18. Structural Glass Beams with Embedded Glass Fibre Reinforcement

    NARCIS (Netherlands)

    Louter, P.C.; Leung, Calvin; Kolstein, M.H.; Vambersky, J.N.J.A.; Bos, Freek; Louter, Pieter Christiaan; Veer, Fred

    2010-01-01

    This paper investigates the possibilities of pultruded glass fibre rods as embedded reinforcement in SentryGlas (SG) laminated glass beams. To do so, a series of pullout tests, to investigate the bond strength of the rods to the laminate, and a series of beam tests, to investigate the post-breakage

  19. Restorative Glass : Reversible, discreet restoration using structural glass components

    NARCIS (Netherlands)

    Oikonomopoulou, F.; Bristogianni, T.; Barou, L.; van Hees, R.P.J.; Nijsse, R.; Veer, F.A.; Henk, Schellen; van Schijndel, Jos

    2016-01-01

    The application of structural glass as the principal material in restoration and conservation practices is a distinguishable, yet discreet approach. The transparency of glass allows the simultaneous perception of the monument at both its original and present condition, preserving its historical and

  20. Spherical resonators coated by glass and glass-ceramic films

    Science.gov (United States)

    Ristic, Davor; Chiappini, Andrea; Chiasera, Alessandro; Armellini, Cristina; Carpentiero, Alessandro; Mazzola, Maurizio; Moser, Enrico; Varas, Stefano; Berneschi, Simone; Nunzi Conti, Gualtiero; Pelli, Stefano; Soria, Silvia; Speranza, Giorgio; Lunelli, Lorenzo; Pederzolli, Cecilia; Prudenzano, Francesco; Feron, Patrice; Ivanda, Mile; Cibiel, Gilles; Righini, Giancarlo C.; Ferrari, Maurizio

    2012-02-01

    Coating of spherical microresonators is a very promising technique for optimizing their optical properties. Optical coatings are constituted by glasses, polymer, and glass ceramics, passive or activated by luminescent species, Glass ceramic activated by rare earth ions are nanocomposite systems that exhibit specific morphologic, structural and spectroscopic properties allowing to develop interesting new physical concepts, for instance the mechanism related to the transparency, as well as novel photonic devices based on the enhancement of the luminescence. At the state of art the fabrication techniques based on bottom-up and top-down approaches appear to be viable although a specific effort is required to achieve the necessary reliability and reproducibility of the preparation protocols. In particular, the dependence of the final product on the specific parent glass and on the employed synthesis still remain an important task of the research in material science. Looking to application, the enhanced spectroscopic properties typical of glass ceramic in respect to those of the amorphous structures constitute an important point for the development of integrated optics devices, including coating of spherical microresonators. Here we present a review regarding spherical microresonators coated by glass and glass-ceramic film activated by Er3+ ions. Er3+ ions appear to be embedded in a crystalline or amorphous environment and the lifetime dynamic is influenced by the geometry and by the morphology of the system. Photoluminescence results and morphologic properties are discussed for both amorphous and glass ceramic films.