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Sample records for basaltic micrometeorite expands

  1. A unique basaltic micrometeorite expands the inventory of solar system planetary crusts

    Science.gov (United States)

    Gounelle, Matthieu; Chaussidon, Marc; Morbidelli, Alessandro; Barrat, Jean-Alix; Engrand, Cécile; Zolensky, Michael E.; McKeegan, Kevin D.

    2009-01-01

    Micrometeorites with diameter ≈100–200 μm dominate the flux of extraterrestrial matter on Earth. The vast majority of micrometeorites are chemically, mineralogically, and isotopically related to carbonaceous chondrites, which amount to only 2.5% of meteorite falls. Here, we report the discovery of the first basaltic micrometeorite (MM40). This micrometeorite is unlike any other basalt known in the solar system as revealed by isotopic data, mineral chemistry, and trace element abundances. The discovery of a new basaltic asteroidal surface expands the solar system inventory of planetary crusts and underlines the importance of micrometeorites for sampling the asteroids' surfaces in a way complementary to meteorites, mainly because they do not suffer dynamical biases as meteorites do. The parent asteroid of MM40 has undergone extensive metamorphism, which ended no earlier than 7.9 Myr after solar system formation. Numerical simulations of dust transport dynamics suggest that MM40 might originate from one of the recently discovered basaltic asteroids that are not members of the Vesta family. The ability to retrieve such a wealth of information from this tiny (a few micrograms) sample is auspicious some years before the launch of a Mars sample return mission. PMID:19366660

  2. Artificial_Micrometeorites

    CERN Document Server

    Dolya, S N

    2014-01-01

    An iron ball, a beryllium sphere and a tungsten tube segment with diameter twenty microns, are electrically charged while proton beam irradiating. These bodies are accelerated by the running pulse field in a spiral waveguide up to velocity: thirty kilometers per second. The accelerator, generating micrometeorites is placed at satellites on the Earth orbit. This article considers processes of penetration of micrometeorites into the Earth atmosphere. It is shown that micrometeorites evaporate at the height of one hundred kilometers-one hundred fifty kilometers from the surface of the Earth. A micrometeorite which is a segment of the beryllium tube equipped with a graphite cone in the head part is the very meteorite to reach the Earth surface without being broken.

  3. Search for superconductivity in micrometeorites.

    Science.gov (United States)

    Guénon, S; Ramírez, J G; Basaran, Ali C; Wampler, J; Thiemens, M; Taylor, S; Schuller, Ivan K

    2014-12-05

    We have developed a very sensitive, highly selective, non-destructive technique for screening inhomogeneous materials for the presence of superconductivity. This technique, based on phase sensitive detection of microwave absorption is capable of detecting 10(-12) cc of a superconductor embedded in a non-superconducting, non-magnetic matrix. For the first time, we apply this technique to the search for superconductivity in extraterrestrial samples. We tested approximately 65 micrometeorites collected from the water well at the Amundsen-Scott South pole station and compared their spectra with those of eight reference materials. None of these micrometeorites contained superconducting compounds, but we saw the Verwey transition of magnetite in our microwave system. This demonstrates that we are able to detect electro-magnetic phase transitions in extraterrestrial materials at cryogenic temperatures.

  4. Micrometeorites: Extraterrestrial particulate matter on the earth

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Rudraswami, N.G.

    found to contain some mineral assemblages which do not occur in any meteorite class. Polar collections Since the 1980s, large scale collections have been made in the polar regions – both the Arctic (Greenland) and the Antarctic. It has been... their relation to the known meteorite class. Several recent investigations have been undertaken on the oxygen isotopes of cosmic dust/micrometeorites. Taylor et al. (2005) analysed eight Antarctic micrometeorites for oxygen isotopes. Selection of particles...

  5. Modern and ancient micrometeorites: Experimental and numerical studies

    OpenAIRE

    Briani, Giacomo

    2010-01-01

    Micrometeorites are sub-millimetric extraterrestrial samples, which dominate the flux of extraterrestrial matter entering the Earth atmosphere. Every micrometeorite is altered by the interaction with the atmosphere. However, they can be found embedded in larger meteorites, in which case they are called microxenoliths. Microxenoliths are ancient micrometeorites, and they allow the study of past epochs of the Solar System, not accessible by studying micrometeorites. New microxenoliths have been...

  6. Initial Results from the Kwajalein Micrometeorite Collections

    Science.gov (United States)

    Wozniakiewicz, P. J.; Bradley, J. P.; Price, M. C.; Zolensky, M. E.; Ishii, H. A.; Brownlee, D. E.; Dearborn, D.; Jones, T.; Barnett, B.; Yakuma, S.; Letendre, T.; Gonzalez, C.; Bastien, R.; Rodriquez, M.

    2014-01-01

    Micrometeorites are constantly arriving at the Earth's surface, however, they are quickly diluted by the natural and anthropogenic back-ground dust. The successful collection of micromete-orites requires either the employment of a separation technique (e.g. using magnets to separate metal-bearing micrometeorites from deepsea sediments [e.g. 1,2] and dissolved pre-historic limestones and salts [e.g. 3,4]), or an approach that limits contamination by terrestrial dust (e.g. collecting from ice, snow and well water in polar regions - locations where the terrestrial dust flux is so low that micrometeorites repre-sent the major dust component [e.g. 5-7]). We have recently set up a micrometeorite collection station on Kwajalein Island in the Republic of the Marshall Is-lands in the Pacific Ocean, using high volume air samplers to collect particles directly from the atmosphere. Collecting at this location exploits the considerably reduced anthropogenic background; Kwajalein is >1000 miles from the nearest continent and for much of the year, trade winds blow from the northeast at 15 to 20 knots providing a continuous stream of oceanic aerosol for sampling. By collecting directly from the atmosphere, the terrestrial age of the particles, and hence weathering they experience, is minimal. We therefore anticipate that the Kwajalein col-lection may include particles that are highly susceptible to weathering and either not preserved well or not found at all in other collections. In addition, this collection method allows for particle arrival times to be constrained so that collections can be timed to correlate with celestial events (e.g. meteor showers). Here we describe the collections and their preparation and report on the initial results.

  7. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    Science.gov (United States)

    Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

    2011-01-01

    Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

  8. Cometary micrometeorites and input of prebiotic compounds

    Directory of Open Access Journals (Sweden)

    Engrand C.

    2014-02-01

    Full Text Available The apparition of life on the early Earth was probably favored by inputs of extraterrestrial matter brought by carbonaceous chondrite-like objects or cometary material. Interplanetary dust collected nowadays on Earth is related to carbonaceous chondrites and to cometary material. They contain in particular at least a few percent of organic matter, organic compounds (amino-acids, PAHs,…, hydrous silicates, and could have largely contributed to the budget of prebiotic matter on Earth, about 4 Ga ago. A new population of cometary dust was recently discovered in the Concordia Antarctic micrometeorite collection. These “Ultracarbonaceous Antarctic Micrometeorites” (UCAMMs are dominated by deuterium-rich and nitrogen-rich organic matter. They seem related to the “CHON” grains identified in the comet Halley in 1986. Although rare in the micrometeorites flux (<5% of the micrometeorites, UCAMMs could have significantly contributed to the input of prebiotic matter. Their content in soluble organic matter is currently under study.

  9. Archway for Radiation and Micrometeorite Occurrence Resistance

    Science.gov (United States)

    Giersch, Louis R.

    2012-01-01

    The environmental conditions of the Moon require mitigation if a long-term human presence is to be achieved for extended periods of time. Radiation, micrometeoroid impacts, high-velocity debris, and thermal cycling represent threats to crew, equipment, and facilities. For decades, local regolith has been suggested as a candidate material to use in the construction of protective barriers. A thickness of roughly 3m is sufficient protection from both direct and secondary radiation from cosmic rays and solar protons; this thickness is sufficient to reduce radiation exposure even during solar flares. NASA has previously identified a need for innovations that will support lunar habitats using lightweight structures because the reduction of structural mass translates directly into additional up and down mass capability that would facilitate additional logistics capacity and increased science return for all mission phases. The development of non-pressurized primary structures that have synergy with the development of pressurized structures is also of interest. The use of indigenous or in situ materials is also a well-known and active area of research that could drastically improve the practicality of human exploration beyond low-Earth orbit. The Archway for Radiation and Micrometeorite Occurrence Resistance (ARMOR) concept is a new, multifunctional structure that acts as radiation shielding and micrometeorite impact shielding for long-duration lunar surface protection of humans and equipment. ARMOR uses a combination of native regolith and a deployed membrane jacket to yield a multifunctional structure. ARMOR is a robust and modular system that can be autonomously assembled on-site prior to the first human surface arrival. The system provides protection by holding a sufficiently thick (3 m) archshaped shell of local regolith around a central cavity. The regolith is held in shape by an arch-shaped jacket made of strong but deployable material. No regolith processing is

  10. The weathering of micrometeorites from the Transantarctic Mountains

    Science.gov (United States)

    van Ginneken, Matthias; Genge, Matthew J.; Folco, Luigi; Harvey, Ralph P.

    2016-04-01

    Micrometeorites are cosmic dust particles recovered from the Earth's surface that dominate the influx of extraterrestrial material accreting to our planet. This paper provides the first in-depth study of the weathering of micrometeorites within the Antarctic environment that will allow primary and secondary features to be distinguished. It is based on the analysis of 366 particles from Larkman Nunatak and 25 from the Transantarctic Mountain collection. Several important morphological categories of weathering effects were identified: (1) irregular and faceted cavities, (2) surface etch pits, (3) infilled cavities, (4) replaced silicate phases, and (5) hydrated and replaced metal. These features indicate that congruent dissolution of silicate phases, in particular olivine, is important in generating new pore space within particles. Comparison of the preservation of glass and olivine also indicates preferential dissolution of olivine by acidic solutions during low temperature aqueous alteration. Precipitation of new hydrous phases within cavities, in particular ferrihydrite and jarosite, results in pseudomorph textures within heavily altered particles. Glass, in contrast, is altered to palagonite gels and shows a sequential replacement indicative of varying water to rock ratios. Metal is variably replaced by Fe-oxyhydroxides and results in decreases in Ni/Fe ratio. In contrast, sulphides within metal are largely preserved. Magnetite, an essential component of micrometeorites formed during atmospheric entry, is least altered by interaction with the terrestrial environment. The extent of weathering in the studied micrometeorites is sensitive to differences in their primary mineralogy and varies significantly with particle type. Despite these differences, we propose a weathering scale for micrometeorites based on both their degree of terrestrial alteration and the level of encrustation by secondary phases. The compositions and textures of weathering products, however

  11. Micrometeorite Impacts in Beringian Mammoth Tusks and a Bison Skull

    Energy Technology Data Exchange (ETDEWEB)

    Hagstrum, Jonathon T.; Firestone, Richard B; West, Allen; Stefanka, Zsolt; Revay, Zsolt

    2010-02-03

    We have discovered what appear to be micrometeorites imbedded in seven late Pleistocene Alaskan mammoth tusks and a Siberian bison skull. The micrometeorites apparently shattered on impact leaving 2 to 5 mm hemispherical debris patterns surrounded by carbonized rings. Multiple impacts are observed on only one side of the tusks and skull consistent with the micrometeorites having come from a single direction. The impact sites are strongly magnetic indicating significant iron content. We analyzed several imbedded micrometeorite fragments from both tusks and skull with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence (XRF). These analyses confirm the high iron content and indicate compositions highly enriched in nickel and depleted in titanium, unlike any natural terrestrial sources. In addition, electron microprobe (EMP) analyses of a Fe-Ni sulfide grain (tusk 2) show it contains between 3 and 20 weight percent Ni. Prompt gamma-ray activation analysis (PGAA) of a particle extracted from the bison skull indicates ~;;0.4 mg of iron, in agreement with a micrometeorite ~;;1 mm in diameter. In addition, scanning electron microscope (SEM) images and XRF analyses of the skull show possible entry channels containing Fe-rich material. The majority of tusks (5/7) have a calibrated weighted mean 14C age of 32.9 +- 1.8 ka BP, which coincides with the onset of significant declines<36 ka ago in Beringian bison, horse, brown bear, and mammoth populations, as well as in mammoth genetic diversity. It appears likely that the impacts and population declines are related events, although their precise nature remains to be determined.

  12. Analysis of Cosmic Spherule Candidates from the Kwajalein Micrometeorite Collection

    Science.gov (United States)

    Wozniakiewicz, P. J.; Price, M. C.; Bradley, J. P.; Ishii, H. A.; Russell, S. S.; Zolensky, M. E.; Brownlee, D. E.

    2015-01-01

    The Kwajalein micrometeorite collection utilised high volume air samplers fitted with 5 micrometer laser-etched polycarbonate membrane filters to capture particles directly from the atmosphere. The filters were changed weekly over several months throughout 2011/12, providing the opportunity to investigate the contemporary flux of micrometeorites. We recently reported the results of our initial survey of cosmic spherule-like particles on several of these filters. We identified three main groups of particle based on bulk compositions: 1. Silicate spherules rich in Mg, Ca and Fe, 2. Silicate spherules rich in Al, Ca, K and/or Na and 3. Fe-rich spherules. Abundances appeared to change over time suggesting links with celestial activity (e.g. meteor showers), however, spherules similar to groups 2 and 3 can be produced by terrestrial and anthropogenic activity (e.g. volcanic microspherules exhibit similar compositions to group 2 spherules and metallic spherules similar to those of group 3 can be formed during fuel combustion). We are now studying the internal structures and chemistries of these spherules and comparing against cosmic spherules identified in other collections to confrim their origins and further contrain the contemporary micrometeorite flux. Particles are being picked, embedded in resin and polished through to reveal their interiors. Here we will describe our ongoing analyses of these particles via SEM. We will also introduce our new collection using this method that is currently being performed in the Antarctic.

  13. 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

  14. Solar wind and micrometeorite effects in the lunar regolith

    Science.gov (United States)

    Housley, R. M.

    1977-01-01

    Using available data from the literature, an outline is formulated for the major physical and chemical effects expected during solar-wind bombardment of the lunar regolith. In agreement with results of Auger and other analyses of the composition of lunar grain surfaces, this outline predicts that solar-wind sputtering will tend to clean exposed grain surfaces by ejecting material at velocities exceeding lunar escape velocity. Results are also discussed which show that Fe is partially reduced in the outer few 10 nm of grain surfaces and that this reduced Fe forms 10-nm-diameter metal spheres throughout the glass during agglutinate formation by micrometeorite impacts. These metal spheres give the agglutinates their distinctive optical and magnetic properties and are partially responsible for the decreasing albedo of the lunar surface with exposure age.

  15. Evaluating changes in the elemental composition of micrometeorites during entry into the earth`s atmosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Dey, S.; Plane, J.M.C.; Feng, W.; Taylor, S.

    of ablation is important for estimating the micrometeorite precursor sizes and flux. Acknowledgements This work is supported by the CSIR XII Plan funded Project GEOSINKS and the PLANEX project, Physical Research Laboratory, Ahmedabad (NGR and MSP...

  16. A unique corundum and refractory metal-nugget bearing micrometeorite P117

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; Reshma, K.; ShyamPrasad, M.

    particle cannot be disregarded. ACKNOWLEDGMENTS The authors (NGR and MSP) are grateful to CSIR for the XII Plan funded Project GEOSINKS and Physical Research Laboratory, Ahmedabad, for PLANEX project on micrometeorites. We are grateful to George Flynn...

  17. The 1994 EUROMET collection of micrometeorites at Cap-Prudhomme, Antarctica

    Science.gov (United States)

    Maurette, M.; Immel, G.; Engrand, C.; Kurat, G.; Pillinger, C. T.

    1994-07-01

    Advance funding from IFRTP (Institut Francais pour la Recherche et pour la Technique Polaire) for micrometeorite collection at Cap-Prudhomme has allowed construction of a new micrometeorite 'factory,' conceived to greatly reduce contamination of the ultraclean ice by our activities. The potential problems include fly ash, rust grains, fuel spills 'sticking to the shoes,' and trace elements from the plasticizers used in plastic tubing. In the new factory, intended to produce and then cycle 10-15 tons of melt ice water per day, all parts exposed to water were replaced by either stainless steel or teflon. After examination with a microscope and their transfer into teflon and or glass vials, all samples were frozen the day of their collection. The factory operated from December 15, 1993, through February 6, 1994. Problems included injuries as well as very bad weather conditions, characterized by both the heaviest snow falls observed and unexpected gusts from a blizzard. Also, several new components of the factory did not function properly under the extreme conditions of Antarctica. Our major objective was to obtain the 'cleanest' and 'purest' 25-50 microns micrometeorites ever collected in Antarctica, for comparison with stratospheric Interplanetary Dust Particles (IDPs). We could not fulfill this premise, but we recovered the best 100-400-micron-size fraction of 'giant' micrometeorites ever collected on Earth. Our 26 daily collections are listed,refering to an 'index of quality.' Aliquots of these daily collections will be distributed to major institutions in Austria, England, the U.S.A., and Japan, to be preserved for future generations. The Antarctica ice sheet is truly a gigantic, ultraclean, and inexhaustible micrometeorite collector, but it is very tricky to recover 'ultraclean' micrometeorites from it.

  18. The contribution to Mercury’s exosphere by sputtering, micrometeorite impact and photon-stimulated desorption

    Science.gov (United States)

    Wurz, P.; Whitby, J.; Martin-Fernandez, J.; Rohner, U.; Lammer, H.; Kolb, C.

    2009-12-01

    We have extended our Monte-Carlo model of exospheres [Wurz and Lammer, Icarus 164, 2003, 1-13] by treating the ion-induced sputtering process, photon-stimulated desorption, and micro-meteorite impact vaporisation in a self-consistent way. Based on available literature data we established a global model for the surface mineralogy of Mercury and from that derived the average elemental composition of the surface. Our total calculated exospheric density at the hermean surface of about 4e7 m^-3 as a result of solar wind sputtering is much less than the experimental total exospheric density of about 1e12 m^-3. The total calculated exospheric density from micro-meteorite impact vaporisation is about 1.58e8 m^-3. We conclude that sputtering and micro-meteorite impact vaporisation contribute only a small fraction of Mercury’s exosphere, at least close to the surface. Because of the considerably larger scale height of atoms released via sputtering into the exosphere, sputtered atoms start to dominate the exosphere at altitudes exceeding around 1000 km, with the exception of some light and abundant species released thermally, e.g. H2 and He. Because of Mercury’s strong gravitational field not all particles released by sputtering and micro-meteorite impact escape. Over extended time scales this will lead to an alteration of the surface composition.

  19. Relict olivines in micrometeorites: Precursors and interactions in the earth`s atmosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Dey, S.; Fernandes, D.; Plane, J.M.C.; Feng, W.; Taylor, S.; Carrillo-Sanchez, J.D.

    by micrometeorites. The CABMOD simulations indicate that particles smaller than 300 µm with entry velocities less than 16 km/s and large ZA (70−90o) o are likely to preserve the relict minerals. Acknowledgements This work is supported by the CSIR XII Plan funded...

  20. Relict Olivines in Micrometeorites: Precursors and Interactions in the Earth’s Atmosphere

    Science.gov (United States)

    Rudraswami, N. G.; Shyam Prasad, M.; Dey, S.; Fernandes, D.; Plane, J. M. C.; Feng, W.; Taylor, S.; Carrillo-Sánchez, J. D.

    2016-11-01

    Antarctica micrometeorites (˜1200) and cosmic spherules (˜5000) from deep sea sediments are studied using electron microscopy to identify Mg-rich olivine grains in order to determine the nature of the particle precursors. Mg-rich olivine (FeO grains enclosed in 162 micrometeorites of different types—unmelted, scoriaceous, and porphyritic—in this study. Forsterites in micrometeorites of different types are crystallized during their formation in solar nebula; their closest analogues are chondrule components of CV-type chondrites or volatile rich CM chondrites. The forsteritic olivines are suggested to have originated from a cluster of closely related carbonaceous asteroids that have Mg-rich olivines in the narrow range of CaO (0.1-0.3wt%), Al2O3 (0.0-0.3wt%), MnO (0.0-0.3wt%), and Cr2O3 (0.1-0.7wt%). Numerical simulations carried out with the Chemical Ablation Model (CABMOD) enable us to define the physical conditions of atmospheric entry that preserve the original compositions of the Mg-rich olivines in these particles. The chemical compositions of relict olivines affirm the role of heating at peak temperatures and the cooling rates of the micrometeorites. This modeling approach provides a foundation for understanding the ablation of the particles and the circumstances in which the relict grains tend to survive.

  1. Delivery of micrometeoritic greenhouse gases and "smoke" particles during the post-lunar "late heavy bombardment" of the Earth

    Science.gov (United States)

    Maurette, M.; Brack, A.; Duprat, J.; Engrand, C.

    (1) Processed micrometeorites in Astrobiology. In previous studies, we considered the contribution of unmelted micrometeorites in astrobiology. We now argue that even processed micrometeorites that are destroyed upon atmospheric entry could have participated in the birth of life on Earth. Unweathered micrometeorites from our new "Concordia-collection" show high sulfur contents of about 5%. With the simple assumption that all sulfur from volatilized micrometeorites is initially oxidized during atmospheric entry, like organic carbon, our model predicts an enormous initial input rate of SO2 in the thermosphere (˜ 1016 g/yr) that lasted for, at least, 100 Myr after the Moon forming impact (this impact blew off the primitive atmosphere). This post-lunar SO2 input was probably quickly transformed into stratospheric sulfate aerosols that were finally deposited in the early oceans. A plausible reaction pathway to eliminate such an excess of sulfates requires the likely existence of abundant early hydrothermal sources, converting sulfates dissolved in water into huge deposits of iron sulfides and exhalations of H2S, as in contemporary sources. In the "sulfide world" promoted by Wächtershäuser, sulfides, FeS and H2S, can reduce CO2 to organic sulfides in the form of thiols, as demonstrated in laboratory simulation experiments. Thiols can lead to thioesters, which probably behaved as activating agents in prebiotic chemistry, according to de Duve; (2) Post-lunar greenhouse effects. It is likely that the greenhouse gases CO2 and H2O released from the Earth's interior counterbalanced the "faint" early Sun luminosity. But these gases were blown off by the Moon forming impact. However, during the first ˜ 100 Myr of the post-lunar period, we predict enormous input rates of three powerful micrometeoritic greenhouse gases (SO2, H2O, CO2). They should have produced a marked heating of the Earth's surface, which had to be counterbalanced by a strong cooling. Hunten and

  2. Ancient micrometeorites suggestive of an oxygen-rich Archaean upper atmosphere

    Science.gov (United States)

    Tomkins, Andrew G.; Bowlt, Lara; Genge, Matthew; Wilson, Siobhan A.; Brand, Helen E. A.; Wykes, Jeremy L.

    2016-05-01

    It is widely accepted that Earth’s early atmosphere contained less than 0.001 per cent of the present-day atmospheric oxygen (O2) level, until the Great Oxidation Event resulted in a major rise in O2 concentration about 2.4 billion years ago. There are multiple lines of evidence for low O2 concentrations on early Earth, but all previous observations relate to the composition of the lower atmosphere in the Archaean era; to date no method has been developed to sample the Archaean upper atmosphere. We have extracted fossil micrometeorites from limestone sedimentary rock that had accumulated slowly 2.7 billion years ago before being preserved in Australia’s Pilbara region. We propose that these micrometeorites formed when sand-sized particles entered Earth’s atmosphere and melted at altitudes of about 75 to 90 kilometres (given an atmospheric density similar to that of today). Here we show that the FeNi metal in the resulting cosmic spherules was oxidized while molten, and quench-crystallized to form spheres of interlocking dendritic crystals primarily of magnetite (Fe3O4), with wüstite (FeO)+metal preserved in a few particles. Our model of atmospheric micrometeorite oxidation suggests that Archaean upper-atmosphere oxygen concentrations may have been close to those of the present-day Earth, and that the ratio of oxygen to carbon monoxide was sufficiently high to prevent noticeable inhibition of oxidation by carbon monoxide. The anomalous sulfur isotope (Δ33S) signature of pyrite (FeS2) in seafloor sediments from this period, which requires an anoxic surface environment, implies that there may have been minimal mixing between the upper and lower atmosphere during the Archaean.

  3. Micrometer- and nanometer-sized platinum group nuggets in micrometeorites from deep-sea sediments of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; Parashar, K.; ShyamPrasad, M.

    I-type micrometeorites. However, the mu m-sized nuggets are seen in fewer specimens (approx. 2.5% of the observed I-type spherules). In all, we analyzed four nuggets of lm size and 213 nanometer-sized nuggets from 13 I-type spherules for platinum...

  4. Expanding earth

    Energy Technology Data Exchange (ETDEWEB)

    Carey, S.W.

    1976-01-01

    Arguments in favor of an expanding earth are presented. The author believes that the theory of plate tectonics is a classic error in the history of geology. The case for the expanding earth is organized in the following way: introductory review - face of the earth, development of expanding earth concept, necessity for expansion, the subduction myth, and definitions; some principles - scale of tectonic phenomena, non-uniformitarianism, tectonic profile, paleomagnetism, asymmetry of the earth, rotation of the earth, and modes of crustal extension; regional studies - western North America, Central America, South-East Asia, and the rift oceans; tests and cause of expansion. 824 references, 197 figures, 11 tables. (RWR)

  5. Why Hexagonal Basalt Columns?

    Science.gov (United States)

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-09

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition.

  6. Expanding subjectivities

    DEFF Research Database (Denmark)

    Lundgaard Andersen, Linda; Soldz, Stephen

    2012-01-01

    A major theme in recent psychoanalytic thinking concerns the use of therapist subjectivity, especially “countertransference,” in understanding patients. This thinking converges with and expands developments in qualitative research regarding the use of researcher subjectivity as a tool to understa......-Saxon and continental traditions, this special issue provides examples of the use of researcher subjectivity, informed by psychoanalytic thinking, in expanding research understanding....

  7. Self-consistent modelling of Mercury’s exosphere by sputtering, micro-meteorite impact and photon-stimulated desorption

    Science.gov (United States)

    Wurz, P.; Whitby, J. A.; Rohner, U.; Martín-Fernández, J. A.; Lammer, H.; Kolb, C.

    2010-10-01

    A Monte-Carlo model of exospheres ( Wurz and Lammer, 2003) was extended by treating the ion-induced sputtering process, photon-stimulated desorption, and micro-meteorite impact vaporisation quantitatively in a self-consistent way starting with the actual release of particles from the mineral surface of Mercury. Based on available literature data we established a global model for the surface mineralogy of Mercury and from that derived the average elemental composition of the surface. This model serves as a tool to estimate densities of species in the exosphere depending on the release mechanism and the associated physical parameters quantitatively describing the particle release from the surface. Our calculation shows that the total contribution to the exospheric density at the Hermean surface by solar wind sputtering is about 4×10 7 m -3, which is much less than the experimental upper limit of the exospheric density of 10 12 m -3. The total calculated exospheric density from micro-meteorite impact vaporisation is about 1.6×10 8 m -3, also much less than the observed value. We conclude that solar wind sputtering and micro-meteorite impact vaporisation contribute only a small fraction of Mercury's exosphere, at least close to the surface. Because of the considerably larger scale height of atoms released via sputtering into the exosphere, sputtered atoms start to dominate the exosphere at altitudes exceeding around 1000 km, with the exception of some light and abundant species released thermally, e.g. H 2 and He. Because of Mercury's strong gravitational field not all particles released by sputtering and micro-meteorite impact escape. Over extended time scales this will lead to an alteration of the surface composition.

  8. Bubble Growth in Lunar Basalts

    Science.gov (United States)

    Zhang, Y.

    2009-05-01

    Although Moon is usually said to be volatile-"free", lunar basalts are often vesicular with mm-size bubbles. The vesicular nature of the lunar basalts suggests that they contained some initial gas concentration. A recent publication estimated volatile concentrations in lunar basalts (Saal et al. 2008). This report investigates bubble growth on Moon and compares with that on Earth. Under conditions relevant to lunar basalts, bubble growth in a finite melt shell (i.e., growth of multiple regularly-spaced bubbles) is calculated following Proussevitch and Sahagian (1998) and Liu and Zhang (2000). Initial H2O content of 700 ppm (Saal et al. 2008) or lower is used and the effect of other volatiles (such as carbon dioxide, halogens, and sulfur) is ignored. H2O solubility at low pressures (Liu et al. 2005), concentration-dependent diffusivity in basalt (Zhang and Stolper 1991), and lunar basalt viscosity (Murase and McBirney 1970) are used. Because lunar atmospheric pressure is essentially zero, the confining pressure on bubbles is completely supplied by the overlying magma. Due to low H2O content in lunar basaltic melt (700 ppm H2O corresponds to a saturation pressure of 75 kPa), H2O bubbles only grow in the upper 16 m of a basalt flow or lake. A depth of 20 mm corresponds to a confining pressure of 100 Pa. Hence, vesicular lunar rocks come from very shallow depth. Some findings from the modeling are as follows. (a) Due to low confining pressure as well as low viscosity, even though volatile concentration is very low, bubble growth rate is extremely high, much higher than typical bubble growth rates in terrestrial melts. Hence, mm-size bubbles in lunar basalts are not strange. (b) Because the pertinent pressures are so low, bubble pressure due to surface tension plays a main role in lunar bubble growth, contrary to terrestrial cases. (c) Time scale to reach equilibrium bubble size increases as the confining pressure increases. References: (1) Liu Y, Zhang YX (2000) Earth

  9. Interaction among minerals, organics and water in comets: insights from Antarctic micrometeorites

    Science.gov (United States)

    Nagahara, Hiroko; Noguchi, Takaaki; Yabuta, Hikaru; Itoh, Shoichi; Sakamoto, Naoya; Mitsunari, Takuya; Okubo, Aya; Okazaki, Ryuji; Nakamura, Tomoki; Tachibana, Shogo; Terada, Kentaro; Ebihara, Mitsuru; Imae, Naoya; Kimura, Makoto

    2016-04-01

    The evolution and interaction of inorganic materials and organic materials are one of the crucial issues of space science, which is also a main topic of current planetary missions. In order to clarify the early stage of evo-lution of primitive materials in the solar system, we have carried out a comprehensive study on micrometeorites collected from the Antarctica virgin snow with SEM, TEM, Carbon-, N-, and O-XANES, and SIMS. On the basis of observation, we estimate the primary materials and the sequence of aqueous reaction in the inorganic and organic materials. The most primitive materials are GEMS (amorphous silicate with Fe-metal and sulfide), small olivine and low-Ca pyroxene, and pyrrhotite, which are embedded in organic materials. The or-ganic materials are macromolecules being rich in C=O groups with subordinate amount of C≡N and/or C=N-C groups, and they accompany D and 15N enrichments. Due to the heavy hydrogen and nitrogen isotopic composi-tions, the organics are estimated to be originated at very low temperature in the molecular cloud or a prestellar environment, which also generated various organic molecules. The aqueous alteration reaction started at first in organic materials, where N-heterocycle, δD, and δ15N are lost and the organics become aromatic-rich. GEMS altered next, where metallic Fe dissolved into water to form Fe-rich saponite remaining Mg-rich amorphous silicate (Stage I). The aromaticity of the organics increases, and the chemical nature of organics becomes close to insoluble organic materials in primitive chondrites. Then, sulfide in GEMS, small olivine and low-Ca pyroxene grains, and Fe-rich saponite react with water to form Mg-rich saponite and Fe-hydroxide (Stage II). Sulfur may have been incorporated into phyllosilicate and/or organics or flew away. Finally, heterogeneous phyllosilicates at Stage II were homogenized to be Mg-rich saponite with formation of carbonate and loss of organics (Stage III). Carbon to form carbonate were

  10. Space science applications for conducting polymer particles: synthetic mimics for cosmic dust and micrometeorites.

    Science.gov (United States)

    Fielding, Lee A; Hillier, Jon K; Burchell, Mark J; Armes, Steven P

    2015-12-11

    Over the last decade or so, a range of polypyrrole-based particles have been designed and evaluated for space science applications. This electrically conductive polymer enables such particles to efficiently acquire surface charge, which in turn allows their acceleration up to the hypervelocity regime (>1 km s(-1)) using a Van de Graaff accelerator. Either organic latex (e.g. polystyrene or poly(methyl methacrylate)) or various inorganic materials (such as silica, olivine or pyrrhotite) can be coated with polypyrrole; these core-shell particles are useful mimics for understanding the hypervelocity impact ionisation behaviour of micro-meteorites (a.k.a. cosmic dust). Impacts on metal targets at relatively low hypervelocities (10 km s(-1)) generate predominately atomic species, since many more chemical bonds are cleaved if the particles impinge with higher kinetic energy. Such fundamental studies are relevant to the calibration of the cosmic dust analyser (CDA) onboard the Cassini spacecraft, which was designed to determine the chemical composition of Saturn's dust rings. Inspired by volcanism observed for one of the Jupiter's moons (Io), polypyrrole-coated sulfur-rich latexes have also been designed to help space scientists understand ionisation spectra originating from sulfur-rich dust particles. Finally, relatively large (20 μm diameter) polypyrrole-coated polystyrene latexes have proven to be useful for understanding the extent of thermal ablation of organic projectiles when fired at ultralow density aerogel targets at up to 6.1 km s(-1) using a Light Gas Gun. In this case, the sacrificial polypyrrole overlayer simply provides a sensitive spectroscopic signature (rather than a conductive overlayer), and the scientific findings have important implications for the detection of organic dust grains during the Stardust space mission.

  11. Strength of Concrete Containing Basalt Fibre

    Directory of Open Access Journals (Sweden)

    Parvez Imraan Ansari

    2015-04-01

    Full Text Available This paper presents the comparative study of effect of basalt fibre on compressive and split tensile strength of M40 grade concrete. The basalt fibre was mixed in concrete by (0.5%, 1%, and 1.5% of its total weight of cement in concrete. Results indicated that the strength increases with increase of basalt fibre content up to 1.0% beyond that there is a reduction in strength on increasing basalt fibre. The results show that the concrete specimen with 1.0% of basalt fibre gives better performance when it compared with 0.5%and 1.5% basalt fibre mix in concrete specimens.

  12. Radiation shielding concrete made of Basalt aggregates.

    Science.gov (United States)

    Alhajali, S; Yousef, S; Kanbour, M; Naoum, B

    2013-04-01

    In spite of the fact that Basalt is a widespread type of rock, there is very little available information on using it as aggregates for concrete radiation shielding. This paper investigates the possibility of using Basalt for the aforementioned purpose. The results have shown that Basalt could be used successfully for preparing radiation shielding concrete, but some attention should be paid to the choice of the suitable types of Basalt and for the neutron activation problem that could arise in the concrete shield.

  13. Strength of Concrete Containing Basalt Fibre

    OpenAIRE

    2015-01-01

    This paper presents the comparative study of effect of basalt fibre on compressive and split tensile strength of M40 grade concrete. The basalt fibre was mixed in concrete by (0.5%, 1%, and 1.5%) of its total weight of cement in concrete. Results indicated that the strength increases with increase of basalt fibre content up to 1.0% beyond that there is a reduction in strength on increasing basalt fibre. The results show that the concrete specimen with 1.0% of basalt fibre gives be...

  14. Investigating the Present Day Cosmic Dust Flux at the Earth's Surface: Initial Results from the Kwajalein Micrometeorite Collection

    Science.gov (United States)

    Wozniakiewicz, P. J.; Bradley, J. P.; Price, M. C.; Zolensky, M. E.; Ishii, H. A.; Brownlee, D. E.; Russell, S. S.

    2014-01-01

    Examination of impact craters on the Long Duration Exposure Facility satellite indicate a present day micrometeoroid flux of approx. 30,000 tonnes [1 after 2]. But what portion of this material arrives at the Earth's surface as micrometeorites? Studies of available micrometeorite collections from deep sea sediments [e.g. 3], Greenland blue ice [e.g. 4] and the South Pole water well [e.g. 1] may be complicated by terrestrial weathering and, in some cases, collection bias (magnetic separation for deep sea sediments) and poorly constrained ages. We have recently set up a micrometeorite collection station on Kwajalein Island in the Republic of the Marshall Islands in the Pacific Ocean, using high volume air samplers to collect particles directly from the atmosphere. By collecting in this way, the terrestrial age of the particles is known, the weathering they experience is minimal, and we are able to constrain particle arrival times. Collecting at this location also exploits the considerably reduced anthropogenic background [5]. Method: High volume air samplers were installed on top of the two-story airport building on Kwajalein. These were fitted with polycarbonate membrane filters with 5µm diameter perforations. The flow rates were set to 0.5m3/min, and filters were changed once a week. After collection, filters were washed to remove salt and concentrate particles [see 5] in preparation for analysis by SEM. Results and Discussion: A selection of filters have been prepared and surveyed. Due to their ease of identification our initial investigations have focused on particles resembling cosmic spherules. The spheres can be divided into three main groups: 1. Silicate spherules rich in Al, Ca, K and Na (to varying degrees), 2. Silicate spherules rich in Mg and Fe and 3. Fe-rich spherules. Group 1 spherules are often vesiculated and can occur as aggregates. They are similar in appearance and composition to volcanic microspheres [e.g. 6] and are thus likely terrestrial in

  15. Irradiation of nitrogen-rich ices by swift heavy ions. Clues for the formation of ultracarbonaceous micrometeorites

    Science.gov (United States)

    Augé, B.; Dartois, E.; Engrand, C.; Duprat, J.; Godard, M.; Delauche, L.; Bardin, N.; Mejía, C.; Martinez, R.; Muniz, G.; Domaracka, A.; Boduch, P.; Rothard, H.

    2016-08-01

    Context. Extraterrestrial materials, such as meteorites and interplanetary dust particles, provide constraints on the formation and evolution of organic matter in the young solar system. Micrometeorites represent the dominant source of extraterrestrial matter at the Earth's surface, some of them originating from large heliocentric distances. Recent analyses of ultracarbonaceous micrometeorites recovered from Antarctica (UCAMMs) reveal an unusually nitrogen-rich organic matter. Such nitrogen-rich carbonaceous material could be formed in a N2-rich environment, at very low temperature, triggered by energetic processes. Aims: Several formation scenarios have been proposed for the formation of the N-rich organic matter observed in UCAMMs. We experimentally evaluate the scenario involving high energy irradiation of icy bodies subsurface orbiting at large heliocentric distances. Methods: The effect of Galactic cosmic ray (GCR) irradiation of ices containing N2 and CH4 was studied in the laboratory. The N2-CH4 (90:10 and 98:2) ice mixtures were irradiated at 14 K by 44 MeV Ni11+ and 160 MeV Ar15+ swift heavy ion beams. The evolution of the samples was monitored using in-situ Fourier transform infrared spectroscopy. The evolution of the initial ice molecules and new species formed were followed as a function of projectile fluence. After irradiation, the target was annealed to room temperature. The solid residue of the whole process left after ice sublimation was characterized in-situ by infrared spectroscopy, and the elemental composition was measured ex-situ. Results: The infrared bands that appear during irradiation allow us to identify molecules and radicals (HCN, CN-, NH3, ...). The infrared spectra of the solid residues measured at room temperature show similarities with that of UCAMMs. The results point towards the efficient production of a poly-HCN-like residue from the irradiation of N2-CH4 rich surfaces of icy bodies. The room temperature residue provides a viable

  16. 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.

  17. The Use of Basalt, Basalt Fibers and Modified Graphite for Nuclear Waste Repository - 12150

    Energy Technology Data Exchange (ETDEWEB)

    Gulik, V.I. [Institute for Nuclear Research, pr. Nauky 47, Kyiv, 03680 (Ukraine); Biland, A.B. [HHK Technologies, 3535 Wilcreast Dr., Houston TX 77042 (United States)

    2012-07-01

    New materials enhancing the isolation of radioactive waste and spent nuclear fuel are continuously being developed.. Our research suggests that basalt-based materials, including basalt roving chopped basalt fiber strands, basalt composite rebar and materials based on modified graphite, could be used for enhancing radioactive waste isolation during the storage and disposal phases and maintaining it during a significant portion of the post-closure phase. The basalt vitrification process of nuclear waste is a viable alternative to glass vitrification. Basalt roving, chopped basalt fiber strands and basalt composite rebars can significantly increase the strength and safety characteristics of nuclear waste and spent nuclear fuel storages. Materials based on MG are optimal waterproofing materials for nuclear waste containers. (authors)

  18. Origin of the Grande Ronde Basalts, Columbia River Basalt Group

    Science.gov (United States)

    Durand, S. R.; Sen, G.; Reidel, S. P.

    2005-12-01

    The Columbia River basalts are generally thought to have formed by plume melting. Takahashi et al. (1998) suggested that the near-aphyric Grande Ronde Basalts (GR), which comprise ~63% of the CRBG, are essentially primary melts formed by nearly complete fusion of eclogite source rock in the plume and that such melting took place ~2.0 GPa. Durand and Sen (2002) examined phenocrysts and whole rock analyses and concluded that all the basalts are non-primary and, more importantly, that they underwent significant "processing" in shallow crustal magma chambers which erased their higher pressure geochemical signal, thus casting doubt on the validity of the eclogitic plume melting model. Here we report the results of our efforts to simulate the higher pressure histories of GR basalts using COMAGMAT and MELTS software. Our intent was to evaluate (1) whether such melts could be derived from primary melts formed by partial melting of a peridotite source as an alternative to the eclogite model, or if bulk melting of eclogite is required; and (2) at what pressure such primary melts could have been in equilibrium with the mantle. We carried out both forward and inverse modeling. In the forward models we chose different starting melt compositions, all produced in laboratory experiments, from peridotite vs. eclogitic sources. Our starting melts were produced by 6-17% partial melting of the peridotite KLB-1 (Hirose and Kushiro, 1993) and 18-40% melting of eclogites (77SL-582; CRB72-31; Keshav et al., 2004; Takahashi et al., 1998) at 1-3.0 GPa. In a second model, our starting melt composition was the most primitive GR lava with 6.5 wt. % MgO. We extrapolated a linear regression through the GR data to 8 wt. % MgO. We then assumed that such a melt was only olivine-equilibrated, and incrementally added olivine while maintaining equilibrium between olivine and melt using a Kd of 0.3, until a melt in equilibrium with the mantle olivine (Fo89) was found. This composition was fractionated

  19. 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

  20. 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...

  1. Technical program plan, Basalt Waste Isolation Project

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-19

    The Basalt Waste Isolation Program covers all activities necessary to assess the feasibility and provide the technology needed to design and construct a nuclear waste repository in basalt. The program is divided into the following areas: program management; systems integration; scientific technology; near-surface test facility; and repository studies. The program is discussed in detail.

  2. The contribution of micrometeorites to the iron stocks of buried podzols, developed in Late-glacial aeolian sand deposits (Brabant, The Netherlands)

    Science.gov (United States)

    van Mourik, Jan; de Vet, Sebastiaan

    2015-04-01

    The surface geology of an extensive part of NW-Europe is dominated by coversands (Late-glacial chemical poor aeolian sand deposits). The geomorphology of coversand landscapes is dominated by ridges and planes. Podzolation is the dominant soil forming process in coversands under moderate humid climatic conditions. Umbric Podzols developed on the ridges under Quercetum-mixtum, Gleyic and Histic Podzols developed in the planes under Alnetum. Even in chemical poor coversands, iron will be released by hydrolysis from iron containing silicate minerals (such as feldspars). It is well known that the vertical iron distribution in Podzols is effected by translocation of active iron from eluvial to illuvial horizons and that iron is leaching to the aquifer. Iron stocks of Podzols, in contrasts, have not been widely studied for comparison purposes of individual soil horizons or between soils. We determined the stocks of active and immobile iron in the horizons of buried xeromorphic Podzols (soils that developed without any contact with groundwater). The results show that the total amount of iron exceeds the potential amount which can be released by hydrolysis from the parent material. Furthermore, to amount of iron that leached to the groundwater is unknown. It is evident that we must find an additional source to explain the total iron stocks in buried Podzols. It is known from analysis of ice cores that the earth atmosphere is subjected to a continuous influx of (iron rich) micrometeorites. The precipitation of micrometeorites (and other aerosols) on the earth surface is concentrated in humid climatic zones with (intensive) rain fall. We analyzed minerals, extracted from the ectorganic horizon of the Initial Podzols, developed in driftsand that stabilized around 1900 AD, overlying Palaeopodzols, buried around 1200 AD. Among blown in quartz grains, we could determine also micrometeorites, embedded in the organic skeleton of the fermentation horizon of the Initial Podzol

  3. Cosmic-ray exposure ages of fossil micrometeorites from mid-Ordovician sediments at Lynna River, Russia

    CERN Document Server

    Meier, Matthias M M; Lindskog, Anders; Maden, Colin; Wieler, Rainer

    2014-01-01

    We measured the He and Ne concentrations of 50 individual extraterrestrial chromite grains recovered from mid-Ordovician (lower Darriwilian) sediments from the Lynna River section near St. Petersburg, Russia. High concentrations of solar wind-like He and Ne found in most grains indicate that they were delivered to Earth as micrometeoritic dust, while their abundance, stratigraphic position and major element composition indicate an origin related to the L chondrite parent body (LCPB) break-up event, 470 Ma ago. Compared to sediment-dispersed extraterrestrial chromite (SEC) grains extracted from coeval sediments at other localities, the grains from Lynna River are both highly concentrated and well preserved. As in previous work, in most grains from Lynna River, high concentrations of solar wind-derived He and Ne impede a clear quantification of cosmic-ray produced He and Ne. However, we have found several SEC grains poor in solar wind Ne, showing a resolvable contribution of cosmogenic 21Ne. This makes it possi...

  4. 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

  5. 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.

  6. Basaltic Soil of Gale Crater: Crystalline Component Compared to Martian Basalts and Meteorites

    Science.gov (United States)

    Treiman, A. H.; Bish, D. L.; Ming, D. W.; Morris, R. V.; Schmidt, M.; Downs, R. T.; Stolper, E. M.; Blake, D. F.; Vaniman, D. T.; Achilles, C. N.; Chipera, S. J.; Bristow, T. F.; Crisp, J. A.; Farmer, J. A.; Morookian, J. M.; Morrison, S. M.; Rampe, E. B.; Sarrazin, P.; Yen, A. S.; Anderosn, R. C.; DesMarais, D. J.; Spanovich, N.

    2013-01-01

    A significant portion of the soil of the Rocknest dune is crystalline and is consistent with derivation from unweathered basalt. Minerals and their compositions are identified by X-ray diffraction (XRD) data from the CheMin instrument on MSL Curiosity. Basalt minerals in the soil include plagioclase, olivine, low- and high-calcium pyroxenes, magnetite, ilmenite, and quartz. The only minerals unlikely to have formed in an unaltered basalt are hematite and anhydrite. The mineral proportions and compositions of the Rocknest soil are nearly identical to those of the Adirondack-class basalts of Gusev Crater, Mars, inferred from their bulk composition as analyzed by the MER Spirit rover.

  7. Mineralogy of Yamato 983885 lunar polymict breccia with a KREEP basalt,a high-Al basalt, a very low-Ti basalt and Mg-rich rocks

    OpenAIRE

    2005-01-01

    Y983885 is a polymict regolith breccia with a KREEP basalt, Mg-rich troctolite/norite, a high-Al basalt, a very low-Ti basalt, a granulite originated from ferroan anorthosite, and Si, Na-rich impact spherules. An igneous KREEP basalt is first reported among lunar meteorites to date. The KREEP basalt is mineralogically distinct from Apollo KREEP basalts due to the lack of the typical Ca zoning from orthopyroxene to pigeonite, instead, the presence of the co-existing pigeonite/augite with chemi...

  8. The eruption characteristics of the Tarim flood basalt

    OpenAIRE

    2012-01-01

    Integration of field investigation, regional stratigraphic comparison, remote sensing and image interpretation allow us to divide the Tarim Permian flood basalt province into three eruptive cycles listed by decreasing age; Kupukuziman flood basalt (KP), Felsic pyroclastic rocks (FP), Kaipaizileike flood basalt (KZ). KP features flood basalt and tuff; in the outcrop in Keping and Yingmaili areas, it can be differentiated into two units containing three thick layers of basaltic lava flows. Thes...

  9. 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.

  10. Isotopic and elemental abundances of copper and zinc in lunar samples, Zagami, Pele’s hairs, and a terrestrial basalt

    Science.gov (United States)

    Herzog, G. F.; Moynier, F.; Albarède, F.; Berezhnoy, A. A.

    2009-10-01

    We used ICP-MS to measure the elemental concentrations and isotopic abundances of Cu and Zn in: nine Ti-rich lunar basalts (10017, 10022, 10024, 10057, 70215, 71055, 74255, 75055, and 75075); size-separated samples prepared by sieving of pyroclastic black glass 74001, orange glass 74022, and the lunar soils 15021, 15231, 70181, and 79221; a basalt from the Piton des Neiges volcano, Reunion Island; two samples of Pele's hairs from the Nyiragongo volcano, Democratic Republic of Congo, and the martian meteorite Zagami. The isotopic fractionation of zinc in lunar basalts and Zagami is mass dependent relative to a terrestrial standard (JMC 400882B). These and published results imply that lunar, terrestrial, meteoritic, and perhaps martian zinc all come from one or more reservoirs linked by mass-dependent fractionation processes. Relative to terrestrial basalts, Ti-rich lunar basalts are enriched in the heavier isotopes of Cu and Zn: we find for Ti-rich lunar basalts the following ranges and averages ±1 - σ (‰): δ 65Cu/ 63Cu ≡ δ 65Cu, 0.1-1.4, 0.5 ± 0.1‰ ( N = 7); δ 66Zn/ 64Zn ≡ δ 66Zn = 0.2-1.9, 1.2 ± 0.2‰ ( N = 8; 10017 excluded). For two terrestrial samples, we find δ 66Zn ˜ +0.3‰ and δ 65Cu ˜ 0‰, which are consistent with published values. The differences between the lunar basalts and terrestrial basalts could reflect minor, planetary-scale vaporization or igneous processes on the Moon. Data for size separates of the pyroclastic glasses 74001 and 74220 confirm the well-known surface correlation of Cu and Zn, but modeling calculations reveal no sharp differences between either the elemental ratios or the isotopic composition of grain interiors and exteriors. The absence of such differences indicates that the isotopic compositions for bulk samples are dominated by a light-isotope-rich surface component. Data for size separates of lunar soils also confirm the surface correlation of Cu and Zn, but an enrichment of heavy rather than light

  11. New Meteorite Type NWA 8159 Augite Basalt: Specimen from a Previously Unsampled Location on Mars?

    Science.gov (United States)

    Agee, C. B.; Muttik, N.; Ziegler, K.; Walton, E. L.; Herd, C. D. K.; McCubbin, F. M.; Santos, A. R.; Simon, J. I.; Peters, T. J.; Tappa, M. J.; Sanborn, M. E.; Yin, Q.-Z.

    2014-01-01

    Up until recently the orthopyroxenite ALH 84001, a singleton martian meteorite type, was the only sample that did not fit within the common SNC types. However with the discovery of the unique basaltic breccia NWA 7034 pairing group [1] the diversity of martian meteorites beyond SNC types was expanded, and now with Northwest Africa (NWA) 8159, and its possible pairing NWA 7635 [2], the diversiy is expanded further with a third unique non-SNC meteorite type. The existence of meteorite types beyond the narrow range seen in SNCs is what might be expected from a random cratering sampling of a geologically long-lived and complex planet such as Mars.

  12. Radionuclide reactions with groundwater and basalts from Columbia River basalt formations

    Energy Technology Data Exchange (ETDEWEB)

    Barney, G.S.

    1981-06-01

    Chemical reactions of radionuclides with geologic materials found in Columbia River basalt formations were studied. The objective was to determine the ability of these formations to retard radionuclide migration from a radioactive waste repository located in deep basalt. Reactions that can influence migration are precipitation, ion-exchange, complexation, and oxidation-reduction. These reactions were studied by measuring the effects of groundwater composition and redox potential (Eh) on radionuclide sorption on fresh basalt surfaces, a naturally altered basalt, and a sample of secondary minerals associated with a Columbia River basalt flow. In addition, radionuclide sorption isotherms were measured for these materials and reaction kinetics were determined. The radionuclides studied were /sup 137/Cs, /sup 85/Sr, /sup 75/Se, /sup 95m/Tc, /sup 237/Np, /sup 241/Am, /sup 226/Ra and /sup 237/Pu. The Freundlich equation accurately describes the isotherms when precipitation of radionuclides does not occur. In general, sorption increased in the order: basalt < altered basalt < secondary minerals. This increase in sorption corresponds to increasing surface area and cation exchange capacity. The Eh of the system had a large effect on technetium, plutonium, and neptunium sorption. Technetium(VII), Pu(VI), and Np(V) are reduced to Tc(IV), Pu(IV), and Np(IV), respectively, under Eh conditions expected in deep basalt formations. The kinetics of radionuclide sorption and basalt-groundwater reactions were observed over a period of 18 weeks. Most sorption reactions stabilized after about four weeks. Groundwater composition changed the least in contact with altered basalt. Contact with secondary minerals greatly increased Ca, K, and Mg concentrations in the groundwater.

  13. What Expands in an Expanding Universe?

    Directory of Open Access Journals (Sweden)

    JOSÉ A. DE FREITAS PACHECO

    2015-12-01

    Full Text Available ABSTRACT In the present investigation, the possible effects of the expansion of the Universe on systems bonded either by gravitational or electromagnetic forces, are reconsidered. It will be shown that the acceleration (positive or negative of the expanding background, is the determinant factor affecting planetary orbits and atomic sizes. In the presently accepted cosmology (ΛCDM all bonded systems are expanding at a decreasing rate that tends to be zero as the universe enters in a de Sitter phase. It is worth mentioning that the estimated expansion rates are rather small and they can be neglected for all practical purposes.

  14. What Expands in an Expanding Universe?

    Science.gov (United States)

    Pacheco, José A De Freitas

    2015-01-01

    In the present investigation, the possible effects of the expansion of the Universe on systems bonded either by gravitational or electromagnetic forces, are reconsidered. It will be shown that the acceleration (positive or negative) of the expanding background, is the determinant factor affecting planetary orbits and atomic sizes. In the presently accepted cosmology (ΛCDM) all bonded systems are expanding at a decreasing rate that tends to be zero as the universe enters in a de Sitter phase. It is worth mentioning that the estimated expansion rates are rather small and they can be neglected for all practical purposes.

  15. Dynamics of a Basaltic Plinian Eruption: Microtextural Studies of Fontana Tephra (Masaya Volcano, Nicaragua)

    Science.gov (United States)

    Costantini, L.; Houghton, B. B.; Bonadonna, C.

    2005-12-01

    Fontana Tephra, one of only 4 well-documented basaltic plinian eruptions, was erupted from Masaya in late Pleistocene. Basaltic explosive volcanism is typically characterized by an open-system magma ascent and degassing that produces lava effusion or weakly explosive eruptions. Fontana Tephra shows instead several plinian pulses involving basaltic-andesite ejecta (SiO2 ~ 53 wt%) and a pre-eruptive volatile content of approximately 2-3 wt%. All juvenile clasts are highly microvesicular and show a low and narrow unimodal density distribution (300-1300 kg/m3) relatively to the other basaltic plinian eruptions (e.g. 600-2400 kg/ m3 density range for the 122 BC Etna and 700-2400 kg/ m3 for the Tarawera 1886 basaltic plinian eruption phase). The density distribution does not change significantly with time during the entire eruption (mean densities between 640 and 840 kg/ m3). However, the groundmass exhibits heterogeneous textures with a variable abundance of microlites both among different samples and especially among clasts within individual samples. This heterogeneity is also reflected upon the vesicle textures, i.e. vesicle number density, size distribution and vesicles shape. Moreover, some clasts have internal gradient of vesicularity which increases from the rim to the center, suggesting that at least part of the clasts continued to expand after fragmentation. Groundmass and vesicle textures are very different from other silicic and basaltic plinian products, showing more similar characteristics to strombolian products, even if the vesicle number densities are prominently higher. We use these textural evidences to hypothesize that at least part of the degassing history of the Fontana Tephra melt was characterized by delayed, late bubble nucleation permitting development of high degrees of volatile supersaturation in a manner analogous to more silicic melts, even if its heterogeneous characters cannot be explained with a classical plinian eruption mechanism.

  16. 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.

  17. Basaltic scorias from Romania - complex building material us for concrete, glazing tiles, ceramic glazes, glass ceramics, mineral wool

    Energy Technology Data Exchange (ETDEWEB)

    Marica, S.; Cetean, V. [PROCEMA S.A., Bucharest (Romania)

    2002-07-01

    The most spectacular deposit of basaltic scoria from Romania is the Heghes Hill from Racos, locality situated in the central part of country. This deposit emerged as grains of various dimensions, as volcanic ash with specific porosity up to 30% and vacuolar basaltic rocks. All types of basaltic scorias have specific vacuolar appearance, red- brick or blackish - grey coloured, scoria textures and similar chemical composition with others basalts of the world. The physical and mechanical characteristics determined included the scorias in the Heghes Hill in the following categories : light rocks (2,98 g/ dmc), porous(11,04%), similar to expanded slag, slightly absorbing rocks (3,86%), with low compression strengths (1700 daN/cmp). Basaltic scoria from Heghes is a very good row material for the manufacture of concrete, for obtain decorative cutting tiles glazing with ceramic and basaltic glazes (up to 40%) varied the range of colours and for obtaining glass ceramic, mineral wool, crushing sand for road maintenance, heat -insulating bricks and shid -proof material. (orig.)

  18. CO2 sequestration in basalts: laboratory measurements

    Science.gov (United States)

    Otheim, L. T.; Adam, L.; van Wijk, K.; McLing, T. L.; Podgorney, R. K.

    2010-12-01

    Geologic sequestration of CO2 is proposed as the only promising large-scale method to help reduce CO2 gas emission by its capture at large point sources and subsequent long-term storage in deep geologic formations. Reliable and cost-effective monitoring will be important aspect of ensuring geological sequestration is a safe, effective, and acceptable method for CO2 emissions mitigation. Once CO2 injection starts, seismic methods can be used to monitor the migration of the carbon dioxide plume. To calibrate changes in rock properties from field observations, we propose to first analyze changes in elastic properties on basalt cores. Carbon dioxide sequestration in basalt rocks results in fluid substitution and mixing of CO2 with water and rock mineralizations. Carbon dioxide sequestration in mafic rocks creates reactions such as Mg2SiO 4 + CaMgSi2O 6 + 4CO2 = Mg 3Ca(CO 3) 4 + 3SiO2 whereby primary silicate minerals within the basalt react with carbonic acid laden water to creating secondary carbonate minerals and silicates. Using time-lapse laboratory scale experiments, such as laser generated ultrasonic wave propagation; it is possible to observe small changes in the physical properties of a rock. We will show velocity and modulus measurements on three basalt core samples for different saturation. The ultimate goal of the project is to track seismic changes due to fluid substitution and mineralization. The porosity of our basalts ranges from 8% to 12%, and the P-wave velocity increases by 20% to 40% from dry to water saturated conditions. Petrographic analysis (CT-scans, thin sections, XRF, XRf) will aid in the characterization of the mineral structure in these basalts and its correlation to seismic properties changes resulting from fluid substitution and mineralization.

  19. Geochemical characterization of oceanic basalts using artificial neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.

    The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a...

  20. Site identification presentation: Basalt Waste Isolation Project

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    The final step in the site identification process for the Basalt Waste Isolation Project is described. The candidate sites are identified. The site identification methodology is presented. The general objectives which must be met in selecting the final site are listed. Considerations used in the screening process are also listed. Summary tables of the guidelines used are included. (DMC)

  1. 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...

  2. Coatings on Atacama Desert Basalt: A Possible Analog for Coatings on Gusev Plains Basalt

    Science.gov (United States)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    Surface coatings on Gusev Plains basalt have been observed and may contain hematite and nanophase Fe-oxides along with enrichments in P, S, Cl, and K relative to the underlying rock. The Gusev coatings may be derived from the dissolution of adhering soil and/or parent rock along with the addition of S and Cl from outside sources. Transient water for dissolution could be sourced from melting snow during periods of high obliquity, acid fog, and/or ground water (Haskin et al., 2005). Coatings on basalt in the hyper-arid (less than 2mm y(sup -1)) Atacama Desert may assist in understanding the chemistry, mineralogy and formation mechanisms of the Gusev basalt coatings. The Atacama Desert climate is proposed to be analogous to a paleo-Mars climate that was characterized by limited aqueous activity when the Gusev coatings could have formed. The objectives of this work are to (i) determine the chemical nature and extent of surface coatings on Atacama Desert basalt, and (ii) assess coating formation mechanisms in the Atacama Desert. Preliminary backscattered electron imaging of Atacama basalt thin-sections indicated that the coatings are as thick as 20 m. The boundary between the coating and the basalt labradorite, ilmenite, and augite grains was abrupt indicating that the basalt minerals underwent no chemical dissolution. The Atacama coatings have been added to the basalt instead of being derived from basalt chemical weathering. Semi-quantitative energy dispersive spectroscopy shows the coatings to be chemically homogeneous. The coating is depleted in Ca (0.9 wt% CaO) and enriched in K (1.3 wt.% K2O) and Si (69.1 wt.% SiO2) relative to the augite and labradorite grains. A dust source enriched in Si (e.g., poorly crystalline silica) and K and depleted in Ca appears to have been added to the basalt surface. Unlike the Gusev coatings, no P, S, and Cl enrichment was observed. However, Fe (3.2 wt.% FeO) was present in the Atacama coatings suggesting the present of Fe

  3. H 2O in basalt and basaltic andesite glass inclusions from four subduction-related volcanoes

    Science.gov (United States)

    Sisson, T. W.; Layne, G. D.

    1993-06-01

    Total dissolved H 2O and major element abundances were measured in basalt and basaltic andesite glass inclusions in olivine phenocrysts from Quaternary eruptions of four subduction-related volcanoes to test the hypothesis that low-MgO high-alumina basalts contain high H 2O at depth [1] and to reveal any petrogenetically significant correlations between arc basalt compositions and H 2O contents. Total dissolved H 2O (combined molecular H 2O and OH groups) measured by ion microprobe in mafic glass inclusions from the 1974 eruption of Fuego, Guatemala, reaches 6.2 wt.%. Dissolved H 2O contents decrease in more evolved Fuego glasses. Correlations of H 2O with MgO, Na 2O, K 2O, S and Cl indicate that aqueous fluid exsolution during magma ascent forced crystallization and differentiation of residual liquids. Low-K 2O magnesian high-alumina basalt glass inclusions from the 3 ka eruption of Black Crater (Medicine Lake volcano, California) have low H 2O contents, near 0.2 wt.%, which are consistent with the MORB-like character of these and other primitive lavas of the Medicine Lake region. Basalt and basaltic andesite glass inclusions from Copco Cone and Goosenest volcano on the Cascade volcanic front north of Mt. Shasta have H 2O contents of up to 3.3 wt.%. The range of H 2O contents in Cascade mafic magmas is too large to have resulted solely from enrichment by crystallization and indicates the participation of an H 2O-rich component in magma generation or crustal-level modification. Whereas fluid-absent melting of amphibole-bearing peridotite can account for the H 2O in most mafic arc liquids, the very high H 2O/alkali ratios of the 1974 Fuego eruptives suggest that an aqueous fluid was involved in the generation of Fuego basalts.

  4. THE MECHANICAL PROPERTIES OF SELF COMPACTING LIGHTWEIGHT MORTAR WITH PUMICE AND EXPANDED PERLITE AGGREGATE

    OpenAIRE

    GONEN, Tahir

    2009-01-01

    Self compacting mortars have been used as repair mortar or to determine component rates of the self compacting concrete. In this study; self compacting lightweight mortars were produced with basaltic pumice and expanded perlite aggregate. Expanded perlite aggregate was used at rates 10, 20, 30, 40 and 50% by volume instead of pumice aggregate and compared with reference specimens made fully pumice aggregate. Self compacting lightweight mortars were compared with self compacting mortar with ri...

  5. Forehead tissue expander.

    Science.gov (United States)

    Kisner, W H

    1991-02-01

    The use of the forehead flap for nasal reconstruction has long been used by reconstructive surgeons. A case is presented in which comprised forehead skin is utilized following expansion by a tissue expander.

  6. Geochemistry of apollo 15 basalt 15555 and soil 15531.

    Science.gov (United States)

    Schnetzler, C C; Philpotts, J A; Nava, D F; Schuhmann, S; Thomas, H H

    1972-01-28

    Major and trace element concentrations have been determined by atomic absorption spectrophotometry, colorimetry, and isotope dilution in Apollo 15 mare basalt 15555 from the Hadley Rille area; trace element concentrations have also been determined in plagioclase and pyroxene separates from basalt 15555 and in soil 15531 from the same area. Basalt 15555 most closely resembles in composition the Apollo 12 olivine-rich basalts. The concentrations of lithium, potassium, rubidium, barium, rare-earth elements, and zirconium in basalt 15555 are the lowest, and the negative europium anomaly is the smallest, reported for lunar basalts; this basalt might be the least differentiated material yet returned from the moon. Crystallization and removal of about 6 percent of plagioclase similar to that contained in the basalt would account for the observed europium anomaly; if plagioclase is not on the liquidus of this basalt, a multistage origin is indicated. Mineral data indicate that plagioclase and pyroxene approached quasi-equilibrium. Most of the chemical differences between basalt 15555 and soil 15531 would be accounted for if the soil were a mixture of 88 percent basalt, 6 percent KREEP (a component, identified in other Apollo soils, rich in potassium, rare-earth elements, and phosphorus) and 6 percent plagioclase (anorthosite?).

  7. Nanoparticulate mineral matter from basalt dust wastes.

    Science.gov (United States)

    Dalmora, Adilson C; Ramos, Claudete G; Querol, Xavier; Kautzmann, Rubens M; Oliveira, Marcos L S; Taffarel, Silvio R; Moreno, Teresa; Silva, Luis F O

    2016-02-01

    Ultra-fine and nano-particles derived from basalt dust wastes (BDW) during "stonemeal" soil fertilizer application have been the subject of some concern recently around the world for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the mining district of Nova Prata in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO2, Al2O3 and Fe2O3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition we have identified a number of trace metals such as Cd, Cu, Cr, Zn that are preferentially concentrated into the finer, inhalable, dust fraction and could so present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical composition in typical BDW samples highlights the need to develop cleaning procedures to minimise exposure to these natural fertilizing basalt dust wastes and is thus of direct relevance to both the industrial sector of basalt mining and to agriculture in the region.

  8. Technical program plan, Basalt Waste Isolation Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-12-01

    The Basalt Waste Isolation Project (BWIP) program as administered by the DOE's Richland Operations Office and Rockwell Hanford Operations is described. The objectives, scope and scientific technologies are discussed. The work breakdown structure of the project includes: project management and support, systems integration, geosciences, hydrology, engineered barriers, test facility design and construction, engineering testing, repository studies, and schedules. The budget of the program including operating and capital cost control is also included. (DC)

  9. On Expanded Cyclic Codes

    CERN Document Server

    Wu, Yingquan

    2008-01-01

    The paper has a threefold purpose. The first purpose is to present an explicit description of expanded cyclic codes defined in $\\GF(q^m)$. The proposed explicit construction of expanded generator matrix and expanded parity check matrix maintains the symbol-wise algebraic structure and thus keeps many important original characteristics. The second purpose of this paper is to identify a class of constant-weight cyclic codes. Specifically, we show that a well-known class of $q$-ary BCH codes excluding the all-zero codeword are constant-weight cyclic codes. Moreover, we show this class of codes achieve the Plotkin bound. The last purpose of the paper is to characterize expanded cyclic codes utilizing the proposed expanded generator matrix and parity check matrix. We analyze the properties of component codewords of a codeword and particularly establish the precise conditions under which a codeword can be represented by a subbasis. With the new insights, we present an improved lower bound on the minimum distance of...

  10. Beringian Megafaunal Extinctions at ~37 ka B.P.: Do Micrometeorites Embedded in Fossil Tusks and Skulls Indicate an Extraterrestial Precursor to the Younger Dryas Event?

    Science.gov (United States)

    Hagstrum, J. T.; Firestone, R. B.; West, A.

    2009-12-01

    Studies of Late Pleistocene megafaunal fossils and their ancient DNA from Beringia (eastern Siberia, Alaska, and the emerged Bering Strait) indicate sharp declines in steppe bison population diversity and horse body size, extinction of the Alaskan wild ass, and local extinctions of brown bear and woolly mammoth genetic lines beginning at about 37 ka B.P. Beringia is also well known for its remarkably preserved Late Pleistocene frozen animal mummies. 14C ages of these mummies are bimodally distributed, having peaks coincident with the earlier ~37 ka B.P., and ~13 ka B.P. Younger Dryas, onset extinction events. Associated with the ~37 ka B.P. event are, for example, the Berezovka mammoth, headless Selerikan horse, steppe bison “Blue Babe”, and baby mammoths “Dima” and “Lyuba”. Analyses of these and other mummies indicate that they died instantly, in mostly healthy condition, with gut contents and high fat reserves indicative of a late summer to autumn season. An assortment of uneaten limbs and other body parts from a variety of species have also been found. Uniformitarian death scenarios inadequately account for the lack of evidence of normal predation and scavenging. Extensive internal injuries (e.g. large bone fractures, hemorrhaging) and apparent rapid burial of the mummies also indicate that something truly unusual happened at the time of these extinction events. We have discovered what appear to be micrometeorites embedded in seven Alaskan mammoth tusks and a Siberian bison skull acquired from commercial sources. 14C ages for five of these fossils have a weighted mean age of 33 ± 2 ka B.P. Laser ablation ICP-MS and XRF analyses of the particles indicate high Fe contents with compositions enriched in Ni and depleted in Ti, similar to Fe meteorites and unlike any natural terrestrial sources. Microprobe analyses of a Fe-Ni sulfide grain from tusk 2 also show that it contains between 3 and 20 weight percent Ni. SEM images and XRF analyses of a bison

  11. Silicon microfabricated beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Othman, A., E-mail: aliman@ppinang.uitm.edu.my; Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A. [Faculty of Electrical Engineering, Universiti Teknologi MARA Malaysia, 40450, Shah Alam, Selangor (Malaysia); Ain, M. F. [School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300,Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-30

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  12. Silicon microfabricated beam expander

    Science.gov (United States)

    Othman, A.; Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A.; Ain, M. F.

    2015-03-01

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  13. Making rhyolite in a basalt crucible

    Science.gov (United States)

    Eichelberger, John

    2016-04-01

    Iceland has long attracted the attention of those concerned with the origin of rhyolitic magmas and indeed of granitic continental crust, because it presents no alternative for such magmas other than deriving them from a basaltic source. Hydrothermally altered basalt has been identified as the progenitor. The fact that rhyolite erupts as pure liquid requires a process of melt-crustal separation that is highly efficient despite the high viscosity of rhyolite melt. Volcanoes in Iceland are foci of basaltic magma injection along the divergent plate boundary. Repeated injection produces remelting, digestion, and sometimes expulsion or lateral withdrawal of material resulting in a caldera, a "crucible" holding down-dropped and interlayered lava flows, tephras, and injected sills. Once melting of this charge begins, a great deal of heat is absorbed in the phase change. Just 1% change in crystallinity per degree gives a melt-present body an effective heat capacity >5 times the subsolidus case. Temperature is thus buffered at the solidus and melt composition at rhyolite. Basalt inputs are episodic ("fires") so likely the resulting generation of rhyolite by melting is too. If frequent enough to offset cooling between events, rhyolite melt extractions will accumulate as a rhyolite magma reservoir rather than as discrete crystallized sills. Evidently, such magma bodies can survive multiple firings without themselves erupting, as the 1875 eruption of Askja Caldera of 0.3 km3 of rhyolite equilibrated at 2-km depth without previous leakage over a ten-millennium period and the surprise discovery of rhyolite magma at 2-km depth in Krafla suggest. Water is required for melting; otherwise melting cannot begin at a temperature lower than that of the heat source. Because the solubility of water in melt is pressure-dependent and almost zero at surface pressure, there must be a minimum depth at which basalt-induced melting can occur and a rhyolite reservoir sustained. In practice, the

  14. Expanding Student Assessment Opportunities.

    Science.gov (United States)

    Bartscher, Beth; Carter, Andrea; Lawlor, Anna; McKelvey, Barbara

    This paper describes an approach for expanding assessment opportunities for students to demonstrate their understanding of content. The targeted population consisted of elementary and junior high school students in two schools in a growing middle-class community in north central Illinois. The elementary school enrolled 467 students and the junior…

  15. Expanding mediation theory

    NARCIS (Netherlands)

    Verbeek, P.P.C.C.

    2012-01-01

    In his article In Between Us, Yoni van den Eede expands existing theories of mediation into the realm of the social and the political, focusing on the notions of opacity and transparency. His approach is rich and promising, but two pitfalls should be avoided. First, his concept of ‘in-between’ runs

  16. 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

  17. Microbial colonization and alteration of basaltic glass

    Directory of Open Access Journals (Sweden)

    J. Einen

    2006-03-01

    Full Text Available Microorganisms have been reported to be associated with the alteration of the glassy margin of seafloor pillow basalts (Thorseth et al., 2001, 2003; Lysnes et al., 2004. The amount of iron and other biological important elements present in basalts and the vast abundance of basaltic glass in the earth's crust, make glass alteration an important process in global element cycling. To gain further insight into microbial communities associated with glass alteration, five microcosm experiments mimicking seafloor conditions were inoculated with seafloor basalt and incubated for one year. Mineral precipitations, microbial attachment to the glass and glass alteration were visualized by scanning electron microscopy (SEM, and the bacterial community composition was fingerprinted by PCR and denaturing gradient gel electrophoresis (DGGE in combination with sequencing. SEM analysis revealed a microbial community with low morphological diversity of mainly biofilm associated and prosthecate microorganisms. Approximately 30 nm thick alteration rims developed on the glass in all microcosms after one year of incubation; this however was also seen in non inoculated controls. Calcium carbonate precipitates showed parallel, columnar and filamentous crystallization habits in the microcosms as well as in the sterile controls. DGGE analysis showed an alteration in bacterial community profiles in the five different microcosms, as a response to the different energy and redox regimes and time. In all microcosms a reduction in number of DGGE bands, in combination with an increase in cell abundance were recorded during the experiment. Sequence analysis showed that the microcosms were dominated by four groups of organisms with phylogenetic affiliation to four taxa: The Rhodospirillaceae, a family containing phototrophic marine organisms, in which some members are capable of heterotrophic growth in darkness and N2 fixation; the family Hyphomicrobiaceae, a group

  18. Microbial colonization and alteration of basaltic glass

    Science.gov (United States)

    Einen, J.; Kruber, C.; Øvreås, L.; Thorseth, I. H.; Torsvik, T.

    2006-03-01

    Microorganisms have been reported to be associated with the alteration of the glassy margin of seafloor pillow basalts (Thorseth et al., 2001, 2003; Lysnes et al., 2004). The amount of iron and other biological important elements present in basalts and the vast abundance of basaltic glass in the earth's crust, make glass alteration an important process in global element cycling. To gain further insight into microbial communities associated with glass alteration, five microcosm experiments mimicking seafloor conditions were inoculated with seafloor basalt and incubated for one year. Mineral precipitations, microbial attachment to the glass and glass alteration were visualized by scanning electron microscopy (SEM), and the bacterial community composition was fingerprinted by PCR and denaturing gradient gel electrophoresis (DGGE) in combination with sequencing. SEM analysis revealed a microbial community with low morphological diversity of mainly biofilm associated and prosthecate microorganisms. Approximately 30 nm thick alteration rims developed on the glass in all microcosms after one year of incubation; this however was also seen in non inoculated controls. Calcium carbonate precipitates showed parallel, columnar and filamentous crystallization habits in the microcosms as well as in the sterile controls. DGGE analysis showed an alteration in bacterial community profiles in the five different microcosms, as a response to the different energy and redox regimes and time. In all microcosms a reduction in number of DGGE bands, in combination with an increase in cell abundance were recorded during the experiment. Sequence analysis showed that the microcosms were dominated by four groups of organisms with phylogenetic affiliation to four taxa: The Rhodospirillaceae, a family containing phototrophic marine organisms, in which some members are capable of heterotrophic growth in darkness and N2 fixation; the family Hyphomicrobiaceae, a group of prosthecate oligotrophic

  19. Quantifying glassy and crystalline basalt partitioning in the oceanic crust

    Science.gov (United States)

    Moore, Rachael; Ménez, Bénédicte

    2016-04-01

    The upper layers of the oceanic crust are predominately basaltic rock, some of which hosts microbial life. Current studies of microbial life within the ocean crust mainly focus on the sedimentary rock fraction, or those organisms found within glassy basalts while the potential habitability of crystalline basalts are poorly explored. Recently, there has been recognition that microbial life develops within fractures and grain boundaries of crystalline basalts, therefore estimations of total biomass within the oceanic crust may be largely under evaluated. A deeper understanding of the bulk composition and fractionation of rocks within the oceanic crust is required before more accurate estimations of biomass can be made. To augment our understanding of glassy and crystalline basalts within the oceanic crust we created two end-member models describing basalt fractionation: a pillow basalt with massive, or sheet, flows crust and a pillow basalt with sheeted dike crust. Using known measurements of massive flow thickness, dike thickness, chilled margin thickness, pillow lava size, and pillow lava glass thickness, we have calculated the percentage of glassy versus crystalline basalts within the oceanic crust for each model. These models aid our understanding of textural fractionation within the oceanic crust, and can be applied with bioenergetics models to better constrain deep biomass estimates.

  20. Mare basalt genesis - Modeling trace elements and isotopic ratios

    Science.gov (United States)

    Binder, A. B.

    1985-11-01

    Various types of mare basalt data have been synthesized, leading to the production of an internally consistent model of the mare basalt source region and mare basalt genesis. The model accounts for the mineralogical, major oxide, compatible siderophile trace element, incompatible trace element, and isotopic characteristics of most of the mare basalt units and of all the pyroclastic glass units for which reliable data are available. Initial tests of the model show that it also reproduces the mineralogy and incompatible trace element characteristics of the complementary highland anorthosite suite of rocks and, in a general way, those of the lunar granite suite of rocks.

  1. Grazing incidence beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  2. East Mariana Basin tholeiites: Cretaceous intraplate basalts or rift basalts related to the Ontong Java plume?

    Science.gov (United States)

    Castillo, P.R.; Pringle, M.S.; Carlson, R.W.

    1994-01-01

    Studies of seafloor magnetic anomaly patterns suggest the presence of Jurassic oceanic crust in a large area in the western Pacific that includes the East Mariana, Nauru and Pigafetta Basins. Sampling of the igneous crust in this area by the Deep Sea Drilling Program (DSDP) and the Ocean Drilling Program (ODP) allows direct evaluation of the age and petrogenesis of this crust. ODP Leg 129 drilled a 51 m sequence of basalt pillows and massive flows in the central East Mariana Basin. 40Ar 39Ar ages determined in this study for two Leg 129 basalts average 114.6 ?? 3.2 Ma. This age is in agreement with the Albian-late Aptian paleontologic age of the overlying sediments, but is distinctively younger than the Jurassic age predicted by magnetic anomaly patterns in the basin. Compositionally, the East Mariana Basin basalts are uniformly low-K tholeiites that are depleted in highly incompatible elements compared to moderately incompatible ones, which is typical of mid-ocean ridge basalts (MORB) erupted near hotspots. The Sr, Nd and Pb isotopic compositions of the tholeiites ( 87Sr 86Srinit = 0.70360-0.70374; 143Nd 144Ndinit = 0.512769-0.512790; 206Pb 204Pbmeas = 18.355-18.386) also overlap with some Indian Ocean Ridge MORB, although they are distinct from the isotopic compositions of Jurassic basalts drilled in the Pigafetta Basin, the oldest Pacific MORB. The isotopic compositions of the East Mariana Basin tholeiites are also similar to those of intraplate basalts, and in particular, to the isotopic signature of basalts from the nearby Ontong Java and Manihiki Plateaus. The East Mariana Basin tholeiites also share many petrologic and isotopic characteristics with the oceanic basement drilled in the Nauru Basin at DSDP Site 462. In addition, the new 110.8 ?? 1.0 Ma 40Ar 39Ar age for two flows from the bottom of Site 462 in the Nauru Basin is indistinguishable from the age of the East Mariana Basin flows. Thus, while magnetic anomaly patterns predict that the igneous

  3. Expanding the HAWC Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Johanna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-17

    The High Altitude Water Cherenkov Gamma-Ray Observatory is expanding its current array of 300 water tanks to include 350 outrigger tanks to increase sensitivity to gamma rays above 10 TeV. This involves creating and testing hardware with which to build the new tanks, including photomultiplier tubes, high voltage supply units, and flash analog to digital converters. My responsibilities this summer included preparing, testing and calibrating that equipment.

  4. 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.

  5. Using 40Ar/39Ar ages of intercalated silicic tuffs to date flood basalts: Precise ages for Steens Basalt Member of the Columbia River Basalt Group

    Science.gov (United States)

    Mahood, Gail A.; Benson, Thomas R.

    2017-02-01

    To establish causality between flood basalt eruptions and extinction events and global environmental effects recorded by isotopic excursions in marine sediments, highly accurate and precise ages for the flood basalts are required. But flood basalts are intrinsically difficult to date. We illustrate how 40Ar/39Ar feldspar ages for silicic tuffs intercalated with and overlying sections of Steens Basalt, the earliest lavas of the Middle Miocene Columbia River Basalt Group in the northwestern United States, provide high-precision ages that, for the first time, make it possible to resolve age differences with stratigraphic position within a section of these flood lavas. The stratigraphically lowest rhyolitic tuff, a fall deposit, yielded an age of 16.592 ± ± 0.028 Ma (FCs = 28.02 Ma), and the uppermost, the alkali rhyolite ignimbrite Tuff of Oregon Canyon, is 16.468 ± ± 0.014 Ma. The argon and stratigraphic data indicate that Steens Basalt eruptions occurred from ∼16.64 to 16.43 Ma in the southern end of its distribution. We estimate that the Steens Mountain geomagnetic reversal occurred at 16.496 ± ± 0.028 Ma (±0.18 Ma total error). Our estimates of the timing for initiation of volcanism and volumetric eruptive rates do not seem to support volcanic forcing by the initial stages of Columbia River Basalt Group eruptions as an explanation for the abrupt warming and carbonate dissolution at the beginning of the Miocene Climatic Optimum.

  6. Preparation of basalt-based glass ceramics

    Directory of Open Access Journals (Sweden)

    MIHOVIL LOGAR

    2003-06-01

    Full Text Available Local and conventional raw materials–massive basalt from the Vrelo locality on Kopaonik mountain–have been used as starting materials to test their suitability for the production of glass-ceramics. Crystallization phenomena of glasses of the fused basalt rocks were studied by X-ray phase analysis, optical microscopy and other techniques. Various heat treatments were used, and their influences, on controlling the microstructures and properties of the products were studied with the aim of developing high strength glass-ceramic materials. Diopside CaMg(SiO32 and hypersthene ((Mg,FeSiO3 were identifies as the crystalline phases. The final products contained considerable amounts of a glassy phase. The crystalline size was in range of 8–480 mm with plate or needle shape. Microhardness, crashing strength and wears resistence of the glass-ceramics ranged from 6.5–7.5, from 2000–6300 kg/cm2 and from 0.1–0.2 g/cm, respectively.

  7. The expanding universe

    CERN Document Server

    Lew, Kristi

    2011-01-01

    People have always been fascinated with the stars above and the universe that contains them. Over the years, astronomers have developed numerous theories to explain how the universe began, how it works, and what its ultimate fate will be. But all of the scientists' questions are far from answered. The Expanding Universe goes beyond the creation of the universe to explain how scientists think the universe works, grows, and changes, including what great thinkers Isaac Newton and Albert Einstein had to say about its fate. Readers will also learn about how researchers are slowly shedding light on

  8. Expanding Your Horizon 2015

    CERN Multimedia

    Kaltenhauser, Kristin

    2015-01-01

    Expanding your horizons is a bi-annual “Science Day” for girls aged 11 to 14, held at the University of Geneva on 14 November. The girls had the opportunity to take part in hands-on workshops held by local professional women in the field of science, mathematics, engineering and technology. For the fourth time, CERN was part of this event, offering three workshops as well as a booth at the Discovery Fair, including Higgnite, an interactive visualization of the Higgs Field.

  9. 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...

  10. 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...

  11. 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.

  12. Het Zevengebergte als supergroeve. Drachenfels, Stenzelberger, Wolkenburger en basalt

    NARCIS (Netherlands)

    Nijland, T.G.

    2015-01-01

    Vanuit Nederlands perspectief kan het Zevengebergte aan de Rijn tegenover Bonn als één grote groeve worden beschouwd. In de middeleeuwen leverde het gebied de bekende Drachenfels trachiet. In de 19e eeuw stichten Nederlanders de Basalt AG in Linz om aan de grote vraag naar basalt voor waterbouwkundi

  13. On Linear Relationships between Trace Elements in Oceanic Basalts

    Institute of Scientific and Technical Information of China (English)

    万渝生

    1991-01-01

    On the basis of the batch melting model*,the author explains the linear relationships between the elements which are often recognized in oceanic basalts,has established mathematic models,discusses some relevant questions,and finally gives an example to show how to apply the method to research on basalts.

  14. 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

  15. Origin of High-Alumina Basalt, Andesite, and Dacite Magmas.

    Science.gov (United States)

    Hamilton, W

    1964-10-30

    The typical volcanic rocks of most island arcs and eugeosynclines, and of some continental environments, are basalt, andesite, and dacite, of high alumina content. The high-alumina basalt differs from tholeiitic basalt primarily in having a greater content of the components of calcic plagioclase. Laboratory data indicate that in the upper mantle, below the level at which the basaltic component of mantle rock is transformed by pressure to eclogite or pyroxenite, the entire basaltic portion probably is melted within a narrow temperature range, but that above the level of that transformation plagioclase is melted selectively before pyroxene over a wide temperature range. The broad spectrum of high-alumina magmas may represent widely varying degrees of partial melting above the transformation level, whereas narrow-spectrum tholeiite magma may represent more complete melting beneath it.

  16. [Determination of Total Iron and Fe2+ in Basalt].

    Science.gov (United States)

    Liu, Jian-xun; Chen, Mei-rong; Jian, Zheng-guo; Wu, Gang; Wu, Zhi-shen

    2015-08-01

    Basalt is the raw material of basalt fiber. The content of FeO and Fe2O3 has a great impact on the properties of basalt fibers. ICP-OES and dichromate method were used to test total Fe and Fe(2+) in basalt. Suitable instrument parameters and analysis lines of Fe were chosen for ICP-OES. The relative standard deviation (RSD) of ICP-OES is 2.2%, and the recovery is in the range of 98%~101%. The method shows simple, rapid and highly accurate for determination of total Fe and Fe(2+) in basalt. The RSD of ICP-OES and dichromate method is 0.42% and 1.4%, respectively.

  17. Study on lithogeochemistry of Middle Jurassic basalts from southern China represented by the Fankeng basalts from Yongding of Fujian Province

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Jincheng; JIANG; Shaoyong; WANG; Xiaolei; YANG; Jinghong; ZHANG; Mengqun

    2006-01-01

    There exists an E-W trending Middle Jurassic volcanic zone in southern China. The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example. The Fankeng basalts have TiO2 contents in the range of 1.92%-3.21%. They are classified as high-Ti basalts. They also have higher total Fe (averaging FeO*= 11.09%). The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cretaceous basalts from southeastern coast of China. They have higher HFSE, such as Th, Nb, Ta, Zr and Ti. Their element ratios related with HFSE, such as Zr/Ba, La/Nb, La/Ta ,Zr/Y, Ti/Y, Ba/Nb, K/Ti and Rb/Zr are similar to those of OIB. The most samples have εNd(T) of -0.70-0.24, which are near chondrite. Some samples have higher εNd(T) of 1.87-3.55.Therefore, these basaltic magmas might be derived from depleted asthenospheric mantle. The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time. The (Early-)Middle Jurassic basalts and gabbros from southeastern Hunan, southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian. Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time. Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.

  18. High water content in primitive continental flood basalts

    Science.gov (United States)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-01-01

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB. PMID:27143196

  19. Mineral chemistry of Pangidi basalt flows from Andhra Pradesh

    Indian Academy of Sciences (India)

    P V Nageswara Rao; P C Swaroop; Syed Karimulla

    2012-04-01

    This paper elucidates the compositional studies on clinopyroxene, plagioclase, titaniferous magnetite and ilmenite of basalts of Pangidi area to understand the geothermometry and oxybarometry conditions. Petrographic evidence and anorthite content (up to 85%) of plagioclase and temperature estimates of clinopyroxene indicate that the clinopyroxene is crystallized later than or together with plagioclase. The higher An content indicates that the parent magma is tholeiitic composition. 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 (748–898°C) in middle and upper basalt flows. From this it can be inferred that the clinopyroxene is crystallized earlier than Fe–Ti oxide phases reequilibration, which indicates that the clinopyroxene temperature is the approximate eruption temperature of the present lava flows. The wide range of temperatures (900–1190°C) attained by clinopyroxene may point out that the equilibration of clinopyroxene crystals initiated from depth till closer to the surface before the melt erupted. 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 oxygen fugacity conditions during cooling of middle and upper basalt flows. The variation of oxygen fugacity indicates the oxidizing conditions for lower basalt flow (9.48–10.3) and extremely reducing conditions for middle (12.1–15.5) and upper basalt (12.4–15.54) flows prevailed at the time of cooling. Temperature vs. (FeO+Fe2O3)/(FeO+Fe2O3+MgO) data plots for present

  20. Pliocene Basaltic Volcanism in The East Anatolia Region (EAR), Turkey

    Science.gov (United States)

    Oyan, Vural; Özdemir, Yavuz; Keskin, Mehmet

    2016-04-01

    East Anatolia Region (EAR) is one of the high Plateau which is occurred with north-south compressional regime formed depending on continent-continent collision between Eurasia and Arabia plates (Şengör and Kidd, 1979). Recent studies have revealed that last oceanic lithosphere in the EAR have completely depleted to 20 million years ago based on fission track ages (Okay et al. 2010). Our initial studies suggest that extensively volcanic activity in the EAR peaked in the Pliocene and continued in the same productivity throughout Quaternary. Voluminous basaltic lava plateaus and basaltic lavas from local eruption centers occurred as a result of high production level of volcanism during the Pliocene time interval. In order to better understand the spatial and temporal variations in Pliocene basaltic volcanism and to reveal isotopic composition, age and petrologic evolution of the basaltic volcanism, we have started to study basaltic volcanism in the East Anatolia within the framework of a TUBITAK project (project number:113Y406). Petrologic and geochemical studies carried out on the Pliocene basaltic lavas indicate the presence of subduction component in the mantle source, changing the character of basaltic volcanism from alkaline to subalkaline and increasing the amount of spinel peridotitic melts (contributions of lithospheric mantle?) in the mantle source between 5.5-3.5 Ma. FC, AFC and EC-AFC modelings reveal that the while basaltic lavas were no or slightly influenced by crustal contamination and fractional crystallization, to more evolved lavas such as bazaltictrachyandesite, basalticandesite, trachybasalt might have been important processes. Results of our melting models and isotopic analysis data (Sr, Nd, Pb, Hf, 18O) indicate that the Pliocene basaltic rocks were derived from both shallow and deep mantle sources with different melting degrees ranging between 0.1 - 4 %. The percentage of spinel seems to have increased in the mantle source of the basaltic

  1. The Artful Universe Expanded

    Energy Technology Data Exchange (ETDEWEB)

    Bassett, B A [Institute of Cosmology and Gravitation, University of Portsmouth (United Kingdom)

    2005-07-29

    The cosmos is an awfully big place and there is no better guide to its vast expanse and fascinating nooks and crannies than John Barrow. A professor of mathematical sciences at Cambridge University, Barrow embodies that rare combination of highly polished writer and expert scientist. His deft touch brings together the disparate threads of human knowledge and weaves them into a tapestry as rich and interesting for the expert as it is for the layperson. The Artful Universe Expanded is an updated edition of this popular book first published in 1995. It explores the deeply profound manner in which natural law and the nature of the cosmos have moulded and shaped us, our cultures and the very form of our arts and music-a new type of 'cosmic' anthropology. The main themes Barrow chooses for revealing this new anthropology are the subjects of evolution, the size of things, the heavens and the nature of music. The book is a large, eclectic repository of knowledge often unavailable to the layperson, hidden in esoteric libraries around the world. It rivals The Da Vinci Code for entertainment value and insights, but this time it is Nature's code that is revealed. It is rare indeed to find common threads drawn through topics as diverse as The Beetles, Bach and Beethoven or between Jackson Pollock, the Aztecs, Kant, Picasso, Byzantine mosaics, uranium-235 and the helix nebula. Barrow unerringly binds them together, presenting them in a stimulating, conversational style that belies the amount of time that must have gone into researching this book. Dip into it at random, or read it from cover to cover, but do read it. The Artful Universe Expanded is an entertaining antidote to the oft-lamented pressures to know more and more about less and less and the apparently inexorable march of specialization. On reading this book one can, for a short time at least, hold in one's mind a vision that unifies science, art and culture and glimpse a universal tapestry of great

  2. Calcium Sulfate in Atacama Desert Basalt: A Possible Analog for Bright Material in Adirondack Basalt, Gusev Crater

    Science.gov (United States)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    The Atacama Desert in northern Chile is one of the driest deserts on Earth (basalt parent material observed white material in the interior vesicles of surface basalt. This is strikingly similar to the bright-white material present in veins and vesicles of the Adirondack basalt rocks at Gusev Crater which are presumed to consist of S, Cl, and/or Br. The abundance of soil gypsum/anhydrite in the area of the Atacama basalt suggested that the white material consisted of calcium sulfate (Ca-SO4) which was later confirmed by SEM/EDS analysis. This work examines the Ca-SO4 of Atacama basalt in an effort to provide insight into the possible nature of the bright material in the Adirondack basalt of Gusev Crater. The objectives of this work are to (i) discuss variations in Ca-SO4 crystal morphology in the vesicles and (ii) examine the Ca-SO4 interaction(s) with the basalt interior.

  3. 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

  4. Acid weathering of basalt and basaltic glass: 2. Effects of microscopic alteration textures on spectral properties

    Science.gov (United States)

    Smith, Rebecca J.; Horgan, Briony H. N.; Mann, Paul; Cloutis, Edward A.; Christensen, Philip R.

    2017-01-01

    Acid alteration has long been proposed for the Martian surface, and so it is important to understand how the resulting alteration textures affect surface spectra. Two basaltic materials of varying crystallinity were altered in two different H2SO4 solutions (pH 1 and pH 3) for 220 days. The unaltered and altered samples were studied in the visible and near infrared (VNIR) and thermal infrared (TIR), and select samples were chosen for scanning electron microscopy analysis. Materials altered in pH 3 solutions showed little to no physical alteration, and their spectral signatures changed very little. In contrast, all materials altered in pH 1 acid displayed silica-rich alteration textures, and the morphology differed based on starting material crystallinity. The more crystalline material displayed extensive alteration reaching into the sample interiors and had weaker silica spectral features. The glass sample developed alteration layers tens of microns thick, exhibiting amorphous silica-rich spectral features that completely obscured the substrate. Thus, the strong absorption coefficient of silica effectively decreases the penetration depth of TIR spectral measurements, causing silica abundances to be grossly overestimated in remote sensing data. Additionally, glass samples with silica layers exhibited distinct concave up blue spectral slopes in the VNIR. Spectra from the northern lowland plains of Mars are modeled with high abundances of amorphous silica and exhibit concave up blue spectral slopes and are thus consistent with acid altered basaltic glass. Therefore, we conclude that large regions of the Martian surface may have formed through the interaction of basaltic glass with strongly acidic fluids.

  5. Alteration of basaltic glasses from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    Textural, mineralogical and compositional characteristics of basaltic glasses from the Central Indian Ocean show them to be altered to varying extents through their interaction with the seawater, resulting in the formation of palagonite. The major...

  6. Mineralogy of Silica Polymorphs in Basaltic Clasts in Eucrites

    Science.gov (United States)

    Ono, H.; Takenouchi, A.; Mikouchi, T.

    2016-08-01

    We analyzed silica polymorphs in basaltic clasts in Y-75011, Pasamonte and Stannern eucrites. Cristobalite and quartz have been found, which suggests wide occurrence of hydrothermal activity throughout the crust of Vesta.

  7. Two new basaltic asteroids in the Outer Main Belt

    CERN Document Server

    Duffard, R

    2007-01-01

    The identification of other basaltic objects in the asteroid belt is mandatory to explain the diversity in the collection of basaltic meteorites. This diversity requires more than one differentiated parent body, a fact that is consistent with the diversity of differentiated parent bodies implied by the iron meteorites. Based on a list of previously identified candidate basaltic (V-type) asteroids, two asteroids in the outer main belt, (7472) Kumakiri and (10537) 1991 RY16, were spectroscopically observed during an observational run in Calar Alto Observatory, Spain. We confirm the V-type character of these two asteroids that, together with (1459) Magnya, become the only known traces of basaltic found in the outer main belt up to now. We also demonstrate that the searching for candidate V-type asteroids using a photometric survey, like the Sloan Digital Sky Survey, produces reliable results.

  8. The Artful Universe Expanded

    Science.gov (United States)

    Barrow, John D.

    2005-07-01

    Our love of art, writes John Barrow, is the end product of millions of years of evolution. How we react to a beautiful painting or symphony draws upon instincts laid down long before humans existed. Now, in this enhanced edition of the highly popular The Artful Universe , Barrow further explores the close ties between our aesthetic appreciation and the basic nature of the Universe. Barrow argues that the laws of the Universe have imprinted themselves upon our thoughts and actions in subtle and unexpected ways. Why do we like certain types of art or music? What games and puzzles do we find challenging? Why do so many myths and legends have common elements? In this eclectic and entertaining survey, Barrow answers these questions and more as he explains how the landscape of the Universe has influenced the development of philosophy and mythology, and how millions of years of evolutionary history have fashioned our attraction to certain patterns of sound and color. Barrow casts the story of human creativity and thought in a fascinating light, considering such diverse topics as our instinct for language, the origins and uses of color in nature, why we divide time into intervals as we do, the sources of our appreciation of landscape painting, and whether computer-generated fractal art is really art. Drawing on a wide variety of examples, from the theological questions raised by St. Augustine and C.S. Lewis to the relationship between the pure math of Pythagoras and the music of the Beatles, The Artful Universe Expanded covers new ground and enters a wide-ranging debate about the meaning and significance of the links between art and science.

  9. 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

  10. Radiolytic Hydrogen Production in the Subseafloor Basaltic Aquifer

    Science.gov (United States)

    Dzaugis, Mary E.; Spivack, Arthur J.; Dunlea, Ann G.; Murray, Richard W.; D’Hondt, Steven

    2016-01-01

    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. However, 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 support as many as

  11. Genesis of highland basalt breccias - A view from 66095

    Science.gov (United States)

    Garrison, J. R., Jr.; Taylor, L. A.

    1980-01-01

    Electron microprobe and defocused beam analyses of the lunar highland breccia sample 66095 show it consists of a fine-grained subophitic matrix containing a variety of mineral and lithic clasts, such as intergranular and cataclastic ANT, shocked and unshocked plagioclase, and basalts. Consideration of the chemistries of both matrix and clasts provides a basis for a qualitative three-component mixing model consisting of an ANT plutonic complex, a Fra Mauro basalt, and minor meteoric material.

  12. Radiolytic Hydrogen Production in the Subseafloor Basaltic Aquifer.

    Science.gov (United States)

    Dzaugis, Mary E; Spivack, Arthur J; Dunlea, Ann G; Murray, Richard W; D'Hondt, Steven

    2016-01-01

    Hydrogen (H2) is produced in geological settings by dissociation of water due to radiation from radioactive decay of naturally occurring uranium ((238)U, (235)U), thorium ((232)Th) and potassium ((40)K). 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. However, 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 support as

  13. Basalt: Biologic Analog Science Associated with Lava Terrains

    Science.gov (United States)

    Lim, D. S. S.; Abercromby, A.; Kobs-Nawotniak, S. E.; Kobayashi, L.; Hughes, S. S.; Chappell, S.; Bramall, N. E.; Deans, M. C.; Heldmann, J. L.; Downs, M.; Cockell, C. S.; Stevens, A. H.; Caldwell, B.; Hoffman, J.; Vadhavk, N.; Marquez, J.; Miller, M.; Squyres, S. W.; Lees, D. S.; Fong, T.; Cohen, T.; Smith, T.; Lee, G.; Frank, J.; Colaprete, A.

    2015-12-01

    This presentation will provide an overview of the BASALT (Biologic Analog Science Associated with Lava Terrains) program. BASALT research addresses Science, Science Operations, and Technology. Specifically, BASALT is focused on the investigation of terrestrial volcanic terrains and their habitability as analog environments for early and present-day Mars. Our scientific fieldwork is conducted under simulated Mars mission constraints to evaluate strategically selected concepts of operations (ConOps) and capabilities with respect to their anticipated value for the joint human and robotic exploration of Mars. a) Science: The BASALT science program is focused on understanding habitability conditions of early and present-day Mars in two relevant Mars-analog locations (the Southwest Rift Zone (SWRZ) and the East Rift Zone (ERZ) flows on the Big Island of Hawai'i and the eastern Snake River Plain (ESRP) in Idaho) to characterize and compare the physical and geochemical conditions of life in these environments and to learn how to seek, identify, and characterize life and life-related chemistry in basaltic environments representing these two epochs of martian history. b) Science Operations: The BASALT team will conduct real (non-simulated) biological and geological science at two high-fidelity Mars analogs, all within simulated Mars mission conditions (including communication latencies and bandwidth constraints) that are based on current architectural assumptions for Mars exploration missions. We will identify which human-robotic ConOps and supporting capabilities enable science return and discovery. c) Technology: BASALT will incorporate and evaluate technologies in to our field operations that are directly relevant to conducting the scientific investigations regarding life and life-related chemistry in Mars-analogous terrestrial environments. BASALT technologies include the use of mobile science platforms, extravehicular informatics, display technologies, communication

  14. Mechanical and morphological properties of basalt filled polymer matrix composites

    OpenAIRE

    2009-01-01

    Purpose: The aim of this work is to study the effect of basalt on physical, mechanical and morphological of the injection molded LDPE.Design/methodology/approach: In this study, the effect of basalt was investigated as a filler material in polymer matrix composite (PMC) and low density polyethylene (LDPE) was chosen as a matrix material.Findings: A variety of mechanical tests were performed on the resultant composites which has appropriate compositions. Tensile, flexu...

  15. 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.

  16. Geochemical characterization of oceanic basalts using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Iyer Sridhar D

    2009-12-01

    Full Text Available Abstract The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB under one class i.e., as mid-oceanic ridge basalts (MORB. Hence, a method is specifically needed to identify the OFB as normal (N-MORB, enriched (E-MORB and ocean island basalts (OIB. We have applied Artificial Neural Network (ANN technique as a supervised Learning Vector Quantisation (LVQ to identify the inherent geochemical signatures present in the Central Indian Ocean Basin (CIOB basalts. A range of N-MORB, E-MORB and OIB dataset was used for training and testing of the network. Although the identification of the characters as N-MORB, E-MORB and OIB is completely dependent upon the training data set for the LVQ, but to a significant extent this method is found to be successful in identifying the characters within the CIOB basalts. The study helped to geochemically delineate the CIOB basalts as N-MORB with perceptible imprints of E-MORB and OIB characteristics in the form of moderately enriched rare earth and incompatible elements. Apart from the fact that the magmatic processes are difficult to be deciphered, the architecture performs satisfactorily.

  17. Geochemical characterization of oceanic basalts using Artificial Neural Network.

    Science.gov (United States)

    Das, Pranab; Iyer, Sridhar D

    2009-12-23

    The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). We have applied Artificial Neural Network (ANN) technique as a supervised Learning Vector Quantisation (LVQ) to identify the inherent geochemical signatures present in the Central Indian Ocean Basin (CIOB) basalts. A range of N-MORB, E-MORB and OIB dataset was used for training and testing of the network. Although the identification of the characters as N-MORB, E-MORB and OIB is completely dependent upon the training data set for the LVQ, but to a significant extent this method is found to be successful in identifying the characters within the CIOB basalts. The study helped to geochemically delineate the CIOB basalts as N-MORB with perceptible imprints of E-MORB and OIB characteristics in the form of moderately enriched rare earth and incompatible elements. Apart from the fact that the magmatic processes are difficult to be deciphered, the architecture performs satisfactorily.

  18. Testing the Origins of Basalt Fragments fro Apollo 16

    Science.gov (United States)

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

    2013-01-01

    Several 2-4 mm regolith fragments of basalt from the Apollo 16 site were recently described by [1]. These included a high-Ti vitrophyric basalts (60603,10-16) and one very-low-titanium (VLT) crystalline basalt (65703,9-13). As Apollo 16 was the only highlands sample return mission distant from the maria, identification of basaltic samples at the site indicates input from remote sites via impact processes [1]. However, distinguishing between impact melt and pristine basalt can be notoriously difficult and requires significant sample material [2-6]. The crystal stratigraphy method utilizes essentially non-destructive methods to make these distinctions [7,8]. Crystal stratigraphy combines quantitative petrography in the form of crystal size distributions (CSDs) coupled with mineral geochemistry to reveal the petrogenetic history of samples. The classic CSD plot of crystal size versus population density can reveal insights on growth/cooling rates, residence times, and magma history which in turn can be used to evaluate basaltic vs impact melt origin [7-9]. Electron microprobe (EMP) and laser ablation (LA)-ICP-MS analyses of mineral phases complement textural investigations. Trace element variations document subtle changes occurring during the formation of the samples, and are key in the interpretation and preservation of this rare lunar sample collection.

  19. The Distribution of Basaltic Asteroids in the Main Belt

    CERN Document Server

    Moskovitz, Nicholas A; Gaidos, Eric; Willman, Mark; Nesvorny, David; Fevig, Ronald; Ivezic, Zeljko

    2008-01-01

    We present the observational results of a survey designed to target and detect asteroids whose colors are similar to those of Vesta family members and thus may be considered as candidates for having a basaltic composition. Fifty basaltic candidates were selected with orbital elements that lie outside of the Vesta dynamical family. Optical and near-infrared spectra were used to assign a taxonomic type to 11 of the 50 candidates. Ten of these were spectroscopically confirmed as V-type asteroids, suggesting that most of the candidates are basaltic and can be used to constrain the distribution of basaltic material in the Main Belt. Using our catalog of V-type candidates and the success rate of the survey, we calculate unbiased size-frequency and semi-major axis distributions of V-type asteroids. These distributions, in addition to an estimate for the total mass of basaltic material, suggest that Vesta was the predominant contributor to the basaltic asteroid inventory of the Main Belt, however scattered planetesim...

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

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, G.C.; Grandstaff, D.E. (Temple Univ., Philadelphia, PA (USA). Dept. of Geology)

    1984-11-21

    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.

  1. 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.

  2. Space-Time-Isotopic Trends of Snake River Plain Basalts

    Science.gov (United States)

    Jean, M. M.; Hanan, B. B.; Shervais, J. W.

    2010-12-01

    The Snake River Plain (SRP) volcanic province is an 800 km track of basalt extending from the Owyhee Plateau to its current terminus, the Yellowstone Plateau. It is one of several late-Tertiary magmatic terranes that also include the Cascades magmatic arc, the Columbia River basalts, and the Oregon Plateau basalts; all of which are adjacent to the Basin and Range Province extensional system (Hughes and McCurry, 2002). This province represents the track of the Yellowstone plume and consists of basalt that is compositionally similar to ocean-island basalt. This basalt overlies a series of rhyolitic eruptive centers (overlapping caldera complexes, ignimbrites, and caldera-filling eruptions) that signal the arrival of the plume head (Christiansen, 2001) and herald the onset of plume-related rhyolitic and basaltic volcanism (Pierce et al., 2002). Observed within the SRP are two basalt types: the dominant low-K olivine tholeiites and less common high-K alkaline basalts. We report new Sr-, Nd-, and Pb-isotopic analyses of these two basalt types from all three SRP provinces: eastern, central, and western. Low-K tholeiites are enriched in 143Nd/144Nd and 86Sr/87Sr and forms a quasi-linear array in Pb-isotope space, along with Craters of the Moon and eastern SRP basalts. High-K lavas are found largely in the western plain, and have a uniquely different isotopic signature. They are depleted in 143Nd/144Nd and 86Sr/87Sr, relative to the low-K tholeiites, and plot closer to the BSE component of Zindler and Hart (1986). They also share the same Pb-isotopic space with high-K basalts from Smith Prairie (Boise River Group 2 of Vetter and Shervais, 1992). One low-K tholeiite - Eureka North, plots with these high alkali basalts. Mass balance models have demonstrated an increasing plume component from the Yellowstone caldera in the east to the craton edge in the west. The lavas analyzed in this study conform remarkably to this model. The mass fraction of plume component in western

  3. Elastic laboratory measurements and modeling of saturated basalts

    Science.gov (United States)

    Adam, Ludmila; Otheim, Thomas

    2013-03-01

    Understanding the elastic behavior of basalt is important to seismically monitor volcanoes, subsea basalts, and carbon sequestration in basalt. We estimate the elastic properties of basalt samples from the Snake River Plain, Idaho, at ultrasonic (0.8 MHz) and seismic (2-300 Hz) frequencies. To test the sensitivity of seismic waves to the fluid content in the pore structure, measurements are performed at three saturation conditions: saturated with liquid CO2, water, and dry. When CO2 replaces water, the P-wave velocity drops, on average, by 10%. Vesicles and cracks, observed in the rock microstructure, control the relaxation of pore-fluid pressures in the rock as a wave propagates. The bulk and shear moduli of basalts saturated with liquid CO2 are not frequency dependent, suggesting that fluid pore pressures are in equilibrium between 2 Hz and 0.8 MHz. However, when samples are water saturated, the bulk modulus of the rock is frequency dependent. Modeling with Gassmann's equations predicts the measured saturated rock bulk modulus for all fluids for frequencies below 20 Hz but underpredicts the water-saturated basalt bulk modulus for frequencies greater than 20 Hz. The most likely reason is that the pore-fluid pressures are unrelaxed. Instead, the ultrasonic frequency rock moduli are modeled with high-frequency elastic theories of squirt flow and Kuster-Toksöz (KT). Although KT's model is based on idealized pore shapes, a combination of spheres (vesicles) and penny-shaped cracks (fractures) interpreted and quantified from petrographical data predicts the ultrasonic dry and saturated rock moduli for the measured basalts.

  4. Joint inversion of 3-D seismic, gravimetric and magnetotelluric data for sub-basalt imaging in the Faroe-Shetland Basin

    Science.gov (United States)

    Heincke, B.; Moorkamp, M.; Jegen, M.; Hobbs, R. W.

    2012-12-01

    collected along parallel lines by a shipborne gradiometer and the marine MT data set is composed of 41 stations that are distributed over the whole investigation area. Logging results from a borehole located in the central part of the investigation area enable us to derive parameter relationships between seismic velocities, resistivities and densities that are adequately describe the rock property behaviors of both the basaltic lava flows and sedimentary layers in this region. In addition, a 3-D reflection seismic survey covering the central part allows us to incorporate the top of basalt and other features as constraints in the joint inversions and to evaluate the quality of the final results. Literature: D. Colombo, M. Mantovani, S. Hallinan, M. Virgilio, 2008. Sub-basalt depth imaging using simultaneous joint inversion of seismic and electromagnetic (MT) data: a CRB field study. SEG Expanded Abstract, Las Vegas, USA, 2674-2678. M. Jordan, J. Ebbing, M. Brönner, J. Kamm , Z. Du, P. Eliasson, 2012. Joint Inversion for Improved Sub-salt and Sub-basalt Imaging with Application to the More Margin. EAGE Expanded Abstracts, Copenhagen, DK. M. Moorkamp, B. Heincke, M. Jegen, A.W.Roberts, R.W. Hobbs, 2011. A framework for 3-D joint inversion of MT, gravity and seismic refraction data. Geophysical Journal International, 184, 477-493.

  5. Basalt here, basalt there: Constraining the basaltic nature of eight Vp-type asteroids in the inner and outer main asteroid belt

    Science.gov (United States)

    Hardersen, Paul Scott; Reddy, Vishnu

    2016-10-01

    The distribution and abundance of basaltic material in the main asteroid belt has multiple implications that impact our understanding of the physical and thermal conditions that existed in the inner solar system during the formation epoch about 4.6 Gyr ago. Subjects impacted by a more accurate basaltic asteroid inventory include the efficacy of current inner solar system heating model predictions (Al-26 and T Tauri induction heating), the existence of differentiated parent bodies other than (4) Vesta, the dispersion efficiency of Vestoids by YORP forces, and the predictive ability of the V-taxonomy in predicting a basaltic surface composition. This work reports on a continuation of an effort to better constrain the basaltic asteroid population in the main asteroid belt with the goal of observing about 650 Vp-type asteroids. This work focuses on two populations: a) those Vp-classified asteroids (Carvano et al., 2010) in the spatial vicinity of (4) Vesta (candidate Vestoids) in the inner main belt, and b) Vp-classified asteroids in the outer main belt beyond 2.5 AU. Thus far, 23 Vp-type asteroids and candidate Vestoids have been observed and analyzed, which are all strongly suggestive of a basaltic surface composition (Hardersen et al., 2014, 2015, 2016 (in preparation)). However, unpublished work is beginning to show that the Vp taxonomic class is less accurate in its ability to identify basaltic surface compositions in outer-belt Vp-type asteroids. We report here on an additional set of Vp-type asteroids that were observed at the NASA Infrared Telescope Facility (IRTF) in December 2015 and January 2016. All observations were obtained with the SpeX spectrograph in prism mode with spectral range from 0.7 to 2.5 microns. They include (4900) Maymelou, (7302) 1993 CQ, (9064) Johndavies, (9531) Jean-Luc, (11341) Babbage, (17480) 1991 PE10, (20171) 1996 WC2, and (25849) 2000 ET107. We present average near-infrared (NIR) reflectance spectra of each asteroid, determine the

  6. Volatiles and the tempo of flood basalt magmatism

    Science.gov (United States)

    Black, Benjamin A.; Manga, Michael

    2017-01-01

    Individual flood basalt lavas often exceed 103 km3 in volume, and many such lavas erupt during emplacement of flood basalt provinces. The large volume of individual flood basalt lavas implies correspondingly large magma reservoirs within or at the base of the crust. To erupt, some fraction of this magma must become buoyant and overpressure must be sufficient to encourage failure and dike propagation. The overpressure associated with a new injection of magma is inversely proportional to the total reservoir volume, and as a large magma body heats the surrounding rocks thermally activated creep will relax isotropic overpressure more rapidly. Here, we examine the viability of buoyancy overpressure as a trigger for continental flood basalt eruptions. We employ a new one-dimensional model that combines volatile exsolution, bubble growth and rise, assimilation, and permeable fluid escape from Moho-depth and crustal chambers. We investigate the temporal evolution of degassing and the eruptibility of magmas using the Siberian Traps flood basalts as a test case. We suggest that the volatile inventory set during mantle melting and redistributed via bubble motion controls ascent of magma into and through the crust, thereby regulating the tempo of flood basalt magmatism. Volatile-rich melts from low degrees of partial melting of the mantle are buoyant and erupt to the surface with little staging or crustal interaction. Melts with moderate volatile budgets accumulate in large, mostly molten magma chambers at the Moho or in the lower crust. These large magma bodies may remain buoyant and poised to erupt-triggered by volatile-rich recharge or external stresses-for ∼106 yr. If and when such chambers fail, enormous volumes of magma can ascend into the upper crust, staging at shallow levels and initiating substantial assimilation that contributes to pulses of large-volume flood basalt eruption. Our model further predicts that the Siberian Traps may have released 1019-1020 g of CO2

  7. Petrogenesis of Late Cenozoic basaltic rocks from southern Vietnam

    Science.gov (United States)

    An, A.-Rim; Choi, Sung Hi; Yu, Yongjae; Lee, Der-Chuen

    2017-02-01

    Major and trace element concentrations, and Sr-Nd-Hf-Pb isotopic compositions of Late Cenozoic (4.1 to 13.8 Ma) basaltic rocks from southern Vietnam have been determined to understand the nature of their mantle source. The volcanic rocks are composed of tholeiite basalt, alkaline basanite, trachybasalt, basaltic trachyandesite, and trachyandesite. The alkaline rocks show light rare earth element (LREE) enrichment, with (La/Yb)N = 10.3-29.8. The tholeiite basalts are distinguished by much lower values (8.8-9.5) of (La/Yb)N. On a primitive mantle-normalized trace element distribution diagram, they show oceanic island basalt (OIB)-like large-ion lithophile element enrichment without high field strength element depletion. However, some samples exhibit positive anomalies in K and Pb and negative anomalies in Sm, suggesting K-rich residual amphibole in the source. The samples contain Sr (87Sr/86Sr = 0.703794-0.704672), Nd (ɛNd = + 1.7-5.7), Hf (ɛHf = + 4.0-10.9), and Pb (206Pb/204Pb = 18.23-18.75; 207Pb/204Pb = 15.53-15.59; 208Pb/204Pb = 38.32-38.88) isotopes, plotting among OIBs, with depleted mid-ocean ridge basalt mantle-enriched mantle type 2 (DMM-EM2) characteristics. There are no discernible isotopic differences between tholeiite and the alkaline series, reflecting the same source. The Nd and Hf isotopic compositions are coupled, and plot along the mantle-crust array, ruling out the possibility of lithospheric mantle in the source. Plots of NiO against the Fo numbers of olivines from the basaltic rocks are within the range of Hainan and Hawaiian basalt olivines, implying that hybrid pyroxenite is present in the source. Also note that the estimated primary melt compositions fall within the experimental field defined by partial melting of silica-poor eclogite and peridotite. The effective melting pressure (Pf) and melting temperature (T) of the primary melts are Pf = 29.6-32.8 kbar and T = 1470-1480 °C. We suggest that Vietnamese basaltic rocks may be produced by

  8. 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

  9. Effect of carbon nanotube addition on the wear behavior of basalt/epoxy woven composites.

    Science.gov (United States)

    Kim, M T; Rhee, K Y; Lee, B H; Kim, C J

    2013-08-01

    The effect of acid-treated carbon nanotube (CNT) addition on the wear and dynamic mechanical thermal properties of basalt/epoxy woven composites was investigated in this study. Basalt/CNT/epoxy composites were fabricated by impregnating woven basalt fibers into epoxy resin mixed with 1 wt% CNTs which were acid-treated. Wear and DMA (dynamic mechanical analyzer) tests were performed on basalt/epoxy composites and basalt/CNT/epoxy composites. The results showed that the addition of the acid-treated CNTs improved the wear properties of basalt/epoxy woven composites. Specifically, the friction coefficient of the basalt/epoxy composite was stabilized in the range of 0.5-0.6 while it fell in the range of 0.3-0.4 for basalt/CNT/epoxy composites. The wear volume loss of the basalt/CNT/epoxy composites was approximately 68% lower than that of the basalt/epoxy composites. The results also showed that the glass transition temperature of basalt/CNT/epoxy composites was higher than that of basalt/epoxy composites. The improvement of wear properties of basalt/epoxy composites by the addition of acid-treated CNTs was caused by the homogeneous load transfer between basalt fibers and epoxy matrix due to the reinforcement of CNTs.

  10. An ancient recipe for flood-basalt genesis.

    Science.gov (United States)

    Jackson, Matthew G; Carlson, Richard W

    2011-07-27

    Large outpourings of basaltic lava have punctuated geological time, but the mechanisms responsible for the generation of such extraordinary volumes of melt are not well known. Recent geochemical evidence suggests that an early-formed reservoir may have survived in the Earth's mantle for about 4.5 billion years (ref. 2), and melts of this reservoir contributed to the flood basalt emplaced on Baffin Island about 60 million years ago. However, the volume of this ancient mantle domain and whether it has contributed to other flood basalts is not known. Here we show that basalts from the largest volcanic event in geologic history--the Ontong Java plateau--also exhibit the isotopic and trace element signatures proposed for the early-Earth reservoir. Together with the Ontong Java plateau, we suggest that six of the largest volcanic events that erupted in the past 250 million years derive from the oldest terrestrial mantle reservoir. The association of these large volcanic events with an ancient primitive mantle source suggests that its unique geochemical characteristics--it is both hotter (it has greater abundances of the radioactive heat-producing elements) and more fertile than depleted mantle reservoirs-may strongly affect the generation of flood basalts.

  11. Similar Microbial Communities Found on Two Distant Seafloor Basalts.

    Science.gov (United States)

    Singer, Esther; Chong, Lauren S; Heidelberg, John F; Edwards, Katrina J

    2015-01-01

    The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR; 9°N). Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from Lō'ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy.

  12. SNOW COVER OF THE CENTRAL ANTARCTICA (VOSTOK STATION AS AN IDEAL NATURAL TABLET FOR COSMIC DUST COLLECTION: PRELIMINARY RESULTS ON THE IDENTIFICATION OF MICROMETEORITES OF CARBONACEOUS CHONDRITE TYPE

    Directory of Open Access Journals (Sweden)

    E. S. Bulat

    2012-01-01

    Full Text Available During the 2010/11 season nearby the Vostok station the 56th Russian Antarctic Expedition has collected surface snow in a big amount from a 3 m deep pit using 15 220 L vol. containers (about 70 kg snow each. Snow melting and processing by ultra-centrifugation was performed in a clean (class 10 000 and 100 laboratory. Total dust concentrations were not exceeded 37.4 mkg per liter with particle dispersal mode around 2.5 mkm. To analyze the elemental composition of fine dust particles aimed to reveal Antarctic micrometeorites (AMM two electron microscopy devices equipped with different micro-beams were implemented. As a preliminary result, three particles (of 107 analyzed featured by Mg content clearly dominated over Al along with Si and Fe as major elements (a feature of carbonaceous chondrites were observed. By this the Vostok AMM CS11 collection was established. The occurrence of given particles was averaged 2.8% – the factual value obtained for the first time for chondritic type AMM at Vostok which should be considered as the lowest estimate for all other families of AMM. Given the reference profile of total dust content in East Antarctic snow during Holocene (18 mkg/kg the MM deposition in Antarctica was quantified for the first time – 14 tons per day for carbonaceous chondrites for the Vostok AMM CS11 collection and up to 245 tons per day for all MM types for the Concordia AMM DC02 collection. The results obtained allowed to prove that snow cover (ice sheet in total of Central East Antarctica is the best spot (most clean of other natural locations and always below 0 ºC for collecting native MM deposited on the Earth during the last million years and could be useful in deciphering the origin and evolution of solid matter in our Solar System and its effects on Earth-bound biogeochemical and geophysical processes including the life origin. The farther analyses of the Vostok AMMs are in a progress.

  13. Trivalent expanders and hyperbolic surfaces

    CERN Document Server

    Ivrissimtzis, Ioannis; Vdovina, Alina

    2012-01-01

    We introduce a family of trivalent expanders which tessellate compact hyperbolic surfaces with large isometry groups. We compare this family with Platonic graphs and modifications of them and prove topological and spectral properties of these families.

  14. Investigation of basalt plastic reinforcement and its Adhesion with Concrete

    Directory of Open Access Journals (Sweden)

    Kustikova Yulia Olegovna

    2014-03-01

    Full Text Available The load-bearing capacity and durability of concrete structures with metal or other reinforcement depends on their physical and mechanical properties and adhesion values with concrete. In this regard, there is an urgent need in the definition of adhesion of basalt reinforcement and concrete of various compositions and classes. One of the main problems with the use of basalt rods in concrete structures is - providing a high degree of load-carrying capacity in different conditions of stress-strain state of the structure, and the related amount of its adhesion with concrete. Meeting these requirements can be achieved with load-bearing capacity of individual rods, adhesion value, in general, of basalt reinforcement with concrete.

  15. Basalt Thickness in Mare Humorum: New Method and Results

    Science.gov (United States)

    Budney, C. J.; Lucey, P. G.

    1996-03-01

    Basalt thicknesses in mare basins have been determined using assumptions about the pre-mare topography of partly buried craters. Differences in those assumptions have led to a factor of two difference in mare thickness estimates. Further, knowledge of thickness is restricted to areas in which buried craters are present. We have shown that craters in the mare sometimes excavate highland material from below the mare cover. Using such craters, and assumptions about their depth of excavation, we can obtain independent estimates of basalt thickness. This method allows testing of pre-mare crater topography models employed in the buried crater method, adds significantly more data points for development of isopach maps, and allows determining of thickness of stratigraphic layers other than mare basalts such as melt sheets where compositional contrast is present.

  16. Evidence against hydrogen-based microbial ecosystems in basalt aquifers

    Science.gov (United States)

    Anderson; Chapelle; Lovley

    1998-08-14

    It has been proposed that hydrogen produced from basalt-ground-water interactions may serve as an energy source that supports the existence of microorganisms in the deep subsurface on Earth and possibly on other planets. However, experiments demonstrated that hydrogen is not produced from basalt at an environmentally relevant, alkaline pH. Small amounts of hydrogen were produced at a lower pH in laboratory incubations, but even this hydrogen production was transitory. Furthermore, geochemical considerations suggest that previously reported rates of hydrogen production cannot be sustained over geologically significant time frames. These findings indicate that hydrogen production from basalt-ground-water interactions may not support microbial metabolism in the subsurface.

  17. Petrogenesis of pillow basalts from Baolai in southwestern Taiwan

    Science.gov (United States)

    Liu, Chih-Chun; Yang, Huai-Jen

    2016-04-01

    The pillow basalts from Baolai in southwestern Taiwan have been inferred to bear Dupal signautres based on their Th/Ce ratio, linking the Baolai basalts to the South China Sea (SCS) seamounts that are characterized by Dupal Pb isotope signatures (Smith and Lewis, 2007). In this study, thirty-two Baolai basalt samples were analyzed for abundances of major and trace elements as well as Pb and Nd isotope ratios to verify their Dupal characters and to constrain their petrogenesis significance. The Baolai basalts contain 4-10 % L.O.I.. Three stages of alteration are inferred from plots of L.O.I. abundance versus concentrations major oxides as well as mineral textures and compositions. The first alteration stage was characterized by albitization that converted Ca-rich plagioclase to albite. The second alteration stage was dominated by chloritization of olivine and augite, resulting in increases in L.O.I. abundance. The last alteration stage is represented by formation of secondary calcite in vesicles and cracks. These alteration processes reflect interaction with seawater and apparently did not affect the magmatic Pb isotope composition for the low Pb concentration in seawater. Relative to the North Hemisphere Reference Line (NHRL), the Baolai pillow basalts have higher 208Pb/204Pb ratios at a given 206Pb/204Pb value, showing Dupal anomaly. For their relatively higher 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb ratios, the Baolai basalts are distinct from majority of the Cenozoic basalts in the Hainan-Leizhou peninsula, the Indochina peninsula, and the SCS seamounts, for which derivation from the Hainan mantle plume has been recently proposed (Wang et al., 2013). In contrast, the Baolai basalts and the Cenozoic basalts from eastern Guangdong at southeastern China have similar Pb and Nd isotope compositions, indicating derivation from similar mantle sources. However, the Baolai basalts have lower abundance ratios of Zr/Hf (40.3-45.6 versus 46.5-50.5), La/Yb (12

  18. Basalt fiber reinforced polymer composites: Processing and properties

    Science.gov (United States)

    Liu, Qiang

    A high efficiency rig was designed and built for in-plane permeability measurement of fabric materials. A new data derivation procedure to acquire the flow fluid pattern in the experiment was developed. The measurement results of the in-plane permeability for basalt twill 31 fabric material showed that a high correlation exists between the two principal permeability values for this fabric at 35% fiber volume fraction. This may be the most important scientific contribution made in this thesis. The results from radial measurements corresponded quite well with those from Unidirectional (UD) measurements, which is a well-established technique. No significant differences in mechanical properties were found between basalt fabric reinforced polymer composites and glass composites reinforced by a fabric of similar weave pattern. Aging results indicate that the interfacial region in basalt composites may be more vulnerable to environmental damage than that in glass composites. However, the basalt/epoxy interface may have been more durable than the glass/epoxy interface in tension-tension fatigue because the basalt composites have significantly longer fatigue life. In this thesis, chapter I reviews the literature on fiber reinforced polymer composites, with concentration on permeability measurement, mechanical properties and durability. Chapter II discusses the design of the new rig for in-plane permeability measurement, the new derivation procedure for monitoring of the fluid flow pattern, and the permeability measurement results. Chapter III compares the mechanical properties and durability between basalt fiber and glass fiber reinforced polymer composites. Lastly, chapter IV gives some suggestions and recommendations for future work.

  19. Seismic wave propagation through an extrusive basalt sequence

    Science.gov (United States)

    Sanford, Oliver; Hobbs, Richard; Brown, Richard; Schofield, Nick

    2016-04-01

    Layers of basalt flows within sedimentary successions (e.g. in the Faeroe-Shetland Basin) cause complex scattering and attenuation of seismic waves during seismic exploration surveys. Extrusive basaltic sequences are highly heterogeneous and contain strong impedance contrasts between higher velocity crystalline flow cores (˜6 km s-1) and the lower velocity fragmented and weathered flow crusts (3-4 km s-1). Typically, the refracted wave from the basaltic layer is used to build a velocity model by tomography. This velocity model is then used to aid processing of the reflection data where direct determination of velocity is ambiguous, or as a starting point for full waveform inversion, for example. The model may also be used as part of assessing drilling risk of potential wells, as it is believed to constrain the total thickness of the sequence. In heterogeneous media, where the scatter size is of the order of the seismic wavelength or larger, scattering preferentially traps the seismic energy in the low velocity regions. This causes a build-up of energy that is guided along the low velocity layers. This has implications for the interpretation of the observed first arrival of the seismic wave, which may be a biased towards the low velocity regions. This will then lead to an underestimate of the velocity structure and hence the thickness of the basalt, with implications for the drilling of wells hoping to penetrate through the base of the basalts in search of hydrocarbons. Using 2-D acoustic finite difference modelling of the guided wave through a simple layered basalt sequence, we consider the relative importance of different parameters of the basalt on the seismic energy propagating through the layers. These include the proportion of high to low velocity material, the number of layers, their thickness and the roughness of the interfaces between the layers. We observe a non-linear relationship between the ratio of high to low velocity layers and the apparent velocity

  20. Near-Primary Oxidized Basalts from the Submarine Vanuatu Arc

    Science.gov (United States)

    Gentes, Z.; Kelley, K. A.; Cottrell, E.; Arculus, R. J.

    2014-12-01

    Near-primary melt compositions (i.e., in equilibrium with >Fo89 olivine) are rare in arc systems. Yet, such melts provide essential views of mantle-derived melts, without further modification by fractional crystallization or other crustal processes, and reveal the diversity of melt compositions that exist in the arc mantle wedge. Here, we present new measurements of naturally glassy, near-primary olivine-hosted melt inclusions from one dredge of Evita seamount (SS07/2008 NLD-02) in the southern Vanuatu arc system. Two distinct basalt types were identified in hand sample upon collection, based on contrasting phenocryst assemblage (Type 1: 1% phenocrysts; Type 2: 15% phenocrysts). We selected melt inclusions from each type and determined major elements, S, and Cl by EMP, H2O and CO2 by FTIR, trace elements by LA-ICP-MS, and Fe3+/∑Fe ratios by XANES. Melt inclusions from both lava types show equilibrium with ≥Fo90 olivine, consistent with host olivine compositions, and thus are near-primary melt compositions that have escaped major modification since departing the mantle wedge. Both have similar maximum dissolved H2O (~2.3 wt.%), high Mg# (48-75), and are basalt to basaltic andesite (SiO2 49-55 wt.%). However, the two lava types have very different major and trace element compositions. Inclusions from Type 1 show relatively flat REE patterns and classic negative anomalies in Nb and Ta, and positive anomalies in Pb and Sr typical of normal arc basalts, and have Fe3+/∑Fe ratios similar to global arc basalts (~0.24). In contrast, melt inclusions from Type 2 exhibit steeply sloped REE patterns with strong depletions in the HREE that suggest garnet in the source lithology for these magmas, either in the subducting slab or the mantle wedge. Moreover, the Type 2 inclusions have high La/Yb (29.5-43) and Sr/Y (50-58), which are classically attributed to partial melting of the basaltic slab, although these inclusions are basaltic, not andesitic. Type 2 inclusions also

  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

    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...... 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...

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

    DEFF Research Database (Denmark)

    Søager, Nina

    The extensive Quaternary volcanism in the Payenia volcanic province, Mendoza, Argentina, is investigated in this study by major and trace element analyses, Sr, Nd, Hf and Pb-isotopic analyses and Zr-Hf isotope dilution data on samples from almost the entire province. The samples are mainly...... 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...

  3. 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...

  4. Loading-unloading test analysis of anisotropic columnar jointed basalts

    Institute of Scientific and Technical Information of China (English)

    Zhi-gang SHAN; Sheng-jie DI

    2013-01-01

    To evaluate the columnar jointed basalts in the dam site of Baihetan hydropower station in southwest China,we developed a basic conceptual model of single jointed rock mass.Considering that the rock mass deformation consists of rock block deformation and joints deformation,the linear mechanical characteristics of the cell(including the elastic joints and the nonlinear mechanical behaviors of the cell)with a combined frictional-elastic interface were analyzed.We developed formulas to calculate the rock block deformation,which can be adapted for multiple jointed rock mass and columnar jointed basalts.The formulas are effective in calculating the equivalent modulus of multiple jointed rock mass,and precisely reveal the anisotropic properties of columnar jointed basalts.Furthermore,the in situ rigid bearing plate tests were analyzed and calculated,and the types of loading-unloading curves and the equivalent modulus along different directions of columnar jointed basalts were obtained.The analytical results are in close compliance with the test results.

  5. Genetic aspects of basalts from the Carlsberg Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    of the CR rocks are sparse. The bulk chemical, mineral chemical and ore mineralization aspects of the dredged basalts from a segment of the CR (at 3°37¢N, 64°57¢E) are synthesized to indicate the influence of fractional crystallization coupled with magma...

  6. Interpreting chemical compositions of small scale basaltic systems: A review

    Science.gov (United States)

    McGee, Lucy E.; Smith, Ian E. M.

    2016-10-01

    Small scale basaltic magmatic systems occur in all of the major tectonic environments of planet Earth and are characteristically expressed at the Earth's surface as fields of small monogenetic cones. The chemical compositions of the materials that make up these cones reflect processes of magma generation and differentiation that occur in their plumbing system. The volumes of magmas involved are very small and significantly their compositional ranges reveal remarkably complex processes which are overwhelmed or homogenized in larger scale systems. Commonly, compositions are basaltic, alkalic and enriched in light rare earth elements and large ion lithophile elements, although the spectrum extends from highly enriched nephelinites to subalkalic and tholeiitic basalts. Isotopic analyses of rocks from volcanic fields almost always display compositions which can only be explained by the interaction of two or more mantle sources. Ultimately their basaltic magmas originate by small scale melting of mantle sources. Compositional variety is testament to melting processes at different depths, a range of melting proportions, a heterogeneous source and fractionation, magma mixing and assimilation within the plumbing system that brings magmas to the surface. The fact that such a variety of compositions is preserved in a single field shows that isolation of individual melting events and their ascent is an important and possibly defining feature of monogenetic volcanism, as well as the window their chemical behavior provides into the complex process of melt generation and extraction in the Earth's upper mantle.

  7. 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)

  8. Basalt near-surface test facility test plans

    Energy Technology Data Exchange (ETDEWEB)

    Krug, A.D.

    1979-06-01

    The NSTF is under construction at Gable Mountain for in-situ testing, which will be conducted in two phases: Phase I, using electric heaters to simulate nuclear waste canisters in order to study the thermomechanical response of basalt; and Phase II, using spent fuel canisters. The tests planned for Phases I and II are described. (DLC)

  9. [The dust factor in the manufacture of basalt fibers].

    Science.gov (United States)

    Gorban', L N; Riazanov, A V; Voloboeva, A A; Rybak, E A

    1996-01-01

    A study was made of the labour conditions of those workers engaged in the production of basalt fibre (BF). Morphological makeup is examined as is dispersity and cytotoxicity of the dust produced in the process of BF making. An issue is addressed of usefulness of setting special hygienic regulations for BF dust.

  10. Notice of Release of NBR-1 Germplasm Basalt Milkvetch

    Science.gov (United States)

    Basalt milkvetch or threadstalk milkvetch (Astragalus filipes Torr. ex A. Gray) is a perennial legume that is widely distributed on rangelands in western North America and holds promise for rangeland revegetation and restoration programs. No germplasms or cultivars are commercially available for ba...

  11. 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...

  12. BASALT CARBONATION AND ITS POTENTIAL USE IN CO2 STORAGE

    Directory of Open Access Journals (Sweden)

    Patricia Carneiro

    2013-03-01

    Full Text Available The increasing levels of CO2 in the atmosphere are indicated as a major contributor to the enhanced greenhouse effect. There are several options to reduce these levels and the Carbon Capture and Storage (CCS is identified as an effective way to decrease the concentration of this gas. In this work, it is present the indirect carbonation of basalt, as well as, a study of abundance and occurrence of this mineral and its proximity to emission sources of CO2 . After examining the map constructed by matching Brazilian regions with high emission and regions where there are basalt occurrences, one can conclude that the South and Southeast regions have a great potential for geological storage into basalt. This is due to the occurrence of emission sources very close to the basalt area. The carbonation reaction is efficient, as evidenced by atomic absorption analysis, showing a high rate of conversion of leached ions into carbonate. SEM and EDS analysis indicate the formation of precipitated ferrous calcite, which suggests an efficient indirect carbonation.

  13. Gas adsorption on crushed quartz and basalt. [in vacuum

    Science.gov (United States)

    Barker, C.; Torkelson, B. E.

    1975-01-01

    The new surfaces generated by crushing rocks and minerals adsorb gases. Different gases are adsorbed to different extents so that both the total amount and composition of the released gases are changed. This affects the interpretation of the composition of the gases obtained by vacuum crushing lunar basalts, meteorites and minerals with fluid inclusions.

  14. 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.

  15. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test.

  16. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation

    OpenAIRE

    Jeong-Il Choi; Bang Yeon Lee

    2015-01-01

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber’s suitability as a reinforcing fiber. Single fiber pullout tests were performed and then th...

  17. Crystallization of pyroxenes in lunar KREEP basalt 15386 and meteoritic basalts

    Science.gov (United States)

    Takeda, H.; Ishii, T.; Miyamoto, M.; Duke, M. B.

    1978-01-01

    Single crystal X-ray diffraction studies and electron microprobe analyses of pyroxenes from the meteorites Pasamonte, Yamato 74450 and Yamato 74159 and in lunar KREEP basalt 15386 show similarities of pyroxene crystallization history. They each began crystallization with magnesian pyroxene (pigeonite in the meteorites, orthopyroxene in 15386) followed by strong zonation toward iron-rich and calcium-rich compositions. These data appear to be understandable in terms of dynamic crystallization experiments on liquids of similar composition to the meteorites. In contrast, pyroxene compositions in the meteorites Juvinas, Sioux County and Nuevo Laredo lie along an apparent tie line between calcium-poor and calcium-rich end members with no iron-enrichment trend. In Sioux County and Juvinas, the primary pyroxene is calcium-poor, with exsolved augite. In Nuevo Laredo, pigeonite and augite occur as separate grains with exsolution of augite in the pigeonite. The development of prominent exsolution lamellae is consistent with a long thermal annealing after the primary crystallization event, which may also explain the absence of iron/magnesium zonation in the pigeonites.

  18. Plant-induced weathering of a basaltic rock: experimental evidence

    Science.gov (United States)

    Hinsinger, Philippe; Fernandes Barros, Omar Neto; Benedetti, Marc F.; Noack, Yves; Callot, Gabriel

    2001-01-01

    The active role of higher plants in the weathering of silicate minerals and rocks is still a question for debate. The present work aimed at providing experimental evidence of the important role of a range of crop plants in such processes. In order to quantitatively assess the possible effect of these diverse plant species on the weathering of a basaltic rock, two laboratory experiments were carried out at room temperature. These compared the amounts of elements released from basalt when leached with a dilute salt solution in the presence or absence of crop plants grown for up to 36 days. For Si, Ca, Mg, and Na, plants resulted in an increase in the release rate by a factor ranging from 1 to 5 in most cases. Ca and Na seemed to be preferentially released relative to other elements, suggesting that plagioclase dissolved faster than the other constituents of the studied basalt. Negligible amounts of Fe were released in the absence of plants as a consequence of the neutral pH and atmospheric pO 2 that were maintained in the leaching solution. However, the amounts of Fe released from basalt in the presence of plants were up to 100- to 500-fold larger than in the absence of plants, for banana and maize. The kinetics of dissolution of basalt in the absence of plants showed a constantly decreasing release rate over the whole duration of the experiment (36 days). No steady state value was reached both in the absence and presence of banana plants. However, in the latter case, the rates remained at a high initial level over a longer period of time (up to 15 days) before starting to decrease. For Fe, the maximum rate of release was reached beyond 4 days and this rate remained high up to 22 days of growth of banana. The possible mechanisms responsible for this enhanced release of elements from basalt in the presence of plants are discussed. Although these mechanisms need to be elucidated, the present results clearly show that higher plants can considerably affect the kinetics

  19. Federal government expands compliance initiatives.

    Science.gov (United States)

    Dugan, J K

    1997-09-01

    In 1995, the Federal government initiated Operation Restore Trust to increase enforcement of fraud and abuse regulations in Medicare and Medicaid programs. With the success of the original initiative, the government is expanding the project to additional states and program areas. The initial scrutiny of home health agencies, nursing homes, hospice care, and durable medical equipment is being expanded to managed care plans and acute care hospitals with an eye toward DRG creep. To manage this increased enforcement activity, healthcare organizations should institute comprehensive corporate compliance programs. Such programs should provide a framework that delineates responsibilities and provides a systematic means to resolve issues in a timely manner.

  20. Carbon fixation by basalt-hosted microbial communities

    Directory of Open Access Journals (Sweden)

    Beth N Orcutt

    2015-09-01

    Full Text Available Oceanic crust is a massive potential habitat for microbial life on Earth, yet our understanding of this ecosystem is limited due to difficulty in access. In particular, measurements of rates of microbial activity are sparse. We used stable carbon isotope incubations of crustal samples, coupled with functional gene analyses, to examine the potential for carbon fixation on oceanic crust. Both seafloor-exposed and subseafloor basalts were recovered from different mid-ocean ridge and hot spot environments (i.e., the Juan de Fuca Ridge, the Mid-Atlantic Ridge, and the Loihi Seamount and incubated with 13C-labeled bicarbonate. Seafloor-exposed basalts revealed incorporation of 13C-label into organic matter over time, though the degree of incorporation was heterogeneous. The incorporation of 13C into biomass was inconclusive in subseafloor basalts. Translating these measurements into potential rates of carbon fixation indicated that 0.1 – 10 nmol C g-1rock d-1 could be fixed by seafloor-exposed rocks. When scaled to the global production of oceanic crust, this suggests carbon fixation rates of 10^9 – 10^12 g C yr-1, which matches earlier predictions based on thermodynamic calculations. Functional gene analyses indicate that the Calvin cycle is likely the dominant biochemical mechanism for carbon fixation in basalt-hosted biofilms, although the reductive acetyl-CoA pathway and reverse TCA cycle likely play some role in net carbon fixation. These results provide empirical evidence for autotrophy in oceanic crust, suggesting that basalt-hosted autotrophy could be a significant contributor of organic matter in this remote and vast environment.

  1. Alkali norite, troctolites, and VHK mare basalts from breccia 14304

    Science.gov (United States)

    Goodrich, Cyrena Anne; Taylor, G. Jeffrey; Keil, Klaus; Kallemeyn, Gregory W.; Warren, Paul H.

    1986-09-01

    Twelve clasts were separated from breccia 14304 for consortium study: six pristine highlands rocks, two mare basalts, and four nonpristine highlands rocks. The pristine highlands rocks include representatives of the magnesian troctolite-anorthosite and alkali suites, the two most common subgroups of the Mg suite found at the Apollo 14 site. Two troctolite clasts have olivine (~Fo 90) and plagioclase (~An 94) compositions similar to one group of Apolo 14 troctolites. One also contains spinel (Mg' 66-85). Incompatible element abundances in one are similar to those of 14305 troctolites, although the HREE (heavy rare earth elements) pattern is distinct among Apollo 14 troctolites. A dunite clast (~Fo 89) may be an unrepresentative piece of a troctolite. Alkali lithologies include an alkali anorthosite and an alkali norite, which is a rock type not previously described. The alkali norite has a pristine igneous texture and contains inverted pigeonite (Mg' 64), plagioclase (An82), K-feldspar, ternary feldspar, REE-rich phosphates, and silica. It resembles alkali gabbronorites from Apollo 14 and 67975 in mineralogy and mineral compositions. Alkali lithologies and phosphate-bearing magnesian anorthosites from Apollo 14 may have formed from Mg-rich magmas that assimilated various amounts of material rich in P and REE. This material could be a fractionated derivative of urKREEP. another pristine clast from 14304 is an Mg-gabbronorite. The two mare basalt clasts are very high potassium (VHK) basalts. They have 4 mg/g K and K/La ratios of 580 and 700. The parent magmas of VHK basalts could have formed from typical low-Ti, high-Al basaltic magmas by assimilation of K-rich material. This material could also be a fractionated derivative or urKREEP. Nonpristine 14304 clasts include melt-textured anorthosites and an augite-rich poikilitic melt rock. The latter is probably polymict, but its major component must be an Mg-suite gabbro.

  2. Carbon fixation by basalt-hosted microbial communities.

    Science.gov (United States)

    Orcutt, Beth N; Sylvan, Jason B; Rogers, Daniel R; Delaney, Jennifer; Lee, Raymond W; Girguis, Peter R

    2015-01-01

    Oceanic crust is a massive potential habitat for microbial life on Earth, yet our understanding of this ecosystem is limited due to difficulty in access. In particular, measurements of rates of microbial activity are sparse. We used stable carbon isotope incubations of crustal samples, coupled with functional gene analyses, to examine the potential for carbon fixation on oceanic crust. Both seafloor-exposed and subseafloor basalts were recovered from different mid-ocean ridge and hot spot environments (i.e., the Juan de Fuca Ridge, the Mid-Atlantic Ridge, and the Loihi Seamount) and incubated with (13)C-labeled bicarbonate. Seafloor-exposed basalts revealed incorporation of (13)C-label into organic matter over time, though the degree of incorporation was heterogeneous. The incorporation of (13)C into biomass was inconclusive in subseafloor basalts. Translating these measurements into potential rates of carbon fixation indicated that 0.1-10 nmol C g(-1) rock d(-1) could be fixed by seafloor-exposed rocks. When scaled to the global production of oceanic crust, this suggests carbon fixation rates of 10(9)-10(12) g C year(-1), which matches earlier predictions based on thermodynamic calculations. Functional gene analyses indicate that the Calvin cycle is likely the dominant biochemical mechanism for carbon fixation in basalt-hosted biofilms, although the reductive acetyl-CoA pathway and reverse TCA cycle likely play some role in net carbon fixation. These results provide empirical evidence for autotrophy in oceanic crust, suggesting that basalt-hosted autotrophy could be a significant contributor of organic matter in this remote and vast environment.

  3. Assessing microstructures of pyrrhotites in basalts by multifractal analysis

    Directory of Open Access Journals (Sweden)

    S. Xie

    2010-07-01

    Full Text Available Understanding and describing spatial arrangements of mineral particles and determining the mineral distribution structure are important to model the rock-forming process. Geometric properties of individual mineral particles can be estimated from thin sections, and different models have been proposed to quantify the spatial complexity of mineral arrangement. The Gejiu tin-polymetallic ore-forming district, located in Yunnan province, southwestern China, is chosen as the study area. The aim of this paper is to apply fractal and multifractal analysis to quantify distribution patterns of pyrrhotite particles from twenty-eight binary images obtained from seven basalt segments and then to discern the possible petrological formation environments of the basalts based on concentrations of trace elements. The areas and perimeters of pyrrhotite particles were measured for each image. Perimeter-area fractal analysis shows that the perimeter and area of pyrrhotite particles follow a power-law relationship, which implies the scale-invariance of the shapes of the pyrrhotites. Furthermore, the spatial variation of the pyrrhotite particles in space was characterized by multifractal analysis using the method of moments. The results show that the average values of the area-perimeter exponent (DAP, the width of the multifractal spectra (Δ(D(0−D(2 and Δ(D(qminD(qmax and the multifractality index (τ"(1 for the pyrrhotite particles reach their minimum in the second basalt segment, which implies that the spatial arrangement of pyrrhotite particles in Segment 2 is less heterogeneous. Geochemical trace element analysis results distinguish the second basalt segment sample from other basalt samples. In this aspect, the fractal and multifractal analysis may provide new insights into the quantitative assessment of mineral microstructures which may be closely associated with the petrogenesis as shown by the

  4. Geochemistry of Two Types of Basalts in the Emeishan Basaltic Province: Evidence for Mantle Plume-Lithosphere Interaction

    Institute of Scientific and Technical Information of China (English)

    张招崇; 王福生

    2002-01-01

    Based on the temporal-spatial distribution and geochemical characteristics, the Emeishan basalts can be divided into two types: high-P2O-TiO2 basalt (HPT) and low-P2O5-TiO2 basalt (LPT), which differ distinctly in geochemistry: the LPTs are characterized by relatively high abundances of MgO, total FeO and P2O5 and compatible elements (Cr, Ni, Sc), and relatively low contents of moderately compatible elements (V, Y, Yb, Co), LREE and other incompatible elements compared with the HPT. On the diagrams of trace element ratios, they are plotted on an approximately linear mixing line between depleted and enriched mantle sources, suggesting that these two types of basalts resulted from interactions of varying degrees between mantle plume and lithospheric mantle containing such volatile-rich minerals as amphibole and apatite. The source region of the LPT involves a smaller proportion of lithospheric components, while that of the HTP has a larger proportion of lithospheric components. Trachyte is generated by partial melting of the basic igneous rocks at the base of the lower continental crust. Both the two types of magmas underwent certain crystal fractionation and contamination of the lower crust at high-level magma chambers and en route to the surface.

  5. Zr and Nb partition coefficients - Implications for the genesis of mare basalts, KREEP, and sea floor basalts

    Science.gov (United States)

    Mccallum, I. S.; Charette, M. P.

    1978-01-01

    The distribution coefficients of Zr and Nb have been found between armalcolite, ilmenite, clinopyroxene, rutile, plagioclase, and a coexisting high-Ti mare basalt melt in the 1105-1128 C temperature range. Henry's Law is not broken over the compositional range evaluated. The distribution coefficients of clinopyroxene are strongly dependent on melt and crystal compositions. The Al2O3 activity in the melt is a strong controlling parameter. It is concluded that: (1) Apollo 11 (low K) and Apollo 17 high-Ti mare basalts may have been generated by the partial melting of an ilmenite-rich cumulate, (2) Apollo 11 (high K) basalts may have been generated by a small amount of partial melting of a more fractionated ilmenite-rich cumulate, (3) KREEP magmas may have been formed as residual melts produced by fractional crystallization of the lunar magma ocean, and (4) anomalous (type II) MOR basalts may have been generated by small degrees of partial melting of a relatively undepleted mantle with clinopyroxene remaining in the residium.

  6. Expanding the eukaryotic genetic code

    Science.gov (United States)

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2013-01-22

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  7. Expanding the eukaryotic genetic code

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2017-02-28

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  8. ERBU, Expanding Rubber Band Universe

    CERN Document Server

    Soares, Domingos

    2015-01-01

    I put forward a simple unidimensional mechanical analogue of the three-dimensional universe models of modern relativistic cosmology. The main goal of the proposal is the appropriate appreciation of the intrinsic relationship between Hubble's law and the homogeneity of expanding relativistic models.

  9. Expandable Shelter/Container Report.

    Science.gov (United States)

    1973-06-01

    without removing whatever payload might be in the contai ner. Equ i pment located in the expanded porti on of the ES/C durin g norma l operat i ons is...and Supply BattalIon , Div isi on Support Coianand. In addition , divisional avIation battalions have an A Irc raft Maintenance Company. The TOE

  10. Late Permian basalts in the Yanghe area, eastern Sichuan Province, SW China: Implications for the geodynamics of the Emeishan flood basalt province and Permian global mass extinction

    Science.gov (United States)

    Li, Hongbo; Zhang, Zhaochong; Santosh, M.; Lü, Linsu; Han, Liu; Liu, Wei

    2017-02-01

    We report the finding of a ∼20 m thick sequence of massive pyroxene-plagioclase-phyric basalt lava flows in the Yanghe area of the northeastern Sichuan Basin, within the Yangtze craton of SW China, which were previously considered to be located outside the Emeishan flood basalt province. This basaltic sequence above the middle Permian Maokou Formation (Fm.) is overlain by the late Permian Longtan Fm. Thus, the Yanghe basalts should be stratigraphically correlated with the Emeishan flood basalts. The Yanghe basalts show typical oceanic island basalt (OIB) affinity, and geochemically resemble Emeishan basalts, especially in the case of high-Ti (HT) basalts from the eastern domain of the Emeishan flood basalt province. The rocks have low age-corrected (87Sr/86Sr)t (t = 260 Ma) ratios (0.704158-0.704929) and Pb isotopic ratios [206Pb/204Pb(t) (18.264-18.524), 207Pb/204Pb(t) (15.543-15.58), and 208Pb/204Pb(t) (38.147-38.519)], and positive εNd(t) values (+3.15 to +3.61), suggesting that the lavas have not undergone any significant crustal contamination. The crystallization temperature of clinopyroxene is estimated to be 1368-1420 °C, suggesting anomalously thermal inputs from a mantle source and a possible plume-head origin. The fractionation of middle rare earth elements (MREE) to heavy REE (HREE) suggests that these rocks were produced by small degrees of partial melting of mantle peridotite within the garnet-spinel transition region. The stratigraphic relationships and similar geochemical signatures with the Emeishan flood basalts suggest that the Yanghe basalts are part of the Emeishan flood basalt province and can be considered as the northeastern limit of the Emeishan flood basalt province. Our finding extends the diameter of the Emeishan flood basalt province to ∼1200-1400 km, covering an area of up to ∼7 × 105 km2, two times more than previously estimated. The larger areal extent and giant eruption volume, incorporating the Sichuan Basin, lend support

  11. Mechanical characteristics of fused cast basalt tube encased in steel pipe for protecting steel surface

    Institute of Scientific and Technical Information of China (English)

    Jee-Seok WANG; Jong-Do KIM; Hee-Jong YOON

    2009-01-01

    Because of the various excellent characteristics of cast basalt materials, such as, anti-corrosion, anti-wearing, good hardness, high chemical stability, of which steel may not possess, the steel-basalt composite pipes are used in severe environments for compensating the defects of steel. The limit of bending moment with which steel-basalt composite pipe may safely endure was calculated and the limit curvature of the composite pipe in the safe range was presented. The application temperature of steel-basalt pipe was examined due to a different coefficient among basalt, mortar and mild steel.

  12. Melt Segregation & LPO in Anorthite-Basalt Deformed in Torsion

    Science.gov (United States)

    Zimmerman, M. E.; Kohlstedt, D. L.

    2003-12-01

    Deformation in the middle and lower crust is in large part controlled by the rheology of feldspar. Seismic studies have shown that the middle crust of orogenic belts is partially molten. Structural studies of mylonites and migmatites from these terrains record large strain deformation. Therefore, we performed torsional shear deformation experiments on fine grained (10 μ m) samples of Beaver Bay anorthite (An70) +/- 10 vol% basalt to shear strains γ = 2-6 to investigate the development of lattice preferred orientation (LPO) and melt segregation at large shear strains. We performed experiments in a gas medium apparatus equipped with an internal torque cell at T = 1450 K, P = 300 MPa, and constant twist rate. Melt segregated in the An70 + basalt samples into melt-rich bands oriented at ˜20° to the shear plane and antithetic to the shear direction. The spacing between bands is ˜0.5 mm. Distortion of the iron jacket demonstrates that strain localized in the melt-rich bands. We determined the LPO of An70 with scanning electron microscopy using electron back scatter diffraction (SEM-EBSD). In patterns from an An70+ basalt sample deformed to γ ≈ 2.5, (001) planes are aligned subparallel to the shear plane and [100] axes are concentrated close to the shear direction. Both the (001) and the [100] are rotated counter clockwise from the shear direction by 20-25° . The formation of melt-rich bands is consistent with results from simple shear experiments on olivine + chromite + basalt and olivine + FeS +/- basalt, as well as An70 + basalt and indicates that deformation can drive melt segregation. Deformation drives the self organization of melt-rich bands and decreases the effective viscosity of the rock. The LPO is consistent with results from experiments on albite in shear and anorthite in compression and compatible with slip dominantly on (001) with [100] as the slip direction. A similar back rotation, attributed to partitioning of the strain between melt-rich and

  13. Similarities in basalt and rhyolite lava flow emplacement processes

    Science.gov (United States)

    Magnall, Nathan; James, Mike; Tuffen, Hugh; Vye-Brown, Charlotte

    2016-04-01

    Here we use field observations of rhyolite and basalt lava flows to show similarities in flow processes that span compositionally diverse lava flows. The eruption, and subsequent emplacement, of rhyolite lava flows is currently poorly understood due to the infrequency with which rhyolite eruptions occur. In contrast, the emplacement of basaltic lava flows are much better understood due to very frequent eruptions at locations such as Mt Etna and Hawaii. The 2011-2012 eruption of Cordón Caulle in Chile enabled the first scientific observations of the emplacement of an extensive rhyolite lava flow. The 30 to 100 m thick flow infilled a topographic depression with a negligible slope angle (0 - 7°). The flow split into two main channels; the southern flow advanced 4 km while the northern flow advanced 3 km before stalling. Once the flow stalled the channels inflated and secondary flows or breakouts formed from the flow front and margins. This cooling rather than volume-limited flow behaviour is common in basaltic lava flows but had never been observed in rhyolite lava flows. We draw on fieldwork conducted at Cordón Caulle and at Mt Etna to compare the emplacement of rhyolite and basaltic flows. The fieldwork identified emplacement features that are present in both lavas, such as inflation, breakouts from the flow font and margins, and squeeze-ups on the flow surfaces. In the case of Cordón Caulle, upon extrusion of a breakout it inflates due to a combination of continued lava supply and vesicle growth. This growth leads to fracturing and breakup of the breakout surface, and in some cases a large central fracture tens of metres deep forms. In contrast, breakouts from basaltic lava flows have a greater range of morphologies depending on the properties of the material in the flows core. In the case of Mt Etna, a range of breakout morphologies are observed including: toothpaste breakouts, flows topped with bladed lava as well as breakouts of pahoehoe or a'a lava. This

  14. 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

  15. 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.

  16. 47 CFR 64.1401 - Expanded interconnection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Expanded interconnection. 64.1401 Section 64...) MISCELLANEOUS RULES RELATING TO COMMON CARRIERS Expanded Interconnection § 64.1401 Expanded interconnection. (a... 69, subpart G of this chapter, shall offer expanded interconnection for interstate special...

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

    Energy Technology Data Exchange (ETDEWEB)

    Asfahani, Jamal, E-mail: cscientific2@aec.org.s [Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2011-03-15

    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.

  18. Automated interpretation of nuclear and electrical well loggings for basalt characterization (case study from southern Syria).

    Science.gov (United States)

    Asfahani, J; Abdul Ghani, B

    2012-10-01

    Nuclear well logging, including natural gamma ray, density and neutron-porosity techniques are used with electrical well logging of long and short normal techniques in order to characterize the large extended basaltic areas in southern Syria. Four kinds of basalt have been identified: hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay, based on a statistical analysis approach with the threshold concept. The statistical conditions for such basalt characterization have been programmed in the present research to automatically interpret the well logging data for establishing and predicting the lithological cross-section of the studied well. A specific computer program has been written in Delphi for such purposes. The program is flexible and it can be used for other well logging applications by changing the statistical conditions and the well logging parameters. The program has been successfully tested on the Kodanah well logging data in southern Syria.

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

    Science.gov (United States)

    Asfahani, Jamal

    2011-03-01

    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.

  20. Expanding the Game Design Space

    DEFF Research Database (Denmark)

    Larsen, Lasse Juel; Majgaard, Gunver

    2016-01-01

    This article considers game design research in educational settings. Its focus is on how undergraduate students – particularly engineering students – learn computer game design. From observations conducted during our game design courses we have developed a model of expanded game design space....... It encapsulates the entire development process from the first ideas to the final game with emphasis on game design thinking. Our model of expanded game design space consists of four separate – yet interconnected – layers in the process of game development. The first layer addresses the importance of framing......, providing a clear game design assignment that involves the formulation of intended player experience and a description of game mechanics. The second layer focuses on game design thinking from six different aspects of game design chosen in relation to the framing of the game design assignment. The third...

  1. Pillow basalts of the Angayucham terrane: Oceanic plateau and island crust accreted to the Brooks Range

    Science.gov (United States)

    Pallister, John S.; Budahn, James R.; Murchey, Benita L.

    1989-11-01

    The Angayucham Mountains (north margin of the Yukon-Koyukuk province) are made up of an imbricate stack of four to eight east-west trending, steeply dipping, fault slabs composed of Paleozoic (Devonian to Mississippean), Middle to Late Triassic, and Early Jurassic oceanic upper crustal rocks (pillow basalt, subordinate diabase, basaltic tuff, and radiolarian chert). Field relations and geochemical characteristics of the basaltic rocks suggest that the fault slabs were derived from an oceanic plateau or island setting and were emplaced onto the Brooks Range continental margin. The basalts are variably metamorphosed to prehnite-pumpellyite and low-greenschist facies. Major element analyses suggest that many are hypersthene-normative olivine tholeiites. Classification based on immobile trace elements confirms the tholeiitic character of most of the basalts but suggests that some had primary compositions transitional to alkali basalt. Although field and petrographic features of the basalts are similar, trace element characteristics allow definition of geographically distinct suites. A central outcrop belt along the crest of the mountains is made up of basalt with relatively flat rare earth element (REE) patterns. This belt is flanked to the north and south by LREE (light rare earth element)-enriched basalts. Radiolarian and conodont ages from interpillow and interlayered chert and limestone indicate that the central belt of basalts is Triassic in age, the southern belt is Jurassic in age, and the northern belt contains a mixture of Paleozoic and Mesozoic ages. Data for most of the basalts cluster in the "within-plate basalt" fields of trace element discriminant diagrams; none have trace-element characteristics of island arc basalt. The Triassic and Jurassic basalts are geochemically most akin to modern oceanic plateau and island basalts. Field evidence also favors an oceanic plateau or island setting. The great composite thickness of pillow basalt probably resulted

  2. Lunar ferroan anorthosites and mare basalt sources - The mixed connection

    Science.gov (United States)

    Ryder, Graham

    1991-01-01

    Global overturn of a hot, gravitationally unstable lunar mantle immediately following the solidification of a magma ocean explains several characteristics of lunar petrology. Lunar mare basalt sources are inferred to be depleted in europium and alumina. These depletions are consensually attributed to complementary plagioclase floating from a magma ocean. However, in contrast to the mare basalt source parent magma, the ferroan anorthosite parent magma was more evolved by virtue of its lower Mg/Fe ratio and Ni abundances, although less evolved in its poverty of clinopyroxene constituents, flat rare earth pattern, and lower incompatible element abundances. The europium anomaly in mare sources is inferred to be present at 400 km depth, too deep to have been directly influenced by plagioclase crystallization. Massive overturning of the post-magma ocean mantle would have carried down clinopyroxene, ilmenite, and phases containing fractionated rare earths, europium anomalies, and some heat-producing radionuclides.

  3. Lunar ferroan anorthosites and mare basalt sources - The mixed connection

    Science.gov (United States)

    Ryder, Graham

    1991-11-01

    Global overturn of a hot, gravitationally unstable lunar mantle immediately following the solidification of a magma ocean explains several characteristics of lunar petrology. Lunar mare basalt sources are inferred to be depleted in europium and alumina. These depletions are consensually attributed to complementary plagioclase floating from a magma ocean. However, in contrast to the mare basalt source parent magma, the ferroan anorthosite parent magma was more evolved by virtue of its lower Mg/Fe ratio and Ni abundances, although less evolved in its poverty of clinopyroxene constituents, flat rare earth pattern, and lower incompatible element abundances. The europium anomaly in mare sources is inferred to be present at 400 km depth, too deep to have been directly influenced by plagioclase crystallization. Massive overturning of the post-magma ocean mantle would have carried down clinopyroxene, ilmenite, and phases containing fractionated rare earths, europium anomalies, and some heat-producing radionuclides.

  4. Diameter of basalt columns derived from fracture mechanics bifurcation analysis.

    Science.gov (United States)

    Bahr, H-A; Hofmann, M; Weiss, H-J; Bahr, U; Fischer, G; Balke, H

    2009-05-01

    The diameter of columnar joints forming in cooling basalt and drying starch increases with decreasing growth rate. This observation can be reproduced with a linear-elastic three-dimensional fracture mechanics bifurcation analysis, which has been done for a periodic array of hexagonal columnar joints by considering a bifurcation mode compatible with observations on drying starch. In order to be applicable to basalt columns, the analysis has been carried out with simplified stationary temperature fields. The critical diameter differs from the one derived with a two-dimensional model by a mere factor of 1/2. By taking into account the latent heat released at the solidification front, the results agree fairly well with observed column diameters.

  5. 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

  6. Radiolytic Hydrogen Production in the South Pacific Subseafloor Basaltic Aquifer

    Science.gov (United States)

    Dzaugis, M. E.; Spivack, A. J.; Dunlea, A. G.; Murray, R. W.; D'Hondt, S.

    2015-12-01

    Hydrogen (H2) is produced in geological settings by dissociation of water due to radiation from natural radioactive decay of 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 calculate radiolytic H2 production rates in basement fractures utilizing measured radionuclide concentrations in 42 basalt samples from IODP Expedition 329. The samples are from three sites with very different basement ages and a wide range of alteration types. Major and trace element concentrations vary by up to an order of magnitude from sample to sample. Comparison of our samples to each other and to previous studies of fresh East Pacific Rise basalt suggests that between-sample variation in radionuclide concentrations is primarily due to differences in initial (pre-alteration) concentrations (which can vary between eruptive events), rather than to alteration type or extent. Local maxima in radionuclide (U, Th, and K) concentrations produce 'hotspots' of radiolytic H2 production; calculated radiolytic rates differ by up to a factor of 80 from sample to sample. Fracture width also greatly influences H2 production. Due to the low penetration distance of alpha radiation, microfractures are 'hotpots' for radiolytic H2 production. For example, radiolytic H2 production rates normalized to water volume are 170 times higher in 1μm-wide fractures than in 10cm-wide fractures.

  7. 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.

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

    Science.gov (United States)

    Weisler, M I; Woodhead, J D

    1995-03-14

    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.

  9. Carbon dioxide sequestration in deep-sea basalt.

    Science.gov (United States)

    Goldberg, David S; Takahashi, Taro; Slagle, Angela L

    2008-07-22

    Developing a method for secure sequestration of anthropogenic carbon dioxide in geological formations is one of our most pressing global scientific problems. Injection into deep-sea basalt formations provides unique and significant advantages over other potential geological storage options, including (i) vast reservoir capacities sufficient to accommodate centuries-long U.S. production of fossil fuel CO2 at locations within pipeline distances to populated areas and CO2 sources along the U.S. west coast; (ii) sufficiently closed water-rock circulation pathways for the chemical reaction of CO2 with basalt to produce stable and nontoxic (Ca(2+), Mg(2+), Fe(2+))CO(3) infilling minerals, and (iii) significant risk reduction for post-injection leakage by geological, gravitational, and hydrate-trapping mechanisms. CO2 sequestration in established sediment-covered basalt aquifers on the Juan de Fuca plate offer promising locations to securely accommodate more than a century of future U.S. emissions, warranting energized scientific research, technological assessment, and economic evaluation to establish a viable pilot injection program in the future.

  10. Putative cryptoendolithic life in Devonian pillow basalt, Rheinisches Schiefergebirge, Germany.

    Science.gov (United States)

    Peckmann, J; Bach, W; Behrens, K; Reitner, J

    2008-03-01

    Middle Devonian (Givetian) pillow basalt and inter-pillow breccia from the Rheinisches Schiefergebirge in Germany were found to contain putative biogenic filaments that indicate that life once proliferated within these volcanic rocks. Mineralized filaments are found in carbonate amygdules (vesicles filled by carbonate cement) in the volcanic rock, where they started to form on the internal surface of the once water-filled vesicles. Biogenicity of the filaments is indicated by (1) their size and shape resembling modern microorganisms including a constant diameter along the length of curved filaments, (2) their independence of crystal faces or cleavage planes, (3) branching patterns reminiscent of modern microorganisms, and (4) their spatial clustering and preferential occurrence close to the margin of pillows and in the inter-pillow breccias. A time lag between the deposition of pillow basalt and the activity of endoliths is revealed by the sequence of carbonate cements filling the amygdules. The putative filamentous microorganisms thrived after the formation of early fibrous rim cement, but before later equant calcite spar filled most of the remaining porosity. Microbial clay authigenesis analogous to the encrustation of prokaryotes in modern iron-rich environments led to the preservation of filaments. The filaments predominantly consist of the clay minerals chamosite and illite. Having dwelled in water-filled vesicles, the Devonian basalt-hosted filaments apparently represent cryptoendoliths. This finding suggests that a previously unrecognized niche for life exists within volcanic rock.

  11. 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.

  12. Assessing eruption column height in ancient flood basalt eruptions

    Science.gov (United States)

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

    2017-01-01

    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 ∼ 45 ° N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the ∼ 180km of known Roza fissure length could have supported ∼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 (∼ 66Ma) 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 flood basalt eruptions could have influenced

  13. 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

  14. Differentiation mechanism of frontal-arc basalt magmas

    Science.gov (United States)

    Kuritani, T.; Yoshida, T.; Kimura, J.; Hirahara, Y.; Takahashi, T.

    2012-04-01

    In a cooling magma chamber, magmatic differentiation can proceed both by fractionation of crystals from the main molten part of the magma body (homogeneous fractionation) and by mixing of the main magma with fractionated melt derived from low-temperature mush zones (boundary layer fractionation) (Jaupart and Tait, 1995, and references therein). The geochemical path caused by boundary layer fractionation can be fairly different from a path resulting from homogeneous fractionation (e.g., Langmuir, 1989). Therefore, it is important to understand the relative contributions of these fractionation mechanisms in magma chambers. Kuritani (2009) examined the relative roles of the two fractionation mechanisms in cooling basaltic magma chambers using a thermodynamics-based mass balance model. However, the basaltic magmas examined in the work were alkali-rich (Na2O+K2O > 4 wt.%). In this study, to explore differentiation mechanisms of frontal-arc basalt magmas that are volumetrically much more important than rear-arc alkali basalt magmas, the relative roles of the two fractionation mechanisms are examined for low-K tholetiitic basalt magma from Iwate Volcano, NE Japan arc, using the same mass balance model. First, the water content and the temperature of the Iwate magma were estimated. The Iwate lavas are moderately porphyritic, consisting of ~8 vol.% olivine and ~20 vol.% plagioclase phenocrysts. The olivine and plagioclase phenocrysts show significant compositional variations, and the Mg# of olivine phenocrysts (Mg#78-81) correlates positively with the An content of coexisting plagioclase phenocrysts (An85-92). The olivine phenocrysts with Mg# > ~82 do not form crystal aggregates with plagioclase. It is inferred from these observations that the phenocrysts with variable compositions were derived from a common magma with variable temperature in a magma chamber, and the plagioclase phenocrysts were all derived from mushy boundary layers along the walls of the magma chamber. By

  15. 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].

  16. 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.

  17. Preliminary Study on the PGE Geochemistry of the Permian Basalts in the Jinping Area

    Institute of Scientific and Technical Information of China (English)

    Nian Hong; Shen Wei; Zhang Xueshu

    2006-01-01

    To disclose and study the magma genesis of the Permian basalts in the Jinping (金平)area, the PGE and Au contents of the Permian basalts in the Jinping area were assayed by use of the ICP-MS method. The PGE data show relatively strong differentiation of basaltic magma in comparison with the primitive mantle. The primitive mantle-normalized pattern is a left-dipping curve of the Pd-Pt enriched type. The Pd/Ir ratios of the PGE of the Permian basalts in the Jinping area are higher than those of the primitive mantle and the upper primitive mantle and the chondrite meteorite. The Pd/Ir ramaterial source. It is concluded that they are derived from the basaltic magma of the upper mantle source with a lower melting degree, which shares the similar magma material source with the Emeishan Permian basalts as a whole.

  18. Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt.

    Science.gov (United States)

    Dixon, Jacqueline Eaby; Leist, Loretta; Langmuir, Charles; Schilling, Jean-Guy

    2002-11-28

    A substantial uncertainty in the Earth's global geochemical water cycle is the amount of water that enters the deep mantle through the subduction and recycling of hydrated oceanic lithosphere. Here we address the question of recycling of water into the deep mantle by characterizing the volatile contents of different mantle components as sampled by ocean island basalts and mid-ocean-ridge basalts. Although all mantle plume (ocean island) basalts seem to contain more water than mid-ocean-ridge basalts, we demonstrate that basalts associated with mantle plume components containing subducted lithosphere--'enriched-mantle' or 'EM-type' basalts--contain less water than those associated with a common mantle source. We interpret this depletion as indicating that water is extracted from the lithosphere during the subduction process, with greater than 92 per cent efficiency.

  19. Black holes in an expanding universe.

    Science.gov (United States)

    Gibbons, Gary W; Maeda, Kei-ichi

    2010-04-02

    An exact solution representing black holes in an expanding universe is found. The black holes are maximally charged and the universe is expanding with arbitrary equation of state (P = w rho with -1 black hole temperature.

  20. Collapsible truss structure is automatically expandable

    Science.gov (United States)

    1965-01-01

    Coil springs wound with maximum initial tension in a three-truss, closed loop structure form a collapsible truss structure. The truss automatically expands and provides excellent rigidity and close dimensional tolerance when expanded.

  1. 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.

  2. 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...

  3. 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.

  4. Diffusive fractionation of trace elements in basaltic melt

    Science.gov (United States)

    Holycross, Megan E.; Bruce Watson, E.

    2016-10-01

    The chemical diffusivities of 25 trace elements (Sc, V, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Hf, Ta, Th, and U) in basaltic melt were measured in diffusion couple experiments performed at 1 GPa pressure and temperatures from 1250 to 1500 °C. Trace element concentration gradients developed in the glasses were simultaneously characterized using laser ablation ICP/MS to create an internally consistent data set. A ratio-fitting technique was employed to accurately determine the relative diffusivities of the rare earth elements (REE). All diffusion coefficients conform to the expected Arrhenius relation D = D 0exp(- E a /RT), where the constant log( D 0, m2/s) ranges from -3.81 to -5.11 and E a ranges from 161.73 to 223.81 kJ/mol. The slowest diffusivities are obtained for the high-field-strength elements; the fastest diffusivities are obtained for the low-field-strength elements. Trace element diffusion in MORB follows the compensation law, where log D 0 is linearly correlated with E a. Arrhenius parameters for diffusion of trivalent REE monotonically increase from La to Lu and are near-linear functions of bond strength (the variation in Arrhenius parameters means that the diffusivities decrease monotonically from La to Lu at a given T). The new data for trace element diffusion in basaltic melt can be used to explore the potential for diffusive fractionation of trace elements using kinetic models. Concentrations of the slower-diffusing heavy REE may be altered relative to those of the faster-diffusing light REE as a diffusive boundary layer develops in melt-melt and crystal-melt systems. The results indicate that diffusion in basalt can be an effective mechanism to fractionate trace elements from one another.

  5. 3D Finite Difference Modelling of Basaltic Region

    Science.gov (United States)

    Engell-Sørensen, L.

    2003-04-01

    The main purpose of the work was to generate realistic data to be applied for testing of processing and migration tools for basaltic regions. The project is based on the three - dimensional finite difference code (FD), TIGER, made by Sintef. The FD code was optimized (parallelized) by the author, to run on parallel computers. The parallel code enables us to model large-scale realistic geological models and to apply traditional seismic and micro seismic sources. The parallel code uses multiple processors in order to manipulate subsets of large amounts of data simultaneously. The general anisotropic code uses 21 elastic coefficients. Eight independent coefficients are needed as input parameters for the general TI medium. In the FD code, the elastic wave field computation is implemented by a higher order FD solution to the elastic wave equation and the wave fields are computed on a staggered grid, shifted half a node in one or two directions. The geological model is a gridded basalt model, which covers from 24 km to 37 km of a real shot line in horizontal direction and from the water surface to the depth of 3.5 km. The 2frac {1}{2}D model has been constructed using the compound modeling software from Norsk Hydro. The vertical parameter distribution is obtained from observations in two wells. At The depth of between 1100 m to 1500 m, a basalt horizon covers the whole sub surface layers. We have shown that it is possible to simulate a line survey in realistic (3D) geological models in reasonable time by using high performance computers. The author would like to thank Norsk Hydro, Statoil, GEUS, and SINTEF for very helpful discussions and Parallab for being helpful with the new IBM, p690 Regatta system.

  6. Shear Acceleration in Expanding Flows

    CERN Document Server

    Rieger, F M

    2016-01-01

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets of active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi-Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplify that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge ...

  7. OCT Expanded Clinical Data Analysis

    Science.gov (United States)

    Van Baalen, Mary; Tafreshi, Ali; Patel, Nimesh; Young, Millennia; Mason, Sara; Otto, Christian; Samuels, Brian; Koslovsky, Matthew; Schaefer, Caroline; Taiym, Wafa; Wear, Mary; Gibson, Charles; Tarver, William

    2017-01-01

    Vision changes identified in long duration space fliers has led to a more comprehensive clinical monitoring protocol. Optical Coherence Tomography (OCT) was recently implemented on board the International Space Station in 2013. NASA is collaborating with Heidelberg Engineering to expand our current OCT data analysis capability by implementing a volumetric approach. Volumetric maps will be created by combining the circle scan, the disc block scan, and the radial scan. This assessment may provide additional information about the optic nerve and further characterize changes related microgravity exposure. We will discuss challenges with collection and analysis of OCT data, present the results of this reanalysis and outline the potential benefits and limitations of the additional data.

  8. Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Mengal Ali Nawaz

    2014-07-01

    Full Text Available In this study, Basalt fiber reinforced plastic (BFRP wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP. Finite element analysis (FEA of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength compared to GFRP wind turbine blade.

  9. 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.

  10. 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.

  11. Geochemical characterization of tubular alteration features in subseafloor basalt glass

    Science.gov (United States)

    Knowles, Emily; Staudigel, Hubert; Templeton, Alexis

    2013-07-01

    There are numerous indications that subseafloor basalts may currently host a huge quantity of active microbial cells and contain biosignatures of ancient life in the form of physical and chemical basalt glass alteration. Unfortunately, technological challenges prevent us from observing the formation and mineralization of these alteration features in situ, or reproducing tubular basalt alteration processes in the laboratory. Therefore, comprehensive analysis of the physical and chemical traces retained in mineralized tubules is currently the best approach for deciphering a record of glass alteration. We have used a number of high-resolution spectroscopic and microscopic methods to probe the geochemical and mineralogical characteristics of tubular alteration features in basalt glasses obtained from a suite of subseafloor drill cores that covers a range of different collection locations and ages. By combining three different synchrotron-based X-ray measurements - X-ray fluorescence microprobe mapping, XANES spectroscopy, and μ-XRD - with focused ion beam milling and transmission electron microscopy, we have spatially resolved the major and trace element distributions, as well as the oxidation state of Fe, determined the coordination chemistry of Fe, Mn and Ti at the micron-scale, and constrained the secondary minerals within these features. The tubular alteration features are characterized by strong losses of Fe2+, Mn2+, and Ca2+ compared to fresh glass, oxidation of the residual Fe, and the accumulation of Ti and Cu. The predominant phases infilling the alteration regions are Fe3+-bearing silicates dominated by 2:1 clays, with secondary Fe- and Ti-oxides, and a partially oxidized Mn-silicate phase. These geochemical patterns observed within the tubular alteration features are comparable across a diverse suite of samples formed over the past 5-100 Ma, which shows that the microscale mineralization processes are common and consistent throughout the ocean basins and

  12. Explosive deep water basalt in the sumisu backarc rift.

    Science.gov (United States)

    Gill, J; Torssander, P; Lapierre, H; Taylor, R; Kaiho, K; Koyama, M; Kusakabe, M; Aitchison, J; Cisowski, S; Dadey, K; Fujioka, K; Klaus, A; Lovell, M; Marsaglia, K; Pezard, P; Taylor, B; Tazaki, K

    1990-06-08

    Eruption of 1-million-year-old tholeiitic basalt >1800 meters below sea level (>18 megapascals) in a backarc rift behind the Bonin arc produced a scoriaceous breccia similar in some respects to that formed during subaerial eruptions. Explosion of the magma is thought to have produced frothy agglutinate which welded either on the sea floor or in a submarine eruption column. The resulting 135-meter-thick pyroclastic deposit has paleomagnetic inclinations that are random at a scale of <2.5 meters. High magmatic water content, which is about 1.3 percent by weight after vesiculation, contributed to the explosivity.

  13. A Study on the Forming Conditions of Basalts in Seamounts of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    李兆麟; 梁德华; 等

    1994-01-01

    Volcanic rocks in seamounts of the South China Sea consist mainly of alkali basalt, tholeiitic basalt, trachyandesitic pumice, dacite, etc.Inclusions in the minerals of the volcanic rocks are main-ly amorphors melt inclusions, which reflects that the volcanic rocks are characterized by submarine eruption and rapid cooling on the seafloor .Furthermore, fluid-melt inclusions have been discovered for the first time in alkali basalts and mantle-derived xenoliths,indicating a process of differentiation between magma and fluid in the course of mantle partial melting .Alkali basalts and inclusions may have been formed in this nonhomogeneous system.Rock-forming temperatures of four seamouns estimated as follows:the Z hongnan seamount alkali basalt 1155-1185℃; the Xianbei seamount alkali basalt 960-1200℃; tholeiitic basalt 1040-1230℃; the Daimao seamount tholeiitic basalt 1245-1280℃; and the Jianfeng seamount trachandestic prmice 880-1140℃. Equilibrium pressures of alkali basalts in the Zhongnan and Xianbei seamounts are 13.57 and 8.8×108 Pa ,respectively. Pyroxene equilibrium tem-peratures of mantle xenoliths from the Xianbei seamount were estimated at 1073-1121℃, and pres-sures ar (15.58-22.47)×108Pa, suggesting a deep-source (e.g.the asthenosphere )for the alkalibasalts.

  14. A new source of basaltic meteorites inferred from Northwest Africa 011.

    Science.gov (United States)

    Yamaguchi, Akira; Clayton, Robert N; Mayeda, Toshiko K; Ebihara, Mitsuru; Oura, Yasuji; Miura, Yayoi N; Haramura, Hiroshi; Misawa, Keiji; Kojima, Hideyasu; Nagao, Keisuke

    2002-04-12

    Eucrites are a class of basaltic meteorites that share common mineralogical, isotopic, and chemical properties and are thought to have been derived from the same parent body, possibly asteroid 4 Vesta. The texture, mineralogy, and noble gas data of the recently recovered meteorite, Northwest Africa (NWA) 011, are similar to those of basaltic eucrites. However, the oxygen isotopic composition of NWA011 is different from that of other eucrites, indicating that NWA011 may be derived from a different parent body. The presence of basaltic meteorites with variable oxygen isotopic composition suggests the occurrence of multiple basaltic meteorite parent bodies, perhaps similar to 4 Vesta, in the early solar system.

  15. Derivation of Apollo 14 High-Al Basalts at Discrete Times: Rb-Sr Isotopic Constraints

    Science.gov (United States)

    Hui. Hejiu; Neal, Clive, R.; Shih, Chi-Yu; Nyquist, Laurence E.

    2012-01-01

    Pristine Apollo 14 (A-14) high-Al basalts represent the oldest volcanic deposits returned from the Moon [1,2] and are relatively enriched in Al2O3 (>11 wt%) compared to other mare basalts (7-11 wt%). Literature Rb-Sr isotopic data suggest there are at least three different eruption episodes for the A-14 high-Al basalts spanning the age range approx.4.3 Ga to approx.3.95 Ga [1,3]. Therefore, the high-Al basalts may record lunar mantle evolution between the formation of lunar crust (approx.4.4 Ga) and the main basin-filling mare volcanism (basalts were originally classified into five compositional groups [5,6], and then regrouped into three with a possible fourth comprising 14072 based on the whole-rock incompatible trace element (ITE) ratios and Rb-Sr radiometric ages [7]. However, Rb-Sr ages of these basalts from different laboratories may not be consistent with each other because of the use of different 87Rb decay constants [8] and different isochron derivation methods over the last four decades. This study involved a literature search for Rb-Sr isotopic data previously reported for the high-Al basalts. With the re-calculated Rb-Sr radiometric ages, eruption episodes of A-14 high-Al basalts were determined, and their petrogenesis was investigated in light of the "new" Rb-Sr isotopic data and published trace element abundances of these basalts.

  16. Trace Element Geochemistry of Hannuoba Ultramafic Inclusion—bearing Alkali Basalts

    Institute of Scientific and Technical Information of China (English)

    支霞臣

    1990-01-01

    Presented in this paper are the trace element abundances of 16 samples of Hannuoba ultramafic inclusion-bearing aldali basalts,which were determined by instrumental neutron activation analysis and X-ray fluorescence spectrometry.The Petrogenesis of the alkali basalt suite has been modeled by batch partial melting and and Rayleigh fractional crystallization processes,The geochemical characteristics of the mantle source from where alkali basalts were derived are described in terms of variations in trace element abundances of the alkali basalt suite.

  17. Radiation shielding properties of a novel cement–basalt mixture for nuclear energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Ipbüker, Cagatay; Nulk, Helena; Gulik, Volodymyr [University of Tartu, Institute of Physics (Estonia); Biland, Alex [HHK Technologies, Houston (United States); Tkaczyk, Alan Henry, E-mail: alan@ut.ee [University of Tartu, Institute of Physics (Estonia)

    2015-04-01

    Highlights: • Basalt fiber is a relatively cheap material that can be used as reinforcement. • Gamma-ray attenuation remains relatively stable with addition of basalt fiber. • Neutron attenuation remains relatively stable with addition of basalt fiber. • Cement–basalt mixture has a good potential for use in nuclear energy applications. - Abstract: The radiation shielding properties of a new proposed building material, a novel cement–basalt fiber mixture (CBM), are investigated. The authors analyze the possibility of this material to be a viable substitute to outgoing materials in nuclear energy applications, which will lead to a further sustained development of nuclear energy in the future. This computational study involves four types of concrete with various amounts of basalt fiber in them. The gamma-ray shielding characteristics of proposed CBM material are investigated with the help of WinXCom program, whereas the neutron shielding characteristics are computed by the Serpent code. For gamma-ray shielding, we find that the attenuation coefficients of concretes with basalt fibers are not notably influenced by the addition of fibers. For neutron shielding, additional basalt fiber in mixture presents negligible effect on neutron radiation shielding. With respect to radiation shielding, it can be concluded that basalt fibers have good potential as an addition to heavyweight concrete for nuclear energy applications.

  18. Flood basalt hosted palaeosols:Potential palaeoclimatic indicators of global climate change

    Institute of Scientific and Technical Information of China (English)

    M.R.G. Sayyed

    2014-01-01

    Since continental sediments (in addition to the marine geological record) offer important means of deciphering environmental changes, the sediments hosted by the successive flows of the continental flood basalt provinces of the world should be treasure houses in gathering the palaeoclimatic data. Palaeosols developed on top of basalt flows are potentially ideal for palaeoenvironmental reconstructions because it is easy to determine their protolith geochemistry and also they define a definite time interval. The present paper summarizes the nature of the basalt-hosted palaeosols formed on the flood basalts provinces from different parts of the globe having different ages.

  19. Geology of the Sabie River Basalt Formation in the Southern Kruger National Park

    Directory of Open Access Journals (Sweden)

    R.J. Sweeney

    1986-12-01

    Full Text Available The Sabie River Basalt Formation (SRBF in the central Lebombo is a virtually continuous sequence of basaltic lavas some 2 500 m thick that was erupted 200 - 179 Ma ago. Flows are dominantly pahoehoe in character and vary from 2 m to 20 m in thickness. Dolerite dykes cross-cutting the basalt sequence probably represent feeders to this considerable volcanic event. Volcanological features observed within the SRBF are described. Two chemically distinct basaltic magma types are recognised, the simultaneous eruption of which presents an intriguing geochemical problem as to their origins.

  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. 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.

  2. 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.

  3. 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 frictio......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...... image correlation for displacement monitoring. Pullout results and validation tests are presented. In the discussion, the results and the importance of the grips surface finish with regard to pullout force are discussed. The discussion was backed by investigations on wear patterns using SEM....

  4. Magnetic ores with steel or basalt for concrete radiation shielding

    Energy Technology Data Exchange (ETDEWEB)

    Bashter, I.I. [Zagazig Univ. (Egypt). Faculty of Science; A. El-Sayed, Abdo; M. Samir, Abdel-Azim

    1997-06-01

    This paper is concerned with the study of the leakage spectra of total gamma rays and fast neutrons from two types of heavy concretes made from local magnetite ores. The two types are the steel-magnetite concrete ({rho}=5.11 g/cm{sup 3}) and the basalt-magnetite concrete ({rho}=3.05 g/cm{sup 3}). The radiation source used was a collimated beam emitted from one of the horizontal channels of the ET-RR-1 reactor. Total gamma rays and fast neutrons were measured using a gamma-neutron spectrometer with a stilbene scintillator. Gamma ray or neutron events were rejected by a pulse shape discriminator based on the zero cross over method. The obtained data were displayed in the form of spatial fluxes and energy distributions and attenuation curves. The linear attenuation coefficients for total gamma rays, macroscopic removal cross sections for fast neutrons and half-value layers for gamma rays and neutrons have been obtained for the whole energy range and at different energies. Comparison with other published data has been done when such data are available. For comparison, the steel-magnetite concrete is a much better radiation attenuator than the magnetite and basalt-magnetite concretes, especially for thick shields. (author)

  5. Lead isotopes and the sources of the Columbia River Basalt Group

    Science.gov (United States)

    Chamberlain, V. E.; Lambert, R. St. J.

    1994-06-01

    A detailed study of Pb-208/Pb-204, Pb-207/Pb-204, and Pb-206/Pb-204 ratios suggests that the number of Pb isotopic reservoirs required for the Columbia River Basalt Group (CRBG) (as currently defined) must be increased from the presently accepted four to at least six. The identities of the six reservoirs are two of mid-ocean ridge basalt (MORB) slightly contaminated with sediment (R1 and R2, R1 being 'Cascades' PB); one a probable plume component (R3); two of unspecified mantle material but probably of R1 type, contaminated with local crustal Pb (R4 and R5); and the sixth a complex enriched reservoir of 2150 Ma age (R6). R1 is an end-member for all CRBG, except the Saddle Mountains Basalts. R2 is a second end-member for the Picture Gorge Basalt and CRBG, except the Saddle Mountains Basalts. R2 is a second end-member for the Picture Gorge Basalt and appears to be unique to it. R3 is the principal source for most of the Wanapum Basalt, as well as for most of the chemically evolved portions of the Grande Ronde Basalt. Volumetric and tectonic considerations require that one source of the CRBG be a plume or, at least, a nonlocal crustal or uppermost mantle source, and R3 is the ideal candidate for that role. R4 is the second source for the Imnaha Basalt, and R5 is the source for the (206)Pb-rich varieties of the Grande Ronde Basalt. R4 and R5 are identified with contamination by local Phanerozoic crust because of their similarity to local crustal Pb and because the rocks which contain them also have Cu contents correlated with their Pb isotopic compositions. R6 is the parent for Pb in all the Saddle Mountain Basalts. This last source appears to have been homogeneous 2150 m.y. ago but has since split into a number of separate, discrete pockets, each with its own characteristic Pb isotopic signature. Some of these appear in individual Saddle Mountain Basalt flows, while other sources have mixed with R4 to produce individual Saddle Mountain Basalt flows of the Ice Harbor

  6. Discovery of Uniformly Expanding Universe

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2012-01-01

    Full Text Available Saul Perlmutter and the Brian Schmidt – Adam Riess teams reported that their Friedmann-model GR-based analysis of their supernovae magnitude-redshift data re- vealed a new phenomenon of “dark energy” which, it is claimed, forms 73% of the energy / matter density of the present-epoch universe, and which is linked to the further claim of an accelerating expansion of the universe. In 2011 Perlmutter, Schmidt and Riess received the Nobel Prize in Physics “for the discovery of the accelerating ex- pansion of the Universe through observations of distant supernovae”. Here it is shown that (i a generic model-independent analysis of this data reveals a uniformly expanding universe, (ii their analysis actually used Newtonian gravity, and finally (iii the data, as well as the CMB fluctuation data, does not require “dark energy” nor “dark matter”, but instead reveals the phenomenon of a dynamical space, which is absent from the Friedmann model.

  7. Cat Scratch Disease: Expanded Spectrum

    Science.gov (United States)

    Aziz, Hassan A.; Plesec, Thomas P.; Sabella, Camille; Udayasankar, Unni K.; Singh, Arun D.

    2016-01-01

    Background To expand the spectrum of ophthalmic manifestations in cat scratch disease. Methods Case report. Results A 7-year-old male was referred for evaluation of his left optic disc after failing vision screening test at school. His visual acuity was 20/20 OD and light perception OS. Fundus examination showed a left optic disc lesion associated with an exudative retinal detachment and vitreous seeding. Ultrasonography revealed a 7 × 7.5 × 3.8 mm lesion with a possible 6.3 mm of retrolaminar extension into the substance of the optic nerve. Brain MRI did not show evidence of optic nerve involvement but revealed a 6-mm nodule of the pineal gland suggestive of a pineoblastoma. Enucleation was performed and histopathology revealed a suppurative granulomatous inflammation suggestive of Bartonella infection. Upon further questioning, the patient had recent exposure to kittens with areas of cat scratches along both of his arms. He was subsequently referred to and treated with a 2-week course of trimethoprim-sulfamethoxazole and rifampin by the pediatric infectious disease specialist. Repeat brain MRI showed interval total resolution of enlarged pineal gland. Conclusion: Optic nerve granulomas are a rare presentation of cat scratch disease and could potentially masquerade as retinoblastoma. PMID:27843905

  8. Expanding mTOR signaling

    Institute of Scientific and Technical Information of China (English)

    Qian Yang; Kun-Liang Guan

    2007-01-01

    The mammalian target of rapamycin (mTOR) has drawn much attention recently because of its essential role in cell growth control and its involvement in human tumorigenesis. Great endeavors have been made to elucidate the functions and regulation of mTOR in the past decade. The current prevailing view is that mTOR regulates many fundamental biological processes, such as cell growth and survival, by integrating both intracellular and extracellular signals, including growth factors, nutrients, energy levels, and cellular stress. The significance of mTOR has been highlighted most recently by the identification of mTOR-associated proteins. Amazingly, when bound to different proteins, mTOR forms distinctive complexes with very different physiological functions. These findings not only expand the roles that mTOR plays in cells but also further complicate the regulation network. Thus, it is now even more critical that we precisely understand the underlying molecular mechanisms in order to directly guide the development and usage of anti-cancer drugs targeting the mTOR signaling pathway. In this review, we will discuss different mTOR-associated proteins, the regulation of mTOR complexes, and the consequences of mTOR dysregulation under pathophysiological conditions.

  9. A depleted, not ideally chondritic bulk Earth: The explosive-volcanic basalt loss hypothesis

    Science.gov (United States)

    Warren, Paul H.

    2008-04-01

    It has long been customary to assume that in the bulk composition of the Earth, all refractory-lithophile elements (including major oxides Al 2O 3 and CaO, all of the REE, and the heat-producing elements Th and U) occur in chondritic, bulk solar system, proportion to one another. Recently, however, Nd-isotopic studies (most notably Boyet M. and Carlson R. W. (2006) A new geochemical model for the Earth's mantle inferred from 146Sm- 142Nd systematics. Earth Planet. Sci. Lett.250, 254-268) have suggested that at least the outer portion of the planet features a Nd/Sm ratio depleted to ˜0.93 times the chondritic ratio. The primary reaction to this type of evidence has been to invoke a "hidden" reservoir of enriched matter, sequestered into the deepest mantle as a consequence of primordial differentiation. I propose a hypothesis that potentially explains the evidence for Nd/Sm depletion in a very different way. Among the handful of major types of differentiated asteroidal meteorites, two (ureilites and aubrites) are ultramafic restites so consistently devoid of plagioclase that meteoriticists were once mystified as to how all the complementary plagioclase-rich matter (basalt) was lost. The explanation appears to be basalt loss by graphite-fueled explosive volcanism on roughly 100-km sized planetesimals; with the dispersiveness of the process dramatically enhanced, relative to terrestrial experience, because the pyroclastic gases expand into vacuous space (Wilson L. and Keil K. (1991) Consequences of explosive eruptions on small Solar System bodies: the case of the missing basalts on the aubrite parent body. Earth Planet. Sci. Lett.104, 505-512). By analogy with lunar pyroclastic products, the typical size of pyroclastic melt/glass droplets under these circumstances will be roughly 0.1 mm. Once separated from an asteroidal or planetesimal gravitational field, droplets of this size will generally spiral toward the Sun, rather than reaccrete, because drag forces such the

  10. Zeolites in Eocene basaltic pillow lavas of the Siletz River Volcanics, Central Coast Range, Oregon.

    Science.gov (United States)

    Keith, T.E.C.; Staples, L.W.

    1985-01-01

    Zeolites and associated minerals occur in a tholeiitic basaltic pillow lava sequence. Although the zeolite assemblages are similar to those found in other major zeolite occurrences in basaltic pillow lavas, regional zoning of the zeolite assemblages is not apparent. The formation of the different assemblages is discussed.-D.F.B.

  11. Basalt Waste Isolation Project. Quarterly report, July 1, 1980-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.

    1980-11-01

    This report presents the technical progress for the Basalt Waste Isolation Project for the fourth quarter of fiscal year 1980. The overall Basalt Waste Isolation Project is divided into the following principal work areas: systems integration; geosciences; hydrology; engineered barriers; near-surface test facility; engineering testing; and repository studies. Summaries of major accomplishments for each of these areas are reported.

  12. 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...

  13. Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

    1980-05-23

    This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive.

  14. Signatures of the source for the Emeishan flood basalts in the Ertan area: Pb isotope evidence

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Emeishan flood basalts can be divided into high-Ti (HT) basalt (Ti/Y>500) and low-Ti (LT) basalt (Ti/Y<500). Sr, Nd isotopic characteristics of the lavas indicate that the LT- and the HT-type magmas originated from distinct mantle sources and parental magmas. The LT-type magma was derived from a shallower lithospheric mantle, whereas the HT-type magma was derived from a deeper mantle source that may be possibly a mantle plume. However, few studies on the Emeishan flood basalts involved their Pb isotopes, especially the Ertan basalts. In this paper, the authors investigated basalt samples from the Ertan area in terms of Pb isotopes, in order to constrain the source of the Emeishan flood basalts. The ratios of 206Pb/204Pb (18.31-18.41), 207Pb/204Pb (15.55-15.56) and 208Pb/204Pb (38.81-38.94) are significantly higher than those of the depleted mantle, just lying between EM I and EM II. This indicates that the Emeishan HT basalts (in the Ertan area) are the result of mixing of EMI end-member and EMII end-member.

  15. Geochemical constraints on the petrogenesis of basalts from eastern Jiangnan orogen, South China

    Institute of Scientific and Technical Information of China (English)

    唐红峰; 周新民

    1997-01-01

    The basalts crop out widely in the eastern part of late Proterozoic Jiangnan orogen. In terms of their petrographical and geochemical characteristics, they can be divided into two distinct types: low- and high-Ti basalts. They crystallized from the magmas derived from the depleted upper mantle differing in partial melting degree.

  16. Transition from platemargin to intraplate environment: Geochemistry of basalts in Paleogene Liaohe basin, northeastern China

    Institute of Scientific and Technical Information of China (English)

    WU Changzhi; GU Lianxing; REN Zuowei; ZHANG Zunzhong; CHEN Zhenyan; ZHAO Ming

    2005-01-01

    Paleogene basalts from the Liaohe basin, northeastern China, are dominated by alkaline olivine basalts and olivine basalts. These basalts are generally enriched in high field strength elements (HFSE), depleted in large ion lithophile elements (LILE) and comparable to those of typical ocean island basalts (OIB). Positive anomalies of Ba, Sr and Zr with high Nb/U, U/Pb, Ce/Pb and Zr/Hf ratios imply that materials from an oceanic crust had been added to the mantle sources of the basalts. In addition, the basalts are generally depleted in Sr, Nd and Pb isotopes, indicating that an enriched mantle (EMI) and a depleted mantle (DM) sources were added to the OIB-like resource.Comprehensive research on lithosphere evolution and tectonic setting of the Liaohe basin and surrounding areas suggests that these basalts were derived by variable degrees of partial melting from an upwelling asthenosphere mantle. Materials from an oceanic lithosphere were added to the source in company with Paleogene tectonic transition from platemargin to intraplate environment. Retreating and steepening of the subducting Pacific oceanic plate could be the main cause for the tectonic environment transition.

  17. Spectral evidence for weathered basalt as an alternative to andesite in the northern lowlands of Mars.

    Science.gov (United States)

    Wyatt, Michael B; McSween, Harry Y

    2002-05-16

    Mineral abundances derived from the analysis of remotely sensed thermal emission data from Mars have been interpreted to indicate that the surface is composed of basalt (Surface Type 1) and andesite (Surface Type 2). The global distribution of these rock types is divided roughly along the planetary dichotomy which separates ancient, heavily cratered crust in the southern hemisphere (basalt) from younger lowland plains in the north (andesite). But the existence of such a large volume of andesite is difficult to reconcile with our present understanding of the geological evolution of Mars. Here we reinterpret martian surface rock lithologies using mineral abundances from previous work and new mineralogies derived from a spectral end-member set representing minerals common in unaltered and low-temperature aqueously altered basalts. Our results continue to indicate the dominance of unaltered basalt in the southern highlands, but reveal that the northern lowlands can be interpreted as weathered basalt as an alternative to andesite. The coincidence between locations of such altered basalt and a suggested northern ocean basin implies that lowland plains material may be composed of basalts weathered under submarine conditions or weathered basaltic sediments transported into this depocentre.

  18. 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...

  19. Searching for neuKREEP: An EMP study of Apollo 11 Group A basalts

    Science.gov (United States)

    Jerde, Eric A.; Taylor, Lawrence A.

    1993-01-01

    The Apollo 11 and 17 landing sites are characterized by the presence of high-Ti basalts (TiO2 greater than 6 percent). The Group A basalts of Apollo 11 have elevated K compositions (greater than 2000 ppm); and are enriched in incompatible trace elements relative to the other types of high-Ti basalt found in the region. These unique basalts also are the youngest of all high-Ti basalts, with an age of 3.56 +/- 0.02 Ga. Recent modelling of the Apollo 11 Group A basalts by Jerde et al. has demonstrated that this unique variety of high-Ti basalt may have formed through fractionation of a liquid with the composition of the Apollo 11 orange glass, coupled with assimilation of evolved material (dubbed neuKREEP and having similarities to lunar quartz monzodiorite). Assimilation of this material would impart its REE signature on the liquid, resulting in the elevated REE abundances observed. Minerals such as whitlockite which contain a large portion of the REE budget can be expected to reflect the REE characteristics of the assimilant. To this end, an examination of the whitlockite present in the Apollo 11 Group A basalts was undertaken to search for evidence of the neuKREEP material assimilated.

  20. Origin of quaternary basalts from the Black Rock Desert Region, Utah.

    Science.gov (United States)

    Condie, K. C.; Barsky, C. K.

    1972-01-01

    An evaluation has been made of the relative roles of fractional crystallization and crustal contamination in the genesis of basaltic magmas from the Black Rock Desert region in Utah. As a result, geochemical variations of these basalts have been defined as a function of their ages of eruption.

  1. 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.

  2. Constitutive equations of basalt filament tows under quasi-static and high strain rate tension

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Lvtao; Sun Baozhong [College of Textiles, Donghua University, Shanghai 201620 (China); Hu, Hong [Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom Kowloon (Hong Kong); Gu Bohong, E-mail: gubh@dhu.edu.cn [College of Textiles, Donghua University, Shanghai 201620 (China); Department of Textile Engineering, Zhongyuan Institute of Technology, Zhengzhou, Henan Province 450007 (China)

    2010-05-25

    The tensile properties of basalt filament tows were tested at quasi-static (0.001 s{sup -1}) and high strain rates (up to 3000 s{sup -1}) with MTS materials tester (MTS 810.23) and split Hopkinson tension bar (SHTB), respectively. Experimental results showed that the mechanical properties of the basalt filament tows were rather sensitive to strain rate. Specifically, the stiffness and failure stress of the basalt filament tows increased distinctly as the strain rate increased, while the failure strain decreased. From scanning electronic microscope (SEM) photographs of the fracture surface, it is indicated that the basalt filament tows failed in a more brittle mode and the fracture surface got more regular as the strain rate increases. The strength distributions of the basalt filament tows have been evaluated by a single Weibull distribution function. The curve predicted from the single Weibull distribution function was in good agreement with the experimental data points.

  3. /sup 87/Sr//sup 86/Sr ratios for basalt from Loihi Seamount, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Lanphere, M. (Geological Survey, Menlo Park, CA (USA))

    1983-12-01

    /sup 87/Sr//sup 86/Sr ratios of 15 samples of basalt dredged from Loihi Seamount range from 0.70334 to 0.70368. The basalt types range from tholeiite to basanite in composition and can be divided into six groups on the basis of abundances of K/sub 2/O, Na/sub 2/O, Rb and Sr and /sup 87/Sr//sup 86/Sr ratio. The isotopic data require that the various basalt types be derived from source regions differing in Sr isotopic composition. The Loihi basalts may be produced by mixing of isotopically distinct sources, but the tholeiites and alkalic basalts from Loihi do not show a well-developed inverse trend between Rb/Sr and /sup 87/Sr//sup 86/Sr that is characteristic of the later stages of Hawaiian volcanoes such as Haleakala and Koolau.

  4. Petrogenetic significance of high Fe/Mn ratios of the Cenozoic basalts from Eastern China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Cenozoic basalts from eastern China show commonly high Fe/Mn ratios (average = 68.6 ± 11.5) coupled with OIB-type trace element signature. The Cenozoic basalts form the northern margin and the southern margin of the North China Craton are studied in detail. Model calculations point out that the coupling feature of high Fe/Mn ratio with OIB-type trace element signature of these basalts cannot be produced by neither pyroxene/olivine crystallization nor remelting of previously melted mantle, but require partial melting of a garnet pyroxenite-rich mantle source. Combining these features of the Cenozoic basalts with the Phanerozoic lithospheric evolution of the eastern China, we suggest that the Cenozoic basalts were derived from a garnet pyroxenite-rich mantle source associated with continental crust delamination or oceanic crust subduction.

  5. Is plagioclase removal responsible for the negative Eu anomaly in the source regions of mare basalts?

    Science.gov (United States)

    Shearer, C. K.; Papike, J. J.

    1989-01-01

    The nearly ubiquitous presence of a negative Eu anomaly in the mare basalts has been suggested to indicate prior separation and flotation of plagioclase from the basalt source region during its crystallization from a lunar magma ocean (LMO). Are there any mare basalts derived from a mantle source which did not experience prior plagioclase separation? Crystal chemical rationale for REE substitution in pyroxene suggests that the combination of REE size and charge, M2 site characteristics of pyroxene, fO2, magma chemistry, and temperature may account for the negative Eu anomaly in the source region of some types of primitive, low TiO2 mare basalts. This origin for the negative Eu anomaly does not preclude the possibility of the LMO as many mare basalts still require prior plagioclase crystallization and separation and/or hybridization involving a KREEP component.

  6. 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.

  7. Petrogenetic significance of high Fe/Mn ratios of the Cenozoic basalts from Eastern China

    Institute of Scientific and Technical Information of China (English)

    ZHANG BinHui; LIU YongSheng; GAO Shan

    2008-01-01

    The Cenozoic basalts from eastern China show commonly high Fe/Mn ratios (average = 68.6 卤 11.5) coupled with OIB-type trace element signature. The Cenozoic basalts form the northern margin and the southern margin of the North China Craton are studied in detail. Model calculations point out that the coupling feature of high Fe/Mn ratio with OIB-type trace element signature of these basalts cannot be produced by neither pyroxene/olivine crystallization nor remelting of previously melted mantle, but require partial melting of a garnet pyroxenite-rich mantle source. Combining these features of the Cenozoic basalts with the Phanerozoic lithospheric evolution of the eastern China, we suggest that the Cenozoic basalts were derived from a garnet pyroxenite-rich mantle source associated with continental crust delamination or oceanic crust subduction.

  8. Glass and Mineral Chemistry of Northern Central Indian Ridge Basalts: Compositional Diversity and Petrogenetic Significance

    Institute of Scientific and Technical Information of China (English)

    Dwijesh RAY; Ranadip BANERJEE; Sridhar D IYER; Basavaraju BASAVALINGU; Subir MUKHOPADHYAY

    2009-01-01

    The glass and mineral chemistry of basalts examined from the northern central Indian ridge (NCIR) provides an insight into magma genesis around the vicinity of two transform faults: Vityaz (VT) and Vema (VM). The studied mid-ocean ridge basalts (MORBs) from the outer ridge flank (VT area) and a near-ridge seamount (VM area) reveal that they are moderately phyric plagioclase basalts composed of plagioclase (phenocryst [An_(60-90)] and groundmass [An_(35-79)]), olivine (FO_(81-88)), diopside (Wo_(45-51), En_(25-37), Fs_(14-24)), and titanomagnetite (FeO_t~63.75 wt% and TiO_2 ~22.69 wt%). The whole-rock composition of these basalts has similar Mg# [mole Mg/mole(Mg+Fe~(2+)] (VT basalt: ~0.56-0.58; VM basalt: ~0.57), but differ in their total alkali content (VT basalt: ~2.65; VM basalt: ~3.24). The bulk composition of the magma was gradually depleted in MgO and enriched in FeO_t, TiO_2, P_2O_5, and Na_2O with progressive fractionation, the basalts were gradually enriched in Y and Zr and depleted in Ni and Cr. In addition, the ΣREE of magma also increased with fractionation, without any change in the (La/ Yb)_N value. Glass from the VM seamount shows more fractionated characters (Mg#: 0.56-0.57) compared to the outer ridge flank lava of the VT area (Mg#: 0.63-0.65). This study concludes that present basalts experienced low-pressure crystallization at a relatively shallow depth. The geochemical changes in the NCIR magmas resulted from fractional crystallization at a shallow depth. As a consequence, spinel was the first mineral to crystallize at a pressure 10 kbar, followed by Fe-rich olivine at <10 kbar pressure.

  9. Basalt fiber reinforced porous aggregates-geopolymer based cellular material

    Science.gov (United States)

    Luo, Xin; Xu, Jin-Yu; Li, Weimin

    2015-09-01

    Basalt fiber reinforced porous aggregates-geopolymer based cellular material (BFRPGCM) was prepared. The stress-strain curve has been worked out. The ideal energy-absorbing efficiency has been analyzed and the application prospect has been explored. The results show the following: fiber reinforced cellular material has successively sized pore structures; the stress-strain curve has two stages: elastic stage and yielding plateau stage; the greatest value of the ideal energy-absorbing efficiency of BFRPGCM is 89.11%, which suggests BFRPGCM has excellent energy-absorbing property. Thus, it can be seen that BFRPGCM is easy and simple to make, has high plasticity, low density and excellent energy-absorbing features. So, BFRPGCM is a promising energy-absorbing material used especially in civil defense engineering.

  10. Voluminous Icelandic Basaltic Eruptions Appear To Cause Abrupt Global Warming

    Science.gov (United States)

    Ward, P. L.

    2011-12-01

    Beginning on June 21, 1783, Laki volcano in southern Iceland erupted 14.7 km3 basalt, ejecting 24 Mt SO_{2} into the stratosphere where it was blown eastward and northward and 98 Mt into the troposphere where the jet stream transported it southeastward to Europe. The "dry fog" observed in Europe with an estimated mean concentration of 60 ppbv SO2, raised daytime temperatures as much as 3.3^{o}C, causing the warmest July in England from 1659 when measurements began until 1983. SO2, tropospheric O_{3}, NO2, and fine ash absorb ultraviolet energy from the sun that causes the bonds between and within their atoms to oscillate at 47 times higher frequency than the bonds in CO_{2} absorbing infrared radiation. Temperature is proportional to the kinetic energy of these oscillations, i.e. the frequency squared. Thus these gases are raised to much higher temperatures than greenhouse gases. The Stefan-Boltzmann law says that radiation from these molecules is a constant times temperature raised to the fourth power. As a result, SO2 and ash radiate far more energy back to earth than CO_{2}, causing warming. Another way to look at the energy involved shows that 15 ppbv SO2 in the 0.3-0.42 μm wavelength band absorbs as much solar energy per unit volume as 388,000 ppbv CO_{2} absorbs infrared energy in the 12.7-17.5 μm band. Basaltic volcanoes such as Laki emit 10 to 100 times more SO2 than more evolved magmas and are less explosive, leaving most of the SO_{2} in the troposphere. All 14 Dansgaard-Oeschger (DO) sudden warmings between 46 and 11 ka are contemporaneous with the highest levels of sulfate in the GISP2 drill hole near Summit Greenland. These DO events typically warmed the northern hemisphere out of the ice age within decades, but as volcanism waned, ocean temperatures cooled the world back into an ice age within centuries. The world finally exited the ice age when voluminous volcanism continued from 11.6 to 9.6 ka. Basaltic table mountains or tuyas in Iceland document

  11. Melting of subducted basalt at the core-mantle boundary.

    Science.gov (United States)

    Andrault, Denis; Pesce, Giacomo; Bouhifd, Mohamed Ali; Bolfan-Casanova, Nathalie; Hénot, Jean-Marc; Mezouar, Mohamed

    2014-05-23

    The geological materials in Earth's lowermost mantle control the characteristics and interpretation of seismic ultra-low velocity zones at the base of the core-mantle boundary. Partial melting of the bulk lower mantle is often advocated as the cause, but this does not explain the nonubiquitous character of these regional seismic features. We explored the melting properties of mid-oceanic ridge basalt (MORB), which can reach the lowermost mantle after subduction of oceanic crust. At a pressure representative of the core-mantle boundary (135 gigapascals), the onset of melting occurs at ~3800 kelvin, which is ~350 kelvin below the mantle solidus. The SiO2-rich liquid generated either remains trapped in the MORB material or solidifies after reacting with the surrounding MgO-rich mantle, remixing subducted MORB with the lowermost mantle.

  12. 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.

  13. 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.

  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. 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 inflation 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

  16. High-Ti type N-MORB parentage of basalts from the south Andaman ophiolite suite, India

    Indian Academy of Sciences (India)

    Rajesh K Srivastava; R Chandra; Anant Shastry

    2004-12-01

    A complete dismembered sequence of ophiolite is well exposed in the south Andaman region that mainly comprises ultramafic cumulates, serpentinite mafic plutonic and dyke rocks, pillow lava, radiolarian chert, and plagiogranite. Pillow lavas of basaltic composition occupy a major part of the Andaman ophiolite suite (AOS). These basalts are well exposed all along the east coast of southern part of the south AOS. Although these basalts are altered due to low-grade metamorphism and late hydrothermal processes, their igneous textures are still preserved. These basalts are mostly either aphyric or phyric in nature. Aphyric type exhibits intersertal or variolitic textures, whereas phyric variety shows porphyritic or sub-ophitic textures. The content of alkalies and silica classify these basalts as sub-alkaline basalts and alkaline basalts. A few samples show basaltic andesite, trachybasalt, or basanitic chemical composition. High-field strength element (HFSE) geochemistry suggests that studied basalt samples are probably derived from similar parental magmas. Al2O3/TiO2 and CaO/TiO2 ratios classify these basalts as high-Ti type basalt. On the basis of these ratios and many discriminant functions and diagrams, it is suggested that the studied basalts, associated with Andaman ophiolite suite, were derived from magma similar to N-MORB and emplaced in the mid-oceanic ridge tectonic setting.

  17. A mantle plume beneath California? The mid-Miocene Lovejoy Flood Basalt, northern California

    Science.gov (United States)

    Garrison, N.J.; Busby, C.J.; Gans, P.B.; Putirka, K.; Wagner, D.L.

    2008-01-01

    The Lovejoy basalt represents the largest eruptive unit identified in California, and its age, volume, and chemistry indicate a genetic affinity with the Columbia River Basalt Group and its associated mantle-plume activity. Recent field mapping, geochemical analyses, and radiometric dating suggest that the Lovejoy basalt erupted during the mid-Miocene from a fissure at Thompson Peak, south of Susanville, California. The Lovejoy flowed through a paleovalley across the northern end of the Sierra Nevada to the Sacramento Valley, a distance of 240 km. Approximately 150 km3 of basalt were erupted over a span of only a few centuries. Our age dates for the Lovejoy basalt cluster are near 15.4 Ma and suggest that it is coeval with the 16.1-15.0 Ma Imnaha and Grande Ronde flows of the Columbia River Basalt Group. Our new mapping and age dating support the interpretation that the Lovejoy basalt erupted in a forearc position relative to the ancestral Cascades arc, in contrast with the Columbia River Basalt Group, which erupted in a backarc position. The arc front shifted trenchward into the Sierran block after 15.4 Ma. However, the Lovejoy basalt appears to be unrelated to volcanism of the predominantly calc-alkaline Cascade arc; instead, the Lovejoy is broadly tholeiitic, with trace-element characteristics similar to the Columbia River Basalt Group. Association of the Lovejoy basalt with mid-Miocene flood basalt volcanism has considerable implications for North American plume dynamics and strengthens the thermal "point source" explanation, as provided by the mantle-plume hypothesis. Alternatives to the plume hypothesis usually call upon lithosphere-scale cracks to control magmatic migrations in the Yellowstone-Columbia River basalt region. However, it is difficult to imagine a lithosphere-scale flaw that crosses Precambrian basement and accreted terranes to reach the Sierra microplate, where the Lovejoy is located. Therefore, we propose that the Lovejoy represents a rapid

  18. 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

  19. Tracing volatile loss during the eruption of individual flood basalt flows in the Columbia River Flood Basalt Province

    Science.gov (United States)

    Burton, K. W.; Vye, C.; Gannoun, A.; Self, S.

    2010-12-01

    Continental flood basalt (CFB) volcanism is characterised by the repeated eruption of huge batches of magma, producing enormous basalt provinces (105-106 km3) over relatively brief intervals of time, and delivering large masses of volcanic gas to the atmosphere. The release of gases and aerosols during CFB volcanism is thought to have had a significant impact on the atmosphere, ocean chemistry and climate [1-3]. The key factors influencing atmospheric chemistry and the environmental impact of CFB eruptions are the timing, mechanism and duration of volatile release during individual eruptions, but for the most part such information remains poorly known. The 187Re-187Os isotope system offers a highly sensitive tracer of the evolution of melt chemistry, and of the timing and mechanism of volatile release. This is partly because the contrasting behaviour of Re and Os during melting results in the extreme fractionation of parent/daughter (Re/Os) isotope ratios, thus magmatic phases can yield precise chronological information, and crustal rocks develop highly radiogenic isotope compositions that can be readily traced if assimilated [4]. Partly also because Re behaves as a highly volatile element during sub-aerial volcanism [5]. This study presents 187Re-187Os isotope data for rocks and minerals from two flows in the Columbia River Flood Basalt Group, one of the youngest flood basalt provinces that formed over a 2 million year interval in the Mid-Miocene. The 2,660 km3 Sand Hollow flow field displays small major and trace element variations, both laterally and vertically across the flow, indicative of fractional crystallisation, but the elemental data cannot be used to distinguish source variations and/or crustal contamination. However, Os isotopes indicate systematic crustal contamination over the timescale of an individual eruption, where the earliest formed lavas show the greatest degree of contamination. Isotope and elemental data for phenocryst phases from the 40

  20. Petrochemistry and origin of basalt breccia from Ban Sap Sawat area, Wichian Buri, Phetchabun, central Thailand

    Directory of Open Access Journals (Sweden)

    Phisit Limtrakun

    2013-08-01

    Full Text Available Thailand is usually considered to be controlled by escape tectonics associated with India-Asia collision during theLate Cenozoic, and basaltic volcanism took place in this extensional period. This volcanism generated both subaqueous andsubaerial lava flows with tholeiitic to alkalic basaltic magma. The subaqueous eruptions represented by the studied WichianBuri basalts, Ban Sap Sawat in particular, are constituted by two main types of volcanic lithofacies, including lava flows andbasalt breccias. The lava flows are commonly porphyritic with olivine and plagioclase phenocrysts and microphenocrysts,and are uncommonly seriate textured. The basalt breccias are strongly vitrophyric texture with olivine and plagioclasephenocrysts and microphenocrysts. Chemical analyses indicate that both lava flows and basalt breccias have similar geochemical compositions, signifying that they were solidified from the same magma. Their chondrite normalized REE patternsand N-MORB normalized patterns are closely analogous to the Early to Middle Miocene tholeiites from central Sinkhote-Alinand Sakhalin, northeastern margin of the Eurasian continent which were erupted in a continental rift environment. The originfor the Wichian Buri basalts show similarity of lava flows and basalt breccias, in terms of petrography and chemical compositions, signifying that they have been formed from the same continental within-plate, transitional tholeiitic magma.

  1. Explosive eruption of coal and basalt and the end-Permian mass extinction.

    Science.gov (United States)

    Ogden, Darcy E; Sleep, Norman H

    2012-01-03

    The end-Permian extinction decimated up to 95% of carbonate shell-bearing marine species and 80% of land animals. Isotopic excursions, dissolution of shallow marine carbonates, and the demise of carbonate shell-bearing organisms suggest global warming and ocean acidification. The temporal association of the extinction with the Siberia flood basalts at approximately 250 Ma is well known, and recent evidence suggests these flood basalts may have mobilized carbon in thick deposits of organic-rich sediments. Large isotopic excursions recorded in this period are potentially explained by rapid venting of coal-derived methane, which has primarily been attributed to metamorphism of coal by basaltic intrusion. However, recently discovered contemporaneous deposits of fly ash in northern Canada suggest large-scale combustion of coal as an additional mechanism for rapid release of carbon. This massive coal combustion may have resulted from explosive interaction with basalt sills of the Siberian Traps. Here we present physical analysis of explosive eruption of coal and basalt, demonstrating that it is a viable mechanism for global extinction. We describe and constrain the physics of this process including necessary magnitudes of basaltic intrusion, mixing and mobilization of coal and basalt, ascent to the surface, explosive combustion, and the atmospheric rise necessary for global distribution.

  2. Extreme Mantle Heterogeneity beneath the Jingpohu Area, Northeastern China-Geochemical Evidence of Holocene Basaltic Rock

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Holocene basaltic rocks of the Jingpohu area are located in the "Crater Forest" and Hamatang districts to the northwest of the Jingpohu Lake. Although there is only a distance of 15 km between the two districts, their petrological characteristics are very different: alkaline olivine basalt without any megacrysts in the former, and leucite tephrite with Ti-amphibole, phlogopite and anorthoclasite megacrysts in the latter. On the basis of their geochemical characteristics, the two types of basaltic rocks should belong to weakly sodian alkaline basalts. But leucite tephrite is characterized by higher Al2O3, Na2O and K2O, higher enrichment in light rare earth elements (LREE) and large ion lithophile elements (LILE), lower MgO and CaO, compatible elements and moderately compatible elements and lower Mg# values and Na/K ratios in comparison with alkaline olivine basalt. However, the two types of basaltic rocks have similar Sr, Nd, Pb isotopic compositions, which suggests that the mantle beneath the Jingpohu area was homogeneous before undergoing some geological processes about 3490 years ago. As the activity of the mantle plume led to different degrees of metasomatism, extreme mantle source heterogeneities occurred beneath the Jingpohu area. In comparison with alkaline olivine basalt, the leucite tephrite was derived from the more enriched mantle source region and resulted from strong metasomatism.

  3. Geochemical Characteristics and New Eruption Ages of Ruby-Related Basalts from Southeast Kenya

    Institute of Scientific and Technical Information of China (English)

    Tawatchai Chualaowanich; Chakkaphan Sutthirat; Visut Pisuttha-Arnond; Christoph Hauzenberger; Chinghua Lo; Tongyi Lee; Punya Charusiri

    2014-01-01

    Two ruby-related basaltic fields were recently discovered in the southeast region of Kenya, exposed in the Nguu and Ngulai Hills vicinities. These fields host abundant deep-seated xeno-liths, including corundum-bearing granulites. The basalts are alkaline affinity having compositions from foidrite to basanite. The Ngulai basalts have a wider range of SiO2 (38.2 wt.%-44.8 wt.%) cov-ering those of the Nguu basalts (38.7 wt.%-42.3 wt.%). This overlapping behavior also holds for other major oxides and trace elements, e.g., Al2O3, Na2O, K2O, Cr, Ni, Rb and Ga. The overall OIB-like in-compatible patterns with strong K depletion and slight spike of Ti enrichment signatures imply low degrees of partial melting of the upper mantle region source induced under a mantle plume-related process. The K-depletion signature indicates a residual K-bearing phase still retained in the source domain. Chondrite-normalized REE patterns exhibiting strong LREE enrichment without Eu anoma-lies suggest that plagioclase fractionation is insignificant. New40Ar/39Ar ages indicate eruption events occurred during the Pleistocene times, which are around 2 Ma for the Ngulai basalts and 0.9 to 1.6 Ma for the Nguu basalts. Clinopyroxene-basalt thermobarometric calculations yield the equilibriumP-T ranges of ~8-29 kbar and 1 200-1 450 oC.

  4. Measurement of the Dielectric Properties of Volcanic Scoria and Basalt at 9370 MHz

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yongchun; WANG Shijie; OUYANG Ziyuan; LI Xiongyao

    2005-01-01

    Dielectric data for volcanic scoria and basalt on the earth at microwave frequency are extremely sparse, and also crucial for volcanic terrains imaging, and development. In consideration of their similarity to lunar regolith (soils and rocks) in chemical and mineral composition, the dielectric data is significative for passive and active microwave remote sensing on the Moon. This study provides the data about the dielectric properties of three kinds of scoria and two kinds of basalt in China. The method put forward in this paper is also applicable for measuring the dielectric properties of dry rocks and other granular ground materials with low complex dielectric constants. Firstly, the authors measured the ε' and tanδvalues of strip specimens prepared from the mixture of scoria or basalt powder and polythene with the resonant cavity perturbation method at 9370 MHz. Secondly, from the ε' and tanδ values of the mixture, the ε's and ranδs values of solid scoria and basalt were calculated using Lichtenecker's mixture formulae. Finally, the effective complex dielectric constants, ε'e and tanδe, of scoria at different bulk densities were calculated. The results have shown that the ε's and tancδs values of all solid basaltic materials measured (both solid basaltic scoria or basalt) are approximately 7 and 0.05, respectively. With increasing bulk density of scoria, the ε'e and tanδe values of scoria increase significantly.

  5. Circumventing shallow air contamination in Mid Ocean Ridge Basalts

    Science.gov (United States)

    Mukhopadhyay, Sujoy; Parai, Rita; Tucker, Jonathan; Middleton, Jennifer; Langmuir, Charles

    2016-04-01

    Noble gases in mantle-derived basalts provide a rich portrait of mantle degassing and surface-interior volatile exchange. However, the ubiquity of shallow-level air contamination frequently obscures the mantle noble gas signal. In a majority of samples, shallow air contamination dominates the noble gas budget. As a result, reconstructing the variability in heavy noble gas mantle source compositions and inferring the history of deep recycling of atmospheric noble gases is difficult. For example, in the gas-rich popping rock 2ΠD43, 129Xe/130Xe ratios reach 7.7±0.23 in individual step-crushes, but the bulk composition of the sample is close to air (129Xe/130Xe of 6.7). Here, we present results from experiments designed to elucidate the source of shallow air contamination in MORBs. Step-crushes were carried out to measure He, Ne, Ar and Xe isotopic compositions on two aliquots of a depleted popping glass that was dredged from between the Kane and Atlantis Fracture Zones of the Mid-Atlantic Ridge in May 2012. One aliquot was sealed in ultrapure N2 after dredge retrieval, while the other aliquot was left exposed to air for 3.5 years. The bulk 20Ne/22Ne and 129Xe/130Xe ratios measured in the aliquot bottled in ultrapure N2 are 12.3 and 7.6, respectively, and are nearly identical to the estimated mantle source values. On the other hand, step crushes in the aliquot left exposed to air for several years show Ne isotopic compositions that are shifted towards air, with a bulk 20Ne/22Ne of 11.5; the bulk 129Xe/130Xe, however, was close to 7.6. These results indicate that lighter noble gases exchange more efficiently between the bubbles trapped in basalt glass and air, suggesting a diffusive or kinetic mechanism for the incorporation of the shallow air contamination. Importantly, in Ne-Ar or Ar-Xe space, step-crushes from the bottled aliquot display a trend that can be easily fit with a simple two-component hyperbolic mixing between mantle and atmosphere noble gases. Step

  6. Alteration in Hawaiian Drill Core: An analog for Martian basalts

    Science.gov (United States)

    Calvin, W. M.; Fraeman, A.; Ehlmann, B. L.; Lautze, N. C.

    2015-12-01

    The Humu'ula Groundwater Research Project (HGRP) drilled their first continuously-cored hole in the saddle region of the big island of Hawaii in March of 2013. Temperatures at the bottom of the hole were unexpectedly high and reached over 100C. The core traverses various lava flows, representing the shield-building phase of the island and the lithology is dominantly basalt with varying amounts of plagioclase and olivine phenocrysts. Logging of the core noted that discontinuous alteration became prevalent starting at ~ 1 km depth. In May of 2015 we collected 780 infrared spectra of the core from depths of 0.97 to 1.76 km using our portable field spectrometer with a contact probe and field of view of 10 mm. Many of the spectra are unaltered, showing mafic mineralogy (augite or augite with olivine). Minerals from aqueous alteration include clinochlore, micaceous minerals likely mixed with other common phyllic alteration products, and three groups of spectral types associated with zeolites. This suite of minerals suggests alteration was initiated from higher temperature and moderate pH fluids. Based on the field reconnaissance spectroscopy, 25 sections were cut that represent the alteration diversity for thin section and subsequent detailed petrologic analyses. Eight of these sections were examined using the Ultra-Compact Imaging Spectrometer (UCIS) prototype instrument at the Jet Propulsion Laboratory. UCIS collects spectra at 80 μm / pixel and identifies the same alteration mineralogy as the bulk samples, but clearly shows that the alteration occurs in veins and vugs. Unaltered olivine and pyroxene phenocrysts occur in the groundmass adjacent to highly altered vugs, and are preserved throughout the section surveyed. Given the limited alteration and abundant preservation of olivine to depths of 1.5 km, the core may be representative of alteration in moderate pH environments on Mars, where unaltered basaltic materials occur in close proximity to alteration products

  7. Calcium isotopic compositions of mid-ocean ridge basalts

    Science.gov (United States)

    Zhu, H.; Zhang, Z.; Sun, W.; Wang, G. Q.

    2015-12-01

    Previous studies have demonstrated that Earth's mantle has heterogeneous calcium isotopic compositions. But the reason why mantle has its heterogeneity remains uncertain. In general, δ44/40Ca values of mantle xenolith samples have a variation of >0.45‰. While ultramafic rocks, especially dunites, have higher δ44/40Ca values than volcanic rocks, and there is a positive correlation between δ44/40Ca and Ca/Mg. These phenomena imply that the heterogeneity of Ca isotopic compositions of mantle xenolith samples might result from different degrees of melt extraction, as indicated by large Ca isotopic fractionation between co-existing clinopyroxene and orthopyroxene. However, because ancient marine carbonate has its own unique calcium isotopic characteristics, recycling of even a small amount of ancient marine carbonates into the mantle could also cause the heterogeneity of Ca isotopes in Earth's mantle. This could be the reason why oceanic island basalts (OIB) have lighter Ca isotopic compositions than the mantle xenolith. Thus, the lighter Ca isotopic compositions in the mantle source cannot only be ascribed to magmatic processes. Therefore, it is more important to know calcium isotopic characteristics during partial melting and oceanic crust contamination.Mid-ocean ridge basalts (MORB) are formed from the partial melts of the upper mantle and are rarely affected by crustal contamination. Different types of MORB, including D-MORB, N-MORB and E-MORB, have experienced different degrees of partial melting and contamination of enriched end-members. Here we report calcium isotopic characteristic of different types of MORB, we believe it will be very helpful to understand the behaviors of Ca isotopes during partial melting and it is possible to provide further information to discover the reason why calcium isotopic compositions is heterogeneous in Earth's mantle. This work was supported by Natural Science Foundation of China (No. 41373007, No. 41490632 and No. 91328204

  8. Ar-Ar and U-Pb geochronology of Late Paleozoic basalts in western Guangxi and its constraints on the eruption age of Emeishan basalt magmatism

    Institute of Scientific and Technical Information of China (English)

    FAN Weiming; WANG Yuejun; PENG Touping; MIAO Laicheng; GUO Feng

    2004-01-01

    The Late Paleozoic layered or stratoid-layered basalts in western Guangxi have similar elemental and isotopic compositions to Emeishan high-Ti basalts. Whole-rock 40Ar/39Ar and SHRIMP zircon U-Pb dating were carried out for the representative basalt samples in three typical profiles in the area. Three basalts from the upper segment of Yangxu profile and lower segment of Yufeng and Min'an profiles yield the 40Ar/39Ar plateau ages of 253.6±0.4 Ma (20BS-71),255.4±0.4 Ma (20BS-99) and 256.2±0.8 Ma (20BS-119), respectively. Twenty-three analyses on 23 zircons of the basalt from the upper segment of Yangxu profile give a weighted mean 206pb/238U age of 253.7±6.1 Ma with an MSWD = 2.8.These new and published geochronological data for Emeishan large igneous province (LIP) indicate that the Emeishan LIP was initiated at ~260 Ma, voluminously erupted between 253 and 256 Ma, and possibly ended at ~251-253Ma' The age (251-260 Ma) is generally consistent with that of the associated environmental deterioration and mass extinction events at the end-Guadalupian and Permo-Triassic boundary. These precise geochronological data provide important constraints on the dominantly eruptive time of the Emeishan LIP and understanding of the distribution of Emeishan high-Ti basalts and its mantle plume dynamics.

  9. Assessing the potential for luminescence dating of basalts

    Science.gov (United States)

    Tsukamoto, S.; Duller, G.A.T.; Wintle, A.G.; Muhs, D.

    2011-01-01

    The possibility of dating basalt using luminescence was tested on four samples with independent age control from Cima volcanic field, California, with the ultimate aim of assessing whether the technique could be used to date sediments on the surface of Mars. Previous analysis of these samples had demonstrated that the infrared stimulated luminescence (IRSL) signal is most suitable for dating as it showed the lowest fading rate among various luminescence signals. In this study, changes in equivalent dose as a function of preheat are described. The ages for the two youngest Cima samples agree with the independent ages based on cosmogenic nuclide measurements (12.0 ?? 0.8 ka). In the two older samples (dated to 320 and 580 ka by K-Ar), the luminescence behaviour is more complex and the form of the IRSL decay curve is seen to vary with dose. Mathematical fitting is used to isolate two components and their intensities are used to produce dose response curves. The slower component yields a larger equivalent dose. However, even using this component and after correction for fading, the ages obtained for the older samples are younger than the K-Ar ages. ?? 2010 Elsevier B.V.

  10. Highly siderophile element abundances in Eoarchean komatiite and basalt protoliths

    Science.gov (United States)

    Frank, Elizabeth A.; Maier, Wolfgang D.; Mojzsis, Stephen J.

    2016-03-01

    Plume-derived, Mg-rich, volcanic rocks (komatiites, high-Mg basalts, and their metamorphic equivalents) can record secular changes in the highly siderophile element (HSE) abundances of mantle sources. An apparent secular time-dependent enrichment trend in HSE abundances from Paleoarchean to Paleoproterozoic mantle-derived rocks could represent the protracted homogenization of a Late Veneer chondritic contaminant into the pre-Late Veneer komatiite source. To search for a possible time dependence of a late accretion signature in the Eoarchean mantle, we report new data from rare >3700 Myr-old mafic and ultramafic schists locked in supracrustal belts from the Inukjuak domain (Québec, Canada) and the Akilia association (West Greenland). Our analysis shows that some of these experienced HSE mobility and/or include a cumulate component (Touboul et al. in Chem Geol 383:63-75, 2014), whereas several of the oldest samples show some of the most depleted HSE abundances measured for rocks of this composition. We consider these new data for the oldest documented rocks of komatiite protolith in light of the Late Veneer hypothesis.

  11. Field Detection of Chemical Assimilation in A Basaltic Lava Flow

    Science.gov (United States)

    Young, K. E.; Bleacher, J. E.; Needham, D. H.; Evans, C. A.; Whelley, P. L.; Scheidt, S. P.; Williams, D. A.; Rogers, A. D.; Glotch, T.

    2017-01-01

    Lava channels are features seen throughout the inner Solar System, including on Earth, the Moon, and Mars. Flow emplacement is therefore a crucial process in the shaping of planetary surfaces. Many studies, including some completed by members of this team at the December 1974 lava flow, have investigated the dynamics of lava flow emplacement, both on Earth and on the Moon and how pre-flow terrain can impact final channel morphology, but far fewer have focused on how the compositional characteristics of the substrate over which a flow was em-placed influenced its final flow morphology. Within the length of one flow, it is common for flows to change in morphology, a quality linked to rheology (a function of multiple factors including viscosi-ty, temperature, composition, etc.). The relationship between rheology and temperature has been well-studied but less is known about the relationship between an older flow's chemistry and how the interaction between this flow and the new flow might affect lava rheology and therefore emplacement dynamics. Lava erosion. Through visual observations of active terrestrial flows, mechanical erosion by flowing lava has been well-documented. Lava erosion by which flow composition is altered as the active lava melts and assimilates the pre-flow terrain over which it moves is also hypothesized to affect channel formation. However, there is only one previous field study that geochemically documents the process in recent basaltic flow systems.

  12. 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...... with 187Os/188Os of 0.1296). These low 187Os/188Os preclude significant shallow-level contamination from oceanic crust. The 187Os/188Os ratios for Jan Mayen lavas are less than PUM, severely limiting the presence of any continental crust in their mantle source. A positive correlation between 143Nd/144Nd...... and 187Os/188Os ratios in Iceland and Jan Mayen lavas likely reflects the presence in their source of ancient subcontinental lithosphere that has undergone incompatible trace element enrichment that did not affect the Re-Os system. In addition, the Jan Mayen lava isotopic signature cannot be explained...

  13. Possible solar noble-gas component in Hawaiian basalts

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Masahiko; McDougall, I.; Patterson, D.B.; Doulgeris, A. (Australian National Univ., Canberra (Australia). Research School of Earth Sciences); Clague, D.A. (Geological Survey, Menlo Park, CA (USA))

    1991-01-10

    The noble-gas elemental and isotopic composition in the Earth is significantly different from that of the present atmosphere, and provides an important clue to the origin and history of the Earth and its atmosphere. Possible candidates for the noble-gas composition of the primordial Earth include a solar-like component, a planetary-like component (as observed in primitive meteorites) and a component similar in composition to the present atmosphere. In an attempt to identify the contributions of such components, we have measured isotope ratios of helium and neon in fresh basaltic glasses dredged from Loihi seamount and the East Rift Zone of Kilauea. We find a systematic enrichment in {sup 20}Ne and {sup 21}Ne relative to {sup 22}Ne, compared with atmospheric neon. The helium and neon isotope signatures observed in our samples can be explained by mixing of solar, present atmospheric, radiogenic and nucleogenic components. These data suggest that the noble-gas isotopic composition of the mantle source of the Hawaiian plume is different from that of the present atmosphere, and that it includes a significant solar-like component. We infer that this component was acquired during the formation of the Earth. (author).

  14. Weathering Rinds and Soil Development on Basaltic Andesite, Guadeloupe

    Science.gov (United States)

    Sak, P. B.; Murphy, M.; Ma, L.; Engel, J.; Pereyra, Y.; Gaillardet, J.; Brantley, S. L.

    2014-12-01

    An oriented clast of basaltic andesite collected from the B horizon of a soil developed in a late Quaternary volcanoclastic debris flow on the eastern, windward side of Basse Terre Island, Guadeloupe exhibits weathering patterns like that observed in many clasts from tropical settings. The sample consists of unweathered core material overlain by a ~19 mm thick weathering rind and a narrow ≤ 2mm thick indurated horizon separating the outer portion of the rind from the overlying >10mm of soil matrix material. Elemental variations are constrained by a seven point bulk ICP-AES vertical transect extending from the core, across the rind and ~15 mm into the overlying soil matix and six parallel electron microprobe transections. The porous-hydrated fraction increases from the core to the rind to the surrounding soil from 7±4% to 45±18% to 60±15%, respectively. Like the well-studied clast from the nearby Bras David watershed (Sak et al., 2010) the isovolumetric transformation from core to rind material is marked by a narrow (Ba>K≈Mn>Mg>Si>Al≈P>Fe»Ti, consistent with the relative reactivity of phases in the clast from plagioclasepyroxeneglass>apatite>ilmenite. Unlike previously studied clasts, the preservation of the rind-soil interface permits characterization of weathering reactions between the weathering clast and surrounding soil matrix. The abrupt (weathering rind suggests that weathering processes active within clasts are distinct from surrounding soil formation processes.

  15. Glass-ceramics obtained by the crystallization of basalt

    Directory of Open Access Journals (Sweden)

    Cocić M.

    2010-01-01

    Full Text Available The possibility to obtain glass-ceramics from basalt from the locality on Vrelo (Kopaonik mt. is shown in this paper. The parent rock was ground to fraction -0.4 +0.1 mm, and then melted at 1250 - 1300°C. The crystallization melted bazaltic glass at 950°C during the time interval of 3 hours caused synthesis of a glass-ceramic material with a microstructure that has excellent mechanical properties according to the determined dynamic modulus of elasticity and uniaxial compresive strength. The phase composition of the obtained glass ceramic material was determined by XRPD using Rietveld refinement and SEM. Two phases were found: pyroxene which corresponds to omphacite of the composition (Na0.199 K0.180 Ca0.471 Mg0.2491.1(Mg0.271Fe0.299Al0.4301.0(Si1.704Ti0.046Al0.2502.0O6 and glass with an approximate relationship 69:31.

  16. Structural change in molten basalt at deep mantle conditions.

    Science.gov (United States)

    Sanloup, Chrystèle; Drewitt, James W E; Konôpková, Zuzana; Dalladay-Simpson, Philip; Morton, Donna M; Rai, Nachiketa; van Westrenen, Wim; Morgenroth, Wolfgang

    2013-11-07

    Silicate liquids play a key part at all stages of deep Earth evolution, ranging from core and crust formation billions of years ago to present-day volcanic activity. Quantitative models of these processes require knowledge of the structural changes and compression mechanisms that take place in liquid silicates at the high pressures and temperatures in the Earth's interior. However, obtaining such knowledge has long been impeded by the challenging nature of the experiments. In recent years, structural and density information for silica glass was obtained at record pressures of up to 100 GPa (ref. 1), a major step towards obtaining data on the molten state. Here we report the structure of molten basalt up to 60 GPa by means of in situ X-ray diffraction. The coordination of silicon increases from four under ambient conditions to six at 35 GPa, similar to what has been reported in silica glass. The compressibility of the melt after the completion of the coordination change is lower than at lower pressure, implying that only a high-order equation of state can accurately describe the density evolution of silicate melts over the pressure range of the whole mantle. The transition pressure coincides with a marked change in the pressure-evolution of nickel partitioning between molten iron and molten silicates, indicating that melt compressibility controls siderophile-element partitioning.

  17. On the puzzle of space weathering alteration of basaltic asteroids

    CERN Document Server

    Marchi, S; Lazzarin, M; Magrin, S

    2010-01-01

    The majority of basaltic asteroids are found in the inner main belt, although a few have also been observed in the outer main belt and near-Earth space. These asteroids -referred to as V-types- have surface compositions that resemble that of the 530km sized asteroid Vesta. Besides the compositional similarity, dynamical evidence also links many V-type asteroids to Vesta. Moreover, Vesta is one of the few asteroids to have been identified as source of specific classes of meteorites, the howardite, eucrite, diogenite achondrites (HEDs). Despite the general consensus on the outlined scenario, several questions remain unresolved. In particular, it is not clear if the observed spectral diversity among Vesta, V-types and HEDs is due to space weathering, as is thought to be the case for S-type asteroids. In this paper, SDSS photometry is used to address the question of whether the spectral diversity among candidate V-types and HEDs can be explained by space weathering. We show that visible spectral slopes of V-types...

  18. 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.

  19. 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.

  20. Petrogenesis of Mt. Baker basalts (Cascade arc): Constraints from thermobarometry, phase equilibria, trace elements and isotopes

    Science.gov (United States)

    Mullen, E. K.; McCallum, I. S.

    2010-12-01

    Primitive arc basalts provide information on sub-arc mantle compositions and processes. The relative abundance of basalts in the Cascade arc decreases northward, and basalts are rare in the most northerly segment of the arc (Garibaldi belt) where the Mt. Baker volcanic field (MBVF) is located. Following reconstruction of the compositions of the primary basalts at MBVF (olivine addition ± plag subtraction), we have applied phase equilibria and forward-modeled trace element abundances and isotope ratios to obtain petrogenetic constraints. The most primitive lavas are the Sulphur Cr, Lk Shannon, and Park Butte basalts and the Hogback, Tarn Plateau, and Cathedral Crag basaltic andesites, ranging from 716 to 10 ka. Most erupted peripheral to the major centers. Spinel/olivine and Fe-Ti oxide oxybarometry indicate redox states of ~QFM + 1 corresponding to Fe3+/ΣFe = 0.20. Mg# ranges from 51 to 71. The lavas are medium-K and similar to calc-alkaline basalts and high-Mg basaltic andesites from the High Cascades. MBVF basalts have higher MgO and lower CaO and Al2O3 than typical CAB and HAOT, grading to alkalic compositions with TiO2 and Na2O of up to 1.65 and 5.4 wt%, respectively (Sulphur Cr). Phenocryst contents are 5 to 33% (plag + olivine ± cpx) and the lavas are holo- or hypocrystalline with glass contents of up to 15%. The whole rocks are close to equilibrium with olivine cores (range Fo 87-68). Plagioclase cores range from An 88-68. Reconstructed primary basalt compositions give liquidus T and P values (from olivine-liquid equilibria and silica activities) ranging from 1280°C and 1 GPa (Tarn Plateau) to 1350°C and 1.4 GPa (Sulphur Cr), corresponding to the upper mantle above the core of the mantle wedge. These estimates take into account the 1 to 3 wt% initial H2O contents of the basalts calculated using plagioclase cores. Phase equilibria of the primary basalts indicate a similar pressure range of 1-2 GPa and indicate a residual mantle assemblage of harzburgite

  1. Melt migration in basalt columns driven by crystallization-induced pressure gradients.

    Science.gov (United States)

    Mattsson, Hannes B; Caricchi, Luca; Almqvist, Bjarne S G; Caddick, Mark J; Bosshard, Sonja A; Hetényi, György; Hirt, Ann M

    2011-01-01

    The structure of columnar-jointed lava flows and intrusions has fascinated people for centuries and numerous hypotheses on the mechanisms of formation of columnar jointing have been proposed. In cross-section, weakly developed semicircular internal structures are a near ubiquitous feature of basalt columns. Here we propose a melt-migration model, driven by crystallization and a coeval specific volume decrease inside cooling and solidifying columns, which can explain the observed macroscopic features in columnar-jointed basalts. We study basalts from Hrepphólar (Iceland), combining macroscopic observations, detailed petrography, thermodynamic and rheological modelling of crystallization sequences, and Anisotropy of Magnetic Susceptibility (AMS) of late crystallizing phases (that is, titanomagnetite). These are all consistent with our proposed model, which also suggests that melt-migration features are more likely to develop in certain evolved basaltic lava flows (with early saturation of titanomagnetite), and that the redistribution of melt within individual columns can modify cooling processes.

  2. Combined Thickness of the Modeled Saddle Mountains Basalt and Mabton Interbed Geomodel Units (smthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The smthk_f grid represents the modeled combined thickness of the Saddle Mountains Basalt and Mabton interbed geomodel units at a 500 foot resolution. It is one grid...

  3. Fluid Composititon and Carbon & Oxygen Isotope Geochemistry of Cenozoic Alkali Basalts in Eastern China

    Institute of Scientific and Technical Information of China (English)

    张铭杰; 王先彬; 等

    1999-01-01

    The fluid compositions of Cenozoic alkali basalts in eastern China have been determined by the pyrolysis-MS method,meanwhile the carbon and oxygen isotopic compositions of CO2 released from these samples at different heating temperatures have been analyzed by the vacuum step-heating method.The data show the volatiole heterogeneity in upper-mantle sources and different evolution trends of alkali basaltic magmas in eastern China,and these alkali basaltic magmas may be generated in the oxidizing milieu,as compared with mantle-derived xenoliths in these alkali basalts,and exotic volatile components were mixed into these magmas in the process of their formation and development.

  4. INVESTIGATION OF SOFTENING AGENT PREPARATION AND PERFORMANCE OF HANDMADE ECOCOMPOSITES WITH CONIFEROUS WOOD AND BASALT FIBERS

    Institute of Scientific and Technical Information of China (English)

    GuangjianWang; DekuShang; KailiangZhang; LinnaHu; ZhenhuaGuo

    2004-01-01

    In this investigation, basalt mineral fiber softening agent was prepared in order to obtain desirable flexible performance. Stability and physical chemistry natures of softening agent were evaluated by particle size distribution, dilution, storage and folding endurance etc. Constitutes of basalt and wood fibers were determined by energy dispersion analysis X-ray which served as an accessory of scanning electron microscopy (SEM-EDAX). Naturally degradable ecocomposite was prepared by basalt and wood fibers. The results of SEM observation illustrated that the wood and basalt fibers were blended uniformly. The impact factors of beating degree, content of wood fibers and adhesive etc. were discussed. The structure of the naturally degradable ecocomposite was contrasted with that of pure wood fibers and the cause of excellent filtration performance was analyzed. Compared with traditional methods, it was of saving wood resource, a large amount of water and reducing second pollution. As a consequence, the ecocomposite harmonized with environment and accorded with requirement of benignly friendly environment.

  5. 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.

    Mineral chemical analyses of transitional basalts from the Carlsberg Ridge show plagioclase (An approximately 87 mole %), phenocrysts, and microphenocrysts have a K sub(2)O depletion as compared to the laths (approximately 79 mole %). Olivine...

  6. Mechanical Properties of Wood Flour Reinforced High Density Polyethylene Composites with Basalt Fibers

    Directory of Open Access Journals (Sweden)

    Guojun LU

    2014-12-01

    Full Text Available Basalt fibers (BFs were surface-treated with a vinyl triethoxy silane coupling agent to improve the mechanical properties of wood fiber-reinforced high density polyethylene (HDPE composites. Basalt fibers were characterized with SEM and FT-IR. The effects of the basalt fiber content and apparent morphology on the mechanical properties of the hybrid composites were investigated in this paper. The results show that the BF coated with the vinyl triethoxy silane coupling agent resulted in an improvement in mechanical properties due to the increased interfacial compatibility between the BF and HDPE. The flexural strength and impact properties significantly increased with 4 wt.% modified basalt fibers. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6441

  7. Differential weathering of basaltic and granitic catchments from concentration-discharge relationships

    Science.gov (United States)

    Ibarra, Daniel E.; Caves, Jeremy K.; Moon, Seulgi; Thomas, Dana L.; Hartmann, Jens; Chamberlain, C. Page; Maher, Kate

    2016-10-01

    A negative feedback between silicate weathering rates and climate is hypothesized to play a central role in moderating atmospheric CO2 concentrations on geologic timescales. However, uncertainty regarding the processes that regulate the operation of the negative feedback limits our ability to interpret past variations in the ocean-atmosphere carbon cycle. In particular, the mechanisms that determine the flux of weathered material for a given climatic state are still poorly understood. Here, we quantify the processes that determine catchment-scale solute fluxes for two lithologic end-members-basalt and granite-by applying a recently developed solute production model that links weathering fluxes to both discharge and the reactivity of the weathering material. We evaluate the model against long-term monitoring of concentration-discharge relationships from basaltic and granitic catchments to determine the parameters associated with solute production in each catchment. Higher weathering rates in basaltic catchments relative to granitic catchments are driven by differing responses to increases in runoff, with basaltic catchments showing less dilution with increasing runoff. In addition, results from the solute production model suggest that thermodynamic constraints on weathering reactions could explain higher concentrations in basaltic catchments at lower runoff compared to granitic catchments. To understand how the response to changing discharge controls weathering fluxes under different climatic states, we define basalt/granite weatherability as the ratio of the basalt catchment flux to the granite catchment flux. This weatherability is runoff-dependent and increases with increasing runoff. For HCO3- and SiO2(aq) fluxes, for modern global runoff, the derived mean basalt/granite weatherability is 2.2 (1.3-3.7, 2σ) and 1.7 (1.6-2.1, 2σ), respectively. Although we cannot determine the array of individual processes resulting in differences among catchments, the relative

  8. Confining caesium in expanded natural Perlite

    OpenAIRE

    Rehspringer, Jean Luc; Balencie, J.; Vilminot, Serge; Burger, Didier; Boos, Anne; Estournès, Claude

    2007-01-01

    International audience; We present the potential use of expanded perlite, a metastable amorphous hydrated aluminum silicate, as a permanent medium for the long-term confinement of caesium. A simple loading by mixing an aqueous caesium nitrate solution and expanded perlite at 300K followed by thermal annealing leads to 96% sintering. The formation of pollucite, CsAlSi2O6, a naturally occurring mineral phase, appears as the crystalline phase embedded in a glassy phase. Leaching tests on the res...

  9. Fracture Analysis of the Ribeirao Preto Basalts, SP: Application for Developing a Conceptual Hydrogeological Model

    Directory of Open Access Journals (Sweden)

    Amélia João Fernandes

    2011-12-01

    Full Text Available The study of the physical geology and geochemistry of the Ribeirão Preto basalts was part of a hydrogeologicalresearch, which aimed to investigate the recharge of the Guarani Aquifer System (SAG through the basalts of the SerraGeral Aquifer (ASG, a project shortly named FRATASG. In addition to the hydrogeological research, a detailed geologicalinvestigation was conducted to develop a conceptual model of groundwater fl ow in complex aquifers, as is the case ofthe fractured basalts of the ASG. Therefore, this study included a thorough structural survey and analysis of horizontaland subvertical fractures, which resulted in the identifi cation of four tectonic events. It was concluded that the verticalgroundwater flow is important up to 10 m in depth and, secondarily, up to 25 m. Horizontal fl ow, more evident up to thedepth of 50 m, predominates and occurs along sub-horizontal fractures, which occur mainly at the contact between basalts2 and 3 and in its vicinity. Because the great majority of subvertical fractures do not propagate into the vesicular layers,which occur at the basalt contacts, it is suggested that these layers act as regional hydraulic barriers, and greatly hamperthe recharge of the SAG through the ASG. As a consequence, groundwater flow in the basalt stack is of stratabound type,as it occurs mainly along the basalt contacts. Based on diagnostic features of the fl ow, it is proposed in this study that the vertical flow,which crosses the basalt stack reaching the SAG, is local and probably occurs along NE structures.

  10. Investigation of Mechanical Properties of Basalt Particle-Filled SMC Composites

    OpenAIRE

    2016-01-01

    Basalt particles have been investigated as a novel additive for the production of glass fibre reinforced composite using sheet moulding compound (SMC) method. Compared to the CaCO3 that are widely used as filler in the SMC composite, the resulting composites exhibit improved mechanical properties. The tensile strength increased by approximately 15%, whereas the flexural strength was enhanced by 8% in SMC composites prepared by basalt particles. Examination of the surface morphology and interf...

  11. Cristallochimie du pyroxène dans les komatiites et basaltes lunaires

    OpenAIRE

    Bouquain, Sébastien

    2008-01-01

    RAS; Zoned pyroxene crystals with pigeonite cores and augite mantles crystallize in komatiites and lunar basalts. To understand the origin and conditions of crystallization of these unusual pyroxenes, we chosed both experimental and analytical sudies. Our experiments in the CMAS system were able to reproduce the zoned acicular pigeonite-augite crystals characteristic of komatiites and lunar basalts. We studied a series of samples of komatiites from the Archean (2.7 Ga) Abitibi greenstone belt...

  12. Hydrothermal alteration and diagenesis of terrestrial lacustrine pillow basalts: Coordination of hyperspectral imaging with laboratory measurements

    Science.gov (United States)

    Greenberger, Rebecca N; Mustard, John F; Cloutis, Edward A; Mann, Paul; Wilson, Janette H.; Flemming, Roberta L; Robertson, Kevin; Salvatore, Mark R; Edwards, Christopher

    2015-01-01

    We investigate an outcrop of ∼187 Ma lacustrine pillow basalts of the Talcott Formation exposed in Meriden, Connecticut, USA, focusing on coordinated analyses of one pillow lava to characterize the aqueous history of these basalts in the Hartford Basin. This work uses a suite of multidisciplinary measurements, including hyperspectral imaging, other spectroscopic techniques, and chemical and mineralogical analyses, from the microscopic scale up to the scale of an outcrop.

  13. Mechanical Properties of a Unidirectional Basalt-Fiber-Reinforced Plastic Under a Loading Simulating Operation Conditions

    Science.gov (United States)

    Lobanov, D. S.; Slovikov, S. V.

    2017-01-01

    The results of experimental investigations of unidirectional composites based on basalt fibers and different marks of epoxy resins are presented. Uniaxial tensile tests were carried out using a specimen fixation technique simulating the operation conditions of structures. The mechanical properties of the basalt-fiber-reinforced plastics (BFRPs) were determined. The diagrams of loading and deformation of BFRP specimens were obtain. The formulations of the composites with the highest mechanical properties were revealed.

  14. Depth of volcanic basalt degassing forecasted from CO2 fluid inclusions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fluid inclusions have recorded the history of degassing in basalt. Some fluid inclusions in olivine and pyroxene phenocrysts of basalt were analyzed by micro-thermometry and Raman spectroscopy in this paper. The experimental results showed that many inclusions are present almost in a pure CO2 system. The densities of some CO2 inclusions were computed in terms of Raman spectroscopic characteristics of CO2 Fermi resonance at room temperature. Their densities change over a wide range, but mainly between 0.044 g/cm3 and 0.289 g/cm3. Their micro-thermometric measurements showed that the CO2 inclusions examined reached homogenization between 1145.5℃ and 1265℃. The mean value of homogenization temperatures of CO2 inclusions in basalts is near 1210℃. The trap pressures (depths) of inclusions were computed with the equation of state and computer program. Distribution of the trap depths makes it know that the degassing of magma can happen over a wide pressure (depth) range, but mainly at the depth of 0.48 km to 3.85 km. This implicates that basalt magma experienced intensive degassing and the CO2 gas reservoir from the basalt magma also may be formed in this range of depths. The results of this study showed that the depth of basalt magma degassing can be forecasted from CO2 fluid inclusions, and it is meaningful for understanding the process of magma degassing and constraining the inorganogenic CO2 gas reservoir.

  15. Carbon sequestration via reaction with basaltic rocks: geochemical modeling and experimental results

    Science.gov (United States)

    Rosenbauer, Robert J.; Thomas, Burt; Bischoff, James L.; Palandri, James

    2012-01-01

    Basaltic rocks are potential repositories for sequestering carbon dioxide (CO2) because of their capacity for trapping CO2 in carbonate minerals. We carried out a series of thermodynamic equilibrium models and high pressure experiments, reacting basalt with CO2-charged fluids over a range of conditions from 50 to 200 °C at 300 bar. Results indicate basalt has a high reactivity to CO2 acidified brine. Carbon dioxide is taken up from solution at all temperatures from 50 to 200 °C, 300 bar, but the maximum extent and rate of reaction occurs at 100 °C, 300 bar. Reaction path simulations utilizing the geochemical modeling program CHILLER predicted an equilibrium carbonate alteration assemblage of calcite, magnesite, and siderite, but the only secondary carbonate identified in the experiments was a ferroan magnesite. The amount of uptake at 100 °C, 300 bar ranged from 8% by weight for a typical tholeite to 26% for a picrite. The actual amount of CO2 uptake and extent of rock alteration coincides directly with the magnesium content of the rock suggesting that overall reaction extent is controlled by bulk basalt Mg content. In terms of sequestering CO2, an average basaltic MgO content of 8% is equivalent to 2.6 × 108 metric ton CO2/km3 basalt.

  16. Geochemical Characteristics and Tectonic Setting of the Laohushan Basalts, North Qilian Mountains

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Ordovician Laohushan ophiolite, located in the eastern partof the North Qilian Mountains, is mainly composed of meta-peridotites, gabbros and basalts alternating with sediments. The sediments are mainly turbidites, in cluding sandstones, siltstones, cherts etc. Major elements show that the basalts are subalkaline tholeiites and may be analogous to ocean-floor basalts. Except a few N-MORBs, most of the basalts are E-MORBs as indicated by incompatible element ratios such as (La/Ce)N, La/Sm, Ce/Zr, Zr/Y and Zr/Nb. Negative Nb anomaly is common but negative Zr, Hf and Ti anomalies are quite rare. Based on the geochemical characteristics, it is suggested that the Laohushan basalts were formed in a back-arc basin. eNd (t) of the basalts ranges between +3.0 and +8.9 and (87Sr/86Sr)i ranges between 0.7030 and 0.7060, indicating a depleted mantle source which was mixed with more or less enriched mantle components. Further more, the petrography of the sandstones and geochemistry of the cherts suggest that the sediments were deposited near a continental margin.

  17. Primitive and contaminated basalts from the Southern Rocky Mountains, U.S.A

    Science.gov (United States)

    Doe, B.R.; Lipman, P.W.; Hedge, C.E.; Kurasawa, H.

    1969-01-01

    Basalts in the Southern Rocky Mountains province have been analyzed to determine if any of them are primitive. Alkali plagioclase xenocrysts armored with calcic plagioclase seem to be the best petrographic indicator of contamination. The next best indicator of contamination is quartz xenocrysts armored with clinopyroxene. On the rocks and the region studied, K2O apparently is the only major element with promise of separating primitive basalt from contaminated basalt inasmuch as it constitutes more than 1 % in all the obviously contaminated basalts. K2O: lead (> 4 ppm) and thorium (> 2 ppm) contents and Rb/Sr (> 0.035) are the most indicative of the trace elements studied. Using these criteria, three basalt samples are primitive (although one contains 1.7% K2O) and are similar in traceelement contents to Hawaiian and Eastern Honshu, Japan, primitive basalts. Contamination causes lead isotope ratios, 206Pb/204Pb and 208Pb/204Pb, to become less radiogenic, but it has little or no effect on 87Sr/86Sr. We interpret the effect on lead isotopes to be due to assimilation either of lower crustal granitic rocks, which contain 5-10 times as much lead as basalt and which have been low in U/Pb and Th/Pb since Precambrian times, or of upper crustal Precambrian or Paleozoic rocks, which have lost much of their radiogenic lead because of heating prior to assimilation. The lack of definite effects on strontium isotopes may be due to the lesser strontium contents of granitic crustal rocks relative to basaltic rocks coupled with lack of a large radiogenic enrichment in the crustal rocks. Lead isotope ratios were found to be less radiogenic in plagioclase separates from an obviously contaminated basalt than in the primitive basalts. The feldspar separate that is rich in sodic plagioclase xenocrysts was found to be similar to the whole-rock composition for 206Pb/204Pb and 208Pb/204Pb whereas a more dense fraction probably enriched in more calcic plagioclase phenocrysts is more similar

  18. Fractionation of yttrium and holmium during basaltic soil weathering

    Science.gov (United States)

    Thompson, Aaron; Amistadi, Mary Kay; Chadwick, Oliver A.; Chorover, Jon

    2013-10-01

    The anomalously low affinity of yttrium (Y) for iron (Fe) (oxyhydr)oxides relative to lanthanides with similar ionic radius (e.g., Ho) has been demonstrated in experiments with isolated Fe minerals and in a variety of marine systems that contain high concentrations of solid phase Fe. However, it has not previously been demonstrated to occur during soil genesis, despite the common observation that many soils become enriched in Fe over time. We hypothesized that Y would become progressively depleted in soils relative to Ho with increased weathering. Since, trivalent Y has an anomalously low Misono softness relative to other trivalent ions included in the rare earth element and yttrium group (REY3+), we also investigated whether soil REY fractionation reflects variation in Misono softness. To test this, we measured trends in total REY concentrations for Hawaiian soils derived from basaltic parent materials aged 0.3-4100 ky, and measured REYs released from the same samples during short-time (3 h) dissolution experiments conducted as part of a previous investigation linking dissolution with surface charge properties (Chorover et al., 2004). The chondrite-normalized Y/Ho ratios in the parent Hawaiian basalt (Chond[Y/Ho] = 0.998) and continental dust (Chond[Y/Ho] = 0.994) inputs are remarkably similar, and thus we can interpret deviations from Chond[Y/Ho] ∼ 1.0 to result from soil biogeochemical processes and not source mixing. Between 0.3 and 20 ky, the Chond[Y/Ho] ratio of the subsurface soils decreased from 0.96 ± 0.07(2σ) to 0.71 ± 0.05, and then remained unchanged across the rest of the weathering sequence. In contrast, the Chond[Y/Ho] ratio of the surface soils decreased from 0.99 ± 0.07 to 0.76 ± 0.05 at 150 ky and then, most likely due to continued dust inputs, increased to 1.04 ± 0.07 in the oldest soils. Analysis of the short-time dissolution experiments revealed preferential release of Y relative to Ho (and also La relative Pr) at intermediate pH where

  19. Expanded Schools: Developing Mindsets to Support Academic Success. Research Brief

    Science.gov (United States)

    ExpandED Schools, 2014

    2014-01-01

    The national demonstration of ExpandED Schools, The After-School Corporation's (TASC) expanded learning model, was launched in 2011-12 in New York City, Baltimore, and New Orleans. The ExpandED Schools demonstration is being evaluated by Policy Studies Associates (PSA) and is rolling out at a time when there is heightened awareness among…

  20. Experimental constraints on the outgassing dynamics of basaltic magmas

    Science.gov (United States)

    Pioli, L.; Bonadonna, C.; Azzopardi, B. J.; Phillips, J. C.; Ripepe, M.

    2012-03-01

    The dynamics of separated two-phase flow of basaltic magmas in cylindrical conduits has been explored combining large-scale experiments and theoretical studies. Experiments consisted of the continuous injection of air into water or glucose syrup in a 0.24 m diameter, 6.5 m long bubble column. The model calculates vesicularity and pressure gradient for a range of gas superficial velocities (volume flow rates/pipe area, 10-2-102 m/s), conduit diameters (100-2 m), and magma viscosities (3-300 Pa s). The model is calibrated with the experimental results to extrapolate key flow parameters such as Co (distribution parameter) and Froude number, which control the maximum vesicularity of the magma in the column, and the gas rise speed of gas slugs. It predicts that magma vesicularity increases with increasing gas volume flow rate and decreases with increasing conduit diameter, until a threshold value (45 vol.%), which characterizes churn and annular flow regimes. Transition to annular flow regimes is expected to occur at minimum gas volume flow rates of 103-104 m3/s. The vertical pressure gradient decreases with increasing gas flow rates and is controlled by magma vesicularity (in bubbly flows) or the length and spacing of gas slugs. This study also shows that until conditions for separated flow are met, increases in magma viscosity favor stability of slug flow over bubbly flow but suggests coexistence between gas slugs and small bubbles, which contribute to a small fraction of the total gas outflux. Gas flow promotes effective convection of the liquid, favoring magma homogeneity and stable conditions.

  1. Detection of Euryarchaeota and Crenarchaeota in an oxic basalt aquifer.

    Science.gov (United States)

    O'Connell, Seán P; Lehman, R Michael; Snoeyenbos-West, Oona; Winston, Vern D; Cummings, David E; Watwood, Mary E; Colwell, Frederick S

    2003-05-01

    Groundwater from an oxic, fractured basalt aquifer was examined for the presence of Archaea. DNA was extracted from cells concentrated from groundwater collected from five wells penetrating the eastern Snake River Plain Aquifer (Idaho, USA). Polymerase chain reaction (PCR) amplification of 16S rDNA was performed with Archaea-specific primers using both nested (ca. 200-bp product) and direct (ca. 600-bp product) PCR approaches. Estimates of the archaeal diversity were made by separating PCR products from all five wells by denaturing gradient gel electrophoresis (DGGE) and phylogenetic analysis of partial 16S rDNA sequences from two wells was performed following cloning procedures. Archaea were detected in all wells and the number of DGGE bands per well ranged from two to nine and varied according to PCR approach. There were 30 unique clonal 16S rDNA partial sequences (ca. 600 bp) within a total of 100 clones that were screened from two wells. Twenty-two of the 16S rDNA fragments recovered from the aquifer were related to the Crenarchaeota and Euryarchaeota kingdoms (one large clade of clones in the former and six smaller clades in the latter), with sequences ranging from 23.7 to 95.4% similar to those found in other investigations. The presence of potentially thermophilic or methanogenic Archaea in this fully oxic aquifer may be related to deep thermal sources or elevated dissolved methane concentrations. Many sequences were similar to those that represent non-thermophilic Crenarchaeota of which there are no known cultured members and therefore no putative function.

  2. Grain shape of basaltic ash populations: implications for fragmentation

    Science.gov (United States)

    Schmith, Johanne; Höskuldsson, Ármann; Holm, Paul Martin

    2017-02-01

    Here, we introduce a new quantitative method to produce grain shape data of bulk samples of volcanic ash, and we correlate the bulk average grain shape with magma fragmentation mechanisms. The method is based on automatic shape analysis of 2D projection ash grains in the size range 125-63 μm. Loose bulk samples from the deposits of six different basaltic eruptions were analyzed, and 20,000 shape measurements for each were obtained within 45 min using the Particle Insight™ dynamic shape analyzer (PIdsa). We used principal component analysis on a reference grain dataset to show that circularity, rectangularity, form factor, and elongation best discriminate between the grain shapes when combined. The grain population data show that the studied eruptive environments produce nearly the same range of grain shapes, although to different extents. Our new shape index (the regularity index (RI)) places an eruption on a spectrum between phreatomagmatic and dry magmatic fragmentation. Almost vesicle-free Surtseyan ash has an RI of 0.207 ± 0.002 (2σ), whereas vesiculated Hawaiian ash has an RI of 0.134 ± 0.001 (2σ). These two samples define the end-member RI, while two subglacial, one lacustrine, and another submarine ash sample show intermediate RIs of 0.168 ± 0.002 (2σ), 0.175 ± 0.002 (2σ), 0.187 ± 0.002 (2σ), and 0.191 ± 0.002 (2σ), respectively. The systematic change in RI between wet and dry eruptions suggests that the RI can be used to assess the relative roles of magmatic vs. phreatomagmatic fragmentation. We infer that both magmatic and phreatomagmatic fragmentation processes played a role in the subglacial eruptions.

  3. Experimental study into the petrogenesis of crystal-rich basaltic to andesitic magmas at Arenal volcano

    Science.gov (United States)

    Parat, F.; Streck, M. J.; Holtz, F.; Almeev, R.

    2014-08-01

    Arenal volcano is nearly unique among arc volcanoes with its 42 year long (1968-2010) continuous, small-scale activity erupting compositionally monotonous basaltic andesites that also dominate the entire, ~7000 year long, eruptive history. Only mineral zoning records reveal that basaltic andesites are the result of complex, open-system processes deriving minerals from a variety of crystallization environments and including the episodic injections of basalt. The condition of the mafic input as well as the generation of crystal-rich basaltic andesites of the recent, 1968-2010, and earlier eruptions were addressed by an experimental study at 200 MPa, 900-1,050 °C, oxidizing and fluid-saturated conditions with various fluid compositions [H2O/(H2O + CO2) = 0.3-1]. Phase equilibria were determined using a phenocryst-poor (~3 vol%) Arenal-like basalt (50.5-wt% SiO2) from a nearby scoria cone containing olivine (Fo92), plagioclase (An86), clinopyroxene (Mg# = 82) and magnetite (Xulvö = 0.13). Experimental melts generally reproduce observed compositional trends among Arenal samples. Small differences between experimental melts and natural rocks can be explained by open-system processes. At low pressure (200 MPa), the mineral assemblage as well as the mineral compositions of the natural basalt were reproduced at 1,000 °C and high water activity. The residual melt at these conditions is basaltic andesitic (55 wt% SiO2) with 5 wt% H2O. The evolution to more evolved magmas observed at Arenal occurred under fluid-saturated conditions but variable fluid compositions. At 1,000 °C and 200 MPa, a decrease of water content by approximately 1 wt% induces significant changes of the mineral assemblage from olivine + clinopyroxene + plagioclase (5 wt% H2O in the melt) to clinopyroxene + plagioclase + orthopyroxene (4 wt% H2O in the melt). Both assemblages are observed in crystal-rich basalt (15 vol%) and basaltic andesites. Experimental data indicate that the lack of orthopyroxene

  4. The Mantle and Basalt-Crust Interaction Below the Mount Taylor Volcanic Field, New Mexico

    Science.gov (United States)

    Schrader, Christian M.; Crumpler, Larry S.; Schmidt, Marick E.

    2010-01-01

    The Mount Taylor Volcanic Field (MTVF) lies on the Jemez Lineament on the southeastern margin of the Colorado Plateau. The field is centered on the Mt. Taylor composite volcano and includes Mesa Chivato to the NE and Grants Ridge to the WSW. MTVF magmatism spans approximately 3.8-1.5 Ma (K-Ar). Magmas are dominantly alkaline with mafic compositions ranging from basanite to hy-basalt and felsic compositions ranging from ne-trachyte to rhyolite. We are investigating the state of the mantle and the spatial and temporal variation in basalt-crustal interaction below the MTVF by examining mantle xenoliths and basalts in the context of new mapping and future Ar-Ar dating. The earliest dated magmatism in the field is a basanite flow south of Mt. Taylor. Mantle xenolith-bearing alkali basalts and basanites occur on Mesa Chivato and in the region of Mt. Taylor, though most basalts are peripheral to the main cone. Xenolith-bearing magmatism persists at least into the early stages of conebuilding. Preliminary examination of the mantle xenolith suite suggests it is dominantly lherzolitic but contains likely examples of both melt-depleted (harzburgitic) and melt-enriched (clinopyroxenitic) mantle. There are aphyric and crystal-poor hawaiites, some of which are hy-normative, on and near Mt. Taylor, but many of the more evolved MTVF basalts show evidence of complex histories. Mt. Taylor basalts higher in the cone-building sequence contain >40% zoned plagioclase pheno- and megacrysts. Other basalts peripheral to Mt. Taylor and at Grants Ridge contain clinopyroxene and plagioclase megacrysts and cumulate-textured xenoliths, suggesting they interacted with lower crustal cumulates. Among the questions we are addressing: What was the chemical and thermal state of the mantle recorded by the basaltic suites and xenoliths and how did it change with time? Are multiple parental basalts (Si-saturated vs. undersaturated) represented and, if so, what changes in the mantle or in the tectonic

  5. A brief comparison of lava flows from the Deccan Volcanic Province and the Columbia-Oregon Plateau Flood Basalts: Implications for models of flood basalt emplacement

    Indian Academy of Sciences (India)

    Ninad Bondre; Raymond A Duraiswami; Gauri Dole

    2004-12-01

    The nature and style of emplacement of Continental Flood Basalt (CFB) lava flows has been a atter of great interest as well as considerable controversy in the recent past. However, even a cursory review of published literature reveals that the Columbia River Basalt Group (CRBG) and Hawaiian volcanoes provide most of the data relevant to this topic. It is interesting to note, however, that the CRBG lava flows and their palaeotopographic control is atypical of other CFB provinces in the world. In this paper, we first present a short overview of important studies pertaining to the emplacement of flood basalt flows. We then briefly review the morphology of lava flows from the Deccan Volcanic Province (DVP) and the Columbia-Oregon Plateau flood basalts. The review underscores the existence of significant variations in lava flow morphology between different provinces, and even within the same province. It is quite likely that there were more than one way of emplacing the voluminous and extensive CFB lava flows. We argue that the establishment of general models of emplacement must be based on a comprehensive documentation of lava flow morphology from all CFB provinces.

  6. Alkali basalts and enclosed ultramafic xenoliths near Ushuaia, Tierra Del Fuego, Argentina.

    Science.gov (United States)

    Acevedo, Rogelio Daniel

    2016-01-01

    At the southernmost part of Tierra del Fuego a few outcrops and erratic boulders of alkali basaltic rocks with ultramafic enclaves have been studied. Alkali basalt plugs or pipes hitherto identified are scarce, and host rocks are constituted by slates that belong to Mesozoic deposition. The petrography, texture and composition of the basalt and xenoliths were investigated by petrographic microscope and electron microprobe analysis. Xenocrysts of amphibole and alkali feldspar, phenocrysts of nepheline, olivine, spinel, phlogopite and Fe-Ti minerals (10 %) and a diversity of xenoliths, mainly lherzolitic, pyroxenite and wehrlitic nodules (15 %), but also from metamorphic rocks provenance, are contained in the basalt groundmass (75 %). This finer-grained material is made up of laths or needles of plagioclase, pyroxene, opaque minerals, apatite and glass, with intersertal, hyalopilitic and pilotaxitic. Locally, rock has an even granoblastic texture. Former amygdules are filled by analcite, zeolites, sodalite and calcite. The normative classification, based on nepheline content, conclude that this rock is an alkali basalt. The chemical classification, considering immobile elements as Zr/TiO2 versus Nb/Y indicate an alkali basalt too and plots over the TAS diagram fall in the foidite (Na-rich or nephelinite) and basanite fields. The REE patterns are fractionated (La/Yb primitive mantle normalized is approximately 30). The K-Ar isotopic technique on individual macrocrysts gave ages of 146 ± 5 Ma (amphibole) and 127 ± 4 Ma (alkali feldspar); and K-Ar whole rock datum reported 8.3 ± 0.3 Ma. Nevertheless, fertile samples show geochemical features typical of deep derived material thus, based on the position in the actual tectonic setting, indicate that the basalt is older than its isotopic age.

  7. Movement of coliform bacteria and nutrients in ground water flowing through basalt and sand aquifers.

    Science.gov (United States)

    Entry, J A; Farmer, N

    2001-01-01

    Large-scale deposition of animal manure can result in contamination of surface and ground water and in potential transfer of disease-causing enteric bacteria to animals or humans. We measured total coliform bacteria (TC), fecal coliform bacteria (FC), NO3, NH4, total P, and PO4 in ground water flowing from basalt and sand aquifers, in wells into basalt and sand aquifers, in irrigation water, and in river water. Samples were collected monthly for 1 yr. Total coliform and FC numbers were always higher in irrigation water than in ground water, indicating that soil and sediment filtered most of these bacteria before they entered the aquifers. Total coliform and FC numbers in ground water were generally higher in the faster flowing basalt aquifer than in the sand aquifer, indicating that the slower flow and finer grain size may filter more TC and FC bacteria from water. At least one coliform bacterium/100 mL of water was found in ground water from both basalt and sand aquifers, indicating that ground water pumped from these aquifers is not necessarily safe for human consumption according to the American Public Health Association and the USEPA. The NO3 concentrations were usually higher in water flowing from the sand aquifer than in water flowing from the basalt aquifer or in perched water tables in the basalt aquifer. The PO4 concentrations were usually higher in water flowing from the basalt aquifer than in water flowing from the sand aquifer. The main concern is fecal contamination of these aquifers and health consequences that may arise from human consumption.

  8. Interactions between basalts and oil source rocks in rift basins: CO2 generation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Basalts interbedded with oil source rocks are discovered frequently in rift basins of eastern China, where CO2 is found in reservoirs around or within basalts, for example in the Binnan reservoir of the Dongying Depression. In the reservoirs, CO2 with heavy carbon isotopic composition (δ13C>-10‰ PDB) is in most cases accounts for 40% of the total gas reserve, and is believed to have resulted from degassing of basaltic magma from the mantle. In their investigations of the Binnan reservoir, the authors suggested that the CO2 would result from interactions between the source rocks and basalts. As the source rocks around basalts are rich in carbonate minerals, volcanic minerals, transition metals and organic matter, during their burial history some of the transition metals were catalyzed on the thermal degradation of organic matter into hydrocarbons and on the decomposition of carbonate minerals into CO2, which was reproduced in thermal simulations of the source rocks with the transition metals (Ni and Co). This kind of CO2 accounts for 55%-85% of the total gas reserve generated in the process of thermal simulation, and its δ13C values range from -11‰- -7.2‰ PDB, which are very similar to those of CO2 found in the Binnan reservoir. The co-generation of CO2 and hydrocarbon gases makes it possible their accumulation together in one trap. In other words, if the CO2 resulted directly from degassing of basaltic magma or was derived from the mantle, it could not be accumulated with hydrocarbon gases because it came into the basin much earlier than hydrocarbon generation and much earlier than trap formation. Therefore, the source rocks around basalts generated hydrocarbons and CO2 simultaneously through catalysis of Co and Ni transition metals, which is useful for the explanation of co-accumulation of hydrocarbon gases and CO2 in rift basins in eastern China.

  9. Electrical Properties of Expanded Graphite Intercalation Compounds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The intercalation compounds of CuCl2 were synthesized with expanded graphite, whose magnitude of the electrical conductivity is about 103S.cm-1. Their electrical conductivity is 3~6 times as high as that of the expanded graphite, and about 10 times as high as that of GIC made of the non-expanded graphite. The microanalysis results of chemical compounds by X-ray energy spectrum scanning of TEM testified that the atomic ratio of chloride and cupric is nonstoichoimetric. The multivalence and exchange of electrovalence of the cupric ion was confirmed by the XPS-ESCA. Vacancy of chlorine anion increases the concentration of charge carrier.The special stage structure, made of graphite and chloride, produces a weak chemical bond belt and provides a carrier space in the direction of GIC layer. These factors develop the electrical properties.

  10. Analog model for an expanding universe

    CERN Document Server

    Weinfurtner, S E C

    2004-01-01

    Over the last few years numerous papers concerning analog models for gravity have been published. It was shown that the dynamical equation of several systems (e.g. Bose-Einstein condensates with a sink or a vortex) have the same wave equation as light in a curved-space (e.g. black holes). In the last few months several papers were released which deal with simulations of the universe. In this article the de-Sitter universe will be compared with a freely expanding three-dimensional spherical Bose-Einstein condensate. Initially the condensate is in a harmonic trap, which suddenly will be switched off. At the same time a small perturbation will be injected in the center of the condensate cloud. The motion of the perturbation in the expanding condensate will be discussed, and after some transformations the similarity to an expanding universe will be shown.

  11. Bank Directors’ Perceptions of Expanded Auditor's Reports

    DEFF Research Database (Denmark)

    Boolaky, Pran Krishansing; Quick, Reiner

    2016-01-01

    of expanded audit reports, namely information on the assurance level, materiality levels and key audit matters (KAM), on bank director perceptions of the quality of the financial statements, the audit and the audit report, as well as on their credit approval decisions. We conduct an experiment involving......Subsequent to the financial crisis, standard setters developed suggestions for enhancing the audit function, in order to increase financial stability. One related idea is to expand the audit report disclosed to the public, to ensure that it is fit for purpose. This study investigates the impact...... a sample of 105 bank directors and use ANCOVA to determine the predictors of bank director perceptions and decisions. Our findings suggest that disclosing the assurance level has a significantly positive impact. In contrast, we cannot demonstrate a material effect of expanding the audit report to include...

  12. Statistical factor analysis technique for characterizing basalt through interpreting nuclear and electrical well logging data (case study from Southern Syria).

    Science.gov (United States)

    Asfahani, Jamal

    2014-02-01

    Factor analysis technique is proposed in this research for interpreting the combination of nuclear well logging, including natural gamma ray, density and neutron-porosity, and the electrical well logging of long and short normal, in order to characterize the large extended basaltic areas in southern Syria. Kodana well logging data are used for testing and applying the proposed technique. The four resulting score logs enable to establish the lithological score cross-section of the studied well. The established cross-section clearly shows the distribution and the identification of four kinds of basalt which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The factor analysis technique is successfully applied on the Kodana well logging data in southern Syria, and can be used efficiently when several wells and huge well logging data with high number of variables are required to be interpreted.

  13. Basalt identification by interpreting nuclear and electrical well logging measurements using fuzzy technique (case study from southern Syria).

    Science.gov (United States)

    Asfahani, J; Abdul Ghani, B; Ahmad, Z

    2015-11-01

    Fuzzy analysis technique is proposed in this research for interpreting the combination of nuclear and electrical well logging data, which include natural gamma ray, density and neutron-porosity, while the electrical well logging include long and short normal. The main objective of this work is to describe, characterize and establish the lithology of the large extended basaltic areas in southern Syria. Kodana well logging measurements have been used and interpreted for testing and applying the proposed technique. The established lithological cross section shows the distribution and the identification of four kinds of basalt, which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The fuzzy analysis technique is successfully applied on the Kodana well logging data, and can be therefore utilized as a powerful tool for interpreting huge well logging data with higher number of variables required for lithological estimations.

  14. Bound systems in an expanding universe

    CERN Document Server

    Baker, G A

    2000-01-01

    The Schwarzchild solution insertion in an expanding universe, the so-called "Swiss cheese model," is shown to possess an extrinsic curvature miss-match. One consequence is that some trajectories are discontinuous functions of their initial conditions. An alternate metric is proposed which goes smoothly between the Schwarzchild exterior solution and the Friedmann-Lemaitre, expanding universe metric. It is further shown that the effects of the expansion on planetary motions in the solar system are too small to be currently observed for this alternate metric.

  15. Radiation damping in closed expanding universes

    Science.gov (United States)

    Bernui, Armando

    The dynamics of a coupled model (harmonic oscillator-relativistic scalar field) in Conformal Robertson-Walker (k = +1) spacetimes is investigated. The exact radiation-reaction equation of the source-including the retarded radiation terms due to the closed space geometry - is obtained and analyzed. A suitable family of Lyapunov functions is constructed to show that, if the spacetime expands monotonely, then the source's energy damps. A numerical simulation of this equation for expanding Universes, with and without Future Event Horizon, is performed.

  16. Wankel engines as steam expanders: design considerations

    Energy Technology Data Exchange (ETDEWEB)

    Badr, O.; Naik, S.; O' Callaghan, P.W.; Probert, S.D. (Cranfield Inst. of Tech., Bedford (GB). Dept. of Applied Energy)

    1991-01-01

    Rotary Wankel engines offer several advantages compared with turbines and other positive-displacement machines as the expansion devices in low-power-output Rankine-cycle systems. So a Wankel expander was selected as the most appropriate device for a steam Rankine-engine, operating principally as a mini combined heat-and-power unit, providing a mechanical output of 5-20 kW. A computer-aided-design technique for selecting the optimal geometry and location of the ports of the expander is described: the computer programs are available from the authors. Lubrication and possible material combinations are also discussed. (author).

  17. Experimental Evidence for Polybaric Intracrustal Differentiation of Primitive Arc Basalt beneath St. Vincent, Lesser Antilles

    Science.gov (United States)

    Blundy, Jon; Melekhova, Lena; Robertson, Richard

    2014-05-01

    We present experimental phase equilibria for a primitive, high-Mg basalt from St. Vincent, Lesser Antilles. Experimental details were presented in Melekhova et al (Nature Geosci, 2013); the objective here is to compare experimental phase compositions to those of erupted lavas and cumulates from St. Vincent. Starting material with 4.5 wt% H2O is multiply-saturated with a lherzolite assemblage at 1.3 GPa and 1180 ° C, consistent with mantle wedge derivation. Experimental glasses from our study, in addition to those of Pichavant et al (GCA, 2002) and Pichavant & Macdonald (CMP 2007) on a similar high-Mg basalt, encompass a compositional range from high-magnesian basalt to dacite, with a systematic dependence on H2O content, temperature and pressure. We are able to match the glasses from individual experiments to different lava types, so as to constrain the differentiation depths at which these magmas could be generated from a high-Mg parent, as follows: Composition wt% H2OP (GPa) T (° C) High-Mg basalt 3.9-4.8 1.45-1.751180-1200 Low-Mg basalt 2.3-4.5 1.0-1.3 1065-1150 High alumina basalt 3.0-4.5 0.4 1050-1080 Basaltic andesite 0.6-4.5 0.7-1.0 1050-1130 Andesite 0.6 1.0 1060-1080 The fact that St. Vincent andesites (and some basaltic andesites) appear to derive from a low-H2O (0.6 wt%) parent suggest that they are products of partial melting of older, high-Mg gabbroic rocks, as 0.6 wt% H2O is approximately the amount that can be stored in amphibole-bearing gabbros. The higher H2O contents of parents for the other lava compositions is consistent with derivation by crystallization of basalts with H2O contents that accord with those of olivine-hosted melt inclusions from St. Vincent (Bouvier et al, J Petrol, 2008). The generation of evolved melts both by basalt crystallization and gabbro melting is consistent with the hot zone concept of Annen et al (J Petrol, 2006) wherein repeated intrusion of mantle-derived basalt simultaneously crystallize by cooling and melt

  18. Low H2O/Ce in Icelandic basalts as evidence for crustal recycling

    Science.gov (United States)

    Neave, David; Shorttle, Oliver; Hartley, Margaret; Maclennan, John

    2016-04-01

    The generation of new crust at mid-ocean ridges is balanced by the subduction of partially hydrothermally altered basaltic material back into the mantle. This subducted material may then be recycled and returned via mantle plumes to the Earth's surface at hot spots. Long-identified isotopic and trace element signatures of oceanic crust recycling in ocean island basalts (OIBs) have been recently supplemented by evidence of major element, i.e. lithological, heterogeneity in the melting region. For example, combined major and trace element systematics from Iceland suggest that the mantle source contains at least 5% recycled basalt. Observations of high water (H2O) contents in subglacially quenched basalts from Iceland have previously been attributed to the incorporation of wet recycled material into the mantle source. However, when combined with trace element analyses, recent volatile analyses from the Laki-Grímsvötn and Bárðarbunga-Veiðivötn systems in the Eastern Volcanic Zone (EVZ) of Iceland suggest that the underlying mantle is comparatively depleted in H2O for its degree of major and trace element enrichment. Correlations between H2O and cerium (Ce) within individual mid-ocean ridge basalt (MORB) suites reveal that these elements partition similarly prior to H2O degassing at low pressures; H2O/Ce remains constant during melting and fractionation, and hence reflects the average H2O/Ce of the melting region. MORBs from the Mid-Atlantic Ridge south of Iceland have a mean H2O/Ce value of 304±48 at a mean La/Yb of 2.1±1.5. In contrast, basalts from the EVZ have a lower mean H2O/Ce of 180±20 at a higher mean La/Yb of 3.1±0.5. Thus, despite coming from an enriched section of the Mid-Atlantic ridge in terms of trace element content, basalts from the EVZ have the lowest H2O/Ce values known from the ridge, and are hence comparatively depleted in H2O. Given that H2O/Ce from un-degassed basalts is considered to represent mantle source values, we suggest that low H

  19. Controls on volcanism at intraplate basaltic volcanic fields

    Science.gov (United States)

    van den Hove, Jackson C.; Van Otterloo, Jozua; Betts, Peter G.; Ailleres, Laurent; Cas, Ray A. F.

    2017-02-01

    A broad range of controlling mechanisms is described for intraplate basaltic volcanic fields (IBVFs) in the literature. These correspond with those relating to shallow tectonic processes and to deep mantle plumes. Accurate measurement of the physical parameters of intraplate volcanism is fundamental to gain an understanding of the controlling factors that influence the scale and location of a specific IBVF. Detailed volume and geochronology data are required for this; however, these are not available for many IBVFs. In this study the primary controls on magma genesis and transportation are established for the Pliocene-Recent Newer Volcanics Province (NVP) of south-eastern Australia as a case-study for one of such IBVF. The NVP is a large and spatio-temporally complex IBVF that has been described as either being related to a deep mantle plume, or upper mantle and crustal processes. We use innovative high resolution aeromagnetic and 3D modelling analysis, constrained by well-log data, to calculate its dimensions, volume and long-term eruptive flux. Our estimates suggest volcanic deposits cover an area of 23,100 ± 530 km2 and have a preserved dense rock equivalent of erupted volcanics of least 680 km3, and may have been as large as 900 km3. The long-term mean eruptive flux of the NVP is estimated between 0.15 and 0.20 km3/ka, which is relatively high compared with other IBVFs. Our comparison with other IBVFs shows eruptive fluxes vary up to two orders of magnitude within individual fields. Most examples where a range of eruptive flux is available for an IBVF show a correlation between eruptive flux and the rate of local tectonic processes, suggesting tectonic control. Limited age dating of the NVP has been used to suggest there were pulses in its eruptive flux, which are not resolvable using current data. These changes in eruptive flux are not directly relatable to the rate of any interpreted tectonic driver such as edge-driven convection. However, the NVP and other

  20. Heterogeneous source components of intraplate basalts from NE China induced by the ongoing Pacific slab subduction

    Science.gov (United States)

    Chen, Huan; Xia, Qun-Ke; Ingrin, Jannick; Deloule, Etienne; Bi, Yao

    2017-02-01

    The subduction of oceanic slabs is widely accepted to be a main reason for chemical heterogeneities in the mantle. However, determining the contributions of slabs in areas that have experienced multiple subduction events is often difficult due to possible overlapping imprints. Understanding the temporal and spatial variations of source components for widespread intraplate small volume basalts in eastern China may be a basis for investigating the influence of the subducted Pacific slab, which has long been postulated but never confirmed. For this purpose, we investigated the Chaihe-aershan volcanic field (including more than 35 small-volume Quaternary basaltic volcanoes) in NE China and measured the oxygen isotopes and water content of clinopyroxene (cpx) phenocrysts using secondary ion mass spectrometry (SIMS) and Fourier transform infrared spectroscopy (FTIR), respectively. The water content of magma was then estimated based on the partition coefficient of H2O between cpx and the basaltic melt. The δ18O of cpx phenocrysts (4.28‰ to 8.57‰) and H2O content of magmas (0.19 wt.%-2.70 wt.%) show large variations, reflecting the compositional heterogeneity of the mantle source. The δ18O values and H2O content within individual samples also display considerable variation, suggesting the mixing of magmas and that the magma mixing occurred shortly before the eruption. The relation between the δ18O values of cpx phenocrysts and the H2O/Ce ratio, Ba/Th ratio and Eu anomaly of whole rocks demonstrates the contributions of three components to the mantle source (hydrothermally altered upper oceanic crust and marine sediments, altered lower gabbroic oceanic crust, and ambient mantle). The proportions of these three components have varied widely over time (∼1.37 Ma to ∼0.25 Ma). The Pacific slab is constantly subducted under eastern Asia and continuously transports recycled materials to the deep mantle. The temporal heterogeneity of the source components may be caused

  1. The Effect of Shock on the Amorphous Component in Altered Basalt

    Science.gov (United States)

    Eckley, S. A.; Wright, S. P.; Rampe, E. B.; Niles, P. B.

    2017-01-01

    Investigation of the geochemical and mineralogical composition of the Martian surface provides insight into the geologic history of the predominantly basaltic crust. The Chemistry and Mineralogy (CheMin) instrument onboard the Curiosity rover has returned the first X-Ray diffraction data from the Martian surface. However, large proportions (27 +/- 14 with some estimates as high as 50 weight percentage) of an amorphous component have been reported. As a remedy to this problem, mass balance equations using geochemistry, volatile chemistry, and mineralogy have been employed to constrain the geochemistry of the amorphous component. However, "the nature and number of amorphous phases that constitute the amorphous component is not unequivocally known". Multiple hypotheses have been proposed to explain the origin of this amorphous component: Allophane (Al2O); Basaltic glass (Volcanic and impact); Palagonite (Altered basaltic glass); Hisingerite (Fe (sup 3 plus)-bearing phyllosilicate); S/Cl-rich component (sulfates and/or akaganeite); Nanophase ferric oxide component (npOx). Establishing a multi-phase amorphous component from a basaltic precursor that has undergone physical and chemical weathering within geochemical constraints is of paramount importance to better understand the composition of a large portion of the Martian surface (up to 50 weight percentage). Shocked basalts from Lonar Crater in India are valuable analogs for the Martian surface because it is a well-preserved impact crater in a basaltic target. Having undergone pre- and post-shock aqueous alteration, these rocks provide crucial data regarding the effect of shock on the amorphous component in altered basalt. By conducting mass balance equations similar to what has been performed for Gale crater materials, we attempt to calculate the geochemistry of the amorphous component in altered basalts ranging from unshocked to Class 5 (Table 1). This has the potential to reveal the nature and origin (i.e. primary

  2. Mantle source provinces beneath the Northwestern USA delimited by helium isotopes in young basalts

    Science.gov (United States)

    Graham, D. W.; Reid, M. R.; Jordan, B. T.; Grunder, A. L.; Leeman, W. P.; Lupton, J. E.

    2009-11-01

    We report new He, Nd and Sr isotope results for basalts from the northwestern United States. The new 3He/ 4He results for olivine phenocrysts in basalts from the eastern Snake River Plain (SRP), the Owyhee Plateau (OP) and the Oregon High Lava Plains (HLP), together with published He isotope data for Yellowstone and the Cascades volcanic arc, delineate distinct mantle sources for each of these sub-provinces. All basalts from the eastern SRP (8 Quaternary localities plus 1 Miocene locality) have 3He/ 4He ratios higher than observed in normal mid-ocean ridge basalts, but overlapping with ranges observed in hotspot-related oceanic islands. For a lateral distance of some 400 km along the SRP, 3He/ 4He ranges from ~ 11 RA in the west to > 19 RA adjacent to Yellowstone. Such high ratios have not been observed elsewhere in the western U.S., and are consistent with the presence of a mantle plume. The lateral gradient in 3He/ 4He suggests that the proportion of plume-derived He decreases westward, but this interpretation is complicated by possible addition of crustal helium during open-system crystal fractionation in some SRP basaltic magmas. Although crustal contamination may modulate 3He/ 4He in basalts along the SRP, the effect is not strong and it does not obscure the elevated 3He/ 4He mantle source signature. In contrast, young basalts from the HLP and the OP have 3He/ 4He values of 8.8-9.3 RA, within the range for mid-ocean ridge basalts; these data reflect a shallow asthenospheric source with no discernible influence from the Yellowstone hotspot. Basalts from Newberry volcano have slightly lower 3He/ 4He (7.6-8.3 RA), within the range for other Cascades arc lavas (7.0-8.4 RA). Three alternative explanations are possible for the origin of the high 3He/ 4He signature along the SRP: (1) multi-component mixing of (a) magmas and/or CO 2-rich fluids derived from plume mantle having high 3He/ 4He, (b) continental lithosphere having low 3He/ 4He, and (c) shallow

  3. Geochemical characteristics and petrogenesis of Mesozoic basalts from the North China Craton: A case study in Fuxin, Liaoning Province

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Occurrence of Cretaceous basalts in Fuxin County, Liaoning Province provides us an opportunity to understand Mesozoic mantle processes beneath the northern margin of the North China Craton (NNCC). Fuxin Jianguo basalts occur as volcanic channel phases with well-developed columnar jointings and contain few spinel lherzolite and pyroxenite xenoliths. They are poor in silica and rich in alkalis, Ti and Al, belonging to alkaline basalts. In trace element compositions, Jianguo basalts are moderately enriched in LREE and LILE, but not depleted in HFSE. They have low Sr and high Nd and Pb isotopic ratios. These geochemical characteristics suggest that Jianguo basalts originated from the depleted asthenosphere, representing an undifferentiated and uncontaminated primitive magma. Presence of these basalts indicates that the lithosphere beneath the region had thickness less than 65 km at the time of basalt eruption and was mainly composed of fertile pargasite-bearing spinel lherzolite and plagioclase pyroxenite. The voluminous basaltic-andesitic magmatism during the early Jurassic-late Cretaceous time indicates that the commencement and accomplishment of lithosphere thinning in the NNCC was much earlier than that in the southern margin, since the mafic-intermediate volcanism only occurred at the Cretaceous time in the southern margin and the basalts with an asthenosphere isotopic signature at the Tertiary. This shows that highly spatial and temporal heterogeneity existed in the Mesozoic lithosphere evolution.

  4. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 7. Baseline rock properties-basalt

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    This volume, Y/OWI/TM-36/7 Baseline Rock Properties--Basalt, is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-36'' which supplements a ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-44.'' The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This report contains an evaluation of the results of a literature survey to define the rock mass properties of a generic basalt, which could be considered as a geological medium for storing radioactive waste. The general formation and structure of basaltic rocks is described. This is followed by specific descriptions and rock property data for the Dresser Basalt, the Amchitka Island Basalt, the Nevada Test Site Basalt and the Columbia River Group Basalt. Engineering judgment has been used to derive the rock mass properties of a typical basalt from the relevant intact rock property data and the geological information pertaining to structural defects, such as joints and faults.

  5. Numerical modeling of time-lapse monitoring of CO2 sequestration in a layered basalt reservoir

    Science.gov (United States)

    Khatiwada, M.; Van Wijk, K.; Clement, W.P.; Haney, M.

    2008-01-01

    As part of preparations in plans by The Big Sky Carbon Sequestration Partnership (BSCSP) to inject CO2 in layered basalt, we numerically investigate seismic methods as a noninvasive monitoring technique. Basalt seems to have geochemical advantages as a reservoir for CO2 storage (CO2 mineralizes quite rapidly while exposed to basalt), but poses a considerable challenge in term of seismic monitoring: strong scattering from the layering of the basalt complicates surface seismic imaging. We perform numerical tests using the Spectral Element Method (SEM) to identify possibilities and limitations of seismic monitoring of CO2 sequestration in a basalt reservoir. While surface seismic is unlikely to detect small physical changes in the reservoir due to the injection of CO2, the results from Vertical Seismic Profiling (VSP) simulations are encouraging. As a perturbation, we make a 5%; change in wave velocity, which produces significant changes in VSP images of pre-injection and post-injection conditions. Finally, we perform an analysis using Coda Wave Interferometry (CWI), to quantify these changes in the reservoir properties due to CO2 injection.

  6. Preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.L.; O' Rourke, J.E.; Allirot, D.; O' Connor, K.

    1980-09-01

    This report presents results of a study leading to preconceptual designs for plugging boreholes, shafts, and tunnels to a nuclear waste repository in basalt. Beginning design criteria include a list of preferred plug materials and plugging machines that were selected to suit the environmental conditions, and depths, diameters, and orientations of the accesses to a nuclear waste repository in the Columbia River basalts located in eastern Washington State. The environmental conditions are described. The fiscal year 1979-1980 Task II work is presented in two parts: preliminary testing of materials for plugging of man-made accesses to a repository in basalt (described in a separate report); and preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt (described in this report). To fulfill the scope of the Task II work, Woodward-Clyde Consultants (WCC) was requested to: provide preconceptual systems for plugging boreholes, tunnels, and shafts in basalt; describe preconceptual borehole plugging equipment for placing the selected materials in man-made accesses; utilize the quality assurance program, program plan and schedule, and work plans previously developed for Task II; and prepare a preliminary report.

  7. Characteristics of platinum-group elements in basalts from spreading axis of Mariana Trough

    Institute of Scientific and Technical Information of China (English)

    CAO Zhimin; ZHENG Jianbin; ZHOU Meifu; AN Wei; QI Liang

    2007-01-01

    Total platinum-group elements (PGEs) abundances in basalts from the spreading axis of Mariana Trough ranged from 0.418 × 10-9 to 1.022 × 10-9, and primitive mantle-normalized PGE patterns are of positive slope showing the relative enrichment of PPGE (platinum, palladium, rhodium) and gold relative to IPGE. Compared with other mantle-originated rocks, these basalts have lower PGE contents and wider ranges of primitive mantle-normalized ratios of palladium content to iridium one, palladium content to platinum one and palladium content to gold one exhibiting relative platinum and iridium depletion. Characteristics of PGE patterns indicated that the studied Mariana Trough basalts originated from low partial melting, and the MORB mantle beneath the spreading center had been contaminated by the arc-island mantle. In the aspect of trace elements, Mariana Trough basalts showed the enrichment of LILE, lead and LREE, indicating that they had been influenced by subduction compositions. All these demonstrated that Mariana Trough basalts are products of partial melting from a mixed mantle ( the contamination of MORB mantle by arc-island mantle).

  8. A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair.

    Science.gov (United States)

    Chen, Xi; Li, Yan; Gu, Ning

    2010-08-01

    A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

  9. Evidence for pressure-release melting beneath magmatic arcs from basalt at Galunggung, Indonesia

    Science.gov (United States)

    Sisson, T.W.; Bronto, S.

    1998-01-01

    The melting of peridotite in the mantle wedge above subduction zones is generally believed to involve hydrous fluids derived from the subducting slab. But if mantle peridotite is upwelling within the wedge, melting due to pressure release could also contribute to magma production. Here we present measurements of the volatile content of primitive magmas from Galunggung volcano in the Indonesian are which indicate that these magmas were derived from the pressure-release melting of hot mantle peridotite. The samples that we have analysed consist of mafic glass inclusions in high-magnesium basalts. The inclusions contain uniformly low H2O concentrations (0.21-0.38 wt%), yet relatively high levels of CO2 (up to 750 p.p.m.) indicating that the low H2O concentrations are primary and not due to degassing of the magma. Results from previous anhydrous melting experiments on a chemically similar Aleutian basalts indicate that the Galunggung high-magnesium basalts were last in equilibrium with peridotite at ~1,320 ??C and 1.2 GPa. These high temperatures at shallow sub-crustal levels (about 300-600 ??C hotter than predicted by geodynamic models), combined with the production of nearly H2O- free basaltic melts, provide strong evidence that pressure-release melting due to upwelling in the sub-are mantle has taken place. Regional low- potassium and low-H2O (ref. 5) basalts found in the Cascade are indicate that such upwelling-induced melting can be widespread.

  10. The Composition of the Fluids in Alkali Basalts and Mantle-Derived Xenoliths in Eastern China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Minjie; WANG Xianbin; LIU Gang; LI Liwu

    2001-01-01

    The components of the fluids released from alkali basalts and mantle-derived Iherzolite xenoliths in eastern China have been determined by the vacuum pyrolysis-mass spectrometric (MS) method in the present study. The results show that mantle-derived lherzolites formed in fluids composed mainly of reducing gases such as H2 and CO, and their fluid composition is characterized by a higher H2 content and a lower total content of volatiles. The fluids in alkali basalts are composed mainly of oxidizing gases, such as CO2 an SO2 and characterized by higher contents of SO2 and volatiles,implying that the extraneous oxidized fluids which are composed mainly of SO2 mixed with primary alkali basaltic magmas during their formation and evolution. The fluid compositions of alkali basalts and Iherzolite xenoliths show high nonhomogeneity in the upper mantle source region and difference in alkali basaltic magma evolution in different districts. It can be deduced that the region with higher PH2 could exist in the upper mantle beneath eastern China.

  11. Expanded austenite, crystallography and residual stress

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Hummelshøj, Thomas Strabo; Somers, Marcel A. J.

    2010-01-01

    compositions and (b) unravelling of the contributions of stress-depth and composition-depth profiles in expanded austenite layers are summarised and discussed. It is shown through simulation of line profiles that the combined effects of composition gradients, stress gradients and stacking fault gradients can...

  12. Expanded austenite; crystallography and residual stress

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Hummelshøj, Thomas Strabo; Somers, Marcel A. J.

    2009-01-01

    The identity of expanded austenite as developing during low temperature nitriding and/or carburizing of austenitic stainless steel has been under debate since the very first observation of this phase. In the present article recent results obtained with i) homogeneous samples of various uniform...

  13. Properties of extruded expandable breadfruit products

    Science.gov (United States)

    Dried breadfruit was extruded with a twin screw extruder to develop a value-added expanded fruit product. This research studied the effects of barrel temperature (120-160°C), moisture content (13-25%), feeding rate (13-25 kg/h) and screw speed (115-175rpm) on physicochemical properties (bulk densit...

  14. Expanding the applicability of Heallth Technology Assessments

    DEFF Research Database (Denmark)

    Draborg, Eva; Hansen, Helle Ploug

    2012-01-01

    The objective of the presentation is to expand the foundations of input into policy decision making relying on health technology assessments (HTA). HTAs are primarily based on systematic reviews (SR) and thereby mostly on randomized controlled trials (RCT). RCTs can be distinguished on a continuu...

  15. Expanding the collaboration between CERN and Pakistan

    CERN Multimedia

    2002-01-01

    Parvez Butt, chairman of the Pakistan Atomic Energy Commission, and CERN Director General, Luciano Maiani, signed a letter of intent last week to expand collaboration. Through an agreement which should be formalized within a few months, Pakistan would make a substantial contribution to the LHC and its detectors, coordinated by the Pakistani National Centre of Physics.

  16. Expanding Your Horizons Conference in Geneva

    CERN Multimedia

    Chromek-Burckhart, Doris

    2011-01-01

    CERN and its experiments participated in Expanding Your Horizons (EYH) in Science and Mathematics conference in Geneva on 12th November. EYH nurture girls' interest in science and math courses to encourage them to consider careers in science, technology, engineering, and math.

  17. Responsible implementation of expanded carrier screening

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-01-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines. PMID:26980105

  18. Expanding CTE Opportunities through Blended Learning

    Science.gov (United States)

    McKinstry, Elizabeth

    2012-01-01

    The global economy, 21st century skills, knowledge society, college and career readiness, digital and project-based learning are all common terms to educators who are expanding their learning environments beyond the classroom to meet the needs of all students. It is common knowledge that the rapid technological advances of this century have…

  19. Expanding the Focus of Career Assessment.

    Science.gov (United States)

    Lock, Jared D.; Hogan, Robert

    2000-01-01

    Issues affecting career assessment include change in the focus and definition of career, emphasis on quality of work life, expansion of career paths, increased amount of career information available on the Internet, and questionable quality of online assessment. An expanded model of career assessment now includes technical fit, personal fit,…

  20. Responsible implementation of expanded carrier screening.

    Science.gov (United States)

    Henneman, Lidewij; Borry, Pascal; Chokoshvili, Davit; Cornel, Martina C; van El, Carla G; Forzano, Francesca; Hall, Alison; Howard, Heidi C; Janssens, Sandra; Kayserili, Hülya; Lakeman, Phillis; Lucassen, Anneke; Metcalfe, Sylvia A; Vidmar, Lovro; de Wert, Guido; Dondorp, Wybo J; Peterlin, Borut

    2016-06-01

    This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.

  1. Heat expanded starch-based compositions.

    Science.gov (United States)

    Glenn, Gregory M; Klamczynski, Artur K; Holtman, Kevin M; Shey, Justin; Chiou, Bor-Sen; Berrios, Jose; Wood, Delilah; Orts, William J; Imam, Syed H

    2007-05-16

    A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period.

  2. Ordinary chondritic micrometeorites from the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Rudraswami, N.G.; Babu, E.V.S.S.K.; VijayaKumar, T.

    Extraterrestrial particulate materials on the Earth can originate in the form of collisional debris from the asteroid belt, cometary material, or as meteoroid ablation spherules. Signatures that link them to their parent bodies become obliterated...

  3. Cometary micrometeorites and input of prebiotic compounds

    OpenAIRE

    2014-01-01

    The apparition of life on the early Earth was probably favored by inputs of extraterrestrial matter brought by carbonaceous chondrite-like objects or cometary material. Interplanetary dust collected nowadays on Earth is related to carbonaceous chondrites and to cometary material. They contain in particular at least a few percent of organic matter, organic compounds (amino-acids, PAHs,…), hydrous silicates, and could have largely contributed to the budget of prebiotic matter on Earth, about 4 ...

  4. Modeling of the Sedimentary Interbedded Basalt Stratigraphy for the Idaho National Laboratory Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suzette Payne

    2006-04-01

    This report summarizes how the effects of the sedimentary interbedded basalt stratigraphy were modeled in the probabilistic seismic hazard analysis (PSHA) of the Idaho National Laboratory (INL). Drill holes indicate the bedrock beneath INL facilities is composed of about 1.1 km of alternating layers of basalt rock and loosely consolidated sediments. Alternating layers of hard rock and “soft” loose sediments tend to attenuate seismic energy greater than uniform rock due to scattering and damping. The INL PSHA incorporated the effects of the sedimentary interbedded basalt stratigraphy by developing site-specific shear (S) wave velocity profiles. The profiles were used in the PSHA to model the near-surface site response by developing site-specific stochastic attenuation relationships.

  5. Modeling of the Sedimentary Interbedded Basalt Stratigraphy for the Idaho National Laboratory Probabilistic Seismic Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suzette Payne

    2007-08-01

    This report summarizes how the effects of the sedimentary interbedded basalt stratigraphy were modeled in the probabilistic seismic hazard analysis (PSHA) of the Idaho National Laboratory (INL). Drill holes indicate the bedrock beneath INL facilities is composed of about 1.1 km of alternating layers of basalt rock and loosely consolidated sediments. Alternating layers of hard rock and “soft” loose sediments tend to attenuate seismic energy greater than uniform rock due to scattering and damping. The INL PSHA incorporated the effects of the sedimentary interbedded basalt stratigraphy by developing site-specific shear (S) wave velocity profiles. The profiles were used in the PSHA to model the near-surface site response by developing site-specific stochastic attenuation relationships.

  6. Preliminary K/Ar geochronology of the Crater Basalt volcanic field (CBVF, northern Patagonia

    Directory of Open Access Journals (Sweden)

    Z. Pécskay

    2007-03-01

    Full Text Available The Crater Basalt volcanic field is one of the Quaternary intraplate basaltic fields in northern Patagonia. A systematic geological, volcanological and geochronological study of CBVF indicates a multistage history of eruptions of basaltic volcanoes. K/Ar dating, using whole rock samples shows that the measured analytical ages are fully consistent with the available stratigraphic control. The radiometric ages fall into three distinct, internally consistent age groups, which give evidence that there were at least three major episodes of volcanic activity, at about 1.0 Ma, 0.6 Ma and 0.3 Ma ago. The age differences appear to be just significant, even although less than 10 % radiogenic argon was found in the isotope analysis of whole rock samples.

  7. Two—Dimensional Mathematical Model and Numerical Simulation Describing the Melting Process of Cylindrical Basalt Bed

    Institute of Scientific and Technical Information of China (English)

    YanQuanying; ShangDeku; 等

    1999-01-01

    A two-dimensional mathematical model was built to describe the melting process of cylindrical basalt particle bed in a crucible.The melting processes with respect to the factors of thermal boundary conditions and particle sizes of basalt were simulated by using the numerical method (FDM).The governing equations were discretized in tridiagonal matrix form and were solved by using the tridiagonal matrix algorithm (TDMA) as well as the alternative direction implicit(ADI) solver.The temperature distribution,the moving law of the two dimensional phase-change boundaries the thermal current distribution were given through the numerical simulation.The results provided a theoretical basis for deciding heating procedure,for evaluating power import and controlling furnace temperature and for predicting basalt melting states etc.In the experiment,an electrical furnace was designed based on the computations.It has been proved that the simulation results are reasonably coincident with the experimental data.

  8. Study of inflammatory responses to crocidolite and basalt wool in the rat lung.

    Science.gov (United States)

    Adamis, Z; Kerényi, T; Honma, K; Jäckel, M; Tátrai, E; Ungváry, G

    2001-03-09

    The subacute effects of crocidolite and basalt wool dusts were studied by nmeans of biochemical, morphological. and histological methods 1 and .3 mo after intrabronchial instillation. The cell count, protein and phospholipid contents, and lactate dehydrogenase (LDH) activity were determined in the bronchoalveolar lavage (BAL). Both types of fibers induced a prolonged inflammatory reaction in the lung. All the parameters studied in the experimental groups were more markedly elevated after 3 mo. Relative to the control, the protein and LDH values were increased three- to fivefold, the phospholipid content twofold, and the number of free cells in the BAL exceeded the control level up to ninefold. The inflammatory responses to crocidolite and basalt wool in the lung did not differ significantly. In spite of this, basalt wool is recoinmended as an asbestos substitute, as the use of this man-nade fiber may result in a significantly lower release of dust than that from crocidolite.

  9. 40Ar/39Ar dates from the West Siberian Basin: Siberian flood basalt province doubled.

    Science.gov (United States)

    Reichow, Marc K; Saunders, Andrew D; White, Rosalind V; Pringle, Malcolm S; Al'Mukhamedov, Alexander I; Medvedev, Alexander I; Kirda, Nikolay P

    2002-06-07

    Widespread basaltic volcanism occurred in the region of the West Siberian Basin in central Russia during Permo-Triassic times. New 40Ar/39Ar age determinations on plagioclase grains from deep boreholes in the basin reveal that the basalts were erupted 249.4 +/- 0.5 million years ago. This is synchronous with the bulk of the Siberian Traps, erupted further east on the Siberian Platform. The age and geochemical data confirm that the West Siberian Basin basalts are part of the Siberian Traps and at least double the confirmed area of the volcanic province as a whole. The larger area of volcanism strengthens the link between the volcanism and the end-Permian mass extinction.

  10. A study on the crushing behavior of basalt fiber reinforced composite structures

    Science.gov (United States)

    Pandian, A.; Veerasimman, A. P.; Vairavan, M.; Francisco, C.; Sultan, M. T. H.

    2016-10-01

    The crushing behavior and energy absorption capacity of basalt fiber reinforced hollow square structure composites are studied under axial compression. Using the hand layup technique, basalt fiber reinforced composites were fabricated using general purpose (GP) polyester resin with the help of wooden square shaped mould of varying height (100 mm, 150 mm and 200 mm). For comparison, similar specimens of glass fiber reinforced polymer composites were also fabricated and tested. Axial compression load is applied over the top end of the specimen with cross head speed as 2 mm/min using Universal Testing Machine (UTM). From the experimental results, the load-deformation characteristics of both glass fiber and basalt fiber composites were investigated. Crashworthiness and mode of collapse for the composites were determined from load-deformation curve, and they were then compared to each other in terms of their crushing behaviors.

  11. Preparation of Basalt Incorporated Polyethylene Composite with Enhanced Mechanical Properties for Various Applications

    Directory of Open Access Journals (Sweden)

    Bredikhin Pavel

    2017-01-01

    Full Text Available The present article showed the possibility of increasing the complex of mechanical properties of polyolefins with dispersed mineral fillers obtained by fine grinding of basalt rocks via ball mill processing. The composites based on dispersed basalt, which were derived from Samara rock mass (Russia with rare earth elements containing, were obtained by extrusion combining the binder and filler, followed by preparation injection-molded test samples. The study of mechanical properties of materials developed showed the possibility of a significant increase in strength characteristics of different types of polyethylene: the breaking stress at static bending for HDPE can be increasing more than 60% and the impact strength by more than 4 times. In addition the incorporation of the dispersed basalt also enhanced the thermal properties of the composites (the oxygen index of HDPE increases from 19 to 25%.

  12. 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.

  13. [Dynamic studies of the leukocyte phagocytic activity after exposure of rats to asbestos and basalt fibers].

    Science.gov (United States)

    Hurbánková, M

    1993-05-01

    The paper presents the results of the dynamic one-year follow-up of the phagocytic activity of Wistar-rats peripheral blood leukocytes following intraperitoneal administration of asbestos and basalt fibres (Man-Made Mineral Fibres--MMMF). We investigated the phagocytic activity of leukocytes in peripheral blood following intraperitoneal administration of asbestos and basalt fibres to rats 2, 24, 48 h as well as 1, 2, 4, 8 weeks and 6 and 12 months after dosing. We investigated the time dependent of the changes of relative granulocytes count, percentage of phagocytizing cells from leukocytes, percentage of phagocytizing granulocytes and percentage of phagocytizing monocytes. The results of our experiment showed that asbestos and basalt fibres differed in their effects on the parameters studied. Granulocyte count as well as the phagocytic activity of leukocytes during the one-year dynamic follow-up in both dust--exposed groups of animals were found to change in two phases, characterised by the initial stimulation of the acute phase (I), followed by the suppression of the parameters in the chronic phase (II). Exposure to asbestos and basalt fibres led, in phase II, to impairment of the phagocytic activity of granulocytes. Asbestos fibres at the same time significantly decreased also the phagocytic activity of monocytes. Exposure to basalt fibres did not affect the phagocytic activity of monocytes in phase II. It follows from the results of the experiment, that the monocytic component of leukocytes probably plays an important role in the development of diseases caused by exposure to fibrous dusts and basalt fibres have smaller biological effects compared with asbestos fibres.

  14. Where is basalt in river sediments, and why does it matter?

    Science.gov (United States)

    Garçon, Marion; Chauvel, Catherine

    2014-12-01

    Weathering, erosion and mineralogical sorting processes modify the chemical and isotopic compositions of sediments relative to those of their source rocks. The way and extent to which those processes affect the geochemistry of sediments is however not yet fully understood. Here, we report trace element data as well as Nd, Hf and Pb isotopic compositions of sediments sampled at different water depths in the Ganges, Yamuna and Chambal Rivers draining the Deccan Traps basalts and the crystalline and sedimentary rocks from the Himalayan mountain range and the northern Indian shield. Isotopic differences between surface and bed sediments sampled at the same location reach 6 εNd and about 15 εHf units, suggesting that suspended loads and bedloads do not carry similar provenance information. Such differences are explained by the combined effects of differential erosion and mineralogical sorting processes during fluvial transport. Materials eroded from basalts are preferentially transported in suspension near the river surface while materials eroded from more crystalline precursors are transported near the bottom of the river. This depth-dependent provenance within the river channel leads to an overrepresentation of basaltic materials in fine-grained suspended loads that are finally delivered into the ocean and become part of the oceanic terrigenous clays. By contrast, the proportion of basaltic materials in coarser sediments such as bedloads or turbidites is underestimated. Our results have important consequences on the use of Nd, Hf and Pb isotopic compositions of sediments as provenance proxies because they indicate that all grain-size fractions must be taken into account to properly trace source compositions. They also suggest that upper continental crust estimates derived from fine-grained sediments, such as suspended loads, may be biased towards basaltic compositions if basaltic outcrops are present in the drainage area.

  15. Thermobarometry for spinel lherzolite xenoliths in alkali basalts

    Science.gov (United States)

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

    2016-04-01

    geothermobarometry based on reactions with large and distinct volume changes, is necessary. Specification of mineral domains and their components representing the thermal state of the mantle just before xenolith extraction is one of the major tasks for the establishment of reliable geothermobarometry for spinel lherzolite xenoliths. Systematic variations of such mineralogical information among xenoliths transported by a single volcanic eruption guarantees proper estimation of a mantle geotherm. For the development of such geobarometry, it is important to choose appropriate xenolith locality, where previous studies provide enough information and where many xenolith samples are available for extending a range of derivation depth. Spinel lherzolite xenoliths in alkali basalts from Bou Ibalhatene maars in the Middle Atlas in Morocco are suitable study target. Geochemical, geochronological, petrological, and rheological aspects of the spinel lherzolite xenoliths have been studied (Raffone et al. 2009; El Messbahi et al., 2015; Witting et al., 2010; El Azzouzi et al., 2010), which show that they represent fragments of the lithospheric mantle formed and modified since 1.7Ga before their extraction from Miocene to recent. We have pinpointed portions of minerals in the xenolith samples and their components representing condition just before their entrapment in magmas, on which appropriate geothermobarometers are applied and detected ~0.5GPa pressure difference (1.5-2.0GPa) for ~100°C variation in temperatures (950-1050°C).

  16. Local Environmental Effects from Deposition of Basaltic Tephra

    Science.gov (United States)

    Ort, M. H.; Sheppard, P. R.; Anderson, K. C.; Elson, M. D.

    2012-12-01

    Basaltic tephra is produced by scoria cones and by composite and stratovolcanoes, which may cover 1000s-10,000's km2 with tephra to depths greater than 1 cm. This tephra changes the abiotic and biotic environment. The thickness of the tephra affects whether plants can send their seeds and roots to the soil underneath or grow through the tephra to reach the surface. More than 20 cm of tephra greatly inhibits most plant growth, as shown by agricultural experiments and observations of natural landscapes. At Sunset Crater in northern Arizona, incipient soil formation (after ~925 years) consists of eolian grains having sifted down to a depth of 10-20 cm, forming a finer grained layer that retains water. Plant roots concentrate at this level, helping to trap more fine grains and adding organic material to the layer. This then provides a more hospitable environment for further plant growth and the development of soil ecosystems. Fresh tephra, especially if coarse, allows water to pass through it to the underlying soil, reducing runoff, and slows subsequent evaporation. At Sunset Crater, increased water infiltration led to better plant growth in semiarid grasslands and forest and possibly to new springs and increased surface water. At Parícutin in Michoacán, México, flooding caused by abundant rain that saturated the tephra led to stream shifts and erosion. Tephra has available ions on the surface of grains and the volcanic glass may be easily altered. This, combined with increased water retention in the soil, can lead to changes in soil and groundwater chemistry underlying the tephra. Adhering sulfur, as well as HCl- and HNO3-rich rainfall, can lower pH in the water, dissolving soil ions as mineralogical phase changes occur in response to the lower pH. At three scoria cones (Sunset Crater, Paricutin, and Cinder Cone, which is in northeast California), tree-ring chemistry reflects changes in the soil-water composition. P and S increase for a few years to decades after

  17. Petrology and chemistry of the Huntzinger flow, Columbia River basalt, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Ward, A.W. Jr.

    1976-11-01

    Drill core samples of basalts of the Columbia River Group from the Hanford Reservation reveal a spotted, diabasic flow of up to 60 meters in thickness. These samples and those from the flow outcropping at Wahatis Peak (Saddle Mountains, Washington) were examined in detail to document intraflow textural, mineralogical, and chemical variations, which are of importance in basalt flow correlations. Analyses were by atomic absorption, instrumental neutron activation, electron microprobe, natural gamma well logging, K-Ar age dating, X-ray fluorescence, field (portable) magnetometer, and petrographic microscope.

  18. Sr Isotopic Evidence on the Spilitic Degradation of the Deccan Basalt

    Indian Academy of Sciences (India)

    K V Subbarao

    2000-03-01

    Similar Sr isotopic ratios (∼0.7055) for the tholeiite-spilite flow unit and the associated mineral phases, of Bombay (Deccan Traps) provide a direct evidence for the spilitic degradation of tholeiite. In contrast, a dramatic increase in the rare earth elements (REE) from basalt to spilite is rather puzzling as rare earths are considered to be relatively immobile. The geochemistry thus suggests that the process of spilitization is due to the reaction with a complex fluid having identical Sr-isotopic composition as that of the basaltic magma - thereby masking the details of the mixing process.

  19. Basalt waste isolation project. Quarterly report, October 1, 1980-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.

    1981-02-01

    In September 1977, the National Waste Terminal Storage Program was restructured to support investigations of two US DOE sites - Hanford and Nevada. The Basalt Waste Isolation Project within Rockwell Hanford Operations has been chartered with the responsibility of conducting these investigations. The overall Basalt Waste Isolation Project is divided into the following principal work areas: systems integration, geosciences, hydrology, engineered barriers, near-surface test facility, engineering testing, and repository studies. Summaries of major accomplishments for each of these areas are reported in this document.

  20. A New Oxygen Barometer for Solar System Basaltic Glasses Based on Vanadium Valence

    Science.gov (United States)

    Karner, J. M.; Sutton, S. R.; Papike, S. R.; Delaney, J. S.; Shearer, C. K.; Newville, M.; Eng, P.; Rivers, M.; Dyar, M. D.

    2004-01-01

    The determination of oxidation conditions for basaltic magmas derived by the melting of planetary mantles is critical to our understanding of the nature and evolution of planetary interiors. Yet, these determinations are compromised in terrestrial and especially extraterrestrial basalts by our analytical and computational methods for estimating oxygen fugacity (fO2). For example, mineralogical barometers (1, 2) can be reduced in effectiveness by subsolidus re-equilibration of mineral assemblages, inversion of mineralogical data to melt characteristics, and deviations of the natural mineral compositions from ideal thermodynamic parameters.

  1. From shifting silt to solid stone: the manufacture of synthetic basalt in ancient mesopotamia

    Science.gov (United States)

    Stone; Lindsley; Pigott; Harbottle; Ford

    1998-06-26

    Slabs and fragments of gray-black vesicular "rock," superficially resembling natural basalt but distinctive in chemistry and mineralogy, were excavated at the second-millennium B.C. Mesopotamian city of Mashkan-shapir, about 80 kilometers south of Baghdad, Iraq. Most of this material appears to have been deliberately manufactured by the melting and slow cooling of local alluvial silts. The high temperatures (about 1200 degreesC) required and the large volume of material processed indicate an industry in which lithic materials were manufactured ("synthetic basalt") for grinding grain and construction.

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

    Science.gov (United States)

    Nerilli, Francesca; Vairo, Giuseppe

    2016-06-01

    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.

  3. Olivine Major and Trace Element Compositions in Southern Payenia Basalts, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina; Portnyagin, Maxim; Hoernle, Kaj;

    2015-01-01

    Olivine major and trace element compositions from 12 basalts from the southern Payenia volcanic province in Argentina have been analyzed by electron microprobe and laser ablation inductively coupled plasma mass spectrometry. The olivines have high Fe/Mn and low Ca/Fe and many fall at the end...... by subduction-zone fluids and/or melts. The increasing contributions from the pyroxene-rich source in the southern Payenia basalts are correlated with an increasing Fe-enrichment, which caused the olivines to have lower forsterite contents at a given Ni content. Al-in-olivine crystallization temperatures...

  4. Evidence for a basalt-free surface on Mercury and implications for internal heat.

    Science.gov (United States)

    Jeanloz, R; Mitchell, D L; Sprague, A L; de Pater, I

    1995-06-01

    Microwave and mid-infrared observations reveal that Mercury's surface contains less FeO + TiO2 and at least as much feldspar as the lunar highlands. The results are compatible with the high albedo (brightness) of Mercury's surface at visible wavelengths in suggesting a rock and soil composition that is devoid of basalt, the primary differentiate of terrestrial mantles. The occurrence of a basalt-free, highly differentiated crust is in accord with recent models of the planet's thermal evolution and suggests that Mercury has retained a hot interior as a result of a combination of inefficient mantle convection and minimal volcanic heat loss.

  5. Quantitative mineralogical characterization of lunar high-Ti mare basalts and soils for oxygen production

    Science.gov (United States)

    Chambers, J. G.; Taylor, L. A.; Patchen, A.; McKay, D. S.

    1995-07-01

    Efficient lunar resource utilization requires accurate and quantitative evaluation of mineral and glass abundances, distribution, and extraction feasibility, especially for ilmenite. With this in mind, true modal analyses were performed on high-Ti mare basalts and soils with X ray/backscattered electron signal digital-imaging techniques, and these data indicate that (1) ilmenite concentrations are similar for basalts and immature-submature soils with similar TiO2 content; (2) ilmenite liberation of crushed mare basalts and immature-submature mare soils are comparable (i.e., both contain similar amounts of free ilmenite); and (3) because of impact melting and agglutination of primary minerals, mature mare soils contain less ilmenite (both free and attached). Modal analyses of magnetic separates of high-Ti mare basalts and soils show that (1) ilmenite was concentrated by a factor of >=3.3 and (2) soil ilmenite was concentrated to factors of 1.7-2.3. The lower soil ilmenite separation efficiency is attributed to Fe°-bearing agglutinitic glass and amorphous rinds adhered to soil particles. Mass yields of magnetically generated feedstocks were generally less than 5 wt.% in most cases. Calculation of oxygen yield (as released by hydrogen gas reduction of ilmenite) show that (1) beneficiated basalt will provide the most oxygen (8-10%), because of higher ilmenite concentration; (2) reduction of raw immature-submature mare soils and basalts will produce similar amounts of lunar liquid oxygen (LLOX) (2.1-3.1%) and (3) raw Fe-rich pyroclastic soil, 74220, will provide more oxygen (5.4%) than beneficiated high-Ti mare soils and half that of beneficiated high-Ti mare basalts. High-Ti mare soils are attractive resources for lunar liquid oxygen (LLOX) production because of their unconsolidated nature, high ilmenite abundance, and widespread occurrence. Energy-intensive excavation and comminution likely prohibits the basalt mining during early lunar occupation. Orange soils are

  6. Degassing and contamination of noble gases in Mid-Atlantic Ridge basalts

    OpenAIRE

    Burnard, P.; Harrison, D.; Turner, G.; Nesbitt, R

    2003-01-01

    New He, Ne, Ar and CO2 stepped-crushing data from the Mid-Atlantic Ridge show that contamination of basalts by atmospheric noble gases involves three or more components: unfractionated air, fractionated air with high 36Ar/22Ne (45) and fractionated air with low 36Ar/22Ne (5). In addition, the magmatic noble gases trapped in these basaltic glasses are variably fractionated such that 4He/40Ar* (where the asterisk indicates corrected for atmospheric contamination based on all 36Ar being atmosphe...

  7. Geochemistry of Paraná-Etendeka basalts from Misiones, Argentina: Some new insights into the petrogenesis of high-Ti continental flood basalts

    Science.gov (United States)

    Rämö, O. Tapani; Heikkilä, Pasi A.; Pulkkinen, Arto H.

    2016-04-01

    The Early Cretaceous (˜135-131 Ma) Paraná-Etendeka continental flood basalts, preserved in bulk in the Paraná basin of southern Brazil and vicinity, have been divided into low-Ti and high-Ti types that govern the southern and northern halves of the basin, respectively. We have examined a new sample set from the southern margin of the northern high-Ti segment of Paraná basalts in Misiones, northeastern Argentina. These basalts are strongly to moderately enriched in TiO2 (2-4 wt.%), have relatively high Ti/Y (300-500), low MgO (3.5-6.5 wt.%), and high Fe (FeO(tot) 12-14 wt.%) and belong to the Pitanga and Paranapanema magma types of Peate et al. (1992). Nd and Sr isotope compositions are quite unvarying with ɛNd (at 133 Ma) values of -4.6 to -3.6 and initial 87Sr/86Sr of 0.7054-0.7059 and show no variation with fractionation. Compared to high-Ti lavas in the central and northern parts of the Paraná high-Ti basalt segment, the lavas from Misiones are similar to those in the northeastern magin of the basin but less radiogenic in initial Nd isotope composition than those in the central part. This variation probably reflects mixed EM1-EM2 source components in the sublithospheric mantle. A polybaric melt model of a sublithospheric mantle source at the garnet lherzolite-spinel lherzolite transition is compatible with the observed Ti budget of the Pitanga and Paranapanema lavas, regardless of the Nd isotope composition of their purported source.

  8. Origin of arc-like continental basalts: Implications for deep-Earth fluid cycling and tectonic discrimination

    Science.gov (United States)

    Wang, Xuan-Ce; Wilde, Simon A.; Xu, Bei; Pang, Chong-Jin

    2016-09-01

    Continental basalts generally display enrichment of fluid-mobile elements and depletion of high-field-strength elements, similar to those that evolved in the subduction environment, but different from oceanic basalts. Based on the continental flood basalt database for six large igneous provinces, together with rift-related basalt data from the Basin and Range Province, this study aimed to test the validity of geochemical tectonic discrimination diagrams in distinguishing arc-like intra-continental basalts from arc basalts and to further investigate the role of deep-Earth water cycling in producing arc-like signatures in large-scale intra-continental basalts. Our evaluation shows that arc-like intra-continental basalts can be distinguished from arc basalts by integrating the following factors: (1) the FeO, MgO, and Al2O3 concentrations of the primary melt; (2) Tisbnd V, Zrsbnd Zr/Y, Zrsbnd Ti, and Ti/Vsbnd Zr/Smsbnd Sr/Nd discrimination diagrams; (3) the coexistence of arc-like and OIB-like subtype basalts within the same province; (4) primitive mantle-normalized trace element distribution patterns. The similarity of enrichment in fluid-mobile elements (Ba, Rb, Sr, U, and K) between arc-like and true arc basalts suggests the importance of water flux melting in producing arc-like signatures in continental basalts. Experimentally determined liquid lines of descent (LLD) imply high magma water concentrations for continental flood basalts (CFBs) and the Basin and Range basalts. Furthermore, estimates based on the Al2O3-LLD method indicates 4.0-5.0 wt% pre-eruptive magma H2O concentration for CFBs and the Basin and Range basalts. The tight relationships between H2O/Ce and Ba/La, Ba/Nb and Rb/Nb based on global arc basalt data were further used to estimate the primary H2O concentrations. With the exception of the Emeishan CFBs (mainly containing 4.0-5.6 wt% H2O), all other CFBs investigated have similar estimated primary H2O contents, with values ranging from 1.0 to 2

  9. Expanding advanced civilizations in the universe

    CERN Document Server

    Gros, C

    2005-01-01

    The 1950 lunch-table remark by Enrico Fermi `Where is everybody' has started intensive scientific and philosophical discussions about what we call nowadays the `Fermi paradox': If there had been ever a single advanced civilization in the cosmological history of our galaxy, dedicated to expansion, it would have had plenty of time to colonize the entire galaxy via exponential growth. No evidence of present or past alien visits to earth are known to us, leading to the standard conclusion that no advanced expanding civilization has ever existed in the milky-way \\cite{Webb}. This conclusion rest fundamentally on the ad-hoc assumption, that any alien civilizations dedicated to expansion at one time would remain dedicated to expansions forever. Considering our limited knowledge about alien civilizations we need however to relax this basic assumption. Here we show that a substantial and stable population of expanding advanced civilization might consequently exist in our galaxy.

  10. Parameter estimation for an expanding universe

    Directory of Open Access Journals (Sweden)

    Jieci Wang

    2015-03-01

    Full Text Available We study the parameter estimation for excitations of Dirac fields in the expanding Robertson–Walker universe. We employ quantum metrology techniques to demonstrate the possibility for high precision estimation for the volume rate of the expanding universe. We show that the optimal precision of the estimation depends sensitively on the dimensionless mass m˜ and dimensionless momentum k˜ of the Dirac particles. The optimal precision for the ratio estimation peaks at some finite dimensionless mass m˜ and momentum k˜. We find that the precision of the estimation can be improved by choosing the probe state as an eigenvector of the hamiltonian. This occurs because the largest quantum Fisher information is obtained by performing projective measurements implemented by the projectors onto the eigenvectors of specific probe states.

  11. Carbohydrate plasma expanders for passive tumor targeting

    DEFF Research Database (Denmark)

    Hoffmann, Stefan; Caysa, Henrike; Kuntsche, Judith

    2013-01-01

    The objective of this study was to investigate the suitability of carbohydrate plasma volume expanders as a novel polymer platform for tumor targeting. Many synthetic polymers have already been synthesized for targeted tumor therapy, but potential advantages of these carbohydrates include...... inexpensive synthesis, constant availability, a good safety profile, biodegradability and the long clinical use as plasma expanders. Three polymers have been tested for cytotoxicity and cytokine activation in cell cultures and conjugated with a near-infrared fluorescent dye: hydroxyethyl starches (HES 200 k......Da and HES 450 kDa) and dextran (DEX 500 kDa). Particle size and molecular weight distribution were determined by asymmetric flow field-flow fractionation (AF4). The biodistribution was investigated non-invasively in nude mice using multispectral optical imaging. The most promising polymer conjugate...

  12. Hubble, Hubble's law and the expanding universe

    OpenAIRE

    Bagla, J. S.

    2009-01-01

    Hubble's name is associated closely with the idea of an expanding universe as he discovered the relation between the recession velocity and distances of galaxies. Hubble also did a lot of pioneering work on the distribution of galaxies in the universe. In this article we take a look at Hubble's law and discuss how it relates with models of the universe. We also give a historical perspective of the discoveries that led to the Hubble's law.

  13. Inextendibility of expanding cosmological models with symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Dafermos, Mihalis [University of Cambridge, Department of Pure Mathematics and Mathematical Statistics, Wilberforce Road, Cambridge CB3 0WB (United Kingdom); Rendall, Alan D [Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Am Muehlenberg 1, D-14476 Golm (Germany)

    2005-12-07

    A new criterion for inextendibility of expanding cosmological models with symmetry is presented. It is applied to derive a number of new results and to simplify the proofs of existing ones. In particular, it shows that the solutions of the Einstein-Vlasov system with T{sup 2} symmetry, including the vacuum solutions, are inextendible in the future. The technique introduced adds a qualitatively new element to the available tool-kit for studying strong cosmic censorship. (letter to the editor)

  14. Expander Graphs in Pure and Applied Mathematics

    OpenAIRE

    Lubotzky, Alexander

    2011-01-01

    Expander graphs are highly connected sparse finite graphs. They play an important role in computer science as basic building blocks for network constructions, error correcting codes, algorithms and more. In recent years they have started to play an increasing role also in pure mathematics: number theory, group theory, geometry and more. This expository article describes their constructions and various applications in pure and applied mathematics.

  15. GWDC Expands High-End Market Share

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ It is a decision of great significance for GWDC to expand high-end market share in order to realize its transformation of development strategy and improve its development quality. As an important step of GWDC to explore high-end market, Oman PDO Project marks the first time that the Chinese petroleum engineering service team cooperates with the transnational petroleum corporations ranking first three in the world.

  16. Cosmic strings in an expanding spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Stein-Schabes, J.A.; Burd, A.B.

    1988-03-15

    We study string solutions in an expanding Friedmann-Robertson-Walker (FRW) spacetime. The back reaction of the string on the spacetime has been ignored so that the background stays Friedmannian throughout the evolution. By numerically integrating the field equations in both radiation- and matter-dominated eras, we discover some new oscillatory solutions. The possible damping of these oscillations is discussed. For late times the solution becomes identical to the static one.

  17. Strings, Fivebranes and an Expanding Universe

    OpenAIRE

    2002-01-01

    It was recently shown that velocity-dependent forces between parallel fundamental strings moving apart in a $D-$dimensional spacetime implied an accelerating expanding universe in $D-1$-dimensional space-time. Exact solutions were obtained for the early time expansion in $D=5,6$. Here we show that this result also holds for fundamental strings in the background of a fivebrane, and argue that the feature of an accelerating universe would hold for more general $p$-brane-seeded models.

  18. Measurements of an expanding surface flashover plasma

    Energy Technology Data Exchange (ETDEWEB)

    Harris, J. R., E-mail: john.harris@colostate.edu [Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2014-05-21

    A better understanding of vacuum surface flashover and the plasma produced by it is of importance for electron and ion sources, as well as advanced accelerators and other vacuum electronic devices. This article describes time-of-flight and biased-probe measurements made on the expanding plasma generated from a vacuum surface flashover discharge. The plasma expanded at velocities of 1.2–6.5 cm/μs, and had typical densities of 10{sup 10}–10{sup 12} cm{sup −3}. The expansion velocity of the plasma leading edge often exhibited a sharp increase at distances of about 50 mm from the discharge site. Comparison with biased-probe data suggests that, under most conditions, the plasma leading edge was dominated by negative ions, with the apparent increase in velocity being due to fast H{sup −} overtaking slower, heavier ions. In some cases, biased-probe data also showed abrupt discontinuities in the plasma energy distribution co-located with large changes in the intercepted plasma current, suggesting the presence of a shock in the leading edge of the expanding plasma.

  19. Optical cavity resonator in an expanding universe

    CERN Document Server

    Kopeikin, Sergei

    2014-01-01

    We study evolution of frequency of a standing electromagnetic (EM) wave in a resonant optical cavity placed to the expanding manifold described by the Robertson-Walker metric. One builds a local coordinate system in which spacetime is locally Minkowskian. However, due to the conformal nature of the Robertson-Walker metric the conventional transformation to the local inertial coordinates introduces ambiguity in the physical interpretation of the local time coordinate. Therefore, contrary to a common-sense expectation, a straightforward implementation of EEP alone does not allow us to decide whether atomic clocks ticks at the same rate as the clocks based on EM modes of a cavity. To resolve the ambiguity we analyzed the cavity rigidity and the oscillation of its EM modes in an expanding universe by employing the Maxwell equations. We found out that both the size of the cavity and the EM frequency experience an adiabatic drift in conformal coordinates as the universe expands. We set up the oscillation equation f...

  20. Lubricin in human breast tissue expander capsules.

    Science.gov (United States)

    Cheriyan, Thomas; Guo, Lifei; Orgill, Dennis P; Padera, Robert F; Schmid, Thomas M; Spector, Myron

    2012-10-01

    Capsular contraction is the most common complication of breast reconstruction surgery. While presence of the contractile protein alpha smooth muscle actin (α-SMA) is considered among the causes of capsular contraction, the exact etiology and pathophysiology is not fully understood. The objective of this study was to investigate the possible role of lubricin in capsular formation and contraction by determining the presence and distribution of the lubricating protein lubricin in human breast tissue expander capsules. Related aims were to evaluate select histopathologic features of the capsules, and the percentage of cells expressing α-SMA, which reflects the myofibroblast phenotype. Capsules from tissue expanders were obtained from eight patients. Lubricin, at the tissue-implant interface, in the extracellular matrix, and in cells, and α-SMA-containing cells were evaluated immunohistochemically. The notable finding was that lubricin was identified in all tissue expander capsules: as a discrete layer at the tissue-implant interface, extracellular, and intracellular. There was a greater amount of lubricin in the extracellular matrix in the intimal-subintimal zone when compared with the tissue away from the implant. Varying degrees of synovial metaplasia were seen at the tissue-implant interface. α-SMA-containing cells were also seen in all but one patient. The findings might help us better understand factors involved in capsule formation.

  1. Inverted porphyrins and expanded porphyrins: An overview

    Indian Academy of Sciences (India)

    S K Pushpan; S Venkatraman; V G Anand; J Sankar; H Rath; T K Chandrashekar

    2002-08-01

    Porphyrins and metallopophyrins have attracted the attention of chemists for the past 100 years or more owing to their widespread involvement in biology. More recently, synthetic porphyrins and porphyrin-like macrocycles have attracted the attention of researchers due to their diverse applications as sensitizers for photodynamic therapy, MRI contrasting agents, and complexing agents for larger metal ions and also for their anion binding abilities. The number of -electrons in the porphyrin ring can be increased either by increasing the number of conjugated double bonds between the pyrrole rings or by increasing the number of heterocyclic rings. Thus, 22 sapphyrins, 26 rubyrins, 30 heptaphyrins, 34 octaphyrins and higher cyclic polypyrrole analogues containing 40, 48, 64, 80 and 96 systems have recently been reported in the literature. These macrocycles show rich structural diversity where normal and different kinds of inverted structures have been identified. In this review, an attempt has been made to collect the literature of the inverted porphyrins and expanded porphyrins reported until December 2001. Since the meso aryl expanded porphyrins have tendency to form both inverted and non-inverted structures more emphasis has been given to meso aryl expanded porphyrins.

  2. Valence State Partitioning of Cr and V Between Pyroxene - Melt: Estimates of Oxygen Fugacity for Martian Basalt QUE 94201

    Science.gov (United States)

    Karner, J. M.; Papike, J. J.; Shearer, C. K.; McKay, G.; Le, L.; Burger, P.

    2007-01-01

    Several studies, using different oxybarometers, have suggested that the variation of fO2 in martian basalts spans about 3 log units from approx. IW-1 to IW+2. The relatively oxidized basalts (e.g., pyroxene-phyric Shergotty) are enriched in incompatible elements, while the relatively reduced basalts (e.g., olivine-phyric Y980459) are depleted in incompatible elements. A popular interpretation of the above observations is that the martian mantle contains two reservoirs; 1) oxidized and enriched, and 2) reduced and depleted. The basalts are thus thought to represent mixing between these two reservoirs. Recently, Shearer et al. determined the fO2 of primitive olivine-phyric basalt Y980459 to be IW+0.9 using the partitioning of V between olivine and melt. In applying this technique to other basalts, Shearer et al. concluded that the martian mantle shergottite source was depleted and varied only slightly in fO2 (IW to IW+1). Thus the more oxidized, enriched basalts had assimilated a crustal component on their path to the martian surface. In this study we attempt to address the above debate on martian mantle fO2 using the partitioning of Cr and V into pyroxene in pyroxene-phyric basalt QUE 94201.

  3. A Plagioclase Ultraphyric Basalt group in the Neogene flood basalt piles of eastern Iceland: Volcanic architecture and mode of emplacement

    Science.gov (United States)

    Oskarsson, B. V.; Riishuus, M. S.

    2013-12-01

    3D photogrammetry in conjunction with ground mapping was applied in order to assess the architecture of a Plagioclase Ultraphyric Basalt (PUB) group in eastern Iceland, namely the Grænavatn group. The ~10 Myr old group is exposed in steep glacially carved fjords and can be traced over 60 km along strike. Two feeder dikes have been found and show that the group erupted along the trend of the dike swarm associated with the Breiddalur central volcano. The group has 9--14 flows where thickest, and thins to about 3--4 flows up-dip to the east within the distance of 15-20 km from the source. We have estimated the volume of the group to exceed 40 km3. The flows have mixed architecture of simple and compound morphology. The flow lobes have thicknesses from 1--24 m and many reach lengths over 1000 m. The surface morphology varies from rubbly to scoriaceous, but is dominantly of pahoehoe style. The internal structure of the lava flows is well preserved and the flows display abundant vesicle cylinders. The modal percentage of An-rich plagioclase macrocrysts varies from 25--50 % and they are in the range of 5--30 mm. The aspect ratio of the group and the nature of the flows indicate fissure-fed eruptions. A thick flow found at the base of the group in various locations seems to record the largest eruption episode in the formation of the group. This phase is also the most abundant in macrocryst. An asymmetric buildup is seen in one location and may have characterized the general buildup of the group. The general morphology of the lava flows suggests low viscous behavior, at odds with the high crystal content. Petrographic observations and mineral chemistry shows that the plagioclase macrocrysts are very calcic (An80-85) and in disequilibrium with the groundmass and plagioclases therein (An50-70). Thus the apparent lava rheology and emplacement of the PUBs was likely achieved due to fast ascent of the magma through the crust and transfer of heat from the primitive macrocrysts

  4. Geochemical discrimination of the geotectonic environment of basaltic-andesitic volcanic rocks associated with the Laochang polymetallic ore deposit at Lancang, Yunnan

    Institute of Scientific and Technical Information of China (English)

    GAO Jianguo

    2006-01-01

    The Laochang polymetallic ore deposit at Lancang is one of the well known ancient ore deposits associated with volcanic rocks in the Sanjiang (Tri-river) region of Southwest China. Volcanic rocks are dominated by alkali basalt and trachyte basalt. There has long been a controversy on the environment of formation of basalts. Some scholars hold that the basalts were formed in a continental environment, some thought they were formed in an oceanic environment and others considered that the basalts were emplaced in a back-arc basin. This study focuses on the geochemical characteristics of the basalts on the basis of their major elements, REEs and trace elements. At the same time, strongly incompatible elements such as Ta, Th and Hf and their ratios were used to differentiate the geotectonic settings of basalts. The results showed that the basalts in the region studied were formed in a continental rift environment.

  5. Petrology, geochemistry, and age of low-Ti mare-basalt meteorite Northeast Africa 003-A: A possible member of the Apollo 15 mare basaltic suite

    Science.gov (United States)

    Haloda, Jakub; Týcová, Patricie; Korotev, Randy L.; Fernandes, Vera A.; Burgess, Ray; Thöni, Martin; Jelenc, Monika; Jakeš, Petr; Gabzdyl, Pavel; Košler, Jan

    2009-06-01

    Northeast Africa 003 (NEA 003) is a lunar meteorite found as a two paired stones (6 and 118 g) in Libya, 2000 and 2001. The main portion (˜75 vol%) of the 118 g meteorite, used for this study, (NEA 003-A) consists of mare-basalt and a smaller adjacent portion (˜25 vol%) is a basaltic breccia (NEA 003-B). NEA 003-A has a coarse-grained magmatic texture consisting mainly of olivine, pyroxene and plagioclase. The late-stage mineral association is composed mainly of elongated plagioclase, ilmenite, troilite, fayalite, Si-K-rich glass, apatite, and a rare SiO 2 phase. Other accessory minerals include ulvöspinel, chromite, and trace Fe-Ni metal. Olivine and pyroxene contain shock-induced fractures, and plagioclase is completely converted into maskelynite. The Fe/Mn values of the whole rock, olivines and pyroxenes, and the bulk-rock oxygen isotopic composition provide evidence for the lunar origin of NEA 003-A meteorite. This is further supported by the presence of Fe-Ni metal and the anhydrous mineral association. NEA 003-A is geochemically and petrographically distinct from previously described mare-basalt meteorites and is not paired with any of them. The petrography and major element composition of NEA 003-A is similar to the composition of low-Ti olivine mare basalts from Apollo 12 and olivine-normative basalts from Apollo 15. The NEA 003-A meteorite shows obvious geochemical similarities in trace elements contents with Apollo 15 olivine-normative basalts and could represent a yet unknown geochemically primitive member of the olivine-normative basalt series. The meteorite is depleted in rare earth elements (REE) and incompatible trace elements indicating a primitive character of the parental magma. The bulk-rock chemical composition demonstrates that the parent melt of NEA 003-A was not contaminated with KREEP components as a result of magma mixing or assimilation processes. Results of crystallization modelling and low minimum cooling rate estimates (˜0.07

  6. Calculation of water-bearing primary basalt and estimation of source mantle conditions beneath arcs: PRIMACALC2 model for WINDOWS

    Science.gov (United States)

    Kimura, Jun-Ichi; Ariskin, Alexey A.

    2014-04-01

    present a new method for estimating the composition of water-bearing primary arc basalt and its source mantle conditions. The PRIMACALC2 model uses a thermodynamic fractional crystallization model COMAGMAT3.72 and runs with an Excel macro to examine the mantle equilibrium and trace element calculations of a primary basalt. COMAGMAT3.72 calculates magma fractionation in 0-10 kb at various compositions, pressure, oxygen fugacity, and water content, but is only applicable for forward calculations. PRIMACALC2 first calculates the provisional composition of a primary basalt from an observed magma. The basalt composition is then calculated by COMAGMAT3.72 for crystallization. Differences in elemental concentrations between observed and the closest-match calculated magmas are then adjusted in the primary basalt. Further iteration continues until the calculated magma composition converges with the observed magma, resulting in the primary basalt composition. Once the fitting is satisfied, back calculations of trace elements are made using stepwise addition of fractionated minerals. Mantle equilibrium of the primary basalt is tested using the Fo-NiO relationship of olivine in equilibrium with the primary basalt, and thus with the source mantle. Source mantle pressure, temperature, and degree of melting are estimated using petrogenetic grids based on experimental data obtained in anhydrous systems. Mantle melting temperature in a hydrous system is computed by adjusting T with a parameterization for a water-bearing system. PRIMACALC2 can be used either in dry or water-bearing arc magmas and is also applicable to mid-ocean ridge basalts and nonalkalic ocean island basalts.

  7. Investigating the explosivity of shallow sub-aqueous basaltic eruptions

    Science.gov (United States)

    Murtagh, R.; White, J. D. L.

    2009-04-01

    Volcanic eruptions produce pyroclasts containing vesicles, clearly implying exsolution of volatiles from the magma has occurred. Our aim is to understand the textural characteristics of vesiculated clasts as a quantitative indicator of the eruptive behaviour of a volcano. Assessing water's role in volatile degassing and outgassing has been and is being well documented for terrestrial eruptions; the same cannot be said, however, for their shallow subaqueous counterparts. The eruptive behaviour of Surtseyan volcanoes, which include both subaqueous and subaerial phases (for example, the type-location Surtsey, Iceland in 1963) is under investigation here and for good reason. Volcanic eruptions during which water and basaltic magma come into contact appear to ignite violent eruptions of many of the small "monogenetic" volcanoes so abundant on Earth. A key problem remains that detailed conditions of water-magma interactions are not yet fully understood. Field samples obtained from exposed sequences deposited originally in a subaqueous environment allow for the necessary analysis of lapilli. With the aid of experimental data, mathematical modelling and terrestrial analogues the ambition is to unravel volatile degassing, ascent histories and fragmentation processes, allowing us ultimately to identify both the role water plays in the explosivity of shallow subaqueous eruptions, and the rise history of magma to the point of interaction. The first site, Pahvant Butte is located in southwest Utah, U.S. It is a well preserved tuff cone overlying a subaqueously deposited mound of glassy ash composed of sideromelane and tachylite. It was erupted under ~85m of water into Lake Bonneville approximately 15,300 years ago. Our focus is on samples collected from a well-bedded, broadly scoured coarse ash and lapilli lithofacies on the eastern flank of the edifice. Vesicularity indices span from 52.6% - 60.8%, with very broad vesicularity ranges, 20.6% - 81.0% for one extreme sample. The

  8. Mossbauer spectroscopy of magnetic minerals in basalt on Earth and Mars

    DEFF Research Database (Denmark)

    Gunnlaugsson, H. P.; Rasmussen, H.; Kristjansson, L.;

    2008-01-01

    Mossbauer spectroscopy of iron-titanium containing spinel phases is reviewed. New techniques are presented for determination of their composition using room-temperature Mossbauer spectroscopy. An example of thermal alteration processes is described. The speciality of olivine-containing basalt is ...

  9. 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.

    seamount shows more fractionated characters (Mg: 0.56-0.57) compared to the outer ridge flank lava of the VT area (Mg: 0.63-0.65). This study concludes that present basalts experienced low-pressure crystallization at a relatively shallow depth...

  10. Modeled Top of the Grande Ronde Basalt Geomodel Unit (grtop_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The grtop_f grid represents the modeled elevation of the top of the Grande Ronde Basalt geomodel unit at a 500 foot resolution. It is one grid of a geomodel that...

  11. Modeled Top of the Saddle Mountains Basalt Geomodel Unit (smtop_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The smtop_f grid represents the modeled elevation of the top of the Saddle Mountains Basalt geomodlel unit at a 500 foot resolution. It is one grid of a geomodel...

  12. Basalt Waste Isolation Project. Quarterly report, July 1, 1979-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.

    1979-10-01

    Progress in various areas of the Basalt Waste Isolation Project during the last quarter is reported. Systems integration, licensing, geologic activities, hydrology, borehole studies, geophysical logging, engineered barriers, test facilities, testing of canisters, and selection process for architect-engineer services for repository conceptual design are discussed. (DC)

  13. Processing and Characterization of Basalt Fiber Reinforced Ceramic Composites for High Temperature Applications Using Polymer Precursors

    Science.gov (United States)

    Cox, Sarah B.; Lui, Donovan; Gou, Jihua

    2014-01-01

    The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The two PDCs used in this development are polysiloxane and polycarbosilane. Polysiloxanes contain a silicon oxycarbide backbone when pyrolized up to 1000C. Polycarbosilane, an organosilicon polymer, contain a silicon-carbon backbone; around 1200C, beta-SiC begins to crystallize. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in composites. Basalt is a naturally occurring material found in volcanic rock. Continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. Thermal and mechanical testing includes oxyacetylene torch testing and three point bend testing.

  14. New data on the age of dolerites and basalts of Mendeleev Rise (Arctic Ocean)

    Science.gov (United States)

    Vernikovsky, V. A.; Morozov, A. F.; Petrov, O. V.; Travin, A. V.; Kashubin, S. N.; Shokal'sky, S. P.; Shevchenko, S. S.; Petrov, E. O.

    2014-02-01

    We present results of 40Ar/39Ar isotopic investigations concerning the dating of dolerites and basalts that were sampled during the Arctica-2012 polar expedition. Basalts were sampled by means of deep underwater drilling with wells up to 2 m in outcrops on the seafloor (basalts), and dolerite samples were obtained from the bottom of an escarp of Mendeleev Rise using a manipulator on the research submarine. The analysis results of the obtained mono-mineral fractions (amphibole, plagioclase, pyroxene) from the studied rocks yielded an Early Paleozoic age of the dolerites and basalts from Mendeleev Rise. The oldest ages obtained for amphibole reach 471.5 ± 18.1 and 466.9 ± 3.3 Ma, which corresponds to the Early-Middle Ordovician. The isotopic composition of argon was measured on two mass spectrometers: the Micromass Noble Gas 5400 (UK) and the Thermo Scientific Argus (Germany). The determined Early Paleozoic age of igneous rocks of Mendeleev Rise and seismic data obtained during the last Russian expedition Arctica-2012 [2] let us suppose that this continental block of the Earth's crust has a Precambrian basement similar to the basement identified for the New Siberian islands including the De Long archipelago.

  15. 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.

  16. STUDY ON THE BIODEGRADATION OF CELLULOSE FIBER/BASALTIC FIBER COMPOSITE PAPERBOARD

    Institute of Scientific and Technical Information of China (English)

    LinnaHu; FushanChen; MingxingAi; DekuShang; JunqingCai; JilinCao

    2004-01-01

    Influence factors on the biodegradation of cellulosefiber composite paperboard were studied experimentally and explained theoretically. The results show that the inorganic salts as nutriment added in the soil lixivium, the ratio of C/N, the temperature for biodegradation and content of basaltic fibers in the composite paperboard are the main influence factors.

  17. STUDY ON THE BIODEGRADATION OF CELLULOSE FIBER/BASALTIC FIBER COMPOSITE PAPERBOARD

    Institute of Scientific and Technical Information of China (English)

    Linna Hu; Fushan Chen; Mingxing Ai; Deku Shang; Junqing Cai; Jilin Cao

    2004-01-01

    Influence factors on the biodegradation of cellulose fiber composite paperboard were studied experimentally and explained theoretically. The results show that the inorganic salts as nutriment added in the soil lixivium, the ratio of C/N, the temperature for biodegradation and content of basaltic fibers in the composite paperboard are the main influence factors.

  18. Pb isotope evidence for contributions from different Iceland mantle components to Palaeogene East Greenland flood basalts

    DEFF Research Database (Denmark)

    Peate, David; Stecher, Ole

    2003-01-01

    We present new Pb isotope data on 21 samples of break-up-related flood basalts (56–54 Ma) from the Blosseville Kyst region of East Greenland. These samples show a considerable range in isotopic composition (206Pb/204Pb 17.6 to 19.3) that broadly correlates with compositional type. The ‘low-Ti’ type...

  19. Mineralogy of the mid-ocean-ridge basalt source from neodymium isotopic composition of abyssal peridotites.

    Science.gov (United States)

    Salters, Vincent J M; Dick, Henry J B

    2002-07-04

    Inferring the melting process at mid-ocean ridges, and the physical conditions under which melting takes place, usually relies on the assumption of compositional similarity between all mid-ocean-ridge basalt sources. Models of mantle melting therefore tend to be restricted to those that consider the presence of only one lithology in the mantle, peridotite. Evidence from xenoliths and peridotite massifs show that after peridotite, pyroxenite and eclogite are the most abundant rock types in the mantle. But at mid-ocean ridges, where most of the melting takes place, and in ophiolites, pyroxenite is rarely found. Here we present neodymium isotopic compositions of abyssal peridotites to investigate whether peridotite can indeed be the sole source for mid-ocean-ridge basalts. By comparing the isotopic compositions of basalts and peridotites at two segments of the southwest Indian ridge, we show that a component other than peridotite is required to explain the low end of the (143)Nd/(144)Nd variations of the basalts. This component is likely to have a lower melting temperature than peridotite, such as pyroxenite or eclogite, which could explain why it is not observed at mid-ocean ridges.

  20. An Experimental Melting—crystallization Study on Basalt at High Pressures

    Institute of Scientific and Technical Information of China (English)

    任国浩; 谢鸿森; 等

    1991-01-01

    A series of melting-crystallization experiments on alkali basalt samples from Minqing,Fujian Prov-ince was carried out in dry and water-bearing systems at high pressures.A high-pressure melting curve was obtained.The results indicate that clinopyroxene crystallized from basalt melt at 13.5-23.7kbar,spinel at 23.7-28.6kbar and garnet at>28.6kbar.With increasing pressure,the CaSiO3 contents of clinopyroxenes increase;and the FeSiO3 decreases,but the chemical composition of garnet does not show any significant difference.The minerals are larger and euhedral in the wa-ter-bearing system.Therefore,we consider that natural megacrysts of the basalt can crystallize from the water-bearing basalt magma at high pressure.So the megacysts may be derived from the upper mantle as a result of magmatic crystallization-fractionation under high pressure.

  1. Modeled Thickness of the Grande Ronde Basalt Geomodel Unit (grthk_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The grthk_f grid represents the modeled thickness of the Gronde Ronde Basalt geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists of...

  2. Modeled Top of the Wanapum Basalt Geomodel Unit (wntop_f)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The wntop_f grid represents the modeled elevation of the top of the Wanapum Basalt geomodel unit at a 500 foot resolution. It is one grid of a geomodel that consists...

  3. Physiological and Morphological Characteristics Among Ecotypes of Basalt Milkvetch (Astragalus Filipes)

    Science.gov (United States)

    Astragalus filipes Torr. ex A. Gray (basalt milkvetch or threadstalk milkvetch) is a legume that is widely distributed in western North America and holds promise for revegetation and restoration programs in the western U.S.A. Seed of 67 accessions was collected in 2003 from Utah, Nevada, Idaho, Ore...

  4. Derivation of Apollo 14 High-Al Basalts at Discrete Times: Rb-Sr Isotopic Constraints

    Science.gov (United States)

    Hui, H.; Neal, C. R.; Shih, C.-Y.; Nyquist, L. E.

    2012-03-01

    Four eruption episodes were identified for A-14 high-Al basalts. Rb-Sr isotopic data and ITE ratios show that their parental melt compositions of are correlated through mixing of evolved components with a relatively primitive magma ocean cumulate.

  5. Mantle potential temperature estimates of basalt from the surface of Venus

    Science.gov (United States)

    Shellnutt, J. Gregory

    2016-10-01

    The crater density and distribution of Venus indicates the average surface age is younger (≤1 Ga) than most terrestrial planets and satellites in the Solar System. The type and rate (i.e. equilibrium, catastrophic or differential) of volcanism associated with the stagnant lid tectonic system of Venus is a first order problem that has yet to be resolved but is directly related to the thermal conditions of the mantle. The calculated primary melt composition of basalt at the Venera 14 landing site is high-Mg basalt to picrite with a mantle potential temperature estimate similar to terrestrial ambient mantle (1370 ± 70 °C). The calculated accumulated fractional melting curves indicate the olivine compositions from the melt have Mg# of 89-91. The results show that the thermal regime required to generate the primary melt composition of the Venera 14 basalt was not anomalously high (i.e. mantle-plume system) but rather consistent with a lithospheric tensional rift system. The juxtaposition of high thermal regime structures (e.g. Beta Regio) and 'ambient' mantle potential temperature estimates of the Venera 14 basalt suggests that the relatively young surface of Venus is the result of volcanism from a combination of thermal systems that resurfaced the planet at variable rates.

  6. 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 fi...

  7. Tracking the weathering of basalts on Mars using lithium isotope fractionation models

    Science.gov (United States)

    Fairén, Alberto G.; Losa-Adams, Elisabeth; Gil-Lozano, Carolina; Gago-Duport, Luis; Uceda, Esther R.; Squyres, Steven W.; Rodríguez, J. Alexis P.; Davila, Alfonso F.; McKay, Christopher P.

    2015-04-01

    Lithium (Li), the lightest of the alkali elements, has geochemical properties that include high aqueous solubility (Li is the most fluid mobile element) and high relative abundance in basalt-forming minerals (values ranking between 0.2 and 12 ppm). Li isotopes are particularly subject to fractionation because the two stable isotopes of lithium—7Li and 6Li—have a large relative mass difference (˜15%) that results in significant fractionation between water and solid phases. The extent of Li isotope fractionation during aqueous alteration of basalt depends on the dissolution rate of primary minerals—the source of Li—and on the precipitation kinetics, leading to formation of secondary phases. Consequently, a detailed analysis of Li isotopic ratios in both solution and secondary mineral lattices could provide clues about past Martian weathering conditions, including weathering extent, temperature, pH, supersaturation, and evaporation rate of the initial solutions in contact with basalt rocks. In this paper, we discuss ways in which Martian aqueous processes could have lead to Li isotope fractionation. We show that Li isotopic data obtained by future exploration of Mars could be relevant to highlighting different processes of Li isotopic fractionation in the past, and therefore to understanding basalt weathering and environmental conditions early in the planet's history.

  8. INVESTIGATION OF SOFTENING AGENT PREPARATION AND PERFORMANCE OF HANDMADE ECOCOMPOSITES WITH CONIFEROUS WOOD AND BASALT FIBERS

    Institute of Scientific and Technical Information of China (English)

    Guangjian Wang; Deku Shang; Kailiang Zhang; Linna Hu; Zhenhua Guo

    2004-01-01

    In this investigation, basalt mineral fiber softening agent was prepared in order to obtain desirable flexible performance. Stability and physical chemistry natures of softening agent were evaluated by particle size distribution, dilution, storage and folding endurance etc. Constitutes of basalt and wood fibers were determined by energy dispersion analysis X-ray which served as an accessory of scanning electron microscopy (SEM-EDAX). Naturally degradable ecocomposite was prepared by basalt and wood fibers. The results of SEM observation illustrated that the wood and basalt fibers were blended uniformly. The impact factors of beating degree, content of wood fibers and adhesive etc. were discussed. The structure of the naturally degradable ecocomposite was contrasted with that of pure wood fibers and the cause of excellent filtration performance was analyzed. Compared with traditional methods, it was of saving wood resource,a large amount of water and reducing second pollution. As a consequence, the ecocomposite harmonized with environment and accorded with requirement of benignly friendly environment.

  9. Modeled Combined Extent of All Columbia River Basalt Units (CRB_extent4xconnections)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile was created as a boundary for the Columbia River Basalt extent and a buffered version was used to clip the geomodel unit grids. As part of a U.S....

  10. 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.

    The Central Indian Ocean Basin (CIOB) basalts are plagioclase-rich, while olivine and pyroxene are very few. The analyses of 41 samples reveal high FeO sup(T) (approx. 10-18 wt percent) and TiO sub(2) (approx. 1.4-2.7 wt percent) indicating a...

  11. Basalt Waste Isolation Project. Quarterly report, July 1, 1981-September 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.

    1981-11-01

    This document reports progress made in the Basalt Waste Isolation Project during the fourth quarter of fiscal year 1981. Efforts are described for the following programs of the project work breakdown structure: systems, waste package, site, repository, regulatory and institutional, test facilities, and in-situ test facilities.

  12. Basalt waste isolation project. Quarterly report, April 1, 1981-June 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.

    1981-08-01

    This document reports progress made in the Basalt Waste Isolation Project during the third quarter of fiscal year 1981. Efforts are described for the following programs of the project work breakdown structure: systems; waste package; site; repository; regulatory and institutional; test facilities; in situ test facilities.

  13. The decompression of basaltic magma into a sub-surface repository

    NARCIS (Netherlands)

    Bokhove, O.; Woods, A.W.

    2002-01-01

    We examine the ascent of volatile-rich basaltic magma through a vertical dike that intersects a horizontal tunnel of comparable cross-sectional area to the dike and located 300 $m$ below the surface and initially filled with air at atmospheric pressure. This process is a simplified representation of

  14. Field Validation of Supercritical CO 2 Reactivity with Basalts

    Energy Technology Data Exchange (ETDEWEB)

    McGrail, B. Peter; Schaef, Herbert T.; Spane, Frank A.; Cliff, John B.; Qafoku, Odeta; Horner, Jake A.; Thompson, Christopher J.; Owen, Antoinette T.; Sullivan, Charlotte E.

    2017-01-10

    Continued global use of fossil fuels places a premium on developing technology solutions to minimize increases in atmospheric CO2 levels. CO2 storage in reactive basalts might be one of these solutions by permanently converting injected gaseous CO2 into solid carbonates. Herein we report results from a field demonstration where ~1000 MT of CO2 was injected into a natural basalt formation in Eastern Washington State. Following two years of post-injection monitoring, cores were obtained from within the injection zone and subjected to detailed physical and chemical analysis. Nodules found in vesicles throughout the cores were identified as the carbonate mineral, ankerite Ca[Fe, Mg, Mn](CO3)2. Carbon isotope analysis showed the nodules are chemically distinct as compared with natural carbonates present in the basalt and clear correlation with the isotopic signature of the injected CO2. These findings provide field validation of rapid mineralization rates observed from years of laboratory testing with basalts.

  15. Influence of Basalt FRP Mesh Reinforcement on High-Performance Concrete Thin Plates at High Temperatures

    DEFF Research Database (Denmark)

    Hulin, Thomas; Lauridsen, Dan H.; Hodicky, Kamil;

    2015-01-01

    A basalt fiber–reinforced polymer (BFRP) mesh was introduced as reinforcement in high-performance concrete (HPC) thin plates (20–30 mm) for implementation in precast sandwich panels. An experimental program studied the BFRP mesh influence on HPC exposed to high temperature. A set of standard furn...

  16. Heterogeneity in small aliquots of Apolllo 15 olivine-normative basalt: Implications for breccia clast studies

    Science.gov (United States)

    Lindstrom, Marilyn M.; Shervais, John W.; Vetter, Scott K.

    1993-01-01

    Most of the recent advances in lunar petrology are the direct result of breccia pull-apart studies, which have identified a wide array of new highland and mare basalt rock types that occur only as clasts within the breccias. These rocks show that the lunar crust is far more complex than suspected previously, and that processes such as magma mixing and wall-rock assimilation were important in its petrogenesis. These studies are based on the implicit assumption that the breccia clasts, which range in size from a few mm to several cm across, are representative of the parent rock from which they were derived. In many cases, the aliquot allocated for analysis may be only a few grain diameters across. While this problem is most acute for coarse-grained highland rocks, it can also cause considerable uncertainty in the analysis of mare basalt clasts. Similar problems arise with small aliquots of individual hand samples. Our study of sample heterogeneity in 9 samples of Apollo 15 olivine normative basalt (ONB) which exhibit a range in average grain size from coarse to fine are reported. Seven of these samples have not been analyzed previously, one has been analyzed by INAA only, and one has been analyzed by XRF+INAA. Our goal is to assess the effects of small aliquot size on the bulk chemistry of large mare basalt samples, and to extend this assessment to analyses of small breccia clasts.

  17. Water in the Early Differentiated Asteroids: Insight from Apatite in Basaltic Eucrites

    Science.gov (United States)

    Koike, M.; Iizuka, T.; Takahata, N.; Sano, Y.; Haba, M. K.

    2016-08-01

    To understand the water history in early differentiated bodies, we analyze H2O contents and U-Pb ages in apatites from several basaltic eucrites. Our results indicate that at least some part of the Vesta’s crust was anhydrous at 4.5Ga.

  18. Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes

    Energy Technology Data Exchange (ETDEWEB)

    Dalmora, Adilson C. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Institute for Environmental Assessment and Water Studies (IDÆA), Spanish National Research Council (CSIC), C/Jordi Girona 18-26, 08034 Barcelona (Spain); Ramos, Claudete G.; Oliveira, Marcos L.S. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Teixeira, Elba C. [Fundação Estadual de Proteção Ambiental Henrique Luis Roessler, Porto Alegre, RS (Brazil); Kautzmann, Rubens M.; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração. Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Brum, Irineu A.S. de [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500. Bairro Agronomia. CEP: 91501-970 Porto Alegre, RS (Brazil); and others

    2016-01-01

    Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during “stonemeal” soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO{sub 2}, Al{sub 2}O{sub 3}, and Fe{sub 2}O{sub 3,} with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano

  19. First Recovery of Submarine Basalts from the Chukchi Borderland and Alpha / Mendeleev Ridge, Arctic Ocean

    Science.gov (United States)

    Andronikov, A.; Mukasa, S.; Mayer, L. A.; Brumley, K.

    2008-12-01

    In addition to multibeam bathymetric mapping of the Amerasia Basin in the high Arctic Ocean, the August- September 2008 cruise of USCGC Icebreaker HEALY (HLY0805) conducted a total of seven dredging profiles along the southern sectors of the Alpha/Mendeleev Ridge and in the northernmost region of Northwind Ridge of Chukchi Borderland. Five of the seven dredges were recovered on relatively gentle slopes (30-40°) and yielded mostly mud with a small number of fragments of sedimentary rocks and ice rafted debris (IRD), which indicates either rapid sedimentation rates on the bathymetrically high features sampled or lack of recently active volcanism on these features. Two dredges taken from steep escarpments with slopes (> 55°) at >3.5 km depth recovered some of the first known submarine basaltic samples from the Arctic Ocean floor away from the Gakkel Ridge. Ragged, freshly exposed edges indicate that these samples were broken from outcrop rather than being IRD. In some cases (e.g., a rise on the ocean floor between the Alpha/Mendeleev Ridge and Northwind Ridge) the samples have well-preserved pillow-basalt structures with fresh glassy rims up to 4 cm thick. Inward from the rims, the rocks are dark-grey lavas, some with visible plagioclase laths and rare phenocrysts up to 0.5 mm in length, some with visible signs of alteration such as local occurrence of chlorite. Surfaces that were exposed to water can be covered with a thin black film of Mn oxides. Occurrence of this volcanism away from any obvious spreading centers compels us to hypothesize that forthcoming geochemical analyses are likely to identify these rocks as the first Arctic Ocean floor samples to exhibit ocean island basalt compositions. The dredge taken from the northern slope of Northwind Ridge, along slopes as steep as > 45°, recovered a variety of rock types including sedimentary and basaltic rocks. Some of the basalts have columnar jointing (the size of the columns is only up to 5-6 cm across

  20. Simulation and Experimental Determination of Technological Liquid Molding Parameters of Tubing Basalt Insulation

    Directory of Open Access Journals (Sweden)

    Yu. V. Badanina

    2015-01-01

    Full Text Available The article is dedicated to one of the most important and urgent tasks in mechanical engineering development - the creation of low-density and environmentally-friendly thermoinsulation from available cheap basalt fibers for products to operate at temperatures up to 700°C.One of the most effective applications of such thermo-insulation is to develop and provide highly porous coatings from short basalt fibers by liquid filtration for tubing (T to supply superheated up to 420° C steam under pressure of 35 MPa in the deep layers with severe highviscosity oil. Tubing with the short low-density basalt insulation can be used for a greater depth than the vacuum-insulated tubing, which are also called "thermo-cases", and do not fully meet business needs for long-term reliability of oil vacuum tubes, too large mass per unit length of their design and, as a consequence, the impossibility to use such pipes for deep wells.The aim of the work is to simulate a liquid filtration process of short fibers and determine technological parameters of producing thermal insulation coatings of tubing pipes from basalt fibers and mineral binder shaped as cylinders and cylindrical shells. The paper proposes a mathematical model of free filtration deposition of short fibers from liquid slurry, which describes dynamics of creating thermal insulation products and allows us to determine the rational parameters of their manufacturing process. It shows methods to improve the products quality while forming the thermal insulation by filtration through additional vacuum deposition of a filtrate chamber and the final prepressing of sediment layer, giving dimensions and shape to the final product.The paper defines a prescription hydro mass composition. It shows that to increase the compressive strength of highly fibrous rings and cylindrical shells it is necessary to use based on oxide А12O3 5-7% by weight mineral binder, which fixes basalt fibers in places of their contacts. It

  1. Effect of Miocene basaltic volcanism in Shanwang (Shandong Province, China) on environmental changes

    Institute of Scientific and Technical Information of China (English)

    GUO; ZhengFu; LIU; JiaQi; CHEN; XiaoYu

    2007-01-01

    Miocene (16-10 Ma) basalts, together with significantly well-preserved fossils (including animal and plant fossils) in the contemporaneously tephra-rich Maar sediments, are located in Shanwang volcanic region, Shandong Province, China. Distribution area of the basaltic eruption products is about 240 km2. Detailed field observations indicate that most of basaltic rocks are fissure eruptive products and some are central eruptives constrained by linear faults. The well-preserved fossils in the lacustrine deposits have been considered to be a result of mass mortalities. Based on physically volcanologic modeling results, eruption column of the basaltic fissure activities in the Shanwang volcanic region is estimated to have entered the stratosphere. Petrographic observations indicate that the basalts have porphyritic textures with phenocrysts of olivine, pyroxene, plagioclase feldspar and alkali feldspar setting in groundmass of plagioclase feldspar, alkali feldspar, quartz, apatite and glass. Based on observations of tephra, tuff and tuffites collected in the Maar sediments of the Shanwang area, we determined major element oxide concentrations and volatile composition of melt inclusions in phenocrysts and matrix glasses by electron microprobe analysis. Volatile (including S, Cl, F and H2O) concentrations erupted into the stratosphere were estimated by comparing pre- and post-eruptive volatile concentrations. Our determination results show that contents of S, Cl, F and H2O emitted into the stratosphere were 0.18%-0.24%, 0.03%-0.05%, 0.03%-0.05% and 0.4%-0.6%, respectively, which was characterized by high-S contents erupted. Amounts of volatiles emitted in the Shanwang volcanic region are much higher than those in eruptions which had a substantial effect on climate and environment. According to the compositions and amounts of the volatiles erupted from the Miocene basaltic volcanism in Shanwang, we propose a hypothesis that volatile-rich basaltic volcanism could result in

  2. 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

  3. The effect of a thin weak layer covering a basalt block on the impact cratering process

    Science.gov (United States)

    Dohi, Koji; Arakawa, Masahiko; Okamoto, Chisato; Hasegawa, Sunao; Yasui, Minami

    2012-04-01

    To clarify the effect of a surface regolith layer on the formation of craters in bedrock, we conducted impact-cratering experiments on two-layered targets composed of a basalt block covered with a mortar layer. A nylon projectile was impacted on the targets at velocities of 2 and 4 km s-1, and we investigated the crater size formed on the basalt. The crater size decreased with increased mortar thickness and decreased projectile mass and impact velocity. The normalized crater volume, πV, of all the data was successfully scaled by the following exponential equation with a reduction length λ0: π=b0πY-b1exp(-λ/λ0), where λ is the normalized thickness T/Lp, T and Lp are the mortar thickness and the projectile length, respectively, b0 and b1 are fitted parameters obtained for a homogeneous basalt target, 10-2.7±0.7 and -1.4 ± 0.3, respectively, and λ0 is obtained to be 0.38 ± 0.03. This empirical equation showing the effect of the mortar layer was physically explained by an improved non-dimensional scaling parameter, πY∗, defined by πY∗=Y/(ρup2), where up was the particle velocity of the mortar layer at the boundary between the mortar and the basalt. We performed the impact experiments to obtain the attenuation rate of the particle velocity in the mortar layer and derived the empirical equation of {u}/{v}=0.50exp-{λ}/{1.03}, where vi is the impact velocity of the projectile. We propose a simple model for the crater formation on the basalt block that the surface mortar layer with the impact velocity of up collides on the surface of the basalt block, and we confirmed that this model could reproduce our empirical equation showing the effect of the surface layer on the crater volume of basalt.

  4. Expanded mode lasers for telecommunications applications

    Science.gov (United States)

    Lealman, Ian F.

    This thesis describes the development of a long wavelength (1.55 μm) expanded mode semiconductor laser. The increased spot size of the laser improves both the coupling efficiency to cleaved fibre and fibre alignment tolerances and reduces packaging cost. In this type of device the strength of the waveguide is gradually reduced towards the front facet allowing the mode to adiabatically expand so that the laser mode is better matched in size to that of a cleaved fibre. This can be achieved by either reducing the refractive index of the guide or reducing the amount of material in the core. The structure chosen was a buried heterostructure laser that utilised a twin guide consisting of an upper higher refractive index guide (the active region of the laser) above a weak passive guide. The width of the active region was reduced along part of the device allowing the mode to expand into the weak underlying guide. The guide structure was optimised using a variable grid finite difference mode solver, and the taper length calculated by an approximation to Love's method. Detailed results are presented for the measured light-current characteristic, farfield and coupling loss to cleaved fibre. These coupling losses were compared to the calculated data thus allowing the waveguide design to be optimised. Several iterations in the design of the device were undertaken, with the aim of reducing the coupling loss to cleaved single mode fibre without significantly compromising the laser performance. The final device design had extremely low coupling losses as low as 1.2 dB to cleaved fibre. Finally, the positive impact this device had on passive alignment using a silicon motherboard is examined, and the application this technology to a range of other optoelectronic components is discussed.

  5. 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

    2016-11-01

    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.

  6. Red Sea rift-related Quseir basalts, central Eastern Desert, Egypt: Petrogenesis and tectonic processes

    Science.gov (United States)

    Farahat, Esam S.; Ali, Shehata; Hauzenberger, Christoph

    2017-01-01

    Mineral and whole-rock chemistry of Red Sea rift-related Tertiary basalts from south Quseir city, central Eastern Desert of Egypt is presented to investigate their petrogenesis and relationship to tectonic processes. The south Quseir basalts (SQB) are classified as high-Ti (TiO2 >2 wt.%) subalkaline transitional lava emplaced in an anorogenic tectonic setting. Their Mg# varies from 48 to 53 indicating the evolved nature of the SQB. Pearce element ratios suggest that the SQB magmas evolved via fractional crystallization of olivine + clinopyroxene ± plagioclase, but the absence of Eu anomalies argues against significant plagioclase fractionation. Clinopyroxene compositions provide evidence for polybaric fractionation of the parental mafic magmas. Estimated temperatures of crystallization are 1015 to 1207 °C for clinopyroxene and 1076 to 1155 °C for plagioclase. These values are interpreted to result from early stage crystallization of clinopyroxene followed by concurrent crystallization of clinopyroxene and plagioclase. The incompatible trace element signatures of the SQB (La/Ba = 0.08-0.10 and La/Nb = 0.89-1.04) are comparable to those of ocean island basalts (OIB) generated from an asthenospheric mantle source unaffected by subduction components. Modeling calculations indicate that the SQB primary magmas were derived from 4-5% partial melting of a garnet-bearing lherzolite mantle source. The NE Egyptian basaltic volcanism is spatially and temporally related to Red Sea rifting and to the local E-W striking faults, confirming a relationship to tectonic activity. Our results suggest that the extensional regime associated with Red Sea rifting controlled the generation of the Egyptian basalts, likely as a result of passive upwelling of asthenospheric mantle.

  7. Mantle Origin of Silicic Calc-alkaline Basalts to Andesites in the Central Mexican Volcanic Belt

    Science.gov (United States)

    Straub, S. M.; Zellmer, G. F.; Gómez-Tuena, A.; Stuart, F.; Espinasa-Perena, R.; Cai, Y.

    2011-12-01

    The Quaternary central Mexican Volcanic Belt, constructed on ~50 km thick continental crust, erupts a broad spectrum of basaltic to dacitic calc-alkaline magmas with the arc-typical high ratios of large-ion lithophile to high-field strength elements. In order to understand their genesis, we investigated high-Mg# olivine-phyric calc-alkaline basalts to andesites from Holocene monogenetic volcanoes Tuxtepec (50.2 wt% SiO2; 9.7 wt% MgO), Yecahuazac (53.1;8.0), Suchiooc Cone (53.2;9.2), Guespalapa (54.4-61.2;5.3-7.9) and Cuatepel (55.6-58.9;5.4-7.5), and as well as one basaltic andesite from composite volcano Popocateptl (56.7;6.9). The high 3He/4He (7.3 ± 0.3 Ra; n=16) of olivine phenocrysts that crystallize at upper crustal levels, and the limited range of Sr-Nd-Hf isotope ratios preclude any significant crustal contamination of these magmas. Moreover, small, but significant differences in Sr-Nd-Hf isotope ratios and the variations of olivine phenocrysts in the Fo-Ni space conclusively rule out that these magmas were related through fractional crystallization. Consequently, the basaltic to andesitic magmas must originate from the sub-arc mantle. Building on the high-Ni content of the olivines that by far exceed Ni abundances of olivines in partial melts of peridotite, we propose that the subarc MVB mantle contains segregations of silica-excess and silica-deficient 'reaction pyroxenites' that formed through infiltration of highly reactive silicic fluids or melts from slab. Upon melting, the pyroxenites produce dacitic and basaltic initial melts, respectively, that mix in variable proportions during ascent through mantle and crust. This genetic model links the silica enrichment of the arc magmas directly to the silica flux from slab, with no requirement for any significant melt silica increase in the overlying crust.

  8. Evidence from Sardinian basalt geochemistry for recycling of plume heads into the Earth's mantle.

    Science.gov (United States)

    Gasperini, D; Blichert-Toft, J; Bosch, D; Del Moro, A; Macera, P; Télouk, P; Albarède, F

    2000-12-07

    Up to 10 per cent of the ocean floor consists of plateaux--regions of unusually thick oceanic crust thought to be formed by the heads of mantle plumes. Given the ubiquitous presence of recycled oceanic crust in the mantle source of hotspot basalts, it follows that plateau material should also be an important mantle constituent. Here we show that the geochemistry of the Pleistocene basalts from Logudoro, Sardinia, is compatible with the remelting of ancient ocean plateau material that has been recycled into the mantle. The Sr, Nd and Hf isotope compositions of these basalts do not show the signature of pelagic sediments. The basalts' low CaO/Al2O3 and Ce/Pb ratios, their unradiogenic 206Pb and 208Pb, and their Sr, Ba, Eu and Pb excesses indicate that their mantle source contains ancient gabbros formed initially by plagioclase accumulation, typical of plateau material. Also, the high Th/U ratios of the mantle source resemble those of plume magmas. Geochemically, the Logudoro basalts resemble those from Pitcairn Island, which contain the controversial EM-1 component that has been interpreted as arising from a mantle source sprinkled with remains of pelagic sediments. We argue, instead, that the EM-1 source from these two localities is essentially free of sedimentary material, the geochemical characteristics of these lavas being better explained by the presence of recycled oceanic plateaux. The storage of plume heads in the deep mantle through time offers a convenient explanation for the persistence of chemical and mineralogical layering in the mantle.

  9. Wellbore cement fracture evolution at the cement–basalt caprock interface during geologic carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hun Bok; Kabilan, Senthil; Carson, James P.; Kuprat, Andrew P.; Um, Wooyong; Martin, Paul F.; Dahl, Michael E.; Kafentzis, Tyler A.; Varga, Tamas; Stephens, Sean A.; Arey, Bruce W.; Carroll, KC; Bonneville, Alain; Fernandez, Carlos A.

    2014-08-07

    Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 ºC and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. Micro-XRD and SEM-EDS data collected along the cement-basalt interface after 3-month reaction with CO2-saturated groundwater indicate that carbonation of cement matrix was extensive with the precipitation of calcite, aragonite, and vaterite, whereas the alteration of basalt caprock was minor. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. This study demonstrates that XMT imaging coupled with CFD modeling represent a powerful tool to visualize and quantify fracture evolution and permeability change in geologic materials and to predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal systems.

  10. Shallow Miocene basaltic magma reservoirs in the Bahia de Los Angeles basin, Baja California, Mexico

    Science.gov (United States)

    Delgado-Argote, Luis A.; García-Abdeslem, Juan

    1999-01-01

    The basement in the Bahı´a de Los Angeles basin consists of Paleozoic metamorphic rocks and Cretaceous granitoids. The Neogene stratigraphy overlying the basement is formed, from the base to the top, by andesitic lava flows and plugs, sandstone and conglomeratic horizons, and Miocene pyroclastic flow units and basaltic flows. Basaltic dikes also intrude the whole section. To further define its structure, a detailed gravimetric survey was conducted across the basin about 1 km north of the Sierra Las Flores. In spite of the rough and lineal topography along the foothills of the Sierra La Libertad, we found no evidence for large-scale faulting. Gravity data indicates that the basin has a maximum depth of 120 m in the Valle Las Tinajas and averages 75 m along the gravimetric profile. High density bodies below the northern part of the Sierra Las Flores and Valle Las Tinajas are interpreted to be part of basaltic dikes. The intrusive body located north of the Sierra Las Flores is 2.5 km wide and its top is about 500 m deep. The lava flows of the top of the Sierra Las Flores, together with the distribution of basaltic activity north of this sierra, suggests that this intrusive body continues for 20 km along a NNW-trending strike. Between the sierras Las Flores and Las Animas, a 0.5-km-wide, 300-m-thick intrusive body is interpreted at a depth of about 100 m. This dike could be part of the basaltic activity of the Cerro Las Tinajas and the small mounds along the foothills of western Sierra Las Animas. The observed local normal faulting in the basin is inferred to be mostly associated with the emplacement of the shallow magma reservoirs below Las Flores and Las Tinajas.

  11. The Oxidation State of Terrestrial Basalts and its Link with the Mantle

    Science.gov (United States)

    Mallmann, G.; O'Neill, H. S.; Berry, A. J.; Norman, M. D.; Eggins, S. M.; Kamenetsky, V.; Turner, S.; Smith, I. E.; Ballhaus, C.

    2011-12-01

    The prevailing paradigm is that the Earth's mantle is both laterally and vertically heterogeneous in regards to its oxidation state. This view has been motivated by the observation that, on average, primitive island arc basalts (IAB) preserve Fe3+/Fe2+ higher than ocean island (OIB) and, particularly, mid-ocean ridge basalts (MORB), and reinforced by the higher oxygen fugacities (fO2) determined in lithospheric (mantle wedge) arc peridotites. fO2 measurements in peridotites equilibrated over a range of pressures have also led to the notion that the mantle becomes more reduced with depth. V and Sc behave very similarly during partial melting of the mantle, but while V is redox-sensitive Sc is not. Their ratio in basalts has therefore a memory of the redox conditions during partial melting. Within the many assumptions involved in forward trace-element modeling, the bulk-rock V/Sc of MORBs, OIBs and IABs indicate that the partial melting events responsible for their genesis occurred at a relatively narrow range of fO2s between QFM and QFM-1. V olivine-liquid partition coefficients are also sensitive to oxidation state (normalization to Sc is useful to minimize the effect of variables other than fO2), and the values determined between olivine phenocrysts (Fo76-90) and quenched basaltic melts suggest that, at the time of olivine crystallization, terrestrial basalts have already oxidized about 1 log fO2 unit (IABs even more so, approximately 2 log fO2 units). The results reveal no statistically significant distinction between the oxidation states of MORBs and OIBs. This has been confirmed by Fe3+/Fe2+ determined by XANES.

  12. Partial crystallization of picritic melt and its applications for the genesis of high-Ti and low-Ti basalts

    Science.gov (United States)

    Yang, J.; WANG, C.; Jin, Z.; Jin, S.; Yan, S.

    2015-12-01

    Geochemical and petrological studies have revealed the existence of high-Ti and low-Ti basalts in large igneous provinces (LIPs). However the originate of these high-Ti and low-Ti magmas are still under debate. Several different mechanisms have been proposed: (1) the high-Ti basalts are formed by the melting of mantle plume containing recycled oceanic crust (Spandler et al., 2008) while low-Ti basalts are formed by the melting of subcontinental lithospheric mantle (Xiao et al., 2004); (2) both high-Ti and low-Ti basalts are from mantle plume source, but the production of high-Ti basalts are associated with the thick lithosphere while the low-Ti basalts are controlled by the thin lithosphere (Arndt et al., 1993); (3) they are derived from the different degrees of melting, with high-Ti basalts representing low degree of partial melting of mantle plume (Xu et al., 2004). The low Mg# (below 0.7) of high-Ti and low-Ti basalts provides that they are far away from direct melting of mantle peridotite. In addition, seismic data indicate unusually high seismic velocities bodies beneath the LIPs which explained by the fractionated cumulates from picritic magmas (Farnetani et al., 1996). Therefore, we believed that the crystallization differentiation process might play a more significant role in the genesis of high-Ti and low-Ti basalts.In order to investigate the generation of high-Ti and low-Ti basalts, a series of high pressure and high temperature partial crystallization experiments were performed at pressures of 1.5, 3.0 and 5.0 GPa and a temperature range of 1200-1700℃. The starting material is picrate glass with relative high TiO2 (2.7 wt %), which is synthesized according to the chemical composition of primary magmas of Emeishan LIP (Xu et al., 2001). The experimental results show that: (1) At a given pressure, the TiO2 content is decreased with increasing melt fraction; (2) At a given melt fraction, the TiO2 content of melts is increased with increasing pressure. On

  13. Expanding Slayer Statutes to Elder Abuse.

    Science.gov (United States)

    Piel, Jennifer

    2015-09-01

    Common law has a dictum that people must not benefit from their crimes. In years past, states have enacted slayer rules to prevent killers from inheriting from their victims. The specific criteria and applicability of slayer rules vary by jurisdiction. Recently, several states, including Washington, have expanded their slayer rules to disqualify persons from inheriting if they have been involved in abuse or financial exploitation of the deceased. Reviewed herein are the abuse disinheritance laws, the relationship of the laws to concepts of testamentary capacity and undue influence, and the relevance to forensic psychiatric evaluations.

  14. Sinopec Strives to Expand Domestic Market

    Institute of Scientific and Technical Information of China (English)

    Zhang Yan

    2001-01-01

    @@ China Petrochemical Corporation (Sinopec) strives to expand its domestic market share during the Tenth Five-Year Plan period (2001~2005). The assets of Sinopec totaled 536.3 billion yuan at the end of 2000 while the business income reached 375.4billion yuan. Sinopec produced 37.24 million tons of crude oil and 3.916 billion cubic meters of natural gas and processed 105.47million tons of crude and 2.165million tons of ethylene in 2000.

  15. Concurrent Manipulation of Expanded AVL Trees

    Institute of Scientific and Technical Information of China (English)

    章寅; 许卓群

    1998-01-01

    The concurrent manipulation of an expanded AVL tree(EAVL tree)s considered in this paper.The presented system can support any number of concurrent processes which perform searching,insertion and deletion on the tree.Simulation results indicate the high performance of the system.Elaborate techniques are used to achieve such a system unavailable based on any known algorithms.Methods developed in this paper may provide new insights into other problems in the area of concurrent search structure manipulation.

  16. Familiarity expands space and contracts time.

    Science.gov (United States)

    Jafarpour, Anna; Spiers, Hugo

    2017-01-01

    When humans draw maps, or make judgments about travel-time, their responses are rarely accurate and are often systematically distorted. Distortion effects on estimating time to arrival and the scale of sketch-maps reveal the nature of mental representation of time and space. Inspired by data from rodent entorhinal grid cells, we predicted that familiarity to an environment would distort representations of the space by expanding the size of it. We also hypothesized that travel-time estimation would be distorted in the same direction as space-size, if time and space rely on the same cognitive map. We asked international students, who had lived at a college in London for 9 months, to sketch a south-up map of their college district, estimate travel-time to destinations within the area, and mark their everyday walking routes. We found that while estimates for sketched space were expanded with familiarity, estimates of the time to travel through the space were contracted with familiarity. Thus, we found dissociable responses to familiarity in representations of time and space. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc.

  17. Historical Notes on the Expanding Universe

    Science.gov (United States)

    Way, Michael J.; Belenkyi, Ari; Nussbaumer, Harry; Peacock, John

    2014-01-01

    The article Measuring the Hubble constant by Mario Livio and Adam Riess (Physics Today, October 2013, page 41) reviewed studies of the expanding universe from the 1920s to the present. Although the history of the subject underwent considerable compression to fit the length of a magazine article, we think it may leave a misleading impression of some of the key steps to our current understanding. We therefore offer the following clarifications. Most significantly, papers by Arthur Eddington and by Willem de Sitter in 1930, who successfully promoted Georges Lematres 1927 article for the Scientific Society of Brussels, effected a paradigm shift in interpretation of extragalactic redshifts in 1930. Before then, the astronomical community was generally unaware of the existence of nonstatic cosmological solutions and did not broadly appreciate that redshifts could be thought of locally as Doppler shifts in an expanding matter distribution. Certainly, in 1929 Edwin Hubble referred only to the de Sitter solution of 1917. At the time, the relation between distance and redshift predicted in that model was generally seen purely as a manifestation of static spacetime curvature.

  18. Unintended Consequences of Expanding the Genetic Alphabet.

    Science.gov (United States)

    Pollum, Marvin; Ashwood, Brennan; Jockusch, Steffen; Lam, Minh; Crespo-Hernández, Carlos E

    2016-09-14

    The base pair d5SICS·dNaM was recently reported to incorporate and replicate in the DNA of a modified strain of Escherichia coli, thus making the world's first stable semisynthetic organism. This newly expanded genetic alphabet may allow organisms to store considerably more information in order to translate proteins with unprecedented enzymatic activities. Importantly, however, there is currently no knowledge of the photochemical properties of d5SICS or dNaM-properties that are central to the chemical integrity of cellular DNA. In this contribution, it is shown that excitation of d5SICS or dNaM with near-visible light leads to efficient trapping of population in the nucleoside's excited triplet state in high yield. Photoactivation of these long-lived, reactive states is shown to photosensitize cells, leading to the generation of reactive oxygen species and to a marked decrease in cell proliferation, thus warning scientists of the potential phototoxic side effects of expanding the genetic alphabet.

  19. Expanding ester biosynthesis in Escherichia coli.

    Science.gov (United States)

    Rodriguez, Gabriel M; Tashiro, Yohei; Atsumi, Shota

    2014-04-01

    To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l(-1)). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters.

  20. "Phase freezeout" in isentropically expanding matter

    CERN Document Server

    Iosilevskiy, Igor

    2014-01-01

    Features of isentropic expansion of warm dense matter (WDM) created by intense energy fluxes (strong shock compression or instant isochoric heating by laser or heavy ions) are under discussion in situation when ($i$) -- thermodynamic trajectory of such expansion crosses binodal of liquid-gas phase transition, and ($ii$) -- expansion within the two-phase region is going along equilibrium branch (not metastable one) of the two-phase mixture isentrope. It is known in the plane case that because of break in the expansion isentrope at binodal point (in $P-V$ plane) i.e. jump of sound velocity in this point, there appears extended zone ("boiling layer") of uniformity in expanding material with constant thermodynamic and kinematic parameters. It corresponds just to the state on this binodal of boiling liquid. The point is that because of self-similarity of such expansion (in plane case) this boiling layer contains finite and fixed part of whole expanding material. This property makes it possible (at least formally) ...

  1. Appraisal and evolution of hydrochemical processes from proximity basalt and granite areas of Deccan Volcanic Province (DVP) in India

    Science.gov (United States)

    Sonkamble, Sahebrao; Sahya, Ashalata; Mondal, N. C.; Harikumar, P.

    2012-05-01

    SummaryThis paper deals with a systematic hydrochemical study carried out at proximity basalt and granite areas of Deccan Volcanic Province (DVP) in India to assess groundwater quality and evaluate the hydrochemical processes. A total of 40 groundwater samples were collected equally from these areas and analyzed. Results showed that the groundwaters rich in alkaline earth in the basalt and alkali rich element in the granite. The dominancy of cations was observed as Ca2+ > Mg2+ > Na+ > K+ in the basalt and Na+ > Mg2+ > K+ > Ca2+ in the granite, whereas anions as HCO3->Cl>SO42- and Cl>HCO3->SO42-, respectively. Hydrochemical processes were identified with the helps of ion exchange, carbonate weathering and dissolution, multiple ionic ratios, and silicate weathering, which shown the predominance of carbonate, dolomite, calcite and silicate (anorthite) weathering in basalt, but in granite, silicate (alkali feldspar) weathering was dominated. Factor analysis also showed that there were multiple processes acting on groundwaters, were separated from the main cluster. Salinity, Sodium Absorption Ratio (SAR), Soluble Sodium Percentage (SSP), Residual Sodium Carbonate (RSC), Kelley's Ratio (KR) and Permeability Index (PI) in well samples showed that groundwater in basalt was more suitable for irrigation purposes. Further, a digital elevation model (DEM) was generated using Global mapper (8.0 version) software, which aided to decipher the thickness of basalt trap, and vertical transition zone of basaltic (trap) and granitic (basement) aquifer at this DVP comprising with the well depths and groundwater chemistry.

  2. MARIUS HILLS REGION, MOON: Stratigraphy of low shields and mare basalts

    Science.gov (United States)

    Gebhart, Jennifer; Hiesinger, Harry; van der Bogert, Carolyn; Hendrik Pasckert, Jan; Weinauer, Julia; Lawrence, Samuel; Stopar, Julie; Robinson, Mark

    2016-04-01

    The Marius Hills region consists of more than 250 individual basaltic low shields (usually referred to as "domes") and cones, located on a broad topographic rise. The bases of numerous low shields have slope angles of ~2-3° whereas the upper portions have slopes of ~6-7° [1], interpreted to reflect changes in composition over time [1]. However, the absence of spectral differences between the two dome morphologies and the surrounding mare basalts suggests that the observed morphologies are more plausibly explained by changes in effusion rates, temperature (viscosity), and/or crystallization over time [e.g., 2]. Previous studies indicate that volcanism in this region occurred in the Upper Imbrian (3.2-3.8 Ga) [3], although several other authors reported ages ranging from the Imbrian (~3.3 Ga) to the Eratosthenian (~2.5 Ga) [e.g., 1,2,4]. [2,5] reported that all low shields are embayed by younger mare units, indicating that they formed during an older stage of volcanic activity. Mare basalts surrounding the Marius Hills exhibit absolute model ages of 1.2-3.7 Ga [6]. We used 36 LRO NAC images to perform crater size-frequency distribution (CSFD) measurements. The images were calibrated and map-projected with ISIS 3 and imported into ArcGIS. Within ArcGIS, we used CraterTools [7] to perform our CSFD measurements. The crater size-frequency distributions were then plotted with CraterStats [8], using the production and chronology functions of [9]. We conducted CSFD measurements for 50 Marius Hills low shields. Our count area sizes ranged from 1.06 x 101 to 8.75 x 101 km2; those for adjacent basalts varied between 6.17 x 100 and 8.01 x 101 km2. We determined absolute model ages (AMAs) of 1.03 to 3.65 Ga for the low shields and did not find a spatial correlation of ages versus their locations. CSFD measurements for 27 adjacent basalts show AMAs of 1.20-3.69 Ga. Of those basalts, 24 exhibit AMAs of 3-3.5 Ga; there is no correlation of AMAs and the geographic position of the

  3. Dissolution-precipitation reactions and permeability evolution from reactions of CO2-rich aqueous solutions with fractured basalt

    Science.gov (United States)

    Wells, R. K.; Xiong, W.; Bae, Y.; Sesti, E.; Skemer, P. A.; Giammar, D.; Conradi, M.; Ellis, B. R.; Hayes, S. E.

    2015-12-01

    The injection of CO2 into fractured basalts is one of several possible solutions to mitigate global climate change; however, research on carbonation in natural basalts in relation to carbon sequestration is limited, which impedes our understanding of the processes that may influence the viability of this strategy. We are conducting bench-scale experiments to characterize the mineral dissolution and precipitation and the evolution of permeability in synthetic and natural basalts exposed to CO2-rich fluids. Analytical methods include optical and electron microscopy, electron microprobe, Raman spectroscopy, nuclear magnetic resonance (NMR), and micro X-ray computed tomography (μCT) with variable flow rates. Reactive rock and mineral samples consist of 1) packed powders of olivine or natural basalt, and 2) sintered cores of olivine or a synthetic basalt mixture. Each sample was reacted in a batch reactor at 100 °C, and 100 bars CO2. Magnesite is detected within one day in olivine packed beds, and within 15 days in olivine sintered cores. Forsterite and synthetic basalt sinters were also reacted in an NMR apparatus at 102 °C and 65 bars CO2. Carbonate signatures are observed within 72 days of reaction. Longer reaction times are needed for carbonate precipitation in natural basalt samples. Cores from the Columbia River flood basalt flows that contain Mg-rich olivine and a serpentinized basalt from Colorado were cut lengthwise, the interface mechanically roughened or milled, and edges sealed with epoxy to simulate a fractured interface. The cores were reacted in a batch reactor at 50-150 °C and 100 bars CO2. At lower temperatures, calcite precipitation is rare within the fracture after 4 weeks. At higher temperatures, numerous calcite and aragonite crystals are observed within 1 mm of the fracture entrance along the roughened fracture surface. In flow-through experiments, permeability decreased along the fracture paths within a few hours to several days of flow.

  4. Sm-Nd and Rb-Sr Isotopic Studies of Meteorite Kalahari 009: An Old VLT Mare Basalt

    Science.gov (United States)

    Shih, C.-Y.; Nyquist, L. E.; Reese, Y.; Bischoff, A.

    2008-01-01

    Lunar meteorite Kalahari 009 is a fragmental basaltic breccia contain ing various very-low-Ti (VLT) mare basalt clasts embedded in a fine-g rained matrix of similar composition. This meteorite and lunar meteorite Kalahari 008, an anorthositic breccia, were suggested to be paired mainly due to the presence of similar fayalitic olivines in fragment s found in both meteorites. Thus, Kalahari 009 probably represents a VLT basalt that came from a locality near a mare-highland boundary r egion of the Moon, as compared to the typical VLT mare basalt samples collected at Mare Crisium during the Luna-24 mission. The concordant Sm-Nd and Ar-Ar ages of such a VLT basalt (24170) suggest that the extrusion of VLT basalts at Mare Crisium occurred 3.30 +/- 0.05 Ga ag o. Previous age results for Kalahari 009 range from approximately 4.2 Ga by its Lu-Hf isochron age to 1.70?0.04 Ga of its Ar-Ar plateau ag e. However, recent in-situ U-Pb dating of phosphates in Kalahari 009 defined an old crystallization age of 4.35+/- 0.15 Ga. The authors su ggested that Kalahari 009 represents a cryptomaria basalt. In this r eport, we present Sm-Nd and Rb-Sr isotopic results for Kalahari 009, discuss the relationship of its age and isotopic characteristics to t hose of other L-24 VLT mare basalts and other probable cryptomaria ba salts represented by Apollo 14 aluminous mare basalts, and discuss it s petrogenesis.

  5. A petrogenetic model of basalts from the Northern Central Indian Ridge: 3-11°S

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, Dwijesh; Iyer, S.D.; Banerjee, R.; Misra, S.; Widdowson, M.

    ) and Y (~25 ppm) (Fig. 6). The nearly flat REE pattern [(Ce/Yb)N= 0.67?1.37] of the NCIR basalts (Fig. 7) suggest that these trace elements did not suffer any major fractionation during fractional crystallization of NCIR parent magma, except for a... progressive enrichment during fractionation (Figs. 7 d,e,f). 3. 5. Composition of parental magma of NCIR basalts It has been noted that the NCIR basalts show mixed incompatible trace element characters. Incompatible element ratios are highly variable...

  6. Contrasting geochemistry and metamorphism of pillow basalts in metamorphic complexes from Aysén, S. Chile

    Science.gov (United States)

    Hervé, F.; Aguirre, L.; Sepúlveda, V.; Morata, D.

    1999-07-01

    The geochemistry of pillow basalts from the Chonos Metamorphic Complex (CMC) and the Eastern Andes Metamorphic Complex of Aysén (EAMC) indicates contrasting tectonic environments for these basic lavas. They have E-MORB and continental alkaline affinities, respectively. The MORB-like basalts are metamorphosed in the pumpellyite-actinolite metamorphic facies, with mineral associations indicative of relatively high P/T metamorphism. The continental alkali basalts exhibit pumpellyite-chlorite assemblages developed in a low to intermediate P/T regime. These contrasting eruptive and metamorphic settings agree with recently established age differences between the complexes, and invalidate direct correlation between them.

  7. Rocket motors incorporating basalt fiber and nanoclay compositions and methods of insulating a rocket motor with the same

    Science.gov (United States)

    Gajiwala, Himansu M. (Inventor)

    2011-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber, basalt fibers, and nanoclay is disclosed. Further disclosed is an insulation composition that comprises polybenzimidazole fibers, basalt fibers, and nanoclay. The basalt fibers may be present in the insulation compositions in a range of from approximately 1% by weight to approximately 6% by weight of the total weight of the insulation composition. The nanoclay may be present in the insulation compositions in a range of from approximately 5% by weight to approximately 10% by weight of the total weight of the insulation composition. Rocket motors including the insulation compositions and methods of insulating a rocket motor are also disclosed.

  8. Basalt fiber and nanoclay compositions, articles incorporating the same, and methods of insulating a rocket motor with the same

    Science.gov (United States)

    Gajiwala, Himansu M. (Inventor)

    2010-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber, basalt fibers, and nanoclay is disclosed. Further disclosed is an insulation composition that comprises polybenzimidazole fibers, basalt fibers, and nanoclay. The basalt fibers may be present in the insulation compositions in a range of from approximately 1% by weight to approximately 6% by weight of the total weight of the insulation composition. The nanoclay may be present in the insulation compositions in a range of from approximately 5% by weight to approximately 10% by weight of the total weight of the insulation composition. Rocket motors including the insulation compositions and methods of insulating a rocket motor are also disclosed.

  9. Preliminary geochemical and physical testing of materials for plugging of man-made accesses to a repository in basalt

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.L.; Anttonen, G.J.; O' Rourke, J.E.; Allirot, D.

    1980-04-01

    The available data on environmental conditions (both natural and man-made) at the Hanford Site are sufficient for preconceptual plug system design. Results of the geochemical testing program indicate that preferred candidate plug materials are chemically nonreactive during laboratory tests that simulated some of the expected environmental conditions. Agitated, crushed-basalt samples and mixtures containing basalt were found to be self-cementing under the hydrothermal conditions. Materials considered most suitable for consideration in future test programs and preconceptual plug design are mixtures of natural materials (basalt, clay, glaciofluvial sand, gravel, and zeolite) and processed natural materials (portland cement Type V and grouts plus additives).

  10. Optical cavity resonator in an expanding universe

    Science.gov (United States)

    Kopeikin, Sergei M.

    2015-02-01

    We study the cosmological evolution of frequency of a standing electromagnetic wave in a resonant optical cavity placed to the expanding manifold described by the Robertson-Walker metric. Because of the Einstein principle of equivalence (EEP), one can find a local coordinate system (a local freely falling frame), in which spacetime is locally Minkowskian. However, due to the conformal nature of the Robertson-Walker metric the conventional transformation to the local inertial coordinates introduces ambiguity in the physical interpretation of the local time coordinate, . Therefore, contrary to a common-sense expectation, a straightforward implementation of EEP alone does not allow us to unambiguously decide whether atomic clocks based on quantum transitions of atoms, ticks at the same rate as the clocks based on electromagnetic modes of a cavity. To resolve this ambiguity we have to analyse the cavity rigidity and the oscillation of its electromagnetic modes in an expanding universe by employing the full machinery of the Maxwell equations irrespectively of the underlying theory of gravity. We proceed in this way and found out that the size of the cavity and the electromagnetic frequency experience an adiabatic drift in conformal (unphysical) coordinates as the universe expands in accordance with the Hubble law. We set up the oscillation equation for the resonant electromagnetic modes, solve it by the WKB approximation, and reduce the coordinate-dependent quantities to their counterparts measured by a local observer who counts time with atomic clock. The solution shows that there is a perfect mutual cancellation of the adiabatic drift of cavity's frequency by space transformation to local coordinates and the time counted by the clocks based on electromagnetic modes of cavity has the same rate as that of atomic clocks. We conclude that if general relativity is correct and the local expansion of space is isotropic there should be no cosmological drift of frequency of a

  11. The Expanding Marketplace for Applied Geophysics

    Science.gov (United States)

    Carlson, N.; Sirles, P.

    2012-12-01

    While the image of geophysics for the proverbial "layman" often seems limited to volcanoes and earthquakes, and to the geoscientist this image enlarges to include oil or minerals exploration and whole earth studies, there has been a steady increase in the application of geophysics into the realm of "daily life", such as real estate deals, highway infrastructure, and flood protection. This expansion of applications can be attributed to the improved economics from advances in equipment and interpretation. Traditional geophysical methods that at one time often only fit within the budgets of oil, gas, and minerals exploration programs can now be economically applied to much smaller scale needs like contaminant mapping, landfill delineation, and levee investigations. A real-world, economic example of this expanding marketplace is our company, which began very small and was aimed almost exclusively at the minerals exploration market. Most of our growth has been in the last 10 years, when we have expanded to five offices and a staff with almost 40 geoscientist degrees (21 in geophysics); much of this growth has been in the non-oil, non-minerals arenas. While much of our work still includes minerals exploration, other projects this year include wind-farm foundation studies, cavity detection above underground nuclear tests, landfill studies, acid mine drainage problems, and leaks in evaporation ponds. A methodology example of this expanding market is the induced polarization (IP) survey, once primarily used for minerals exploration, particularly large porphyry copper deposits, but now efficient enough to also use in environmental studies. The IP method has been particularly useful in delineating and characterizing old, poorly documented landfills, and recent research suggests it may also be useful in monitoring the accelerated biodegradation processes used in some cases to rehabilitate the sites. Compared to temperature monitoring systems, IP may be more useful in providing

  12. Scaling law deduced from impact-cratering experiments on basalt targets

    Science.gov (United States)

    Takagi, Y.; Hasegawa, S.; Suzuki, A.

    2014-07-01

    Since impact-cratering phenomena on planetary bodies were the key process which modified the surface topography and formed regolith layers, many experiments on non-cohesive materials (sand, glass beads) were performed. On the other hand, experiments on natural rocks were limited. Especially, experiments on basalt targets are rare, although basalt is the most common rocky material on planetary surfaces. The reason may be the difficulties of obtaining basalt samples suitable for cratering experiments. Recently, we obtained homogenous and crackless large basalt blocks. We performed systematic cratering experiments using the basalt targets. Experimental Procedure: Impact experiments were performed using a double stage light-gas (hydrogen) gun on the JAXA Sagamihara campus. Spherical projectiles of nylon, aluminum, stainless steel, and tungsten carbide were launched at velocities between 2400 and 6100 m/sec. The projectiles were 1.0 to 7.1 mm in diameter and 0.004 to 0.22 g in mass. The incidence angle was fixed at 90 degrees. The targets were rectangular blocks of Ukrainian basalt. The impact plane was a square with 20-cm sides. The thickness was 9 cm. Samples were cut out from a columnar block so that the impact plane might become perpendicular to the axis of the columnar joint. The mass was about 10.5 kg. The density was 2920 ± 10 kg/m^3 . Twenty eight shots were performed. Three-dimensional shapes of craters were measured by an X-Y stage with a laser displacement sensor (Keyence LK-H150). The interval between the measurement points was 200 micrometer. The volume, depth, and aperture area of the crater were calculated from the 3-D data using analytical software. Since the shapes of the formed craters are markedly asymmetrical, the diameter of the circle whose area is equal to the aperture area was taken as the crater diameter. Results: The diameter, depth, and the volume of the formed craters are normalized by the π parameters. Experimental conditions are also

  13. Chemical characterization, nano-particle mineralogy and particle size distribution of basalt dust wastes.

    Science.gov (United States)

    Dalmora, Adilson C; Ramos, Claudete G; Oliveira, Marcos L S; Teixeira, Elba C; Kautzmann, Rubens M; Taffarel, Silvio R; de Brum, Irineu A S; Silva, Luis F O

    2016-01-01

    Understanding the geochemistry of basalt alteration is central to the study of agriculture systems. Various nano-minerals play an important role in the mobilization of contaminants and their subsequent uptake by plants. We present a new analytical experimental approach in combination with an integrated analytical protocol designed to study basalt alteration processes. Recently, throughout the world, ultra-fine and nano-particles derived from basalt dust wastes (BDW) during "stonemeal" soil fertilizer application have been of great concern for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the Nova Prata mining district in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/Energy Dispersive Spectroscopy (EDS)/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM/EDS), and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO2, Al2O3, and Fe2O3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition, we have identified a number of trace metals such as Cd, Cu, Cr, and Zn, that are preferentially concentrated into the finer, inhalable, dust fraction and, thus, could present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical composition in

  14. Yaglom law in the expanding solar wind

    CERN Document Server

    Gogoberidze, G; Carbone, V

    2013-01-01

    We study the Yaglom law, which relates the mixed third order structure function to the average dissipation rate of turbulence, in a uniformly expanding solar wind by using the two scales expansion model of magnetohydrodynamic (MHD) turbulence. We show that due to the expansion of the solar wind two new terms appear in the Yaglom law. The first term is related to the decay of the turbulent energy by nonlinear interactions, whereas the second term is related to the non-zero cross-correlation of the Els\\"asser fields. Using magnetic field and plasma data from WIND and Helios 2 spacecrafts, we show that at lower frequencies in the inertial range of MHD turbulence the new terms become comparable to Yaglom's third order mixed moment, and therefore they cannot be neglected in the evaluation of the energy cascade rate in the solar wind.

  15. Expanding Technological Frames Towards Mediated Collaboration

    DEFF Research Database (Denmark)

    Bjørn, Pernille; Scupola, Ada; Fitzgerald, Brian

    2006-01-01

    This paper provides an in-depth analysis of technological and social factors leading to the successful adoption of groupware in a virtual team in educational setting. Drawing on a theoretical framework based on the concept of technological frames, we conducted an action research study to analyze...... the chronological sequence of events leading to groupware adoption. We argue that groupware adoption can be conceptualized as a three-step process of expanding and aligning individual technological frames towards groupware: The first step comprises activities facilitating participants in articulation and evaluation...... of their work practices and use of technology. Finally the third step includes participants' commitment and practical enactment of groupware. One of the key findings is that in groupware adoption the alignment of the individual technological frames requires articulation and re-evaluation of experienced...

  16. Expanding forensic science through forensic intelligence.

    Science.gov (United States)

    Ribaux, Olivier; Talbot Wright, Benjamin

    2014-12-01

    Research and Development ('R&D') in forensic science currently focuses on innovative technologies improving the efficiency of existing forensic processes, from the detection of marks and traces at the scene, to their presentation in Court. R&D approached from this perspective provides no response to doubts raised by recent criminological studies, which question the effective contribution of forensic science to crime reduction, and to policing in general. Traces (i.e. forensic case data), as remnants of criminal activity are collected and used in various forms of crime monitoring and investigation. The aforementioned doubts therefore need to be addressed by expressing how information is conveyed by traces in these processes. Modelling from this standpoint expands the scope of forensic science and provides new R&D opportunities. Twelve propositions for R&D are stated in order to pave the way.

  17. Rubella Seroprevalence Before Expanded Vaccination Program

    Directory of Open Access Journals (Sweden)

    Kenan Sener

    2007-10-01

    Full Text Available Altough rubella is usually a mild childhood disease, but when it occurs early in pregnancy are severe. In this study, seroprevalence of rubella antibodies have been invastegated in various age groups especially chilbearing age’s women before Expanded Vaccination Programme. IgM and IgG antibodies against rubella were tested by ELISA kits. Seropositivity of rubella IgG was 89,5% in chlidbearing age’s women. In Turkey, the vaccine has been on the market since 1989 but rubella vaccination is currently included in the national immunization programme. Hence, our results are important for comparison of the seroprevalence rates after national vaccination program. [TAF Prev Med Bull 2007; 6(5.000: 371-374

  18. Rubella Seroprevalence Before Expanded Vaccination Program

    Directory of Open Access Journals (Sweden)

    Kenan Sener

    2007-10-01

    Full Text Available Altough rubella is usually a mild childhood disease, but when it occurs early in pregnancy are severe. In this study, seroprevalence of rubella antibodies have been invastegated in various age groups especially chilbearing age’s women before Expanded Vaccination Programme. IgM and IgG antibodies against rubella were tested by ELISA kits. Seropositivity of rubella IgG was 89,5% in chlidbearing age’s women. In Turkey, the vaccine has been on the market since 1989 but rubella vaccination is currently included in the national immunization programme. Hence, our results are important for comparison of the seroprevalence rates after national vaccination program. [TAF Prev Med Bull. 2007; 6(5: 371-374

  19. Particles formation in an expanding plasma

    Energy Technology Data Exchange (ETDEWEB)

    Lescoute, E.; Hallo, L.; Chimier, B.; Tikhonchuk, V.T.; Stenz, C. [Bordeaux-1 Univ., CELIA, CNRS-CEA, 33 - Talence (France); Hebert, D.; Chevalier, J.M.; Rullier, J.L.; Palmier, S. [CEA Centre d' Etudes Scientifiques et Techniques d' Aquitaine, 33 - Le Barp (France)

    2009-08-15

    Interaction of a laser beam with a target generates a high velocity expanding plasma plume, solid debris and liquid nano- and micro-particles. They are produced from plasma recombination and vapor condensation and can be deposited on optical elements located nearby the target. Two distinct kinds of particles were observed depending on the temperature achieved in the plasma plume: large micrometer-size fragments for temperatures lower than the critical temperature, and very small nanometer-size particles for higher temperatures. The paper presents experimental observations of fragments and nano-particles in plasma plumes and a comparison with models. A good agreement has been found for nano-particle sizes and distributions. This simple modeling can also be used for nuclei production in the nanosecond time scale. Our estimates show that particle size can be correlated to laser wavelength and fluences.

  20. Homogeneous cosmology with aggressively expanding civilizations

    CERN Document Server

    Olson, S Jay

    2014-01-01

    In the context of a homogeneous universe, we note that the appearance of aggressively expanding advanced life is geometrically similar to the process of nucleation and bubble growth in a first-order cosmological phase transition. We exploit this similarity to describe the dynamics of life saturating the universe on a cosmic scale, adapting the phase transition model to incorporate probability distributions of expansion and resource consumption strategies. Through a series of numerical solutions covering several orders of magnitude in the input assumption parameters, the resulting cosmological model is used to address basic questions related to the intergalactic spreading of life, dealing with issues such as timescales, observability, competition between strategies, and first-mover advantage. Finally, we examine physical effects on the universe itself, such as reheating and the backreaction on the evolution of the scale factor, if such life is able to control and convert a significant fraction of the available...

  1. Heptaphyrins: Expanded porphyrins with seven heterocyclic rings

    Indian Academy of Sciences (India)

    Venkataramanarao G Anand; Simi K Pushpan; Sundararaman Venkatraman; Tavarekere K Chandrashekar

    2003-10-01

    Expanded porphyrins containing seven pyrrole/heterocyclic rings linked in a cyclic fashion are termed heptaphyrins. The number of -electrons in heptaphyrins depends on the number of meso carbon bridges used to link the heterocyclic rings, accordingly heptaphyrins with 28-electrons and 30 -electrons are reported to date. Both condensation reactions of the appropriate precursors and acid-catalysed oxidative coupling reactions have been utilized to synthesise the heptaphyrins. The 30 heptaphyrins exhibit rich structural diversity where some of the heterocyclic rings in the macrocycle undergo a 180° ring flipping. An overview of the synthetic methods employed for the synthesis of heptaphyrins, their spectroscopic properties, structural behaviour and aromatic properties are highlighted in this paper.

  2. Helical chirality induction of expanded porphyrin analogues

    Indian Academy of Sciences (India)

    Jun-Ichiro Setsune

    2012-11-01

    Expanded porphyrin analogues with unique figure-eight conformation were prepared by way of useful pyrrole intermediates such as bis(azafulvene)s and 2-borylpyrrole. Supramolecular chirogenesis of cyclooctapyrrole O1 with 32-cycloconjugation was successfully applied to determine absolute configuration of chiral carboxylic acids. Dinuclear CuII complex of cyclooctapyrrole O2 with interrupted -conjugation was resolved by HPLC into enantiomers and their helical handedness was determined by theoretical simulation of their CD spectral pattern. Enantioselective induction of helicity in the metal helicate formation in the presence of a chiral promoter was demonstrated by using ()-(+)-1-(1-phenyl)ethylamine that favoured , helicity. Dinuclear CoII complexes of cyclotetrapyrroletetrapyridine O3 were found to be substitution labile and pick up amino acid anions in water. Those amino acid complexes of O3Co2 were rendered to adopt a particular unidirectional helical conformation preferentially depending on the ligated amino acid anion.

  3. Trichorhinophalangeal syndrome II, expanding the clinical spectrum

    Directory of Open Access Journals (Sweden)

    Rabah M. Shawky

    2015-01-01

    Full Text Available We report a 4.5 year old Egyptian male child, fourth in the order of birth of healthy remote consanguineous parents. He has typical facial as well as skeletal features of Trichorhinophalangeal syndrome (TRPS II. The facial features included bilateral downward slanting palpebral fissures, bulbous nose, long filtrum, retromicrognathia, sparse hair in the scalp and thick eyebrows. The skeletal features included retarded bone age, cone shaped epiphyses of the phalanges and multiple exostoses. The patient has also growth retardation, moderate mental retardation and hyperlaxity of the right knee joint. However our patient has some features not reported in TRPS II patients. These included bilateral partial ptosis, long eye lashes, preauricular skin tag, short 2nd right finger, short metacarpals of both thumbs. So we have to expand the clinical spectrum. Karyotype demonstrated 46,XY,del 8(q23.3-q24.1.

  4. Expanding Greenland’s Glacial Record

    DEFF Research Database (Denmark)

    Bjørk, Anders Anker

    Mass loss from the Greenland Ice Sheet and adjecent glaciers and ice caps has accelerated within the last decades, and these changes are accurately observed using a variety of different data products. However, the observational era is relatively short offering little insight into past dynamics. O...... the entire 20th century show rapid and widespread responses to climate change. On a longer time-scale is the Holocene history of Helheim Glacier reconstructed using evidence of glacial presence accumulated in lake sediments....... On order to expand the glacial history of Greenland, this thesis explores physical and geological archives for evidence of the glaciers’ past response to climatic variations. Using aerial photographs, the dynamic history of the Greenland Ice Sheet is extended back to 1900 C.E. Glacier changes covering...

  5. Gravitational wave memory in an expanding universe

    Science.gov (United States)

    Tolish, Alexander; Wald, Robert

    2016-03-01

    We investigate the gravitational wave memory effect in an expanding FLRW spacetime. We find that if the gravitational field is decomposed into gauge-invariant scalar, vector, and tensor modes after the fashion of Bardeen, only the tensor mode gives rise to memory, and this memory can be calculated using the retarded Green's function associated with the tensor wave equation. If locally similar radiation source events occur on flat and FLRW backgrounds, we find that the resulting memories will differ only by a redshift factor, and we explore whether or not this factor depends on the expansion history of the FLRW universe. We compare our results to related work by Bieri, Garfinkle, and Yau.

  6. Expanding Policy Imagination in Political Economy

    DEFF Research Database (Denmark)

    Seabrooke, Leonard

    2006-01-01

    be implemented. Historical sociology provides a way to generate information about contextual constellations through two "tonics": intentional rationality and social mechanisms. With the assistance of these tonics, historical sociology widens political economy's policy imagination.......Much of the literature in political economy seeks to capture an essential insight into the evolution of political and economic systems to provide a foundation for policy advice. This article suggests that attempts to nut out the kernels of change often restrict rather than expand policy imagination...... capacity to see political, social, and economic changes that do not conform to conventional theories, as well as distorting our understanding of how the contemporary world works. What policymakers want, more than prediction or recitation of conventional theories, is context to understand how policy can...

  7. Henry Norris Russell and the Expanding Universe

    CERN Document Server

    DeVorkin, David H

    2013-01-01

    Henry Norris Russell, one of the most influential American astronomers of the first half of the 20th Century, had a special place in his heart for the Lowell Observatory. Although privately critical of the founder for his pronouncements about life on Mars and the superiority of the Mars Hill observing site, he always supported the Observatory in public and professional circles. He staunchly supported Tombaugh's detection of a planet as leading from Lowell's prediction, and always promoted V. M. Slipher's spectroscopic investigations of planetary and stellar phenomena. But how did he react to Slipher's puzzling detection of the extreme radial velocities of spiral nebulae starting in 1912, and how did he regard the extension and interpretation of those observations by Hubble and others in following decades? Here we describe the arc of Russell's reactions, dating from Slipher's first detection, as an indicator of how mainstream stellar astronomers reacted to the concept of an expanding universe.

  8. Cosmic strings in an expanding spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Stein-Schabes, J.A.; Burd, A.B.

    1987-04-01

    We investigate the stability of a static, infinitely long and straight vacuum string solution under inhomogeneous axisymmetric time-dependent perturbations. We find it to be perturbatively stable. We further extend our work by finding a string solutions in an expanding Universe. The back reaction of the string on the gravitational field has been ignored. The background is assumed to be a Friedman-Robertson-Walker (FRW) cosmology. By numerically integrating the field equations in a radiation and matter dominated models, we discover oscillatory solutions. The possible damping of these oscillations is discussed. For late times the solution becomes identical to the static one studied in the first part of the paper. 19 refs., 8 figs.

  9. Roots Air Management System with Integrated Expander

    Energy Technology Data Exchange (ETDEWEB)

    Stretch, Dale [Eaton Corporation, Menomonee Falls, WI (United States); Wright, Brad [Eaton Corporation, Menomonee Falls, WI (United States); Fortini, Matt [Eaton Corporation, Menomonee Falls, WI (United States); Fink, Neal [Ballard Power Systems, Burnaby, BC (Canada); Ramadan, Bassem [Kettering Univ., Flint, MI (United States); Eybergen, William [Eaton Corporation, Menomonee Falls, WI (United States)

    2016-07-06

    PEM fuel cells remain an emerging technology in the vehicle market with several cost and reliability challenges that must be overcome in order to increase market penetration and acceptance. The DOE has identified the lack of a cost effective, reliable, and efficient air supply system that meets the operational requirements of a pressurized PEM 80kW fuel cell as one of the major technological barriers that must be overcome. This project leveraged Roots positive displacement development advancements and demonstrated an efficient and low cost fuel cell air management system. Eaton built upon its P-Series Roots positive displacement design and shifted the peak efficiency making it ideal for use on an 80kW PEM stack. Advantages to this solution include: • Lower speed of the Roots device eliminates complex air bearings present on other systems. • Broad efficiency map of Roots based systems provides an overall higher drive cycle fuel economy. • Core Roots technology has been developed and validated for other transportation applications. Eaton modified their novel R340 Twin Vortices Series (TVS) Roots-type supercharger for this application. The TVS delivers more power and better fuel economy in a smaller package as compared to other supercharger technologies. By properly matching the helix angle with the rotor’s physical aspect ratio, the supercharger’s peak efficiency can be moved to the operating range where it is most beneficial for the application. The compressor was designed to meet the 90 g/s flow at a pressure ratio of 2.5, similar in design to the P-Series 340. A net shape plastic expander housing with integrated motor and compressor was developed to significantly reduce the cost of the system. This integrated design reduced part count by incorporating an overhung expander and motor rotors into the design such that only four bearings and two shafts were utilized.

  10. Role of mechanical erosion in controlling the effusion rate of basaltic eruptions

    Science.gov (United States)

    Piombo, Antonello; Tallarico, Andrea; Dragoni, Michele

    2016-09-01

    In many basaltic eruptions, observations show that the effusion rate of magma has a typical dependence on time: the effusion rate curves show first a period of increasing and later a decreasing phase by a maximum value. We present a model to explain this behavior by the emptying of a magma reservoir through a vertical cylindrical conduit with elliptical cross section, coupled with the its widening due to mechanical erosion, produced by the magma flow. The model can reproduce the observed dependence on time of effusion rate in basaltic eruptions. Eruption duration and the maximum value of effusion rate depend on the size of magma chamber, on lava viscosity and strongly on erosion rate per unit traction.

  11. Lithium tracer-diffusion in an alkali-basaltic melt — An ion-microprobe determination

    Science.gov (United States)

    Lowry, R. K.; Reed, S. J. B.; Nolan, J.; Henderson, P.; Long, J. V. P.

    1981-03-01

    An ion-microprobe-based technique has been used to measure lithium tracer-diffusion coefficients ( D Li) in an alkali-basaltic melt at 1300, 1350 and 1400°C. The results can be expressed in the form: D Li=7.5 ×10 -2exp(-27,600/RT)cm 2S -1 The results show significantly faster diffusion rates than those previously recorded for other monovalent, divalent and trivalent cations in a tholeiitic melt. Consequently, diffusive transport of ions acting over a given time in a basaltic melt can produce a wider range of transport distance values than hitherto supposed. Hence, it is concluded that great care should be exercised when applying diffusion data to petrological problems.

  12. Primitive, high-Mg basaltic andesites: direct melts of the shallow, hot, wet mantle

    Science.gov (United States)

    Andrews, A.; Grove, T. L.

    2013-12-01

    Direct mantle melts are rare in subduction zone settings. Such melts are identified by Mg #s (Mg # = Mg / (Mg+Fe)) greater than ~0.73, indicating chemical equilibrium with Fo90 mantle olivine. Most of these primitive arc melts are basaltic, characterized by SiO2 contents of ~48-50 wt % and MgO contents ranging from 8-10 wt %. However, primitive basaltic andesites with mantle-equilibrated Mg #s have also been found at subduction zones worldwide. These basaltic andesites have higher SiO2 contents (53-58 wt %) than typical primitive basalts as well as high MgO (8-10 wt %). Because these rocks have high SiO2 contents and yet retain evidence for chemical equilibrium with the mantle (Mg #s), their petrogenesis has sparked intense debate as researchers have tried to discern how these samples fit into the paradigm of mantle melting at subduction zones. Through an understanding of the conditions and processes that produce the SiO2 enrichment in these rocks, we also aim to understand the role of these melts in producing the observed andesitic compositional characteristics of the continental crust. To understand the petrogenesis of primitive, high-Mg basaltic andesites, this study investigates the experimental melts of undepleted mantle peridotite plus a slab component (Na-2O + K2O) from 1,205-1,470°C at 1.0-2.0 GPa under water-undersaturated conditions (0-5 wt % H2O). At 1.0 and 1.2 GPa, the experimental melts reproduce the compositions of natural primitive, high-Mg basaltic andesites in all major elements (SiO2, TiO2, Al2O3, FeO, MnO, MgO, and Na2O+K2O) except CaO. CaO contents are higher than the range of the natural samples by ~2 wt % at the highest silica contents of the experiments (54-56 wt% SiO2). This suggests that at 1.0-1.2 GPa, a higher percent of melting (30-35 %) with 3-5 wt % H2O is required to drive the chemical compositions of the experiments toward the representative compositions of the natural rocks. The experimental melts also show that mantle-wall rock

  13. Strength and Deformability of Fiber Reinforced Cement Paste on the Basis of Basalt Fiber

    Directory of Open Access Journals (Sweden)

    Yury Barabanshchikov

    2016-01-01

    Full Text Available The research object of the paper is cement paste with the particulate reinforcement of basalt fiber. Regardless of fibers’ length at the same fiber cement mix workability and cement consumption equality compressive solidity of the specimens is reduced with increasing fiber content. This is due to the necessity to increase the water-cement ratio to obtain a given workability. The flexural stability of the specimens with increasing fiber content increments in the same conditions. There is an optimum value of the fibers’ dosage. That is why stability has a maximum when crooking. The basaltic fiber particulate reinforcement usage can abruptly increase the cement paste level limiting extensibility, which is extremely important in terms of crack resistance.

  14. Evidence for microbial carbon and sulfur cycling in deeply buried ridge flank basalt.

    Science.gov (United States)

    Lever, Mark A; Rouxel, Olivier; Alt, Jeffrey C; Shimizu, Nobumichi; Ono, Shuhei; Coggon, Rosalind M; Shanks, Wayne C; Lapham, Laura; Elvert, Marcus; Prieto-Mollar, Xavier; Hinrichs, Kai-Uwe; Inagaki, Fumio; Teske, Andreas

    2013-03-15

    Sediment-covered basalt on the flanks of mid-ocean ridges constitutes most of Earth's oceanic crust, but the composition and metabolic function of its microbial ecosystem are largely unknown. By drilling into 3.5-million-year-old subseafloor basalt, we demonstrated the presence of methane- and sulfur-cycling microbes on the eastern flank of the Juan de Fuca Ridge. Depth horizons with functional genes indicative of methane-cycling and sulfate-reducing microorganisms are enriched in solid-phase sulfur and total organic carbon, host δ(13)C- and δ(34)S-isotopic values with a biological imprint, and show clear signs of microbial activity when incubated in the laboratory. Downcore changes in carbon and sulfur cycling show discrete geochemical intervals with chemoautotrophic δ(13)C signatures locally attenuated by heterotrophic metabolism.

  15. BASALTIC ASTEROIDS: A NEW LOOK ON THE DIFFERENTIATION PROCESS IN THE MAIN BELT

    Directory of Open Access Journals (Sweden)

    D. Lazzaro

    2009-01-01

    Full Text Available Although asteroid (4 Vesta is the only large object in the Main Belt which shows an almost intact basaltic crust, an increasingly large number of small asteroids with a similar surface composition have been discovered in the last years. All these objects, classi ed as V-type in the diverse taxonomies, have a surface composition similar to that of the Howardites, Eucrites, and Diogenites meteorites, known as HED. In this paper we review the new ndings on basaltic asteroids, and on the HED meteorites, and discuss how these reinforce the idea that di erentiation was quite common in the Main Belt early stages of formation, in contrast to the classical scenario which considers the formation of just one large di erentiated body, (4 Vesta.

  16. Energy and Carbon Flow: Comparing ultramafic- and basalt-hosted vents

    Science.gov (United States)

    Perner, M.; Bach, W.; Seifert, R.; Strauss, H.; Laroche, J.

    2010-12-01

    In deep-sea vent habitats hydrothermal fluids provide the grounds for life by supplying reduced inorganic compounds (e.g. H2, sulfide). Chemolithoautotrophs can oxidize these substrates hereby yielding energy, which can then be used to fuel autotrophic CO2 fixation. Depending on the type of host rocks (and the degree of admixed ambient seawater) the availability of inorganic electron donors can vary considerably. While in ultramafic-hosted vents H2 levels are high and H2-oxidizing metabolisms are thought to dominate, in basalt-hosted vents, H2 is much lower and microbial sulfide oxidation is considered to prevail [1, 2]. We have investigated the effect of H2 and sulfide availability on the microbial community of distinct H2-rich and H2-poor vent sites along the Mid-Atlantic Ridge. Hydrothermally influenced samples were collected from the H2-rich ultramafic-hosted Logatchev field (15°N) and the comparatively H2-poor basalt-hosted vents from 5°S and 9°S. We conducted catabolic energy calculations to estimate the potential of various electron donors to function as microbial energy sources. We performed incubation experiments with hydrothermal fluids amended with H2 or sulfide and radioactively labelled bicarbonate and determined H2 and sulfide consumption and carbon incorporation rates. We constructed metagenomic libraries for sequence-based screening of genes encoding key enzymes for H2 uptake (NiFe uptake hydrogenases, group 1), sulfide oxidation (sulfide quinone oxidoreductase, sqr) and CO2 fixation pathways (RubisCOs of the Calvin cycle [CBB] and beta-subunit of the ATP citrate lyase of the reductive tricarboxylic acid cycle [rTCA]). We evaluated parts of the metagenomes from basalt-hosted sites by pyrosequencing. Based on our incubation experiments - under the conditions applied - we could not confirm that generally H2 consumption rates and biomass syntheses in fluids derived from ultramafic-hosted locations are significantly enhanced over those from basalt

  17. Paraná-Etendeka basalts in Misiones, Argentina; characterization and petrogenetic inferences

    Science.gov (United States)

    Rämö, O. T.; Heikkilä, P. A.

    2013-12-01

    The Early Cretaceous (ca. 130 Ma) Paraná-Etendeka flood basalts constitute one of the major Phanerozoic LIP sequences with an original volume probably in excess of 2.3 Mkm3.The bulk of this volcanic system is preserved in South America (Brazil, Uruguay, Paraguay, Argentina), where it manifests the onset of South Atlantic opening at present 25 degrees Southern Latitude. The sequence is overwhelmingly basaltic (ca. 90%), but also includes contemporaneous silicic volcanic rocks. Known as the Serra Geral Suite (e.g., Bellieni et al., 1984), it fills the Paraná Basin with a northward deepening strata of lavas with a maximum thickness of ca. 1500 m. We have collected and examined basalt samples from the west-central part (western flank) of the Paraná Basin in Misiones State, northeastern Argentina (54-55 degrees Western Longitude), where the estimated thickness of the basalt succession decreases from ca. 700 m in the east to ca. 300 m in the west. The examined samples are massive, aphyric (or microphyric with plagioclase and altered olivine microphenocrysts), and geochemically relatively evolved (Mg number 50-35) basalts and basaltic andesites. Their MgO values are between 6 and 3.7 wt.% and Ni content is relatively low (65-20 ppm). Incompatible trace element values increase with increasing fractionation (decreasing Mg number), e.g., Zr from 135 to 290 ppm, Ce from 45 to 105 ppm, Nd from 20 to 50 ppm, Sm from 5 to 11 ppm, Ba from 280 to 600 ppm, and Y from 25 to 50 ppm. In terms of Ti, the samples fall into two groups (1.9-2.3 and ca. 3.8 wt.% TiO2). These values conform, respectively, to the high-Ti, high-Ti/Y Paranapanema and Pitanga magma types of Peate et al. (1992) that govern the northern half of the Paraná basalt succession. Initial Nd and Sr isotope compositions of the two groups are remarkably uniform. Our analyzed ten samples have an average initial (at 134.6 Ma) epsilon-Nd value of -4.2 × 0.3 (1 SD) and an average initial 87Sr/86Sr of 0.70570 × 0

  18. Trace element abundances in megacrysts and their host basalts - Constraints on partition coefficients and megacryst genesis

    Science.gov (United States)

    Irving, A. J.; Frey, F. A.

    1984-01-01

    Rare earth and other trace element abundances are determined in megacrysts of clinopyroxene, orthopyroxene, amphibole, mica, anorthoclase, apatite and zircon, as well as their host basalts, in an effort to gather data on mineral/melt trace element partitioning during the high pressure petrogenesis of basic rocks. Phase equilibria, major element partitioning and isotopic ratio considerations indicate that while most of the pyroxene and amphibole megacrysts may have been in equilibrium with their host magmas at high pressures, mica, anorthoclase, apatite, and zircon megacrysts are unlikely to have formed in equilibrium with their host basalts. It is instead concluded that they were precipitated from more evolved magmas, and have been mixed into their present hosts.

  19. 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.

  20. Imogolite and allophane formed in saprolite of basalt on Maui, Hawaii

    Science.gov (United States)

    Wada, K.; Henmi, T.; Yoshinaga, N.; Patterson, S.H.

    1972-01-01

    Inorganic gel and allophane collected from basaltic saprolite on Maui, Hawaii, and studied by Patterson in 1964 were reexamined. The main constituent of the gel is imogolite, and gibbsite and allophane are the minor constituents. Electron and X-ray diffraction patterns, DTA curve, and an infrared spectrum of the gel are characteristic of imogolite. The allophane is virtually noncrystalline to X-rays but contains a small amount of imogolite in relatively short threads. High-resolution electron micrographs indicate differences in structural organization between allophane and imogolite and suggest crystallization of imogolite from allophane. The occurrence of imogolite as a weathering product has been reported in many localities from pyroclastic materials but not from massive rocks. Probably the exceptionally high rainfall, excellent subsurface permeability of the weathered material, and the low pH and high organic content of the leaching solution provide favorable conditions for formation of imogolite from basalt on Maui. ?? 1972.

  1. A minimum UPb age for Siberian flood-basalt volcanism

    Science.gov (United States)

    Kamo, S. L.; Czamanske, G. K.; Krogh, T. E.

    1996-09-01

    Establishing an accurate and precise age for Siberian flood-basalt volcanism is of great importance in evaluating causes for the unequaled mass extinction of flora and fauna at the Permian-Triassic boundary. We report a new, minimum UPb age obtained from zircon and baddeleyite from the mineralized Noril'sk I intrusion that cuts the lower third of this rapidly deposited, 3500-m-thick volcanic sequence near Noril'sk. This 251.2 ± 0.3 (2σ) Ma age is within analytical error of the SHRIMP UPb age for zircon from the Permian-Triassic boundary at Meishan, South China [251.1 ± 3.6 Ma (2σ)], and confirms Siberian basaltic volcanism as a possible contributor to the mass extinction.

  2. A minimum U-Pb age for Siberian flood-basalt volcanism

    Science.gov (United States)

    Kamo, S.L.; Czamanske, G.K.; Krogh, T.E.

    1996-01-01

    Establishing an accurate and precise age for Siberian flood-basalt volcanism is of great importance in evaluating causes for the unequaled mass extinction of flora and fauna at the Permian-Triassic boundary. We report a new, minimum U-Pb age obtained from zircon and baddeleyite from the mineralized Noril'sk I intrusion that cuts the lower third of this rapidly deposited, 3500-m-thick volcanic sequence near Noril'sk. This 251.2 ?? 0.3 (2??) Ma age is within analytical error of the SHRIMP U-Pb age for zircon from the Permian-Triassic boundary at Meishan, South China [251.1 ?? 3.6 Ma (2??)], and confirms Siberian basaltic volcanism as a possible contributor to the mass extinction.

  3. Basalt Waste Isolation Project technical program evaluation process: A criteria-based method

    Science.gov (United States)

    Babad, H.; Evans, G. C.; Wolfe, B. A.

    The need to objectively evaluate the progress being made by the Basalt Waste Isolation Project (BWIP) toward establishing the feasibility of siting a nuclear waste repository in basalt (NWRB) mandates a process for evaluating the technical work of the project. To assist BWIP management in the evaluation process, the Systems Department staff has developed a BWIP Technical Program Evaluation Process (TPEP). The basic process relates progress on project technical work to the SWIP Functional and System Performance Criteria as defined in National Waste Terminal Storage (MWTS) Criteria Documents. The benefits of the TPEP to BWIP and future plans for TPEP are discussed. During fiscal year (FY) 1982, TPEP will be further formalized and further applied to the review of BWIP technical activities.

  4. Basalt Waste Isolation Project Technical Program Evaluation Process: a criteria-based method

    Energy Technology Data Exchange (ETDEWEB)

    Babad, H.; Evans, G.C.; Wolfe, B.A.

    1982-01-01

    The need to objectively evaluate the progress being made by the Basalt Waste Isolation Project (BWIP) toward establishing the feasibility of siting a nuclear waste repository in basalt (NWRB) mandates a process for evaluating the technical work of the project. To assist BWIP management in the evaluation process, the Systems Department staff has developed a BWIP Technical Program Evaluation Process (TPEP). The basic process relates progress on project technical work to the SWIP Functional and System Performance Criteria as defined in National Waste Terminal Storage (MWTS) Criteria Documents. The benefits of the TPEP to BWIP and future plans for TPEP are discussed. During fiscal year (FY) 1982, TPEP wll be further formalized and further applied to the review of BWIP technical activities.

  5. Some thoughts on the origin of lunar ANT-KREEP and mare basalts

    Science.gov (United States)

    Wakita, H.; Laul, J. C.; Schmitt, R. A.

    1975-01-01

    It is suggested that a series of ANT (anorthosite-norite-troctolite)-KREEP type rocks and the source material for mare basalts sampled by Apollo 11, 12, 15, and 17 may have been derived from a common magmatic differentiation. This differentiation is studied on the basis of a model which proposes that, in the early history of the moon, extensive melting occurred in the outer lunar shell and a magma layer of 100-200 km was formed. The presence of a residual liquid which has not yet been sampled is suspected between high-K KREEP and the Apollo 11 basalt materials. This residual liquid would have a FeO/MgO ratio greater than one and would be significantly enriched in apatite, zircon, K-feldspar, and ilmenite minerals.

  6. Basalt fiber insulating material with a mineral binding agent for industrial use

    Science.gov (United States)

    Drozdyuk, T.; Aizenshtadt, A.; Tutygin, A.; Frolova, M.

    2016-04-01

    The paper considers a possibility of using mining industry waste as a binding agent for heat insulating material on the basis of basalt fiber. The main objective of the research is to produce a heat-insulating material to be applied in machine building in high-temperature environments. After synthetic binder having been replaced by a mineral one, an environmentally sound thermal insulating material having desirable heat-protecting ability and not failing when exposed to high temperatures was obtained.

  7. A Fungal-Prokaryotic Consortium at the Basalt-Zeolite Interface in Subseafloor Igneous Crust.

    Directory of Open Access Journals (Sweden)

    Magnus Ivarsson

    Full Text Available We have after half a century of coordinated scientific drilling gained insight into Earth´s largest microbial habitat, the subseafloor igneous crust, but still lack substantial understanding regarding its abundance, diversity and ecology. Here we describe a fossilized microbial consortium of prokaryotes and fungi at the basalt-zeolite interface of fractured subseafloor basalts from a depth of 240 m below seafloor (mbsf. The microbial consortium and its relationship with the surrounding physical environment are revealed by synchrotron-based X-ray tomographic microscopy (SRXTM, environmental scanning electron microscopy (ESEM, and Raman spectroscopy. The base of the consortium is represented by microstromatolites-remains of bacterial communities that oxidized reduced iron directly from the basalt. The microstromatolites and the surrounding basalt were overlaid by fungal cells and hyphae. The consortium was overgrown by hydrothermally formed zeolites but remained alive and active during this event. After its formation, fungal hyphae bored in the zeolite, producing millimetre-long tunnels through the mineral substrate. The dissolution could either serve to extract metals like Ca, Na and K essential for fungal growth and metabolism, or be a response to environmental stress owing to the mineral overgrowth. Our results show how microbial life may be maintained in a nutrient-poor and extreme environment by close ecological interplay and reveal an effective strategy for nutrient extraction from minerals. The prokaryotic portion of the consortium served as a carbon source for the eukaryotic portion. Such an approach may be a prerequisite for prokaryotic-eukaryotic colonisation of, and persistence in, subseafloor igneous crust.

  8. Indigenous nitrogen in the Moon: Constraints from coupled nitrogen-noble gas analyses of mare basalts

    Science.gov (United States)

    Füri, Evelyn; Barry, Peter H.; Taylor, Lawrence A.; Marty, Bernard

    2015-12-01

    Nitrogen and noble gas (Ne-Ar) abundances and isotope ratios, determined by step-wise CO2 laser-extraction, static-mass spectrometry analysis, are reported for bulk fragments and mineral separates of ten lunar mare basalts (10020, 10057, 12008, 14053, 15555, 70255, 71557, 71576, 74255, 74275), one highland breccia (14321), and one ferroan anorthosite (15414). The mare basalt sub-samples 10057,183 and 71576,12 contain a large amount of solar noble gases, whereas neon and argon in all other samples are purely cosmogenic, as shown by their 21Ne/22Ne ratios of ≈0.85 and 36Ar/38Ar ratios of ≈0.65. The solar-gas-free basalts contain a two-component mixture of cosmogenic 15N and indigenous nitrogen (Earth's primordial mantle or an enstatite chondrite-like impactor. While the lowest δ15 N values allow for nitrogen trapped in the Moon's interior to be inherited from the proto-Earth and/or the impactor, the more 15N-enriched compositions require that carbonaceous chondrites provided nitrogen to the lunar magma ocean prior to the solidification of the crust. Since nitrogen can efficiently be incorporated into mafic minerals (olivine, pyroxene) under oxygen fugacities close to or below the iron-wustite buffer (Li et al., 2013), the mare basalt source region is likely characterized by a high nitrogen storage capacity. In contrast, anorthosite 15414 shows no traces of indigenous nitrogen, suggesting that nitrogen was not efficiently incorporated into the lunar crust during magma ocean differentiation.

  9. Potential fossil endoliths in vesicular pillow basalt, Coral Patch Seamount, eastern North Atlantic Ocean.

    Science.gov (United States)

    Cavalazzi, Barbara; Westall, Frances; Cady, Sherry L; Barbieri, Roberto; Foucher, Frédéric

    2011-09-01

    The chilled rinds of pillow basalt from the Ampère-Coral Patch Seamounts in the eastern North Atlantic were studied as a potential habitat of microbial life. A variety of putative biogenic structures, which include filamentous and spherical microfossil-like structures, were detected in K-phillipsite-filled amygdules within the chilled rinds. The filamentous structures (∼2.5 μm in diameter) occur as K-phillipsite tubules surrounded by an Fe-oxyhydroxide (lepidocrocite) rich membranous structure, whereas the spherical structures (from 4 to 2 μm in diameter) are associated with Ti oxide (anatase) and carbonaceous matter. Several lines of evidence indicate that the microfossil-like structures in the pillow basalt are the fossilized remains of microorganisms. Possible biosignatures include the carbonaceous nature of the spherical structures, their size distributions and morphology, the presence and distribution of native fluorescence, mineralogical and chemical composition, and environmental context. When taken together, the suite of possible biosignatures supports the hypothesis that the fossil-like structures are of biological origin. The vesicular microhabitat of the rock matrix is likely to have hosted a cryptoendolithic microbial community. This study documents a variety of evidence for past microbial life in a hitherto poorly investigated and underestimated microenvironment, as represented by the amygdules in the chilled pillow basalt rinds. This kind of endolithic volcanic habitat would have been common on the early rocky planets in our Solar System, such as Earth and Mars. This study provides a framework for evaluating traces of past life in vesicular pillow basalts, regardless of whether they occur on early Earth or Mars.

  10. Striking Local Distinctions in Basaltic Melts within Nicaraguan Cross-arc Lineaments

    Science.gov (United States)

    Her, X.; Walker, J. A.; Roggensack, K.

    2015-12-01

    The Nejapa-Miraflores (NM) and Granada (G) lineaments which cut across the Central American volcanic front (CAVF) host numerous monogenetic vents which have erupted diverse basaltic magmas (e.g., Walker, 1984). As previously shown by Walker (1984), the basaltic magmas loosely fall into two groups: a high Ti, low K group which are reminiscent of MORB or BABB; and a low Ti, high K group which are more typical of subduction zones worldwide. Major element data obtained from over 200 olivine-hosted melt inclusions found within NM and G tephras from six separate monogenetic vents confirm this unusual compositional dichotomy. Melt inclusions from four of the six monogenetic vents are exclusively high- or low-Ti, while two of the volcanoes have both high- and low-Ti melt inclusions. New volatile and trace element data on over 40 of the NM and G melt inclusions has yielded additional compositional distinctions between the high- and low-Ti groups. Least degassed high-Ti melts tend to have lower water contents than their low-Ti counterparts. The high-Ti Inclusions also have lower concentrations of U, Th, Pb, Ba and Cs and lower La/Yb ratios. In addition, there are subtle HFSE variations between the two types of basalts. The overall geochemical differences between the high- and low-Ti groups suggest that the mantle wedge source of the latter contains a greater slab-derived (hemipelagic) sediment melt component than the former linked to a larger flux of hydrous fluids from deeper in the subducting Cocos plate. What is particularly significant is that the contrasting mafic emanations from these monogenetic volcano lineaments demonstrate that transport of fluids, volatiles and basaltic melts in subduction zones can be quite variable and complex on a very localized scale.

  11. Detection of sub-basaltic sediments by a multi-parametric joint inversion approach

    Indian Academy of Sciences (India)

    Ajay Manglik; Saurabh K Verma; K H Singh

    2009-10-01

    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 of sediments difficult due to the low velocity layer problem.Electrical and electromagnetic methods have been used in such scenarios because of the good electrical conductivity contrast between basalts and underlying sediments.However,mapping of the target sediments becomes difficult when the layer is thin as the data errors due to inherent noise lead to equivalent solutions.To tackle such difficult situations,a joint inversion scheme incorporating seismic reflection and refraction, magnetotelluric and deep electrical resistivity datasets is presented. Efficacy of the scheme is tested for a model comprising a thin sedimentary layer sandwiched between a thick basalt cover and a granitic basement.The results indicate that the parameters of the target sedimentary layer are either poorly resolved or equivalent solutions are obtained by the inversion of individual datasets. Joint inversions of seismic reflection (RFLS)and refraction (RFRS),or DC and MT dataset pairs provide improved results and the range of equivalent solutions is narrowed down.Combination of any three of the above datasets leads to further narrowing of this range and improvements in mean model estimates.Joint inversion incorporating all the datasets is found to yield good estimates of the structure.Resolution analysis is carried out to appraise estimates of various model parameters obtained by jointly inverting different combinations of datasets.

  12. Performance evaluation of a reverse-gradient artificial recharge system in basalt aquifers of Maharashtra, India

    Science.gov (United States)

    Bhusari, Vijay; Katpatal, Y. B.; Kundal, Pradeep

    2016-12-01

    Drinking water scarcity in rural parts of central India in basaltic terrain is common. Most of the rural population depends on groundwater sources located in the fractured and weathered zone of the basaltic aquifers. Long-term indiscriminate withdrawal has caused an alarming rate of depletion of groundwater levels in both pre- and post-monsoon periods. The aquifer is not replenished through precipitation under natural conditions. To overcome this situation, an innovative artificial recharge system, called the reverse-gradient recharge system (RGRS), was implemented in seven villages of Wardha district of Maharashtra. The study described here presents a comparative analysis of recharge systems constructed in the year 2012 downstream of dug-well locations in these seven villages. The post-project comparative analysis reveals that the area of influence (AOI) of the groundwater recharge system, within which increases in groundwater levels and yield are observed, is directly related to the specific yield, thickness of the weathered and fractured zone, porosity, and transmissivity of the aquifer, showing high correlation coefficients of 0.92, 0.88, 0.85 and 0.83, respectively. The study indicates that the RGRS is most effective in vesicular weathered and fractured basalt, recording a maximum increase in well yield of 65-82 m3/day, while a minimum increase in yield of 15-30 m3/day was observed in weathered vesicular basalt. The comparative analysis thus identifies the controlling factors which facilitate groundwater recharge through the proposed RGRS. After implementation of these projects, the groundwater availability in these villages increased significantly, solving their drinking water problems.

  13. High water contents in basaltic melt inclusions from Arenal volcano, Costa Rica

    Science.gov (United States)

    Wade, J. A.; Plank, T.; Hauri, E. H.; Melson, W. G.; Soto, G. J.

    2004-12-01

    Despite the importance of water to arc magma genesis, fractionation and eruption, few quantitative constraints exist on the water content of Arenal magmas. Early estimates, by electron microprobe sum deficit, suggested up to 4 wt% H2O in olivine-hosted basaltic andesite melt inclusions (MI) from pre-historic ET-6 tephra (Melson, 1982), and up to 7 wt% H2O in plagioclase and orthopyroxene-hosted dacitic MI from 1968 lapilli (Anderson, 1979). These high water contents are consistent with abundant hornblende phenocrysts in Arenal volcanics, but inconsistent with geochemical tracers such as 10Be and Ba/La that suggest a low flux of recycled material (and presumably water) from the subduction zone. In order to test these ideas, and provide the first direct measurements of water in mafic Arenal magmas, we have studied olivine-hosted MI from the prehistoric (900 yBP; Soto et al., 1998) ET3 tephra layer. MI range from andesitic (> 58% SiO2) to basaltic compositions ( 4 wt%) found here for Arenal basaltic MI support the semi-quantitative data from earlier studies, but are somewhat unexpected given predictions from slab tracers. Arenal water contents (4%) approach those of the 1995 eruption of Cerro Negro in Nicaragua (4-5 wt% in basaltic MI; Roggensack et al., 1997), despite the fact that the latter has Ba/La of > 100, while Arenal has Ba/La Boletin de Volcanologia; Roggensack et al. (1997) Science; Soto et al. (1998) OSIVAM; Williams-Jones et al. (2001) Journal of Volc. and Geoth. Res.

  14. A Fungal-Prokaryotic Consortium at the Basalt-Zeolite Interface in Subseafloor Igneous Crust.

    Science.gov (United States)

    Ivarsson, Magnus; Bengtson, Stefan; Skogby, Henrik; Lazor, Peter; Broman, Curt; Belivanova, Veneta; Marone, Federica

    2015-01-01

    We have after half a century of coordinated scientific drilling gained insight into Earth´s largest microbial habitat, the subseafloor igneous crust, but still lack substantial understanding regarding its abundance, diversity and ecology. Here we describe a fossilized microbial consortium of prokaryotes and fungi at the basalt-zeolite interface of fractured subseafloor basalts from a depth of 240 m below seafloor (mbsf). The microbial consortium and its relationship with the surrounding physical environment are revealed by synchrotron-based X-ray tomographic microscopy (SRXTM), environmental scanning electron microscopy (ESEM), and Raman spectroscopy. The base of the consortium is represented by microstromatolites-remains of bacterial communities that oxidized reduced iron directly from the basalt. The microstromatolites and the surrounding basalt were overlaid by fungal cells and hyphae. The consortium was overgrown by hydrothermally formed zeolites but remained alive and active during this event. After its formation, fungal hyphae bored in the zeolite, producing millimetre-long tunnels through the mineral substrate. The dissolution could either serve to extract metals like Ca, Na and K essential for fungal growth and metabolism, or be a response to environmental stress owing to the mineral overgrowth. Our results show how microbial life may be maintained in a nutrient-poor and extreme environment by close ecological interplay and reveal an effective strategy for nutrient extraction from minerals. The prokaryotic portion of the consortium served as a carbon source for the eukaryotic portion. Such an approach may be a prerequisite for prokaryotic-eukaryotic colonisation of, and persistence in, subseafloor igneous crust.

  15. Lunar Meteorites: What They Tell us About the Spatial and Temporal Distribution of Mare Basalts

    Science.gov (United States)

    Basilevsky, A. T.; Neukum, G.; Nyquist, L.

    2010-01-01

    Here we analyze the chronology and statistical distribution of lunar meteorites with emphasis on the spatial and temporal distribution of lunar mare basalts. The data are mostly from the Lunar Meteorite Compendium (http://www-curator.jsc.nasa.gov/ antmet/ lmc/contents.cfm cited hereafter as Compendium) compiled by Kevin Righter, NASA Johnson Space Center, and from the associated literature. The Compendium was last modified on May 12, 2008.

  16. Determination of properties of Proterozoic continental flood basalts of western part from North Qilian Mountains

    Institute of Scientific and Technical Information of China (English)

    夏林圻; 夏祖春; 赵江天; 徐学义; 杨合群; 赵东宏

    1999-01-01

    Proterozoic volcanic rocks of the western part from the North Qilian Mountains are the products of continental rift volcanism, belonging to continental flood basalts, the petrogeochemistry of which apears to suggest that they are derived from sub-lithospheric mantle plume sources, but that they also show evidence of continental lithosphere components involvement. Their formation is the consequences of plume-lithosphere interactions and is precursive to the opening of the North Qilian Early-Paleozoic ocean basin.

  17. Pore water chemistry reveals gradients in mineral transformation across a model basaltic hillslope

    Science.gov (United States)

    Pohlmann, Michael; Dontsova, Katerina; Root, Robert; Ruiz, Joaquin; Troch, Peter; Chorover, Jon

    2016-06-01

    The extent of weathering incongruency during soil formation from rock controls local carbon and nutrient cycling in ecosystems, as well as the evolution of hydrologic flow paths. Prior studies of basalt weathering, including those that have quantified the dynamics of well-mixed, bench-scale laboratory reactors or characterized the structure and integrated response of field systems, indicate a strong influence of system scale on weathering rate and trajectory. For example, integrated catchment response tends to produce lower weathering rates than do well mixed reactors, but the mechanisms underlying these disparities remain unclear. Here we present pore water geochemistry and physical sensor data gathered during two controlled rainfall-runoff events on a large-scale convergent model hillslope mantled with 1 m uniform depth of granular basaltic porous media. The dense sampler and sensor array (1488 samplers and sensors embedded in 330 m3 of basalt) showed that rainfall-induced dissolution of basaltic glass produced supersaturation of pore waters with respect to multiple secondary solids including allophane, gibbsite, ferrihydrite, birnessite and calcite. The spatial distribution of saturation state was heterogeneous, suggesting an accumulation of solutes leading to precipitation of secondary solids along hydrologic flow paths. Rapid dissolution of primary silicates was widespread throughout the entire hillslope, irrespective of up-gradient flowpath length. However, coherent spatial variations in solution chemistry and saturation indices were observed in depth profiles and between distinct topographic regions of the hillslope. Colloids (110-2000 nm) enriched in iron (Fe), aluminum (Al), and phosphorus (P) were mobile in soil pore waters.

  18. Basalt Waste Isolation Project. Quarterly report, January 1-March 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Deju, R.A.

    1980-04-01

    This report addresses the technical progress for the Basalt Waste Isolation Project for the second quarter of fiscal year 1980. Seismic design values were developed for preliminary repository design purposes; 0.25 g horizontal and 0.125 g vertical maximum accelerations for surface, zero-period conditions. Preliminary seismic data indicate broad, smooth areas exist in the bedrock surface in the western portion of the Cold Creek syncline and a gently undulating bedrock surface in the eastern portion. Test results indicate hydraulic property values fall within the range previously reported for sedimentary and interflow zones in basalt formations at the Hanford Site. Preliminary results of available hydrochemical data obtained from several borehole sites indicate that little, if any, vertical mixing of groundwaters is taking place across this stratigraphic boundary. Multiple barrier studies indicate that the primary candidate canister/overpack alloys are TiCode-12, Inconel 625, Incoloy 825, and Zircaloy 2. Low-carbon steel and cast iron are among the list of secondary candidate canister alloys. Laboratory tests of borehole plug designs have shown that it is feasible to design a composite plug system that will satisfactorily seal a nuclear waste repository in Columbia River basalt. The National Lead Industries, Inc., NLI-1/2 Universal Spent Fuel Shipping Cask was selected for use in Phase II operations. Creep test results of samples of Umtanum basalt from borehole DC-6 were plotted and show the day-to-day variation in deformation versus time. The concept selection phase of repository conceptual design was completed in March 1980. A test plan for the Exploratory Shaft Test Facility was developed and is scheduled for submittal to the US Department of Energy in May 1980.

  19. Pb-, Sr- and Nd-Isotopic systematics and chemical characteristics of cenozoic basalts, Eastern China

    Science.gov (United States)

    Peng, Z.C.; Zartman, R.E.; Futa, K.; Chen, D.G.

    1986-01-01

    Forty-eight Paleogene, Neogene and Quaternary basaltic rocks from northeastern and east-central China have been analyzed for major-element composition, selected trace-element contents, and Pb, Sr and Nd isotopic systematics. The study area lies entirely within the marginal Pacific tectonic domain. Proceeding east to west from the continental margin to the interior, the basalts reveal an isotopic transition in mantle source material and/or degree of crustal interaction. In the east, many of the rocks are found to merge both chemically and isotopically with those previously reported from the Japanese and Taiwan island-arc terrains. In the west, clear evidence exists for component(s) of Late Archean continental lithosphere to be present in some samples. A major crustal structure, the Tan-Lu fault, marks the approximate boundary between continental margin and interior isotopic behaviors. Although the isotopic signature of the western basalts has characteristics of lower-crustal contamination, a subcrustal lithosphere, i.e. an attached mantle keel, is probably more likely to be the major contributor of their continental "flavor". The transition from continental margin to interior is very pronounced for Pb isotopes, although Sr and Nd isotopes also combine to yield correlated patterns that deviate strikingly from the mid-ocean ridge basalt (MORB) and oceanic-island trends. The most distinctive chemical attribute of this continental lithosphere component is its diminished U Pb as reflected in the Pb isotopic composition when compared to sources of MORB, oceanic-island and island-arc volcanic rocks. Somewhat diminished Sm Nd and elevated Rb Sr, especially in comparison to the depleted asthenospheric mantle, are also apparent from the Nd- and Sr-isotopic ratios. ?? 1986.

  20. GEOCHEMISTRY OF BASALT AND XENOLITHS AND ITS DEEP PROCESS IN DAOXIAN COUNTY,HUNAN PROVINCE

    Institute of Scientific and Technical Information of China (English)

    KONG Hua; XI Xiao-shuang; JIN Zhen-min; HUANG De-zhi

    2001-01-01

    @@ Deep xenolith are important samples for us to know composition and nature of the deep crust.There are many new volcanos which can all kinds of xenoliths such as a lower crustal graulite,and upper mantle-derived peridolite and lherzolite.In eastern China,there occured many deep xenoliths in Mesozoic-Cenzoic alkaline basalt.Besides these,some small volcanos eruptions were founded in southern Hunan province,which age is about 132-151 Ma.