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Sample records for basalt

  1. Moessbauer Studies of Volhynian Basalts

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  2. Mantle dynamics and basalt petrogenesis

    Science.gov (United States)

    Ringwood, A. E.

    1985-03-01

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

  3. Giant Plagioclase Basalts, eruption rate versus time

    Indian Academy of Sciences (India)

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

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

  4. Flood basalts and extinction events

    Science.gov (United States)

    Stothers, Richard B.

    1993-01-01

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

  5. Thermoluminescence dating of Hawaiian basalt

    Science.gov (United States)

    May, Rodd James

    1979-01-01

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

  6. 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

  7. Subseafloor basalts as fungal habitats

    Directory of Open Access Journals (Sweden)

    M. Ivarsson

    2012-09-01

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

  8. Geochemistry of sulfur isotopes in basaltic rocks

    International Nuclear Information System (INIS)

    Hubberten, H.W.; Puchelt, H.

    1980-01-01

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

  9. Giant Plagioclase Basalts, eruption rate versus time

    Indian Academy of Sciences (India)

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

  10. 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

  11. 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.

  12. Hydrothermal evolution of repository groundwaters in basalt

    International Nuclear Information System (INIS)

    Apps, J.A.

    1984-01-01

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

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

    Science.gov (United States)

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

    2006-12-01

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

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

    International Nuclear Information System (INIS)

    Fujimaki, H.; Tatsumoto, M.

    1984-01-01

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

  15. 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.

  16. Study of crystallization of a basalt glass

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1987-03-01

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

  18. Experimental alterations on ceramic interest basalts

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  19. Vapor deposition in basaltic stalactites, Kilauea, Hawaii

    Science.gov (United States)

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

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

  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...... by varying the temperature of heat treatment. The predominant crystalline phase in the glass was identified as augite. It was found that the hardness of the glass phase decreased slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreased....

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

    Science.gov (United States)

    Huixin, Hei; Shangguo, Su; Yu, Wang

    2014-05-01

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

  2. Plasma sprayed basalt/chromium oxide coatings

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

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

  3. Petrography of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

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

  4. Hydrogen isotope systematics of submarine basalts

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-10-01

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

  5. Basalt: structural insight as a construction material

    Indian Academy of Sciences (India)

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

  6. Thermal models for basaltic volcanism on Io

    Science.gov (United States)

    Keszthelyil, L.; McEwen, A.

    1997-01-01

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

  7. Pressure grouting of fractured basalt flows

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.

    2001-07-02

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

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

    Directory of Open Access Journals (Sweden)

    URKHANOVA Larisa Alekseevna

    2014-08-01

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

  10. Effects of Basalt Fibres on Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    El-Gelani A. M.

    2018-01-01

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

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

    African Journals Online (AJOL)

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

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

    Indian Academy of Sciences (India)

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

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

  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. Biogenic Mn-Oxides in Subseafloor Basalts.

    Science.gov (United States)

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

    2015-01-01

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

  15. Structural relaxation in annealed hyperquenched basaltic glasses

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  16. Hydrologic modeling of the Columbia Plateau basalts

    International Nuclear Information System (INIS)

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

    1982-09-01

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

  17. 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

  18. 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.

  19. Degassing of reduced carbon from planetary basalts.

    Science.gov (United States)

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

    2013-05-14

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

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

    International Nuclear Information System (INIS)

    Turner, D.A.

    1981-01-01

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

  1. Hydrogeology of the basalts in the Uruguayan NW

    International Nuclear Information System (INIS)

    Hausman, A.; Fernandez, A.

    1967-01-01

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

  2. 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...

  3. 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.

  4. Mineral chemistry of Pangidi basalt flows from Andhra Pradesh

    Indian Academy of Sciences (India)

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

  5. Basalt Weathering and the Volatile Budget of Early Mars

    Science.gov (United States)

    Baker, L. L.

    2017-10-01

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

  6. Influence of basalt/groundwater interactions on radionuclide migration

    International Nuclear Information System (INIS)

    Vandegrift, G.F.

    1984-01-01

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

  7. 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...

  8. 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

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

    International Nuclear Information System (INIS)

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

    1980-03-01

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

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

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.

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

  11. Rheological evolution of planetary basalts during cooling and crystallization

    Science.gov (United States)

    Sehlke, Alexander

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

  12. Petrology of Gakkel Ridge Basalts: Preliminary Results

    Science.gov (United States)

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

    2001-12-01

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

  13. Vesiculation of basaltic magma during eruption

    Science.gov (United States)

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

    1993-01-01

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

  14. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  16. Sardinian basalt. An ancient georesource still en vougue

    Science.gov (United States)

    Careddu, Nicola; Grillo, Silvana Maria

    2017-04-01

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

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

    Science.gov (United States)

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

    2018-02-01

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

  18. Basaltic volcanic episodes of the Yucca Mountain region

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M.

    1990-03-01

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

  19. 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

  20. Hafnium isotope variations in oceanic basalts

    Science.gov (United States)

    Patchett, P. J.; Tatsumoto, M.

    1980-01-01

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

  1. Magnesium-rich Basalts on Mercury

    Science.gov (United States)

    Martel, L. M. V.

    2013-05-01

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

  2. Basalt FRP Spike Repairing of Wood Beams

    Directory of Open Access Journals (Sweden)

    Luca Righetti

    2015-08-01

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

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

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

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

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

    Science.gov (United States)

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

    1977-01-01

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

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

    Science.gov (United States)

    Tselebrovskiy, Alexey; Maksimochkin, Valery

    2017-04-01

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

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

    African Journals Online (AJOL)

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

  7. 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

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

    OpenAIRE

    Hidayet BAYRAKTAR; Ayhan SAMANDAR; Suat SARIDEMİR

    2017-01-01

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

  9. 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.

  10. Plate tectonics and continental basaltic geochemistry throughout Earth history

    Science.gov (United States)

    Keller, Brenhin; Schoene, Blair

    2018-01-01

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

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

    Science.gov (United States)

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

    2017-02-21

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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  13. Vapor segregation and loss in basaltic melts

    Science.gov (United States)

    Edmonds, M.; Gerlach, T.M.

    2007-01-01

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

  14. 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.

  15. 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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

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

    DEFF Research Database (Denmark)

    Søager, Nina

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

  19. Flood basalt volcanism on the Moon and Mars

    International Nuclear Information System (INIS)

    Benes, K.

    1979-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  1. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    ,

    1976-11-01

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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

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

  5. Mineral chemistry of Pangidi basalt flows from Andhra Pradesh

    Indian Academy of Sciences (India)

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

  6. Automated identification of basalt spectra in Clementine lunar data

    Science.gov (United States)

    Antonenko, I.; Osinski, G. R.

    2011-06-01

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

  7. 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.

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

    Indian Academy of Sciences (India)

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

  9. Alteration of basaltic glasses from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

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

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

    Indian Academy of Sciences (India)

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

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

    African Journals Online (AJOL)

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

  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

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

  13. 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)

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

    International Nuclear Information System (INIS)

    1979-11-01

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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

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

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

    Science.gov (United States)

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

    2017-10-01

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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

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

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

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Baker, Joel A.

    2012-01-01

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

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

    Indian Academy of Sciences (India)

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

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

    International Nuclear Information System (INIS)

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

    1991-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Nasir Amel

    2016-12-01

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

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

    Science.gov (United States)

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

    2013-03-01

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

  5. 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

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

    Science.gov (United States)

    Talebi Mazraehshahi, H.; Zamani, H.

    2010-06-01

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

  7. 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.

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

    International Nuclear Information System (INIS)

    Asfahani, Jamal

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Rickert, P.G.

    1980-01-01

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

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

    Science.gov (United States)

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

    2015-07-14

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

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

    Science.gov (United States)

    Herzberg, C. T.

    1979-01-01

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

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

    Science.gov (United States)

    Puffer, J. H.

    2007-12-01

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

  13. Basalt-trachybasalt samples in Gale Crater, Mars

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  14. Genetic aspects of basalts from the Carlsberg Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

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

  15. 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

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  18. 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.

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

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

    Science.gov (United States)

    Weisler, M I; Woodhead, J D

    1995-01-01

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

  1. 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.

  2. 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.

  3. H2O solubility in basalt at upper mantle conditions

    Science.gov (United States)

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

    2017-10-01

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

  4. 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

  5. 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].

  6. 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...

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

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1983-01-01

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

  8. 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.

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

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

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

  10. 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.

  11. Nuclear waste repository in basalt: preconceptual design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

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

  12. Nuclear waste repository in basalt: preconceptual design guidelines

    International Nuclear Information System (INIS)

    1979-06-01

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

  13. 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.

  14. Friction Joint Between Basalt-Reinforced Composite and Aluminum

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  15. Environmental issue identification for the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

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

    1980-04-01

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

  16. 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.

  17. Sentinel Gap basalt reacted in a temperature gradient

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  18. Hydrologic bibliography of the Columbia River basalts in Washington

    International Nuclear Information System (INIS)

    Tanaka, H.H.; Wildrick, L.

    1978-07-01

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

  19. Geochemical characterization of oceanic basalts using artificial neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.

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

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    and appear to be contaminated at a shallow level. The 187Os/188Os ratios in the remaining lavas with >30 ppt Os (n = 17) range between 0.12117 and 0.13324. These values are surprisingly low for oceanic island basalts and include some samples that are less than putative present-day primitive upper mantle (PUM....... Material from the Iceland mantle plume likely migrates at depth until it reaches the tensional setting of the Jan Mayen Fracture Zone, where it undergoes low-degree partial melting. At a first-order, isotopic co-variations can be interpreted as broadly binary mixing curves between two primary end...

  1. 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.

  2. Sub-basalt imaging problems and the application of Artificial Neural Networks

    Science.gov (United States)

    Fitzgerald, Elaine M.; Bean, Christopher J.

    2001-12-01

    In many areas of the world, the presence of shallow high velocity, highly heterogeneous layers complicate seismic imaging of deeper reflectors. Of particular economic interest are areas where potentially hydrocarbon-bearing strata are obscured by layers of basalt. Basalt layers are highly reflective and heterogeneous. Using reflection seismic, top basalt is typified by a high-amplitude, coherent reflector with poor resolution of reflectors below the basalt, and even bottom basalt. Here, we present a new approach to the imaging problem using the pattern recognition abilities of a back-propagation Artificial Neural Network (ANN). ANNs are computational systems that attempt to mimic natural biological neural networks. They have the ability to recognize patterns and develop their own generalizations about a given data set. Back-propagation neural networks are trained on data sets for which the solution is known and tested on the data that are not previously presented to the ANN in order to validate the network result. We show that Artificial Neural Networks, due to their pattern recognition capabilities, can invert the medium statistics based on the seismic character. We produce statistically defined models involving a basalt analogous layer, and calculate full wavefield finite difference synthetic seismograms. We vary basalt layer thickness and source frequency to generate a synthetic model that produces seismic that is similar to real sub-basalt seismic, i.e. high amplitude top basalt reflector and the absence of base basalt and sub-basalt events. Using synthetic shot gathers, generated in a synthetic representation of the sub-basalt case, we can invert the velocity medium standard deviation by using an ANN. By inverting the velocity medium standard deviation, we successfully identified the transition from basalt to sub-basalt on the synthetic shot gathers. We also show that ANNs are capable of identifying the basalt to sub-basalt transition in the presence of

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

    Science.gov (United States)

    Xiao, Li-guang; Li, Gen-zhuang

    2018-03-01

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

  4. 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.

  5. 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.

  6. Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

    International Nuclear Information System (INIS)

    Bennecke, W.M.

    1996-10-01

    A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well

  7. Characterization and recognition of intraflow structures, Grande Ronde Basalt

    International Nuclear Information System (INIS)

    Long, P.E.

    1978-09-01

    This investigation was carried out as part of a feasibility study for long-term storage of nuclear waste at depth in the Pasco Basin. Three general types of intraflow structures were found at Sentinel Gap: flows with stubby, irregular columns that lack a well-developed entablature; flows consisting of multiple tiers of largely entablature-type columns; and flows with a well-developed colonnade and entablature showing a sharp break between the two. Certain features occur locally in all three types of intraflow structures: variations in fracture morphology, primary platey fracture zones, pillow-palagonite zones, and tectonically induced zones of closely spaced fractures. Fractures in each of the three types of flows were logged both at the surface and in core from Core Hole DH-5, and petrographic textures of basalt sampled from surface exposures were examined. The textures of the basalt correlate with the intraflow structures and provide a technique for identifying flows as to their general type of intraflow structure, locating internal contacts between intraflow structures and possibly estimating fracture density within flows. Fracture logging, on the other hand, does not accurately delimit intraflow structures

  8. Fungal colonies in open fractures of subseafloor basalt

    Science.gov (United States)

    Ivarsson, Magnus; Bengtson, Stefan; Skogby, Henrik; Belivanova, Veneta; Marone, Federica

    2013-08-01

    The deep subseafloor crust is one of the few great frontiers of unknown biology on Earth and, still today, the notion of the deep biosphere is commonly based on the fossil record. Interpretation of palaeobiological information is thus central in the exploration of this hidden biosphere and, for each new discovery, criteria used to establish biogenicity are challenged and need careful consideration. In this paper networks of fossilized filamentous structures are for the first time described in open fractures of subseafloor basalts collected at the Emperor Seamounts, Pacific Ocean. These structures have been investigated with optical microscopy, environmental scanning electron microscope, energy dispersive spectrometer, X-ray powder diffraction as well as synchrotron-radiation X-ray tomographic microscopy, and interpreted as fossilized fungal mycelia. Morphological features such as hyphae, yeast-like growth and sclerotia were observed. The fossilized fungi are mineralized by montmorillonite, a process that probably began while the fungi were alive. It seems plausible that the fungi produced mucilaginous polysaccharides and/or extracellular polymeric substances that attracted minerals or clay particles, resulting in complete fossilization by montmorillonite. The findings are in agreement with previous observations of fossilized fungi in subseafloor basalts and establish fungi as regular inhabitants of such settings. They further show that fossilized microorganisms are not restricted to pore spaces filled by secondary mineralizations but can be found in open pore spaces as well. This challenges standard protocols for establishing biogenicity and calls for extra care in data interpretation.

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

    Science.gov (United States)

    Schipper, C. Ian; Moussallam, Yves

    2017-10-01

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

  10. The Disruption of Tephra Fall Deposits by Basaltic Lava Flows

    Science.gov (United States)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2010-12-01

    Complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents of the Roza Member in the Columbia River Basalt Province, (CRBP), USA, illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter tephra fall deposits. Thin pahoehoe lobes and sheet lobes occur intercalated with tephra deposits and provide evidence for synchronous effusive and explosive activity. Tephra that accumulated on the tops of inflating pahoehoe flows became disrupted by tumuli, which dissected the overlying sheet into a series of mounds. During inflation of subjacent tumuli tephra percolated down into the clefts and rubble at the top of the lava, and in some cases came into contact with lava hot enough to thermally alter it. Lava breakouts from the tumuli intruded up through the overlying tephra deposit and fed pahoehoe flows that spread across the surface of the aggrading tephra fall deposit. Non-welded scoria fall deposits were compacted and welded to a depth of ~50 cm underneath thick sheet lobes. These processes, deduced from the field relationships, have resulted in considerable stratigraphic complexity in proximal regions. We also demonstrate that, when the advance of lava and the fallout of tephra are synchronous, the contacts of some tephra sheets can be diachronous across their extent. The net effect is to reduce the usefulness of pyroclastic deposits in reconstructing eruption dynamics.

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

    Science.gov (United States)

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

    2017-04-01

    Geothermobarometry of solid fragments in kimberlite and alkali basalts, generally called "xenoliths", provides information on thermal and chemical structure of lithospheric and asthenospheric mantle, based on which various chemical, thermal, and rheological models of lithosphere have been constructed (e.g., Griffin et al., 2003; McKenzie et al., 2005; Ave Lallemant et al., 1980). Geothermobarometry for spinel-bearing peridotite fragments, which are frequently sampled from Phanerozoic provinces in various tectonic environments (Nixon and Davies, 1987), has essential difficulties, and it is usually believed that appropriated barometers do not exist for them (O'Reilly et al., 1997; Medaris et al., 1999). Ozawa et al. (2016; EGU) proposed a method of geothermobarometry for spinel lherzolite fragments. They applied the method to mantle fragments in alkali basalts from Bou Ibalhatene maars in the Middle Atlas in Morocco (Raffone et al. 2009; El Azzouzi et al., 2010; Witting et al., 2010; El Messbahi et al., 2015). Ozawa et al. (2016) obtained 0.5GPa pressure difference (1.5-2.0GPa) for 100°C variation in temperatures (950-1050°C). However, it is imperative to verify the results on the basis of completely independent data. There are three types of independent information: (1) time scale of solid fragment extraction, which may be provided by kinetics of reactions induced by heating and/or decompression during their entrapment in the host magma and transportation to the Earth's surface (Smith, 1999), (2) depth of the host basalt formation, which may be provided by the petrological and geochemical studies of the host basalts, and (3) lithosphere-asthenosphere boundary depths, which may be estimated by geophysical observations. Among which, (3) is shown to be consistent with the result in Ozawa et al. (2016). We here present that the estimated thermal structure just before the fragment extraction is fully supported by the information of (1) and (2). Spera (1984) reviewed

  12. Intracanyon basalt lavas of the Debed River (northern Armenia), part of a Pliocene-Pleistocene continental flood basalt province in the South Caucasus

    Science.gov (United States)

    Sheth, Hetu; Meliksetian, Khachatur; Gevorgyan, Hripsime; Israyelyan, Arsen; Navasardyan, Gevorg

    2015-03-01

    Late Pliocene to Early Pleistocene (~ 3.25-2.05 Ma), 200-400 m thick basalt lavas outcrop in the South Caucasus region, including the Kars-Erzurum Plateau (northeastern Turkey), the Javakheti Plateau (Georgia-Armenia), and the Lori Plateau (northern Armenia). These fissure-fed, rapidly erupted fluid lavas filled pre-existing river valleys over many tens of kilometres. The basalts exposed in the Debed River canyon, northern Armenia, are ~ 200 m thick and of three morphological types: (1) basal pillow basalts and hyaloclastites, overlain by (2) columnar-jointed pahoehoe sheet flows, in turn overlain by (3) slabby pahoehoe and rubbly pahoehoe flows. The lower and middle lavas show evidence for damming of river drainage, like many lavas of the Columbia River flood basalt province, Scotland, Ireland, and Iceland. There is also evidence for syn-volcanic faulting of the early lavas. Related basalts also outcrop in the Gegham Uplands and the Hrazdan River basin in Armenia. This 3.25-2.05 Ma South Caucasus basalt province, covering parts of Turkey, Georgia and Armenia, has an estimated areal extent of ~ 15,000 km2 and volume of ~ 2250 km3. Because its main geological features are remarkably like those of many continental flood basalt (CFB) provinces, we consider it a true, albeit small, CFB province. It is the smallest and youngest CFB in the world. An analogue closely similar in major features is the Late Miocene Altos de Jalisco CFB province in the western Trans-Mexican Volcanic Belt. Both provinces formed during lithospheric pull-apart and transtensional faulting. Their broader significance is in showing flood basalt size distribution to be a continuum without natural breaks, with implications for geodynamic models.

  13. Post-Columbia River Basalt Group stratigraphy and map compilation of the Columbia Plateau, Oregon

    International Nuclear Information System (INIS)

    Farooqui, S.M.; Bunker, R.C.; Thoms, R.E.; Clayton, D.C.; Bela, J.L.

    1981-01-01

    This report presents the results of reconnaissance mapping of sedimentary deposits and volcanic rocks overlying the Columbia River Basalt. The project area covers parts of the Dalles, Pendleton, Grangeville, Baker, Canyon City, and Bend. The mapping was done to provide stratigraphic data on the sedimentary deposits and volcanic rocks overlying the Columbia River Basalt Group. 160 refs., 16 figs., 1 tab

  14. 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...

  15. From mantle roots to surface eruptions: Cenozoic and Mesozoic continental basaltic magmatism

    Czech Academy of Sciences Publication Activity Database

    Kämpf, H.; Németh, K.; Puziewicz, J.; Mrlina, Jan; Geissler, W.H.

    2015-01-01

    Roč. 104, č. 8 (2015), s. 1909-1912 ISSN 1437-3254 Institutional support: RVO:67985530 Keywords : continental basaltic volcanism * BASALT 2013 conference * Cenozoic * Mesozoic Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.133, year: 2015

  16. 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.

  17. Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.; Hazra, S.

    ferrobasaltic composition. The basalts have high incompatible elements (Zr 63-228 ppm; Nb approx. 1-5 ppm; Ba approx. 15-78 ppm; La approx. 3-16 ppm), a similar U/Pb (0.02-0.4) ratio as the normal mid-oceanic basalt (0.16 plus or minus 0.07) but the Ba/Nb (12...

  18. Experimental investigation of the reaction between corundum xenocrysts and alkaline basaltic host magma: Constraints on magma residence times of basalt-hosted sapphires

    Science.gov (United States)

    Baldwin, L. C.; Ballhaus, C.

    2018-03-01

    Megacrystic sapphires (Fe-Ti-rich corundum) of up to 5 cm in size are well known from alkaline mafic rocks from intra-continental rift-related magmatic fields. There is no doubt that these sapphires represent xenocrysts that were trapped from their original lithology by ascending basaltic magmas carrying them to the Earth's surface. Most studies about basalt-hosted sapphires address the question about the origin of the sapphires, but there is hardly any information available about the time the sapphires resided inside the carrier melt. Sapphires are in reaction relationship with basalt and produce spinel coronas at the sapphire-basalt interface, spatially separating the mutually incompatible phases from one another. Assuming isothermal and isobaric conditions of spinel rim formation, the rim-thickness should be a function of the reaction time with the basaltic melt. In this paper, we report time-series experiments aimed at investigating the kinetics of spinel rim formation due to igneous corrosion of corundum. Therefore, we reacted corundum fragments with alkaline basalt powder at 1250 °C and 1GPa, using a Piston Cylinder Apparatus. The width of the spinel rim was used to estimate a residence time. Extrapolating the experimentally derived reaction rates to the thickness of natural spinel rims as described from the Siebengebirge Volcanic Field, Germany, and from Changle, China, we estimated residence times in the order of a few weeks to months.

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

    Science.gov (United States)

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

    2015-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-09-01

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

  1. 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.

  2. Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre

    Science.gov (United States)

    Shafiq, Nasir; Fadhilnuruddin, Muhd; Elshekh, Ali Elheber Ahmed; Fathi, Ahmed

    2015-07-01

    Ultrasonic pulse velocity (UPV), is considered as the most important test for non-destructive techniques that are used to evaluate the mechanical characteristics of high strength concrete (HSC). The relationship between the compressive strength of HSC containing chopped basalt fibre stands (CBSF) and UPV was investigated. The concrete specimens were prepared using a different ratio of CBSF as internal strengthening materials. The compressive strength measurements were conducted at the sample ages of 3, 7, 28, 56 and 90 days; whilst, the ultrasonic pulse velocity was measured at 28 days. The result of HSC's compressive strength with the chopped basalt fibre did not show any improvement; instead, it was decreased. The UPV of the chopped basalt fibre reinforced concrete has been found to be less than that of the control mix for each addition ratio of the basalt fibre. A relationship plot is gained between the cube compressive strength for HSC and UPV with various amounts of chopped basalt fibres.

  3. Corrosion of uncoated and oxide-coated basalt fibre in different alkaline media

    International Nuclear Information System (INIS)

    Rybin, V.A.; Utkin, A.V.; Baklanova, N.I.

    2016-01-01

    Highlights: • Alkaline corrosion of uncoated and coated basalt fibre in alkali media was studied. • Degradation of the fibre involves the dissolution of alumosilicate network in alkali media. • Insoluble shell from iron and calcium hydroxides and carbonates is formed. • Zirconia and titania coatings slow down the corrosion of basalt fibre significantly. - Abstract: The corrosion behaviour of the zirconium dioxide and titanium dioxide coated basalt fibre in sodium and calcium hydroxide solutions was studied. The morphology, elemental, phase composition of fibre before and after exposure to alkaline media was examined by different analytical techniques. It was shown that the oxide coatings slow down corrosion, and zirconium dioxide slows down corrosion of basalt fibre to a higher extent than titanium dioxide. The morphology and composition of solid corrosion products depend on a type of alkaline medium. The schemes of corrosion for the uncoated and coated basalt fibres in alkaline media were proposed.

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

    International Nuclear Information System (INIS)

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

    1978-09-01

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

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

    Science.gov (United States)

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

    1966-01-01

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

  6. 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.

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

    Science.gov (United States)

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

    1977-01-01

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

  8. Fire performance of basalt FRP mesh reinforced HPC thin plates

    DEFF Research Database (Denmark)

    Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup

    2013-01-01

    An experimental program was carried out to investigate the influence of basalt FRP (BFRP) reinforcing mesh on the fire behaviour of thin high performance concrete (HPC) plates applied to sandwich elements. Samples with BFRP mesh were compared to samples with no mesh, samples with steel mesh...... and samples displaying a full sandwich structure. Final results confirmed the bond loss between concrete and BFRP mesh with temperature. The available void where the epoxy burnt away allowed the concrete matrix to release pressure and limit pore stresses, delaying spalling. It also reduced the mechanical...... on a linear increase of the volume of melted epoxy and the outflow of moisture from the concrete matrix. It was concluded that the use of a BFRP mesh to reinforce HPC exposed to fire reduces the mechanical strength despite a beneficial effect related to spalling....

  9. Nuclear waste repository in basalt: a design description

    International Nuclear Information System (INIS)

    Ritchie, J.S.; Schmidt, B.

    1982-01-01

    The conceptual design of a nuclear waste repository in basalt is described. Nuclear waste packages are placed in holes drilled into the floor of tunnels at a depth of 3700 ft. About 100 miles of tunnels are required to receive 35,000 packages. Five shafts bring waste packages, ventilation air, excavated rock, personnel, material, and services to and from the subsurface. The most important surface facility is the waste handling building, located over the waste handling shaft, where waste is received and packaged for storage. Two independent ventilation systems are provided to avoid potential contamination of spaces that do not contain nuclear waste. Because of the high temperatures at depth, an elaborate air chilling system is provided. Because the waste packages deliver a considerable amount of heat energy to the rock mass, particular attention is paid to heat transfer and thermal stress studies. 3 references, 31 figures, 3 tables

  10. Geomechanical testing development for the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    Cramer, M.L.; Dischler, S.A.; Erb, D.B.; Berlin, G.T.; Wittreich, C.D.; Bauer, R.E.

    1987-04-01

    One component of this project is the development of a geomechanical testing program to support repository design, site characterization, and performance assessment requirements. Geomechanics information includes characteristics of the in situ stress field and the mechanical properties of the rock mass. The nature of the basalts at the proposed repository depth of approximately 970 m imposes some relatively unusual requirements on testing methods typically used to assess the stress state and rock mass deformability. The rock mass is closely jointed, with the spacing estimated from vertical boreholes to be in the range of 5 to 10 cm for both vertical and horizontal joint sets. The ambient temperature at depth is about 50 0 C. The rock mass is considered fully saturated. This presentation summarizes the development effort currently under way to support site characterization testing to be conducted at the candidate repository horizon in the Exploratory Shaft Facility. Development activities include hydraulic fracturing, overcoring, flat jack testing, and borehole dilatometer testing

  11. Tungsten-182 heterogeneity in modern ocean island basalts

    Science.gov (United States)

    Mundl, Andrea; Touboul, Mathieu; Jackson, Matthew G.; Day, James M. D.; Kurz, Mark D.; Lekic, Vedran; Helz, Rosalind T.; Walker, Richard J.

    2017-04-01

    New tungsten isotope data for modern ocean island basalts (OIB) from Hawaii, Samoa, and Iceland reveal variable 182W/184W, ranging from that of the ambient upper mantle to ratios as much as 18 parts per million lower. The tungsten isotopic data negatively correlate with 3He/4He. These data indicate that each OIB system accesses domains within Earth that formed within the first 60 million years of solar system history. Combined isotopic and chemical characteristics projected for these ancient domains indicate that they contain metal and are repositories of noble gases. We suggest that the most likely source candidates are mega-ultralow-velocity zones, which lie beneath Hawaii, Samoa, and Iceland but not beneath hot spots whose OIB yield normal 182W and homogeneously low 3He/4He.

  12. Geoscience parameter data base handbook: granites and basalts

    International Nuclear Information System (INIS)

    1979-12-01

    The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous United States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report

  13. Interim reclamation report: Basalt Waste Isolation Project exploration shaft site

    International Nuclear Information System (INIS)

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

    1990-02-01

    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. Extensive studies of the geotechnical aspects of the site were undertaken, including preparations for drilling a large diameter Exploratory Shaft. This report describes the development of the reclamation program for the Exploratory Shaft Facility, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 43 refs., 19 figs., 9 tabs

  14. 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.

  15. 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.

  16. Repository site definition in basalt: Pasco Basin, Washington

    International Nuclear Information System (INIS)

    Guzowski, R.V.; Nimick, F.B.; Muller, A.B.

    1982-03-01

    Discussion of the regional setting, geology, hydrology, and geochemistry of the Pasco Basin are included in this report. Pasco basin is a structural and topographic basin of approximately 2000 mi 2 (5180 km 2 ) located within the Yakima Fold Belt Subprovince of the Columbia Plateau. The stratigraphic sequence within the basin consists of an undetermined thickness of lower Miocene and younger flood basalts with interbedded and overlying sedimentary units. This sequence rests upon a basement of probably diverse rock types that may range in age from precambrian through early Tertiary. Although a large amount of information is available on the hydrology of the unconfined aquifer system, ground-water flow within the basin is, in general, poorly understood. Recharge areas for the Mabton interbed and the Saddle Mountains Formation are the highlands surrounding the basin with the flow for these units toward Gable Butte - Gable Mountain and Lake Wallula. Gable Butte - Gable Mountain probably is a ground-water sink, although the vertical flow direction in this zone is uncertain. The amount of upward vertical leakage from the Saddle Mountains Formation into the overlying sediments or to the Columbia River is unknown. Units underlying the Mabton interbed may have a flow scheme similar to those higher units or a flow scheme dominated by interbasin flow. Upward vertical leakage either throughout the basin, dominantly to the Columbia River, or dominantly to Lake Wallula has been proposed for the discharge of the lower units. None of these proposals is verified. The lateral and vertical distribution of major and minor ions in solution, Eh and pH, and ion exchange between basalt and ground-water are not well defined for the basin. Changes in the redox potential from the level of the subsurface facility to the higher stratigraphic levels along with the numerous other factors influencing K/sub d/, result in a poor understanding of the retardation process

  17. Tracking Hadean processes in modern basalts with 142-Neodymium

    Science.gov (United States)

    Horan, M. F.; Carlson, R. W.; Walker, R. J.; Jackson, M.; Garçon, M.; Norman, M.

    2018-02-01

    The short-lived 146Sm→142 Nd isotope system (t1/2 = 103 Ma) provides constraints on the timing and processes of terrestrial silicate fractionation during the early Hadean. Although some Archean terranes preserve variability in 142Nd/144Nd, no anomalies have been resolved previously in young rocks. This study provides high precision 142Nd/144Nd data on a suite of ocean island basalts from Samoa and Hawaii previously shown to have variable depletions in 182W/184W that are inversely correlated with 3He/4He ratios. Improved analytical techniques and multiple replicate analyses of Nd show a variation in μ142 Nd values between -1.3 and +2.7 in the suite, relative to the JNdi standard. Given the reproducibility of the standard (±2.9 ppm, 2 SD), two Samoan samples exhibit resolved variability in their 142Nd/144Nd ratios outside of their 95% confidence intervals, suggesting minor variability in the Samoan hotspot. One sample from Samoa has a higher μ142 Nd of +2.7, outside the 95% confidence interval (±1.0 ppm) of the average of the JNdi standard. Limited, but resolved, variation in 142Nd/144Nd within the suite suggests the preservation of early Hadean silicate differentiation in the sources of at least some basalts from Samoa. Larger variations of 182W/184W and 3He/4He ratios in the same samples suggest that metal-silicate separation and mantle outgassing left a more persistent imprint on the accessible mantle compared to 142Nd/144Nd ratios which are impacted by early silicate differentiation.

  18. 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.

  19. The mode of emplacement of Neogene flood basalts in eastern Iceland: Facies architecture and structure of simple aphyric basalt groups

    Science.gov (United States)

    Óskarsson, Birgir V.; Riishuus, Morten S.

    2014-12-01

    Simple flows (tabular) in the Neogene flood basalt sections of Iceland are described and their mode of emplacement assessed. The flows belong to three aphyric basalt groups: the Kumlafell group, the Hólmatindur group and the Hjálmadalur group. The groups can be traced over 50 km and originate in the Breiðdalur-Thingmuli volcanic zone. The groups have flow fields that display mixed volcanic facies architecture and can be classified after dominating type morphology. The Kumlafell and the Hólmatindur groups have predominantly simple flows of pāhoehoe and rubbly pāhoehoe morphologies with minor compound or lobate pāhoehoe flows. The Hjálmadalur group has simple flows of rubbly pāhoehoe, but also includes minor compound or lobate flows of rubble and 'a'ā. Simple flows are most common in the distal and medial areas from the vents, while more lobate flows in proximal areas. The simple flows are formed by extensive sheet lobes that are several kilometers long with plane-parallel contacts, some reaching thicknesses of ~ 40 m (aspect ratios structures. Their internal structure consists generally of a simple upper vesicular crust, a dense core and a thin basal vesicular zone. The brecciated flow-top is formed by clinker and crustal rubble, the clinker often welded or agglutinated. The simple flows erupted from seemingly short-lived fissures and have the characteristics of cooling-limited flows. We estimate the effusion rates to be ~ 105 m3/s for the simple flows of the Kumlafell and Hólmatindur groups and ~ 104 m3/s for the Hjálmadalur group. The longest flows advanced 15-20 km from the fissures, with lava streams of fast propagating flows inducing tearing and brecciation of the chilled crust. Compound or lobate areas appear to reflect areas of low effusion rates or the interaction of the lava with topographic barriers or wetlands, resulting in chaotic flowage. Slowing lobes with brecciated flow-tops developed into 'a'ā flows. The groups interdigitated with lava

  20. 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

  1. Probability encoding of hydrologic parameters for basalt. Elicitation of expert opinions from a panel of three basalt waste isolation project staff hydrologists

    International Nuclear Information System (INIS)

    Runchal, A.K.; Merkhofer, M.W.; Olmsted, E.; Davis, J.D.

    1984-11-01

    The present study implemented a probability encoding method to estimate the probability distributions of selected hydrologic variables for the Cohassett basalt flow top and flow interior, and the anisotropy ratio of the interior of the Cohassett basalt flow beneath the Hanford Site. Site-speciic data for these hydrologic parameters are currently inadequate for the purpose of preliminary assessment of candidate repository performance. However, this information is required to complete preliminary performance assessment studies. Rockwell chose a probability encoding method developed by SRI International to generate credible and auditable estimates of the probability distributions of effective porosity and hydraulic conductivity anisotropy. The results indicate significant differences of opinion among the experts. This was especially true of the values of the effective porosity of the Cohassett basalt flow interior for which estimates differ by more than five orders of magnitude. The experts are in greater agreement about the values of effective porosity of the Cohassett basalt flow top; their estimates for this variable are generally within one to two orders of magnitiude of each other. For anisotropy ratio, the expert estimates are generally within two or three orders of magnitude of each other. Based on this study, the Rockwell hydrologists estimate the effective porosity of the Cohassett basalt flow top to be generally higher than do the independent experts. For the effective porosity of the Cohassett basalt flow top, the estimates of the Rockwell hydrologists indicate a smaller uncertainty than do the estimates of the independent experts. On the other hand, for the effective porosity and anisotropy ratio of the Cohassett basalt flow interior, the estimates of the Rockwell hydrologists indicate a larger uncertainty than do the estimates of the independent experts

  2. Application of the iron-enriched basalt waste form for immobilizing commercial transuranic waste

    International Nuclear Information System (INIS)

    Owen, D.E.

    1981-08-01

    The principal sources of commercial transuranic (TRU) waste in the United States are identified. The physical and chemical nature of the wastes from these sources are discussed. The fabrication technique and properties of iron-enriched basalt, a rock-like waste form developed for immobilizing defense TRU wastes, are discussed. The application of iron-enriched basalt to commercial TRU wastes is discussed. Review of commercial TRU wastes from mixed-oxide fuel fabrication, light water reactor fuel reprocessing, and miscellaneous medical, research, and industrial sources, indicates that iron-enriched basalt is suitable for most types of commercial TRU wastes. Noncombustible TRU wastes are dissolved in the high temperature, oxidizing iron-enriched basalt melt. Combustible TRU wastes are immobilized in iron-enriched basalt by incinerating the wastes and adding the TRU-bearing ash to the melt. Casting and controlled cooling of the melt produces a devitrified, rock-like iron-enriched basalt monolith. Recommendations are given for testing the applicability of iron-enriched basalt to commercial TRU wastes

  3. Stratigraphic imaging of sub-basalt sediments using waveform tomography of wide-angle seismic data

    Science.gov (United States)

    Sain, K.; Gao, F.; Pratt, G.; Zelt, C. A.

    2003-12-01

    The oil industry is interested in imaging the fine structures of sedimentary formations masked below basalt flows for commercial exploration of hydrocarbons. Seismic exploration of sediments hidden below high-velocity basalt cover is a difficult problem because near-vertical reflection data are contaminated with multiples, converted waves and scattering noise generated by interbeds, breccia and vesicles within the basalt. The noise becomes less prominent as the source-receiver offset increases, and the signals carrying sub-surface information stand out at the wide-angle range. The tomography of first arrival traveltime data can provide little information about the underlying low-velocity sediments. Traveltime inversion of wide-angle seismic data including both first arrivals and identifiable wide-angle reflected phases has been an important tool in the delineation of the large-scale velocity structure of sub-basalt sediments, although it lacks the small-scale velocity details. Here we apply 2-D full-waveform inversion ("waveform tomography") to wide-angle seismic data with a view to extracting the small-scale stratigraphic features of sedimentary formations. Results from both synthetic data, generated for a realistic earth model, and field dataset from the basalt covered Saurashtra peninsula, India, will be presented. This approach has potential to delineate thin sedimentary layers hidden below thick basalt cover also, and may serve as a powerful tool to image sedimentary basins, where they are covered by high-velocity materials like basalts, salts, carbonates, etc. in various parts of the world.

  4. Basalt models for the Mars penetrator mission: Geology of the Amboy Lava Field, California

    Science.gov (United States)

    Greeley, R.; Bunch, T. E.

    1976-01-01

    Amboy lava field (San Bernardino County, California) is a Holocene basalt flow selected as a test site for potential Mars Penetrators. A discussion is presented of (1) the general relations of basalt flow features and textures to styles of eruptions on earth, (2) the types of basalt flows likely to be encountered on Mars and the rationale for selection of the Amboy lava field as a test site, (3) the general geology of the Amboy lava field, and (4) detailed descriptions of the target sites at Amboy lava field.

  5. Petrogenesis of basalt-trachyte lavas from Olmoti Crater, Tanzania

    Science.gov (United States)

    Mollel, Godwin F.; Swisher, Carl C., III; McHenry, Lindsay J.; Feigenson, Mark D.; Carr, Michael J.

    2009-08-01

    Olmoti Crater is part of the Plio-Pleistocene Ngorongoro Volcanic Highland (NVH) in northern Tanzania to the south of Gregory Rift. The Gregory Rift is part of the eastern branch of the East African Rift System (EARS) that stretches some 4000 km from the Read Sea and Gulf of Aden in the north to the Zambezi River in Mozambique. Here, we (1) characterize the chemistry and mineral compositions of lavas from Olmoti Crater, (2) determine the age and duration of Olmoti volcanic activity through 40Ar/ 39Ar dating of Olmoti Crater wall lavas and (3) determine the genesis of Olmoti lavas and the relationship to other NVH and EARS volcanics and (4) their correlation with volcanics in the Olduvai and Laetoli stratigraphic sequences. Olmoti lavas collected from the lower part of the exposed crater wall section (OLS) range from basalt to trachyandesite whereas the upper part of the section (OUS) is trachytic. Petrography and major and trace element data reflect a very low degree partial melt origin for the Olmoti lavas, presumably of peridotite, followed by extensive fractionation. The 87Sr/ 86Sr data overlap whereas Nd and Pb isotope data are distinct between OLS and OUS samples. Interpretation of the isotope data suggests mixing of enriched mantle (EM I) with high-μ-like reservoirs, consistent with the model of Bell and Blenkinsop [Bell, K., Blenkinsop, J., 1987. Nd and Sr isotopic compositions of East African carbonatites: implications for mantle heterogeneity. Geology 5, 99-102] for East African carbonatite lavas. The isotope ratios are within the range of values defined by Oceanic Island Basalt (OIB) globally and moderate normalized Tb/Yb ratios (2.3-1.6) in these lavas suggest melting in the lithospheric mantle consistent with other studies in the region. 40Ar/ 39Ar incremental-heating analyses of matrix and anorthoclase separates from Olmoti OLS and OUS lavas indicate that volcanic activity was short in duration, lasting ˜200 kyr from 2.01 ± 0.03 Ma to 1.80 ± 0

  6. The Auckland Volcanic Field - a basaltic field showing random behavior?

    Science.gov (United States)

    Le Corvec, N.; Rowland, J. V.; Lindsay, J. M.

    2012-04-01

    Basaltic monogenetic volcanism is a worldwide phenomenon typically producing fields of volcanic centers that increase in number with time. The process of field growth is not constant but punctuated by single eruptions, flare-ups and hiatuses. The development of a volcanic field involves physical processes that occur in the mantle, where batches of basaltic magma originate, and within the intervening lithosphere through which magma is transferred to the surface. The spatial and temporal distribution of volcanic centers within such volcanic fields results from, and thus may provide insights to, these physical processes (e.g., magma production, tectonic controls), thereby aiding in our understanding of a volcanic field's future development. The Auckland Volcanic Field (AVF), which lies in the most populated area of New Zealand, comprises 50 volcanic centers and produced its last eruption ~600 years ago. A recent study has provided a relative chronology of the entire sequence of eruptions, which is here used together with the spatial distribution of volcanic centers to investigate the evolution of the field in time and space. Two methods were used: 1) the Poisson Nearest Neighbor (PNN) analysis which evaluates the spatial distribution of a natural population over the spatial distribution of a statistical random model, the Poisson model; and 2) the Voronoi analysis which evaluates the spatial characteristics of each volcanic center by dividing a region (i.e., the volcanic field) into a set of polygons. The results of the PNN analysis show that the temporal evolution of the spatial distribution of the volcanic centers within the AVF follows the Poisson model, therefore they cannot be used to extrapolate the future evolution of the volcanic field. The preliminary results of the Voronoi analysis show in combination with the geochemical signatures from some volcanic centers a possible zonation within the source region, and/or the magmas may be variably affected on their way

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

    Science.gov (United States)

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

    2015-04-01

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

  8. Submarine basaltic fountain eruptions in a back-arc basin during the opening of the Japan Sea

    Science.gov (United States)

    Hosoi, Jun; Amano, Kazuo

    2017-11-01

    Basaltic rock generated during the middle Miocene opening of the Japan Sea, is widely distributed on the back-arc side of the Japanese archipelago. Few studies have investigated on submarine volcanism related to opening of the Japan Sea. The present study aimed to reconstruct details of the subaqueous volcanism that formed the back-arc basin basalts (BABB) during this event, and to discuss the relationship between volcanism and the tectonics of back-arc opening, using facies analyses based on field investigation. The study area of the southern Dewa Hills contains well-exposed basalt related to the opening of the Japan Sea. Five types of basaltic rock facies are recognized: (1) coherent basalt, (2) massive platy basalt, (3) jigsaw-fit monomictic basaltic breccia, (4) massive or stratified coarse monomictic basaltic breccia with fluidal clasts, and (5) massive or stratified fine monomictic basaltic breccia. The basaltic rocks are mainly hyaloclastite. Based on facies distributions, we infer that volcanism occurred along fissures developed mainly at the center of the study area. Given that the rocks contain many fluidal clasts, submarine lava fountaining is inferred to have been the dominant eruption style. The basaltic rocks are interpreted as the products of back-arc volcanism that occurred by tensional stress related to opening of the Japan Sea, which drove strong tectonic subsidence and active lava fountain volcanism.

  9. Petrological, magnetic and chemical properties of basalt dredged from an abyssal hill in the North-east pacific

    Science.gov (United States)

    Luyendyk, B.P.; Engel, C.G.

    1969-01-01

    OVER the years, samples of basalt from the oceanic crust have been taken mainly from seamounts, fracture zones and ridge and rise crests1-6, and rarely from the vast fields of abyssal hills which cover a large part of the deep-sea floor. The basalt sampled from the deeper regions of the oceanic crust (for example, on fault scarps) is a distinct variety of tholeiitic basalt, while alkali basalt is restricted to the volcanic edifices4. Oceanic tholeiitic basalt differs from alkali basalt and continental tholeiite chiefly in having a relatively low percentage of K2O (0.2 weight per cent)4. Some authors have speculated that this type of tholeiitic basalt is the major extrusion from the upper mantle and constitutes the predominant rock type in the upper oceanic crust. ?? 1969 Nature Publishing Group.

  10. Mineralogy, Petrology and Oxygen Fugacity of the LaPaz Icefield Lunar Basaltic Meteorites and the Origin of Evolved Lunar Basalts

    Science.gov (United States)

    Collins, S. J.; Righter, K.; Brandon, A. D.

    2005-01-01

    LAP 02205 is a 1.2 kg lunar mare basalt meteorite found in the Lap Paz ice field of Antarctica in 2002 [1]. Four similar meteorites were also found within the same region [1] and all five have a combined mass of 1.9 kg (LAP 02224, LAP 02226, LAP 02436 and LAP 03632, hereafter called the LAP meteorites). The LAP meteorites all contain a similar texture, mineral assemblage, and composition. A lunar origin for these samples comes from O isotopic data for LAP 02205 [1], Fe/Mn ratios of pyroxenes [1-5], and the presence of distinct lunar mineralogy such as Fe metal and baddeleyite. The LAP meteorites may represent an area of the Moon, which has never been sampled by Apollo missions, or by other lunar meteorites. The data from this study will be used to compare the LAP meteorites to Apollo mare basalts and lunar basaltic meteorites, and will ultimately help to constrain their origin.

  11. Underground engineering at the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1987-01-01

    A special task group was organized by the US National Committee for Rock Mechanics and the Board on Radioactive Waste Management of the National Research Council to address issues relating to the geotechnical site characterization program for an underground facility to house high-level radioactive waste of the Basalt Waste Isolation Project (BWIP). Intended to provide an overview of the geotechnical program, the study was carried out by a task group consisting of ten members with expertise in the many disciplines required to successfully complete such a project. The task group recognized from the outset that the short time frame of this study would limit its ability to address all geotechnical issues in detail. Geotechnical issues were considered to range from specific technical aspects such as in-situ testing for rock mass permeability; rock hardness testing in the laboratory; or geologic characterizations and quantification of joints, to broader aspects of design philosophy, data collection, and treatment of uncertainty. The task group chose to focus on the broader aspects of underground design and construction, recognizing that the BWIP program utilizes a peer review group on a regular basis which reviews the specific technical questions related to geotechnical engineering. In this way, it was hoped that the review provided by the task group would complement those prepared by the BWIP peer review group

  12. 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.

  13. Basalt Related to Lunar Mg-Suite Plutonic Rocks: A Fragment in Lunar Meteorite ALH 81005

    Science.gov (United States)

    Treiman, A. H.; Gross, J.

    2013-09-01

    We report on a basalt clast, in meteorite ALH 81005, which appears to be from a volcanic equivalent of an Mg-suite plutonic rock. Its mineral compositions, mineral proportions, and trace minerals are like those of Mg-norites.

  14. Basalt microlapilli in deep sea sediments of Indian Ocean in the vicinity of Vityaz fracture zone

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Iyer, S.D

    Two cores recovered from the flanks of Mid-India oceanic ridge in the vicinity of Vityaz fracture zone consist of discrete pyroclastic layers at various depths. These layers are composed of coarse-grained, angular basaltic microlapilli in which...

  15. Coupled geomechanical/hydrological modeling: an overview of basalt waste isolation project studies

    International Nuclear Information System (INIS)

    Baca, R.G.; Case, J.B.; Patricio, J.G.

    1980-07-01

    Basalt Waste Isolation Project investigations of the Columbia River basalts are multi-disciplinary in nature with a broad scope spanning such areas as geology, seismology, geochemistry, hydrology, rock mechanics, and many other disciplines as well. In this paper, an overview is presented which surveys recent work on numerical modeling of geomechanical and hydrological processes in a basalt rock environment. A major objective of the ongoing numerical modeling work is to establish a predictive technology base with which to: interpret the interrelationships between geomechanical behavior of rock media, the natural hydrologic phenomena, and repository conditions; evaluate the effectiveness of preconceptual repository designs and assist in the design of in situ field testing; and assess the waste isolation capability of candidate host rocks within the Columbia River basalts. To accomplish this objective, a systems approach has been adopted which is based on the use of digital simulation models

  16. Oxygen fugacity of basaltic magmas and the role of gas-forming elements

    Science.gov (United States)

    Sato, M.

    1978-01-01

    It is suggested that major variations in the relative oxygen fugacity of a basaltic magma are caused primarily by gas-forming elements, especially carbon and hydrogen. According to this theory, carbon, present in the source region of a basaltic magma, reduces the host magma during ascent, as isothermally carbon becomes more reducing with decreasing pressure. For an anhydrous magma such as lunar basalts, this reduction continues through the extrusive phase and the relative oxygen fugacity decreases rapidly until buffered by the precipitation of a metallic phase. For hydrous magmas such as terrestrial basalts, reduction by carbon is eventually superceded by oxidation due to loss of H2 generated by the reaction of C with H2O and by thermal dissociation of H2O. The relative oxygen fugacity of a hydrous magma initially decreases as a magma ascends from the source region and then increases until magnetite crystallization curbs the rising trend of the relative oxygen fugacity.

  17. Some aspects of the minor element chemistry of lunar mare basalts

    International Nuclear Information System (INIS)

    Ringwood, A.E.

    1975-01-01

    The principal minor element (including Ti) characteristics of mare basalts which must be explained by an acceptable theory of petrogenesis are reviewed. Recent hypotheses have proposed that mare basalts formed by equilibrium partial melting of pyroxene-rich cumulates which underlay and were complementary to the anorthositic crust. These hypotheses are examined in detail and are rejected on several grounds. A new hypothesis based upon partial melting under conditions of surface or local equilibrium is proposed. It is assumed that the moon accreted from material which had ultimately formed by fractional condensation from a gas phase of appropriate composition. A disequilibrium mineral assemblage with a bulk composition similar to that of the pyroxenite source region of mare basalts as derived from experimental petrological considerations was formed. It is considered that this model is capable of explaining the principal minor element characteristics of mare basalts and is consistent with interpretations of the major element chemistry of their source region based upon experimental petrology. (Auth.)

  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. A note on sulphide-oxide mineralisation in Carlsberg Ridge basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Pillow basalts from the Carlsberg Ridge at 3 degrees 35'N contain disseminated chalcopyrite, pyrite, and magnetite. The euhedral shape of the pyrite grains indicate them to be early formed and grown unobstructed while magnetite occurs as skeletal...

  20. Mineral chemistry of Carlsberg Ridge basalts at 3 degrees 35'- 3 degrees 41' N

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Banerjee, R.

    (approximately 91 mole %) are few and rarely zoned. The composition of plagioclase and olivine indicate low pressure equilibrium crystallization. The basalts were probably derived through fractional crystallization at shallow depths under low partial melting...

  1. Ambient noise tomography reveals basalt and sub-basalt velocity structure beneath the Faroe Islands, North Atlantic

    Science.gov (United States)

    Sammarco, Carmelo; Cornwell, David G.; Rawlinson, Nicholas

    2017-11-01

    Ambient noise tomography is applied to seismic data recorded by a portable array of seismographs deployed throughout the Faroe Islands in an effort to illuminate basalt sequences of the North Atlantic Igneous Province, as well as underlying sedimentary layers and Precambrian basement. Rayleigh wave empirical Green's functions between all station pairs are extracted from the data via cross-correlation of long-term recordings, with phase weighted stacking implemented to boost signal-to-noise ratio. Dispersion analysis is applied to extract inter-station group travel-times in the period range 0.5-15 s, followed by inversion for period-dependent group velocity maps. Subsequent inversion for 3-D shear wave velocity reveals the presence of significant lateral heterogeneity (up to 25%) in the crust. Main features of the final model include: (i) a near-surface low velocity layer, interpreted to be the Malinstindur Formation, which comprises subaerial compound lava flows with a weathered upper surface; (ii) a sharp velocity increase at the base of the Malinstindur Formation, which may mark a transition to the underlying Beinisvørð Formation, a thick laterally extensive layer of subaerial basalt sheet lobes; (iii) a low velocity layer at 2.5-7.0 km depth beneath the Beinisvørð Formation, which is consistent with hyaloclastites of the Lopra Formation; (iv) an upper basement layer between depths of 5-9 km and characterized by S wave velocities of approximately 3.2 km/s, consistent with low-grade metamorphosed sedimentary rocks; (v) a high velocity basement, with S wave velocities in excess of 3.6 km/s. This likely reflects the presence of a crystalline mid-lower crust of Archaean continental origin. Compared to previous interpretations of the geological structure beneath the Faroe Islands, our new results point to a more structurally complex and laterally heterogeneous crust, and provide constraints which may help to understand how continental fragments are rifted from the

  2. Perspectives on Ocean Ridge Basalts from the Segment to the Global Scale

    OpenAIRE

    Gale, Allison

    2012-01-01

    This study addresses the influences on ridge basalt chemistry, through analysis of their major and trace element and isotopic composition at scales ranging from individual ridge segments to the entire length of the ridge system. Local-scale studies of basalts along the Mid-Atlantic Ridge shed light on crustal accretion at slow-spreading ridges, and on the nature of plume-ridge interaction in this region. We show that segments must have multiple supplies of magma delivered along their length, ...

  3. Mineralogy, geochemistry and expansion testing of an alkali-reactive basalt from western Anatolia, Turkey

    International Nuclear Information System (INIS)

    Copuroglu, Oguzhan; Andic-Cakir, Ozge; Broekmans, Maarten A.T.M.; Kuehnel, Radko

    2009-01-01

    In this paper, the alkali-silica reaction performance of a basalt rock from western Anatolia, Turkey is reported. It is observed that the rock causes severe gel formation in the concrete microbar test. It appears that the main source of expansion is the reactive glassy phase of the basalt matrix having approximately 70% of SiO 2 . The study presents the microstructural characteristics of unreacted and reacted basalt aggregate by optical and electron microscopy and discusses the possible reaction mechanism. Microstructural analysis revealed that the dissolution of silica is overwhelming in the matrix of the basalt and it eventually generates four consequences: (1) Formation of alkali-silica reaction gel at the aggregate perimeter, (2) increased porosity and permeability of the basalt matrix, (3) reduction of mechanical properties of the aggregate and (4) additional gel formation within the aggregate. It is concluded that the basalt rock is highly prone to alkali-silica reaction. As an aggregate, this rock is not suitable for concrete production.

  4. The investigation of gamma and neutron shielding properties of concrete including basalt fibre for nuclear energy applications

    International Nuclear Information System (INIS)

    Nulk, H.; Ipbuker, C.; Gulik, V.; Tkaczyk, A.; Biland, A.

    2015-01-01

    In this study, we would like to draw attention to the prospect of basalt fibre as the main component for concrete reinforcement of NPP. This work describes the computational study of gamma attenuation parameters, the effective atomic number Z(eff) and the effective electron density N e (eff), of relatively light-weight concrete with chopped basalt fibre used as reinforcement in different mixture rates. We can draw the following conclusions. Basalt fibre is a relatively cheap material that can be used as reinforcement instead of metallic fibers. Basalt fibre has a similar specific gravity to that of concrete elements. Basalt fibre has high chemical and abrasion resistance. Basalt fibre has almost 10 times the tensile strength of steel re-bars. Gamma-ray attenuation coefficients increase with addition of basalt fibre into concrete in every case. The effective atomic number of the concrete increases with the addition of basalt fibre. The results show that basalt fibre reinforced concrete have improved shielding properties against gamma rays in comparison with regular concrete. This result is based on a regular concrete with only basalt fiber reinforcement. We estimate that with addition of standard aggregates for radiation shielding concrete, such as barite, magnetite or hematite, the shielding properties will increase exponentially

  5. Calcites from Ocean Crust Basalts: Reliable Proxy Archives?

    Science.gov (United States)

    Böhm, Florian; Eisenhauer, Anton

    2017-04-01

    Calcite cements in ocean crust basalts of the deep sea form from mixtures of cold seawater and warm hydrothermal fluids (about 0-70°C). These low temperature alteration (LTA) calcites have recently gained new interest as proxy recorders of seawater composition (Refs. 1-5). Recent LTA calcite reconstructions of the Sr/Ca and Mg/Ca evolution in ocean waters point to considerably lower Sr/Ca and Mg/Ca ratios during the Cretaceous and Paleogene than in the modern ocean. However, diagenetic alteration in contact with the basalt host rock may change the composition of the LTA calcites. For testing the reliability of LTA calcite records of seawater composition multi-proxy approaches are applied: oxygen isotopes indicate precipitation temperatures, strontium isotopes (87Sr/86Sr) and trace elements indicate influences from hydrothermal fluids. Additional information about the influence of basement rocks on LTA calcite composition can be derived from analyses of stable calcium and strontium isotopes (44/40Ca, 88/86Sr). We find low 44/40Ca values for DSDP and ODP sites where the 87Sr/86Sr ratios of LTA calcites indicate basement influence. On the other hand, for some sites the 87Sr/86Sr values inidicate precipitation from pristine seawater, while low 44/40Ca values indicate basement influence. All of these sites are either older than 50 Myr or show calcite precipitation temperatures >50°C. Sites that are younger than 25 Myr and had formation temperatures 50°C significantly higher 88/86Sr values were observed. The calcium isotope results indicate basement influence on LTA calcite composition at temperatures >10°C. Radiogenic strontium isotopes, in contrast, can be used as unequivocal basement influence indicators only at temperatures above 30°C. Below about 20°C 87Sr/86Sr ratios are no reliable indicators of basement influence. All LTA calcites of sites older than 50 Myr formed (or recrystallized) at temperatures >15°C. Low 44/40Ca values indicate that

  6. Like a cannonball: origin of dense spherical basaltic ejecta

    Science.gov (United States)

    Di Piazza, Andrea; Del Bello, Elisabetta; Mollo, Silvio; Vona, Alessandro; Alvarado, Guillermo E.; Masotta, Matteo

    2017-05-01

    Cannonballs are rare spherical to sub-spherical eruptive products associated with basaltic explosive activity. The origin of cannonballs is still debated and subjected to a wide spectrum of different interpretations. In order to better understand the physicochemical mechanisms controlling the formation of these explosive products, we investigated the textural and chemical features of cannonballs from the Cerro Chopo monogenetic volcano (Costa Rica). These explosive products ubiquitously show a core domain with coalesced bubbles (30-36% porosity) wrapped in a dense rim domain with small, isolated bubbles (20-27% porosity). Both domains are identical in terms of bulk rock composition and mineral chemistry and are portions of the same magma batch. Results from combined petrological and thermodynamic modeling indicate that a low-viscosity ( 20 Pa s) melt containing early-formed olivine phenocrysts ( 9 vol.%) ascended from storage at a decompression rate of 0.5 MPa s-1 until it reached a depth of 4.5 km (equivalent to a pressure of 150 MPa). While rising from depth to 4.5 km, the melt underwent rapid decompression (0.5-2.6 MPa s-1) and H2O exsolution, driving late-stage crystallization of the groundmass. The fast ascent velocity (21-110 m s-1) while rising between 4.5 km and the surface induced turbulent (Re >103), annular flow development in the uppermost region of the conduit. We propose that cannonballs represent blebs of fluid magmas that underwent shear-driven detachment from the annulus of magma lining the conduit walls at depths lower than 4.5 km. The formation of such cannonballs is dictated by magma transport dynamics of low-viscosity, phenocryst-poor, and volatile-rich melts that rapidly accelerate within the shallow conduit.

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

    Science.gov (United States)

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

    2017-04-01

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

  8. Geochemical insights into the lithology of mantle sources for Cenozoic alkali basalts in West Qinling, China

    Science.gov (United States)

    Dai, Li-Qun; Zheng, Fei; Zhao, Zi-Fu; Zheng, Yong-Fei

    2018-03-01

    Although alkali basalts are common in oceanic islands and continental rifts, the lithology of their mantle sources is still controversial. While the peridotite is usually viewed as a common source lithology, there are increasing studies suggesting significant contributions from ultramafic metasomatites such as carbonated peridotite, pyroxenite and hornblendite to the origin of alkali basalts. The present study indicates that carbonated peridotite plus hornblendite would have served as the mantle sources of Cenozoic alkali basalts from the West Qinling orogen in China. The target basalts show low SiO2 contents of 36.9 to 40.8 wt% and highly variable Na2O + K2O contents from 0.86 to 4.77 wt%, but high CaO contents of 12.5 to 16.3 wt% and CaO/Al2O3 ratios of 1.42 to 2.19. They are highly enriched in the majority of incompatible trace elements, but depleted in Rb, K, Pb, Zr, Hf, and Ti. Furthermore, they exhibit high (La/Yb)N, Zr/Hf, Ce/Pb and Nb/Ta ratios, but low Ti/Eu and Hf/Sm ratios. Generally, with increasing (La/Yb)N and CaO/Al2O3 ratios, their Ti/Eu and Hf/Sm ratios decrease whereas their Zr/Hf, Ce/Pb and Nb/Ta ratios increase. These major and trace element features are similar to those of carbonatites and hornblendite-derived melts to some extent, but significantly different from those of mid-ocean ridge basalts (MORB). This suggests that the alkali basalts would be originated from metasomatic mantle sources. A comparison of the major-trace elements in the alkali basalts with those of some representative mantle-derived melts indicates that the source lithology of alkali basalts is a kind of ultramafic metasomatites that are composed of carbonated peridotite and hornblendite. Such metasomatites would be generated by reaction of the depleted MORB mantle peridotite with hydrous, carbonate-bearing felsic melts derived from partial melting of the subducted Paleotethyan oceanic crust. Therefore, the melt-peridotite reaction at the slab-mantle interface in the

  9. 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.

  10. A chemical model for generating the sources of mare basalts - Combined equilibrium and fractional crystallization of the lunar magmasphere

    Science.gov (United States)

    Snyder, Gregory A.; Taylor, Lawrence A.; Neal, Clive R.

    1992-01-01

    A chemical model for simulating the sources of the lunar mare basalts was developed by considering a modified mafic cumulate source formed during the combined equilibrium and fractional crystallization of a lunar magma ocean (LMO). The parameters which influence the initial LMO and its subsequent crystallization are examined, and both trace and major elements are modeled. It is shown that major elements tightly constrain the composition of mare basalt sources and the pathways to their creation. The ability of this LMO model to generate viable mare basalt source regions was tested through a case study involving the high-Ti basalts.

  11. The relationship of seismic velocity structure and surface fracture characteristics of basalt outcrops to rippability estimates

    International Nuclear Information System (INIS)

    Kay, S.E.; Dougherty, M.E.; Pelton, J.R.

    1994-01-01

    Seismic velocity has been shown in previous engineering studies to be related to the fracture characteristics and rippability of rock outcrops. However, common methods of measuring seismic velocity in outcrops do not take into account the many possible travel paths for wave propagation and the fact that velocity zones may exist within an outcrop. Presented here are the results of using raytracing inversion of first-arrival travel-time data to map P-velocity structure in basalt outcrops, and also the investigation of the relationship of the mapped velocities to observed surface fractures and hand-sample P-velocities. It is shown that basalt outcrops commonly consist of an irregular near-surface low-velocity zone underlain by higher velocity material; that velocity gradients can exist in outcrops; that hand-sample velocity measurements are typically higher than outcrop-scale measurements; and that the characteristics of surface fractures are empirically related to near-surface P-velocity. All of these findings are relevant to the estimated rippability of rock in geotechnical engineering. The data for this study are derived from eleven sites on basalt outcrops of the Troodos Ophiolite in Cyprus. The basalt types include pillow basalts, massive flows, and a pillow breccia. A commonly available raytracing inversion program (RAYINVR) was used to produce a velocity profile of each outcrop. Different velocity zones were detailed by inverting observed travel times to produce a model of outcrop velocity structure which produces rippability profiles for each outcrop. 16 refs., 9 figs

  12. Zircon evidence for incorporation of terrigenous sediments into the magma source of continental basalts.

    Science.gov (United States)

    Xu, Zheng; Zheng, Yong-Fei; Zhao, Zi-Fu

    2018-01-09

    Crustal components may be incorporated into continental basalts by either shallow contamination or deep mixing. While the former proceeds at crustal depths with common preservation of refractory minerals, the latter occurs at mantle depths with rare survival of relict minerals. Discrimination between the two mechanisms has great bearing to subcontinental mantle geochemistry. Here we report the occurrence of relict zircons in Cenozoic continental basalts from eastern China. A combined study of zircon U-Pb ages and geochemistry indicates that detrital zircons were carried by terrigenous sediments into a subcontinental subduction zone, where the zircon were transferred by fluids into the magma sources of continental basalts. The basalts were sampled from three petrotectonic units with distinct differences in their magmatic and metamorphic ages, making the crustal contamination discernible. The terrigenous sediments were carried by the subducting oceanic crust into the asthenospheric mantle, producing both soluble and insoluble materials at the slab-mantle interface. These materials were served as metasomatic agents to react with the overlying mantle wedge peridotite, generating a kind of ultramafic metasomatites that contain the relict zircons. Therefore, the occurrence of relict zircons in continental basalts indicates that this refractory mineral can survive extreme temperature-pressure conditions in the asthenospheric mantle.

  13. Performance of basaltic dust issued from an asphaltic plant as a flocculant additive for wastewater treatment.

    Science.gov (United States)

    Ramírez Zamora, R M; Chávez Mejia, A; Domínguez Mora, R; Durán Moreno, A

    2004-01-01

    The feasibility of using basaltic dust as a flocculant additive or coagulant aid for wastewater treatment was assessed in this research. The experimental study was divided into two stages: 1) physicochemical characterisation of the basaltic dust by applying standardised techniques, and 2) evaluation of this material as flocculant additive for the coagulation-flocculation of wastewater treated for reuse. Coagulation-flocculation experiments were carried out in the laboratory with a mixture of industrial and municipal wastewater samples collected from two points of the final discharge of the Mexico City sewerage system. Aluminium sulphate and lime were used as coagulants and the basaltic dust as flocculant additive, by applying the jar-test technique. The results of the corrosivity, reactivity, explosiveness, toxicity, inflammability and biological risk tests indicated that this material is classified as a non-hazardous waste (according to the Mexican legislation, NOM-052-ECOL-1993). The density, oxide content and particle size values of basaltic dust were similar to those reported for the flocculant additive denominated activated silica. The jar test results showed a positive effect of basaltic dust over the effluent and sludge qualities, to the extent that coagulant doses can be reduced 30% (from 150 mg/L to 110 mg/L of Al2(SO4)3).

  14. Hydrogeological and quantitative groundwater assessment of the Basaltic Aquifer, Northern Harrat Rahat, Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Shaibani, A.; Abokhodair, Abdulwahab A.; Lloyd, J.W.; Al-Ahmari, A.

    2007-01-01

    The Northern Harrat Rahat consists of 300m basalt lavas covering some 2000 km2 to the south-east of Al-Madinah in western Saudi Arabia. Like many basalt sequences, the Rahat basalts form an important aquifer and groundwater resource. The aquifer has a saturated thickness of up to 60m and made up of the weathered upper part of underlying basement, pre-basalt sands and gravels and the fractured basalts. Since 1992, groundwater has been abstracted from the aquifer as part of the Al-Madinah water supply. To assess the potential of the aquifer an assessment has been made based on pumping tests of 70 wells. The hydraulic parameters have been shown to be highly variable typical of the fractured domain. The aquifer contains good-quality water in storage, but receives limited recharge. Groundwater temperature anomalies indicate remnant volcanic activity locally. A numerical groundwater model has been constructed, which has been calibrated using limited groundwater head measurements, but with good abstraction records. Prediction of groundwater heads and the examination of several abstraction scenarios indicate that the aquifer can continue to support part of the Al-Madinah demand for the next several years, if certain well distributions are adopted. The predictions also show that the aquifer can only support the total demand of the city for a few days as a contingency resource. (author)

  15. 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%.

  16. 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.

  17. Studies of Basalt Through Laser Induced Breakdown Spectroscopy (LIBS for the Manufacturing of Lapilli Blocks

    Directory of Open Access Journals (Sweden)

    Ismael De la Viuda-Pérez

    2016-10-01

    Full Text Available Basaltic samples selected from different areas of Tenerife were analyzed by applying laser induced breakdown spectroscopy (LIBS, Raman spectroscopy and X Ray Diffraction (XRD in order to identify the basic chemical composition and mineralogy. The basic composition obtained from the analysis was: O, F, Na, K, Mg, Al Si, Ca, Ti and Fe. Raman spectroscopic and XRD analyses indicated a basaltic mineralogy which is consistent with the basic composition results obtained from LIBS. The results of the analyses carried out using portable instrumentation proved the suitability of the LIBS, specially combined with the Raman spectroscopy for their application in the mineralogical-chemical identification in the areas where basalts and lapilli are extracted for construction works in Tenerife.

  18. Bibliography of geologic studies: Columbia Plateau (Columbia River Basalt) and adjacent areas in Idaho

    International Nuclear Information System (INIS)

    Strowd, W.

    1978-11-01

    The objective of this compilation is to present a comprehensive listing of published, unpublished, and open-file references pertaining to the geology of the Columbia Plateau and adjacent areas in the State of Idaho. The bibliography was compiled in support of Rockwell's Basalt Waste Isolation Program that is evaluating the feasibility of nuclear waste storage in the Columbia River Basalt Group. The emphasis is on stratigraphy, structural geology, seismicity, and tectonics, although the nature of Columbia River Basalt distribution in Idaho has necessitated the inclusion of a sizeable collection of references on geology marginal to the Columbia Plateau and associated mineral resources. The bibliography is divided into two major sections, the alphabetical listing of all references and the subject index. The subject index is divided into 19 categories to facilitate locating a specific reference in the user's field of interest

  19. 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.

  20. 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.

  1. High-level waste-basalt interactions. Annual progress report, February 1, 1977--September 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, G.J.; Scheetz, B.E.

    1978-05-01

    Commercial radioactive waste can be placed under ground in a basalt repository to contain significant amounts of radioactive decay heat for the first hundred or so years, which constitutes the ''thermal period'' of waste isolation, if the feasibility is determined that a basalt geology is a suitable medium for storage of radioactive wastes. Several physical-chemical changes analogous to natural geochemical processes can occur in and around this repository during the thermal period. The waste canister can act as a heat source and cause changes in the mineralogy and properties of the surrounding basalts. Geochemically, this is ''contact metamorphism.'' This phenomenon needs to be investigated because it could affect the behavior of the basalt with regard to migration of long-lived radionuclides away from the immediate repository. It is well known that even the relatively low-grade hydrothermal conditions possible in the repository (temperatures up to 400 degrees Centigrade; pressures up to 300 bars) can cause extensive modifications in rocks and minerals. At the end of the thermal period, the residue of the original waste plus the waste-basalt interaction products would constitute the actual waste form (or ''source term'') subject to the low-temperature leaching and migration processes under investigation in other laboratories. During the last eight months of fiscal year 1977, a program was initiated at The Pennsylvania State University which had as its objective the determination of the nature and implication of any chemical or mineralogical changes in, or interactions between, each candidate radioactive waste form and representative Columbia River Basalt under the various relevant repository conditions during the thermal period. Results of these investigations are given.

  2. High-level waste-basalt interactions. Annual progress report, February 1, 1977--September 30, 1977

    International Nuclear Information System (INIS)

    McCarthy, G.J.; Scheetz, B.E.

    1978-05-01

    Commercial radioactive waste can be placed under ground in a basalt repository to contain significant amounts of radioactive decay heat for the first hundred or so years, which constitutes the ''thermal period'' of waste isolation, if the feasibility is determined that a basalt geology is a suitable medium for storage of radioactive wastes. Several physical-chemical changes analogous to natural geochemical processes can occur in and around this repository during the thermal period. The waste canister can act as a heat source and cause changes in the mineralogy and properties of the surrounding basalts. Geochemically, this is ''contact metamorphism.'' This phenomenon needs to be investigated because it could affect the behavior of the basalt with regard to migration of long-lived radionuclides away from the immediate repository. It is well known that even the relatively low-grade hydrothermal conditions possible in the repository (temperatures up to 400 degrees Centigrade; pressures up to 300 bars) can cause extensive modifications in rocks and minerals. At the end of the thermal period, the residue of the original waste plus the waste-basalt interaction products would constitute the actual waste form (or ''source term'') subject to the low-temperature leaching and migration processes under investigation in other laboratories. During the last eight months of fiscal year 1977, a program was initiated at The Pennsylvania State University which had as its objective the determination of the nature and implication of any chemical or mineralogical changes in, or interactions between, each candidate radioactive waste form and representative Columbia River Basalt under the various relevant repository conditions during the thermal period. Results of these investigations are given

  3. Hydrochemistry and hydrogeologic conditions within the Hanford Site upper basalt confined aquifer system

    Energy Technology Data Exchange (ETDEWEB)

    Spane, F.A. Jr.; Webber, W.D.

    1995-09-01

    As part of the Hanford Site Ground-Water Surveillance Project, Flow System Characterization Task. Pacific Northwest Laboratory examines the potential for offsite migration of contamination within the upper basalt confined aquifer system for the US Department of Energy (DOE). As part of this activity, groundwater samples were collected over the past 2 years from selected wells completed in the upper Saddle Mountains Basalt. The hydrochemical and isotopic information obtained from these groundwater samples provides hydrologic information concerning the aquifer-flow system. Ideally, when combined with other hydrologic property information, hydrochemical and isotopic data can be used to evaluate the origin and source of groundwater, areal groundwater-flow patterns, residence and groundwater travel time, rock/groundwater reactions, and aquifer intercommunication for the upper basalt confined aquifer system. This report presents the first comprehensive Hanford Site-wide summary of hydrochemical properties for the upper basalt confined aquifer system. This report provides the hydrogeologic characteristics (Section 2.0) and hydrochemical properties (Section 3.0) for groundwater within this system. A detailed description of the range of the identified hydrochemical parameter subgroups for groundwater in the upper basalt confined aquifer system is also presented in Section 3.0. Evidence that is indicative of aquifer contamination/aquifer intercommunication and an assessment of the potential for offsite migration of contaminants in groundwater within the upper basalt aquifer is provided in Section 4.0. The references cited throughout the report are given in Section 5.0. Tables that summarize groundwater sample analysis results for individual test interval/well sites are included in the Appendix.

  4. 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).

  5. Hydrologic bibliography of the Columbia River basalts in Washington with selected annotations

    International Nuclear Information System (INIS)

    Tanaka, H.; Wildrick, L.; Pearson, B.

    1979-08-01

    The objective of this compilation is to present a comprehensive listing of the published, unpublished, and open file references pertaining to the surface and subsurface hydrology of the Columbia River basalts within the State of Washington and is presented in support of Rockwell's hydrologic data compilation effort for the Basalt Waste Isolation Program. A comprehensive, annotated bibliography of the Pasco Basin (including the Hanford Site) hydrology has been prepared for Rockwell as part of the Pasco Basin hydrology studies. In order to avoid unnecessary duplication, no effort was made to include a complete list of bibliographic references on Hanford in this volume

  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 fibers and the surrounding media (high humidity or water at 70 C) leads to chemical changes strongly affecting the surface morphology. The crystallization peak temperature of the basaltic glass fibers are increased without changing the onset temperature, this may be caused by a chemical depletion...

  7. Determination of Geochemical Bio-Signatures in Mars-Like Basaltic Environments

    Directory of Open Access Journals (Sweden)

    Karen Olsson-Francis

    2017-09-01

    Full Text Available Bio-signatures play a central role in determining whether life existed on early Mars. Using a terrestrial basalt as a compositional analog for the martian surface, we applied a combination of experimental microbiology and thermochemical modeling techniques to identify potential geochemical bio-signatures for life on early Mars. Laboratory experiments were used to determine the short-term effects of biota on the dissolution of terrestrial basalt, and the formation of secondary alteration minerals. The chemoorganoheterotrophic bacterium, Burkholderia sp. strain B_33, was grown in a minimal growth medium with and without terrestrial basalt as the sole nutrient source. No growth was detected in the absence of the basalt. In the presence of basalt, during exponential growth, the pH decreased rapidly from pH 7.0 to 3.6 and then gradually increased to a steady-state of equilibrium of between 6.8 and 7.1. Microbial growth coincided with an increase in key elements in the growth medium (Si, K, Ca, Mg, and Fe. Experimental results were compared with theoretical thermochemical modeling to predict growth of secondary alteration minerals, which can be used as bio-signatures, over a geological timescale. We thermochemically modeled the dissolution of the basalt (in the absence of biota in very dilute brine at 25°C, 1 bar; the pH was buffered by the mineral dissolution and precipitation reactions. Preliminary results suggested that at the water to rock ratio of 1 × 107, zeolite, hematite, chlorite, kaolinite, and apatite formed abiotically. The biotic weathering processes were modeled by varying the pH conditions within the model to adjust for biologic influence. The results suggested that, for a basaltic system, the microbially-mediated dissolution of basalt would result in “simpler” secondary alteration, consisting of Fe-hydroxide and kaolinite, under conditions where the abiotic system would also form chlorite. The results from this study demonstrate

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

    International Nuclear Information System (INIS)

    Nerilli, Francesca; Vairo, Giuseppe

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-08

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

  10. Hydrologic bibliography of the Columbia River basalts in Washington with selected annotations

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H.; Wildrick, L.; Pearson, B.

    1979-08-01

    The objective of this compilation is to present a comprehensive listing of the published, unpublished, and open file references pertaining to the surface and subsurface hydrology of the Columbia River basalts within the State of Washington and is presented in support of Rockwell's hydrologic data compilation effort for the Basalt Waste Isolation Program. A comprehensive, annotated bibliography of the Pasco Basin (including the Hanford Site) hydrology has been prepared for Rockwell as part of the Pasco Basin hydrology studies. In order to avoid unnecessary duplication, no effort was made to include a complete list of bibliographic references on Hanford in this volume.

  11. Solubility and partitioning of Ne, Ar, Kr, and Xe in minerals and synthetic basaltic melts

    Science.gov (United States)

    Broadhurst, C. L.; Drake, M. J.; Hagee, B. E.; Bernatowicz, T. J.

    1992-01-01

    The solubilities of Ne, Ar, Kr, and Xe gases were measured in natural samples of anorthite, diopside, forsterite, spinel, and synthetic basaltic melts, the samples which represent equilibrium pairs in the Fo-An-Di-SiO2 system. Results show that, in natural minerals, the solubilities of these gases increase with increasing atomic number. In contrast, the solubilities of noble gases in the synthetic basaltic melts decreased with increasing atomic number. The partition coefficients increased with increasing atomic number for all mineral/melt pairs.

  12. Basalts as probes of planetary interiors: constraints on the chemistry and mineralogy of their source regions

    International Nuclear Information System (INIS)

    Bence, A.E.; Grove, T.L.; Papike, J.J.

    1980-01-01

    Basalt magmas, derived by the partial melting of planetary interiors, have compositions that reflect the pre-accretionary history of the material from which the planet formed, the planets, subsequent evolutionary history, the chemistry and mineralogy of the source regions, and the intensive thermodynamic parameters operating at the source and emplacement sites. Studies of basalt suites from the Earth, its Moon, and the eucrite parent body reveal compositional differences intrinsic to their source regions which are, in turn, a characteristic of the planet and its formational and evolutionary history. (Auth.)

  13. 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.

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

    Science.gov (United States)

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

    2010-05-01

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

  15. 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

    We 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.

  16. 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.

  17. 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 ...

  18. From initiation to termination: a petrostratigraphic tour of the Ethiopian Low-Ti Flood Basalt Province

    Science.gov (United States)

    Krans, S. R.; Rooney, T. O.; Kappelman, J.; Yirgu, G.; Ayalew, D.

    2018-05-01

    Continental flood basalts (CFBs), thought to preserve the magmatic record of an impinging mantle plume head, offer spatial and temporal insights into melt generation processes in large igneous provinces (LIPs). Despite the utility of CFBs in probing mantle plume composition, these basalts typically erupt fractionated compositions, suggestive of significant residence time in the continental lithosphere. The location and duration of residence within the lithosphere provide additional insights into the flux of plume-related magmas. The NW Ethiopian plateau offers a well-preserved stratigraphic sequence from flood basalt initiation to termination, and is thus an important target for study of CFBs. This study examines modal observations within a stratigraphic framework and places these observations within the context of the magmatic evolution of the Ethiopian CFB province. Data demonstrate multiple pulses of magma recharge punctuated by brief shut-down events, with initial flows fed by magmas that experienced deeper fractionation (lower crust). Broad changes in modal mineralogy and flow cyclicity are consistent with fluctuating changes in magmatic flux through a complex plumbing system, indicating pulsed magma flux and an overall shallowing of the magmatic plumbing system over time. The composition of plagioclase megacrysts suggests a constant replenishing of new primitive magma recharging the shallow plumbing system during the main phase of volcanism, reaching an apex prior to flood basalt termination. The petrostratigraphic data sets presented in this paper provide new insight into the evolution of a magma plumbing system in a CFB province.

  19. 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.

  20. Absolute palaeointensity study of the Mono Lake excursion recorded by New Zealand basalts

    Science.gov (United States)

    Cassidy, John; Hill, Mimi J.

    2009-02-01

    One of the geomagnetic excursions recorded in basalts of the Auckland volcanic field, New Zealand, has recently been correlated unequivocally with the Mono Lake excursion, making it the only confirmed record from the southern hemisphere. This record is also exceptional in occurring in five separate monogenetic basaltic volcanoes. Absolute palaeointensity determinations using the microwave technique, based on a comprehensive suite of samples of the Auckland basalts recording the excursion, show that the geomagnetic field in New Zealand at the time of the Mono Lake excursion was reduced to about 14 μT i.e. to 30% of its normal value. This result confirms previous estimates based on more limited sampling. In addition, it provides a comparison of the microwave and LDT-DHT Shaw methods of measuring palaeointensity, which give results that are statistically indistinguishable. The palaeointensities determined from the five different volcanoes are also indistinguishable, though the palaeodirection data suggest that a very small segment of the VGP path may have been recorded. This study confirms the reliability of palaeointensity and palaeodirection determinations from these particular New Zealand basalts, which together with their definitive 40Ar/ 39Ar ages, establishes this record of the Mono Lake excursion as one of the best documented. Consequently, there is significant potential in searching for records of this excursion elsewhere in the Pacific region for use as a stratigraphic marker in studies of recent volcanism and palaeoclimate reconstructions.

  1. 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 of t...

  2. Upper Basalt-Confined Aquifer System in the Southern Hanford Site

    International Nuclear Information System (INIS)

    Thorne, P.

    1999-01-01

    The 1990 DOE Tiger Team Finding GW/CF-202 found that the hydrogeologic regime at the Hanford Site was inadequately characterized. This finding also identified the need for completing a study of the confined aquifer in the central and southern portions of the Hanford Site. The southern portion of the site is of particular interest because hydraulic-head patterns in the upper basalt-confined aquifer system indicate that groundwater from the Hanford central plateau area, where contaminants have been found in the aquifer, flows southeast toward the southern site boundary. This results in a potential for offsite migration of contaminants through the upper basalt-confined aquifer system. Based on the review presented in this report, available hydrogeologic characterization information for the upper basalt-confined aquifer system in this area is considered adequate to close the action item. Recently drilled offsite wells have provided additional information on the structure of the aquifer system in and near the southern part of the Hanford Site. Information on hydraulic properties, hydrochemistry, hydraulic heads and flow directions for the upper basalt-confined aquifer system has been re-examined and compiled in recent reports including Spane and Raymond (1993), Spane and Vermeul ( 1994), and Spane and Webber (1995)

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

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

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

  4. Coevolution of hydrology and topography on a basalt landscape in the Oregon Cascade Range, USA

    Science.gov (United States)

    A. Jefferson; G.E. Grant; S.L. Lewis; S.T. Lancaster

    2010-01-01

    Young basalt terrains offer an exceptional opportunity to study landscape and hydrologic evolution through time, as the age of the landscape itself can be determined by dating lava flows. These constructional terrains are also highly permeable, allowing one to examine timescales and process of geomorphic evolution as they relate to the partitioning of hydrologic...

  5. Physiological and morphological characterization of basalt milkvetch (Astragalus filipes): Basis for plant improvement

    Science.gov (United States)

    Kishor Bhattarai; Douglas A. Johnson; Thomas A. Jones; Kevin J. Connors; Dale R. Gardner

    2008-01-01

    Astragalus filipes Torr. ex A. Gray (basalt milkvetch or threadstalk milkvetch) is a legume that is widely distributed in western North America andholds promise for revegetation and restoration programs in the western United States. Seed of 67 accessions was collected in 2003 from Utah, Nevada, Idaho, Oregon, California, and Washington. Field-collected forage samples...

  6. 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; Wang, Xin; 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 1000 deg C. Polycarbosilane, an organosilicon polymer, contain a silicon-carbon backbone; around 1200 deg C, 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.

  7. Low-Ti basalts from the Faroe Islands constrain the early Iceland depleted plume component

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin

    New Sr, Nd, Hf and high precision Pb isotope analyses of 46 Faroese low-Ti lavas erupted at the rifting of the proto-North Atlantic ~56-55 Ma ago are presented. The low-Ti lavas are depleted, MORB-like basalts erupted close to the riftzone at the same time as enriched high-Ti basalts were erupted...... of the magmas. However, 5 of the samples show signs of mixing with high-Ti melts. Although highly sensitive to crustal contamination, only little is detected in the low-Ti basalts. Isotopically the low-Ti basalts can be explained by mixing of the two end-members DM (the local depleted mantle as defined...... by the sample array) and NAEM (North Atlantic End-Member) (Ellam & Stuart 2000). The NAEM component is very similar to the Icelandic depleted plume component ID1 (Thirlwall et al. 2004) and both have negative ¿207Pb, low 206Pb/204Pb and eNd and high 87Sr/86Sr compared to MORB. Therefore the NAEM component could...

  8. 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

    to the most radiogenic values found in recent Icelandic basalts. Furthermore, the main volume of lavas in East Greenland is displaced away from the NAEM towards this radiogenic Pb component. Thus, this ‘Iceland radiogenic Pb end-member’ component was a significant contributor to the break-up-related magmatism...

  9. Overview of hydrothermal testing of waste-package barrier materials at the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1982-01-01

    The current Waste Package Department (WPD) hydrothermal testing program for the Basalt Waste Isolation Project (BWIP) has followed a systematic approach for the testing of waste-barrier-basalt interactions based on sequential penetration of barriers by intruding groundwaters. Present test activities in the WPD program have focused on determining radionuclide solubility limits (or steady-state conditions) of simulated waste forms and the long-term stability of waste package barriers under site-specific hydrothermal conditions. The resulting data on solution compositions and solid alteration products have been used to evaluate waste form degradation under conditions specific to a nuclear waste repository located in basalt (NWRB). Isothermal, time-invariant compositional data on sampled solutions have been coupled with realistic hydrologic flow data for near-field and far-field modeling for the calculation of meaningful radionuclide release rates. Radionuclides that are not strongly sorbed or precipitated from solution and that, therefore, may require special attention to ensure their isolation within the waste package have been identified. Taken together, these hydrothermal test data have been used to establish design requirements for waste packages located in basalt

  10. Characterization and petrologic interpretation of olivine-rich basalts at Gusev Crater, Mars

    Science.gov (United States)

    McSween, H.Y.; Wyatt, M.B.; Gellert, Ralf; Bell, J.F.; Morris, R.V.; Herkenhoff, K. E.; Crumpler, L.S.; Milam, K.A.; Stockstill, K.R.; Tornabene, L.L.; Arvidson, R. E.; Bartlett, P.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; Clark, B. C.; Crisp, J.A.; Des Marais, D.J.; Economou, T.; Farmer, J.D.; Farrand, W.; Ghosh, A.; Golombek, M.; Gorevan, S.; Greeley, R.; Hamilton, V.E.; Johnson, J. R.; Joliff, B.L.; Klingelhofer, G.; Knudson, A.T.; McLennan, S.; Ming, D.; Moersch, J.E.; Rieder, R.; Ruff, S.W.; Schrorder, C.; de Souza, P.A.; Squyres, S. W.; Wanke, H.; Wang, A.; Yen, A.; Zipfel, J.

    2006-01-01

    Rocks on the floor of Gusev crater are basalts of uniform composition and mineralogy. Olivine, the only mineral to have been identified or inferred from data by all instruments on the Spirit rover, is especially abundant in these rocks. These picritic basalts are similar in many respects to certain Martian meteorites (olivine-phyric shergottites). The olivine megacrysts in both have intermediate compositions, with modal abundances ranging up to 20-30%. Associated minerals in both include low-calcium and high-calcium pyroxenes, plagioclase of intermediate composition, iron-titanium-chromium oxides, and phosphate. These rocks also share minor element trends, reflected in their nickel-magnesium and chromium-magnesium ratios. Gusev basalts and shergottites appear to have formed from primitive magmas produced by melting an undepleted mantle at depth and erupted without significant fractionation. However, apparent differences between Gusev rocks and shergottites in their ages, plagioclase abundances, and volatile contents preclude direct correlation. Orbital determinations of global olivine distribution and compositions by thermal emission spectroscopy suggest that olivine-rich rocks may be widespread. Because weathering under acidic conditions preferentially attacks olivine and disguises such rocks beneath alteration rinds, picritic basalts formed from primitive magmas may even be a common component of the Martian crust formed during ancient and recent times. Copyright 2006 by the American Geophysical Union.

  11. Apollo 12 feldspathic basalts 12031, 12038, and 12072; petrology, comparison and interpretations

    International Nuclear Information System (INIS)

    Beaty, E.W.; Hill, S.M.R.; Albee, A.L.; Baldridge, W.S.

    1979-01-01

    Modal and chemical data indicate that 12072, 12038, and 12031, the Apollo 12 feldspathic basalts, form a well-defined group which cannot be related to the other Apollo 12 rock types. 12072 contains phenocrysts of olivine and pigeonite and microphenocrysts of Cr-spinel set in a fine-grained, variolitic groundmass. 12038 is a medium-grained, equigranular basalt with a texture indicating it was multiply saturated. 12031 is a coarse-grained rock with granular to graphic intergrowths of pyroxene and plagioclase; it was also multiply saturated. Petrologic observations, as well as the bulk chemistry, are consistent with the interpretation that 12031 could be derived from 12072 through fractionation of Cr-spinel, olivine, and pigeonite, the observed phenocryst assemblage. 12038, however, contains more pigeonite, less olivine, three times as much Ca-phosphate minerals, one-fifth as much troilite, and much more sodic plagioclase than 12072. These differences indicate that 12038 must have come from a separate igneous body. Consideration of the bulk compositions indicates that neither 12072 and 12031 nor 12038 could have been derived from the Apollo 12 olivine, pigeonite, or ilmenite basalts by crystal--liquid fractionation. The general petrologic similarities between 12072, 12031, and the other Apollo 12 basalts suggests that they were produced in either the same or similar source regions. 12038, however, is petrologically and chemically unique, and is probably exotic to the Apollo 12 landing site

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

    Indian Academy of Sciences (India)

    It also evaluates band ratios and fusion techniques for mapping purposes using ASTER data. Several volcanic episodes occurred during Early- to Late-. Cretaceous are recorded in the study area. Early-Cretaceous olivine basalts are highly carbonated. Late-. Cretaceous eruptions took place throughout several volcanic ...

  13. 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.

  14. Chronology and isotopic geochemistry of Apollo 14 basalts and Skaergard Gabbro, Eastern Greenland

    International Nuclear Information System (INIS)

    Dasch, E.J.

    1986-01-01

    Work completed on Apollo 14 basalts has been published. The two dates obtained from these rocks comprised the oldest and two of the three oldest ages (4.1 and 4.3 billion years) known for lunar maria basalts; thus their ages are important in understanding the moon's earliest history. Owing to the antiquity of these rocks, two more fragments have been dated as part of a second ASEE/NASA SFF program. The new ages are 3.95 and 4.12 billion years, thus further establishing and amplifying the earlier results. This work, although perhaps more interesting for its chronologic information, was begun as a test of chemical and petrographic models. Fragments of Apollo basalt were placed into five categories, based on petrologic and chemical, especially rare-earth element, composition. Isotopic studies were begun in an attempt to determine if the five groups of basalts were related by age or initial isotopic composition (isotopic composition of lava at time of extrusion). Although a few of the representatives of the five groups have the same age and/or initial strontium-isotopic composition, within the analtytical uncertainties, most apparently are unrelated. Petrologic implications of these data will be published in an appropriate journal

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-15

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

  16. Disruption of tephra fall deposits caused by lava flows during basaltic eruptions

    Science.gov (United States)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2015-10-01

    Observations in the USA, Iceland and Tenerife, Canary Islands reveal how processes occurring during basaltic eruptions can result in complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents. Observations illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter sheet-form fall deposits. Complexity arises through synchronous and alternating effusive and explosive activity that results in intercalated lavas and tephra deposits. Tephra deposits can become disrupted into mounds and ridges by lateral and vertical displacement caused by movement (including inflation) of underlying pāhoehoe lavas and clastogenic lavas. Mounds of tephra can be rafted away over distances of 100 s to 1,000 s m from proximal pyroclastic constructs on top of lava flows. Draping of irregular topography by fall deposits and subsequent partial burial of topographic depressions by later lavas can result in apparent complexity of tephra layers. These processes, deduced from field relationships, have resulted in considerable stratigraphic complexity in the studied proximal regions where fallout was synchronous or alternated with inflation of subjacent lava sheets. These mechanisms may lead to diachronous contact relationships between fall deposits and lava flows. Such complexities may remain cryptic due to textural and geochemical quasi-homogeneity within sequences of interbedded basaltic fall deposits and lavas. The net effect of these processes may be to reduce the usefulness of data collected from proximal fall deposits for reconstructing basaltic eruption dynamics.

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

    Digital Repository Service at National Institute of Oceanography (India)

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

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

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

    Science.gov (United States)

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

    2017-06-01

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

  19. 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.

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

    Indian Academy of Sciences (India)

    It lies midway between Kom Umbo city. (Nile Valley) and Abu Ghosoun port (Red Sea coast). Several authors dealt with remote sensing,. Keywords. FieldSpec data; olivine basalts; ASTER data; band ratios; brovey–HSV techniques. J. Earth Syst. Sci. 124, No. 7, October 2015, pp. 1475–1486 c Indian Academy of Sciences.

  1. Microstructure and mechanical properties of heat resistant composites reinforced with basalt fibres

    Czech Academy of Sciences Publication Activity Database

    Glogar, Petr; Sucharda, Zbyněk; Černý, Martin; Puchegger, S.; Peterlik, H.

    2007-01-01

    Roč. 51, č. 4 (2007), s. 190-197 ISSN 0862-5468 R&D Projects: GA ČR GA106/05/0817 Institutional research plan: CEZ:AV0Z30460519 Keywords : ceramic matrix composites * thermosetting resin * basalt fibre Subject RIV: JI - Composite Materials Impact factor: 0.488, year: 2007

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 109; Issue 1. Sr Isotopic Evidence on the Spilitic Degradation ... 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 ...

  3. Iridium content of basaltic tuffs and enclosing black shales of the balder formation, North Sea

    Science.gov (United States)

    Crawford Elliott, W.; Aronson, James L.; Millard, Hugh T., Jr.

    1992-07-01

    The anomalous levels of Ir and the presence of shocked metamorphosed quartz deposited at the Cretaceous/Tertiary (K/T) boundary worldwide is strong evidence that a meteorite impact took place during the K/T boundary interval. However, because of observed high Ir contents at Kilauea vents, it is still a major point of contention that the Ir anomaly could have been produced by flood basaltic volcanism. This might especially be true at Stevns Klint, Denmark, where the K/T boundary marl contains pyroclastic labradorite and Mg-smectite thought to have been produced by basaltic volcanism. However, up to now, no study has determined whether or not a depositional Ir anomaly has formed in association with a known major basaltic eruption. Herein, we report the concentrations of Ir, Pt, Au, and Ag in basaltic tuffs and enclosing marine black shales of the widespread Paleocene-Eocene Balder Formation. The tuffs in the Balder Formation represent explosive basaltic volcanism associated with the major volcano/tectonic activity of the opening of the northern North Atlantic Ocean. As such, they are the kind of eruption that could have possibly created a global K/T boundary-type Ir anomaly. Our results show that the tuffs and the shales on a per-weight basis both contain concentrations of Ir (0.1-0.25 ppb) that are higher than the Ir levels recently measured from terrestrial rocks including the Deccan Trap and Columbia River flood basalts, but are comparable to Hawaiian and Reunion Island basalts. Because of its thickness, the absolute amount of Ir expelled during the eruption of the main tuff sequence of the Balder Tuff is sizable. Yet for such an eruption to have produced a global Ir anomaly would mandate it having been one of an extremely high volatile content and it would have to have been erupted over a very short interval of time. Furthermore, such a high proportion of the volatilized Ir would have to have been injected into the stratosphere so that only small enrichments of

  4. 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

  5. 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

  6. 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

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

    Science.gov (United States)

    Harvey, Ralph P.; McKay, Gordon A.

    1997-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

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

    International Nuclear Information System (INIS)

    Dalmora, Adilson C.; Ramos, Claudete G.; Oliveira, Marcos L.S.; Teixeira, Elba C.; Kautzmann, Rubens M.; Taffarel, Silvio R.; Brum, Irineu A.S. de

    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 2 , Al 2 O 3 , and Fe 2 O 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-particle mineralogy and chemical

  10. 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

  11. Textural history of recent basaltic-andesites and plutonic inclusions from Merapi volcano

    Science.gov (United States)

    van der Zwan, Froukje M.; Chadwick, Jane P.; Troll, Valentin R.

    2013-07-01

    Mt. Merapi in Central Java is one of the most active stratovolcanoes on Earth and is underlain by a multistage plumbing system. Crystal size distribution analyses (CSD) were carried out on recent Merapi basaltic-andesites and co-eruptive magmatic and plutonic inclusions to characterise the crystallisation processes that operate during storage and ascent and to obtain information on respective time scales. The basaltic-andesites exhibit log-linear, kinked-upwards CSD curves for plagioclase and clinopyroxene that can be separated into two main textural populations. Large plagioclase phenocrysts (≥1.6 mm) make up one population, but correspond to crystals with variable geochemical composition and reflect a period of crystal growth at deep to mid-crustal levels. This population was subsequently influenced by crystal accumulation and the onset of crustal assimilation, including the incorporation of high-Ca skarn-derived xenocrysts. Textural re-equilibration is required for these crystals to form a single population in CSD. A second episode of crystal growth at shallower levels is represented by chemically homogenous plagioclase crystals <1.6 mm in size. Crustal assimilation is indicated by, for example, oxygen isotopes and based on the CSD data, crystallisation combined with contamination is likely semi-continuous in these upper crustal storage chambers. The CSD data observed in the basaltic-andesite samples are remarkably consistent and require a large-volume steady state magmatic system beneath Merapi in which late textural equilibration plays a significant role. Plagioclase CSDs of co-eruptive magmatic and plutonic inclusions may contain a third crystal population (<1 mm) not found in the lavas. This third population has probably formed from enhanced degassing of portions of basaltic-andesite magma at shallow crustal levels which resulted in increased crystallinity and basaltic-andesite mush inclusions. A suite of coarse plutonic inclusions is also present that

  12. Gas cluster ion beam for the characterization of organic materials in submarine basalts as Mars analogs

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Naoko, E-mail: naoko.sano@ncl.ac.uk; Barlow, Anders J.; Cumpson, Peter J. [National EPSRC XPS Users' Service (NEXUS), School of Mechanical and Systems Engineering, Stephenson Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom); Purvis, Graham W. H.; Abbott, Geoffrey D.; Gray, Neil N. D. [School of Civil Engineering and Geosciences, Devonshire Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom)

    2016-07-15

    The solar system contains large quantities of organic compounds that can form complex molecular structures. The processing of organic compounds by biological systems leads to molecules with distinctive structural characteristics; thus, the detection and characterization of organic materials could lead to a high degree of confidence in the existence of extra-terrestrial life. Given the nature of the surface of most planetary bodies in the solar system, evidence of life is more likely to be found in the subsurface where conditions are more hospitable. Basalt is a common rock throughout the solar system and the primary rock type on Mars and Earth. Basalt is therefore a rock type that subsurface life might exploit and as such a suitable material for the study of methods required to detect and analyze organic material in rock. Telluric basalts from Earth represent an analog for extra-terrestrial rocks where the indigenous organic matter could be analyzed for molecular biosignatures. This study focuses on organic matter in the basalt with the use of surface analysis techniques utilizing Ar gas cluster ion beams (GCIB); time of flight secondary ion mass spectrometry (ToF-SIMS), and x-ray photoelectron spectroscopy (XPS), to characterize organic molecules. Tetramethylammonium hydroxide (TMAH) thermochemolysis was also used to support the data obtained using the surface analysis techniques. The authors demonstrate that organic molecules were found to be heterogeneously distributed within rock textures. A positive correlation was observed to exist between the presence of microtubule textures in the basalt and the organic compounds detected. From the results herein, the authors propose that ToF-SIMS with an Ar GCIB is effective at detecting organic materials in such geological samples, and ToF-SIMS combined with XPS and TMAH thermochemolysis may be a useful approach in the study of extra-terrestrial organic material and life.

  13. Gas cluster ion beam for the characterization of organic materials in submarine basalts as Mars analogs

    International Nuclear Information System (INIS)

    Sano, Naoko; Barlow, Anders J.; Cumpson, Peter J.; Purvis, Graham W. H.; Abbott, Geoffrey D.; Gray, Neil N. D.

    2016-01-01

    The solar system contains large quantities of organic compounds that can form complex molecular structures. The processing of organic compounds by biological systems leads to molecules with distinctive structural characteristics; thus, the detection and characterization of organic materials could lead to a high degree of confidence in the existence of extra-terrestrial life. Given the nature of the surface of most planetary bodies in the solar system, evidence of life is more likely to be found in the subsurface where conditions are more hospitable. Basalt is a common rock throughout the solar system and the primary rock type on Mars and Earth. Basalt is therefore a rock type that subsurface life might exploit and as such a suitable material for the study of methods required to detect and analyze organic material in rock. Telluric basalts from Earth represent an analog for extra-terrestrial rocks where the indigenous organic matter could be analyzed for molecular biosignatures. This study focuses on organic matter in the basalt with the use of surface analysis techniques utilizing Ar gas cluster ion beams (GCIB); time of flight secondary ion mass spectrometry (ToF-SIMS), and x-ray photoelectron spectroscopy (XPS), to characterize organic molecules. Tetramethylammonium hydroxide (TMAH) thermochemolysis was also used to support the data obtained using the surface analysis techniques. The authors demonstrate that organic molecules were found to be heterogeneously distributed within rock textures. A positive correlation was observed to exist between the presence of microtubule textures in the basalt and the organic compounds detected. From the results herein, the authors propose that ToF-SIMS with an Ar GCIB is effective at detecting organic materials in such geological samples, and ToF-SIMS combined with XPS and TMAH thermochemolysis may be a useful approach in the study of extra-terrestrial organic material and life.

  14. Early Jurassic Carbon and Sodium Sequestration in a CAMP basalt flow

    Science.gov (United States)

    Block, K. A.; Puffer, J. H.

    2017-12-01

    The initial HTQ-type CAMP Orange Mountain Basalt flow, as well as related pillowed flows and the overlying Preakness flows, locally underwent substantial and well documented albitization, chloritization, and sulphate, carbonate, and zeolite mineralization. Layers representing at least 25 vol % of the Orange Mountain Basalt have undergone a major net increase in sodium and carbon content and a major redistribution of magnesium and calcium. Most alteration occurred during the development of a widespread early Jurassic geothermal system similar to the active system of Iceland. In both cases alteration was controlled by active circulation of basin brines through vesicular layers during rapid burial at temperatures that were kept elevated by recurring magmatism. Whole rock Na2O levels typically increased from 2.2 wt. % in unaltered layers to 3.2 wt. % in vesicular layers, and commonly reached levels exceeding 5 wt. %. The environmental implications of the removal of such massive amounts of sodium from the geothermal system on the chlorine budget and the salt content of Early Jurassic lakes are currently being evaluated. Massive amounts of carbon sequestration from the geothermal system may have mitigated an increased burden on the early Jurassic atmosphere where geothermal CO2 may have otherwise been vented at hot springs or solfataras. Calcite amygdules typically account for 5 to 10 vol. % of the vesiculated layers amounting to 66 to 132 kg of CO2 per m3 of basalt. If 25 vol. % of the 160 thick Orange Mountain Basalt is vesiculated that would equate to about 2640 to 5280 kg of CO2 per m2 of basalt. The full extent of calcite enrichment across the entire CAMP province, however, has not yet been determined.

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

    Science.gov (United States)

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

    2017-10-01

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

  16. 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.

  17. 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 Bahía 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.

  18. Continental Flood Basalts of Bennett Island, East Siberian Sea: High Arctic Geodynamics

    Science.gov (United States)

    Tegner, Christian; Pease, Victoria

    2014-05-01

    Volcanism provides a means of tracing mantle melting events and crustal evolution. The High Arctic includes a rich portfolio of volcanic rocks outcropping in the Circum-Arctic borderlands and imaged geophysically beneath the Alpha-Mendeleev Ridge that have been lumped together as a High-Arctic Large Igneous Province (HALIP). However, the ages (c. 440-60 Ma) and compositions (tholeiitic-alkaline-calc-alkaline) reported varies considerably and geological correlations remain elusive. One of the possible correlative events is the formation of continental flood basalts and sills in the Canadian Arctic Islands, Svalbard, Franz Josef Land and Bennett Island. These flood basalts have previously been linked to mantle plume melting and may represent a short-lived LIP event at c. 124-122 Ma. We present new data for a 350 m thick continental flood basalt succession at Bennett Island examined during fieldwork in Septemer 2013 on a joint Russian (VSEGEI) - Swedish (SWEDARCTIC) expedition to the De Long Archipelago. This volcanic succession is composed of 20 near-horisontal, undeformed flow units overlying a thin sedimentary succession of Cretaceous age (?) including coal seams and possibly volcaniclastic material that, in turn, unconformably overlies a more steeply dipping succession of Cambrian and Ordovician sediments. The flows are thinnest (c. 2-10 m) and aphyric to very-sparsely olivine-phyric in the lower portion. In contrast, the flows in the upper portion are thicker (>20 m) and aphyric to sparsely plagioclase-phyric. We will discuss new petrographic and compositional data for the Bennett Island flood basalts, possibly including new U-Pb age data. The aim is to evaluate their petrogenesis, to discuss their possible correlation to the flood basalt and sill successions of the Canadian Arctic Islands, Svalbard and Franz Josef Land and evaluate the geodynamic evolution of the High Arctic.

  19. Continental flood basalt weathering as a trigger for Neoproterozoic Snowball Earth

    Science.gov (United States)

    Cox, Grant M.; Halverson, Galen P.; Stevenson, Ross K.; Vokaty, Michelle; Poirier, André; Kunzmann, Marcus; Li, Zheng-Xiang; Denyszyn, Steven W.; Strauss, Justin V.; Macdonald, Francis A.

    2016-07-01

    Atmospheric CO2 levels and global climate are regulated on geological timescales by the silicate weathering feedback. However, this thermostat has failed multiple times in Earth's history, most spectacularly during the Cryogenian (c. 720-635 Ma) Snowball Earth episodes. The unique middle Neoproterozoic paleogeography of a rifting, low-latitude, supercontinent likely favored a globally cool climate due to the influence of the silicate weathering feedback and planetary albedo. Under these primed conditions, the emplacement and weathering of extensive continental flood basalt provinces may have provided the final trigger for runaway global glaciation. Weathering of continental flood basalts may have also contributed to the characteristically high carbon isotope ratios (δ13 C) of Neoproterozoic seawater due to their elevated P contents. In order to test these hypotheses, we have compiled new and previously published Neoproterozoic Nd isotope data from mudstones in northern Rodinia (North America, Australia, Svalbard, and South China) and Sr isotope data from carbonate rocks. The Nd isotope data are used to model the mafic detrital input into sedimentary basins in northern Rodinia. The results reveal a dominant contribution from continental flood basalt weathering during the ca. 130 m.y. preceding the onset of Cryogenian glaciation, followed by a precipitous decline afterwards. These data are mirrored by the Sr isotope record, which reflects the importance of chemical weathering of continental flood basalts on solute fluxes to the early-middle Neoproterozoic ocean, including a pulse of unradiogenic Sr input into the oceans just prior to the onset of Cyrogenian glaciation. Hence, our new data support the hypotheses that elevated rates of flood basalt weathering contributed to both the high average δ13 C of seawater in the Neoproterozoic and to the initiation of the first (Sturtian) Snowball Earth.

  20. Strontium isotopes as tracers to delineate aquifer interactions and the influence of rainfall in the basalt plains of southeastern Australia

    Science.gov (United States)

    Raiber, Matthias; Webb, John A.; Bennetts, Darren A.

    2009-04-01

    SummaryTo better understand the spatial distribution of groundwater salinisation in western Victoria, southeast Australia, the interactions between a surficial basalt aquifer and an underlying extensive palaeodrainage ('deep lead') system were studied using a multi-disciplinary approach, combining strontium isotope analyses with major ion chemistry and the interpretation of geological and hydrogeological data. The strontium isotopes proved particularly useful in delineating flow paths and hydraulic connections between the two aquifers, which have contrasting 87Sr/ 86Sr ratios. The freshest basalt groundwaters lie beneath volcanoes and have 87Sr/ 86Sr signatures close to the whole-rock strontium isotope ratios of the basalts (˜0.7045), indicating the strong influence of basalt weathering. With increasing distance from the eruption points, basalt groundwaters become progressively more saline and the strontium isotope ratios evolve towards the more radiogenic signatures of local rainfall (0.710-0.711), due to the slow addition of infiltration concentrated by evapotranspiration during its passage through the thick, clay-rich soils developed on the basalt lavas. Overall, the influence of rainwater on the strontium isotope signatures of the basalt groundwater is much greater than that of basaltic weathering, indicating that rainwater can play a greater role in determining groundwater strontium composition than is often realised. Most parts of the palaeodrainage system beneath the basalt are preferentially recharged through the volcanoes, as shown by strong downwards hydraulic gradients and groundwater 87Sr/ 86Sr ratios similar to the least radiogenic basalt groundwaters. However, in the northwestern part, groundwater 87Sr/ 86Sr ratios are closer to those of the source material of the sediments (Palaeozoic bedrock), indicating that here recharge occurs predominantly in the headwaters where the basalts are absent. In the southern and western sections of the palaeodrainage

  1. South Pole-Aitken Sample Return Mission: Collecting Mare Basalts from the Far Side of the Moon

    Science.gov (United States)

    Gillis, J. J.; Jolliff, B. L.; Lucey, P. G.

    2003-01-01

    We consider the probability that a sample mission to a site within the South Pole-Aitken Basin (SPA) would return basaltic material. A sample mission to the SPA would be the first opportunity to sample basalts from the far side of the Moon. The near side basalts are more abundant in terms of volume and area than their far-side counterparts (16:1), and the basalt deposits within SPA represent approx. 28% of the total basalt surface area on the far side. Sampling far-side basalts is of particular importance because as partial melts of the mantle, they could have derived from a mantle that is mineralogically and chemically different than determined for the nearside, as would be expected if the magma ocean solidified earlier on the far side. For example, evidence to support the existence of high-Th basalts like those that appear to be common on the nearside in the Procellarum KREEP Terrane has been found. Although SPA is the deepest basin on the Moon, it is not extensively filled with mare basalt, as might be expected if similar amounts of partial melting occurred in the mantle below SPA as for basins on the near side. These observations may mean that mantle beneath the far-side crust is lower in Th and other heat producing elements than the nearside. One proposed location for a sample-return landing site is 60 S, 160 W. This site was suggested to maximize the science return with respect to sampling crustal material and SPA impact melt, however, basaltic samples would undoubtedly occur there. On the basis of Apollo samples, we should expect that basaltic materials would be found in the vicinity of any landing site within SPA, even if located away from mare deposits. For example, the Apollo 16 mission landed in an ancient highlands region 250-300 km away from the nearest mare-highlands boundary yet it still contains a small component of basaltic samples (20 lithic fragments ranging is size from <1 to .01 cm). A soil sample from the floor of SPA will likely contain an

  2. Radiation shielding properties of high performance concrete reinforced with basalt fibers infused with natural and enriched boron

    Energy Technology Data Exchange (ETDEWEB)

    Zorla, Eyüp; Ipbüker, Cagatay [University of Tartu, Institute of Physics (Estonia); Biland, Alex [US Basalt Corp., Houston (United States); Kiisk, Madis [University of Tartu, Institute of Physics (Estonia); Kovaljov, Sergei [OÜ Basaltest, Tartu (Estonia); Tkaczyk, Alan H. [University of Tartu, Institute of Physics (Estonia); Gulik, Volodymyr, E-mail: volodymyr.gulik@gmail.com [Institute for Safety Problems of Nuclear Power Plants, Lysogirska 12, of. 201, 03028 Kyiv (Ukraine)

    2017-03-15

    Highlights: • Basalt fiber infused with natural and enriched boron in varying proportions. • Gamma-ray attenuation remains stable with addition of basalt-boron fiber. • Improvement in neutron shielding for nuclear facilities producing fast fission spectrum. • Basalt-boron fiber could decrease the shielding thickness in thermal spectrum reactors. - Abstract: The importance of radiation shielding is increasing in parallel with the expansion of the application areas of nuclear technologies. This study investigates the radiation shielding properties of two types of high strength concrete reinforced with basalt fibers infused with 12–20% boron oxide, containing varying fractions of natural and enriched boron. The gamma-ray shielding characteristics are analyzed with the help of the WinXCom, whereas the neutron shielding characteristics are modeled and computed by Monte Carlo Serpent code. For gamma-ray shielding, the attenuation coefficients of the studied samples do not display any significant variation due to the addition of basalt-boron fibers at any mixing proportion. For neutron shielding, the addition of basalt-boron fiber has negligible effects in the case of very fast neutrons (14 MeV), but it could considerably improve the neutron shielding of concrete for nuclear facilities producing a fast fission spectrum (e.g. with reactors as BN-800, FBTR) and thermal neutron spectrum (Light Water Reactors (LWR)). It was also found that basalt-boron fiber could decrease the thickness of radiation shielding material in thermal spectrum reactors.

  3. Basalt fibers: the green material of the XXI-century, for a sustainable restoration of historical buildings

    Directory of Open Access Journals (Sweden)

    Giacomo Di Ruocco

    2016-12-01

    Full Text Available In recent decades in the construction industry, the need to experience consolidation techniques with non-corroding materials is being developed. Studies and tests have been led about integration of basalt fibers in concrete structures: they have shown improvements both in terms of mechanical strength and in terms of intervention of consolidation durability (Ólafsson, Thorhallsson, 2009. The basalt rock can be used to produce not only basalt bars, but also fabrics, paddings, continuous filaments and basalt network. Some applications of these basalt-composites materials concern the consolidation of civil construction structures, thermal and acoustic insulation, security clothing, etc. Some years ago the Italian company ENEA (National Agency for New Technologies, Energy and Sustainable Economic Development has signed an agreement with HG GBF (one of the world's leading companies in the production of basalt fibers, for the verification of possible applications of this material in the construction field but also in the nautical and automotive ones. The use of basalt fiber in construction could present a series of advantages: natural origin, a cycle of production to lower energy impact compared to other fibers, a high chemical inertia and thus a high degree of durability, low thermal conductivity, good mechanical and thermo-acoustic properties, high fire resistance, a competitive cost and, in general, more environmental compatibility and sustainability than other synthetic fibers.

  4. Mapping and compositional analysis of mare basalts in the Aristarchus region of the Moon using Clementine data

    International Nuclear Information System (INIS)

    Zhang Feng; Zou Yong-Liao; Zheng Yong-Chun; Fu Xiao-Hui; Zhu Yong-Chao

    2014-01-01

    The process of accurately defining and outlining mare basalt units is necessary for constraining the stratigraphy and ages of basalt units, which are used to determine the duration and the flux of lunar volcanism. We use a combination of Clementine's five-band ultraviolet/visible data and TiO 2 and FeO abundance distribution maps to define homogenous mare basalt units and characterize their compositional variations (with maturity) in the Aristarchus region. With 20 groups of distinct mare basaltic soils identified using the method in this paper, six additional spectrally defined areas and five basaltic units are constructed, and their mineralogic quantization values provide new constraints on their temporal and spatial evolution. Our results indicate that the Aristarchus region has diverse basalt units and a complex history of volcanic evolution. We also demonstrate that the techniques, from which spectrally distinct mare basalts can be mapped, performed well in this study and can be confidently expanded to other mare regions of the Moon. (research papers)

  5. Basalt Reactivity Variability with Reservoir Depth in Supercritical CO2 and Aqueous Phases

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Herbert T.; McGrail, B. Peter; Owen, Antionette T.

    2011-04-01

    Long term storage of CO{sub 2} in geologic formations is currently considered the most attractive option to reduce greenhouse gas emissions while continuing to utilize fossil fuels for energy production. Injected CO{sub 2} is expected to reside as a buoyant water-saturated supercritical fluid in contact with reservoir rock, the caprock system, and related formation waters. As was reported for the first time at the GHGT-9 conference, experiments with basalts demonstrated surprisingly rapid carbonate mineral formation occurring with samples suspended in the scCO{sub 2} phase. Those experiments were limited to a few temperatures and CO{sub 2} pressures representing relatively shallow (1 km) reservoir depths. Because continental flood basalts can extend to depths of 5 km or more, in this paper we extend the earlier results across a pressure-temperature range representative of these greater depths. Different basalt samples, including well cuttings from the borehole used in a pilot-scale basalt sequestration project (Eastern Washington, U.S.) and core samples from the Central Atlantic Magmatic Province (CAMP), were exposed to aqueous solutions in equilibrium with scCO{sub 2} and water-rich scCO{sub 2} at six different pressures and temperatures for select periods of time (30 to 180 days). Conditions corresponding to a shallow injection of CO{sub 2} (7.4 MPa, 34 C) indicate limited reactivity with basalt; surface carbonate precipitates were not easily identified on post-reacted basalt grains. Basalts exposed under identical times appeared increasingly more reacted with simulated depths. Tests, conducted at higher pressures (12.0 MPa) and temperatures (55 C), reveal a wide variety of surface precipitates forming in both fluid phases. Under shallow conditions tiny clusters of aragonite needles began forming in the wet scCO{sub 2} fluid, whereas in the CO{sub 2} saturated water, cation substituted calcite developed thin radiating coatings. Although these types of coatings

  6. Preliminary geochemical and physical testing of materials for plugging of man-made accesses to a repository in basalt

    International Nuclear Information System (INIS)

    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

  7. Solid phases limiting the concentration of dissolved constituents in basalt aquifers of the Columbia Plateau in eastern Washington

    International Nuclear Information System (INIS)

    Deutsch, W.J.; Jenne, E.A.; Krupka, K.M.

    1981-01-01

    The purposes of this study were: (1) to provide information on the solid phases which are in apparent equilibrium with ground waters of basalt aquifers, and (2) to further develop the capability of geochemical modeling to support solute transport studies and performance assessments of nuclear waste repositories. The basalt aquifers of the Columbia Plateau in eastern Washington were chosen as the study area because: (1) regional ground-water analyses are readily available, (2) these basalts are a potential medium for a nuclear-waste repository, and (3) mineralogical analyses from local site studies are available

  8. New potassium-argon basalt data in relation to the Pliocene Bluff Downs Local Fauna, northern Australia

    International Nuclear Information System (INIS)

    Mackness, B.S.

    2000-01-01

    A new radiometric date of 3.6 Ma for the basalt overlying fossiliferous units of the Allingham Formation, provides a minimum age for the Bluff Downs Local Fauna. Ground studies and interpretation of aerial photography has clarified the volcanic history of the area and a new basalt flow has been identified and named. Although the age of the capping basalt permits a younger age for the Bluff Downs Local Fauna than originally described, the stratigraphy, combined with the interpreted stage of evolution of the fauna, still supports an Early Pliocene age for the site. Copyright (2000) Geological Society of Australia

  9. 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

  10. Investigating the Influence of Waste Basalt Powder on Selected Properties of Cement Paste and Mortar

    Science.gov (United States)

    Dobiszewska, Magdalena; Beycioğlu, Ahmet

    2017-10-01

    Concrete is the most widely used man-made construction material in civil engineering applications. The consumption of cement and thus concrete, increases day by day along with the growth of urbanization and industrialization and due to new developments in construction technologies, population growing, increasing of living standard. Concrete production consumes much energy and large amounts of natural resources. It causes environmental, energy and economic losses. The most important material in concrete production is cement. Cement industry contributes to production of about 7% of all CO2 generated in the world. Every ton of cement production releases nearly one ton of CO2 to atmosphere. Thus the concrete and cement industry changes the environment appearance and influences it very much. Therefore, it has become very important for construction industry to focus on minimizing the environmental impact, reducing energy consumption and limiting CO2 emission. The need to meet these challenges has spurred an interest in the development of a blended Portland cement in which the amount of clinker is reduced and partially replaced with mineral additives - supplementary cementitious materials (SCMs). Many researchers have studied the possibility of using another mineral powder in mortar and concrete production. The addition of marble dust, basalt powder, granite or limestone powder positively affects some properties of cement mortar and concrete. This paper presents an experimental study on the properties of cement paste and mortar containing basalt powder. The basalt powder is a waste emerged from the preparation of aggregate used in asphalt mixture production. Previous studies have shown that analysed waste used as a fine aggregate replacement, has a beneficial effect on some properties of mortar and concrete, i.e. compressive strength, flexural strength and freeze resistance also. The present study shows the results of the research concerning the modification of cement

  11. Geochemical constraints on the spatial distribution of recycled oceanic crust in the mantle source of late Cenozoic basalts, Vietnam

    Science.gov (United States)

    Hoang, Thi Hong Anh; Choi, Sung Hi; Yu, Yongjae; Pham, Trung Hieu; Nguyen, Kim Hoang; Ryu, Jong-Sik

    2018-01-01

    This study presents a comprehensive analysis of the major and trace element, mineral, and Sr, Nd, Pb and Mg isotopic compositions of late Cenozoic intraplate basaltic rocks from central and southern Vietnam. The Sr, Nd, and Pb isotopic compositions of these basalts define a tight linear array between Indian mid-ocean-ridge basalt (MORB)-like mantle and enriched mantle type 2 (EM2) components. These basaltic rocks contain low concentrations of CaO (6.4-9.7 wt%) and have high Fe/Mn ratios (> 60) and FeO/CaO-3MgO/SiO2 values (> 0.54), similar to partial melts derived from pyroxenite/eclogite sources. This similarity is also supported by the composition of olivine within these samples, which contains low concentration of Ca and high concentrations of Ni, and shows high Fe/Mn ratios. The basaltic rocks have elevated Dy/Yb ratios that fall within the range of melts derived from garnet lherzolite material, although their Yb contents are much higher than those of modeled melts derived from only garnet lherzolite material and instead plot near the modeled composition of eclogite-derived melts. The Vietnamese basaltic rocks have lighter δ26Mg values (- 0.38 ± 0.06‰) than is expected for the normal mantle (- 0.25 ± 0.07‰), and these values decrease with decreasing Hf/Hf* and Ti/Ti* ratios, indicating that these basalts were derived from a source containing carbonate material. On primitive mantle-normalized multi-element variation diagrams, the central Vietnamese basalts are characterized by positive Sr, Eu, and Ba anomalies. These basalts also plot within the pelagic sediment field in Pbsbnd Pb isotopic space. This suggests that the mantle source of the basalts contained both garnet peridotite and recycled oceanic crust. A systematic analysis of variations in geochemical composition in basalts from southern to central Vietnam indicates that the recycled oceanic crust (possibly the paleo-Pacific slab) source material contains varying proportions of gabbro, basalt, and

  12. Maar-diatreme volcanism relating to the pyroclastic sequence of a newly discovered high-alumina basalt in the Maroa Volcanic Centre, Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Kósik, S.; Németh, K.; Procter, J. N.; Zellmer, G. F.

    2017-07-01

    Diatreme sequences have previously been described from drill holes within the Taupo Volcanic Zone. The newly discovered Te Hukui Basalt exhibits deep excavation of country rocks that do not appear elsewhere at the surface. The basalt is characterized by proximal deposition of pyroclastic deposits relating to phreatomagmatism. The geochemical composition classifies these rocks as high-alumina basalts. They erupted along the Orakeikorako Fault at the same location where rhyolitic activity of Puketerata occurred at a later point in time. The petrological characteristics of the basalts indicate the mixing of mafic melt with crystalline mush relating to more evolved magmas. The new basaltic occurrence supports frequent mafic recharge of shallow magma reservoirs, inducing basaltic eruptions, in this case the mafic magma intruding into highly crystallized mush zones. This may explain why basaltic eruptions mostly occur on the edge of the central extensional part of the Taupo Volcanic Zone.

  13. U-Pb zircon geochronology and geochemistry of Late Jurassic basalts in Maevatanana, Madagascar: Implications for the timing of separation of Madagascar from Africa

    Science.gov (United States)

    Yang, Xi-An; Chen, Yu-Chuan; Hou, Ke-Jun; Liu, Shan-Bao; Liu, Jia-Jun

    2014-12-01

    Magmatic zircon ages for the Maevatanana basalts in Madagascar indicate that Madagascar separated from Africa at 149.8 ± 2.1 Ma. Rocks produced by this basaltic magmatism associated with rifting are characterized by low SiO2 (49.6-50.3 wt.%), high total FeO (>13.9 wt.%), TiO2 (>3.7 wt.%), and P2O5 (>0.5 wt.%), and extremely high Na2O/K2O (3.08-3.27). Geochemical variations can be ascribed to significant fractional crystallization of clinopyroxene and plagioclase. The mineralogical and geochemical characteristics of the Maevatanana basalts suggest affinities with calc-alkaline basalt. Additionally the basalts have distinct ocean-island-basalt-like geochemical features that may be related to the Marion plume. We speculate that the Maevatanana basalts are the product of the Marion mantle plume related to separation of Madagascar from Africa in the Late Jurassic.

  14. 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.

  15. 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.

  16. Intermediate-scale sodium-concrete reaction tests with basalt and limestone concrete

    International Nuclear Information System (INIS)

    Hassberger, J.A.; Muhlestein, L.D.

    1981-01-01

    Ten tests were performed to investigate the chemical reactions and rate and extent of attack between sodium and basalt and limestone concretes. Test temperatures ranged from 510 to 870 0 C (950 to 1600 0 F) and test times from 2 to 24 hours. Sodium hydroxide was added to some of the tests to assess the impact of a sodium hydroxide-aided reaction on the overall penetration characteristics. Data suggest that the sodium penetration of concrete surfaces is limited. Penetration of basalt concrete in the presence of sodium hydroxide is shown to be less severe than attack by the metallic sodium alone. Presence of sodium hydroxide changes the characteristics of sodium penetration of limestone concrete, but no major differences in bulk penetration were observed as compared to penetration by metallic sodium

  17. 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.

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

    Science.gov (United States)

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

    2010-09-01

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

  19. 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.

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

    DEFF Research Database (Denmark)

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

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

  1. Bulk Chemical Fractionation Between Basalt, Impact-Melts and Spherules of Lonar Impact Crater, India

    Science.gov (United States)

    Misra, S.; Prasad, M.; Saha, D.; Sengupta, D.; Khedekar, V. D.; Dube, A.; Newsom, H. E.

    2005-12-01

    The ~50,000 year old Lonar Crater, India, is one of the two known continental impact craters that were excavated on basalt. In-situ impact-melts from within ejecta from the SE crater rim are associated with splash form impact-spherules of two types: mm-size non-magnetic spherules, also found in other parts of the ejecta, and slightly smaller magnetic spherules with smoother surfaces. Both impact-melts and the two types of spherules have homogeneous compositions, though minor systematic variations exist in impact melts. Compared to unaltered target basalt, average impact-melt characteristically shows ~21-22% depletion in Na2O and ~44-61% enrichment in K2O, while impact-spherules show more depletion in Na2O (~41-42%) and less enrichment in K2O (~21-29%). Additionally average magnetic spherules are enriched in MgO (~22%) and depleted in CaO (~9%) and Fe2O3}T (~7%), while non-magnetic spherules are depleted in MgO (~11%) and enriched in CaO (~13%) and Fe2O3T (~2%) over target-basalt. #Mg for impact-melts and non-magnetic spherules have restricted and overlapping values between ~0.35 and 0.43, but for magnetic spherules it varies between 0.38 and 0.56. The small variation in mobile CaO (~3.4 wt%), Na2O (~2.4 wt%) and K2O (~0.8 wt%) of target-rock and impactites suggest limited weathering of the samples. Lonar impactites were formed by plagioclase- dominated partial melting of target-basalt, which caused enrichment of K2O in impactites and Rb, Cs, Ba, La, Ce, Nd and Th in impact-melts and non-magnetic spherules, while another important target- rock constituent, augite, was variably mixed with plagioclase-melt only in the highest stage of shock metamorphism. Depletion of Na2O in impactites occurred due to limited separation of xenocrystic augite (Na2O ~0.23 and 0.26 wt%) from these molten impactites. Mixing models suggest proportions of plagioclase melt and augite in average impact-melts and non-magnetic spherules is close to ~1:0.4, in magnetic spherules it varies

  2. Ascent and eruption of basaltic magma on the earth and moon

    International Nuclear Information System (INIS)

    Wilson, L.; Head, J.W. III.

    1981-01-01

    Geological and physical observations and constraints are applied to the development of a model of the ascent and emplacement of basaltic magma on the earth and moon. Mathematical models of the nature and motion of gas/liquid mixtures are developed and show that gas exsolution from terrestrial and lunar magmas commonly only occurs at shallow depths (less than 2 km); thus the ascent of bubble-free magma at depth can be treated separately from the complex motions caused by gas exsolution near the surface. Magma ascent is related to dike or conduit width. For terestrial basalts with negligible yield strengths and viscosities greater than 10 2 Ps s, widths in the range 0.2--0.6 m are needed to allow eruptions from between depths of 0.5--20 km. Fissure widths of about 4 m would be needed to account for output rates estimated for the Columbia River flood basalt eruptions. As the magma nears the surface, bubble coalescence will tend to occur, leading to intermittent explosive strombolian-style activity. For commonly occuring lunar and terrestrial basalts the magma rise speed must be greater than 0.5-1 m/s if strombolian activity is to be avoided and relatively steady fire fountaining is to take place. Terrestrial fire fountain heights are dictated by the vertical velocity of the magma/gas dispersion emerging through the vent, increasing with increasing magma gas content and mass eruption rate, and decreasing with increasing magma viscosity. Terrestrial fire fountain heights up to 500 m imply the release of up to 0.4 wt % water from the magma, corresponding to initial water contents up to 0.6 wt %. The presence of extremely long lava flows and sinuous rilles on the moon has often been cited as evidence for very high extrusion rates and thus a basic difference between terrestrial and lunar magmas and crustal environments

  3. Evolution of porosity and diffusivity associated with chemical weathering of a basalt clast

    Energy Technology Data Exchange (ETDEWEB)

    Navarre-Sitchler, A.; Steefel, C.I.; Yang, L.; Tomutsa, L.; Brantley, S.L.

    2009-02-15

    Weathering of rocks as a result of exposure to water and the atmosphere can cause significant changes in their chemistry and porosity. In low-porosity rocks, such as basalts, changes in porosity, resulting from chemical weathering, are likely to modify the rock's effective diffusivity and permeability, affecting the rate of solute transport and thus potentially the rate of overall weathering to the extent that transport is the rate limiting step. Changes in total porosity as a result of mineral dissolution and precipitation have typically been used to calculate effective diffusion coefficients through Archie's law for reactive transport simulations of chemical weathering, but this approach fails to account for unconnected porosity that does not contribute to transport. In this study, we combine synchrotron X-ray microcomputed tomography ({mu}CT) and laboratory and numerical diffusion experiments to examine changes in both total and effective porosity and effective diffusion coefficients across a weathering interface in a weathered basalt clast from Costa Rica. The {mu}CT data indicate that below a critical value of {approx}9%, the porosity is largely unconnected in the basalt clast. The {mu}CT data were further used to construct a numerical pore network model to determine upscaled, effective diffusivities as a function of total porosity (ranging from 3 to 30%) for comparison with diffusivities determined in laboratory tracer experiments. By using effective porosity as the scaling parameter and accounting for critical porosity, a model is developed that accurately predicts continuum-scale effective diffusivities across the weathering interface of the basalt clast.

  4. 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

    2017-05-01

    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.

  5. Mantle source heterogeneity of the Early Jurassic basalt of eastern North America

    Science.gov (United States)

    Gregory Shellnutt, J.; Dostal, Jaroslav; Yeh, Meng-Wan

    2018-04-01

    One of the defining characteristics of the basaltic rocks from the Early Jurassic Eastern North America (ENA) sub-province of the Central Atlantic Magmatic Province (CAMP) is the systematic compositional variation from South to North. Moreover, the tectono-thermal regime of the CAMP is debated as it demonstrates geological and structural characteristics (size, radial dyke pattern) that are commonly associated with mantle plume-derived mafic continental large igneous provinces but is considered to be unrelated to a plume. Mantle potential temperature ( T P) estimates of the northern-most CAMP flood basalts (North Mountain basalt, Fundy Basin) indicate that they were likely produced under a thermal regime ( T P ≈ 1450 °C) that is closer to ambient mantle ( T P ≈ 1400 °C) conditions and are indistinguishable from other regions of the ENA sub-province ( T Psouth = 1320-1490 °C, T Pnorth = 1390-1480 °C). The regional mantle potential temperatures are consistent along the 3000-km-long ENA sub-province suggesting that the CAMP was unlikely to be generated by a mantle plume. Furthermore, the mantle potential temperature calculation using the rocks from the Northern Appalachians favors an Fe-rich mantle (FeOt = 8.6 wt %) source, whereas the rocks from the South Appalachians favor a less Fe-rich (FeOt = 8.3 wt %) source. The results indicate that the spatial-compositional variation of the ENA basaltic rocks is likely related to differing amounts of melting of mantle sources that reflect the uniqueness of their regional accreted terranes (Carolinia and West Avalonia) and their post-accretion, pre-rift structural histories.

  6. Geology of hole drill thermal infra basaltic (Guarani Aquifer System) in Salto Uruguay

    International Nuclear Information System (INIS)

    Goso, C.; Muzio, R.; Marmisolle, J.; De Souza, S.

    2004-01-01

    This paper deals with the lithological description of a thermal infrabasaltic (Guarani Aquifer System) hole drill cutting in Dayman (Kanarek Hotel), Salto department (Uruguay). This hole drill shows 152 meters of Buena Vista Formation (Upper Permian- Lower Triassic), 188 meters of Tacuarembo Formation (Upper Jurassic-Lower Cretaceous) and 940meters of Arapey Formation (Lower Cretaceous). Petrographical studies of six basaltic levels were done [es

  7. Petrology of rift-related basalts at Bombay High waters, Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

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

    Tholeiitic basalts obtained in 6 cores from Bombay High Region (Maharashtra, India), at depths of 860-2550 m below the seabed, are of low K and high Fe types. SiO sub(2) varies from 45.68 to 50.72%, K sub(2)O 0.09 to 0.69%, TiO sub(2) 1.06 to 2...

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

  9. 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.

  10. 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.

  11. Basaltic rocks behavior of the Corrientes and Entre Rios province from the alcali silice reaction

    International Nuclear Information System (INIS)

    Marfil, S.; Batic, O.; Grecco, L.; Falcone, D.

    2010-01-01

    This work is about the basaltic rocks deposits in Mesopotamia - Argentina. This material is used for dikes, flooring and art . In several of them has been developed expansive processes associated with alkali - silica reaction such as pavements of some routes. In order to evaluate the behavior of these rocks their are obtained samples from the quarries using standard methods such as petrographic, rod accelerated and dissolved silica agree with the IRA M standards

  12. The solubility of sulfur in high-TiO2 mare basalts

    Science.gov (United States)

    Danckwerth, P. A.; Hess, P. C.; Rutherford, M. J.

    1979-01-01

    The present paper deals with an experimental investigation of the solubility of sulfur of the high-TiO2 mare basalt 74275 at 1 atm, 1250 C. The data indicate that at saturation, 74275 is capable of dissolving 3400 ppm sulfur at 10 to 15 degrees below its liquidus. The analyzed samples of 74275 show sulfur contents of 1650 ppm S, which indicates that 74275 was 50% undersaturated at the time of eruption.

  13. Petrographical indicators of petrogenesis: Examples from Central Indian Ocean Basin basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Iyer, S.D.

    petrographic entities that can help to establish a range of under- coolings. The distinction may simply be differences in the length of acicular plagioclase needles in flow interiors 7 and spacing between plagioclase dendrites at known distances from... carried out to help identify the various morpho-tectonic features of the basin. Besides the nodules and encrustations, a number of volcanics were also retrieved. Most of the volcanics are basalts obtained from a depth of 5000 m between lat. 10 o -15 o...

  14. Development of Braided Basalt FRP Rebar for Reinforcement of Concrete Structures

    OpenAIRE

    Antonopoulou, Sofia; McNally, Ciaran; Byrne, Greg

    2016-01-01

    In recent years, the development and use of Fibre Reinforced Polymer composite materials in infrastructure have gained increasing attention worldwide. More specifically, natural mineral fibres such as basalt are currently being developed and are showing promising properties. Within an appropriate polymer matrix, their use as reinforcement in concrete structures offers performance benefits related to their environmentally friendly and non-corrodible nature. In particular, BFRPs have the potent...

  15. Geochemistry and petrology of pyroxenite xenoliths from Cenozoic alkaline basalts, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Ackerman, Lukáš; Špaček, Petr; Medaris Jr., G.; Hegner, E.; Svojtka, Martin; Ulrych, Jaromír

    2012-01-01

    Roč. 57, č. 4 (2012), s. 199-219 ISSN 1802-6222 R&D Projects: GA ČR(CZ) GA205/09/1170 Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z30120515 Institutional support: RVO:67985831 ; RVO:67985530 Keywords : pyroxenite * xenolith * Cenozoic * basalt * Sr-Nd isotopes * geothermobarometry Subject RIV: DD - Geochemistry Impact factor: 0.804, year: 2012

  16. Petrologic insights into basaltic volcanism at historically active Hawaiian volcanoes: Chapter 6 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Helz, Rosalind L.; Clague, David A.; Sisson, Thomas W.; Thornber, Carl R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Study of the petrology of Hawaiian volcanoes, in particular the historically active volcanoes on the Island of Hawai‘i, has long been of worldwide scientific interest. When Dr. Thomas A. Jaggar, Jr., established the Hawaiian Volcano Observatory (HVO) in 1912, detailed observations on basaltic activity at Kīlauea and Mauna Loa volcanoes increased dramatically. The period from 1912 to 1958 saw a gradual increase in the collection and analysis of samples from the historical eruptions of Kīlauea and Mauna Loa and development of the concepts needed to evaluate them. In a classic 1955 paper, Howard Powers introduced the concepts of magnesia variation diagrams, to display basaltic compositions, and olivine-control lines, to distinguish between possibly comagmatic and clearly distinct basaltic lineages. In particular, he and others recognized that Kīlauea and Mauna Loa basalts must have different sources.

  17. Supplemental technical information in support of Y/OWI/TM--44. Volume 15. Drawings for repository preconceptual design studies: basalt

    International Nuclear Information System (INIS)

    1978-04-01

    Volume 15 contains the drawings of a preconceptual design for a nuclear waste repository in basalt. Three fuel cycles are considered: fuel recycle, throwaway cycle, and uranium recycle with plutonium in the high-level wastes

  18. The human impact on natural rock reserves using basalt, anorthosite, and carbonates as raw materials in insulation products

    DEFF Research Database (Denmark)

    Dahl, Tais Wittchen; Clausen, Anders U.; Hansen, Peter B.

    2011-01-01

    , and carbonates are widespread on all continents. Although basaltic rocks cover most of the ocean floor, these reserves are hidden below several kilometres of water and therefore are regarded as inaccessible. Instead, large igneous provinces on land constitute major basaltic reserves useful for human rock...... of these rock types are so large that they could supply current human demand for millions of years. The natural degradation of surface rocks occurs by physical and chemical weathering creating sediment that is transported along rivers and deposited in the ocean. Sediments are either obducted with continental......% basalt, 20 wt% anorthosite, and 40 wt% cement-bonded renewable materials. This study provides an overview of the natural cycle of these resources, including their abundances in nature, and sets the consumption by the stone wool industry and other human activities in perspective. Basalt, anorthosite...

  19. Continental basalts record the crust-mantle interaction in oceanic subduction channel: A geochemical case study from eastern China

    Science.gov (United States)

    Xu, Zheng; Zheng, Yong-Fei

    2017-09-01

    Continental basalts, erupted in either flood or rift mode, usually show oceanic island basalts (OIB)-like geochemical compositions. Although their depletion in Sr-Nd isotope compositions is normally ascribed to contributions from the asthenospheric mantle, their enrichment in large ion lithophile elements (LILE) and light rare earth elements (LREE) is generally associated with variable enrichments in the Sr-Nd isotope compositions. This indicates significant contributions from crustal components such as igneous oceanic crust, lower continental crust and seafloor sediment. Nevertheless, these crustal components were not incorporated into the mantle sources of continental basalts in the form of solidus rocks. Instead they were processed into metasomatic agents through low-degree partial melting in order to have the geochemical fractionation of the largest extent to achieve the enrichment of LILE and LREE in the metasomatic agents. Therefore, the mantle sources of continental basalts were generated by metasomatic reaction of the depleted mid-ocean ridge basalts (MORB) mantle with hydrous felsic melts. Nevertheless, mass balance considerations indicate differential contributions from the mantle and crustal components to the basalts. While the depleted MORB mantle predominates the budget of major elements, the crustal components predominate the budget of melt-mobile incompatible trace elements and their pertinent radiogenic isotopes. These considerations are verified by model calculations that are composed of four steps in an ancient oceanic subduction channel: (1) dehydration of the subducting crustal rocks at subarc depths, (2) anataxis of the dehydrated rocks at postarc depths, (3) metasomatic reaction of the depleted MORB mantle peridotite with the felsic melts to generate ultramafic metasomatites in the lower part of the mantle wedge, and (4) partial melting of the metasomatites for basaltic magmatism. The composition of metasomatites is quantitatively dictated by

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-03-24

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

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

    International Nuclear Information System (INIS)

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

    1982-09-01

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

  2. Epithermal neutron activation analysis of CR(VI)-reducer basalt-inhabiting bacteria

    International Nuclear Information System (INIS)

    Tsibakhashvili, N.Ya.; Kalabegishvili, T.L.; Murusidze, I.G.; Mosulishvili, L.M.; Frontas'eva, M.V.; Kirkesali, E.I.; Aksenova, N.G.; Holman, H.Y.

    2005-01-01

    Epithermal neutron activation analysis (ENAA) has been applied to studying elemental composition of Cr(VI)-reducer bacteria isolated from polluted basalts from the Republic of Georgia. Cr(VI)-reducing ability of the bacteria was examined by electron spin resonance (ESR) demonstrating that the bacteria differ in the rates of Cr(VI) reduction. A well-pronounced correlation between the ability of the bacteria to accumulate Cr(VI) and their ability to reduce Cr(V) to Cr(III) observed in our experiments is discussed. Elemental analysis of these bacteria also revealed that basalt-inhabiting bacteria are distinguished by relative contents of essential elements such as K, Na, Mg, Fe, Mn, Zn, and Co. A high rate of Cr(III) formation correlates with a high concentration of Co in the bacterium. ENAA detected some similarity in the elemental composition of the bacteria. The relatively high contents of Fe detected in the bacteria (140-340 μg/g of dry weight) indicate bacterial adaptation to the environmental conditions typical of the basalts. The concentrations of at least 12-19 different elements ranging from major- to ultratrace ones were determined in each type of bacteria simultaneously. The range of concentrations spans over 8 orders of magnitude

  3. New chemical determinations of zinc in basalts, and rocks of similar composition

    Science.gov (United States)

    Rader, L.F.; Swadley, W.C.; Huffman, C.; Lipp, H.H.

    1963-01-01

    New determinations of zinc in 124 basalts by the chemical method described (Huff-Man et al. 1963) are reported. Average zinc values, in per cent, for basalts from diverse regions are as follows: Idaho, 28 samples, 0.013; Hawaii, 33 samples, 0.010; Connecticut, 27 samples, 0.0090; Oregon, 17 samples, 0.0081; California, 8 samples, 0.0071; and New Mexico, 11 samples, 0.0086; average, all samples, 0.0099 per cent zinc. A plot of differentiation indicator ratios calculated from the conventional rock analyses, CaO/(Na2O + K2O) as the ordinate and SiO2/MgO as the abscissa, was used to select, from different localities, samples essentially the same in chemical composition that were to be used for comparisons of zinc and other minor elements. Zinc correlates with MnO and with total iron as FeO. An inverse relationship found for zinc and manganese is related to the total iron content of the basalts. Thus for a given iron concentration as zinc increases, manganese decreases and vice versa. Ratios of zinc, the common denominator, to 11 other minor elements determined spectro-graphically show correlations with cobalt, gallium, scandium, yttrium, and zirconium. ?? 1963.

  4. CO2 diffusion into pore spaces limits weathering rate of an experimental basalt landscape

    Science.gov (United States)

    van Haren, Joost; Dontsova, Katerina; Barron-Gafford, Greg A.; Troch, Peter A.; Chorover, Jon; DeLong, Stephen B.; Breshears, David D.; Huxman, Travis E.; Pelletier, Jon D.; Saleska, Scott; Zeng, Xubin; Ruiz, Joaquin

    2017-01-01

    Basalt weathering is a key control over the global carbon cycle, though in situ measurements of carbon cycling are lacking. In an experimental, vegetation-free hillslope containing 330 m3 of ground basalt scoria, we measured real-time inorganic carbon dynamics within the porous media and seepage flow. The hillslope carbon flux (0.6–5.1 mg C m–2 h–1) matched weathering rates of natural basalt landscapes (0.4–8.8 mg C m–2 h–1) despite lacking the expected field-based impediments to weathering. After rainfall, a decrease in CO2 concentration ([CO2]) in pore spaces into solution suggested rapid carbon sequestration but slow reactant supply. Persistent low soil [CO2] implied that diffusion limited CO2 supply, while when sufficiently dry, reaction product concentrations limited further weathering. Strong influence of diffusion could cause spatial heterogeneity of weathering even in natural settings, implying that modeling studies need to include variable soil [CO2] to improve carbon cycling estimates associated with potential carbon sequestration methods.

  5. Serra Pelada: the first Amazonian Meteorite fall is a Eucrite (basalt from Asteroid 4-Vesta

    Directory of Open Access Journals (Sweden)

    MARIA ELIZABETH ZUCOLOTTO

    2018-02-01

    Full Text Available ABSTRACT Serra Pelada is the newest Brazilian eucrite and the first recovered fall from Amazonia (State of Pará, Brazil, June 29th 2017. In this paper, we report on its petrography, chemistry, mineralogy and its magnetic properties. Study of four thin sections reveals that the meteorite is brecciated, containing basaltic and gabbroic clasts, as well of recrystallized impact melt, embedded into a fine-medium grained matrix. Chemical analyses suggest that Serra Pelada is a monomict basaltic eucritic breccia, and that the meteorite is a normal member of the HED suite. Our results provide additional geological and compositional information on the lithological diversity of its parent body. The mineralogy of Serra Pelada consists basically of low-Ca pyroxene and high-Ca plagioclase with accessory minerals such as quartz, sulphide (troilite, chromite - ulvöspinel and ilmenite. These data are consistent with the meteorite being an eucrite, a basaltic achondrite and a member of the howardite-eucrite-diogenite (HED clan of meteorites which most likely are from the crust asteroid 4 Vesta.

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

    International Nuclear Information System (INIS)

    Parruzot, Benjamin

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  8. The effect of oxygen fugacity on the solubility of carbon-oxygen fluids in basaltic melt

    Science.gov (United States)

    Pawley, Alison R.; Holloway, John R.; Mcmillan, Paul F.

    1992-01-01

    The solubility of CO2-CO fluids in a midocean ridge basalt have been measured at 1200 C, 500-1500 bar, and oxygen fugacities between NNO and NNO-4. In agreement with results of previous studies, the results reported here imply that, at least at low pressures, CO2 dissolves in basaltic melt only in the form of carbonate groups. The dissolution reaction is heterogeneous, with CO2 molecules in the fluid reacting directly with reactive oxygens in the melt to produce CO3(2-). CO, on the other hand, is insoluble, dissolving neither as carbon, molecular CO, nor CO3(2-). It is shown that, for a given pressure and temperature, the concentration of dissolved carbon-bearing species in basaltic melt in equilibrium with a carbon-oxygen fluid is proportional to the mole fraction of CO2 in the fluid, which is a function of fO2. At low pressures CO2 solubility is a linear function of CO2 fugacity at constant temperatures.

  9. Experimental shock metamorphism of terrestrial basalts: Agglutinate-like particle formation, petrology, and magnetism

    Science.gov (United States)

    Badyukov, Dmitrii D.; Bezaeva, Natalia S.; Rochette, Pierre; Gattacceca, Jérôme; Feinberg, Joshua M.; Kars, Myriam; Egli, Ramon; Raitala, Jouko; Kuzina, Dilyara M.

    2018-01-01

    Hypervelocity impacts occur on bodies throughout our solar system, and play an important role in altering the mineralogy, texture, and magnetic properties in target rocks at nanometer to planetary scales. Here we present the results of hypervelocity impact experiments conducted using a two-stage light-gas gun with 5 mm spherical copper projectiles accelerated toward basalt targets with 6 km s-1 impact velocities. Four different types of magnetite- and titanomagnetite-bearing basalts were used as targets for seven independent experiments. These laboratory impacts resulted in the formation of agglutinate-like particles similar in texture to lunar agglutinates, which are an important fraction of lunar soil. Materials recovered from the impacts were examined using a suite of complementary techniques, including optical and scanning electron microscopy, micro-Raman spectroscopy, and high- and low-temperature magnetometry, to investigate the texture, chemistry, and magnetic properties of newly formed agglutinate-like particles and were compared to unshocked basaltic parent materials. The use of Cu-projectiles, rather than Fe- and Ni-projectiles, avoids magnetic contamination in the final shock products and enables a clearer view of the magnetic properties of impact-generated agglutinates. Agglutinate-like particles show shock features, such as melting and planar deformation features, and demonstrate shock-induced magnetic hardening (two- to seven-fold increases in the coercivity of remanence Bcr compared to the initial target materials) and decreases in low-field magnetic susceptibility and saturation magnetization.

  10. Sorption and desorption reactions of radionuclides with a crushed basalt-bentonite packing material

    International Nuclear Information System (INIS)

    Barney, G.S.; Lane, D.L.; Allen, C.C.; Jones, T.E.

    1985-04-01

    Current design of waste packages for disposal of high-level radioactive wastes in underground basalt formations includes a layer of packing material that surrounds the waste container. One of the functions of this material is to limit the release of radionuclides from a breached container into groundwater by providing a low hydraulic conductivity zone and by sorbing dissolved radionuclides. The objective of this study was to assess the radionuclide sorption capability of a proposed packing material composed of 25% sodium bentonite and 75% crushed basalt (by weight). Sorption and desorption reactions of several important waste radioelements (neptunium, uranium, plutonium, technetium, selenium, and radium) were investigated in the absence of air at 90 0 C. Uranium and neptunium were sorbed by slow reactions that follow first-order kinetics. The reaction rates are probably controlled by reduction of weakly sorbed uranium(VI) and neptunium(V) by ferrous iron in the crushed basalt component. Technetium(VII) was not reduced or sorbed under these conditions. Freundlich sorption and desorption isotherms for a given radionuclide were non-singular and show a strong tendency for sorption hysteresis. Applying the isotherm data to a one-dimensional transport model indicated that hysteretic sorption on the packing material provides an important safety factor in controlling releases of some radionuclides

  11. Hainan mantle plume produced late Cenozoic basaltic rocks in Thailand, Southeast Asia.

    Science.gov (United States)

    Yan, Quanshu; Shi, Xuefa; Metcalfe, Ian; Liu, Shengfa; Xu, Taoyu; Kornkanitnan, Narumol; Sirichaiseth, Thanyapat; Yuan, Long; Zhang, Ying; Zhang, Hui

    2018-02-08

    Intraplate volcanism initiated shortly after the cessation of Cenozoic seafloor spreading in the South China Sea (SCS) region, but the full extent of its influence on the Indochina block has not been well constrained. Here we present major and trace element data and Sr-Nd-Pb-Hf isotope ratios of late Cenozoic basaltic lavas from the Khorat plateau and some volcanic centers in the Paleozoic Sukhothai arc terrane in Thailand. These volcanic rocks are mainly trachybasalts and basaltic trachyandesites. Trace element patterns and Sr-Nd-Pb-Hf isotopic compositions show that these alkaline volcanic lavas exhibit oceanic island basalt (OIB)-like characteristics with enrichments in both large-ion lithophile elements (LILE) and high field strength elements (HFSEs). Their mantle source is a mixture between a depleted Indian MORB-type mantle and an enriched mantle type 2 (EMII). We suggest that the post-spreading intraplate volcanism in the SCS region was induced by a Hainan mantle plume which spread westwards to the Paleozoic Sukhothai arc terrane.

  12. Processing and Material Characterization of Continuous Basalt Fiber Reinforced Ceramic Matrix Composites Using Polymer Derived Ceramics.

    Science.gov (United States)

    Cox, Sarah B.

    2014-01-01

    The need for high performance vehicles in the aerospace industry requires materials which can withstand high loads and high temperatures. New developments in launch pads and infrastructure must also be made to handle this intense environment with lightweight, reusable, structural materials. By using more functional materials, better performance can be seen in the launch environment, and launch vehicle designs which have not been previously used can be considered. The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Polymer matrix composites can be used for temperatures up to 260C. 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 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 the composites. In this study, continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. The oxyacetylene torch testing and three point bend testing have been performed on test panels and the test results are presented.

  13. Microbially mediated alteration of crystalline basalts as identified from analogical reactive percolation experiments

    Science.gov (United States)

    Moore, Rachael; Ménez, Bénédicte; Stéphant, Sylvian; Dupraz, Sébastien; Ranchou-Peyruse, Magali; Ranchou-Peyruse, Anthony; Gérard, Emmanuelle

    2017-04-01

    Alteration in the ocean crust through fluid circulation is an ongoing process affecting the first kilometers and at low temperatures some alteration may be microbially mediated. Hydrothermal activity through the hard rock basement supports diverse microbial communities within the rock by providing nutrient and energy sources. Currently, the impact of basement hosted microbial communities on alteration is poorly understood. In order to identify and quantify the nature of microbially mediated alteration two reactive percolation experiments mimicking circulation of CO2 enriched ground water were performed at 35 °C and 30 bar for 21 days each. The experiments were performed using a crystalline basalt substrate from an earlier drilled deep Icelandic aquifer. One experiment was conducted on sterile rock while the other was conducted with the addition of a microbial inoculate derived from groundwater enrichment cultures obtained from the same aquifer. µCT on the experimental basaltic substrate before and after the reactive percolation experiment along with synchrotron radiation x-ray tomographic microscopy and the mineralogical characterization of resulting material allows for the comparative volumetric quantification of dissolution and precipitation. The unique design of this experiment allows for the identification of alteration which occurs solely abiotically and of microbially mediated alteration. Experimental results are compared to natural basaltic cores from Iceland retrieved following a large field CO2 injection experiment that stimulated microbial activity at depth.

  14. Site selection report basalt waste isolation program near-surface test facility

    International Nuclear Information System (INIS)

    Sharpe, S.D.

    1978-01-01

    A site selection committee was established to review the information gathered on potential sites and to select a site for the Near-Surface Test Facility Phase I. A decision was made to use a site on the north face of Gable Mountain located on the Hanford Site. This site provided convenient access to the Pomona Basalt Flow. This flow was selected for use at this site because it exhibited the characteristics established in the primary criteria. These criteria were: the flows thickness; its dryness; its nearness to the surface; and, its similarities to basalt units which are candidates for the repository. After the selection of the Near-Surface Test Facility Phase I Site, the need arose for an additional facility to demonstrate safe handling, storage techniques, and the physical effects of radioactive materials on an in situ basalt formation. The committee reviewed the sites selected for Phase I and chose the same site for locating Phase II of the Near-Surface Test Facility

  15. First data on Sm-Nd ages of Archean basalts of the Karelian granite-green rock region

    International Nuclear Information System (INIS)

    Sochevanov, N.N.; Arestov, N.A.; Matrenichev, V.A.; Lobach-Zhuchenko, S.B.; Guseva, V.F.

    1991-01-01

    The first results of Sm-Nd dating of metabasalts of two green-rock structures located in the South-East part of the Baltic shield are presented. The age of formation of basalt mass and differentiated mass was 2916±70 and 2960±150 Ma, respectively. Reliable determination of basalt vulcanism manifestation time (2.9 Ga) permits evaluating the lower boundary of formation of granite-green rock complex as 3.0±0.1 Ga

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

    Directory of Open Access Journals (Sweden)

    Abdel-Aal M. Abdel-Karim

    2013-01-01

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

  17. Pb and Sr isotopic systematics of some basalts and sulfides from the East Pacific Rise at 210N (project RITA)

    International Nuclear Information System (INIS)

    Vidal, P.; Clauer, N.

    1981-01-01

    Tholeiitic basalts and sulfide deposits from the 'Cyana' and 'Alvin' diving programs (RITA project) on the East Pacific Rise were analyzed for Pb and Sr isotopes. The basalt data plot within the field defined previously by other East Pacific Rise basalts ( 206 Pb/ 204 Pb: 18.35-18.58; 207 Pb/ 204 Pb: 15.48-15.53; 208 Pb/ 204 Pb: 37.8-38.1; 87 Sr/ 86 Sr: 0.7022-0.7025). Pb, U and Sr contents (approx. equal to 0.5, approx. equal to 0.05 and approx. equal to 110 ppm, respectively) and μ values (approx. equal to 6) are typical of MORB, whereas Th/U ratios (approx. equal to 3.5) are significantly higher. The Pb isotopic ratios of the sulfide samples are very homogeneous ( 206 Pb/ 204 Pb approx. equal to 18.47, 207 Pb/ 204 Pb approx. equal to 15.49, 208 Pb/ 204 Pb approx. equal to 37.90), and plot in the middle of the basalt field. This indicates that the sulfide Pb was derived from the basaltic crust without any significant contribution from either seawater or hemipelagic sediments, and the solutions from which the sulfiedes were deposited had uniform Pb isotopic composition. The Pb contents of three sulfide samples is relatively high (170-1310 ppm). The Sr contents of five sulfide samples are widely scattered from 12 to 210 ppm, with 87 Sr/ 86 Sr ratios intermediate between basaltic and seawater values (0.70554 +- 0.00005 to 0.70795 +- 0.00011). Leaching experiments show that both basalt-derived Sr and seawater Sr were present in the solutions which deposited the sulfides. In some cases, Sr was also adsorbed from seawater onto the sulfides following their deposition. Basalt-derived Sr and seawater Sr are also present in associated non-sulfide phases. (orig.)

  18. Origin of primitive ocean island basalts by crustal gabbro assimilation and multiple recharge of plume-derived melts

    Science.gov (United States)

    Borisova, Anastassia Y.; Bohrson, Wendy A.; Grégoire, Michel

    2017-07-01

    Chemical Geodynamics relies on a paradigm that the isotopic composition of ocean island basalt (OIB) represents equilibrium with its primary mantle sources. However, the discovery of huge isotopic heterogeneity within olivine-hosted melt inclusions in primitive basalts from Kerguelen, Iceland, Hawaii and South Pacific Polynesia islands implies open-system behavior of OIBs, where during magma residence and transport, basaltic melts are contaminated by surrounding lithosphere. To constrain the processes of crustal assimilation by OIBs, we employed the Magma Chamber Simulator (MCS), an energy-constrained thermodynamic model of recharge, assimilation and fractional crystallization. For a case study of the 21-19 Ma basaltic series, the most primitive series ever found among the Kerguelen OIBs, we performed sixty-seven simulations in the pressure range from 0.2 to 1.0 GPa using compositions of olivine-hosted melt inclusions as parental magmas, and metagabbro xenoliths from the Kerguelen Archipelago as wallrock. MCS modeling requires that the assimilant is anatectic crustal melts (P2O5 ≤ 0.4 wt.% contents) derived from the Kerguelen oceanic metagabbro wallrock. To best fit the phenocryst assemblage observed in the investigated basaltic series, recharge of relatively large masses of hydrous primitive basaltic melts (H2O = 2-3 wt%; MgO = 7-10 wt.%) into a middle crustal chamber at 0.2 to 0.3 GPa is required. Our results thus highlight the important impact that crustal gabbro assimilation and mantle recharge can have on the geochemistry of mantle-derived olivine-phyric OIBs. The importance of crustal assimilation affecting primitive plume-derived basaltic melts underscores that isotopic and chemical equilibrium between ocean island basalts and associated deep plume mantle source(s) may be the exception rather than the rule.

  19. Summary and evaluation of hydraulic property data available for the Hanford Site upper basalt confined aquifer system

    International Nuclear Information System (INIS)

    Spane, F.A. Jr.; Vermeul, V.R.

    1994-09-01

    Pacific Northwest Laboratory, as part of the Hanford Site Ground-Water Surveillance Project, examines the potential for offsite migration of contamination within the upper basalt confined aquifer system. For the past 40 years, hydrologic testing of the upper basalt confined aquifer has been conducted by a number of Hanford Site programs. Hydraulic property estimates are important for evaluating aquifer flow characteristics (i.e., ground-water flow patterns, flow velocity, transport travel time). Presented are the first comprehensive Hanford Site-wide summary of hydraulic properties for the upper basalt confined aquifer system (i.e., the upper Saddle Mountains Basalt). Available hydrologic test data were reevaluated using recently developed diagnostic test analysis methods. A comparison of calculated transmissivity estimates indicates that, for most test results, a general correspondence within a factor of two between reanalysis and previously reported test values was obtained. For a majority of the tests, previously reported values are greater than reanalysis estimates. This overestimation is attributed to a number of factors, including, in many cases, a misapplication of nonleaky confined aquifer analysis methods in previous analysis reports to tests that exhibit leaky confined aquifer response behavior. Results of the test analyses indicate a similar range for transmissivity values for the various hydro-geologic units making up the upper basalt confined aquifer. Approximately 90% of the calculated transmissivity values for upper basalt confined aquifer hydrogeologic units occur within the range of 10 0 to 10 2 m 2 /d, with 65% of the calculated estimate values occurring between 10 1 to 10 2 m 2 d. These summary findings are consistent with the general range of values previously reported for basalt interflow contact zones and sedimentary interbeds within the Saddle Mountains Basalt

  20. Summary and evaluation of hydraulic property data available for the Hanford Site upper basalt confined aquifer system

    Energy Technology Data Exchange (ETDEWEB)

    Spane, F.A. Jr.; Vermeul, V.R.

    1994-09-01

    Pacific Northwest Laboratory, as part of the Hanford Site Ground-Water Surveillance Project, examines the potential for offsite migration of contamination within the upper basalt confined aquifer system. For the past 40 years, hydrologic testing of the upper basalt confined aquifer has been conducted by a number of Hanford Site programs. Hydraulic property estimates are important for evaluating aquifer flow characteristics (i.e., ground-water flow patterns, flow velocity, transport travel time). Presented are the first comprehensive Hanford Site-wide summary of hydraulic properties for the upper basalt confined aquifer system (i.e., the upper Saddle Mountains Basalt). Available hydrologic test data were reevaluated using recently developed diagnostic test analysis methods. A comparison of calculated transmissivity estimates indicates that, for most test results, a general correspondence within a factor of two between reanalysis and previously reported test values was obtained. For a majority of the tests, previously reported values are greater than reanalysis estimates. This overestimation is attributed to a number of factors, including, in many cases, a misapplication of nonleaky confined aquifer analysis methods in previous analysis reports to tests that exhibit leaky confined aquifer response behavior. Results of the test analyses indicate a similar range for transmissivity values for the various hydro-geologic units making up the upper basalt confined aquifer. Approximately 90% of the calculated transmissivity values for upper basalt confined aquifer hydrogeologic units occur within the range of 10{sup 0} to 10{sup 2} m{sup 2}/d, with 65% of the calculated estimate values occurring between 10{sup 1} to 10{sup 2} m{sup 2}d. These summary findings are consistent with the general range of values previously reported for basalt interflow contact zones and sedimentary interbeds within the Saddle Mountains Basalt.

  1. Linking geology, fluid chemistry, and microbial activity of basalt- and ultramafic-hosted deep-sea hydrothermal vent environments.

    Science.gov (United States)

    Perner, M; Hansen, M; Seifert, R; Strauss, H; Koschinsky, A; Petersen, S

    2013-07-01

    Hydrothermal fluids passing through basaltic rocks along mid-ocean ridges are known to be enriched in sulfide, while those circulating through ultramafic mantle rocks are typically elevated in hydrogen. Therefore, it has been estimated that the maximum energy in basalt-hosted systems is available through sulfide oxidation and in ultramafic-hosted systems through hydrogen oxidation. Furthermore, thermodynamic models suggest that the greatest biomass potential arises from sulfide oxidation in basalt-hosted and from hydrogen oxidation in ultramafic-hosted systems. We tested these predictions by measuring biological sulfide and hydrogen removal and subsequent autotrophic CO2 fixation in chemically distinct hydrothermal fluids from basalt-hosted and ultramafic-hosted vents. We found a large potential of microbial hydrogen oxidation in naturally hydrogen-rich (ultramafic-hosted) but also in naturally hydrogen-poor (basalt-hosted) hydrothermal fluids. Moreover, hydrogen oxidation-based primary production proved to be highly attractive under our incubation conditions regardless whether hydrothermal fluids from ultramafic-hosted or basalt-hosted sites were used. Site-specific hydrogen and sulfide availability alone did not appear to determine whether hydrogen or sulfide oxidation provides the energy for primary production by the free-living microbes in the tested hydrothermal fluids. This suggests that more complex features (e.g., a combination of oxygen, temperature, biological interactions) may play a role for determining which energy source is preferably used in chemically distinct hydrothermal vent biotopes. © 2013 John Wiley & Sons Ltd.

  2. A potpourri of pristine moon rocks, including a VHK mare basalt and a unique, augite-rich Apollo 17 anorthosite

    Science.gov (United States)

    Warren, P. H.; Shirley, D. N.; Kallemeyn, G. W.

    1986-01-01

    The anorthosite fragment, 76504,18, the first of the Apollo 17's pristine anorthosites, was found to have: (1) a higher ratio of high-Ca pyroxine to low-Ca pyroxene, (2) higher Na in its plagioclase, (3) higher contents of incompatible elements, and (4) a higher Eu/Al ratio in comparison to ferroan anorthosites. With a parent melt having a negative Eu anomaly, 76504,18 closely resembles a typical mare basalt. This anorthosite was among the latest to be formed by plagioclase flotation above a primordial magmasphere; typical mare basalt regions accumulated at about the same time or even earlier. Another fragment 14181c, a very high potassium basalt, was studied and found to be similar to typical Apollo 14 mare basalt though it has a K/La ratio of 1050. It is suggested that this lithology formed after a normal Apollo 14 mare basaltic melt partially assimilated granite. New data for siderphile elements in Apollo 12 mare basalts indicate that only the lowest of earlier data are trustworthy as being free of laboratory contamination.

  3. Geochemistry and petrogenesis of basaltic rocks from the Develidağ volcanic complex, Central Anatolia, Turkey

    Science.gov (United States)

    Kürkcüoglu, Biltan

    2010-01-01

    The Develidağ volcanic zone (DVZ) is a part of the Middle Miocene-Quaternary Cappadocian Volcanic Province (CVP) in central Anatolia. The DVZ is located at the eastern side of the Plio-Quaternary Sultansazlığı pull-apart basin, that opened along the Ecemiş left-lateral strike-slip fault. Towards the south, the volcanic rocks of the DVZ overlie the Paleozoic metamorphic rocks of the Taurus range. Regional stratigraphic studies indicate that volcanic rocks of the DVZ crop out in a ˜N-S trending rectangular-shaped exposure in the middle of which Middle Miocene andesitic rocks are found surrounded by Upper Miocene basaltic rocks. The purpose of this paper is to present basic geochemical data for the DVZ rocks and discuss possible processes of magma generation. The Develidağ basalts are characterized by low LILE (Rb, K, Ba, Th) and high HFSE (Nb,Zr,Hf,Y) contents, whereas the andesites generally have high LILE and HFSE values except for Nb and Zr. Variable abundances of Pb (3.11-12.09 ppm) and U (0.36-2.64 ppm) are associated with high Ba content within the rock suites. Although low Nb/La (0.6-0.7) and relatively high Ba/Nb ratios indicate crustal involvement for the basalts, high Zr/Ba (0.5), Zr/Hf (42-47) and Th/U (3.13-4.69) values imply contributions from an asthenospheric source component. Furthermore, the high Zr/Hf values (>36) are the diagnostic feature of metasomatized mantle (Dupuy et al., 1992; Rudnick et al., 1993). Moreover, multi-element patterns show that Develidağ basalts have similar trace element signatures to those of the US Cascades tholeiites. The ratios of Zr/Hf, Zr/Ba, Nb/Th and Sr/Ce indicate that basaltic rocks are derived from a MORB-like mantle, and calculated melting model reflects generation from a spinel peridotite source (3-4% melting), but the combined effects of melting and assimilation and fractional crystallization (AFC) processes seem to be partially responsible for the relatively evolved rocks. Typical tholeiitic

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

    Science.gov (United States)

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

    2009-12-01

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

  5. Uranium-lead isotope systematics of Mars inferred from the basaltic shergottite QUE 94201

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, A M; Borg, L E; Connelly, J N

    2006-12-22

    Uranium-lead ratios (commonly represented as {sup 238}U/{sup 204}Pb = {mu}) calculated for the sources of martian basalts preserve a record of petrogenetic processes that operated during early planetary differentiation and formation of martian geochemical reservoirs. To better define the range of {mu} values represented by the source regions of martian basalts, we completed U-Pb elemental and isotopic analyses on whole rock, mineral and leachate fractions from the martian meteorite Queen Alexandra Range 94201 (QUE 94201). The whole rock and silicate mineral fractions have unradiogenic Pb isotopic compositions that define a narrow range ({sup 206}Pb/{sup 204}Pb = 11.16-11.61). In contrast, the Pb isotopic compositions of weak HCl leachates are more variable and radiogenic. The intersection of the QUE 94201 data array with terrestrial Pb in {sup 206}Pb/{sup 204}Pb-{sup 207}Pb/{sup 204}Pb-{sup 208}Pb/{sup 204}Pb compositional space is consistent with varying amounts of terrestrial contamination in these fractions. We calculate that only 1-7% contamination is present in the purified silicate mineral and whole rock fractions, whereas the HCl leachates contain up to 86% terrestrial contamination. Despite the contamination, we are able to use the U-Pb data to determine the initial {sup 206}Pb/{sup 204}Pb of QUE 94201 (11.086 {+-} 0.008) and calculate the {mu} value of the QUE 94201 mantle source to be 1.823 {+-} 0.008. This is the lowest {mu} value calculated for any martian basalt source, and, when compared to the highest values determined for martian basalt sources, indicates that {mu} values in martian source reservoirs vary by at least 100%. The range of source {mu} values further indicates that the {mu} value of bulk silicate Mars is approximately three. The amount of variation in the {mu} values of the mantle sources ({mu} {approx} 2-4) is greater than can be explained by igneous processes involving silicate phases alone. We suggest the possibility that a small

  6. Stratigraphical framework of basaltic lavas in Torres Syncline main valley, southern Parana-Etendeka Volcanic Province

    Science.gov (United States)

    Rossetti, Lucas M.; Lima, Evandro F.; Waichel, Breno L.; Scherer, Claiton M.; Barreto, Carla J.

    2014-12-01

    The Paraná-Etendeka Volcanic Province records the volcanism of the Early Cretaceous that precedes the fragmentation of the South-Gondwana supercontinent. Traditionally, investigations of these rocks prioritized the acquisition of geochemical and isotopic data, considering the volcanic stack as a monotonous succession of tabular flows. Torres Syncline is a tectonic structure located in southern Brazil and where the Parana-Etendeka basalts are well preserved. This work provides a detailed analysis of lithofacies and facies architecture, integrated to petrographic and geochemical data. We identified seven distinct lithofacies grouped into four facies associations related to different flow morphologies. The basaltic lava flows in the area can be divided into two contrasting units: Unit I - pahoehoe flow fields; and Unit II - simple rubbly flows. The first unit is build up by innumerous pahoehoe lava flows that cover the sandstones of Botucatu Formation. These flows occur as sheet pahoehoe, compound pahoehoe, and ponded lavas morphologies. Compound lavas are olivine-phyric basalts with intergranular pyroxenes. In ponded lavas and cores of sheet flows coarse plagioclase-phyric basalts are common. The first pahoehoe lavas are more primitive with higher contents of MgO. The emplacement of compound pahoehoe flows is related to low volume eruptions, while sheet lavas were emplaced during sustained eruptions. In contrast, Unit II is formed by thick simple rubbly lavas, characterized by a massive core and a brecciated/rubbly top. Petrographically these flows are characterized by plagioclase-phyric to aphyric basalts with high density of plagioclase crystals in the matrix. Chemically they are more differentiated lavas, and the emplacement is related to sustained high effusion rate eruptions. Both units are low TiO2 and have geochemical characteristics of Gramado magma type. The Torres Syncline main valley has a similar evolution when compared to other Large Igneous Provinces

  7. Magnesium isotopic variation of oceanic island basalts generated by partial melting and crustal recycling

    Science.gov (United States)

    Zhong, Yuan; Chen, Li-Hui; Wang, Xiao-Jun; Zhang, Guo-Liang; Xie, Lie-Wen; Zeng, Gang

    2017-04-01

    Ocean island basalts (OIBs) are geochemically diverse in radiogenic isotopes, a feature that is commonly ascribed to record the chemical heterogeneity of their deep-mantle source, where significant compositional variation relates to variable amounts of ancient recycled crustal material. Although Mg is a major constituent of the mantle, it is still unclear whether Mg isotopes of OIBs predominantly correspond to deep-mantle source heterogeneity or processes such as partial melting. Here, we present Mg isotopic and trace-element compositional data for OIBs from the Hawaii islands, the Louisville seamounts, and for altered oceanic crust samples from the South Pacific. The δ26Mg value range of these OIBs is - 0.29 ± 0.07 ‰ (2SD, n = 17), which is a variation approximately twice as large as the known compositional variation of the peridotitic mantle (- 0.23 ± 0.04 ‰, 2SD). Moreover, alkaline basalt (- 0.31 ± 0.04 ‰, 2SD, n = 12) is relatively enriched in light Mg isotopes compared to tholeiitic basalt (- 0.24 ± 0.02 ‰, 2SD, n = 5). In contrast, altered oceanic crust analyzed in this study has heavier Mg isotopic composition (- 0.18 ± 0.08 ‰, 2SD, n = 13) relative to the basalts and to the peridotitic mantle. An evaluation of our and published data shows that the δ26Mg values of most OIBs negatively correlate with melting-sensitive trace-element ratios, but that they are uncorrelated with source-sensitive elemental ratios. This implies that Mg isotopic variation in most OIBs is largely controlled by variable degrees of partial melting and not by source heterogeneity. Negative correlation between Nb/Zr (or La/Sm) versus δ26Mg suggests that altered oceanic crust with heavier Mg isotopic composition is a more suitable source candidate for common OIBs. However, for a given melting degree, Louisville basalts have lower δ26Mg values than other OIBs, suggesting a different source, e.g. a peridotitic mantle. Modeling calculations suggest that melting of both

  8. The First Paleomagnetic data from the Cambrian basalts of Henrietta Island (De Long Archipelago, Arctic Ocean)

    Science.gov (United States)

    Metelkin, D. V.; Zhdanova, A.; Vernikovskiy, V. A.; Matushkin, N. Y.

    2015-12-01

    Henrietta Island in De Long archipelago (East-Siberian sea) still remains poorly studied geologically but last investigations show that its volcano-sedimentary sequences can help reconstruct tectonic evolution of East Russian Arctic in Early Paleozoic stage. The deposits lying on Precambrian basements are deformed to varying degrees and intruded by mafic dykes.The study was carried out on two basaltic lava flows whose 40Ar/39Ar age is 520.6±9.5 Ma. Previously the age of these basalts was assumed Cretaceous. According to available data the underlaying sediments contain zircons with Cambrian and Ordovician ages but all boundaries between these basalts and other strata are tectonic. So we suppose the age of basalts as Middle Cambrian but more precise geochronological data are required. All magnetic measurements were performed at the Laboratory of Geodynamics and Paleomagnetism of Institute of Petroleum Geology and Geophysics (Novosibirsk). Basalt samples has relatively high magnetic susceptibility values varying from 5x10-4 to 180x10-4SI units. NRM values range is from 3 to 170 mA/m. Petromagnetic parameters including also coercive characteristics point at the good potentially preserving primary magnetization. Stepwise thermal demagnetization permits to isolate characteristic components of magnetization and calculate mean directions in two lava flows: 1. Ds=294.3°, Is=29.1°, K=81.1, α95=5.1; 2. Ds=301.0°, Is=28.3°, K=34.4, α95=7.9). The mean paleomagnetic pole has coordinates: Plat=20.9°, Plong = 42.6°, dp/dm=14.3/7.9. Paleolatitude was defined as 15.3° but the question of the hemisphere for De Long Islands is open yet. In case of south hemisphere in Middle Cambrian according to available paleomagnetic data De Long islands could be placed close to Taimyr margin of Siberia and in case of northern hemisphere they may be located near south (in present-day coordinates) margin of Siberia. The work was supported by grant RFBR 14-05-31399 and Russian Research Fund

  9. Hyper-localized carbon mineralization in diffusion-limited basalt fractures

    Science.gov (United States)

    Menefee, A. H.; Giammar, D.; Ellis, B. R.

    2017-12-01

    Basalt formations could enable secure carbon sequestration through mineral trapping. CO2 injection acidifies formation brines and drives dissolution of the host rock, which releases divalent metal cations that combine with dissolved carbonate ions to form stable carbonate minerals. Here, a series of high-pressure flow-through experiments was conducted to evaluate how transport limitations and geochemical gradients drive microscale carbonation reactions in fractured basalts. To isolate advection- and diffusion-controlled zones, surfaces of saw-cut basalt cores were milled to create one primary flow channel adjoined by four dead-end fracture pathways. In the first experiment, a representative basalt brine (6.3 mM NaHCO3) equilibrated with CO2 (100ºC, 10 MPa) was injected at 1 mL/h under 20 MPa confining stress. The second experiment was conducted under the same physical conditions but [NaHCO3] was elevated to 640 mM, and in the third, temperature was also raised to 150ºC. Effluent chemistry was monitored via ICP-MS to infer dissolution trends and calibrate reactive transport models. Reacted cores were characterized using x-ray computed tomography (xCT), optical microscopy, scanning electron microscopy, and Raman spectroscopy. Carbonation occurred in all experiments but increased in experiments with higher alkalinity and higher temperature. At low [NaHCO3], secondary precipitate coatings formed distinct reaction fronts that varied with distance into dead-end fractures. Reactive transport modeling demonstrated that these reactions fronts were due to sharp gradients in pH and dissolved inorganic carbon. Carbonation was restricted to transport-limited vugs and pores between the confined core surfaces and was highly localized on reactive primary mineral grains (e.g. pyroxene) that contributed major divalent cations. Increasing [NaHCO3] by two orders of magnitude significantly enhanced carbonation and promoted Mg and Fe uptake into carbonates. While xCT scans revealed

  10. Ultrasonic P- and S-Wave Attenuation and Petrophysical Properties of Deccan Flood Basalts, India, as Revealed by Borehole Studies

    Science.gov (United States)

    Vedanti, Nimisha; Malkoti, Ajay; Pandey, O. P.; Shrivastava, J. P.

    2018-03-01

    Petrophysical properties and ultrasonic P- and S-wave attenuation measurements on 35 Deccan basalt core specimens, recovered from Killari borehole site in western India, provide unique reference data-sets for a lesser studied Deccan Volcanic Province. These samples represent 338-m-thick basaltic column, consisting four lava flows each of Ambenali and Poladpur Formations, belonging to Wai Subgroup of the Deccan volcanic sequence. These basalt samples are found to be iron-rich (average FeOT: 13.4 wt%), but relatively poor in silica content (average SiO2: 47.8 wt%). The saturated massive basalt cores are characterized by a mean density of 2.91 g/cm3 (range 2.80-3.01 g/cm3) and mean P- and S-wave velocities of 5.89 km/s (range 5.01-6.50 km/s) and 3.43 km/s (range 2.84-3.69 km/s), respectively. In comparison, saturated vesicular basalt cores show a wide range in density (2.40-2.79 g/cm3) as well as P-wave (3.28-4.78 km/s) and S-wave (1.70-2.95 km/s) velocities. Based on the present study, the Deccan volcanic sequence can be assigned a weighted mean density of 2.74 g/cm3 and a low V p and V s of 5.00 and 3.00 km/s, respectively. Such low velocities in Deccan basalts can be attributed mainly to the presence of fine-grained glassy material, high iron contents, and hydrothermally altered secondary mineral products, besides higher porosity in vesicular samples. The measured Q values in saturated massive basalt cores vary enormously (Q p: 33-1960 and Q s: 35-506), while saturated vesicular basalt samples exhibit somewhat lesser variation in Q p (6-46) as well as Q s (5-49). In general, high-porosity rocks exhibit high attenuation, but we observed the high value of attenuation in some of the massive basalt core samples also. In such cases, energy loss is mainly due to the presence of fine-grained glassy material as well as secondary alteration products like chlorophaeite, that could contribute to intrinsic attenuation. Dominance of weekly bound secondary minerals might also be

  11. Paleoproterozoic arc basalt-boninite-high magnesian andesite-Nb enriched basalt association from the Malangtoli volcanic suite, Singhbhum Craton, eastern India: Geochemical record for subduction initiation to arc maturation continuum

    Science.gov (United States)

    Rajanikanta Singh, M.; Manikyamba, C.; Ganguly, Sohini; Ray, Jyotisankar; Santosh, M.; Dhanakumar Singh, Th.; Chandan Kumar, B.

    2017-02-01

    The Singhbhum Craton of eastern India preserves distinct signatures of ultramafic-mafic-intermediate-felsic magmatism of diverse geodynamic affiliations spanning from Paleo-Mesoarchean to Proterozoic. Here we investigate the 2.25 Ga Malangtoli volcanic rocks that are predominantly clinopyroxene- and plagioclase-phyric, calc-alkaline in nature, display basalt-basaltic andesite compositions, and preserve geochemical signatures of subduction zone magmatism. Major, trace and rare earth element characteristics classify the Malangtoli volcanic rocks as arc basalts, boninites, high magnesian andesites (HMA) and Nb enriched basalts (NEB). The typical LILE enriched-HFSE depleted geochemical attributes of the arc basalts corroborate a subduction-related origin. The boninitic rocks have high Mg# (0.8), MgO (>25 wt.%), Ni and Cr contents, high Al2O3/TiO2 (>20), Zr/Hf and (La/Sm)N (>1) ratios with low (Gd/Yb)N (54 wt.%), MgO (>6 wt.%), Mg# (0.47) with elevated Cr, Co, Ni and Th contents, depleted (Nb/Th)N, (Nb/La)N, high (Th/La)N and La/Yb (Y with low Sr/Y. The NEBs have higher Nb contents (6.3-24 ppm), lower magnitude of negative Nb anomalies with high (Nb/Th)pm = 0.28-0.59 and (Nb/La)pm = 0.40-0.69 and Nb/U = 2.8-34.4 compared to normal arc basalts [Nb = generation of NEB. Thus, the arc basalt-boninite-HMA-NEB association from Malangtoli volcanic suite in Singhbhum Craton preserves the signature of a complete spectrum of Paleoproterozoic active convergent margin processes spanning from subduction initiation to arc maturation.

  12. PETRO- AND PALEOMAGNETIC STUDIES OF BASALTS OF THE UPPER DEVONIAN APPAINSKAYA SUITE (WESTERN YAKUTIA

    Directory of Open Access Journals (Sweden)

    К. M. Konstantinov

    2016-01-01

    Full Text Available Introduction. One of the main tasks of paleomagnetic studies is to obtain a framework of reference poles for calculating the kinematic characteristics of lithospheric taxones as a basis for geodynamic reconstructions. Each paleomagnetic reference point must have a precise (±10 Ma geochronological dating and a maximum paleomagnetic reliability index. A correct paleomagnetic pole (PMP can be obtained from the data of geochronological and paleomagnetic studies conducted in one and the same geological object, such as a suite, an intrusive complex etc. In the Yakutian diamondiferous province (YDP, such objects include basalt nappes of the Upper Devonian Appainskaya suite, which stratigraphic position is undoubted (Fran, 385–375 Ma.Geological setting (in brief. In the eastern segments of the Siberian platform, a powerful cycle of tectonic and magmatic activity in the Middle Paleozoic produced transgressive and sheet intrusions, volcanic pipes, lava and tuff formations comprised of basites, as well as all the currently known industrial diamondiferous kimberlite bodies. Magmatic activity of basites was associated with formation of paleorift systems, including the largest one, Viluyi paleorift (Fig. 1. In the Middle Paleozoic, the geodynamic setting for magmatism and rifting was determined by the plume-lithosphere interaction. The rise of the plume’s matter underneath the thinned lithosphere was accompanied by decompression melting and formation of basaltic magmas in large volumes.We have studied basalts of the Appainskaya suite which were sampled from the Ygyatta and Markha river valleys (Fig. 2. In the coastal outcrops at the Ygyatta river, two nappes are observed, a (stratigraphically lower outcrop 17÷23/10 containing plagiophyre palagonite basalts (upper five meters are outcropped, and an upper outcrop 16/10 containing olivinophyric palagonite basalts (upper three meters are outcropped. In the coastal outcrops of the Markha river, from the

  13. Field-trip guide to Columbia River flood basalts, associated rhyolites, and diverse post-plume volcanism in eastern Oregon

    Science.gov (United States)

    Ferns, Mark L.; Streck, Martin J.; McClaughry, Jason D.

    2017-08-09

    The Miocene Columbia River Basalt Group (CRBG) is the youngest and best preserved continental flood basalt province on Earth, linked in space and time with a compositionally diverse succession of volcanic rocks that partially record the apparent emergence and passage of the Yellowstone plume head through eastern Oregon during the late Cenozoic. This compositionally diverse suite of volcanic rocks are considered part of the La Grande-Owyhee eruptive axis (LOEA), an approximately 300-kilometer-long (185 mile), north-northwest-trending, middle Miocene to Pliocene volcanic belt located along the eastern margin of the Columbia River flood basalt province. Volcanic rocks erupted from and preserved within the LOEA form an important regional stratigraphic link between the (1) flood basalt-dominated Columbia Plateau on the north, (2) bimodal basalt-rhyolite vent complexes of the Owyhee Plateau on the south, (3) bimodal basalt-rhyolite and time-transgressive rhyolitic volcanic fields of the Snake River Plain-Yellowstone Plateau, and (4) the High Lava Plains of central Oregon.This field-trip guide describes a 4-day geologic excursion that will explore the stratigraphic and geochemical relationships among mafic rocks of the Columbia River Basalt Group and coeval and compositionally diverse volcanic rocks associated with the early “Yellowstone track” and High Lava Plains in eastern Oregon. Beginning in Portland, the Day 1 log traverses the Columbia River gorge eastward to Baker City, focusing on prominent outcrops that reveal a distal succession of laterally extensive, large-volume tholeiitic flood lavas of the Grande Ronde, Wanapum, and Saddle Mountains Basalt formations of the CRBG. These “great flows” are typical of the well-studied flood basalt-dominated Columbia Plateau, where interbedded silicic and calc-alkaline lavas are conspicuously absent. The latter part of Day 1 will highlight exposures of middle to late Miocene silicic ash-flow tuffs, rhyolite domes, and

  14. INVESTIGATION OF BASALT-RADIONUCLIDE DISTRIBUTION COEFFICIENTS: FISCAL YEAR 1980 ANNUAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Ames, L. L.; McGarrah, J. E.

    1980-12-01

    The Basalt Waste Isolation Project (Rockwell Hanford Operations) is conducting a safety assessment of nuclear waste storage in a repository on the Hanford Site. Pacific Northwest Laboratory, in support of the assessment effort, is generating radionuclide distribution coefficient data between simulated groundwaters and basalts and their secondary mineral products under the range of physicochemical conditions expected in a repository in basalt. Experimental radionuclide distribution coefficients were determined for crushed Pomona, Flow E, and Umtanum basalts at 23°, 60°, 150°, and 300°C at both normal oxygen partial pressure (~0.2 atm) and lower oxygen partial pressure (~10{sup -7} atm), using a static technique. Little or no changes in distribution coefficients were noted for selenium, uranium, technetium, neptunium, or plutonium over the oxygen partial pressure range noted above. Sodium dithionite and hydrazine are now under study as system additives to lower Eh to -0.3 to -0.5 V, the conditions expected to prevail in the closed repository in basalt. Radium, strontium, cesium, and americium are not expected to change oxidation states under repository conditions, while iodine remains an anion in either oxidation state. Lowering the system Eh to the -0.3 to -0.5 V expected in a repository in basalt should result in an oxidation state change and enhanced removal from solution for selenium, uranium, technetium, neptunium, and plutonium. Sorption of iodine was not affected by the Eh changes. Temperature change effects on most radionuclide distribution coefficient (Kd) values over the 23° to 300°C range were major with the exception of iodine and technetium, neither of which were appreciably sorbed at normal to ~10{sup -7} atm oxygen partial pressure. Uranium Kd values increased with an increase in temperature. In addition, uranium Kd values at 23°C decrease by an order of magnitude in response to added CO{sub 3}{sup 2-} in the solution. Cesium basalt Kd values

  15. Rate of deformation in the Pasco Basin during the Miocene as determined by distribution of Columbia River basalt flows

    International Nuclear Information System (INIS)

    Reidel, S.P.; Ledgerwood, R.K.; Myers, C.W.; Jones, M.G.; Landon, R.D.

    1980-03-01

    Detailed mapping of over 8000 square kilometers and logs from 20 core holes were used to determine the distribution and thickness of basalt flows and interbeds in the Pasco Basin. The data indicate the high-MgO Grande Ronde Basalt and Wanapum Basalt thicken from the northeast to the southwest. Deformation began in late Frenchman Springs time in the Saddle Mountains along a northwest-southeast trend and in Roza time along an east-west trend. By late Wanapum time, basalt flows were more restricted on the east side. Saddle Mountains Basalt flows spread out in the basin from narrow channels to the east. The Umatilla Member entered from the southeast and is confined to the south-central basin, while the Wilbur Creek, Asotin, Esquatzel, Pomona, and Elephant Mountain Members entered from the east and northeast. The distribution of these members is controlled by flow volume, boundaries of other flows, and developing ridges. The Wilbur Creek, Asotin, and Esquatzel flows exited from the basin in a channel along the northern margin of the Umatilla flow, while the Pomona and Elephant Mountain flows exited between Umtanum Ridge and Wallula Gap. The thickness of sedimentary interbeds and basalt flows indicated subsidence and/or uplift began in post-Grande Ronde time (14.5 million years before present) and continued through Saddle Mountains time (10.5 million years before present). Maximum subsidence occurred 40 kilometers (24 miles) north of Richland, Washington with an approximate rate of 25 meters (81 feet) per million years during the eruption of the basalt. Maximum uplift along the developing ridges was 70 meters (230 feet) per million years

  16. Origin of Columbia River flood basalt controlled by propagating rupture of the Farallon slab.

    Science.gov (United States)

    Liu, Lijun; Stegman, Dave R

    2012-02-15

    The origin of the Steens-Columbia River (SCR) flood basalts, which is presumed to be the onset of Yellowstone volcanism, has remained controversial, with the proposed conceptual models involving either a mantle plume or back-arc processes. Recent tomographic inversions based on the USArray data reveal unprecedented detail of upper-mantle structures of the western USA and tightly constrain geodynamic models simulating Farallon subduction, which has been proposed to influence the Yellowstone volcanism. Here we show that the best-fitting geodynamic model depicts an episode of slab tearing about 17 million years ago under eastern Oregon, where an associated sub-slab asthenospheric upwelling thermally erodes the Farallon slab, leading to formation of a slab gap at shallow depth. Driven by a gradient of dynamic pressure, the tear ruptured quickly north and south and within about two million years covering a distance of around 900 kilometres along all of eastern Oregon and northern Nevada. This tear would be consistent with the occurrence of major volcanic dikes during the SCR-Northern Nevada Rift flood basalt event both in space and time. The model predicts a petrogenetic sequence for the flood basalt with sources of melt starting from the base of the slab, at first remelting oceanic lithosphere and then evolving upwards, ending with remelting of oceanic crust. Such a progression helps to reconcile the existing controversies on the interpretation of SCR geochemistry and the involvement of the putative Yellowstone plume. Our study suggests a new mechanism for the formation of large igneous provinces.

  17. Rubbly Pahoehoe: Implication for Flood Basalt Eruptions and their Atmospheric Effects

    Science.gov (United States)

    Keszthelyi, L.; Keszthelyi, L.; Thordarson, T.; Self, S.

    2001-12-01

    Rubbly pahoehoe flows consist of a brecciated flow top, a pahoehoe base, and an interior similar to inflated pahoehoe flows. Rubbly pahoehoe flows can be found in many localities, making up ~20% of the Columbia River Basalt Group, ~50% of the lavas drilled on the Kerguelen Plateau, and a substantial fraction of the Icelandic lava flows. They are rare in the tholeiitic shield portions of the Hawaiian volcanoes, but are more common in the alkalic flows. They also appear to be the dominant type of Martian flood lava flow. Based primarily on observations from the 1873-1874 Laki Flow Field in Iceland, we suggest that rubbly pahoehoe flows form when the flux of lava within an inflating pahoehoe flow is so large that it rafts away the upper crust. This crust is then broken into large slabs and fragmented lobes, intruded by liquid lava from below, and folded into pressure ridges. This brecciation process quickly builds an insulating crust; for the Laki case a crust >4 m thick developed in less than a week. This rapid formation of a thick insulating crust allows lava to be transported over great distances with minimal cooling in eruptions lasting only weeks-months. Flood basalt flows emplaced in this manner could have had eruption rates on the order of 104 - 105 m^{3}s^{-1}. If active fissure segments were of the order of 10 km long, the volcanic plumes should have risen 9-16 km -- penetrating the stratosphere in most cases. The injection of \\sim10 Gt of SO_{2}$, F, and Cl into the stratosphere could have had serious climatic effects, thus further strengthening the plausible link between flood basalt eruptions and mass extinctions.

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

    Science.gov (United States)

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

    2013-01-01

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

  19. Magmatic inclusions in rhyolites, contaminated basalts, and compositional zonation beneath the Coso volcanic field, California

    Science.gov (United States)

    Bacon, C.R.; Metz, J.

    1984-01-01

    Basaltic lava flows and high-silica rhyolite domes form the Pleistocene part of the Coso volcanic field in southeastern California. The distribution of vents maps the areal zonation inferred for the upper parts of the Coso magmatic system. Subalkalic basalts (Coso volcanic field contain sparse andesitic inclusions (55-61% SiO2). Pillow-like forms, intricate commingling and local diffusive mixing of andesite and rhyolite at contacts, concentric vesicle distribution, and crystal morphologies indicative of undercooling show that inclusions were incorporated in their rhyolitic hosts as blobs of magma. Inclusions were probably dispersed throughout small volumes of rhyolitic magma by convective (mechanical) mixing. Inclusion magma was formed by mixing (hybridization) at the interface between basaltic and rhyolitic magmas that coexisted in vertically zoned igneous systems. Relict phenocrysts and the bulk compositions of inclusions suggest that silicic endmembers were less differentiated than erupted high-silica rhyolite. Changes in inferred endmembers of magma mixtures with time suggest that the steepness of chemical gradients near the silicic/mafic interface in the zoned reservoir may have decreased as the system matured, although a high-silica rhyolitic cap persisted. The Coso example is an extreme case of large thermal and compositional contrast between inclusion and host magmas; lesser differences between intermediate composition magmas and inclusions lead to undercooling phenomena that suggest smaller ??T. Vertical compositional zonation in magma chambers has been documented through study of products of voluminous pyroclastic eruptions. Magmatic inclusions in volcanic rocks provide evidence for compositional zonation and mixing processes in igneous systems when only lava is erupted. ?? 1984 Springer-Verlag.

  20. Rangitoto Volcano Drilling Project: Life of a Small 'Monogenetic' Basaltic Shield in the Auckland Volcanic Field

    Science.gov (United States)

    Shane, P. A. R.; Linnell, T.; Lindsay, J. M.; Smith, I. E.; Augustinus, P. M.; Cronin, S. J.

    2014-12-01

    Rangitoto is a small basaltic shield volcano representing the most recent and most voluminous episode of volcanism in the Auckland Volcanic Field, New Zealand. Auckland City is built on the field, and hence, Rangitoto's importance in hazard-risk modelling. The symmetrical edifice, ~6 km wide and 260 m high, has volume of 1.78 km3. It comprises summit scoria cones and a lava field. However, the lack of deep erosion dissection has prevented the development of an eruptive stratigraphy. Previous studies suggested construction in a relatively short interval at 550-500 yrs BP. However, microscopic tephra have been interpreted as evidence of intermittent activity from 1498 +/- 140 to 504 +/- 6 yrs BP, a longevity of 1000 years. A 150-m-deep hole was drilled through the edifice in February 2014 to obtain a continuous core record. The result is an unparalleled stratigraphy of the evolution of a small shield volcano. The upper 128 m of core comprises at least 27 lava flows with thicknesses in the range 0.3-15 m, representing the main shield-building phase. Underlying marine sediments are interbedded with 8 m of pyroclastic lapilli, and a thin lava flow, representing the explosive phreatomagmatic birth of the volcano. Preliminary geochemical analyses reveal suite of relatively uniform transitional basalts (MgO = 8.1 to 9.7 wt %). However, 4 compositional groups are distinguished that were erupted in sequential order. High-MgO magmas were erupted first, followed by a two more heterogeneous groups displaying differentiation trends with time. Finally, distinct low-MgO basalts were erupted. Each magma type appears to represent a new magma batch. The core places the magma types in a time series, which can be correlated to the surface lava field. Hence, allowing a geometrical reconstruction of the shield growth. Additional petrologic investigations are providing insight to magmatic ascent processes, while radiocarbon and paleomagnetic secular variation studies will reveal the

  1. The role of porosity in thermal inertia variations on basaltic lavas

    Science.gov (United States)

    Zimbelman, James R.

    1986-01-01

    Thermal inertia, defined as the square root of the product of thermal conductivity, density, and specific heat, has been noted to vary in inverse proportion to porosity in Hawaiian basalts. It is presently suggested that porosities of the order of more than 80 percent are required if the low thermal inertias observed in Martian shield volcanoes are the result of pristine lava flow surface properties. An aeolian origin is held to be most likely in view of thermal measurements on Mars; the volcanic surfaces in question are anticipated to have a short lifetime in their environment.

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

    Science.gov (United States)

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

    2007-05-01

    This study used batch reactors to characterize the rates and mechanisms of elemental release during the interaction of a single bacterial species ( Burkholderia fungorum) with Columbia River Flood Basalt at T = 28 °C for 36 days. We primarily examined the release of Ca, Mg, P, Si, and Sr under a variety of biotic and abiotic conditions with the aim of evaluating how actively metabolizing bacteria might influence basalt weathering on the continents. Four days after inoculating P-limited reactors (those lacking P in the growth medium), the concentration of viable planktonic cells increased from ˜10 4 to 10 8 CFU (Colony Forming Units)/mL, pH decreased from ˜7 to 4, and glucose decreased from ˜1200 to 0 μmol/L. Mass-balance and acid-base equilibria calculations suggest that the lowered pH resulted from either respired CO 2, organic acids released during biomass synthesis, or H + extrusion during NH4+ uptake. Between days 4 and 36, cell numbers remained constant at ˜10 8 CFU/mL and pH increased to ˜5. Purely abiotic control reactors as well as control reactors containing inert cells (˜10 8 CFU/mL) showed constant glucose concentrations, thus confirming the absence of biological activity in these experiments. The pH of all control reactors remained near-neutral, except for one experiment where the pH was initially adjusted to 4 but rapidly rose to 7 within 2 days. Over the entire 36 day period, P-limited reactors containing viable bacteria yielded the highest Ca, Mg, Si, and Sr release rates. Release rates inversely correlate with pH, indicating that proton-promoted dissolution was the dominant reaction mechanism. Both biotic and abiotic P-limited reactors displayed low P concentrations. Chemical analyses of bacteria collected at the end of the experiments, combined with mass-balances between the biological and fluid phases, demonstrate that the absence of dissolved P in the biotic reactors resulted from microbial P uptake. The only P source in the basalt is a

  3. Investigating lava-substrate interactions through flow experiments with syrup, wax, and molten basalt

    Science.gov (United States)

    Rumpf, M. E.; Lev, E.

    2015-12-01

    Among the many factors influencing the complex process of lava flow emplacement, the interaction with the substrate onto which flow is emplaced plays a central role. Lava flows are rarely emplaced onto smooth or regular surfaces. For example, at Kīlauea Volcano, Hawai'i, lava flows regularly flow over solid rock, vegetation, basaltic or silica sand, and man-made materials, including asphalt and concrete. In situ studies of lava-substrate interactions are inherently difficult, and often dangerous, to carry-out, requiring the design of controllable laboratory experiments. We investigate the effects of substrate grain size, cohesion, and roughness on flow mobility and morphology through a series of flow experiments using analog materials and molten basalt. We have developed a series of experiments that allow for adjustable substrate parameters and analyze their effects on lava flow emplacement. The first set of experiments are performed at the Fluids Mechanics Laboratory at the Lamont-Doherty Earth Observatory and focus on two analog materials: polyethylene glycol (PEG), a commercially available wax, and corn syrup. The fluids were each extruded onto a series of scaled substrate beds to replicate the emplacement of lava in a natural environment. Preliminary experiments demonstrated that irregular topography, particularly topography with a height amplitude similar to that of the flow itself, can affect flow morphology, width, and velocity by acting as local barriers or culverts to the fluid. This is expected from observations of fluid flow in natural environments. A follow-up set of experiments will be conducted in Fall 2015 at the Syracuse University (SU) Lava Project Lab. In this set, we will pour molten basalt directly onto a series of substrates representing natural environments found on the Earth and other rocky bodies in the Solar System. These experiments will allow for analysis of the effects of basaltic composition and high temperatures on lava-substrate heat

  4. Al-augite and Cr-diopside ultramafic xenoliths in basaltic rocks from western United States

    Science.gov (United States)

    Wilshire, H.G.; Shervais, J.W.

    1975-01-01

    Ultramafic xenoliths in basalts from the western United States are divided into Al-augite and Cr-diopside groups. The Al-augite group is characterized by Al, Ti-rich augites, comparatively Fe-rich olivine and orthopyroxene, and Al-rich spinel, the Cr-diopside group by Cr-rich clinopyroxene and spinel and by Mg-rich olivine and pyroxenes. Both groups have a wide range of subtypes, but the Al-augite group is dominated by augite-rich varieties, and the Cr-diopside group by olivine-rich lherzolites. ?? 1975.

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

    Science.gov (United States)

    Brusentseva, T. A.

    2017-10-01

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

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

    Science.gov (United States)

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

    2015-09-01

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

  7. Earth's evolving subcontinental lithospheric mantle: inferences from LIP continental flood basalt geochemistry

    Science.gov (United States)

    Greenough, John D.; McDivitt, Jordan A.

    2017-06-01

    Archean and Proterozoic subcontinental lithospheric mantle (SLM) is compared using 83 similarly incompatible element ratios (SIER; minimally affected by % melting or differentiation, e.g., Rb/Ba, Nb/Pb, Ti/Y) for >3700 basalts from ten continental flood basalt (CFB) provinces representing nine large igneous provinces (LIPs). Nine transition metals (TM; Fe, Mn, Sc, V, Cr, Co, Ni, Cu, Zn) in 102 primitive basalts (Mg# = 0.69-0.72) from nine provinces yield additional SLM information. An iterative evaluation of SIER values indicates that, regardless of age, CFB transecting Archean lithosphere are enriched in Rb, K, Pb, Th and heavy REE(?); whereas P, Ti, Nb, Ta and light REE(?) are higher in Proterozoic-and-younger SLM sources. This suggests efficient transfer of alkali metals and Pb to the continental lithosphere perhaps in association with melting of subducted ocean floor to form Archean tonalite-trondhjemite-granodiorite terranes. Titanium, Nb and Ta were not efficiently transferred, perhaps due to the stabilization of oxide phases (e.g., rutile or ilmenite) in down-going Archean slabs. CFB transecting Archean lithosphere have EM1-like SIER that are more extreme than seen in oceanic island basalts (OIB) suggesting an Archean SLM origin for OIB-enriched mantle 1 (EM1). In contrast, OIB high U/Pb (HIMU) sources have more extreme SIER than seen in CFB provinces. HIMU may represent subduction-processed ocean floor recycled directly to the convecting mantle, but to avoid convective homogenization and produce its unique Pb isotopic signature may require long-term isolation and incubation in SLM. Based on all TM, CFB transecting Proterozoic lithosphere are distinct from those cutting Archean lithosphere. There is a tendency for lower Sc, Cr, Ni and Cu, and higher Zn, in the sources for Archean-cutting CFB and EM1 OIB, than Proterozoic-cutting CFB and HIMU OIB. All CFB have SiO2 (pressure proxy)-Nb/Y (% melting proxy) relationships supporting low pressure, high % melting

  8. Phreatic explosions during basaltic fissure eruptions: Kings Bowl lava field, Snake River Plain, USA

    Science.gov (United States)

    Hughes, Scott S.; Kobs Nawotniak, Shannon E.; Sears, Derek W. G.; Borg, Christian; Garry, William Brent; Christiansen, Eric H.; Haberle, Christopher W.; Lim, Darlene S. S.; Heldmann, Jennifer L.

    2018-02-01

    Physical and compositional measurements are made at the 7 km-long ( 2200 years B.P.) Kings Bowl basaltic fissure system and surrounding lava field in order to further understand the interaction of fissure-fed lavas with phreatic explosive events. These assessments are intended to elucidate the cause and potential for hazards associated with phreatic phases that occur during basaltic fissure eruptions. In the present paper we focus on a general understanding of the geological history of the site. We utilize geospatial analysis of lava surfaces, lithologic and geochemical signatures of lava flows and explosively ejected blocks, and surveys via ground observation and remote sensing. Lithologic and geochemical signatures readily distinguish between Kings Bowl and underlying pre-Kings Bowl lava flows, both of which comprise phreatic ejecta from the Kings Bowl fissure. These basalt types, as well as neighboring lava flows from the contemporaneous Wapi lava field and the older Inferno Chasm vent and outflow channel, fall compositionally within the framework of eastern Snake River Plain olivine tholeiites. Total volume of lava in the Kings Bowl field is estimated to be 0.0125 km3, compared to a previous estimate of 0.005 km3. The main (central) lava lake lost a total of 0.0018 km3 of magma by either drain-back into the fissure system or breakout flows from breached levees. Phreatic explosions along the Kings Bowl fissure system occurred after magma supply was cut off, leading to fissure evacuation, and were triggered by magma withdrawal. The fissure system produced multiple phreatic explosions and the main pit is accompanied by others that occur as subordinate pits and linear blast corridors along the fissure. The drop in magma supply and the concomitant influx of groundwater were necessary processes that led to the formation of Kings Bowl and other pits along the fissure. A conceptual model is presented that has relevance to the broader range of low-volume, monogenetic

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

    OpenAIRE

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

  11. TRU waste form studies with special reference to iron-enriched basalt: 1980. Annual report

    International Nuclear Information System (INIS)

    Flinn, J.E.; Henslee, S.P.; Kelsey, P.V. Jr.

    1981-06-01

    Material studies were performed on iron-enriched basalt (IEB) as a waste form containment medium for transuranic wastes. Specimens from laboratory scale, as well as large scale melts, were used in the evaluation. The studies included melting and casting, slag-refractory interaction, slag fruit assessments, volatility of sodium salts from IEB melts, chemical and structure homogeneity, metallic dissolution tests, physical properties, and devitrification associated with the development of mineral phases. In addition, durability tests, which included leaching and mechanical behavior, were performed

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

    Science.gov (United States)

    Allard, Patrick

    2010-01-01

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

  13. Earth's evolving subcontinental lithospheric mantle: inferences from LIP continental flood basalt geochemistry

    Science.gov (United States)

    Greenough, John D.; McDivitt, Jordan A.

    2018-04-01

    Archean and Proterozoic subcontinental lithospheric mantle (SLM) is compared using 83 similarly incompatible element ratios (SIER; minimally affected by % melting or differentiation, e.g., Rb/Ba, Nb/Pb, Ti/Y) for >3700 basalts from ten continental flood basalt (CFB) provinces representing nine large igneous provinces (LIPs). Nine transition metals (TM; Fe, Mn, Sc, V, Cr, Co, Ni, Cu, Zn) in 102 primitive basalts (Mg# = 0.69-0.72) from nine provinces yield additional SLM information. An iterative evaluation of SIER values indicates that, regardless of age, CFB transecting Archean lithosphere are enriched in Rb, K, Pb, Th and heavy REE(?); whereas P, Ti, Nb, Ta and light REE(?) are higher in Proterozoic-and-younger SLM sources. This suggests efficient transfer of alkali metals and Pb to the continental lithosphere perhaps in association with melting of subducted ocean floor to form Archean tonalite-trondhjemite-granodiorite terranes. Titanium, Nb and Ta were not efficiently transferred, perhaps due to the stabilization of oxide phases (e.g., rutile or ilmenite) in down-going Archean slabs. CFB transecting Archean lithosphere have EM1-like SIER that are more extreme than seen in oceanic island basalts (OIB) suggesting an Archean SLM origin for OIB-enriched mantle 1 (EM1). In contrast, OIB high U/Pb (HIMU) sources have more extreme SIER than seen in CFB provinces. HIMU may represent subduction-processed ocean floor recycled directly to the convecting mantle, but to avoid convective homogenization and produce its unique Pb isotopic signature may require long-term isolation and incubation in SLM. Based on all TM, CFB transecting Proterozoic lithosphere are distinct from those cutting Archean lithosphere. There is a tendency for lower Sc, Cr, Ni and Cu, and higher Zn, in the sources for Archean-cutting CFB and EM1 OIB, than Proterozoic-cutting CFB and HIMU OIB. All CFB have SiO2 (pressure proxy)-Nb/Y (% melting proxy) relationships supporting low pressure, high % melting

  14. Cumulate xenoliths from St. Vincent, Lesser Antilles Island Arc: a window into upper crustal differentiation of mantle-derived basalts

    Science.gov (United States)

    Tollan, P. M. E.; Bindeman, I.; Blundy, J. D.

    2012-02-01

    In order to shed light on upper crustal differentiation of mantle-derived basaltic magmas in a subduction zone setting, we have determined the mineral chemistry and oxygen and hydrogen isotope composition of individual cumulus minerals in plutonic blocks from St. Vincent, Lesser Antilles. Plutonic rock types display great variation in mineralogy, from olivine-gabbros to troctolites and hornblendites, with a corresponding variety of cumulate textures. Mineral compositions differ from those in erupted basaltic lavas from St. Vincent and in published high-pressure (4-10 kb) experimental run products of a St. Vincent high-Mg basalt in having higher An plagioclase coexisting with lower Fo olivine. The oxygen isotope compositions (δ18O) of cumulus olivine (4.89-5.18‰), plagioclase (5.84-6.28‰), clinopyroxene (5.17-5.47‰) and hornblende (5.48-5.61‰) and hydrogen isotope composition of hornblende (δD = -35.5 to -49.9‰) are all consistent with closed system magmatic differentiation of a mantle-derived basaltic melt. We employed a number of modelling exercises to constrain the origin of the chemical and isotopic compositions reported. δ18OOlivine is up to 0.2‰ higher than modelled values for closed system fractional crystallisation of a primary melt. We attribute this to isotopic disequilibria between cumulus minerals crystallising at different temperatures, with equilibration retarded by slow oxygen diffusion in olivine during prolonged crustal storage. We used melt inclusion and plagioclase compositions to determine parental magmatic water contents (water saturated, 4.6 ± 0.5 wt% H2O) and crystallisation pressures (173 ± 50 MPa). Applying these values to previously reported basaltic and basaltic andesite lava compositions, we can reproduce the cumulus plagioclase and olivine compositions and their associated trend. We conclude that differentiation of primitive hydrous basalts on St. Vincent involves crystallisation of olivine and Cr-rich spinel at depth

  15. REE and Isotopic Compositions of Lunar Basalts Demonstrate Partial Melting of Hybridized Mantle Sources after Cumulate Overturn is Required

    Science.gov (United States)

    Dygert, N. J.; Liang, Y.

    2017-12-01

    Lunar basalts maintain an important record of the composition of the lunar interior. Much of our understanding of the Moon's early evolution comes from studying their petrogenesis. Recent experimental work has advanced our knowledge of major and trace element fractionation during lunar magma ocean (LMO) crystallization [e.g., 1-3], which produced heterogeneous basalt sources in the Moon's mantle. With the new experimental constraints, we can evaluate isotopic and trace element signatures in lunar basalts in unprecedented detail, refining inferences about the Moon's dynamic history. Two petrogenetic models are invoked to explain the compositions of the basalts. The assimilation model argues they formed as primitive melts of early LMO cumulates that assimilated late LMO cumulates as they migrated upward. The cumulate overturn model argues that dense LMO cumulates sank into the lunar interior, producing hybridized sources that melted to form the basalts. Here we compare predicted Ce/Yb and Hf and Nd isotopes of partial melts of LMO cumulates with measured compositions of lunar basalts to evaluate whether they could have formed by end-member petrogenetic models. LMO crystallization models suggest all LMO cumulates have chondrite normalized Ce/Yb 1.5; these could not have formed by assimilation of any LMO cumulate or residual liquid (or KREEP basalt, which has isotopically negative ɛNd and ɛHf). In contrast, basalt REE patterns and isotopes can easily be modeled assuming partial melting of hybridized mantle sources, indicating overturn may be required. A chemical requirement for overturn independently confirms that late LMO cumulates are sufficiently low in viscosity to sink into the lunar interior, as suggested by recent rock deformation experiments [4]. Overturned, low viscosity late LMO cumulates would be relatively stable around the core [5]. High Ce/Yb basalts require that overturned cumulates were mixed back into the overlying mantle by convection within a few

  16. Source implications for the different geochemical features of recent basaltic rocks from the northernmost part of the Cappadocian region, Turkey

    Science.gov (United States)

    Kurkcuoglu, Biltan; Yurur, Tekin

    2017-04-01

    Extensive magmatic activities developed since middle-Miocene, in the Cappadocian Region of Central Anatolia in Turkey. The nature and the sources of the magmatism were well-constrained by previous studies. Even though the sources of Strato-volcanoes and monogenetic vents were briefly explained, extremely young basalts (1.22 - 0.094 Ka) situated in northernmost part of Cappadocian Region and erupted between the two extentional faults, are not deeply investigated. Karaburna and Gülşehir lavas (1.22, 0.094 Ka, respectively, Dogan, 2011) are considered as a part of the Central Anatolian Volcanic Province, with extremely young ages, generated either at the final or after the final stage of the Cappadocian systems. These lavas have similar LIL and HFS elements patterns with each other, however, Karaburna samples are more enriched in HFS elements. These basalts also display approximately similar trends in LIL elements ( except Rb) and reflect HFS depletion relative to the OIB signature, moreover, HFS are more enriched compared to the Hasandag basaltic rocks, all these features suggesting, basaltic rocks are originated from the modified mantle source. Karaburna and Gülşehir basalts have low Nb/La (0.45-0.5 ; 0.35-0.42), Nb/Y( 0.33-.39; 0.27-0.44 Nb/Th (2.75-4.6; 1.26-1.68) and high Ba/Nb (22-32; 38-43) ratios suggesting the contributions from the crustal sources, moreoever, Gülşehir basaltic rocks differ from the Karaburna lavas with relatively low Nb/U ( 4.5-6.4) and high Ba/La ( 14.67-17.20) Th/La (0.22-0.27), whereas Karaburna samples are represented by low Ba/La (10.04-14.90) and Th/La (0.09-0.16) ratios, these geochemical features reveal that these differences are originated either from the different degrees of crustal involvement or change in the nature of the source in a short time interval. Of all the most recent basaltic products generated in central Anatolia are alkaline in nature, besides, the trace element content, multi-element patterns and HFS/LIL and

  17. Metal transports and enrichments in iron depositions hosted in basaltic rocks. II: Metal rich fluids and Fe origin

    Science.gov (United States)

    Zhang, Ronghua; Zhang, Xuetong; Hu, Shumin

    2015-12-01

    This study focuses on revealing the mechanism of metal transport, enrichment and Fe origin of iron deposition during water basalt interactions occurred in basaltic rocks. Observations of the iron deposits (anhydrite-magnetite-pyroxene type deposits) hosted in K-rich basaltic rocks in the Mesozoic volcanic area of the Middle-Lower Yangtze River valley, China, indicate that the mechanism of metal transport and enrichment for those deposits are significant objective to scientists, and the Fe origin problem is not well resolved. Here the metal transport, enrichment and iron origin have been investigated in high temperature experiments of water basaltic interactions. These deposits were accompanying a wide zone with metal alteration. The effects of hydrothermal alteration on major rock-forming element concentrations in basaltic rock were investigated by systematically comparing the chemical compositions of altered rocks with those of fresh rocks. In the deposits, these metals are distributed throughout altered rocks that exhibit vertical zoning from the deeper to the shallow. Then, combined with the investigations of the metal-alterations, we performed kinetic experiments of water-basaltic rock interactions using flow-through reactors in open systems at temperatures from 20 °C to 550 °C, 23-34 MPa. Release rates for the rock-forming elements from the rocks have been measured. Experiments provide the release rates for various elements at a large temperature range, and indicate that the dissolution rates (release rates) for various elements vary with temperature. Si, Al, and K have high release rates at temperatures from 300 °C to 500 °C; the maximum release rates (RMX) for Si are reached at temperatures from 300 °C to 400 °C. The RMXs for Ca, Mg, and Fe are at low temperatures from 20 °C to 300 °C. Results demonstrate that Fe is not released from 400 °C to 550 °C, and indicate that when deep circling fluids passed through basaltic rocks, Fe was not mobile, and

  18. Plume-stagnant slab-lithosphere interactions: Origin of the late Cenozoic intra-plate basalts on the East Eurasia margin

    Science.gov (United States)

    Kimura, Jun-Ichi; Sakuyama, Tetsuya; Miyazaki, Takashi; Vaglarov, Bogdan S.; Fukao, Yoshio; Stern, Robert J.

    2018-02-01

    Intra-plate basalts of 35-0 Ma in East Eurasia formed in a broad backarc region above the stagnant Pacific Plate slab in the mantle transition zone. These basalts show regional-scale variations in Nd-Hf isotopes. The basalts with the most radiogenic Nd-Hf center on the Shandong Peninsula with intermediate Nd-Hf at Hainan and Datong. The least radiogenic basalts occur in the perimeters underlain by the thick continental lithosphere. Shandong basalts possess isotopic signatures of the young igneous oceanic crust of the subducted Pacific Plate. Hainan and Datong basalts have isotopic signatures of recycled subduction materials with billions of years of storage in the mantle. The perimeter basalts have isotopic signatures similar to pyroxenite xenoliths from the subcontinental lithospheric mantle beneath East Eurasia. Hainan basalts exhibit the highest mantle potential temperature (Tp), while the Shandong basalts have the lowest Tp. We infer that a deep high-Tp plume interacted with the subducted Pacific Plate slab in the mantle transition zone to form a local low-Tp plume by entraining colder igneous oceanic lithosphere. We infer that the subducted Izanagi Plate slab, once a part of the Pacific Plate mosaic, broke off from the Pacific Plate slab at 35 Ma to sink into the lower mantle. The sinking Izanagi slab triggered the plume that interacted with the stagnant Pacific slab and caused subcontinental lithospheric melting. This coincided with formation of the western Pacific backarc marginal basins due to Pacific Plate slab rollback and stagnation.

  19. Chopped basalt fibres: A new perspective in reinforcing poly(lactic acid to produce injection moulded engineering composites from renewable and natural resources

    Directory of Open Access Journals (Sweden)

    P. Tamas

    2013-02-01

    Full Text Available This paper focuses on the reinforcing of Poly(lactic acid with chopped basalt fibres by using silane treated and untreated basalt fibres. Composite materials with 5–10–15–20–30–40 wt% basalt fibre contents were prepared from silane sized basalt fibres using extrusion, and injection moulding, while composites with 5–10–15 wt% basalt fibre contents were also prepared by using untreated basalt fibres as control. The properties of the injection moulded composites were extensively examined by using quasi-static (tensile, three-point bending and dynamic mechanical tests (notched and unnotched Charpy impact tests, dynamic mechanical analysis (DMA, differential scanning calorimetry (DSC, heat deflection temperature (HDT analysis, dimensional stability test, as well as melt flow index (MFI analysis and scanning electron microscopic (SEM observations. It was found that silane treated chopped basalt fibres are much more effective in reinforcing Poly(lactic acid than natural fibres; although basalt fibres are not biodegradable but they are still considered as natural (can be found in nature in the form of volcanic rocks and biologically inert. It is demonstrated in this paper that by using basalt fibre reinforcement, a renewable and natural resource based composite can be produced by injection moulding with excellent mechanical properties suitable even for engineering applications. Finally it was shown that by using adequate drying of the materials, composites with higher mechanical properties can be achieved compared to literature data.

  20. Geochemical and petrological considerations about the basalts of upper aluminium in the Fildes Peninsula. (Rei George), Antartica

    International Nuclear Information System (INIS)

    Machado, A.; Fernandes de Lima, E.; Chemale, F.

    1998-01-01

    Petrographic, geochemical and petrological studies of lower Tertiary basaltic rocks from Fildes Peninsula in Antarctica were made to characterize their source and magmatic evolution. These basaltic rocks have porphyritic, glomeroporphyritic, intergranular and intersertal textures. The phenocrysts are of plagioclase (An), augite, pigeonite and Ti-magnetite. These basaltic rocks have AL O from 16 to 22%, Ni from 6 to 88 ppm, Co from 24 to 33 ppm and Cr from 54 to 123 ppm. Enrichment of Rb. Ba, Sr and LREE with respect to HREE is observed as relative depleted in HFSE is detected. The mass balance realized to understand the evolution of liquid that gave source the different basaltic rocks. Showed that the extracted mineral fractions were 76% of plagioclase, 2% of clinopiroxene and 21% of olivine. The intermediate volcanic rocks of Fildes Peninsula can be explained by cristalization fractionation of a basic liquid. The isotopic dates showed initial rations of Sr/Sr <0,704 and positive values of Nd epsilon. These results are strong support a mantelic source for basaltic rocks of Fildes Peninsula. On basis of geochemical, petrological and isotopic characteristics is possible concluded that these rocks were formed in an island are environment with parcial melting of mantle wedge. (author)

  1. Effect of Chopped Basalt Fibers on the Mechanical Properties and Microstructure of High Performance Fiber Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Tehmina Ayub

    2014-01-01

    Full Text Available This paper presents the mechanical properties and the microstructure of the high performance fiber reinforced concrete (HPFRC containing up to 3% volume fraction of chopped Basalt fibers. Three types of the concrete were prepared, out of which, the first type was prepared by utilizing 100% cement content. The other two types of the concrete were prepared by replacing 10% cement content with silica fume and the locally produced metakaolin. Using each concrete type, four mixes were prepared in which Basalt fibers were added in the range of 0–3%; that is, total twelve mixes of the HPFRC concrete were prepared. From each of the twelve concrete mixes, total twelve specimens were cast to determine the mechanical properties of the HPFRC including compressive strength (cube and cylinder, splitting tensile strength, and the flexural strength. In this way, a total of 108 specimens were cast and tested in this study. Test results showed that the addition of the Basalt fibers significantly increased the tensile splitting strength and the flexural strength of the HPFRC, while there was slight improvement in the compressive strength with the addition of Basalt fibers. The microstructure of HPFRC was examined to determine the interfacial transition zone (ITZ between the aggregates and the paste by using field emission scanning electron microscope (FESEM, which showed the improvement of the ITZ due to the addition of the Basalt fibers.

  2. Annotated bibliography of the geology of the Columbia Plateau (Columbia River Basalt) and adjacent areas of Oregon

    International Nuclear Information System (INIS)

    Bela, J.

    1979-01-01

    This bibliography containing approximately 2000 entries was prepared by the Oregon Department of Geology and Mineral Industries under Subcontract SA-913 with Rockwell Hanford Operations' Basalt Waste Isolation Program. The objective of the Basalt Waste Isolation Program is to determine the feasibility of storing nuclear waste within the Columbia River Basalt Group. Under the geologic portion of this program, the stratigraphic, structural, tectonic, seismic, and hydrologic aspects of the Columbia Plateau are being examined. Other aspects of the Basalt Waste Isolation Program are concerned with systems integration, engineered barriers, engineering testing, and construction of a near-surface test facility. The area covered in this bibliography comprises that area north of 43 0 30' latitude and east of the Willamette Meridian, which is located just west of Portland. The bibliographic entries are presented in two forms. The first is an alphabetized listing of all articles dealing with the geology of the Columbia Plateau (Columbia River Basalt) and adjacent areas of Oregon. The second form consists of an alphabetized listing of the entries subdivided under fourteen categories

  3. Annotated bibliography of the geology of the Columbia Plateau (Columbia River Basalt) and adjacent areas of Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Bela, J.

    1979-01-01

    This bibliography containing approximately 2000 entries was prepared by the Oregon Department of Geology and Mineral Industries under Subcontract SA-913 with Rockwell Hanford Operations' Basalt Waste Isolation Program. The objective of the Basalt Waste Isolation Program is to determine the feasibility of storing nuclear waste within the Columbia River Basalt Group. Under the geologic portion of this program, the stratigraphic, structural, tectonic, seismic, and hydrologic aspects of the Columbia Plateau are being examined. Other aspects of the Basalt Waste Isolation Program are concerned with systems integration, engineered barriers, engineering testing, and construction of a near-surface test facility. The area covered in this bibliography comprises that area north of 43/sup 0/30' latitude and east of the Willamette Meridian, which is located just west of Portland. The bibliographic entries are presented in two forms. The first is an alphabetized listing of all articles dealing with the geology of the Columbia Plateau (Columbia River Basalt) and adjacent areas of Oregon. The second form consists of an alphabetized listing of the entries subdivided under fourteen categories. (RWR)

  4. Physical Volcanological and Petrogenetic Implications of Intra-lava Flow Geochemical Heterogeneity in the Columbia River Flood Basalt Province, USA.

    Science.gov (United States)

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

    2007-12-01

    Continental flood basalt lava flows are widely assumed to represent compositionally uniform and rapidly erupted products of large well-mixed magma reservoirs. However, this study presents new data to illustrate systematic element and isotope variations within the flow field formed by an individual flood basalt eruption, both vertically within each sheet lobe and laterally between the constituent lobes. Such variation is significant in chemostratigraphic correlation of flood basalt lava units, in identifying source variability during one eruption, and in petrogenetic modeling. We investigate the extent and cause of compositional variation through tracing lava sheet lobes in a 2,660 cubic kilometer pahoehoe flow field formed during a single eruption in the Columbia River Basalt Province, USA. This is based on features related to emplacement by the inflation mechanism. This method of emplacement is supported by small but statistically significant and systematic major and trace element variation e.g. MgO 3.09- 4.55 wt%, Ni 17.5-25.6 ppm, indicative of fractional crystallisation. Re-Os isotopes indicate progressive crustal contamination of the magma over the timescale of a single flood basalt eruption. By establishing this physical volcanological framework, we determine a temporal link with the supply of lava from the vent(s) and apply it to investigate sequential magmatic evolution during the timescale of one eruption.

  5. Effective Carbon Dioxide Photoreduction over Metals (Fe-, Co-, Ni-, and Cu- Incorporated TiO2/Basalt Fiber Films

    Directory of Open Access Journals (Sweden)

    Jeong Yeon Do

    2016-01-01

    Full Text Available Mineralogical basalt fibers as a complementary adsorbent were introduced to improve the adsorption of CO2 over the surfaces of photocatalysts. TiO2 photocatalysts (M-TiO2 incorporated with 5.0 mol.% 3d-transition metals (Fe, Co, Ni, and Cu were prepared using a solvothermal method and mixed with basalt fibers for applications to CO2 photoreduction. The resulting 5.0 mol.% M-TiO2 powders were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectroscopy, photoluminescence, Brunauer, Emmett, and Teller surface area, and CO2-temperature-programmed desorption. A paste composed of two materials was coated and fixed on a Pyrex plate by a thermal treatment. The 5.0 mol.% M-TiO2/basalt fiber films increased the adsorption of CO2 significantly, indicating superior photocatalytic behavior compared to pure TiO2 and basalt fiber films, and produced 158~360 μmol gcat-1 L−1 CH4 gases after an 8 h reaction. In particular, the best performance was observed over the 5.0 mol.% Co-TiO2/basalt fiber film. These results were attributed to the effective CO2 gas adsorption and inhibition of photogenerated electron-hole pair recombination.

  6. Secondary Sulfate Mineralization and Basaltic Chemistry of Craters of the Moon National Monument, Idaho: Potential Martian Analog

    Energy Technology Data Exchange (ETDEWEB)

    C. Doc Richardson; Nancy W. Hinman; Lindsay J. McHenry; J. Michelle Kotler; Jill R. Scott

    2012-05-01

    Secondary deposits associated with the basaltic caves of Craters of the Moon National Monument (COM) in southern Idaho were examined using X-ray powder diffraction, X-ray fluorescence spectrometry, Fourier transform infrared spectrometry, and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The secondary mineral assemblages are dominated by Na-sulfate minerals (thenardite, mirabilite) with a small fraction of the deposits containing minor concentrations of Na-carbonate minerals. The assemblages are found as white, efflorescent deposits in small cavities along the cave walls and ceilings and as localized mounds on the cave floors. Formation of the deposits is likely due to direct and indirect physiochemical leaching of meteoritic water through the overlying basalts. Whole rock data from the overlying basaltic flows are characterized by their extremely high iron concentrations, making them good analogs for martian basalts. Understanding the physiochemical pathways leading to secondary mineralization at COM is also important because lava tubes and basaltic caves are present on Mars. The ability of FTICR-MS to consistently and accurately identify mineral species within these heterogeneous mineral assemblages proves its validity as a valuable technique for the direct fingerprinting of mineral species by deductive reasoning or by comparison with reference spectra.

  7. Petrographical, geochemical and petrological study of the xenoliths associating the basalt of (Southwest, Syria)

    International Nuclear Information System (INIS)

    Safarjalani, A.; Nasir, S.

    1998-01-01

    Alkali basalt spread northeast part of Shamah volcanic field (Southwest of Syria) belonging to the Neogene and Quaternary ages, which are coexisted with a great quantity of mafic and ultramafic xenoliths and megacrysts. Field observations and data of geochemical and petrographical studies results, for xenoliths coexisted with alkali basalt speared over the northwest part of the arabian plate (Syria) indicate availability of a proper environment where various kinds of xenoliths of lower crustal and upper mantle were formed, this indicates that these xenoliths have been formed under different thermo barometric conditions. The study of available mineral para genesis and geothermobarometrics on coexisting minerals suggests equilibration conditions, ranging between 6-8 kba for pressure and 850-920 Centigrade for temperature, and that is for xenoliths of gabbroic nature formed in the lower crustal between 20-27 km depth. With regard to the formation conditions of the xenoliths formed in the upper mantle (Pyroxenite and Lherzolite); they rang between 13.5 - 14.5 kba for pressure and 950-1060 Centigrade for temperature. (Author)

  8. Evaluation of alternative spent fuel waste package concepts for a repository in Basalt

    International Nuclear Information System (INIS)

    Hall, G.V.B.; Nair, B.R.

    1986-01-01

    The United States government has established a program for the disposal of spent nuclear fuel and high-level radioactive waste. The Nuclear Waste Policy Act (NWPA) of 1982 requires the first nuclear waste repository to begin receiving high-level radioactive waste in 1998. One of the potentially acceptable sites currently being evaluated is the Hanford Site in the Pasco Basin in the state of Washington where the host rock is basalt. Under the direction of the United States Department of Energy (DOE), Rockwell International's Rockwell Hanford Operations (RHO) has initiated the Basalt Waste Isolation Project (BWIP). The BWIP must design waste packages for emplacement in the repository. As part of the BWIP waste package development program, several alternative designs were considered for the disposal of spent nuclear fuel. This paper describes the concepts that were evaluated, the criteria that was developed for judging their relative merits, and the methodology that was employed. The results of the evaluation show that a Pipe-In-Tunnel design, which uses a long carbon steel pipe for the containment barrier for multiple packages of consolidated spent fuel, has the highest rating. Other designs which had high ratings are also discussed

  9. 182W evidence from flood basalt lavas for the long-term survival of primordial mantle

    Science.gov (United States)

    Rizo Garza, H. L.; Walker, R. J.; Carlson, R.; Horan, M. F.; Mukhopadhyay, S.; Francis, D.; Jackson, M. G.

    2016-12-01

    How much of the chemical heterogeneity present in mantle today dates to processes that occurred during Earth's planetary formation stage remains an unanswered question. Geochemical observations obtained from short-lived radiogenic isotope systems, however, provide important insights. Tungsten isotope data for flood basalt lavas from two large igneous provinces, the North Atlantic Igneous Province ( 60 Ma) and the Ontong Java Plateau ( 120 Ma), show well resolved 182W excesses, compared with terrestrial standards that are presumed to be representative of the present bulk mantle. These W isotope results, thus, indicate that one or more mantle domains formed very early in Earth history and have been preserved well into the Phanerozoic eon. The flood basalts from Baffin Bay contain among the highest 3He/4He ratios ever measured, as well as Pb and 143Nd isotopic compositions, and D/H ratios consistent with a chemically primitive, un-degassed mantle source. Ontong Java is the Earth's largest known volcanic province and shares chemical and isotopic similarities with the Baffin Bay lavas, indicative of a similarly primitive mantle source. The 182W-enriched nature of the mantle sources of rocks from both locations indicates that their primitive characteristics were likely isolated in a deep mantle reservoir within the first 50 Ma of Solar System history. The correlation between large low seismic shear velocity provinces (LLSVPs) and the distribution of reconstructed eruption sites of these large igneous provinces makes the LLSVPs possible candidate domains for the required primitive and un-degassed reservoirs.

  10. Basalt Waste Isolation Program. Quarterly report, April 1, 1979-June 30, 1979

    International Nuclear Information System (INIS)

    Deju, R.A.

    1979-07-01

    During the quarter, progress was made in all areas of the Basalt Waste Isolation Program. In the Geosciences, Hydrology, and Engineered Barriers areas, work continued on schedule aimed at being able to make a site selection decision in 1981, as scheduled. Emphasis continued to be placed on geologic mapping studies, on hydrologic data gathering, and on definition of waste/basalt interactions and needed engineered barriers. Progress at the end of the quarter on the Near-Surface Test Facility was approximately on schedule and the rate of work was accelerating to better than scheduled due to some equipment improvements and tunnel design modifications. In the Engineering Testing area, design work, test planning, and fabrication of heaters and auxiliary equipment continued on schedule. In the Repository area, an Architect/Engineer Evaluation Board was formally designed by the US Department of Energy-Headquarters during October 1978. The evaluation board will select an architect/engineer for repository conceptual design with an option for follow-on Title I, Title II, and Title III engineering services. Selection will be completed by October 1979. Questionnaire information was received from a number of interested architect/engineer firms by the US Department of Energy-Richland Operations Office and has been evaluated. Onsite visits with the qualified firms were completed during April 1979. In addition, repository preconceptual design studies continued on schedule with emphasis on compilation of repository functional design criteria by July 1979, and the repository preconceptual design report in September 1979

  11. Chemical trends in the Ice Springs basalt, Black Rock Desert, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, W.C.; Nash, W.P.

    1980-06-01

    The Holocene Ice Springs volcanic field of west-central Utah consists of 0.53 km/sup 3/ of tholeiitic basalts erupted as a sequence of nested cinder cones and associated lava flows. Whole rock x-ray fluorescence and atomic absorption analysis of ninety-six samples of known relative age document statistically significant inter- and intra-eruption chemical variations. Elemental trends include increases in Ti, Fe, Ca, P, and Sr and decreases in Si, K, Rb, Ni, Cr, and Zr with decreasing age. Microprobe analyses of microphenocrysts of olivine, plagioclase, and Fe-Ti oxides and of groundmass olivine, plagioclase, and clinopyroxene indicate limited chemical variation between mineral assemblages of the eruptive events. Petrographic analyses have identified the presence of minor amounts of silicic xenoliths, orthopyroxene megacrysts, and plagioclase xenocrysts. Potassium-argon determinations establish the existence of excess argon in the basaltic cinder (30.05 x 10/sup -12/ moles/gm) and in distal lava flows (8.29 x 10/sup -12/ moles/gm) which suggest apparent ages of 16 and 4.3 million years respectively. Strontium isotopic data (Puskar and Condie, 1973) show systematic variations from oldest eruptions (87Sr/86Sr=0.7052) to youngest eruptions (87Sr/86Sr=0.7059).

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

    Science.gov (United States)

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

    1998-10-01

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

  13. Textures of Pyroclasts From Explosive Basaltic Eruptions at Soputan Volcano, Indonesia

    Science.gov (United States)

    Wright, H. M. N.; Kunrat, S. L.; Pallister, J. S.

    2016-12-01

    Soputan volcano, Indonesia has produced relatively frequent explosive eruptions; over the past 35 years, the average repose interval is just two years. Eruptions over that interval have included effusion of basaltic lava domes and flows, production of high-altitude (up to 13 km) explosive ash columns, and production of pyroclastic flows with up to 5.5 km runout distances. The ascent history and degassing structure is explored here using textural observations of pyroclasts within pyroclastic flows, ash grains from tephra fall, and lava flow samples. Lava flows and pyroclastic flow deposits are highly crystalline, with 40-50% phenocrysts and up to 35% microlites, suggesting a highly viscous rheology of basaltic lava (50-51% SiO2). Vesicularities are exceptionally low; clasts in pyroclastic flow deposits have vesicularities ranging from 12-30%. Pyroclasts in pyroclastic flow deposits are highly spherical in shape across a broad grain size distribution. In cross section, these clasts display moderate alignment of phenocrysts parallel to the clast margins, suggesting relaxation of the melt after fragmentation into spherical shapes and not abrasion or milling of clasts during transport. This observation lies in apparent contrast to high inferred viscosities based on crystallinity and vesicularity measurements.

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  15. Changing compositions in the Iceland plume; Isotopic and elemental constraints from the Paleogene Faroe flood basalts

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin

    2011-01-01

    Elemental and Sr, Nd, Hf and high precision Pb isotopic data are presented from 59 low-Ti and high-Ti lavas from the syn-break up part of the Faroe Flood Basalt Province. The depleted MORB-like low-Ti lavas erupted in the rift zone between the Faroe Islands and central East Greenland around...... the time of break up of the North Atlantic have isotopic end-member compositions different from the depleted Iceland lavas. We suggest that the main low-Ti mantle component is NAEM (North Atlantic End-Member (Ellam and Stuart, 2000, J. Petrol. 41, 919) and that the 207Pb/204Pb value of the component should...... be 15.35 and eHf=+16.5. NAEM is the main depleted component in the early Iceland plume. This is supported by high mantle potential temperatures (up to 1550 °C) calculated for the source of the low-Ti basalts. The unique mantle isotopic composition of NAEM with low 206Pb/204Pb (17.5) and ¿7/4Pb (-3...

  16. Plutonium speciation in selected basalt, granite, shale, and tuff ground waters

    International Nuclear Information System (INIS)

    Cleveland, J.M.; Nash, K.L.; Rees, T.F.

    1983-01-01

    The speciation of added plutonium was determined in ground waters of widely varying composition from four rock types: basalt, granite, shale, and tuff. Plutonium was soluble in the basalt water, which contained a high fluoride ion concentration, probably as a result of its stabilization in solution as fluorocomplexes, primarily of plutonium (IV); it was insoluble, however, in the shale ground water, which contained the highest concentration of sulfate ion. Results were intermediate in the granite and tuff ground waters. In synthetic waters containing significant concentrations of both sulfate and fluoride, the effects were smaller and less predictable. Dissolved oxygen, ionic strength, carbonate ion concentration, and pH had little effect on plutonium speciation in the ranges encountered in this study. However, other ionic species not involved in this study may also influence plutonium speciation. The results have potential significance in establishing site-selection criteria for radioactive waste repositories. All other factors being equal, host rocks whose associated waters contain low concentrations of free fluoride ion should be preferable for the location of waste repositories

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

    Science.gov (United States)

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

    2017-09-01

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

  18. Bunburra Rockhole: Exploring the Geology of a New Differentiated Basaltic Asteroid

    Science.gov (United States)

    Benedix, G.K.; Bland, P. A.; Friedrich, J. M.; Mittlefehldt, D.; Sanborn, M. E.; Yin, Q.-Z.; Greenwood, R. C; Franchi, L. A.; Bevan, A. W. R.; Towner, M. C.; hide

    2014-01-01

    Bunburra Rockhole (BR) is the first recovered meteorite of the Desert Fireball Network. It was initially classified as a basaltic eucrite, based on texture, mineralogy, and mineral chemistry but subsequent O isotopic analyses showed that BR's composition lies significantly far away from the HED group of meteorites. This suggested that BR was not a piece of the HED parent body (4 Vesta), but other explanations could also account for the observed oxygen signatures. Possible scenarios include contamination by components from other bodies (chondrites or other achondrites) or that 4 Vesta may not be as equilibrated as hypothesized. After examining multiple pieces with different instruments (CT scans and x-ray maps), no obvious evidence of contamination was found. If BR is not from Vesta, a conundrum exists as no unusual features were found in mineral and bulk trace element chemistry as exist for other anomalous basaltic achondrites such as Ibitira or Asuka 881394. These meteorites have distinct petrological and geochemical characteristics, in addition to their anomalous O isotope compositions, that set them apart from eucrites. Thus, early results provided a somewhat ambiguous picture of BR's petrogenesis and parentage. To clarify the nature of the relationship, if any, between BR and eucrites, we have performed a correlated stable isotope and bulk chemical study of several lithologic fragments.

  19. A survey of Li isotope content in freshwater on a basaltic island of the Galapagos Archipelago

    Science.gov (United States)

    Larsen, W.; Liu, X. M.; Riveros-Iregui, D. A.

    2017-12-01

    Li isotopes in continental surface water fractionate during chemical weathering processes, but their utility as a global paleoenvironmental proxy remains in question. Here we investigate factors controlling Li isotope fractionation in groundwater and streams that drain a single lithology on a basaltic island. Isla San Cristobál, Ecuador has no evidence of hydrothermal activity and is the only island in the Galápagos Archipelago that has permanent sources of fresh water. Multiple perennial streams are located on the windward side of the island, many of which are fed by groundwater springs. We investigate the hydrologic control on Li isotopes in groundwater and streams on San Cristobál to affirm the applicability of Li isotopes as tracers of groundwater residence times and chemical weathering intensity. Water samples were taken from groundwater springs and streams throughout 5 different catchments for Li isotopic analysis. Preliminary analyses show that high elevation (>500m) groundwater springs have an average pH and TDS much closer to that of rainwater than low elevation (200-300m) groundwater springs. This points to a comparatively longer groundwater residence time for low elevation springs with larger Li isotope fractionation. Observing the evolution of the dissolved Li isotopic signal from groundwater through streams to the ocean will provide a valuable comparison to studies conducted on catchments draining similar basaltic lithologies.

  20. Manufacture of Green-Composite Sandwich Structures with Basalt Fiber and Bioepoxy Resin

    Directory of Open Access Journals (Sweden)

    J. P. Torres

    2013-01-01

    Full Text Available Nowadays, there is a growing interest for the use and development of materials synthesized from renewable sources in the polymer composites manufacturing industry; this applies for both matrix and reinforcement components. In the present research, a novel basalt fibre reinforced (BFR bioepoxy green composite is proposed as an environmentally friendly alternative to traditional petroleum-derived composites. In addition, this material system was combined with cork as core material for the fabrication of fibre composite sandwich structures. Mechanical properties of both skin and core materials were assessed through flexural and tensile tests. Finite element (FEM simulations for the mechanical stress analysis of the sandwich material were carried out, and a maximum allowable shear stress for material failure under bending loads was established. Permeability measurements of the basalt fabrics were carried out in order to perform numerical simulations of liquid composite moulding (LCM processes on the PAM-RTM software. The proposed green-composite sandwich material was used for the fabrication of a longboard as a case study for a sports equipment application. Numerical simulations of the mould filling stage allowed the determination of an optimal mould filling strategy. Finally, the load-bearing capacity of the board was studied by means of FEM simulations, and the presented design proved to be acceptable for service.

  1. Status report on studies to assess the feasibility of storing nuclear waste in Columbia Plateau basalts

    International Nuclear Information System (INIS)

    Deju, R.A.; Evans, G.C.

    1979-11-01

    The Basalt Waste Isolation Project, is part of the National Waste Terminal Storage Program. The program, as presently structured, is aimed at assessing the feasibility and providing the technology needed to design and construct a repository for storage of commercial radioactive waste in the extensive basalts beneath the Hanford Site of the United States Department of Energy. The program is presently in the research and development phase to assess feasibility. Geologic site selection studies are to be completed in September 1981, to allow a feasibility decision at that time, where-upon if feasibility is proven and the United States Department of Energy goes forward with the project, we would move into the licensing phase of the project. Ultimately, it would be up to the United States Nuclear Regulatory Commission to grant a construction license and, later on, an operating license. During the research and development phase, the program includes seven areas of study; namely, geosciences, hydrology multiple engineered barriers, test facility design and construction, engineering testing, systems integration, and preliminary repository engineering design. The progress made to date in each of these areas is detailed

  2. Surface modification and characterization of basalt fibers as potential reinforcement of concretes

    Science.gov (United States)

    Iorio, M.; Santarelli, M. L.; González-Gaitano, G.; González-Benito, J.

    2018-01-01

    Basalt fibers were surface treated with silane coupling agents as a method to enhance the adhesion and durability of fiber-matrix interfaces in concrete based composite materials. In particular, this work has been focused on the study of basalt fibers chemical coatings with aminosilanes and their subsequent characterization. Surface treatments were carried out after removing the original sizing applied by manufacturer and pretreating them with an activation process of surface silanol regeneration. Different samples were considered to make convenient comparisons: as received fibers (commercial), calcinated fibers (without commercial sizing), activated samples (calcinated fibers subjected to an acid process for hydroxyl regeneration), and silanized fibers with γ-aminopropiltriethoxysilane, γ-aminopropilmethyldiethoxysilane and a mixture of 50% by weight of both silanes. A deep characterization was carried out in terms of structure using X-ray diffraction, XRD, and Fourier transform infrared spectroscopy, FTIR, thermal properties by thermogravimetric analysis, TGA, coupled with single differential thermal analysis, SDTA, and morphology by scanning electron microscopy, SEM, and atomic force microscopy, AFM.

  3. Floral changes across the Triassic/Jurassic boundary linked to flood basalt volcanism

    Science.gov (United States)

    van de Schootbrugge, B.; Quan, T. M.; Lindström, S.; Püttmann, W.; Heunisch, C.; Pross, J.; Fiebig, J.; Petschick, R.; Röhling, H.-G.; Richoz, S.; Rosenthal, Y.; Falkowski, P. G.

    2009-08-01

    One of the five largest mass extinctions of the past 600million years occurred at the boundary of the Triassic and Jurassic periods, 201.6million years ago. The loss of marine biodiversity at the time has been linked to extreme greenhouse warming, triggered by the release of carbon dioxide from flood basalt volcanism in the central Atlantic Ocean. In contrast, the biotic turnover in terrestrial ecosystems is not well understood, and cannot be readily reconciled with the effects of massive volcanism. Here we present pollen, spore and geochemical analyses across the Triassic/Jurassic boundary from three drill cores from Germany and Sweden. We show that gymnosperm forests in northwest Europe were transiently replaced by fern and fern-associated vegetation, a pioneer assemblage commonly found in disturbed ecosystems. The Triassic/Jurassic boundary is also marked by an enrichment of polycyclic aromatic hydrocarbons, which, in the absence of charcoal peaks, we interpret as an indication of incomplete combustion of organic matter by ascending flood basalt lava. We conclude that the terrestrial vegetation shift is so severe and wide ranging that it is unlikely to have been triggered by greenhouse warming alone. Instead, we suggest that the release of pollutants such as sulphur dioxide and toxic compounds such as the polycyclic aromatic hydrocarbons may have contributed to the extinction.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  5. Kinetics and physico-chemical properties of alkali activated blast-furnace slag/basalt pastes

    Directory of Open Access Journals (Sweden)

    H. El Didamony

    2012-12-01

    Full Text Available Granulated blast-furnace slag (GBFS is a by-product of the metallurgical industry and consists mainly of lime and calcium–magnesium aluminosilicates that defined as the glassy granular material formed by rapid cooling of molten slag with excess water resulting in an amorphous structure. Alkali-activated slag (AAS binders have taken a great interest from researchers due to its manufacturing process which has important benefits from the point of view of the lower energy requirements and lower emission of greenhouse gases with respect to the manufacturing of Portland cement. In this study, GBFS was replaced by 20, 40 and 60 wt.% of basalt activated by 6 wt.% of alkali mixture composed of 1:1 sodium hydroxide (SH and liquid sodium silicate (LSS mixed with sea water and cured in 100% relative humidity up to 90 days. The physic-chemical parameters were studied by determination of setting time, combined water content, bulk density and compressive strength. As the amount of basalt increases the setting time as well as compressive strength decreases while the bulk density increases. The compressive strength values of dried pastes are greater than those of saturated pastes. The hydrated products are identified by TGA/DTG analysis, IR spectroscopy and scanning electron microscopy (SEM.

  6. Borehole plugging of man-made accesses to a basalt repository: a preliminary study

    International Nuclear Information System (INIS)

    Taylor, C.L.; Anttonen, G.J.; O'Rourke, J.E.; Niccum, M.R.

    1979-09-01

    This report describes the status of work currently in progress for the Basalt Borehole Plugging Program (BBPP). The primary objectives of the BBPP outlined in this report have been met during this first phase of work. These objectives included: (1) the preparation of a preliminary list of candidate plug materials; (2) a description of available machinery capable of placing candidate plug materials; and (3) the development of physical and geochemical testing programs to help evaluate the chemical stability and physical properties of candidate plug materials. The most significant finding from work to date is that given reasonable regulatory criteria, nothing has been identified which would prevent design of a plug system to seal manmade openings leading to a nuclear waste repository in Columbia River basalt for significantly long periods of time (on the order of thousands of years). Work accomplished to date indicates that this plug system can be designed using both natural and manufactured materials and can be emplaced with existing placement machinery and modifications of that machinery. The objectives of Task II are to conduct laboratory tests to evaluate the suitability of preferred candidate materials for plugging boreholes in the proposed repository, select plug system(s), initiate preconceptual machinery design for the placement of materials in plug system(s), and prepare a preliminary Task II report. As with Task I project organization, Task II is divided into subtasks that are identified by written subtask work summaries

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

    International Nuclear Information System (INIS)

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

    1993-02-01

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

  8. Porosity and hydraulic conductivity estimation of the basaltic aquifer in Southern Syria by using nuclear and electrical well logging techniques

    Science.gov (United States)

    Asfahani, Jamal

    2017-08-01

    An alternative approach using nuclear neutron-porosity and electrical resistivity well logging of long (64 inch) and short (16 inch) normal techniques is proposed to estimate the porosity and the hydraulic conductivity ( K) of the basaltic aquifers in Southern Syria. This method is applied on the available logs of Kodana well in Southern Syria. It has been found that the obtained K value by applying this technique seems to be reasonable and comparable with the hydraulic conductivity value of 3.09 m/day obtained by the pumping test carried out at Kodana well. The proposed alternative well logging methodology seems as promising and could be practiced in the basaltic environments for the estimation of hydraulic conductivity parameter. However, more detailed researches are still required to make this proposed technique very performed in basaltic environments.

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

    International Nuclear Information System (INIS)

    Lebeau, M.J.

    1988-01-01

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

  10. Statement of John H. Anttonen, Project Manager, Basalt Waste Isolation Project, Richland Operations Office, Department of Energy

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    My name is John Anttonen and I am the Project Manager for the Basalt Waste Isolation Project (BWIP) at the Department of Energy Richland Operation Office. The responsibilities of may office are to manage the day-to-day activities of the site suitability investigations of the basalt formations at the Hanford Site, a Department complex that is involved in a variety of national missions, including defense materials production, nuclear energy research, and radioactive waste management. In may prepared comments today I would like to touch upon four specific subject areas relating to the BWIP program and then I would be happy to answer any questions you might have. The topics I will cover are: (1) historical aspects; (2) site specific technical issues and how they will be addressed during site characterization of the basalt site at Hanford; (3) current project status and; (4) institutional interaction. For clarity, I have attached several charts to my statement

  11. Olivine and melt inclusion chemical constraints on the source of intracontinental basalts from the eastern North China Craton: Discrimination of contributions from the subducted Pacific slab

    Science.gov (United States)

    Li, Hong-Yan; Xu, Yi-Gang; Ryan, Jeffrey G.; Huang, Xiao-Long; Ren, Zhong-Yuan; Guo, Hua; Ning, Zhen-Guo

    2016-04-01

    Contributions from fluid and melt inputs from the subducting Pacific slab to the chemical makeup of intraplate basalts erupted on the eastern Eurasian continent have long been suggested but have not thus far been geochemically constrained. To attempt to address this question, we have investigated Cenozoic basaltic rocks from the western Shandong and Bohai Bay Basin, eastern North China Craton (NCC), which preserve coherent relationships among the chemistries of their melt inclusions, their hosting olivines and their bulk rock compositions. Three groups of samples are distinguished: (1) high-Si and (2) moderate-Si basalts (tholeiites, alkali basalts and basanites) which were erupted at ∼23-20 Ma, and (3) low-Si basalts (nephelinites) which were erupted at <9 Ma. The high-Si basalts have lower alkalies, CaO and FeOT contents, lower trace element concentrations, lower La/Yb, Sm/Yb and Ce/Pb but higher Ba/Th ratios, and lower εNd and εHf values than the low-Si basalts. The olivines in the high-Si basalts have higher Ni and lower Mn and Ca at a given Fo value than those crystallizing from peridotite melts, and their corresponding melt inclusions have lower CaO contents than peridotite melts, suggesting a garnet pyroxenitic source. The magmatic olivines from low-Si basalts have lower Ni but higher Mn at a given Fo value than that of the high-Si basalts, suggesting more olivine in its source. The olivine-hosted melt inclusions of the low-Si basalts have major elemental signatures different from melts of normal peridotitic or garnet pyroxenitic mantle sources, pointing to their derivation from a carbonated mantle source consisting of peridotite and garnet pyroxenite. We propose a model involving the differential melting of a subduction-modified mantle source to account for the generation of these three suites of basalts. Asthenospheric mantle beneath the eastern NCC, which entrains garnet pyroxenite with an EM1 isotopic signature, was metasomatized by carbonatitic

  12. Preliminary data on mantle xenoliths from the Feldstein basalt (Thuringia, Germany)

    Science.gov (United States)

    Kukuła, Anna; Puziewicz, Jacek; Ntaflos, Theodoros; Matusiak-Małek, Magdalena; Milke, Ralf

    2014-05-01

    Feldstein is an isolated outcrop of columnar basaltic rock nearby Themar, located 60 km south-west of Erfurt (Thuringia, Germany). The Feldstein alkali basalt (ca. 16.3 Ma) belongs to the Heldburger Gangschar subset of the Central European Volcanic Province (Abratis et al. 2007). The Feldstein alkali basalt contains peridotitic xenoliths, which were the subject of our study. Two groups of spinel peridotite xenoliths occur in the Feldstein basalt. Group A spinel peridotite (2 xenoliths) is characterized by protogranular texture with typical grain size of 2 - 3 mm (max 8 mm). It consists of olivine (90.28 - 91.36 % Fo, 0.35 - 0.45 wt. % NiO), orthopyroxene (mg# 0.91 - 0.92, Al 0.09 - 0.18 a pfu), clinopyroxene (mg# 0.93 - 0.95, Al 0.06 - 0.21 a pfu) and spinel (cr# 0.20 - 0.41, mg# 0.66 - 0.78). The mg# and Al content in clinopyroxene are negatively correlated following the depletion trend after variable degrees of partial melting of the same source. One of the studied samples contains clinopyroxene that does not plot on the general depletion trend but has significantly higher Al (0.15 - 0.21 a pfu) for similar mg # 0.93 - 0.94 with clinopyroxenes from this trend. However the primitive mantle normalized clinopyroxene REE patterns (concave upwards with LaN/YbN=0.11) indicate that they are the residues after elevated degrees of partial melting. The most magnesian clinopyroxene that is Ca-rich and Al-poor has REE abundances, typical for strongly depleted spinel peridotites. It has concave upwards primitive mantle normalized pattern and LaN/YbN=0.61. A slight increase of LaN and CeN with inflection point at PrN has been observed as well. The group B spinel peridotites have protogranular texture (3-4 mm, max 7 mm grains) and some of them contain several melt pockets of basaltic composition. It consists of olivine (88.95 - 91.32 % Fo, 0.34 - 0.47 wt.% NiO), orthopyroxene (mg# 0.90 - 0.93, Al 0.04 - 0.16 apfu) and clinopyroxene (mg# 0.90 - 0.93, Al 0.10 - 0.20 a pfu). The

  13. Quaternary basaltic volcanism in the Golden Trout Volcanic Field, southern Sierra Nevada, California

    Science.gov (United States)

    Browne, Brandon L.; Becerra, Raul; Campbell, Colin; Saleen, Phillip; Wille, Frank R.

    2017-09-01

    The Golden Trout Volcanic Field (GTVF) produced the only Quaternary eruptions of mafic magma within the southern Sierra Nevada block. Approximately 38 × 106 m3 of basalt, trachy-basalt, basaltic trachy-andesite, and basaltic andesite (50.1-56.1% SiO2, 1.1-1.9% K2O, and 5.4-9.1% MgO) was erupted from four vents within a 10 km2 portion of the GTVF, which also includes rhyolite domes that are not considered in this study. The vents include, from oldest to youngest: Little Whitney Cone, South Fork Cone, Tunnel Cone, and unglaciated Groundhog Cone. Little Whitney Cone is a 120 m-high pile of olivine-CPX-phyric scoria produced during a Strombolian-style eruption overlying two columnar jointed lava flows. Tunnel Cone formed through a Hawaiian-style eruption along a 400 m-long north-south trending fissure that excavated at least three 25-65 m-wide craters. Crater walls up to 12 m high are composed of plagioclase-olivine-phyric spatter-fed flows that dip radially away from the crater center and crumble to form Tunnel Cone's steep unconsolidated flanks. South Fork Cone is a 170 m-high pile of plagioclase-olivine-phyric scoria that formed during Strombolian to violent Strombolian eruptions. South Fork Cone overlies the South Fork Cone lava, a 9.5 km-long flow ( 12 × 106 km3) that reached the Kern River Canyon to the west. Scoria and airfall deposits originating from South Fork Cone are located up to 2 km from the vent. Groundhog Cone is a 140 m-tall cinder and spatter cone breached on the north flank by a 13 × 106 m3 lava flow that partially buried the South Fork Cone lava and extends 7.5 km west to Kern River Canyon. Incompatible trace element concentrations and ratios show vent-specific trends but are unsystematic when plotted in terms of all mafic GTVF vents, implying that GTVF basalts were derived from a lithospheric mantle source and ascended through thick granitic Sierra Nevada crust as discrete batches that underwent different degrees of crustal contamination

  14. The source and longevity of sulfur in an Icelandic flood basalt eruption plume

    Science.gov (United States)

    Ilyinskaya, Evgenia; Edmonds, Marie; Mather, Tamsin; Schmidt, Anja; Hartley, Margaret; Oppenheimer, Clive; Pope, Francis; Donovan, Amy; Sigmarsson, Olgeir; Maclennan, John; Shorttle, Oliver; Francis, Peter; Bergsson, Baldur; Barsotti, Sara; Thordarson, Thorvaldur; Bali, Eniko; Keller, Nicole; Stefansson, Andri

    2015-04-01

    The Holuhraun fissure eruption (Bárðarbunga volcanic system, central Iceland) has been ongoing since 31 August 2014 and is now the largest in Europe since the 1783-84 Laki event. For the first time in the modern age we have the opportunity to study at first hand the environmental impact of a flood basalt fissure eruption (>1 km3 lava). Flood basalt eruptions are one of the most hazardous volcanic scenarios in Iceland and have had enormous societal and economic consequences across the northern hemisphere in the past. The Laki eruption caused the deaths of >20% of the Icelandic population by environmental pollution and famine and potentially also increased European levels of mortality through air pollution by sulphur-bearing gas and aerosol. A flood basalt eruption was included in the UK National Risk Register in 2012 as one of the highest priority risks. The gas emissions from Holuhraun have been sustained since its beginning, repeatedly causing severe air pollution in populated areas in Iceland. During 18-22 September, SO2 fluxes reached 45 kt/day, a rate of outgassing rarely observed during sustained eruptions, suggesting that the sulfur loading per kg of erupted magma exceeds both that of other recent eruptions in Iceland and perhaps also other historic basaltic eruptions globally. This raises key questions regarding the origin of these prodigious quantities of sulphur. A lack of understanding of the source of this sulfur, the conversion rates of SO2 gas into aerosol, the residence times of aerosol in the plume and the dependence of these on meteorological factors is limiting our confidence in the ability of atmospheric models to forecast gas and aerosol concentrations in the near- and far-field from Icelandic flood basalt eruptions. In 2015 our group is undertaking a project funded by UK NERC urgency scheme to investigate several aspects of the sulfur budget at Holuhraun using a novel and powerful approach involving simultaneous tracking of sulfur and

  15. The Origin of Basalt and Cause of Melting Beneath East Antarctica as Revealed by the Southernmost Volcanoes on Earth

    Science.gov (United States)

    Reindel, J. L.; Panter, K. S.; Smellie, J. L.; McIntosh, W. C.

    2017-12-01

    Mt. Early and Sheridan Bluff are two basaltic monogenetic volcanoes located at 87° South latitude at the head of the Scott Glacier. These Early Miocene volcanoes lie 800 km from any other volcano and 200 km inland from the shoulder of the West Antarctic Rift System (WARS), which is the foci of most Cenozoic alkaline volcanism in Antarctica. Preliminary 40Ar/39Ar dates suggest that Mt. Early is older than previously determined and closer in age to Sheridan Bluff ( 19 Ma). Petrography, mineral chemistry and whole rock major and trace element concentrations are used to characterize the basalts and to determine whether they are genetically related to mafic volcanism in the WARS. The basalts are porphyritic with phenocrysts of olivine (Fo 58-84%), plagioclase (An 48-67%) ± clinopyroxene (Wo 43-48%). Whole rock MgO range from 10 to 4 wt.% and have restricted SiO2 (48 to 50 wt.%) contents. The basalts vary from alkaline (up to 6 wt.% Ne-normative) to subalkaline (up to 6 wt.% Hy-normative). The alkaline basalts that occur at both Mt. Early and Sheridan Bluff are more strongly enriched in incompatible elements (La 33-49 ppm, Ba 270-484 ppm, Sr 712-1009 ppm), have LaN/YbN ratios >10 and show prominent Pb negative anomalies with only slight K negative anomalies on primitive mantle normalized, multi-element diagrams. Subalkaline basalts (only at Sheridan Bluff) have lower concentrations of incompatible elements (La 14-16 ppm, Ba 110-144 ppm, and Sr 358-380 ppm), LaN/YbN ratios base of the East Antarctic craton and its replacement by warmer asthenosphere has been proposed for this region based on geophysical evidence (Heeszel et al., 2016). The volcanism may constrain the timing of this event. Heeszel et al. (2016) JGR, 121, 1758-1775.

  16. Ocean Basalt Simulator version 1 (OBS1): Trace element mass balance in adiabatic melting of a pyroxenite-bearing peridotite

    Science.gov (United States)

    Kimura, Jun-Ichi; Kawabata, Hiroshi

    2015-01-01

    We present a new numerical trace element mass balance model for adiabatic melting of a pyroxenite-bearing peridotite for estimating mantle potential temperature, depth of melting column, and pyroxenite fraction in the source mantle for a primary ocean basalt/picrite. The Ocean Basalt Simulator version 1 (OBS1) uses a thermodynamic model of adiabatic melting of a pyroxenite-bearing peridotite with experimentally/thermodynamically parameterized liquidus-solidus intervals and source mineralogy. OBS1 can be used to calculate a sequence of adiabatic melting with two melting models, including (1) melting of peridotite and pyroxenite sources with simple mixing of their fractional melts (melt-melt mixing model), and (2) pyroxenite melting, melt metasomatism in the host peridotite, and melting of the metasomatized peridotite (source-metasomatism model). OBS1 can be used to explore (1) the fractions of peridotite and pyroxenite, (2) mantle potential temperature, (3) pressure of termination of melting, (4) degree of melting, and (5) residual mode of the sources. In order to constrain these parameters, the model calculates a mass balance for 26 incompatible trace elements in the sources and in the generated basalt/picrite. OBS1 is coded in an Excel spreadsheet and runs with VBA macros. Using OBS1, we examine the source compositions and conditions of the mid-oceanic ridge basalts, Loihi-Koolau basalts in the Hawaiian hot spot, and Jurassic Shatsky Rise and Mikabu oceanic plateau basalts and picrites. The OBS1 model shows the physical conditions, chemical mass balance, and amount of pyroxenite in the source peridotite, which are keys to global mantle recycling.

  17. Mass dependent fractionation of stable chromium isotopes in mare basalts: Implications for the formation and the differentiation of the Moon

    Science.gov (United States)

    Bonnand, Pierre; Parkinson, Ian J.; Anand, Mahesh

    2016-02-01

    We present the first stable chromium isotopic data from mare basalts in order to investigate the similarity between the Moon and the Earth's mantle. A double spike technique coupled with MC-ICP-MS measurements was used to analyse 19 mare basalts, comprising high-Ti, low-Ti and KREEP-rich varieties. Chromium isotope ratios (δ53Cr) for mare basalts are positively correlated with indices of magmatic differentiation such as Mg# and Cr concentration which suggests that Cr isotopes were fractionated during magmatic differentiation. Modelling of the results provides evidence that spinel and pyroxene are the main phases controlling the Cr isotopic composition during fractional crystallisation. The most evolved samples have the lightest isotopic compositions, complemented by cumulates that are isotopically heavy. Two hypotheses are proposed to explain this fractionation: (i) equilibrium fractionation where heavy isotopes are preferentially incorporated into the spinel lattice and (ii) a difference in isotopic composition between Cr2+ and Cr3+ in the melt. However, both processes require magmatic temperatures below 1200 °C for appreciable Cr3+ to be present at the low oxygen fugacities found in the Moon (IW -1 to -2 log units). There is no isotopic difference between the most primitive high-Ti, low-Ti and KREEP basalts, which suggest that the sources of these basalts were homogeneous in terms of stable Cr isotopes. The least differentiated sample in our sample set is the low-Ti basalt 12016, characterised by a Cr isotopic composition of -0.222 ± 0.025‰, which is within error of the current BSE value (-0.124 ± 0.101‰). The similarity between the mantles of the Moon and Earth is consistent with a terrestrial origin for a major fraction of the lunar Cr. This similarity also suggests that Cr isotopes were not fractionated by core formation on the Moon.

  18. Petrological systematics of mid-ocean ridge basalts: Constraints on melt generation beneath ocean ridges

    Science.gov (United States)

    Langmuir, Charles H.; Klein, Emily M.; Plank, Terry

    Mid-ocean ridge basalts (MORB) are a consequence of pressure-release melting beneath ocean ridges, and contain much information concerning melt formation, melt migration and heterogeneity within the upper mantle. MORB major element chemical systematics can be divided into global and local aspects, once they have been corrected for low pressure fractionation and interlaboratory biases. Regional average compositions for ridges unaffected by hot spots ("normal" ridges) can be used to define the global correlations among normalized Na2O, FeO, TiO2 and SiO2 contents, CaO/Al2O3 ratios, axial depth and crustal thickness. Back-arc basins show similar correlations, but are offset to lower FeO and TiO2 contents. Some hot spots, such as the Azores and Galapagos, disrupt the systematics of nearby ridges and have the opposite relationships between FeO, Na2O and depth over distances of 1000 km. Local variations in basalt chemistry from slow- and fast-spreading ridges are distinct from one another. On slow-spreading ridges, correlations among the elements cross the global vector of variability at a high angle. On the fast-spreading East Pacific Rise (EPR), correlations among the elements are distinct from both global and slow-spreading compositional vectors, and involve two components of variation. Spreading rate does not control the global correlations, but influences the standard deviations of axial depth, crustal thickness, and MgO contents of basalts. Global correlations are not found in very incompatible trace elements, even for samples far from hot spots. Moderately compatible trace elements for normal ridges, however, correlate with the major elements. Trace element systematics are significantly different for the EPR and the mid-Atlantic Ridge (MAR). Normal portions of the MAR are very depleted in REE, with little variability; hot spots cause large long wavelength variations in REE abundances. Normal EPR basalts are significantly more enriched than MAR basalts from normal

  19. Geochemical and isotopic constraints on the genesis of the Jueluotage native copper mineralized basalt, Eastern Tianshan, Northwest China

    Science.gov (United States)

    Zhang, Dayu; Zhou, Taofa; Yuan, Feng; Fiorentini, Marco L.; Said, Nuru; Lu, Yongjun; Pirajno, Franco

    2013-09-01

    The Jueluotage native copper mineralized basalt is located in the Jueluotage Volcanic-sedimentary Belt, Eastern Tianshan, Xinjiang Uygur Autonomous region. The basalt, amygdaloidal basalt and tuff, which host native copper mineralization, were erupted in the lower strata of the Late Carboniferous Matoutan Formation. Whole-rock geochemistry shows that the basaltic occurrences at Shilipo, Heilongfeng, Changchengshan and Dongjianfeng have fractionated chondrite-normalized REE distributions and distinctly negative primitive mantle-normalized Nb, Ta and Ti anomalies. The whole-rock strontium, neodymium and lead isotopic data indicate low εSr(t) (-7.9 to +23.6), high εNd(t) (+2.5 to +7.1), with restricted 206Pb/204Pb (18.152-18.491), 207Pb/204Pb (15.521-15.562) and 208Pb/204Pb (37.978-38.251) ranges. On the basis of these data, we report that the Cu-bearing basalt is associated with high-iron tholeiitic basalts that were sourced from depleted continental lithosphere mantle garnet-bearing peridotite. The primary magma of the Cu-bearing basalt was: (1) relatively low in silica and magnesium; and (2) underwent only slight olivine and clinopyroxene crystal fractionation during the magmatic evolution process. In the Jueluotage belt, the Shilipo basalt lavas display significant geochemical similarities to numerous mafic intrusions that are present throughout the Jueluotage belt. Those mafic lavas and intrusions probably represent successive pulses of mafic magmatism, which lasted between ca. 310 and 270 Ma. A crucial empirical observation is that the Jueluotage volcanic-sedimentary belt is a well-known metallogenic province that contains a wide range of copper, nickel, gold, and iron mineral deposits. These mineral systems were formed at different times and are associated with radically different ore-forming processes. However, they are all within the Jueluotage belt, which is interpreted to be a suture zone between the Junggar and Tarim plates, northwestern China. We

  20. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 14. Repository preconceptual design studies: basalt

    International Nuclear Information System (INIS)

    1978-04-01

    This document describes a preconceptual design for a nuclear waste storage facility in basalt. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/15, ''Drawings for Repository Preconceptual Design Studies: Basalt.''

  1. Reappraising craft specialization and exchange in pre-contact Hawaii through non-destructive sourcing of basalt adze debitage

    International Nuclear Information System (INIS)

    Mills, P.R.; Lundblad, S.P.; Hon, K.; Moniz Nakamura, J.J.; Kahahane, E.L.; Drake-Raue, A.; Souza, T.M.; Wei, R.

    2011-01-01

    Depictions of pre-Contact Hawaiian complex societies are framed in self-sufficient small land units (Ahupua'a) that minimised the occurrence of long-distance commodity exchange and chiefly redistributive networks. We test the Ahupua'a model by using non-destructive Energy-Dispersive X-Ray Fluorescence (EDXRF) to source 955 basalt flakes and cores recovered from Kahalu'u Habitation Cave in the Kona district (∼AD 1600-1800). Findings suggest that less than 7% of the basalt debitage was obtained from local sources. (author). 48 refs., 7 figs., 4 tabs.

  2. Geochemistry of 24 Ma Basalts from Northeast Egypt: Implications for Small-Scale Convection Beneath the East African Rift System

    Science.gov (United States)

    Endress, C. A.; Furman, T.; Ali Abu El-Rus, M.

    2009-12-01

    Basalts ~24 Ma in the Cairo-Suez and Fayyum districts of NE Egypt represent the youngest and northernmost lavas potentially associated with the initiation of rifting of the Red Sea. The age of these basalts corresponds to a time period of significant regional magmatism that occurred subsequent to emplacement of 30 Ma flood basalts attributed to the Afar Plume in Ethiopia and Yemen. Beginning ~28 Ma, widespread magmatism occurred across supra-equatorial Africa in Hoggar (Algeria), Tibesti (Chad), Darfur (Sudan), Turkana (Kenya) and Samalat, Bahariya, Quesir and the Sinai Peninsula (Egypt) (e.g. Allegre et al., 1981; Meneisy, 1990; Baldridge et al., 1991; Wilson and Guiraud, 1992; Furman et al., 2006; Lucassen et al., 2008). Available geochemical and isotopic data indicate that Hoggar and Darfur basalts are similar to Turkana lavas, although no direct link between the N African lavas and the Kenya Plume has been made. New geochemical data on the NE Egyptian basalts provide insight into the thermochemical, isotopic, and mineralogical characteristics of the mantle beneath the region in which they were emplaced. The basalts are subalkaline with OIB-like incompatible trace element abundances and homogeneous major element, trace element and isotopic geochemistry. They display relatively flat ITE patterns, with notable positive Pb and negative P anomalies. Isotopic (143Nd/144Nd = 0.51274-0.51285, 87Sr/86Sr = 0.7049-0.7050) and trace element signatures (Ce/Pb = 16-22, Ba/Nb = 9-14, and La/Nb = 0.9-1.0) are consistent with melting of a sub-lithospheric source that has been slightly contaminated by continental crust during ascent and emplacement. The Pb isotopic ratios (206Pb/204Pb = 18.53-18.62, 207Pb/204Pb = 15.59-15.64, and 208Pb/204Pb = 38.80-39.00) in the Egyptian basalts are close to the range of those found in the 30 Ma Ethiopian flood basalts, which are distinct from the more highly radiogenic, high-μ type signature seen in basalts from Turkana, Darfur, and Hoggar

  3. The effect of rock composition on cyanobacterial weathering of crystalline basalt and rhyolite.

    Science.gov (United States)

    Olsson-Francis, K; Simpson, A E; Wolff-Boenisch, D; Cockell, C S

    2012-09-01

    The weathering of volcanic rocks contributes significantly to the global silicate weathering budget, effecting carbon dioxide drawdown and long-term climate control. The rate of chemical weathering is influenced by the composition of the rock. Rock-dwelling micro-organisms are known to play a role in changing the rate of weathering reactions; however, the influence of rock composition on bio-weathering is unknown. Cyanobacteria are known to be a ubiquitous surface taxon in volcanic rocks. In this study, we used a selection of fast and slow growing cyanobacterial species to compare microbial-mediated weathering of bulk crystalline rocks of basaltic and rhyolitic composition, under batch conditions. Cyanobacterial growth caused an increase in the pH of the medium and an acceleration of rock dissolution compared to the abiotic controls. For example, Anabaena cylindrica increased the linear release rate (R(i)(l)) of Ca, Mg, Si and K from the basalt by more than fivefold (5.21-12.48) and increased the pH of the medium by 1.9 units. Although A. cylindrica enhanced rhyolite weathering, the increase in R(i)(l) was less than threefold (2.04-2.97) and the pH increase was only 0.83 units. The R(i)(l) values obtained with A. cylindrica were at least ninefold greater with the basalt than the rhyolite, whereas in the abiotic controls, the difference was less than fivefold. Factors accounting for the slower rate of rhyolite weathering and lower biomass achieved are likely to include the higher content of quartz, which has a low rate of weathering and lower concentrations of bio-essential elements, such as, Ca, Fe and Mg, which are known to be important in controlling cyanobacterial growth. We show that at conditions where weathering is favoured, biota can enhance the difference between low and high Si-rock weathering. Our data show that cyanobacteria can play a significant role in enhancing rock weathering and likely have done since they evolved on the early Earth. © 2012

  4. Neogene Uplift and Magmatism of Anatolia: New Insights from Drainage Analysis and Basalt Geochemistry

    Science.gov (United States)

    McNab, F.; Ball, P.; Hoggard, M.; White, N.

    2017-12-01

    The origin of Anatolia's high elevation and low relief plateaux has been the subject of much recent debate. Marine sedimentary rocks distributed across Central and Eastern Anatolia require significant regional uplift in Neogene times. This uplift cannot be explained by the present-day pattern of crustal deformation which, particularly across Central and Western Anatolia, is dominanted by strike-slip and extensional faulting. Positive long wavelength free-air gravity anomalies combined with slow upper mantle seismic wave speeds suggest that the sub-lithospheric mantle provides substantial topographic support. A range of geodynamic processes have been invoked, including complex slab fragmentation and lithospheric delamination. The temporal and spatial evolution of the Anatolian landscape should be recorded by drainage networks. Indeed, major catchments contain prominent knickzones with heights of hundreds of meters and length scales of several hundred kilometers. The stream power formulation for fluvial erosion permits these knickzones to be interpreted in terms of uplift history along a river's length. Here, we jointly invert an inventory of 1,844 river profiles to determine a spatial and temporal uplift rate history. When calibrated against independent observations of uplift rate, the resultant history provides significant new constraints for the evolution of Anatolian topography. In our model, the bulk of this topography appears to grow in Neogene times. Uplift initiates in Eastern Anatolia and propagates westward at uplift rates of up to 0.5 mm/yr. Coeval with this phase of uplift, abundant basaltic magmatism has occurred throughout Anatolia. We have compiled an extensive database of published geochemical analyses. Using this database, we analyse spatial and temporal patterns of basaltic compositions to discriminate between different modes of melt generation. Two independent techniques for estimating asthenospheric potential temperatures from the compositions of

  5. Diffusion of Redox-Sensitive Elements in Basalt at Different Oxygen Fugacities

    Science.gov (United States)

    Szumila, I.; Trail, D.; Danielson, L. R.

    2017-01-01

    The terrestrial planets and moons of our solar system have differentiated over a range of oxygen fugacity conditions. Basalts formed from magmas on the Earth cover a range of more oxidized states (from approximately IW (iron wustite) plus 2 to approximately FMQ (fayalite-magnetite-quartz) plus 3) than crustal rocks from Mars (IW to approximately IW plus 3), and basalts from the Moon are more reduced than both, ranging from IW to IW minus 2. The small body Vesta differentiated around IW minus 4. Characterization of redox sensitive elements' diffusivities will offer insight into behavior of these elements as a function of f (fugacity of) O2 for these planetary bodies. Here, we report a systematic study of the diffusion of redox-sensitive elements in basaltic melts with varying oxygen fugacities (fO2) for trace elements, V, Nb, W, Mo, La, Ce, Pr, Sm, Eu, Gd, Ta, and W. Since fO2 is an intensive variable that is different for the reservoirs of various planets and moons in our solar system, it is important to characterize how changes in redox states will affect diffusion. We conducted experiments in a piston cylinder device at 1300 degrees Centigrade and 1 gigapascal, at the University of Rochester and NASA Johnson Space Center. We buffered some experiments at Ru-RuO2 (FMQ plus 6.00), and conducted other experiments within either a graphite or Mo capsule, which corresponds to fO2s of either FMQ minus1.2, or FMQ minus 3.00, respectively. Characterizing the diffusivities of redox sensitive elements at different fO2s is important because some elements, like Eu, have varying valence states, such as Eu (sup 2 plus) and Eu (sup 3 plus). Differences in charge and ion radii may lead to differences in diffusivities within silicate melts. This could, lead to formation of a Eu anomaly by diffusion, the magnitude of which may be controlled by the fO2. Characterization of trace element diffusion is also important in understanding trace element fractionation. We found, during the

  6. Uranium isotope composition of a laterite profile during extreme weathering of basalt in Guangdong, South China

    Science.gov (United States)

    Huang, J.; Zhou, Z.; Gong, Y.; Lundstrom, C.; Huang, F.

    2015-12-01

    Rock weathering and soil formation in the critical zone are important for material cycle from the solid Earth to superficial system. Laterite is a major type of soil in South China forming at hot-humid climate, which has strong effect on the global uranium cycle. Uranium is closely related to the environmental redox condition because U is stable at U(Ⅳ) in anoxic condition and U(Ⅵ) as soluble uranyl ion (UO22+) under oxic circumstance. In order to understand the behavior of U isotopes during crust weathering, here we report uranium isotopic compositions of soil and base rock samples from a laterite profile originated from extreme weathering of basalt in Guangdong, South China. The uranium isotopic data were measured on a Nu Plasma MC-ICP-MS at the University of Illinois at Urbana-Champaign using the double spike method. The δ238U of BCR-1 is -0.29±0.03‰ (relative to the international standard CRM-112A), corresponding to a 238U/235U ratio of 137.911±0.004. Our result of BCR-1 agrees with previous analyses (e.g., -0.28‰ in Weyer et al. 2008) [1]. U contents of the laterite profile decrease from 1.9 ppm to 0.9 ppm with depth, and peak at 160 - 170 cm (2.3 ppm), much higher than the U content of base rocks (~0.5 ppm). In contrary, U/Th of laterites is lower than that of base rock (0.27) except the peak at the depth of 160-170 cm (0.38), indicating significant U loss during weathering. Notably, U isotope compositions of soils show a small variation from -0.38 to -0.28‰, consistent with the base rock within analytical error (0.05‰ to 0.08‰, 2sd). Such small variation can be explained by a "rind effect" (Wang et al., 2015) [2], by which U(Ⅳ) can be completely oxidized to U(VI) layer by layer during basalt weathering by dissolved oxygen. Therefore, our study indicates that U loss during basalt weathering at the hot-humid climate does not change U isotope composition of superficial water system. [1] Weyer S. et al. (2008) Natural fractionation of 238U/235

  7. Iron Moessbauer spectra of lava from Jeju Island and its similarities to moon basalts

    International Nuclear Information System (INIS)

    Hong, S.R.; Haley, G.; Mullen, J.G.

    1990-01-01

    We report the result of measurements of the 57 Fe Moessbauer spectrum for powder samples of lava taken from four widely separated sites on Jeju island. The spectra consist of well defined quadrupole doublets having a 2+ charge state and indicate the presence of olivine, clinopyroxene and ilmenite. In addition we find a six line magnetically split hyperfine pattern characteristic of impure hematite, with considerable line broadening and reduced internal field. The observed spectra have a remarkable similarity to those found for moon basalts. A recently popularized ''collision ejection'' model for the moon formation would be consistent with our observations. The data is a particularly simple and direct illustration of the well-known fact that the iron silicates and ilmenite found on the moon are very similar in composition and relative abundance to that found on earth. (orig.)

  8. Geochemistry and petrogenesis of Rajahmundry trap basalts of Krishna-Godavari Basin, India

    Directory of Open Access Journals (Sweden)

    C. Manikyamba

    2015-05-01

    Full Text Available The Rajahmundry Trap Basalts (RTB are erupted through fault-controlled fissures in the Krishna-Godavari Basin (K-G Basin of Godavari Triple Junction, occurring as a unique outcrop sandwiched between Cretaceous and Tertiary sediments along the east coast of India. Detailed geochemical studies have revealed that RTB are mid-Ti (1.74–1.92 to high-Ti (2.04–2.81 basalts with a distinct quartz tholeiitic parentage. MgO (6.2–13.12 wt.%, Mg# (29–50 and Zr (109–202 ppm suggest that these basalts evolved by fractional crystallization during the ascent of the parent magma along deep-seated fractures. Moderate to high fractionation of HREE, as indicated by (Gd/YbN ratios (1.71–2.31 of RTB, suggest their generation through 3–5% melting of a Fe-rich mantle corresponding to the stability fields of spinel and garnet peridotite at depths of 60–100 km. Low K2O/P2O5 (0.26–1.26, high TiO2/P2O5 (6.74–16.79, La/Nb (0.89–1.45, Nb/Th > 8 (8.35–13, negative anomalies at Rb reflect minimum contamination by granitic continental crust. (Nb/LaPM ratios (0.66–1.1 of RTB are attributed to endogenic contamination resulted through recycling of subducted oceanic slab into the mantle. Pronounced Ba enrichment with relative depletion in Rb indicates assimilation of Infra- and Inter-trappean sediments of estuarine to shallow marine character. Geochemical compositions such as Al2O3/TiO2 (3.88–6.83, medium to high TiO2 (1.74–2.81 wt.%, positive Nb anomalies and LREE enrichment of these RTB attest to their mantle plume origin and indicate the generation of parent magma from a plume-related enriched mantle source with EM I signature. Ba/Th (46–247, Ba/La (3.96–28.51 and Th/Nb (0.08–0.13 ratios suggest that the source enrichment process was marked by recycling of subduction-processed oceanic crust and lithospheric components into the mantle. Zr/Hf (37–41 and Zr/Ba (0.51–3.24 indicate involvement of an asthenospheric mantle source. The

  9. Project characteristics monitoring report: BWIP (Basalt Waste Isolation Program) repository project

    Energy Technology Data Exchange (ETDEWEB)

    Friedli, E.A.; Herborn, D.I.; Taylor, C.D.; Tomlinson, K.M.

    1988-03-01

    This monitoring report has been prepared to show compliance with provisions of the Nuclear Waste Policy Act of 1982 (NWPA) and to provide local and state government agencies with information concerning the Basalt Waste Isolation Program (BWIP). This report contains data for the time period May 26, 1986 to February 1988. The data include employment figures, salaries, project purchases, taxes and fees paid, worker survey results, and project closedown personal interview summaries. This information has become particularly important since the decision in December 1987 to stop all BWIP activities except those for site reclamation. The Nuclear Waste Policy Amendments Act of 1987 requires nonreclamation work at the Hanford Site to stop as of March 22, 1988. 7 refs., 6 figs., 28 tabs.

  10. Project characteristics monitoring report: BWIP [Basalt Waste Isolation Program] repository project

    International Nuclear Information System (INIS)

    Friedli, E.A.; Herborn, D.I.; Taylor, C.D.; Tomlinson, K.M.

    1988-03-01

    This monitoring report has been prepared to show compliance with provisions of the Nuclear Waste Policy Act of 1982 (NWPA) and to provide local and state government agencies with information concerning the Basalt Waste Isolation Program (BWIP). This report contains data for the time period May 26, 1986 to February 1988. The data include employment figures, salaries, project purchases, taxes and fees paid, worker survey results, and project closedown personal interview summaries. This information has become particularly important since the decision in December 1987 to stop all BWIP activities except those for site reclamation. The Nuclear Waste Policy Amendments Act of 1987 requires nonreclamation work at the Hanford Site to stop as of March 22, 1988. 7 refs., 6 figs., 28 tabs

  11. Decreasing Magmatic Footprints of Individual Volcanos in a Waning Basaltic Field

    Energy Technology Data Exchange (ETDEWEB)

    G.A> Valentine; F.V. Perry

    2006-06-06

    The distribution and characteristics of individual basaltic volcanoes in the waning Southwestern Nevada Volcanic Field provide insight into the changing physical nature of magmatism and the controls on volcano location. During Pliocene-Pleistocene times the volumes of individual volcanoes have decreased by more than one order of magnitude, as have fissure lengths and inferred lava effusion rates. Eruptions evolved from Hawaiian-style eruptions with extensive lavas to eruptions characterized by small pulses of lava and Strombolian to violent Strombolian mechanisms. These trends indicate progressively decreasing partial melting and length scales, or magmatic footprints, of mantle source zones for individual volcanoes. The location of each volcano is determined by the location of its magmatic footprint at depth, and only by shallow structural and topographic features that are within that footprint. The locations of future volcanoes in a waning system are less likely to be determined by large-scale topography or structures than were older, larger volume volcanoes.

  12. Study of the mechanical properties of hybrid composite basalt / alumina / shells for brake lining pads

    Science.gov (United States)

    Adi Atmika, I. K.; Ary Subagia, IDG.; Surata, I. W.; Sutantra, I. N.

    2017-05-01

    Brake lining pad as one of the active safety components in motor vehicles has been studied thoroughly. Asbestos is the main material forming the brake in addition to other alloy materials that have a negative impact on health and the environment. This paper explain the behavior of hybrid composites phenolic resin with basalt/alumina/clamshell powder reinforced on brake lining pad. This materials has been manufactured use compaction and sintering process through any steps, that an emphasis of 2,000 kg for 30 minutes at a constant temperature of 150° C. The research aims to investigate hardness characteristic of hybrid composite that test using the vickers according to standard ASTM E-384. The reinforced materials and phenolic resin composition is 60%: 40%. The results show for the average hardness VHN to 24.18, 25.11, 26.34, 27.21 and 28.83. The average hardness hybrid composite shows the hardness harder than asbestos materials.

  13. Thermal Emission Spectra of Silica-coated Basalt and Considerations for Martian Surface Mineralogy

    Science.gov (United States)

    Kraft, M. D.; Sharp, T. G.; Michalski, J. R.

    2003-01-01

    Among the most important discoveries made during the Mars Global Surveyor (MGS) mission was that the rocky materials of Mars are broadly divisible into two distinct rock types. The geological significance of this finding is dependent on the mineralogy of these rock types as well as their geographic and stratigraphic positions. Much work has yet to be done to understand these relationships and the small-scale variability of these units. For now, it is worth considering various scenarios that could have resulted in Mars global-scale mineralogical dichotomy. Such work will make clearer what must be looked for in Thermal Emission Spectrometer (TES) and Thermal Imaging Spectrometer (THEMIS) data, what to test with other data sets, and what geological processes can be considered or ruled out as we advance with interpreting Martian geologic history. Here, we suggest that exogenic coatings of secondary silica on basaltic rocks may provide a plausible explanation for the newly discovered distribution of rock types.

  14. Implications of Zn/Fe ratios for the sources of Colorado Plateau basalts

    Science.gov (United States)

    Rudzitis, S.; Reid, M. R.

    2011-12-01

    Early Miocene to recent mafic magmatism migrated across the Arizona Transition Zone towards the center of the stable Colorado Plateau at a rate of ~ 3-6 km/Myr (Roy et al., 2009). Present-day volcanic centers are close to a stepwise change in the thickness of the lithosphere between the Colorado Plateau and Basin and Range. Accordingly, volcanic migration might track progressive thinning of the lithosphere towards the center of the Colorado Plateau. This project aims to determine the conditions of melt generation across the transition zone in order to investigate the temporal/spatial correlation between volcanism and thinning of the Colorado Plateau lithosphere. Pressure and temperature estimates for Colorado Plateau basalts can be obtained from the Mg and Si contents of melts (Lee et al, 2009) but require melting of a peridotitic source. Eclogite and pyroxenite xenoliths reported in Colorado Plateau basalts show that melt sources could be olivine-poor. Zn/Fe ratios in melts can help to distinguish contributions from olivine-poor sources because they are sensitive to differences in bulk chemistry and to mineralogy (Le Roux et al., 2010). Specifically, Zn/Fe is not fractionated between melt, olivine, and orthopyroxene, but is highly fractionated when clinopyroxene and garnet are present. Our work to date has focused on laser ablation-IC-PMS analysis of individual olivine grains from high-Mg basalts (>8.0 wt. %) from the San Francisco and Mormon Mountain volcanic fields. Preliminary values of Zn/Fe ratios that represent the averages of multiple analyses of several grains in individual samples range from 7.9 to 9.3 (x10000). Variations of up to 1.7 (x10000) in the ratios exist between individual grains within samples and could be the result of co-crystallization of clinopyroxene with olivine. The lowest values in each sample should approach the Zn/Fe ratios of parental melts, and are, in turn, similar to MORB values and predicted peridotite melts. The results suggest

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  16. Review of Y/OWI/TM-36: repository design performance in salt, granite, shale or basalt

    International Nuclear Information System (INIS)

    Talbot, R.; Nair, O.B.

    1979-09-01

    As part of the ongoing work by the Lawrence Livermore Laboratory to evaluate repository design performance, this memorandum presents a review of the preconceptual repository design described in Y/OWI/TM-36, Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, April 1978. The purpose of this review is: to assess the adequacy of the design procedures and assumptions; to identify inappropriate or unsubstantiated design issues; to identify areas where additional numerical analyses may be required; and to develop data for inclusion in a reference repository design. The preconceptual repository design is presented in the form of 23 volumes of data base, analyses, and design layouts for four rock types: bedded salt, shale, granite and basalt. This memorandum reviews all four repository designs

  17. Comparative study of waste emplacement configurations for the nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Lee, Y.J.; Julien, H.L.; Schmidt, B.; Henry, K.H.; Parsons, Brinckerhoff, Quade and Douglas, Inc., San Francisco, CA; Rockwell Hanford Operations, Richland, WA)

    1985-01-01

    Various alternative waste emplacement concepts were evaluated and compared in order to select a waste emplacement configuration for the Nuclear Waste Repository in Basalt (NWRB). Based on screening of 51 feasible configurations, 11 alternative waste emplacement concepts warranted further evaluation. All of these configurations were analyzed in sufficient detail to assess the technical feasibility of each configuration and to allow a comparative evaluation. Based on the evaluation, the alternatives of greatest merit are, in order of preference: horizontal short-hole emplacements with single canisters close to room walls, with holes either at a 90 0 or 45 0 angle to the room; angled short-hole emplacement in the floor; asymmetric, long-hole, horizontal multiple canister emplacement; and angled short-hole emplacement off the floor corner. Other alternatives, including an in-room and a vertical emplacement configuration, were found to have significantly lower merit. This paper summarizes the technical evaluations that have led to this conclusion

  18. EVALUATION OF EFFECTIVE PROPERTIES OF BASALT TEXTILE REINFORCED CERAMIC MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    Soňa Valentová

    2017-11-01

    Full Text Available The present paper is concerned with the analysis of a ceramic matrix composite, more specifically the plain weave textile fabric composite made of basalt fibers embedded into the pyrolyzed polysiloxane matrix. Attention is paid to the determination of effective elastic properties of the yarn via homogenization based on the Mori-Tanaka averaging scheme and the 1st order numerical homogenization method adopting a suitable representative computational model. The latter approach is then employed to simulate the response of the yarn when loaded beyond the elastic limits. The required mechanical properties of individual material phases are directly measured using nanoindentation with in-build scanning probe microscopy. Applicability of the proposed computational methodology is supported by the analysis of a unidirectional fibrous composite, representing the yarn, subjected to a macroscopically uniform strain.

  19. Assessment of the rock burst potential in basalt at the Hanford Site

    International Nuclear Information System (INIS)

    Blake, W.

    1984-01-01

    The phenomenon of rock bursting has been reviewed and specific case histories have been presented, along with the measures most commonly taken to minimize their occurrence and effects. A combination of high stresses and brittle rock types is necessary to initiate bursting but is not sufficient to do so unless other parameters are present (i.e. an extensive mined-out area, a high extraction ratio, and geologic structures, or discontinuities). Since none of these parameters will result from the construction of a deep underground nuclear waste repository in basalt at the Hanford Site in Southeastern Washington, rock bursting should not occur either during or after this construction. 75 refs., 35 figs., 2 tabs

  20. Geology of Pine and Crater Buttes: two basaltic constructs on the far eastern Snake River Plain

    International Nuclear Information System (INIS)

    Mazierski, P.F.; King, J.S.

    1987-01-01

    The emplacement history and petrochemical evolution of the volcanics associated with Pine Butte, Crater Butte, and other nearby vents are developed and described. Four major vents were identified in the study area and their associated eruptive products were mapped. All of the vents show a marked physical elongation or linear orientation coincident with the observed rift set. Planetary exploration has revealed the importance of volcanic processes in the genesis and modification of extraterrestrial surfaces. Interpretation of surface features has identified plains-type basaltic volcanism in various mare regions of the Moon and the volcanic provinces of Mars. Identification of these areas with features that appear analogous to those observed in the Pine Butte area suggests similar styles of eruption and mode of emplacement. Such terrestrial analogies serve as a method to interpret the evolution of volcanic planetary surfaces on the inner planets

  1. Design and installation of deep multilevel piezometer nests in Columbia River basalts at the Hanford Site, Washington

    International Nuclear Information System (INIS)

    Jackson, R.L.; Veatch, M.D.

    1985-04-01

    The Basalt Waste Isolation Project (BWIP) was established in 1976 as part of the National Waste Terminal Storage Program, now the Office of Civilian Radioactive Waste Management. The BWIP objective is to assess the suitability of basalt as a repository medium for the long-term storage of commercial high-level radioactive waste. As part of the hydrogeologic characterization activities, BWIP designed and installed multilevel piezometer nests at three borehole cluster sites within and adjacent to the 18-square-mile reference repository location. These borehole cluster sites will provide multilevel piezometric baseline data across the reference repository location prior to, during, and after drilling a large-diameter exploratory shaft. They will also be used to monitor future hydraulic stress tests on a large scale. Three series of piezometer nests (A-, C-, and D-series) were installed at three borehole cluster sites in nine hydrogeologic units from a depth of about 500 to 3700 feet within the Columbia River Basalt Group. These multilevel monitoring zones are isolated from each other and the next overlying hydrogeologic unit by high-density cement seals. The A-series piezometer nests monitor two shallow sedimentary units. The C-series piezometer nests monitor basalt flow tops in the six deepest zones. The D-series piezometer monitors an intermediate sedimentary unit. Each piezometer tube was developed by air-lift pumping to complete the installtion prior to installing downhole pressure transducers. 23 refs., 10 figs., 1 tab

  2. Probability encoding of hydrologic parameters for basalt. Elicitation of expert opinions from a panel of five consulting hydrologists

    International Nuclear Information System (INIS)

    Runchal, A.K.; Merkhofer, M.W.; Olmsted, E.; Davis, J.D.

    1984-11-01

    The Columbia River basalts underlying the Hanford Site in Washington State are being considered as a possible location for a geologic repository for high-level nuclear waste. To investigate the feasibility of a repository at this site, the hydrologic parameters of the site must be evaluated. Among hydrologic parameters of particular interest are the effective porosity of the Cohassett basalt flow top and flow interior and the vertical-to-horizontal hydraulic conductivity, or anisotropy ratio, of the Cohassett basalt flow interior. The Cohassett basalt flow is the prime candidate horizon for repository studies. Site-specific data for these hydrologic parameters are currently inadequate for the purpose of preliminary assessment of candidate repository performance. To obtain credible, auditable, and independently derived estimates of the specified hydrologic parameters, a panel of five nationally recognized hydrologists was assembled. Their expert judgments were quantified during two rounds of Delphi process by means of a probability encoding method developed to estimate the probability distributions of the selected hydrologic variables. The results indicate significant differences of expert opinion for cumulative probabilities of less than 10% and greater than 90%, but relatively close agreement in the middle ranges of values. The principal causes of the diversity of opinion are believed to be the lack of site-specific data and the absence of a single, widely accepted, conceptual or theoretical basis for analyzing these variables

  3. Probability encoding of hydrologic parameters for basalt. Elicitation of expert opinions from a panel of five consulting hydrologists

    Energy Technology Data Exchange (ETDEWEB)

    Runchal, A.K.; Merkhofer, M.W.; Olmsted, E.; Davis, J.D.

    1984-11-01

    The Columbia River basalts underlying the Hanford Site in Washington State are being considered as a possible location for a geologic repository for high-level nuclear waste. To investigate the feasibility of a repository at this site, the hydrologic parameters of the site must be evaluated. Among hydrologic parameters of particular interest are the effective porosity of the Cohassett basalt flow top and flow interior and the vertical-to-horizontal hydraulic conductivity, or anisotropy ratio, of the Cohassett basalt flow interior. The Cohassett basalt flow is the prime candidate horizon for repository studies. Site-specific data for these hydrologic parameters are currently inadequate for the purpose of preliminary assessment of candidate repository performance. To obtain credible, auditable, and independently derived estimates of the specified hydrologic parameters, a panel of five nationally recognized hydrologists was assembled. Their expert judgments were quantified during two rounds of Delphi process by means of a probability encoding method developed to estimate the probability distributions of the selected hydrologic variables. The results indicate significant differences of expert opinion for cumulative probabilities of less than 10% and greater than 90%, but relatively close agreement in the middle ranges of values. The principal causes of the diversity of opinion are believed to be the lack of site-specific data and the absence of a single, widely accepted, conceptual or theoretical basis for analyzing these variables.

  4. Mineralization of Bacteria in Terrestrial Basaltic Rocks: Comparison With Possible Biogenic Features in Martian Meteorite Allan Hills 84001

    Science.gov (United States)

    Thomas-Keprta, K. L.; McKay, D. S.; Wentworth, S. J.; Stevens, T. O.; Taunton, A. E.; Allen, C. C.; Gibson, E. K., Jr.; Romanek, C. S.

    1998-01-01

    The identification of biogenic features altered by diagenesis or mineralization is important in determining whether specific features in terrestrial rocks and in meteorites may have a biogenic origin. Unfortunately, few studies have addressed the formation of biogenic features in igneous rocks, which may be important to these phenomena, including the controversy over possible biogenic features in basaltic martian meteorite ALH84001. To explore the presence of biogenic features in igneous rocks, we examined microcosms growing in basaltic small-scale experimental growth chambers or microcosms. Microbial communities were harvested from aquifers of the Columbia River Basalt (CRB) group and grown in a microcosm containing unweathered basalt chips and groundwater (technique described in. These microcosms simulated natural growth conditions in the deep subsurface of the CRB, which should be a good terrestrial analog for any putative martian subsurface ecosystem that may have once included ALH84001. Here we present new size measurements and photomicrographs comparing the putative martian fossils to biogenic material in the CRB microcosms. The range of size and shapes of the biogenic features on the CRB microcosm chips overlaps with and is similar to those on ALH84001 chips. Although this present work does not provide evidence for the biogenicity of ALH84001 features, we believe that, based on criteria of size, shape, and general morphology, a biogenic interpretation for the ALH84001 features remains plausible.

  5. Chromium Oxidation State in Planetary Basalts: Oxygen Fugacity Indicator and Critical Variable for Cr-Spinel Stability

    Science.gov (United States)

    Bell, A. S.; Burger, P. V.; Le, Loan; Papike, J. J.; Jone, J.; Shearer, C. K.

    2014-01-01

    Cr is a ubiquitous and relatively abundant minor element in basaltic, planetary magmas. At the reduced oxidation states (basalts Cr is present in melts as both divalent and trivalent forms. The ratio of trivalent to divalent Cr present in the melt has many consequences for the stability and Cr concentration of magmatic phases such as spinel, clinopyroxene, and olivine. However, understanding the Cr valence in quenched melts has historically been plagued with analytical issues, and only recently has reliable methodology for quantifying Cr valence in quenched melts been developed. Despite this substantial difficulty, the pioneering works of Hanson and Jones and Berry and O'Neill provided important insights into the oxidation state of Cr in in silicate melts. Here we present a series of 1-bar gas mixing experiments performed with a Fe-rich basaltic melt in which have determined the Cr redox ratio of the melt at over a range of fO2 values by measuring this quantity in olivine with X-ray Absorption Near Edge Spectroscopy (XANES). The measured Cr redox ratio of the olivine phenocrysts can be readily converted to the ratio present in the conjugate melt via the ratio of crystal-liquid partition coefficients for Cr3+ and Cr2+. We have applied these results to modeling Cr spinel stability and Cr redox ratios in a primitive, iron-rich martian basalt.

  6. Post-collisional basalts of the Acampamento Velho Formation, Camaquã Basin, São Gabriel Terrane, southernmost Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Alberto Vedana

    Full Text Available ABSTRACT: The basic volcanic rocks in the Palma region, southern portion of the São Gabriel Terrane, have always been interpreted as generated during the active subduction period of the São Gabriel orogeny (Cryogenian. This terrane was built as the result of the Charrua Ocean closure between 900-680 Ma. The basalts show a subhorizontal igneous flow foliation and porphyritic texture, with plagioclase phenocrysts in a thin matrix composed of plagioclase, augite and magnetite, commonly altered to actinolite, chlorite and epidote. They have amygdales and veinlets reflecting a pervasive hydrothermal phase and are affected by thermal metamorphism related to Jaguari granite intrusion. Two samples were dated by the U-Pb zircon geochronology and yielded crystallization ages of 563±2 Ma and 573±6 Ma. The basalts have transitional composition from tholeiitic to calc-alkaline, metaluminous character, trace elements patterns rich in large-ion lithophile element (LILE with negative anomalies of Nb, P and Ti, slight enrichment in light rare-earth elements (LREE and horizontal pattern of heavy rare earth elements (HREE. The data allow interpreting the basalts as belonging to the Acampamento Velho Formation of the Camaquã Basin, and related to the basalts of the Ramada and Taquarembó plateaus. These associations represent the final evolution of the volcanism generated in the post-collisional period of the Dom Feliciano Belt.

  7. Ground penetrating radar and seismic refraction investigation of fracture patterns in the basalt of Lucky Peak near Boise, Idaho

    International Nuclear Information System (INIS)

    Dougherty, M.E.; Hudson, W.K.; Kay, S.E.; Vincent, R.J.

    1994-01-01

    In hard rock environments, fluid flow and basement integrity are often controlled by the degree and connectivity of fracturing on an outcrop scale, rather than strictly by laboratory values of the permeability and competence of the matrix rock. Therefore, in many cases it is important to have a subsurface image of fracture characteristics of rock units in addition to an image of gross rock type. Fortunately, within a single rock type, many physical properties on outcrop scale are greatly influenced by fracturing, and changes in these physical properties should be detectable through the innovative use of geophysical methods. Work presented here is an attempt to use surface geophysical methods to delineate areas within a basalt flow which display different fracture characteristics and which have different electrical and seismic properties. The Basalt of Luck Peak is an intracanyon basalt flow exposed in cliffs around Lucky Peak Reservoir and in a terrace downstream from Lucky Peak Dam near Boise, Idaho. Visible in the face of the terrace below Lucky Peak Dam are the colonnade and entablature structures characteristic of differential cooling rates within basalt flows. Exposure of structural units within the cliff face is used to ground truth results from ground penetrating radar (GPR) and seismic refraction data collected along a line running perpendicular and away from the top edge of the cliff. 19 refs., 6 figs

  8. Genomic evidence for the Wood-Ljungdahl pathway for carbon fixation in warm basaltic ocean crust

    Science.gov (United States)

    Smith, A. R.; Fisk, M. R.; Mueller, R.; Colwell, F. S.; Mason, O. U.; Popa, R.

    2016-12-01

    Microbial life in the deep suboceanic aquifer can harness geochemical energy resulting from water-rock reactions and contribute to carbon cycling in the ocean via primary production, or chemosynthesis. Iron-bearing minerals such as olivine in oceanic crust can produce molecular hydrogen, small molecular weight hydrocarbons, and hydrogen sulfide as they react with seawater. Although this generally occurs in serpentinizing systems at very high temperatures deep in the subsurface, it has also been hypothesized to drive the subseafloor microbial ecosystems present in shallower basaltic aquifers. We present genome-based evidence for chemolithoautotrophic microbes present on the surface of olivine incubated in Juan de Fuca Ridge basaltic ocean crust for a 4-year period. These metagenome-derived genomes show dominant taxa capable of using both branches of the Wood-Ljungdahl pathway for carbon fixation and energy generation. This pathway uses molecular hydrogen potentially derived from the olivine surface as it reacts with seawater and CO2 which is inherent to seawater. These taxa were not reported from aquifer fluid samples, but have been found only in association with mineral surfaces in this study location. Most taxa in this simple community are distant relatives of cultured taxa; therefore this genome information is crucial to understanding how the subseafloor aquifer community is structured, how it obtains energy, how it cycles carbon, and gives us keys to help cultivate these organisms in the laboratory. Our findings also support the Subsurface Lithoautotrophic Microbial Ecosystem (SLiME) hypothesis and have implications for understanding life on early Earth and the potential for life in the Martian subsurface.

  9. Large explosive basaltic eruptions at Katla volcano, Iceland: Fragmentation, grain size and eruption dynamics

    Science.gov (United States)

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

    2018-04-01

    Katla volcano in Iceland produces hazardous large explosive basaltic eruptions on a regular basis, but very little quantitative data for future hazard assessments exist. Here details on fragmentation mechanism and eruption dynamics are derived from a study of deposit stratigraphy with detailed granulometry and grain morphology analysis, granulometric modeling, componentry and the new quantitative regularity index model of fragmentation mechanism. We show that magma/water interaction is important in the ash generation process, but to a variable extent. By investigating the large explosive basaltic eruptions from 1755 and 1625, we document that eruptions of similar size and magma geochemistry can have very different fragmentation dynamics. Our models show that fragmentation in the 1755 eruption was a combination of magmatic degassing and magma/water-interaction with the most magma/water-interaction at the beginning of the eruption. The fragmentation of the 1625 eruption was initially also a combination of both magmatic and phreatomagmatic processes, but magma/water-interaction diminished progressively during the later stages of the eruption. However, intense magma/water interaction was reintroduced during the final stages of the eruption dominating the fine fragmentation at the end. This detailed study of fragmentation changes documents that subglacial eruptions have highly variable interaction with the melt water showing that the amount and access to melt water changes significantly during eruptions. While it is often difficult to reconstruct the progression of eruptions that have no quantitative observational record, this study shows that integrating field observations and granulometry with the new regularity index can form a coherent model of eruption evolution.

  10. Linking magma composition with volcano size and eruptive style in basaltic monogenetic systems

    Science.gov (United States)

    Smith, I. E.; McGee, L. E.; Cronin, S. J.

    2012-12-01

    Magma composition, volcano size and eruptive style (together with vent locations) are the definitive parameters of basaltic monogenetic systems. These variables are not independent, but the relationships between them are complex. Monogenetic volcano fields that episodically erupt small-volume, discrete magma batches such as the Auckland Volcanic Field (AVF, northern New Zealand), typically represent primary mantle melts variably modified by near source processes. In such cases, where the volume of magma is small, eruption styles are strongly controlled by the interaction of magma with the surficial environment and this is determined by both magma volume and its rise rate. The magmatic compositional extremes of primitive magmas in the AVF define a spectrum ranging from strongly silica-undersaturated nephelinite to sub-alkalic basalt. Nephelinites are low SiO2 (~40 wt.%), highly incompatible-element enriched compositions, representing very low degrees of partial melting (<2%) in the asthenospheric mantle. Higher SiO2 (~48 wt.%) sub-alkalic compositions have lower incompatible element contents representing higher degrees of melting (~<5%) at slightly shallower depths. Geochemical modeling indicates that all of these magmas are sourced within the same general mantle region at depths of 80-70 km. The two compositional extremes also define extremes in volume of magma and ultimately magma flux at the surface. The surficial environment of the AVF is characterized by highly water saturated sediments of variable competency and many pressurized aquifer systems. Where there is a combination of small volumes and low flux rates, environmental factors dominate and phreatomagmatic explosive eruptions ensue, forming tuff cones, rings and maars. Larger volumes and flux rates result in dry eruptions forming cinder cones and lava fields. Thus at a fundamental level defining magma source characteristics and temporal or spatial variation in these (such as cyclic or evolutionary trends

  11. Corrosion of copper and copper alloys in a basaltic repository environment

    International Nuclear Information System (INIS)

    Brehm, W.F.

    1990-01-01

    Corrosion testing done on copper and copper alloys in support of the basalt repository program is discussed. Tests were performed under anoxic conditions at 50C, 100C, 150C and 200C in the presence of a saturated basalt-bentonite packing. Tests were also performed in an air/steam mixture at temperatures between 150C and 200C. Some tests, particularly those in air/steam mixtures, were done in the presence of radiation fields of 10 2 , 10 3 or 10 4 rad/h. Exposure periods were up to 28 months. A synthetic groundwater, Grande Ronde ≠4, was used. The materials studied were ASTM B402μm·a for copper and 17 μm·a for cupronickel, but the average rates were muμm·a was obtained. The rates at longer times were less than a third of this value. Corrosion increased monotonically with time and temperature. Chalcocite (Cu 2 S) was the corrosion product at 200C. There was no detectable radiation effect, and no pitting was observed. In air/steam corrosion was uniform with no pitting. Linear corrosion was observed for pure copper. The maximum corrosion penetration after 25 months was 0.13 mm at 300C; cupronickel corroded more slowly, with a maximum penetration of 0.045mm after 25 months. Cuprite (Cu 2 O) and tenorite (CuO) were identified on cupronickel, but only Cu 2 O on copper. A pronounced radiation effect was seen at 250C, but not at 150C; the surface film morphology was different under irradiation. In the short term the presence of packing increased the corrosion rate. 5 refs

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

    Directory of Open Access Journals (Sweden)

    Cáceres, J. M.

    1996-06-01

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

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

  13. Simulating the development of basaltic volcanic fields for long-term hazard assessment

    Science.gov (United States)

    Connor, C.; Connor, L.; Germa, A.; Richardson, J. A.; Molisee, D. D.

    2017-12-01

    An important application of lava flow simulation is to model topography and surface geology in volcanic terrains with the goal of improving hazard assessments. We use a lava flow simulator, MOLASSES, coupled with codes modeling vent distribution, tephra dispersion and erosion to simulate the development of the surface geology and topography of basaltic volcanic fields. The simulation workflow begins by modeling the potential distribution of vents as a stochastic process using kernel density estimation, informed by geophysical models of the crust. Scoria cone dimensions, lava flow volume and thickness are then used to model multi-vent structures, breached scoria cones, and spatter cones. Tephra2, a tephra dispersion simulator is used to model medial deposition of tephra. MOLASSES is a cellular automata code that forecasts the dimensions of lava flows erupted at a point source on a digital elevation model. Lava and tephra are accumulated to construct topography, updating digital elevation models of the terrain. This topography is modified by erosion using the diffusion-advection equation and variable diffusivity for tephra, spatter and lava. Output from the simulator shows how the map geology of volcanic fields depends on vent density, volume of eruptive products, and the recurrence rate of volcanic activity. The potential for vent burial, which potentially biases hazard models, depends strongly on these factors. The erosion of scoria cones with time depends on vent density, and the likelihood of the scoria cone being re-surfaced by tephra fallout from younger adjacent cones. Our results suggest that quantitative treatment of geologic maps of volcanic fields using computer simulation will improve our understanding of the development of these basaltic volcanic fields and long-term hazard models.

  14. Subseafloor seawater-basalt-microbe reactions: Continuous sampling of borehole fluids in a ridge flank environment

    Science.gov (United States)

    Wheat, C. Geoffrey; Jannasch, Hans W.; Fisher, Andrew T.; Becker, Keir; Sharkey, Jessica; Hulme, Samuel

    2010-07-01

    Integrated Ocean Drilling Program (IODP) Hole 1301A was drilled, cased, and instrumented with a long-term, subseafloor observatory (CORK) on the eastern flank of the Juan de Fuca Ridge in summer 2004. This borehole is located 1 km south of ODP Hole 1026B and 5 km north of Baby Bare outcrop. Hole 1301A penetrates 262 m of sediment and 108 m of the uppermost 3.5 Ma basaltic basement in an area of warm (64°C) hydrothermal circulation. The borehole was instrumented, and those instruments were recovered 4 years later. Here we report chemical data from two continuous fluid samplers (OsmoSamplers) and temperature recording tools that monitored changes in the state of borehole (formation) fluids. These changes document the effects of drilling, fluid overpressure and flow, seawater-basalt interactions, and microbial metababolic activity. Initially, bottom seawater flowed into the borehole through a leak between concentric CORK casing strings. Eventually, the direction of flow reversed, and warm, altered formation fluid flowed into the borehole and discharged at the seafloor. This reversal occurred during 1 week in September 2007, 3 years after drilling operations ceased. The composition of the formation fluid around Hole 1301A generally lies within bounds defined by springs on Baby Bare outcrop (to the south) and fluids that discharged from Hole 1026B (to the north); deviations likely result from reactions with drilling products. Simple conservative mixing of two end-member fluids reveals reactions occurring within the crust, including nitrate reduction presumably by denitrifying microbes. The observed changes in borehole fluid composition provide the foundation for a conceptual model of chemical and microbial change during recharge of a warm ridge-flank hydrothermal system. This model can be tested through future scientific ocean drilling experiments.

  15. Structural control on basaltic dike and sill emplacement, Paiute Ridge mafic intrusion complex, southern Nevada

    International Nuclear Information System (INIS)

    Carter Krogh, K.E.; Valentine, G.A.

    1996-08-01

    Late Miocene basaltic sills and dikes in the Paiute Ridge area of southern nevada show evidence that their emplacement was structurally controlled. Basaltic dikes in this area formed by dilating pre-existing vertical to steeply E-dipping normal faults. Magma propagation along these faults must have required less energy than the creation of a self-propagated fracture at dike tips and the magma pressure must have been greater than the compressive stress perpendicular to the fault surface. N- to NE-trending en echelon dikes formed locally and are not obviously attached to the three main dikes in the area. The en echelon segments are probably pieces of deeper dikes, which are segmented perhaps as a result of a documented rotation of the regional stresses. Alternatively, changes in orientation of principal stresses in the vicinity of each en echelon dike could have resulted from local loads associated with paleotopographic highs or nearby structures. Sills locally branched off some dikes within 300 m of the paleosurface. These subhorizontal bodies occur consistently in the hanging wall block of the dike-injected faults, and intrude Tertiary tuffs near the Paleozoic-Tertiary contact. The authors suggest that the change in stresses near the earth's surface, the material strength of the tuff and paleozoic rocks, and the Paleozoic bedding dip direction probably controlled the location of sill formation and direction of sill propagation. The two largest sills deflected the overlying tuffs to form lopoliths, indicating that the magma pressure exceeded vertical stresses at that location and that the shallow level and large size of the sills allowed interaction with the free (earth's) surface. 32 refs., 4 figs., 1 tab

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

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

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

    2006-12-01

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

  18. Mid-IR Reflectance (DRIFT) Spectral Variations in Basaltic Mineralogy with Direction of Impact at Lonar Crater, India

    Science.gov (United States)

    Basavaiah, N.; Chavan, R. S.; Arif, M.

    2012-12-01

    Identification of spectral changes with the direction of impact has important implications for understanding the impact cratering phenomenon occurring on both terrestrial and extraterrestrial planets and also for geology of the crater. Fortuitously, Lonar Impact Crater (India) is the only well-preserved terrestrial simple crater excavated on Deccan basalts and serves as an excellent analogue to craters on Mars and Moon. An ~570 ka old Lonar crater was suggested to be formed by an oblique impact of a chondritic impactor that struck the pre-impact target from the east into a sequence of six basaltic Deccan flows and created a 1.88 km diameter crater with two layers of ejecta blanket. Here we report preliminary laboratory studies of spectral results on fine-grained rock powers (IR (4000-400 cm-1) Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy. The basalts were collected from two profiles in the east and south sections of the crater wall and the upper most crater rim, which later subdivided into sector-wise samples to carry out a systematic study of spectral properties of Lonar basalts, together with impact related samples of breccias and impact melts. For the first time, data of the shock metamorphism of Lonar basalt is examined using DRIFT spectroscopy. Infrared spectra of rock powders of relatively unshocked and shocked basalts are obtained to document the mineralogical variations and the distribution of primary (e.g. Plagioclase Feldspar, Pyroxene), and secondary Phyllosilicate minerals (e.g. Illite, Smectite, Montmorillonite, Saponite, Serpentine) with direction of impact. The spectral data between pre-impact unshocked and post-impact shocked basalts are interpreted to reflect the effect of shock pressure and alteration that rock have undergone. On western crater rim sector, typical silicate spectral features in 900-1200 cm-1 which attributed to Si-O stretching, are observed to change slightly in the width and shift in position as a result of

  19. Geochemical characterization of basalts from west of Khash (SE Iran: an approach to the nature of the mantle source

    Directory of Open Access Journals (Sweden)

    Zahra Firouzkouhi

    2017-07-01

    Full Text Available Monogenic basaltic cinder cones and lava flows from west of Khash are part of volcanic arc of northern Makran, formed as a result of subduction of Oman oceanic lithosphere beneath the Eurasian plate. The basalts belong to medium-K calc-alkaline series as they contain high Al2O3 (16.5- 19.04 wt. % and CaO (8.4- 12.0 wt. % and moderate amounts of K2O (0.5- 1.1 wt. %. They share arc geochemical features such as high LILE/HFSE ([Rb/Zr]N-MORB up to 19 LILE/LREE ([Ba/La]N-MORB up to 4.86 and LREE/HREE ([La/Yb]N-MORB up to 10, and depletion of Ta, Nb, Zr, and Ti relative to N-MORB. Partial melting models indicate that near-primary basalts were derived from an enriched source type mantle wedge peridotite after low to medium degrees (2-10% of partial melting. This source peridotite was enriched in LREE and LILE, by subduction derived fluids in the supra-subduction zone. Negative correlation of Th/La vs. Sm/La, and relationships between Pb/Ce and Th/Nb values of the studied basalts which are between two end compositions of global subducting sediment (GLOSS and N-MORB are indicative of significant contribution of subducting sediments to the genesis of the basaltic rocks. Estimates made using binary mixing model are indicative of about 16% of sediment participation in the magma genesis. Low Pb/Ce ratio (1.6 - 11.1, compared to OIB (>20 may be a signature of participation of fluids resulted from dehydration of the subducting slab

  20. Origin of co-existing basalts, high-Mg andesites, and adakites in the SW Japan hot subduction system

    Science.gov (United States)

    Kimura, J.; Kunikiyo, T.; Osaka, I.; Shimoshioiri, Y.; Katakuse, M.; Kakubuchi, S.; Nagao, T.; Furuyama, K.; Kamei, A.; Nakajima, J.; Stern, R. J.; Gill, J. B.

    2012-12-01

    In response to subduction of the young, hot Shikoku Basin of the Philippine Sea Plate (PSP) slab, arc magmas have been active throughout the late Cenozoic (<13 Ma) in the SW Japan arc. Extremely variable magma types occurred including oceanic island-type basalt (OIB), shoshonitc to mildly alkalic to sub-alkalic basalts with arc signatures, high-Mg andesites (HMAs), and adakitic andesites and dacites. The OIB-type basalts preceded the arc-type magmas. Therefore, the transition from OIB- to arc-types was related to opening of the Japan of Sea back-arc basin and subsequent re-initiation of PSP subduction. However, both the origin and tectonic implications of this magmatism are debated. Consequently, we analyzed the bulk rock geochemistry of 340 lava samples from seven Quaternary volcanoes and investigated their sources and melting conditions using a geochemical mass balance model, Arc Basalt Simulator version 4 (ABS4). Comparison to basement granitoids precludes adakite genesis in the lower crust. Instead, the ABS4 model suggests that the adakites are mostly slab melts plus minor interaction with mantle wedge peridotite (PERID). Increasing involvement of PERID during slab melt-fluxed mantle melting explains fairly well the geochemical variations of the shoshonites, mildly alkalic to sub-alkalic basalts, and HMAs. We propose that the generation of various magma types in the late Cenozoic SW Japan arc originated simply by "slab melt-fluxed mantle melting" with large variations in melting conditions including depth, temperature, degree of melting, and flux fractions. Such volcanism has been continuous from 13 Ma (Setouchi HMA) to the present, so that the hot subduction system, involving subduction of the Shikoku Basin spreading ridge, should be continuous since 13 Ma beneath the SW Japan arc. Our results further suggest that this atypically hot system generated diverse primary arc magmas from various degrees of flux melting even though the slab source components and sub

  1. Osmium isotope variations accompanying the eruption of a single lava flow field in the Columbia River Flood Basalt Province

    Science.gov (United States)

    Vye-Brown, C.; Gannoun, A.; Barry, T. L.; Self, S.; Burton, K. W.

    2013-04-01

    Geochemical interpretations of continental flood basalts usually assume that individual lava flows represent compositionally homogenous and rapidly erupted products of large well-mixed magma reservoirs. However, inflated pāhoehoe lavas may develop over considerable periods of time and preserve chemical variations that can be temporally linked through flow formation to eruption sequence thus providing an understanding of magma evolution over the timescale of a single eruption. This study presents comprehensive major, trace element and Re-Os isotope data for a single eruption that formed the 2660 km3 Sand Hollow flow field in the Columbia River Basalt Province, USA. Major and trace element variations accompanying flow emplacement (e.g. MgO 3.09-4.55 wt%, Ni 17.5-25.6 ppm) are consistent with fractional crystallisation, but other petrogenetic processes or variable sources cannot be distinguished. However, there is a systematic shift in the initial 187Os/188Os isotope composition of the magma (age corrected to 15.27 Ma), from 0.174 (lava core) to 1.444 (lava crust) within a single 35 m thick sheet lobe. Lava crust values are more radiogenic than any known mantle source, consistent with previous data indicating that neither an enriched reservoir nor the sub-continental lithospheric mantle are likely to have sourced these basalts. Rather, these data indicate that lavas emplaced during the earliest stages of eruption have higher degrees of crustal contamination. These results highlight the limitations of applying chemostratigraphic correlation across continental flood basalt provinces, the use of single data points to define melt sources and magmatic processes, and the dangers of using conventional isochron techniques in such basalt sequences for absolute chronology.

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

    Science.gov (United States)

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

    2009-12-01

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

  3. Field-trip guide to the vents, dikes, stratigraphy, and structure of the Columbia River Basalt Group, eastern Oregon and southeastern Washington

    Science.gov (United States)

    Camp, Victor E; Reidel, Stephen P.; Ross, Martin E.; Brown, Richard J.; Self, Stephen

    2017-06-22

    The Columbia River Basalt Group covers an area of more than 210,000 km2 with an estimated volume of 210,000 km3. As the youngest continental flood-basalt province on Earth (16.7–5.5 Ma), it is well preserved, with a coherent and detailed stratigraphy exposed in the deep canyonlands of eastern Oregon and southeastern Washington. The Columbia River flood-basalt province is often cited as a model for the study of similar provinces worldwide.This field-trip guide explores the main source region of the Columbia River Basalt Group and is written for trip participants attending the 2017 International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly in Portland, Oregon, USA. The first part of the guide provides an overview of the geologic features common in the Columbia River flood-basalt province and the stratigraphic terminology used in the Columbia River Basalt Group. The accompanying road log examines the stratigraphic evolution, eruption history, and structure of the province through a field examination of the lavas, dikes, and pyroclastic rocks of the Columbia River Basalt Group.

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

    Science.gov (United States)

    Abdollahi Azghan, Mehdi; Eslami-Farsani, Reza

    2018-02-01

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

  5. The crystallisation trends of spinels in tertiary basalts from Rhum and Muck and their petrogenetic significance. [chemical composition changes during crystal formation

    Science.gov (United States)

    Ridley, W. I.

    1977-01-01

    Spinels found in transitional olivine basalts from the Islands of Rhum and Muck in the British Tertiary Province are analyzed to determine their chemical variability and their relationship to silicate phases. Chemical zoning of the cores of spinels which spilled into the basaltic liquid may be due to a reaction between the spinel and the liquid resulting in more Fe- and Ti-rich spinels. In addition, a peritectic-type reaction seems to have occurred, causing the transformation of aluminum spinel to chrome spinel with precipitation of plagioclase. Changes in the basaltic liquid are reflected by these transformations in the spinel composition.

  6. A new method of discriminating different types of post-Archean ophiolitic basalts and their tectonic significance using Th-Nb and Ce-Dy-Yb systematics

    Directory of Open Access Journals (Sweden)

    Emilio Saccani

    2015-07-01

    Full Text Available In this paper, a new discrimination diagram using absolute measures of Th and Nb is applied to post-Archean ophiolites to best discriminate a large number of different ophiolitic basalts. This diagram was obtained using >2000 known ophiolitic basalts and was tested using ∼560 modern rocks from known tectonic settings. Ten different basaltic varieties from worldwide ophiolitic complexes have been examined. They include two basaltic types that have never been considered before, which are: (1 medium-Ti basalts (MTB generated at nascent forearc settings; (2 a type of mid-ocean ridge basalts showing garnet signature (G-MORB that characterizes Alpine-type (i.e., non volcanic rifted margins and ocean-continent transition zones (OCTZ. In the Th-Nb diagram, basalts generated in oceanic subduction-unrelated settings, rifted margins, and OCTZ can be distinguished from subduction-related basalts with a misclassification rate <1%. This diagram highlights the chemical variation of oceanic, rifted margin, and OCTZ basalts from depleted compositions to progressively more enriched compositions reflecting, in turn, the variance of source composition and degree of melting within the MORB-OIB array. It also highlights the chemical contributions of enriched (OIB-type components to mantle sources. Enrichment of Th relative to Nb is particularly effective for highlighting crustal input via subduction or crustal contamination. Basalts formed at continental margin arcs and island arc with a complex polygenetic crust can be distinguished from those generated in intra-oceanic arcs in supra-subduction zones (SSZ with a misclassification rate <1%. Within the SSZ group, two sub-settings can be recognized with a misclassification rate <0.5%. They are: (1 SSZ influenced by chemical contribution from subduction-derived components (forearc and intra-arc sub-settings characterized by island arc tholeiitic (IAT and boninitic basalts; (2 SSZ with no contribution from subduction

  7. A dynamic melting model for the origin of Apollo 15 olivine-normative and quartz-normative mare basalts

    Science.gov (United States)

    Vetter, Scott K.; Shervais, John W.

    1993-01-01

    Early studies of mare basalts from the Apollo 15 site established that two distinct groups are represented: the olivine-normative basalts (ONB) and the quartz-normative basalts (QNB). The ONB and QNB suites are distinguished petrographically by their phenocryst assemblages (the ONB's are olivine-phyric, the QNB's are generally pyroxene-phyric) and chemically by their major element compositions: the QNB's are higher in SiO2 and MgO/FeO, and lower in FeO and TiO2 than ONB's with similar MgO contents. Experimental data show that the QNB suite is derived from a more magnesian, olivine-normative parent magma, a conclusion which is supported by the recent discovery of high-SiO2 olivine-normative basalt clasts in breccia 15498. The high-SiO2 ONB's fall on olivine control lines with primitive QNB's, and least-squares mixing calculations are consistent with the high-SiO2 ONB's being parental to the more evolved QNB suite. These high-SiO2 ONB's are included as part of the 'QNB suite'. Our major element modeling results also are consistent with the conclusions of earlier studies which showed that the ONB and QNB suites cannot be related to one another by low pressure crystal fractionation. The combination of high Mg#, high SiO2, and low TiO2 in the QNB suite precludes a relationship to the ONB suite by simple removal of liquidus minerals (olivine and pigeonite). Despite these significant differences in petrography and major element composition, both groups have nearly identical trace element concentrations and chondrite-normalized abundance patterns. The major question to be addressed by any petrogenetic model for Apollo 15 mare basalts is how to form mare basalt suites with distinctly different major element characteristics but nearly identical trace element compositions. The similarity in trace element concentrations imply compositionally similar source regions and similar percent melting, but these conclusions are not easily reconciled with the observed differences in

  8. Radiocarbon as a Reactive Tracer for Tracking Permanent CO2 Storage in Basaltic Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Matter, Juerg [Columbia Univ., New York, NY (United States); Stute, Martin [Columbia Univ., New York, NY (United States); Schlosser, Peter [Columbia Univ., New York, NY (United States); Broecker, Wallace [Columbia Univ., New York, NY (United States)

    2015-09-30

    In view of concerns about the long-term integrity and containment of CO2 storage in geologic reservoirs, many efforts have been made to improve the monitoring, verification and accounting methods for geologically stored CO2. Our project aimed to demonstrate that carbon-14 (14C) could be used as a reactive tracer to monitor geochemical reactions and evaluate the extent of mineral trapping of CO2 in basaltic rocks. The capacity of a storage reservoir for mineral trapping of CO2 is largely a function of host rock composition. Mineral carbonation involves combining CO2 with divalent cations including Ca2+, Mg2+ and Fe2+. The most abundant geological sources for these cations are basaltic rocks. Based on initial storage capacity estimates, we know that basalts have the necessary capacity to store million to billion tons of CO2 via in situ mineral carbonation. However, little is known about CO2-fluid-rock reactions occurring in a basaltic storage reservoir during and post-CO2 injection. None of the common monitoring and verification techniques have been able to provide a surveying tool for mineral trapping. The most direct method for quantitative monitoring and accounting involves the tagging of the injected CO2 with 14C because 14C is not present in deep geologic reservoirs prior to injection. Accordingly, we conducted two CO2 injection tests at the CarbFix pilot injection site in Iceland to study the feasibility of 14C as a reactive tracer for monitoring CO2-fluid-rock reactions and CO2 mineralization. Our newly developed monitoring techniques, using 14C as a reactive tracer, have been successfully demonstrated. For the first time, permanent and safe disposal of CO2 as environmentally benign carbonate minerals in basaltic rocks could be shown. Over 95% of the injected CO2 at the Carb

  9. Origin of CaCl2 brines by basalt-seawater interaction: Insights provided by some simple mass balance calculations

    Science.gov (United States)

    Hardie, Lawrence A.

    1983-06-01

    Modern rift zone hydrothermal brines are typically CaCl2-bearing brines, an unusual chemical signature they share with certain oil field brines, fluid inclusions in ore minerals and a few uncommon saline lakes. Many origins have been suggested for such CaCl2 brines but in the Reykjanes, Iceland, geothermal system a strong empirical case can be made for a basalt-seawater interaction origin. To examine this mechanism of CaCl2 brine evolution some simple mass balance calculations were carried out. Average Reykjanes olivine tholeiite was “reacted” with average North Atlantic seawater to make an albite-chlorite-epidotesphene rock using Al2O3 as the conservative rock component and Cl as the conservative fluid component. The excess components released by the basalt to the fluid were “precipitated” at 275° C as quartz, calcite, anhydrite, magnetite and pyrite to complete the conversion to greenstone. The resulting fluid was a CaCl2 brine of seawater chlorinity with a composition remarkably similar to the actual Reykjanes brine at 1750 m depth. Thus, the calculations strongly support the idea that the Reykjanes CaCl2 brines result from “closed system” oceanic basalt-seawater interaction (albitization — chloritization mechanism) at greenschist facies temperatures. The calculation gives a seawater: basalt mass ratio of 3∶1 to 4∶1 (vol. ratio of 9∶1 to 12∶1), in keeping with experimental results, submarine vent data and with ocean crust cooling calculations. The brine becomes anoxic because there is insufficient dissolved or combined oxygen to balance all the Fe released from the basalt during alteration. Large excesses of Ca are released to the fluid and precipitate out in the form of anhydrite which essentially sweeps the brine free of sulfate leaving an elevated Ca concentration. The calculated rock-water interaction basically involves Na + Mg + SO4 ⇌ Ca + K, simulating chemical differences observed between oceanic basalts and greenstones from many

  10. Experimental Alteration of Basalt to Support Interpretation of Remote Sensing and In Situ Meausrements from Mars

    Science.gov (United States)

    Bell, M. S.

    2014-01-01

    Major occurrences of hydrous alteration minerals on Mars have been found in Noachian impact craters formed in basaltic targets and detected using visible/near infrared (VNIR) spectroscopy. Until recently phyllosilicates were detected only in craters in the southern hemisphere [1, 2]. However, it has been reported that at least nine craters in the northern plains apparently excavated thick layers of lava and sediment to expose phyllosilicates [3] as well. The MER (Mars Exploration Rovers) rovers previously reported results of in situ measurement indicating the presence of alteration minerals on Mars [4,5] and it was recently reported that the Mars Curiosity rover has detected alteration phases in situ at Yellowknife Bay in Gale crater as well [6,7]. An important discovery for Mars geochronology is that the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument on Curiosity detected phyllosilicates indicating that phyllosilicate formation on Mars extended beyond the Noachian Epoch [8]. These discoveries indicate that Mars was globally altered by water in the past but does not constrain formation conditions for alteration phase occurrences, which have important implications for the evolution of the surface and the biological potential on Mars. Understanding the alteration assemblages produced by a range of conditions is vital for the interpretation of phyllosilicate spectral signatures as well as in situ measurements and to decipher the environment and evolution of early Mars. The martian surface has been intensely altered by meteorite impacts whose effects include brecciation and melting of target materials as well as the initiation of hydrothermal circulation in a hydrous target [9,10,11,12]. Impact effects may facilitate aqueous alteration of a basaltic target because the rate of silicate dissolution is a function of the degree of crystallinity, surface area, and temperature. The resultant alteration mineralogies from shocked basaltic target material

  11. Quality of the ground water in basalt of the Columbia River group, Washington, Oregon, and Idaho

    Science.gov (United States)

    Newcomb, Reuben Clair

    1972-01-01

    The ground water within the 50,000-square-mile area of the layered basalt of the Columbia River Group is a generally uniform bicarbonate water having calcium and sodium in nearly equal amounts as the principal cations. water contains a relatively large amount of silica. The 525 chemical analyses indicate that the prevalent ground water is of two related kinds--a calcium and a sodium water. The sodium water is more common beneath the floors of the main synclinal valleys; the calcium water, elsewhere. In addition to the prevalent type, five special types form a small part of the ground water; four of these are natural and one is artificial. The four natural special types are: (1) calcium sodium chloride waters that rise from underlying sedimentary rocks west of the Cascade Range, (2) mineralized water at or near warm or hot springs, (3) water having unusual ion concentrations, especially of chloride, near sedimentary rocks intercalated at the edges of the basalt, and (4) more mineralized water near one locality of excess carbon dioxide. The one artificial kind of special ground water has resulted from unintentional artificial recharge incidental to irrigation in parts of central Washington. The solids dissolved in the ground water have been picked up on the surface, within the overburden, and from minerals and glasses within the basalt. Evidence for the removal of ions from solution is confined to calcium and magnesium, only small amounts of which are present in some of the sodium-rich water. Minor constituents, such as the heavy metals, alkali metals, and alkali earths, occur in the ground water in trace, or small, amounts. The natural radioactivity of the ground waters is very low. Except for a few of the saline calcium sodium chloride waters and a few occurrences of excessive nitrate, the ground water generally meets the common standards of water good for most ordinary uses, but some of it can be improved by treatment. The water is clear and colorless and has a

  12. Length Scales of Reactive Transport in Basalt: Hydrothermal Flow-through Experiments and Anhydrite Precipitation

    Science.gov (United States)

    Los, C.; Kahl, W. A.; Bach, W.

    2017-12-01

    Hydrothermal circulation is a large contributor to mass and heat exchange between oceanic lithosphere and hydrosphere. Cold, unaltered seawater infiltrates in the shallow basaltic crust, leading to sulfate precipitation and clogging of fluid pathways. Anhydrite (CaSO4) veins are common in hydrothermal discharge zones, where entrained seawater is heated and anhydrite quickly forms. Anhydrite is also found in hydrothermal recharge zones, but questions regarding time and length scale in this setting remain. To investigate element transport and anhydrite precipitation we have conducted flow-through experiments using a gypsum-undersaturated CaSO4 solution in pre-fractured basalt at 95, 110 and 140°C. Each run was terminated upon clogging of the input tubes, which took 2-8 weeks. The rock core was scanned before the run and weekly during the experiment using X-ray tomography. Fluid major element chemistry was analyzed using ICP-OES. Geochemical modeling with the software package EQ3/6 showed that the starting solution became supersaturated in anhydrite (SI=IAP/K of 2.5 or higher) in all cases upon heating to the experimental temperature. The software CRUNCH FLOW was used to analyze chemical effects over the length of the core (3cm). The 95°C run and a first run at 110°C did not show any anhydrite. Instead, hematite rosettes and sulfur-bearing (maximum of 1 wt.%) globular Fe-rich structures were present. Tomography images showed that fractures and pores were slightly thinned over the whole core length. Single pores in a second 110°C run and fractures in the 140°C run did show formation of anhydrite and quartz close to the outlet. CRUNCH FLOW modeling predicts the observed release of Mg, Fe, Si, Al, Na and K due to silicate dissolution close to the inlet, while the outlet area should contain some anhydrite. No other sulfur-bearing phases were predicted. The results of this study show that anhydrite needs a large supersaturation (SI>2.5) to precipitate at temperatures

  13. Rubbly Pahoehoe Lavas: An Important Component of Icelandic Basaltic Lava Flows

    Science.gov (United States)

    Guilbaud, M.; Self, S.; Blake, S.; Thordarson, T.; Keyzthelyi, L.

    2003-12-01

    Eruptions at rift zones often produce basaltic lava flows. Structural and textural study of historic and prehistoric flows gives important clues about emplacement processes. The 1783-4 eruption of Laki produced 14.7 km3 of lava from a fissure that opened along the Eastern Volcanic Zone of Iceland. The resulting 600 km2 lava flow-field presents a wide range of surface morphologies that we explored to study emplacement mechanisms. We present results from preliminary field, macroscopic, and microscopic analysis. Field observations show that along a single flow surface morphologies change from (1) flat (with a coherent continuous, pahoehoe(phh)-like crust), to (2) slabby (with a disrupted surface made of phh-like slabs), to (3) rubbly (with a rough surface covered by loose vesicular blocks), and then to (4) folded rubbly (with ridges of rubble several meters high). Features characteristic of flow growth by inflation are abundant. The changes are unidirectional in the above order but the sequence can be repeated. This occurred if the fluid lava stored within the core of the flow broke through the front. Field relationships indicate that the majority of the flows were initially emplaced as small lobes of phh-type lava that gradually changed into slabby phh and then rubbly phh through progressive disruption, shearing and compression of the surface. During its entire advance, the lava flow never reached the point of incessant surface renewal with formation of aa-type clinker, neither did it extensively develop the smooth filamentous surface common in Hawaiian phh flows. Thus, Laki lavas are intermediate flows. Microtexture analysis of samples collected along single flows will tell us what caused this evolution, such as crystallinity due to degassing or viscosity change. This flow type has been recognized on Reykjanes Peninsula in young fissure-fed lava flow-fields and in the Columbia River Basalts and Kerguelen Plateau flows. It is therefore an important component of many

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

    Science.gov (United States)

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

    2015-12-01

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

  15. Rates and processes of crystallization in on-axis and off-axis MOR basaltic melts

    Science.gov (United States)

    Zellmer, Georg F.; Dulski, Peter; Iizuka, Yoshiyuki; Perfit, Michael R.

    2012-12-01

    Residence times of olivine and plagioclase phenocrysts and xenocrysts in mid-ocean ridge (MOR) basaltic melts have been studied since the mid 1980s using geospeedometric techniques (i.e. using diffusion of major and trace elements) in order to constrain the processes of melt ascent and differentiation in this important magmatic setting. Residence times range from a few hours to several years, but potential links between these timescales and specific tectonomagmatic variables such as spreading rate and relative locations of eruption site and ridge axis have remained elusive. Here we demonstrate how incomplete chemical diffusion of Sr within plagioclase crystals from MOR basalts erupted in on- and off-axis settings on a number of ridges with variable spreading rates provide geospeedometric constraints. We combine electron probe microanalytical crystal maps with detailed laser ablation profiles of almost 70 plagioclase crystals from the fast spreading East Pacific Rise (EPR) at 9-10°N, the intermediate spreading Gorda and Juan de Fuca (JdF) ridges, and the ultraslow spreading Gakkel ridge to calculate crystal residence times. These range from a few days to several months. The scarcity of residence times exceeding years corroborates previous data indicating that most of the growth of plagioclase phenocrysts occurs within the conduit at the onset of and during eruption on the sea floor, and extends this result to the fast-spreading EPR. Further, statistical analysis is employed to show for the first time that residence times are systematically longer at slower spreading rates, in off-axis samples, and samples sourced from laterally distal axial melt lenses. Plagioclase textures and residence time variations appear to be linked to differences in the dynamics of late-stage, pre-eruptive magma storage and ascent in the different tectonomagmatic settings investigated. In the future, geospeedometric work on MOR samples will be required to assess if the effect of spreading

  16. Clay Mineralogy of Basaltic Hillsides Soils in the Western State of Santa Catarina

    Directory of Open Access Journals (Sweden)

    Jaime Antonio de Almeida

    2018-02-01

    Full Text Available ABSTRACT A commonly accepted concept holds that highly fertile, shallow soils are predominant in the Basaltic Hillsides of Santa Catarina State, in southern Brazil, but their agricultural use is restricted, either by excessive stoniness, low effective depth or steep slopes. Information about soil properties and distribution along the slopes in this region is, however, scarce, especially regarding genesis and clay fraction mineralogy. The objective of this study was to evaluate soil properties of 12 profiles distributed in three toposequences (T of the Basaltic Hillsides in the State of Santa Catarina, two located in the valley of the Peixe River (Luzerna - T1 and Ipira - T2 and one in Descanso, in the far West of the state (T3. The main focus was the mineralogical composition of the clay fraction, identified by X-ray diffractometry (XRD, and its relations with the soil chemical properties. The morphological, chemical, and mineralogical properties of the soils of the toposequences differed from each other. In most soils, the position of the most intense XRD reflections indicated predominance of kaolinite (K however, for being broad and asymmetric, a participation of interstratified kaolinite-smectite (K-S was assumed. Soils of T2 and T3, located in regions with higher temperatures, lower water surplus, and lower altitude than those of T1, were more fertile, mostly redder, and contained higher proportions of smectites (S and interstratified K-S mineral, accounting for a higher activity of the clay fraction of most soils. The T1 soils were generally less fertile, with lower clay activity and, aside from kaolinite, contained smectites with interlayered hydroxy-Al polymers (HIS. The low estimated smectite contents of the most fertile soils of all toposequences disagree with the high values of cation exchange capacity (CEC and clay activity related to pure kaolinite soils. The broad and asymmetric reflections of most of the supposed kaolinites

  17. Lithofacies characteristics of diatreme deposits: Examples from a basaltic volcanic field of SW Sardinia (Italy)

    Science.gov (United States)

    Mundula, F.; Cioni, R.; Funedda, A.; Leone, F.

    2013-04-01

    A deeply eroded diatreme field, consisting in several, decametric-sized, vertical, mainly clastic volcanic bodies of basaltic composition is described for the first time in the Variscan basement of SW Sardinia. The recognition and description of four different lithofacies in these diatremes allowed discussion of the role of the different processes which control magma eruption and conduit infilling, and making general inferences about diatremes. The studied diatremes have a cross-sectional shape from elliptical to sub-triangular, and are slightly elongated nearly parallel to the main foliation of the intruded meta-sedimentary rocks. Foliation of host rocks is locally reoriented or folded close to the contact with the diatremes, suggesting that magma possibly rose to the surface through fissures oriented nearly parallel to host rock foliation. Textural features of the volcanic bodies show many analogies with kimberlitic diatremes, despite the difference in petrography and composition. Juvenile lapilli are mainly made by ghosts of mafic phenocrysts (olivine and clinopyroxene) set in a groundmass formed by plagioclase microlites immersed in a cryptocrystalline, chlorite-rich matrix. The four lithofacies were described mainly based on the shape and physical features of the clasts and textural anisotropy: a globular, juvenile-rich, lapilli tuff facies (GJLt); an angular, juvenile-rich, lapilli tuff facies (AJLt); a lithic-rich, lapilli tuff facies LiRLt), and a coherent, lava-like facies (COH). All the clastic lithofacies are generally well sorted and typically lack a fine-grained matrix. Juvenile fragments are lapilli sized and from equant to oblate in axial ratio, and from rounded-globular to very angular in shape. Conversely, lithic clasts are largely variable in shape and size, and are mainly represented by basement-derived clasts. The absence of bedding, the scarcity of the coherent facies and the dominance of clast supported, structureless, volcaniclastic facies

  18. Preliminary Geotechnical Investigation of Two Basaltic Landslide Sites in Mauritius, Offshore Africa

    Science.gov (United States)

    Bhoopendra, D.; Fukuoka, H.; Kuwano, T.; Ichikawa, K.

    2016-12-01

    Landslide hazards in developing areas in Mauritius became a great challenge as well as a fundamental concern for the government and the citizen of the country. In recent years, landslide disasters have caused losses of both public and private properties. In 2005, a large-scale landslide at Chitrakoot affected 54 houses and infrastructures, and it was reactivated in 2006, damaging another 14 houses. Vallee Pitot landslide is frequently reactivated in these years and threatening several houses in the densely-populated zone. Being of volcanic origin, Mauritius has observed dramatic and quick weathering of the soil which may partly contribute to creating landslide-prone geo-environment. This study focuses on the preliminary geotechnical investigation of the two basaltic landslide areas in Mauritius. A recent investigation was conducted jointly by JICA (Japan International Cooperation Agency) and Ministry of Public Infrastructure and Land Transport of Government of Mauritius on both sites from 2012 to 2015 to survey the landslide surface and to implement countermeasures works.Both sites are located in the highly populated area in the capital city of Mauritius.The geological features of the sites were studied with the borehole core logging data obtained from 6 boreholes and it was found that possible sliding surface was observed in the colluvium layer consisting of gravels and stiff silty-clays, at depths from 6 to 10 m below the ground surface. The rate of landslide movement during heavy rainfall amount exceeding 100 mm/hr was elaborated with past records of extensometers installed on these sites. Colluvium samples from both sites of the same characteristics with the sliding surface were tested in the ring shear apparatus in Japan under different normal stresses reducing from 300 kPa to 50 kPa step-wise at a shear velocity of 0.02 mm/min under drained condition to obtain the residual friction angle (φ) and the cohesion (c). Obtained residual friction angle and cohesion

  19. Mineral storage of CO2/H2S gas mixture injection in basaltic rocks

    Science.gov (United States)

    Clark, D. E.; Gunnarsson, I.; Aradottir, E. S.; Oelkers, E. H.; Sigfússon, B.; Snæbjörnsdottír, S. Ó.; Matter, J. M.; Stute, M.; Júlíusson, B. M.; Gíslason, S. R.

    2017-12-01

    Carbon capture and storage is one solution to reducing CO2 emissions in the atmosphere. The long-term geological storage of buoyant supercritical CO2 requires high integrity cap rock. Some of the risk associated with CO2 buoyancy can be overcome by dissolving CO2 into water during its injection, thus eliminating its buoyancy. This enables injection into fractured rocks, such as basaltic rocks along oceanic ridges and on continents. Basaltic rocks are rich in divalent cations, Ca2+, Mg2+ and Fe2+, which react with CO2 dissolved in water to form stable carbonate minerals. This possibility has been successfully tested as a part of the CarbFix CO2storage pilot project at the Hellisheiði geothermal power plant in Iceland, where they have shown mineralization occurs in less than two years [1, 2]. Reykjavik Energy and the CarbFix group has been injecting a mixture of CO2 and H2S at 750 m depth and 240-250°C since June 2014; by 1 January 2016, 6290 tons of CO2 and 3530 tons of H2S had been injected. Once in the geothermal reservoir, the heat exchange and sufficient dissolution of the host rock neutralizes the gas-charged water and saturates the formation water respecting carbonate and sulfur minerals. A thermally stable inert tracer was also mixed into the stream to monitor the subsurface transport and to assess the degree of subsurface carbonation and sulfide precipitation [3]. Water and gas samples have been continuously collected from three monitoring wells and geochemically analyzed. Based on the results, mineral saturation stages have been defined. These results and tracer mass balance calculations are used to evaluate the rate and magnitude of CO2 and H2S mineralization in the subsurface, with indications that mineralization of carbon and sulfur occurs within months. [1] Gunnsarsson, I., et al. (2017). Rapid and cost-effective capture and subsurface mineral storage of carbon and sulfur. Manuscript submitted for publication. [2] Matter, J., et al. (2016). Rapid

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

    Science.gov (United States)

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

    2003-12-01

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

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

    Science.gov (United States)

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

    2016-12-01

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

  2. Determination of basalt physical and thermal properties at varying temperatures, pressures, and moisture contents. First progress report, fiscal year 1979

    International Nuclear Information System (INIS)

    Miller, R.J.; Bishop, R.C.

    1979-01-01

    This report is a summary of the rock mechanics testing done at the Earth Mechanics Institute of the Colorado School of Mines for Rockwell Hanford Operations under Subcontract SA-917. Cores were supplied from drill hole DC-6 on the Hanford Site, characterized geologically, and tested for thermal and physical properties for designing long-term underground storage of radioactive waste materials. This report presents the approved test procedures, results, and data analysis for this test series. Results indicated thermophysical properties similar to those of previously tested basalt cores from the Hanford area, but showed no significant trends; thus, generalizations are risky at this time. However, density was found to be a good guide to thermal and physical properties--higher density basalt cores showed significant improvements in physical and thermal properties

  3. Predicting the tensile strength of A UD basalt/ epoxy composite used for the confinement of concrete structures

    Science.gov (United States)

    Ciniņa, I.; Zīle, O.; Andersons, J.

    2013-01-01

    The principal aim of the present research was to predict the strength of UD basalt fiber/epoxy matrix composites in tension along the reinforcement direction. Tension tests on single basalt fibers were performed to determine the functional form of their strength distribution and to evaluate the parameters of the distribution. Also, microbond tests were carried out to assess the interfacial shear strength of the fibers and polymer matrix. UD composite specimens were produced and tested for the longitudinal tensile strength. The predicted strength of the composite was found to exceed the experimental values by ca. 20%, which can be explained by imperfections in the fiber alignment, impregnation, and adhesion in the composite specimens.

  4. Geologic history of quartz-normative and olivine-normative basalts in the vicinity of Hadley Rille (Apollo 15)

    International Nuclear Information System (INIS)

    Grove, T.L.

    1985-01-01

    The geologic history of the quartz normative (QNB) and olivine normative (ONB) basalt types at Hadley Rille are discussed. A model for the geology of the mare basalts was constructed from a combination of field observations, sample chemistry, sample petrology and personal bias from terrestrial experience. The model proposes that the QNBs are the only mare lava type that is present as outcrop in the area traversed by the astronauts during the Apollo 15 mission. The returned QNB samples formed during a single eruptive phase of the Hadley Rille lava tube system. The ONB lavas are an exotic component transported to the site by a cratering event, or the ONBs are samples excavated from older are bedrock that was partly covered by the QNB lavas

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

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

    2015-01-01

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