WorldWideScience

Sample records for thick komatiitic basalt

  1. The petrogenesis of Gorgona komatiites, picrites and basalts: new field, petrographic and geochemical constraints

    Science.gov (United States)

    Kerr, A. C.; Marriner, G. F.; Arndt, N. T.; Tarney, J.; Nivia, A.; Saunders, A. D.; Duncan, R. A.

    1996-04-01

    Gorgona Island, Colombia is remarkable not only because it contains the only Phanerozoic komatiites, but also because it has mafic to ultramafic lavas with a wide range of compositions, from moderately enriched to extremely depleted (relative to Bulk Earth). The komatiite flows are, in many respects similar to Archaean komatiites; they formed from MgO-rich (18%) liquids and have upper spinifex zones and lower cumulate zones. The cumulate zones of Archaean komatiites contain many solid grains, in contrast more than 90% of the olivine in the Gorgona cumulates is highly skeletal. This combined with the fact that the Gorgona cumulate zones are thinner than those in Archaean komatiites, suggests that the komatiite magma became strongly superheated en route to the surface. The komatiites have trace element contents intermediate between those of the basalts and the ultramafic tuffs. Some basalts have isotope compositions indicative of long-term enrichment in incompatible elements, whereas other basalts and ultramafic volcanics have isotopic signatures that imply corresponding depletion. It is apparent that the plume source region of the Gorgona magmas was markedly heterogeneous, with at least two source components contributing to the observed variation in composition. This heterogeneity may have resulted from the incorporation of different components into the plume source, or it may be the result of complex melting and melt extraction processes during the ascent of a heterogeneous plume. Despite earlier suggestions that there may have been a significant age gap between depleted komatiite and basalt flows and the enriched basalts, new 40Ar- 39Ar dating of basalts and gabbros are more consistent with all being generated at 87 Ma during formation of the Caribbean/Colombian plateau, possibly at the Galapagos hotspot.

  2. Re-Os systematics of komatiites and komatiitic basalts at Dundonald Beach, Ontario, Canada: Evidence for a complex alteration history and implications of a late-Archean chondritic mantle source

    Science.gov (United States)

    Gangopadhyay, Amitava; Sproule, Rebecca A.; Walker, Richard J.; Lesher, C. Michael

    2005-11-01

    Osmium isotopic compositions, and Re and Os concentrations have been examined in one komatiite unit and two komatiitic basalt units at Dundonald Beach, part of the 2.7 Ga Kidd-Munro volcanic assemblage in the Abitibi greenstone belt, Ontario, Canada. The komatiitic rocks in this locality record at least three episodes of alteration of Re-Os elemental and isotope systematics. First, an average of 40% and as much as 75% Re may have been lost due to shallow degassing during eruption and/or hydrothermal leaching during or immediately after emplacement. Second, the Re-Os isotope systematics of whole rock samples with 187Re/ 188Os ratios >1 were reset at ˜2.5 Ga, possibly due to a regional metamorphic event. Third, there is evidence for relatively recent gain and loss of Re in some rocks. Despite the open-system behavior, some aspects of the Re-Os systematics of these rocks can be deciphered. The bulk distribution coefficient for Os (D Ossolid/liquid) for the Dundonald rocks is ˜3 ± 1 and is well within the estimated D values obtained for komatiites from the nearby Alexo area and stratigraphically-equivalent komatiites from Munro Township. This suggests that Os was moderately compatible during crystal-liquid fractionation of the magmas parental to the Kidd-Munro komatiitic rocks. Whole-rock samples and chromite separates with low 187Re/ 188Os ratios (Gorgona Island, arc-related rocks and present-day ocean island basalts. This suggests that the Kidd-Munro komatiites sampled a late-Archean mantle source region that was significantly more homogeneous with respect to Re/Os relative to most modern mantle-derived rocks.

  3. Geochemistry of komatiites and basalts from the Rio das Velhas and Pitangui greenstone belts, São Francisco Craton, Brazil: Implications for the origin, evolution, and tectonic setting

    Science.gov (United States)

    Verma, Sanjeet K.; Oliveira, Elson P.; Silva, Paola M.; Moreno, Juan A.; Amaral, Wagner S.

    2017-07-01

    The Neoarchean Rio das Velhas and Pitangui greenstone belts are situated in the southern São Francisco Craton, Minas Gerais, Brazil. These greenstone belts were formed between ca. 2.79-2.73 Ga, and consist mostly of mafic to ultramafic volcanics and clastic sediments, with minor chemical sediments and felsic volcanics that were metamorphosed under greenschist facies. Komatiites are found only in the Rio das Velhas greenstone belt, which is composed of high-MgO volcanic rocks that have been identified as komatiites and high-Mg basalts, based on their distinctive geochemical characteristics. The Rio das Velhas komatiites are composed of tremolite + actinolite + serpentine + albite with a relict spinifex-texture. The Rio das Velhas komatiites have a high magnesium content ((MgO)adj ≥ 28 wt.%), an Al-undepleted Munro-type [(Al2O3/TiO2)adj and (CaO/Al2O3)adj] ratio ranging from 27 to 47 and 0.48 to 0.89, relatively low abundances of incompatible elements, a depletion of light rare earth elements (LREE), a pattern of non-fractionated heavy rare- earth elements (HREE), and a low (Gd/Yb)PM ratio (≤ 1.0). Negative Ce anomalies suggest that alteration occurred during greenschist facies metamorphism for the komatiites and high-Mg basalts. The low [(Gd/Yb)PM 18] and high HREE, Y, and Zr content suggest that the Rio das Velhas komatiites were derived from the shallow upper mantle without garnet involvement in the residue. The chemical compositions [(Al2O3/TiO2)adj, (FeO)adj, (MgO)adj, (CaO/Al2O3)adj, Na, Th, Ta, Ni, Cr, Zr, Y, Hf, and REE] indicate that the formation of the komatiites, high-Mg basalts and basalts occurred at different depths and temperatures in a heterogeneous mantle. The komatiites and high-Mg basalts melted at liquidus temperatures of 1450-1550 °C. The Pitangui basalts are enriched in the highly incompatible LILE (large-ion lithophile elements) relative to the moderately incompatible HFS (high field strength) elements. The Zr/Th ratio ranging from 76 to

  4. Origin of the Permian-Triassic komatiites, northwestern Vietnam

    Science.gov (United States)

    Hanski, Eero; Walker, Richard J.; Huhma, Hannu; Polyakov, Gleb V.; Balykin, Pavel A.; Tran Trong Hoa; Ngo Thi Phuong

    Rare examples of Phanerozoic komatiites are found in the Song Da zone, NW Vietnam. These komatiites were erupted through continental crust and may belong to the SE extension of the Permo-Triassic Emeishan volcanic province located in SW China. They provide a good opportunity to study the source characteristics of starting plume magmas in a continental flood basalt province. Erupted on late-Permian carbonate rocks, the komatiitic rocks are interbedded with low-Ti olivine basalts. Basaltic komatiites display pyroxene spinifex textures, while more magnesian rocks (MgO up to 32 wt.%) are porphyritic, containing a single, cognate population of euhedral to elongated olivine phenocrysts with Fo up to 93.0%. This suggests a highly magnesian parental magma with 22-23 wt.% MgO. In terms of major and minor elements, the komatiites are similar to the ca. 89 Ma old Gorgona Island komatiites of Colombia. The Song Da komatiites are also strongly light-rare-earth-element- (LREE) depleted (CeN/YbN 0.30-0.62) and have unfractionated heavy rare earth element (HREE) patterns. The komatiites have high Os concentrations (up to 7.0 ppb), low but variable Re/Os ratios, and define an isochron with an age of 270+/-21 Ma, and an initial 188Os/187Os ratio of 0.12506+/- 0.00041 (γOs=+0.02+/-0.40). The Os isotopic systematics of the komatiites show no effects of crustal contamination. In contrast, their initial ɛNd values range from +3 to +8, reflecting varying but generally small degrees of contamination with Proterozoic sialic basement material. Associated low-Ti basalts have low initial ɛNd values (-0.8 to -7.5), high initial γOs values (>=15), flat or LREE-enriched REE patterns, and Nb-Ta depletion. These characteristics are also attributed to variable extents of crustal contamination.

  5. Petrology and geochemistry of komatiites and tholeiites from Gorgona Island, Colombia

    Science.gov (United States)

    Aitken, Bruce G.; Echeverría, Lina M.

    1984-04-01

    Komatiitic rocks from Gorgona Island, Colombia, in contrast to their Archaean counterparts, occur as rather structureless flows. In addition, textural and mineralogical features indicate that the Gorgona komatiites may have crystallized from superheated liquids. Komatiitic rocks have MgO contents which range from 24 to 11 wt.% and plot on well-defined olivine (Fo90) control lines. Calculations show that potential evolved liquids (MgO<11 wt%) will be SiO2-poor. Komatiites, in this case, cannot be regarded as parental to the associated tholeiitic basalt sequence. On the basis of REE concentrations and Sr, Nd isotopic compositions, the associated basalts are found to be of two types. One type (K-tholeiite) is characterized by noticeably fractionated REE patterns and relatively primitive isotopic compositions similar to those of the komatiites. K-tholeiites, together with komatiites, are regarded as comprising a distinctive komatiitic suite. REE patterns within this suite show progressive depletion in the LREE from K-tholeiites to komatiites, and represent increasingly higher degrees of melting of the same mantle source region. The other type (T-tholeiite), representative of the bulk of the exposed basalt sequence, has flat REE patterns and relatively evolved isotopic compositions. This tholeiitic suite is clearly genetically unrelated to the komatiitic suite.

  6. Phase equilibrium constraints on the origin of basalts, picrites, and komatiites

    Science.gov (United States)

    Herzberg, C.; O'Hara, M. J.

    1998-07-01

    Experimental phase equilibrium studies at pressures ranging from 1 atm to 10 GPa are sufficient to constrain the origin of igneous rocks formed along oceanic ridges and in hotspots. The major element geochemistry of MORB is dominated by partial crystallization at low pressures in the oceanic crust and uppermost mantle, forcing compliance with liquid compositions in low-pressure cotectic equilibrium with olivine, plagioclase and often augite too; parental magmas to MORB formed by partial melting, mixing, and pooling have not survived these effects. Similarly, picrites and komatiites can transform to basalts by partial crystallization in the crust and lithosphere. However, parental picrites and komatiites that were successful in erupting to the surface typically have compositions that can be matched to experimentally-observed anhydrous primary magmas in equilibrium with harzburgite [L+Ol+Opx] at 3.0 to 4.5 GPa. This pressure is likely to represent an average for pooled magmas that collected at the top of a plume head as it flattened below the lithosphere. There is substantial uniformity in the normative olivine content of primary magmas at all depths in a plume melt column, and this results in pooled komatiitic magmas that are equally uniform in normative olivine. However, the imposition of pressure above 3 GPa produces picrites and komatiites with variations in normative enstatite and Al 2O 3 that reveal plume potential temperature and depths of initial melting. Hotter plumes begin to melt deeper than cooler plumes, yielding picrites and komatiites that are enriched in normative enstatite and depleted in Al 2O 3 because of a deeper column within which orthopyroxene can dissolve during decompression. Pressures of initial melting span the 4 to 10 GPa range, increasing in the following order: Iceland, Hawaii, Gorgona, Belingwe, Barberton. Parental komatiites and picrites from a single plume also exhibit internal variability in normative enstatite and Al 2O 3

  7. Dynamic melting in plume heads: the formation of Gorgona komatiites and basalts

    Science.gov (United States)

    Arndt, Nicholas T.; Kerr, Andrew C.; Tarney, John

    1997-01-01

    The small Pacific island of Gorgona, off the coast of Colombia, is well known for its spectacular spinifex-textured komatiites. These high-Mg liquids, which have been linked to a late Cretaceous deep mantle plume, are part of a volcanic series with a wide range of trace-element compositions, from moderately enriched basalts ( La/SmN ˜ 1.5) to extremely depleted ultramafic tuffs and picrites ( La/SmN ˜ 0.2). Neither fractional crystallization, nor partial melting of a homogeneous mantle source, can account for this large variation: the source must have been chemically heterogeneous. Low 143Nd/144Nd in the more enriched basalts indicates some initial source heterogeneity but most of the variation in magma compositions is believed to result from dynamic melting during the ascent of a plume. Modelling of major- and trace-element compositions suggests that ultramafic magmas formed at ˜ 60-100 km depth, and that the melt extraction that gave rise to their depleted sources started at still greater depths. The ultra-depleted lavas represent magmas derived directly from the hottest, most depleted parts of the plume; the more abundant moderately depleted basalts are interpreted as the products of pooling of liquids from throughout the melting region.

  8. Evidence for komatiite-type lavas on Mars from Phobos ISM data and other observations

    Science.gov (United States)

    Reyes, David P.; Christensen, Philip R.

    1994-01-01

    Data from the Phobos 2 Imaging Spectrometer for Mars (ISM), compiled by Mustard et al. (1993), and other observations support the existence of komatiitic lavas on Mars. Mustard et al. (1993) determined from ISM data that the composition of the low-albedo materials covering the Syrtis Major plateau originally consisted of augite-bearing basalt containing both augite and pigeonite, with no appreciable amount of olivine. This description is consistent with a komatiitic basalt. Komatiite is significant for the Earth because it contains a high amount of MgO, implying generation under unique circumstances compared to more typical basaltic compositions and may be similarly important for Mars.

  9. The Fe-Rich Clay Microsystems in Basalt-Komatiite Lavas: Importance of Fe-Smectites for Pre-Biotic Molecule Catalysis During the Hadean Eon

    Science.gov (United States)

    Meunier, Alain; Petit, Sabine; Cockell, Charles S.; El Albani, Abderrazzak; Beaufort, Daniel

    2010-06-01

    During the Hadean to early Archean period (4.5-3.5 Ga), the surface of the Earth’s crust was predominantly composed of basalt and komatiite lavas. The conditions imposed by the chemical composition of these rocks favoured the crystallization of Fe-Mg clays rather than that of Al-rich ones (montmorillonite). Fe-Mg clays were formed inside chemical microsystems through sea weathering or hydrothermal alteration, and for the most part, through post-magmatic processes. Indeed, at the end of the cooling stage, Fe-Mg clays precipitated directly from the residual liquid which concentrated in the voids remaining in the crystal framework of the mafic-ultramafic lavas. Nontronite-celadonite and chlorite-saponite covered all the solid surfaces (crystals, glass) and are associated with tiny pyroxene and apatite crystals forming the so-called “mesostasis”. The mesostasis was scattered in the lava body as micro-settings tens of micrometres wide. Thus, every square metre of basalt or komatiite rocks was punctuated by myriads of clay-rich patches, each of them potentially behaving as a single chemical reactor which could concentrate the organics diluted in the ocean water. Considering the high catalytic potentiality of clays, and particularly those of the Fe-rich ones (electron exchangers), it is probable that large parts of the surface of the young Earth participated in the synthesis of prebiotic molecules during the Hadean to early Archean period through innumerable clay-rich micro-settings in the massive parts and the altered surfaces of komatiite and basaltic lavas. This leads us to suggest that Fe,Mg-clays should be preferred to Al-rich ones (montmorillonite) to conduct experiments for the synthesis and the polymerisation of prebiotic molecules.

  10. Tertiary or Mesozoic komatiites from Gorgona Island, Colombia: Field relations and geochemistry

    Science.gov (United States)

    Echeverría, Lina M.

    1980-08-01

    An exceptional occurrence of ultramafic lavas within the volcanic member of the Mesozoic (or younger) Gorgona Igneous Complex represents the first known komatiites of post-Precambrian age. Gorgona komatiites are virtually unaltered and display typical spinifex textures, with 7 10 cm long plates of olivine (Fo 88 to 91) surrounded by acicular aluminous augite, subordinate plagioclase (An 56 to 78), basaltic glass, and two spinel phases. The MgO contents of the komatiites range from 15 to 22 wt.%. Sr and Nd isotopic compositions are indicative of depletion of incompatible elements in the mantle source region, as is the case for “normal” mid-ocean ridge basalts. The komatiites are low in total REE abundances and extremely depleted in LREE. They represent primary melts generated by high degree of partial melting of the mantle. Eruption temperatures are estimated at 1,450° to 1,500° C.

  11. CO 2-rich komatiitic melt inclusions in Cr-spinels within beach sand from Gorgona Island, Colombia

    Science.gov (United States)

    Shimizu, Kenji; Shimizu, Nobumichi; Komiya, Tsuyoshi; Suzuki, Katsuhiko; Maruyama, Shigenori; Tatsumi, Yoshiyuki

    2009-10-01

    The volatile content of komatiite is a key to constrain the thermal and chemical evolution of the deep Earth. We report the volatile contents with major and trace element compositions of ~ 80 melt inclusions in chromian spinels (Cr-spinels) from beach sands on Gorgona Island, Colombia. Gorgona Island is a ~ 90 Ma volcanic island, where picrites and the youngest komatiites known on the Earth are present. Melt inclusions are classified into three types on the basis of their host Cr-spinel compositions: low Ti (P type), high Ti with high Cr # (K1 type) and high Ti with low Cr # (K2 type). Chemical variations of melt inclusions in the Cr-spinels cover all of the island's lava types. P-type inclusions mainly occur in the picrites, K1-type in high-TiO 2 komatiites (some enriched basalts: E-basalts) and K2-type in low-TiO 2 komatiites. The H 2O and CO 2 contents of melt inclusions within Cr-spinels from the beach sand are highly variable (H 2O: 0.03-0.9 wt.%; CO 2: 40-4000 ppm). Evaluation of volatile content is not entirely successful because of compositional alterations of the original melt by degassing, seawater/brine assimilation and post-entrapment modification of certain elements and volatiles. However, the occurrence of many melt inclusions with low H 2O/K 2O ratios indicates that H 2O/K 2O of Gorgona komatiite is not much different from that of modern mid-oceanic ridge basalt (MORB) or oceanic island basalt. Trend of CO 2/Nb and Zr/Y ratios, accounted for by two-component mixing between the least degassed primary komatiite and low-CO 2/Nb evolved basalt, allow us to estimate a primary CO 2/Nb ratio of 4000 ± 2200 or a CO 2 content of 0.16 ± 0.09 wt.%. The determined CO 2/Nb ratio is unusually high, compared to that of MORB (530). Although the presence of CO 2 in the Gorgona komatiite does not affect the magma generation temperature, CO 2 degassing may have contributed to the eruption of high-density magmas. High CO 2/Nb and the relatively anhydrous nature of

  12. Depth and degree of melting of komatiites

    Science.gov (United States)

    Herzberg, Claude

    1992-04-01

    High pressure melting experiments have permitted new constraints to be placed on the depth and degree of partial melting of komatiites. Komatiites from Gorgona Island were formed by relatively low degrees of pseudoinvariant melting involving L + Ol + Opx + Cpx + Gt on the solidus at 40 kbar, about 130 km depth. Munro-type komatiites were separated from a harzburgite residue (L + Ol + Opx) at pressures that were poorly constrained, but were probably around 50 kbar, about 165 km depth; the degree of partial melting was less than 40 percent. Secular variations in the geochemistry of komatiites could have formed in response to a reduction in the temperature and pressure of melting with time. The 3.5 Ga Barberton komatiites and the 2.7 Ga Munro-type komatiities could have formed in plumes that were hotter than the present-day mantle by 500 deg and 300 deg, respectively. When excess temperatures are this size, melting is deeper and volcanism changes from basaltic to momatiitic. The komatiities from Gorgona Island, which are Mesozoic in age, may be representative of komatiities that are predicted to occur in oceanic plateaus of Cretaceous age throughout the Pacific (Storey et al., 1991).

  13. 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.

  14. The temperature of primary melts and mantle sources of komatiites, OIBs, MORBs and LIPs

    Science.gov (United States)

    Sobolev, Alexander

    2015-04-01

    There is general agreement that the convecting mantle, although mostly peridotitic in composition, is compositionally and thermally heterogeneous on different spatial scales. The amount, sizes, temperatures and compositions of these heterogeneities significantly affect mantle dynamics because they may diverge greatly from dominant peridotites in their density and fusibility. Differences in potential temperature and composition of mantle domains affect magma production and cannot be easily distinguished from each other. This has led to radically different interpretations of the melting anomalies that produce ocean-island basalts, large igneous provinces and komatiites: most scientists believe that they originate as hot, deep-sourced mantle plumes; but a small though influential group (e.g. Anderson 2005, Foulger, 2010) propose that they derive from high proportions of easily fusible recycled or delaminated crust, or in the case of komatiites contain large amount of H2O (e.g. Grove & Parman, 2004). The way to resolve this ambiguity is an independent estimation of temperature and composition of mantle sources of various types of magma. In this paper I report application of newly developed olivine-spinel-melt geothermometers based on partition of Al, Cr, Sc and Y for different primitive lavas from mid-ocean ridges, ocean-island basalts, large igneous provinces and komatiites. The results suggest significant variations of crystallization temperature for the same Fo of high magnesium olivines of different types of mantle-derived magmas: from the lowest (down to 1220 degree C) for MORB to the highest (up to over 1500 degree C) for komatiites and Siberian meimechites. These results match predictions from Fe-Mg olivine-melt equilibrium and confirm the relatively low temperature of the mantle source of MORB and higher temperatures in the mantle plumes that produce the OIB of Iceland, Hawaii, Gorgona, Archean komatiites and several LIPs (e.g Siberian and NAMP). The

  15. Origin of Tungsten Excess in Komatiites

    Science.gov (United States)

    Becker, H.; Brandon, A. D.; Walker, R. J.

    2004-12-01

    The limited database available for W abundances in komatiites (n=7, Newsom et al., 1996) suggests that when melting and fractional crystallization effects are filtered out, these komatiites have about 10 times higher W, compared to other mantle-derived mafic-ultramafic magmas (MORB, OIB). The excess of W in the komatiites relative to lithophile highly incompatible elements becomes obvious when compared with the low concentrations of the light REE Ce and Nd (about 1-2 ug/g in many komatiites, compared to > 10 ug/g in most MORB and OIB). In order to increase the komatiite W database, komatiite samples from Phanerozoic (Gorgona Island) and Archean terraines (Boston Creek/Canada, Belingwe/South Africa, 2.7 Ga) were dissolved and W was separated in order to obtain W concentrations by isotope dilution. Except for one sample from Gorgona Island with low W (23 ng/g), samples from all three locales show high W (516 to 2643 ng/g), with most samples containing near 700 ng/g W. Three Hawaiian picrites (H23, LO-02-04, MK-1-6) were also analyzed for comparative purposes and contain 75, 163 and 418 ng/g W, respectively. The W concentrations in the Hawaiian picrites are comparable or lower than W concentrations in Hawaiian tholeiites (Newsom et al., 1996). Mass balance considerations suggest that it is unlikely that the W excess in komatiites reflects W contributions to the mantle sources of komatiites from the outer core. The W enrichment could result from shallow-level alteration processes if primary W abundances of komatiites were low and W was added via fluids, containing W and other fluid-mobile elements derived from crustal rocks. Because most W in such samples would be of crustal origin, small contributions from the outer core may be difficult to detect using 182W systematics (Schersten et al., 2003).

  16. A SIMS study of lunar 'komatiitic glasses' - Trace element characteristics and possible origin

    Science.gov (United States)

    Shearer, C. K.; Papike, J. J.; Galbreath, K. C.; Wentworth, S. J.; Shimizu, N.

    1990-01-01

    In Apollo 16 regolith breccias, Wentworth and McKay (1988) identified a suite of minute (less than 120 microns) 'komatiitic glass beads'. The wide major element compositional range, and ultra-Mg-prime character of the glasses suggest a variety of possible origins from complex impact processes to complex volcanic processes involving rather unusual and primitive magmatism. The extent of trace element depletion or enrichment in these glasses appears to be correlated to the siderophile character of the element (ionization potential or experimentally determined silicate melt/Fe metal partition coefficients. The ultra-Mg-prime glasses are depleted in Co relative to a bulk Moon Mg/Co exhibited by many lunar samples (volcanic glasses, basalts, regolith breccia, estimated upper mantle). The low Co and high incompatible element concentrations diminish the possibility that these glasses are a product of lunar komatiitic volcanism or impact, excavation, and melting of a very high Mg-prime plutonic unit.

  17. Static Compression of Hydrous Komatiite Liquid

    Science.gov (United States)

    Agee, C. B.

    2005-12-01

    High pressure sink/float experiments have been performed on komatiite with 3 and 10 wt% added H2O in order to investigate the effect of water on magma density at high pressure and to determine if density crossovers between equilibrium olivine and hydrous komatiite can exist in the upper mantle. The starting composition komatiite, from Munro Township, with MgO=28 wt%, has been previously studied using sink/float experiments under anhydrous conditions up to 9.3 GPa (Agee and Walker, 1988, 1993). In the present study the starting material mechanical mixtures consisted of powdered komatiite, brucite, fayalite, and reagent oxides of SiO2, Al203, and CaO. Samples were contained in compression-sealed molybdenum capsules. Sink/float marker spheres implemented were gem quality synthetic forsterite (Fo100) and San Carlos olivine (Fo90). Experimental run times were 30 seconds, thus minimizing sphere-liquid reactions and liquid reaction with capsule and pressure media. All experiments were carried out in a Walker multi-anvil apparatus at the Institute of Meteoritics, University of New Mexico. The komatiite + 3 wt% H2O liquid density was bracketed at 1900-1950°C by a float of Fo100 at 7 GPa and a sink at 6 GPa. Neutral buoyancy of Fo100 was observed at 6.4 GPa. An additional neutral buoyancy of Fo90 was observed at 9 GPa. These preliminary results suggest that a density crossover between equilibrium olivine (Fo93) and hydrous komatiite with up to 3 wt% H2O can exist in the mantle, thus lending support to the water filter hypothesis for the region above the 410 km discontinuity (Bercovici and Karato, 2003). Our results for static compression of komatiite + 3 wt% H2O are in good agreement with diamond sink/float observations by Sakamaki et al.(2005) on MORB + 2 wt% H2O. Our komatiite + 10 wt% H2O liquid density measurements are still in progress; however, flotation of Fo100 has not been observed in these experiments up to 9.2 GPa.

  18. Komatiites and nickel sulphide orebodies of the Black Swan area, Yilgarn Craton, Western Australia. 1. Petrology and volcanology of host rocks

    Science.gov (United States)

    Hill, R. E. T.; Barnes, S. J.; Dowling, S. E.; Thordarson, T.

    2004-11-01

    The Black Swan Succession is a bimodal association of dacitic and komatiitic volcanic rocks located about 50 km NNE of Kalgoorlie, within the 2.7-Ga Eastern Goldfields greenstone province of the Yilgarn Craton. The komatiite stratigraphy comprises a steep dipping, east facing package about 700 m in maximum thickness and about 2.5 km in strike length (Fig. 1), which hosts a number of economically exploitable Ni sulphide orebodies including the Silver Swan massive ore shoot (approximately half a million tonnes at about 10.5% Ni). The sequence can be subdivided into a Lower Felsic Unit, comprising coherent and autobrecciated facies of multiple dacite lava flows; an upper Eastern and lower Western Ultramafic Unit, each showing marked lateral facies variation, and an Upper Felsic Unit coeval with the Eastern Ultramafic Unit. The komatiite sequence has been metamorphosed at sub-greenschist facies in the presence of high proportions of CO2-rich fluid, giving rise to pervasive talc carbonate and talc carbonate quartz assemblages, with extensive preservation of pseudomorphed igneous textures. Cores of lizardite serpentinite are present in the thickest parts of the ultramafic succession. The degree of penetrative deformation is generally very low, and original stratigraphic relationships are largely intact in much of the sequence. The Eastern Ultramafic Unit and Western Ultramafic Unit are interpreted as components of a single large komatiite flow field, representing overlapping stages in the emplacement of a series of distributory lava pathways and flanking sheet flows. The Western Ultramafic Unit which hosts the bulk of the high-grade massive and disseminated ores is a sequence dominated by coarse-grained olivine cumulates, 2 km wide and up to 500 m thick, with major magma pathways represented by thick, homogenous olivine mesocumulate piles at its northern and southern ends: respectively 400 and 200 m thick. The sequence between the two major pathways consists of olivine

  19. Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

    Science.gov (United States)

    Saha, Abhishek; Manikyamba, C.; Santosh, M.; Ganguly, Sohini; Khelen, Arubam C.; Subramanyam, K. S. V.

    2015-06-01

    High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ΣPGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir

  20. Boron isotopic composition of olivine-hosted melt inclusions from Gorgona komatiites, Colombia: New evidence supporting wet komatiite origin

    Science.gov (United States)

    Gurenko, Andrey A.; Kamenetsky, Vadim S.

    2011-12-01

    A fundamental question in the genesis of komatiites is whether these rocks originate from partial melting of dry and hot mantle, 400-500 °C hotter than typical sources of MORB and OIB magmas, or if they were produced by hydrous melting of the source at much lower temperatures, similar or only moderately higher than those known today. Gorgona Island, Colombia, is a unique place where Phanerozoic komatiites occur and whose origin is directly connected to the formation of the Caribbean Large Igneous Province. The genesis of Gorgona komatiites remains controversial, mostly because of the uncertain origin of volatile components which they appear to contain. These volatiles could equally result from shallow level magma contamination, melting of a "damp" mantle or fluid-induced partial melting of the source due to devolatilization of the ancient subducting plate. We have analyzed boron isotopes of olivine-hosted melt inclusions from the Gorgona komatiites. These inclusions are characterized by relatively high contents of volatile components and boron (0.2-1.0 wt.% H 2O, 0.05-0.08 wt.% S, 0.02-0.03 wt.% Cl, 0.6-2.0 μg/g B), displaying positive anomalies in the overall depleted, primitive mantle (PM) normalized trace element and REE spectra ([La/Sm] n = 0.16-0.35; [H 2O/Nb] n = 8-44; [Cl/Nb] n = 27-68; [B/Nb] n = 9-30, assuming 300 μg/g H 2O, 8 μg/g Cl and 0.1 μg/g B in PM; Kamenetsky et al., 2010. Composition and temperature of komatiite melts from Gorgona Island constrained from olivine-hosted melt inclusions. Geology 38, 1003-1006). The inclusions range in δ11B values from - 11.5 to + 15.6 ± 2.2‰ (1 SE), forming two distinct trends in a δ11B vs. B-concentration diagram. Direct assimilation of seawater, seawater-derived components, altered oceanic crust or marine sediments by ascending komatiite magma cannot readily account for the volatile contents and B isotope variations. Alternatively, injection of < 3wt.% of a 11B enriched fluid to the mantle source could

  1. Viscosity of komatiite liquid at high pressure and temperature

    Science.gov (United States)

    O Dwyer, L.; Lesher, C. E.; Wang, Y.

    2006-12-01

    The viscosities of komatiite liquids at high pressures and temperatures are being investigated by the in-situ falling sphere technique, using the T-25 multianvil apparatus at the GSECARS 13 ID-D beamline at the Advanced Photon Source, ANL. The refractory and fluid nature of komatiite and other ultramafic liquids relevant to the Earth's deep interior, presents unique challenges for this approach. To reach superliquidus temperatures we use a double reservoir configuration, where marker spheres are placed at the top of both a main melt reservoir and an overlying reservoir containing a more refractory composition. Using this approach, we have successfully measured the viscosity of a komatiite from Gorgona Island (GOR-94-29; MgO - 17.8 wt.%; NBO/T = 1.6) up to 6 GPa and 1900 K. Under isothermal conditions, viscosity increases with pressure, consistent with the depolymerized nature of the komatiite. At 1900 K, viscosity increases from 1.5 (+- 0.3) Pa s at 3.5 GPa to 3.4 (+- 0.3) Pa s at 6 GPa, corresponding to an activation volume of 2.2 cm3/mol. At high pressures, the viscosities of Gorgona Island komatiite melt are an order of magnitude higher than those measured by Liebske et al. (2005, EPSL, v. 240) for peridotite melt (MgO 37.1 wt.%; NBO/T = 2.5), and similar in magnitude to molten diopside (NBO/T = 2) (Reid et al. 2003, PEPI, v. 139). The positive pressure dependence is consistent with the reduction in interatomic space diminishing the free volume of the liquid as it is compressed. Above 6 GPa the free volume reduction may become less important with the production of high-coordinated network formers, as attributed to the reversal of the pressure dependence of viscosity for peridotite melt at ~8.5 GPa and diopside melt at ~10 GPa. Experiments at higher pressures are underway to determine if a similar viscosity maximum occurs for komatiite melt and whether its pressure is greater than 10 GPa, as suggested by the data for peridotite and diopside melts.

  2. Volatile-rich komatiitic and picritic melt inclusions in Cr-spinel beach sand from Gorgona Island, Colombia

    Science.gov (United States)

    Shimizu, K.; Shimizu, N.; Suzuki, K.; Tatsumi, Y.; Komiya, T.; Maruyama, S.

    2007-12-01

    Volatile content of komatiite is a key to constrain thermal evolution of the deep Earth. We report volatile contents with major and trace element compositions of melt inclusions (MIs) in chromian spinel (Cr-spinel) from beach sands of Gorgona Island, Colombia. Gorgona Island is ~90 Ma volcanic island, where picrites and the world-youngest komatiites occur. As Cr-spinel is dense and rigid oxide mineral that crystallizes only at early stages of crystallization, it is considered to be a superior container for retaining primitive melt, even including volatiles. Volatile (H2O, CO2, S, F and Cl) and trace element (K2O, Sr, Y, Zr, Nb, Ba, La, Ce, Sm, Dy, Yb) compositions of ~80 MIs were analyzed by SIMS (Cameca-1280 and 3f, respectively) at WHOI. MIs in the Cr-spinel from Gorgona Is. are classified into three types by their host Cr-spinel compositions such as low-Ti (P-type), high-Ti with high-Cr# (BK-type) and high-Ti with low-Cr# (K-type). MIs of P-type, BK-type and K-type are mostly in compositional ranges of picrite, high TiO2 komatiite (some basalt) and low TiO2 komatiite in Gorgona Island, respectively. Water content of P-type MIs is variable, ranging from 0.05 to 0.9 wt%, whereas those of BK and K-type MIs are limited (500 ppm) do not contain (shrinkage) bubbles and many of them are low in K2O. H2O/K2O, CO2/K2O, S/K2O and F/K2O ratios are positively correlated with Y/Sr ratios, indicating degassing trends of melt at crystallization, magma mixing and/or assimilation. Undegassed H2O/K2O, CO2/K2O, S/K2O and F/K2O ratios of komatiitic (picritic) melt are estimated to be ~10 (~40), ~80 (n.d.), ~7(~3) and ~1(~0.5), respectively, which are much higher than those estimated for the depleted source mantle of the MORB [1.6, 0.7, 1.6 and 0.2, respectively; Salters, V. & Stracke, A. (2004), Composition of the depleted mantle. Geochem. Geophys. Geosys. 5 (2003GC000597)]. The results suggest that Gorgona komatiite and picrite magmas were derived from volatile-rich sources. CO2

  3. Noble metal abundances in komatiite suites from Alexo, Ontario and Gorgona Island, Colombia

    Science.gov (United States)

    Brügmann, G. E.; Arndt, N. T.; Hofmann, A. W.; Tobschall, H. J.

    1987-08-01

    The distribution of the chalcophile and siderophile metals Cu, Ni, Au, Pd, Ir, Os and Ru in an Archaean komatiite flow from Alexo, Ontario and in a Phanerozoic komatiitic suite of Gorgona Island, Colombia, provides new information about the geochemical behaviour of these elements. Copper, Au and Pd behave as incompatible elements during the crystallization of these ultramafic magmas. In contrast, Ni, Ir, Os and Ru concentrations systematically decrease with decreasing MgO contents, a pattern characteristic of compatible elements. These trends are most probably controlled by olivine crystallization, which implies that Ir, Os and Ru are compatible in olivine. Calculated partition coefficients for Ir, Os and Ru between olivine and the melt are about 1.8. Compared to primitive mantle, parental komatiitic liquids are enriched in (incompatible) Cu, Au and Pd and depleted in (compatible) Ir, Os and Ru. Within both Archaean and Phanerozoic komatiites, noble metal ratios such as Au/Pd, Ir/Os, Os/Ru and Ru/Ir and ratios of lithophile and siderophile elements such as Ti/Pd, Ti/Au are constant and similar to primitive mantle values. This implies that Au and Pd are moderately incompatible elements and that there has been no significant fractionation of siderophile and lithophile elements since the Archaean. Platinum-group element abundances of normal MORB are highly variable and always much lower than in komatiites, because MORB magma is saturated with sulfur and a variable but minor amount of sulfide segregated during mantle melting or during the ascent of magma to the surface. Sulfide deposits associated with komatiites display similar chalcophile element patterns to those of komatiites. Noble metal ratios such as Pd/Ir, Au/Ir, Pd/Os and Pd/Ru can be used to determine the composition of the host komatiite at the time of sulfide segregation.

  4. Are oceanic plateaus sites of komatiite formation?

    Science.gov (United States)

    Storey, M.; Mahoney, J. J.; Kroenke, L. W.; Saunders, A. D.

    1991-04-01

    During Cretaceous and Tertiary time a series of oceanic terranes were accreted onto the Pacific continental margin of Colombia. The island of Gorgona is thought to represent part of the most recent, early Eocene, terrane-forming event. Gorgona is remarkable for the occurrence of komatiites of middle Cretaceous age, having MgO contents up to 24%. The geochemistry of spatially and temporally associated tholeiites suggests that Gorgona is an obducted fragment of the oceanic Caribbean Plateau, postulated by Duncan and Hargraves (1984) to have formed at 100 to 75 Ma over the Galapagos hotspot. Further examples of high-MgO oceanic lavas that may represent fragments of the Caribbean Plateau occur in allochthonous terranes on the island of Curaçao in the Netherlands Antilles and in the Romeral zone ophiolites in the southwestern Colombian Andes. These and other examples suggest that the formation of high-MgO liquids may be a feature of oceanic-plateau settings. The association of Phanerozoic komatiites with oceanic plateaus, coupled with thermal considerations, provides a plausible analogue for the origin of some komatiite-tholeiite sequences in Archean greenstone belts.

  5. Komatiites and nickel sulfide ores of the Black Swan area, Yilgarn Craton, Western Australia. 3: Komatiite geochemistry, and implications for ore forming processes

    Science.gov (United States)

    Barnes, Stephen J.; Hill, Robin E. T.; Evans, Noreen J.

    2004-11-01

    The Black Swan komatiite sequence is a package of dominantly olivine-rich cumulates with lesser volumes of spinifex textured rocks, interpreted as a section through an extensive komatiite lava flow field. The sequence hosts a number of nickel sulfide orebodies, including the Silver Swan massive shoot and the Cygnet and Black Swan disseminated orebodies. A large body of whole rock analyses on komatiitic rocks from the Black Swan area has been filtered for metasomatic effects. With the exception of mobile elements such as Ca and alkalis, most samples retain residual igneous geochemistry, and can be modelled predominantly by fractionation and accumulation of olivine. Whole rock MgO FeO relationships imply a relatively restricted range of olivine compositions, more primitive than the olivine which would have been in equilibrium with the transporting komatiite lavas, and together with textural data indicate that much of the cumulus olivine in the sequence was transported. Flow top compositions show evidence for chromite saturation, but the cumulates are deficient in accumulated chromite. Chromite compositions are typical of those found in compound flow-facies komatiites, and are distinct from those in komatiitic dunite bodies. Incompatible trace element abundances show three superimposed influences: control by the relative proportion of olivine to liquid; a signature of crustal contamination and an overprint of metasomatic introduction of LREE, Zr and Th. This overprint is most evident in cumulates, and relatively insignificant in the spinifex rocks. Platinum and palladium behaved as incompatible elements and are negatively correlated with MgO. They show no evidence for wholesale depletion due to sulfide extraction, which was evidently restricted to specific lava tubes or pathways. The lack of correspondence between PGE depletion and contamination by siliceous material implies that contamination alone is insufficient to generate S-saturation and ore formation in the

  6. Archaean ultra-depleted komatiites formed by hydrous melting of cratonic mantle.

    Science.gov (United States)

    Wilson, A H; Shirey, S B; Carlson, R W

    2003-06-19

    Komatiites are ultramafic volcanic rocks containing more than 18 per cent MgO (ref. 1) that erupted mainly in the Archaean era (more than 2.5 gigayears ago). Although such compositions occur in later periods of Earth history (for example, the Cretaceous komatiites of Gorgona Island), the more recent examples tend to have lower MgO content than their Archaean equivalents. Komatiites are also characterized by their low incompatible-element content, which is most consistent with their generation by high degrees of partial melting (30-50 per cent). Current models for komatiite genesis include the melting of rock at great depth in plumes of hot, diapirically rising mantle or the melting of relatively shallow mantle rocks at less extreme, but still high, temperatures caused by fluxing with water. Here we report a suite of ultramafic lava flows from the Commondale greenstone belt, in the southern part of the Kaapvaal Craton, which represents a previously unrecognized type of komatiite with exceptionally high forsterite content of its igneous olivines, low TiO(2)/Al(2)O(3) ratio, high silica content, extreme depletion in rare-earth elements and low Re/Os ratio. We suggest a model for their formation in which a garnet-enriched residue left by earlier cratonic volcanism was melted by hydration from a subducting slab.

  7. Geologic structure of the eastern mare basins. [lunar basalts

    Science.gov (United States)

    Dehon, R. A.; Waskom, J. D.

    1976-01-01

    The thickness of mare basalts in the eastern maria are estimated and isopachs of the basalts are constructed. Sub-basalt basin floor topography is determined, and correlations of topographic variations of the surface with variations in basalt thickness or basin floor topography are investigated.

  8. Pressure Dependence of Komatiite Liquid Viscosity and Implications for Magma Ocean Rheology

    Science.gov (United States)

    O'Dwyer Brown, L.; Lesher, C. E.; Terasaki, H. G.; Yamada, A.; Sakamaki, T.; Shibazaki, Y.; Ohtani, E.

    2009-12-01

    The viscosities of komatiite liquids at high pressures and temperatures were investigated using the in-situ falling sphere technique at BL04B1, SPring-8. Komatiites are naturally occurring magmas, rich in network modifying cations. Despite the refractory and fluid nature of komatiite, we successfully measured the viscosity of molten komatiites from Gorgona Island, Colombia (MgO = 17.8 wt.%; NBO/T = 1.5) between 11 and 13 GPa at 2000 C, and from Belingwe, Zimbabwe (MgO = 28.14 wt.%; NBO/T = 2.1) from 12 to 14 GPa at 2000 C. Under isothermal conditions, the viscosity of Gorgona Island komatiite melt increased with pressure, consistent with our previous measurements at lower pressures for this composition. We interpreted this positive pressure dependence as the result of reductions in interatomic space diminishing the free volume of the liquid when compressed. The viscosity of molten komatiite from Belingwe also increased up to 12 GPa, however between 12 and 14 GPa the viscosity is nearly constant. In previous studies of depolymerized silicate liquids, the pressure dependence of viscosity has been shown to reverse from positive to negative between 8 and 10 GPa with corresponding changes in activation volume [1] [2]. In contrast, the activation volume for Belingwe liquid decreases to near zero, but does not become negative above 11 GPa. Similarly, the activation volume for Gorgona Island komatiite remains positive throughout the pressure range investigated. Molecular dynamics simulations of simple MgO-SiO2 liquids with NBO/T > 2 also show a positive pressure dependence, reflecting the dominant control of free-volume reduction on the viscosity of depolymerized melts. However, the more rapid reduction in activation volume with pressure in komatiite liquids may be related to the presence of Al, Ti and other cations that interact and undergo coordination changes unavailable in simple silicate liquids. Along Hadean and post-Hadean mantle adiabats the net effect of

  9. The role of spurious correlation in the development of a komatiite alteration model

    Science.gov (United States)

    Butler, John C.

    1986-11-01

    Procedures for detecting alterations in komatiites are described. The research of Pearson (1897) on spurious correlation and of Chayes (1949, 1971) on ratio correlation is reviewed. The equations for the ratio correlation procedure are provided. The ratio correlation procedure is applied to the komatiites from Gorgona Island and the Barberton suite. Plots of the molecular proportion ratios of (FeO + MgO)/TiO2 versus SiO2/TiO2, and correlation coefficients for the komatiites are presented and analyzed.

  10. The Caribbean-Colombian cretaceous igneous province: The internal anatomy of an oceanic plateau

    Science.gov (United States)

    Kerr, Andrew C.; Tarney, John; Marriner, Giselle F.; Nivia, Alvaro; Saunders, Andrew D.

    The Late Cretaceous Caribbean—Colombian igneous province is one of the world's best-exposed examples of a plume-derived oceanic plateau. The buoyancy of the plateau (resulting from residual heat and thick crust) kept it from being totally subducted as it moved eastward with the Farallon Plate from its site of generation in the eastern Pacific and encountered a destructive plate margin. In effect, the plateau makes up much of the Caribbean Plate; it is well exposed around its margins, but more so in accreted terranes in western Colombia (including the well-known Gorgona komatiites and Bolívar mafic/ultramafic cumulates). Compositionally, the lavas of the plateau form three groups: (a) basalts, picrites, and komatiites with light-rare-earth-element (LREE)-depleted chondrite-normalised patterns; (b) basalts with LREE-enriched patterns; and (c) basalts with essentially flat REE patterns (the most dominant type) similar to many of the basalts from the Ontong Java Plateau. These three types demonstrate the heterogeneous nature of the mantle plume source region. The picrites and the komatiites seem to lie nearer the base of the plateau than the more homogeneous basalts; thus, the more MgO-rich melts may have been erupted before large magma chambers had a chance to develop. A reconstructed crustal cross section through the plateau consists of dunitic and pyroxenitic cumulates near the base which are overlain by layered olivine-rich gabbros and more isotropic gabbros. The lowermost eruptive sequence comprises compositionally heterogeneous picrites/komatiites overlain by more homogeneous pillow basalts. Spectacular hornblende-plagioclase veins cut the Bolívar assemblage and these may represent local partial melts of the plateau's base as it was thrusted onto the continent. Subduction-related batholiths and extrusive rocks found around the margin of the province are of two distinct ages; one suite represents pre-plateau collision-related volcanism whereas the other suite

  11. Géochimie isotopique (Nd, Sr) et géochilnie des éléments traces des basaltes alcalins du Massif Central français : Contraintes pétrogénétiques et arguments en faveur du métasomatisme mantellique.

    OpenAIRE

    Chauvel , Catherine

    1982-01-01

    no abstract; Les roches basiques ( basaltes, kimberlites, komatiites, etc ) proviennent par fusion partielle du manteau terrestre. L'étude géochimique de ces roches peut donc nous aider à comprendre la composition chimique et la structure de leurs sources mantelliques. Malgré les variations de composition chimique, les basaltes terrestres modernes peuvent être grossièrement classés en deux familles. La première, la famille des tholéiites, regroupe les basaltes de rides et de planchers océaniq...

  12. Osmium Isotope Compositions of Komatiite Sources Through Time

    Science.gov (United States)

    Walker, R. J.

    2001-12-01

    Extending Os isotopic measurements to ancient plume sources may help to constrain how and when the well-documented isotopic heterogeneities in modern systems were created. Komatiites and picrites associated with plume-related volcanism are valuable tracers of the Os isotopic composition of plumes because of their typically high Os concentrations and relatively low Re/Os. Re-Os data are now available for a variety of Phanerozoic, Proterozoic and Archean komatiites and picrites. As with modern plumes, the sources of Archean and Proterozoic komatiites exhibit a large range of initial 187Os/188Os ratios. Most komatiites are dominated by sources with chondritic Os isotopic compositions (e.g. Song La; Norseman-Wiluna; Pyke Hill; Alexo), though some (e.g. Gorgona) derive from heterogeneous sources. Of note, however, two ca. 2.7 Ga systems, Kostomuksha (Russia) and Belingwe (Zimbabwe), have initial ratios enriched by 2-3% relative to the contemporary convecting upper mantle. These results suggest that if the 187Os enrichment was due to the incorporation of minor amounts of recycled crust into the mantle source of the rocks, the crust formed very early in Earth history. Thus, the Os results could reflect derivation of melt from hybrid mantle whose composition was modified by the addition of mafic crustal material that would most likely have formed between 4.2 and 4.5 Ga. Alternately, the mantle sources of these komatiites may have derived a portion of their Os from the putative 187Os - and 186Os -enriched outer core. For this hypothesis to be applicable to Archean rocks, an inner core of sufficient mass would have to have crystallized sufficiently early in Earth history to generate an outer core with 187Os enriched by at least 3% relative to the chondritic average. Using the Pt-Re-Os partition coefficients espoused by our earlier work, and assuming linear growth of the inner core started at 4.5 Ga and continued to present, would yield an outer core at 2.7 Ga with a gamma Os

  13. Distribution and stratigraphy of basaltic units in Maria Tranquillitatis and Fecunditatis: A Clementine perspective

    Science.gov (United States)

    Rajmon, D.; Spudis, P.

    2004-01-01

    Maria Tranquillitatis and Fecunditatis have been mapped based on Clementine image mosaics and derived iron and titanium maps. Impact craters served as stratigraphic probes enabling better delineation of compositionally different basaltic units, determining the distribution of subsurface basalts, and providing estimates of total basalt thickness and the thickness of the surface units. Collected data indicate that volcanism in these maria started with the eruption of low-Ti basalts and evolved toward medium- and high-Ti basalts. Some of the high-Ti basalts in Mare Tranquillitatis began erupting early and were contemporaneous with the low- and medium-Ti basalts; these units form the oldest units exposed on the mare surface. Mare Tranquillitatis is mostly covered with high- Ti basalts. In Mare Fecunditatis, the volume of erupting basalts clearly decreased as the Ti content increased, and the high-Ti basalts occur as a few patches on the mare surface. The basalt in both maria is on the order of several hundred meters thick and locally may be as thick as 1600 m. The new basalt thickness estimates generally fall within the range set by earlier studies, although locally differ. The medium- to high-Ti basalts exposed at the surfaces of both maria are meters to tens of meters thick.

  14. Complex layering of the Orange Mountain Basalt: New Jersey, USA

    Science.gov (United States)

    Puffer, John H.; Block, Karin A.; Steiner, Jeffrey C.; Laskowich, Chris

    2018-06-01

    The Orange Mountain Basalt of New Jersey is a Mesozoic formation consisting of three units: a single lower inflated sheet lobe about 70 m thick (OMB1), a middle pillow basalt about 10 to 20 m thick (OMB2), and an upper compound pahoehoe flow about 20 to 40 m thick (OMB3). The Orange Mountain Basalt is part of the Central Atlantic Magmatic Province. Quarry and road-cut exposures of OMB1 near Paterson, New Jersey, display some unusual layering that is the focus of this study. OMB1 exposures displays the typical upper crust, core, and basal crust layers of sheet lobes but throughout the Patterson area also display distinct light gray layers of microvesicular basalt mineralized with albite directly over the basal crust and under the upper crust. The lower microvesicular layer is associated with mega-vesicular diapirs. We propose that the upper and lower microvesicular layers were composed of viscous crust that was suddenly quenched before it could devolatilize immediately before the solidification of the core. During initial cooling, the bottom of the basal layer was mineralized with high concentrations of calcite and albite during a high-temperature hydrothermal event. Subsequent albitization, as well as zeolite, prehnite, and calcite precipitation events, occurred during burial and circulation of basin brine heated by recurring Palisades magmatism below the Orange Mountain Basalt. Some of the events experienced by the Orange Mountain Basalt are unusual and place constraints on the fluid dynamics of thick flood basalt flows in general. The late penetration of vesicular diapirs through the entire thickness of the flow interior constrains its viscosity and solidification history.

  15. 182W and HSE constraints from 2.7 Ga komatiites on the heterogeneous nature of the Archean mantle

    Science.gov (United States)

    Puchtel, Igor S.; Blichert-Toft, Janne; Touboul, Mathieu; Walker, Richard J.

    2018-05-01

    While the isotopically heterogeneous nature of the terrestrial mantle has long been established, the origin, scale, and longevity of the heterogeneities for different elements and isotopic systems are still debated. Here, we report Nd, Hf, W, and Os isotopic and highly siderophile element (HSE) abundance data for the Boston Creek komatiitic basalt lava flow (BCF) in the 2.7 Ga Abitibi greenstone belt, Canada. This lava flow is characterized by strong depletions in Al and heavy rare earth elements (REE), enrichments in light REE, and initial ε143Nd = +2.5 ± 0.2 and intial ε176Hf = +4.2 ± 0.9 indicative of derivation from a deep mantle source with time-integrated suprachondritic Sm/Nd and Lu/Hf ratios. The data plot on the terrestrial Nd-Hf array suggesting minimal involvement of early magma ocean processes in the fractionation of lithophile trace elements in the mantle source. This conclusion is supported by a mean μ142Nd = -3.8 ± 2.8 that is unresolvable from terrestrial standards. By contrast, the BCF exhibits a positive 182W anomaly (μ182W = +11.7 ± 4.5), yet is characterized by chondritic initial γ187Os = +0.1 ± 0.3 and low inferred source HSE abundances (35 ± 5% of those estimated for the present-day Bulk Silicate Earth, BSE). Collectively, these characteristics are unique among Archean komatiite systems studied so far. The deficit in the HSE, coupled with the chondritic Os isotopic composition, but a positive 182W anomaly, are best explained by derivation of the parental BCF magma from a mantle domain characterized by a predominance of HSE-deficient, differentiated late accreted material. According to the model presented here, the mantle domain that gave rise to the BCF received only ∼35% of the present-day HSE complement in the BSE before becoming isolated from the rest of the convecting mantle until the time of komatiite emplacement at 2.72 Ga. These new data provide strong evidence for a highly heterogeneous Archean mantle in terms of absolute

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

    Directory of Open Access Journals (Sweden)

    R.J. Sweeney

    1986-11-01

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

  17. Introduction to nickel sulfide orebodies and komatiites of the Black Swan area, Yilgarn Craton, Western Australia

    Science.gov (United States)

    Barnes, S. J.

    2004-11-01

    The Black Swan district, 70 km north east of Kalgoorlie in the Archaean Yilgarn Craton of Western Australia, hosts massive and disseminated nickel sulfide orebodies associated with komatiites. The host rocks and ores preserve some remarkable primary igneous features, which provide important clues as to the origin of komatiite-hosted nickel ores. The series of papers that follow report an extremely detailed study of the petrology, volcanology and geochemistry of these unusually well-preserved orebodies and their host rocks.

  18. Re - Os isotopic constraints on the origin of volcanic rocks, Gorgona Island, Colombia: Os isotopic evidence for ancient heterogeneities in the mantle

    Science.gov (United States)

    Walker, R.J.; Echeverria, L.M.; Shirey, S.B.; Horan, M.F.

    1991-01-01

    The Re - Os isotopic systematics of komatiites and spatially associated basalts from Gorgona Island, Colombia, indicate that they were produced at 155??43 Ma. Subsequent episodes of volcanism produced basalts at 88.1??3.8 Ma and picritic and basaltic lavas at ca. 58 Ma. The age for the ultramafic rocks is important because it coincides with the late-Jurassic, early-Cretaceous disassembly of Pangea, when the North- and South-American plates began to pull apart. Deep-seated mantle upwelling possibly precipitated the break-up of these continental plates and caused a tear in the subducting slab west of Gorgona, providing a rare, late-Phanerozoic conduit for the komatiitic melts. Mantle sources for the komatiites were heterogeneous with respect to Os and Pb isotopic compositions, but had homogeneous Nd isotopic compositions (??Nd+9??1). Initial 187Os/186Os normalized to carbonaceous chondrites at 155 Ma (??Os) ranged from 0 to +22, and model-initial ?? values ranged from 8.17 to 8.39. The excess radiogenic Os, compared with an assumed bulk-mantle evolution similar to carbonaceous chondrites, was likely produced in portions of the mantle with long-term elevated Re concentrations. The Os, Pb and Nd isotopic compositions, together with major-element constraints, suggest that the sources of the komatiites were enriched more than 1 Ga ago by low (<20%) and variable amounts of a basalt or komatiite component. This component was added as either subducted oceanic crust or melt derived from greater depths in the mantle. These results suggest that the Re - Os isotope system may be a highly sensitive indicator of the presence of ancient subducted oceanic crust in mantle-source regions. ?? 1991 Springer-Verlag.

  19. Petrogenesis of 3.15 Ga old Banasandra komatiites from the Dharwar craton, India: Implications for early mantle heterogeneity

    Directory of Open Access Journals (Sweden)

    J.M. Maya

    2017-05-01

    Full Text Available Spinifex-textured, magnesian (MgO >25 wt.% komatiites from Mesoarchean Banasandra greenstone belt of the Sargur Group in the Dharwar craton, India were analysed for major and trace elements and 147,146Sm-143,142Nd systematics to constrain age, petrogenesis and to understand the evolution of Archean mantle. Major and trace element ratios such as CaO/Al2O3, Al2O3/TiO2, Gd/Yb, La/Nb and Nb/Y suggest aluminium undepleted to enriched compositional range for these komatiites. The depth of melting is estimated to be varying from 120 to 240 km and trace-element modelling indicates that the mantle source would have undergone multiple episodes of melting prior to the generation of magmas parental to these komatiites. Ten samples of these komatiites together with the published results of four samples from the same belt yield 147Sm-143Nd isochron age of ca. 3.14 Ga with an initial ɛNd(t value of +3.5. High precision measurements of 142Nd/144Nd ratios were carried out for six komatiite samples along with standards AMES and La Jolla. All results are within uncertainties of the terrestrial samples. The absence of 142Nd/144Nd anomaly indicates that the source of these komatiites formed after the extinction of 146Sm, i.e. 4.3 Ga ago. In order to evolve to the high ɛNd(t value of +3.5 by 3.14 Ga the time-integrated ratio of 147Sm/144Nd should be 0.2178 at the minimum. This is higher than the ratios estimated, so far, for mantle during that time. These results indicate at least two events of mantle differentiation starting with the chondritic composition of the mantle. The first event occurred very early at ∼4.53 Ga to create a global early depleted reservoir with superchondritic Sm/Nd ratio. The source of Isua greenstone rocks with positive 142Nd anomaly was depleted during a second differentiation within the life time of 146Sm, i.e. prior to 4.46 Ga. The source mantle of the Banasandra komatiite was a result of a differentiation event that occurred

  20. Rheological Studies of Komatiite Liquids by In-Situ Falling Sphere Viscometry

    Science.gov (United States)

    O Dwyer, L.; Lesher, C. E.; Baxter, G.; Clark, A.; Fuss, T.; Tangeman, J.; Wang, Y.

    2005-12-01

    The rheological properties of komatiite liquids at high pressures and temperatures are being investigated by the in situ falling sphere technique, using the T-25 multianvil apparatus at the GSECARS 13 ID-D-D beamline at the Advanced Photon Source, ANL. The refractory and fluid nature of komatiite and other ultramafic liquids relevant to the Earth's deep interior, presents unique challenges for this approach. To reduce the density contrast between the melt and the marker sphere, and thus increase the Stoke's travel time, we have begun testing various composite spheres composed of refractory silicates and metals. Two successful custom designs are zirconia silicate mantled by Pt and Pt mantled by forsterite. These custom spheres contain sufficient Pt to absorb x-rays, while containing sufficient low-density refractory silicate so that marker sphere densities are in the range of 4-6 g/cc. These relatively more buoyant spheres increase travel time. These custom spheres, together with Re or Pt marker spheres, have been used to determine the viscosity of Gorgona anhydrous komatiite around 1600 ° C between 3.5 and 6 GPa. Initial experiments yield viscosities of 2.8 Pa s at 3.5 GPa, 5.3 Pa s at 4.6 GPa and 7.6 Pa s at 6 GPa. The observed positive pressure dependence of viscosity is consistent with recent results on pyrolite composition liquids and suggests that the activation volume for highly depolymerized melts will be positive for at least upper mantle conditions. The development of low-density, x-ray detectable marker spheres has applications in studies of melt density, whereby in situ detection of sink-float behavior during heating and compression cycles may be possible.

  1. Re — Os isotopic constraints on the origin of volcanic rocks, Gorgona Island, Colombia: Os isotopic evidence for ancient heterogeneities in the mantle

    Science.gov (United States)

    Walker, R. J.; Echeverria, L. M.; Shirey, S. B.; Horan, M. F.

    1991-04-01

    The Re — Os isotopic systematics of komatiites and spatially associated basalts from Gorgona Island, Colombia, indicate that they were produced at 155±43 Ma. Subsequent episodes of volcanism produced basalts at 88.1±3.8 Ma and picritic and basaltic lavas at ca. 58 Ma. The age for the ultramafic rocks is important because it coincides with the late-Jurassic, early-Cretaceous disassembly of Pangea, when the North- and South-American plates began to pull apart. Deep-seated mantle upwelling possibly precipitated the break-up of these continental plates and caused a tear in the subducting slab west of Gorgona, providing a rare, late-Phanerozoic conduit for the komatiitic melts. Mantle sources for the komatiites were heterogeneous with respect to Os and Pb isotopic compositions, but had homogeneous Nd isotopic compositions (ɛNd+9±1). Initial 187Os/186Os normalized to carbonaceous chondrites at 155 Ma (γOs) ranged from 0 to +22, and model-initial μ values ranged from 8.17 to 8.39. The excess radiogenic Os, compared with an assumed bulk-mantle evolution similar to carbonaceous chondrites, was likely produced in portions of the mantle with long-term elevated Re concentrations. The Os, Pb and Nd isotopic compositions, together with major-element constraints, suggest that the sources of the komatiites were enriched more than 1 Ga ago by low (<20%) and variable amounts of a basalt or komatiite component. This component was added as either subducted oceanic crust or melt derived from greater depths in the mantle. These results suggest that the Re — Os isotope system may be a highly sensitive indicator of the presence of ancient subducted oceanic crust in mantle-source regions.

  2. Magma source evolution beneath the Caribbean oceanic plateau: New insights from elemental and Sr-Nd-Pb-Hf isotopic studies of ODP Leg 165, Site 1001 basalts

    Science.gov (United States)

    Kerr, A. C.; Pearson, G.; Nowell, G.

    2008-12-01

    Ocean Drilling Project Leg 165 sampled 38m of the basaltic basement of the Caribbean plate at Site 1001 on the Hess Escarpment. The recovered section consists of 12 basaltic flow units which yield a weighted mean Ar-Ar age of 80.9±0.9 Ma (Sinton et al., 2000). The basalts (6.4-8.5 wt.% MgO) are remarkably homogeneous in composition and are more depleted in incompatible trace elements than N-MORB. Markedly, depleted initial radiogenic isotope ratios reveal a long-term history of depletion. Although the Site 1001 basalts are superficially similar to N-MORB, radiogenic isotopes in conjunction with incompatible trace element ratios show that the basalts have more similarity to the depleted basalts and komatiites of Gorgona Island. This chemical composition strongly implies that the Site 1001 basalts are derived from a depleted mantle plume component and not from depleted ambient upper mantle. Therefore the Site 1001 basalts are, both compositionally and tectonically, a constituent part of the Caribbean oceanic plateau. Mantle melt modelling suggests that the Site 1001 lavas have a composition which is consistent with second-stage melting of compositionally heterogeneous mantle plume source material which had already been melted, most likely to form the 90Ma basalts of the plateau. The prolonged residence (>10m.y.) of residual mantle plume source material below the region, confirms computational model predictions and places significant constraints on tectonic models of Caribbean evolution in the late Cretaceous, and the consequent environmental impact of oceanic plateau volcanism. Reference Sinton, C.W., et al., 2000. Geochronology and petrology of the igneous basement at the lower Nicaraguan Rise, Site 1001. Proceedings of the Ocean Drilling Program, Scientific Results. Leg 165. pp. 233-236.

  3. Descriptive summary of the Grande Ronde Basalt type section, Columbia River Basalt Group

    International Nuclear Information System (INIS)

    Camp, V.E.; Price, S.M.; Reidel, S.P.

    1978-10-01

    The Grande Ronde Basalt type section, located in extreme southeastern Washington, was measured, sampled, and characterized. The section is 800 meters thick and is comprised of 35 Grande Ronde Basalt flows. These flows are divisible into 3 magnetostratiographic units termed, in ascending order, the R 1 , the N 1 , and the R 2 . The R 1 unit is represented by 13 reversely polarized flows; the N 1 unit, by 13 normally polarized flows; and the R 2 , by 9 reversely polarized flows. Chemically, the Grande Ronde Basalt flows are divided into 2 major groups, termed A and B. The compositions of the lower 9 flows, members of Group A, are similar to either the high-Mg Grande Ronde chemical type, the high-Ti Grande Ronde chemical type, or the Pomona chemical type. The compositions of the upper 25 flows, members of Group B, are predominantly similar to the low-Mg Grande Ronde chemical type. Petrographically, the Grande Ronde Basalt flows are generally fine grained and aphyric, and have a intergranular or intersertal micro-texture. Major mineral phases include plagioclase (An/sub 40-60/) and augite; minor mineral phases include pigeonite, orthopyroxene, ilmenite, titanomagnetite, and olivine. Group A flows generally contain more olivine and less pigeonite than do Group B flows. 6 figures, 6 tables

  4. Komatiites of the Onverwacht Group, S. Africa: REE geochemistry, Sm/Nd age and mantle evolution

    Science.gov (United States)

    Jahn, Bor-Ming; Gruau, G.; Glikson, A. Y.

    1982-08-01

    Komatiites of the Tjakastad Subgroup of the Onverwacht Group (S. Africa) were dated by the Sm/Nd method. A whole-rock isochron yields an age of 3.56±0.24 (2 σ) AE, with initial 143Nd/144Nd ratio of 0.50818±23 (2 σ), corresponding to ɛ Nd( T)= + 1.9±4.5. This age is interpreted as the time of initial Onverwacht volcanism. This result agrees with earlier Sm/Nd data of Hamilton et al. (1979) and is consistent with the Rb-Sr result of Jahn and Shih (1974). Komatiites may be divided into 3 groups based on the typology of heavy REE distributions (Jahn and Gruau 1981). According to this scheme, the Onverwacht komatiites of the present study belong to two groups: the predominant Group II rocks showing (Gd/Yb)N≃1.4, CaO/Al2O3 = 1.33, Al2O3/TiO2≃10.6; and the subordinate Group III rocks with (Gd/Yb)Nconnotation of the chemical parameters, such as CaO/Al2O3, (Gd/Yb)N or Al2O3/TiO2 ratio has not been firmly established. The characteristic “high” CaO/Al2O3 or (Gd/Yb)N ratios in many Onverwacht Group rocks can also be explained as a result of local short-term mantle heterogeneity.

  5. New Ages for Gorgona Island, Colombia: Implications for Previous Petrogenetic and Tectonic Models

    Science.gov (United States)

    Serrano Duran, L.; Lopez Martinez, M.; Ferrari, L.

    2007-05-01

    The Gorgona Island, located 50 km to the west of the Colombian Pacific coast, is the only known site with Phanerozoic komatiites in the world besides a key element in several reconstruction of the interaction between the Caribbean and the South America Plate. The Gorgona komatiites are part of an igneous complex that also includes picritic basalts and breccias, gabbros and peridotites (dunites and wherlites), and is covered by deformed mid-Eocene and younger underformed marine sediments. Datings of the igneous rocks were only performed on basalts and include an 86 Ma K-Ar age, an 88.9 ± 1.2 Ma weighted mean of four Ar-Ar ages and an 89.2 ± 5.2 Ma Re-Os isochron age from basalts. Gorgona rocks are affected by reverse faulting with a general eastward vergence. The island is the only subaerially exposed part of a NE elongated sliver accreted in a dextral transpressional regime to the South America continental margin between the Late Eocene and the Early Miocene. Petrologic studies found large spread in radiogenic isotopes and incompatible trace element ratios in Gorgona ultramafic rocks, which have been interpreted as requiring at least two different sources of: 1) a depleted mantle responsible for the generation of the komatiites and most basalts, and 2) an enriched mantle responsible for some rarer enriched basalts and picrites. Despite the large compositional and isotopic heterogeneity the most common interpretation is that the Gorgona ultramafic rocks are the product of a single mantle plume, although it has recently proposed that this would be a separate plume from that generating the bulk of the Caribbean plateau at ~90 Ma. Our new study focused on the geochronology of the Gorgona igneous suite as we consider that this tectonically and petrologically complex island is unlike to have such a narrow age range. We attempted to date eight samples of komatiites, basalts and gabbros by Ar-Ar laser step heating. For four of these samples we successfully obtain

  6. Geophysical logging and hydrologic testing of deep basalt flows in the Rattlesnake Hills Well Number One

    International Nuclear Information System (INIS)

    Gephart, R.E.; Eddy, P.A.; Deju, R.A.

    1979-01-01

    Geophysical logging and hydrologic testing were conducted in the Rattlesnake Hills Well Number One located along the western boundary of the Hanford Site in south-central Washington. Three-dimensional velocity, Seisviewer and caliper logging were completed across 2,000 feet of basalt rock within the Wanapum and Grande Ronde formations. Drillstem testing focused along a 250-foot interval of the Grande Ronde Formation. Individual high- (approx. 2.7-2.9 grams per cubic centimeter) and low-density (approx. 2.3-2.6 grams per cubic centimeter) basalt zones within the Wanapum Formation are generally less than 50 feet thick. Within the estimated thickness of the Grande Ronde Formation, 85 percent of the low-density zones are less than 50 feet thick, compared to 55 percent of those of higher density. The Grande Ronde Formation has 13 high-density zones varying in thickness from 51 to 230 feet. Logging data suggest the thicknesses of low-density are independent of the thicknesses of the associated and underlying higher density columnar basalts. Eleven drillstem tests were conducted across selected intervals within the Grande Ronde Formation. Hydraulic conductivity values calculated for the low-density basalt zones ranged between 1.7 x 10 -7 and 3.8 x 10 -9 centimeters per second; those for high-density zones were between 1.1 x 10 -8 and 4.7 x 10 -9 centimeters per second

  7. Melt inclusion evidence for a volatile-enriched (H2O, Cl, B) component in parental magmas of Gorgona Island komatiites

    Science.gov (United States)

    Kamenetsky, V.; Sobolev, A.; McDonough, W.

    2003-04-01

    Late Cretaceous komatiites of Gorgona Island are unambiguous samples of ultra-mafic melts related to a hot and possibly 'wet' mantle plume. Despite significant efforts in studying komatiites, their volatile abundances remain largely unknown because of significant alteration of rocks and lack of fresh glasses. This work presents major, trace and volatile element data for 22 partially homogenised (at 1275oC and 1 bar pressure) melt inclusions in olivine (Fo 90.5-91.5) from a Gorgona Isl. komatiite (# Gor 94-3). Major element compositions (except FeO which is notably lower by up to 5 wt% as a result of post-entrapment re-equilibration) and most lithophile trace elements of melt inclusions are indistinguishable from the whole rock komatiites. With the exception of three inclusions that have low Na, H2O, Cl, F and S (likely compromised and degassed during heating) most compositions are characterised by relatively constant and high volatile abundances (H2O 0.4-0.8 wt%, Cl 0.02-0.03 wt%, B 0.8-1.4 ppm). These are interpreted as representative of original volatiles in parental melts because they correspond to the internal volatile pressure in the closed inclusions significantly exceeding 1 bar pressure of heating experiment. Although H2O is strongly enriched (PM-normalised H2O/Ce 10-17) its concentrations correlate well with many elements (e.g. Yb, Er, Y, Ti, Sr, Be). Other positive anomalies on the overall depleted (La/Sm 0.26-0.33) PM normalized compositional spectra of melt inclusions are shown by B (B/K 2.4-5.4) and Cl (Cl/K 11-16). Compositions of melt inclusions, when corrected for Fe loss and recalculated in equilibrium with host olivine, have high MgO (15.4-16.4 wt%; Mg# of 74) and substantial H2O (0.4-0.6 wt%) contents. This together with the data on other 'enriched' elements argues for the presence of previously unknown volatile-enriched component in the parental melts of Gorgona Isl. komatiites. We discuss contamination of magmas by altered oceanic crust in the

  8. Implications of Nb/U, Th/U and Sm/Nd in plume magmas for the relationship between continental and oceanic crust formation and the development of the depleted mantle

    Science.gov (United States)

    Campbell, Ian H.

    2002-05-01

    The Nb/U and Th/U of the primitive mantle are 34 and 4.04 respectively, which compare with 9.7 and 3.96 for the continental crust. Extraction of continental crust from the mantle therefore has a profound influence on its Nb/U but little influence on its Th/U. Conversely, extraction of midocean ridge-type basalts lowers the Th/U of the mantle residue but has little influence on its Nb/U. As a consequence, variations in Th/U and Nb/U with Sm/Nd can be used to evaluate the relative importance of continental and basaltic crust extraction in the formation of the depleted (Sm/Nd enriched) mantle reservoir. This study evaluates Nb/U, Th/U, and Sm/Nd variations in suites of komatiites, picrites, and their associated basalts, of various ages, to determine whether basalt and/or continental crust have been extracted from their source region. Emphasis is placed on komatiites and picrites because they formed at high degrees of partial melting and are expected to have Nb/U, Th/U, and Sm/Nd that are essentially the same as the mantle that melted to produce them. The results show that all of the studied suites, with the exception of the Barberton, have had both continental crust and basaltic crust extracted from their mantle source region. The high Sm/Nd of the Gorgona and Munro komatiites require the elevated ratios seen in these suites to be due primarily to extraction of basaltic crust from their source regions, whereas basaltic and continental crust extraction are of subequal importance in the source regions of the Yilgarn and Belingwe komatiites. The Sm/Nd of modern midocean ridge basalts lies above the crustal extraction curve on a plot of Sm/Nd against Nb/U, which requires the upper mantle to have had both basaltic and continental crust extracted from it. It is suggested that the extraction of the basaltic reservoir from the mantle occurs at midocean ridges and that the basaltic crust, together with its complementary depleted mantle residue, is subducted to the core

  9. High Ni in Archean tholeiites

    Science.gov (United States)

    Arndt, Nicholas T.

    1991-03-01

    Archean tholeiites generally have higher Ni, Co. Cr and Fe than most younger tholeiites with similar MgO contents. These characteristics cannot be attributed to high T or P batch melting in the Archean mantle, because, although such melts are enriched in siderophile elements, they have higher MgO than normal tholeiites. As primary melts fractionate to lower MgO, they lose Ni, Co and Cr. Nor can the differences between Archean and younger tholeiites be attributed to secular variation in mantle compositions because Archean komatiites have Ni, Co, Cr contents similar to modern (Gorgona) komatiites. It is suggested that the high siderophile element content of Archean tholeiites results from mixing of either komatiitic with basaltic magmas, as might occur in an ascending, melting mantle plume or column, or of komatiite and more evolved rocks, as may take place when komatiite encounters and assimilates crustal rocks.

  10. Archean komatiite volcanism controlled by the evolution of early continents.

    Science.gov (United States)

    Mole, David R; Fiorentini, Marco L; Thebaud, Nicolas; Cassidy, Kevin F; McCuaig, T Campbell; Kirkland, Christopher L; Romano, Sandra S; Doublier, Michael P; Belousova, Elena A; Barnes, Stephen J; Miller, John

    2014-07-15

    The generation and evolution of Earth's continental crust has played a fundamental role in the development of the planet. Its formation modified the composition of the mantle, contributed to the establishment of the atmosphere, and led to the creation of ecological niches important for early life. Here we show that in the Archean, the formation and stabilization of continents also controlled the location, geochemistry, and volcanology of the hottest preserved lavas on Earth: komatiites. These magmas typically represent 50-30% partial melting of the mantle and subsequently record important information on the thermal and chemical evolution of the Archean-Proterozoic Earth. As a result, it is vital to constrain and understand the processes that govern their localization and emplacement. Here, we combined Lu-Hf isotopes and U-Pb geochronology to map the four-dimensional evolution of the Yilgarn Craton, Western Australia, and reveal the progressive development of an Archean microcontinent. Our results show that in the early Earth, relatively small crustal blocks, analogous to modern microplates, progressively amalgamated to form larger continental masses, and eventually the first cratons. This cratonization process drove the hottest and most voluminous komatiite eruptions to the edge of established continental blocks. The dynamic evolution of the early continents thus directly influenced the addition of deep mantle material to the Archean crust, oceans, and atmosphere, while also providing a fundamental control on the distribution of major magmatic ore deposits.

  11. Pb isotopes of Gorgona Island (Colombia): Isotopic variations correlated with magma type

    Energy Technology Data Exchange (ETDEWEB)

    Dupre, B.; Echeverria, L.M. (Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut), Mainz (Germany, F.R.))

    1984-02-01

    Lead isotopic results obtained on komatiites and basalts from Gorgona Island provide evidence of large isotopic variations within a restricted area (8x2.5 km). The variations are correlated with differences in volcanic rock type. The highest isotopic ratios (/sup 206/Pb//sup 204/Pb proportional 19.75) correspond to tholeiites which make up most of the island. The lowest ratios (18.3) correspond to the komatiites of the west coast of the island.

  12. Extreme Hf and light Fe isotopes in Archean komatiites - a remnant of very early mantle depletion?

    Science.gov (United States)

    Nebel, O.; Sossi, P.; Campbell, I. H.; Van Kranendonk, M. J.

    2014-12-01

    Hafnium isotope signatures in some Archean komatiites (ca. 3.5-3.0 billion years old) require a mantle source with a time-integrated Lu/Hf that exceeds average modern depleted mantle. Investigation of the timing and locus of parent-daughter fractionation in their mantle sources potentially constrains differentiation processes in the early Earth and their subsequent distribution and storage. In addition, they may help to constrain the Hf isotope evolution of the greater depleted mantle. In order to shed light on these processes, we discuss radiogenic Hf isotopes in conjunction with stable Fe isotope systematics in Archean komatiites from the Pilbara craton in Western Australia. Our findings indicate that, after careful evaluation of the effects of alteration, pristine samples are characterised by initial 176Hf/177Hf, which lie above the age-corrected depleted mantle, as a consequence of ancient melt extraction. Iron isotope systematics for these samples further point to a mantle source that is isotopically lighter than average modern depleted mantle, which is also consistent with melt-depletion. Taken together, these observations require a component of an old, super-depleted reservoir in the komatiite mantle source(s) that survived in the mantle for possibly hundreds of millions of years. The Lu/Hf of this refractory mantle appears to be complementary to, and therefore contemporaneous with, the first terrestrial crust, as preserved in Hadean (i.e., > 4 Ga) detrital zircon cores, which may indicate a causal relationship between them. We will discuss implications for very early mantle dynamics and the formation of very early mantle reservoirs.

  13. The Archean komatiite-hosted, PGE-bearing Ni-Cu sulfide deposit at Vaara, eastern Finland: evidence for assimilation of external sulfur and post-depositional desulfurization

    Science.gov (United States)

    Konnunaho, J. P.; Hanski, E. J.; Bekker, A.; Halkoaho, T. A. A.; Hiebert, R. S.; Wing, B. A.

    2013-12-01

    Archean komatiites host important resources of Ni, Cu, Co, and PGE, particularly in Western Australia and Canada. In Finland, several small, low-grade sulfide deposits have been found in komatiites, including the ca. 2.8 Ga Vaara deposit in the Archean Suomussalmi greenstone belt. It occurs in the central part of the serpentinized olivine cumulate zone of a komatiitic extrusive body and is composed of disseminated interstitial sulfides consisting of pyrite, pentlandite, millerite, violarite, and chalcopyrite accompanied by abundant magnetite. Although currently subeconomic, the mineralization is interesting due to the very high chalcophile element contents of the sulfide fraction (38 wt% Ni, 3.4 wt% Cu, 0.7 wt% Co, 22.4 ppm Pd, and 9.5 ppm Pt). The sulfides occur in relatively Cr-poor olivine cumulates suggesting involvement of a chromite-undersaturated magma. The parental magma was an Al-undepleted komatiite with an estimated MgO content of at least 24 wt%. In contrast to the common komatiite types in the eastern Finland greenstone belts, the Vaara rocks are moderately enriched in LREE relative to MREE, suggesting that crustal contamination played an important role in the genesis of the Vaara deposit. Multiple sulfur isotope data reveal considerable mass-independent sulfur isotope fractionation both in country rock sedimentary sulfides (Δ33S ranges from -0.50 to +2.37 ‰) and in the Vaara mineralization (Δ33S ranges from +0.53 to +0.66 ‰), which provides strong evidence for incorporation of crustal sulfur. Extensive replacement of interstitial sulfides by magnetite and the presence of millerite- and violarite-bearing, pyrrhotite-free sulfide assemblages indicate significant post-magmatic, low-temperature hydrothermal oxidation of the primary magmatic pyrrhotite-pentlandite-chalcopyrite assemblages and associated sulfur loss that led to a significant upgrading of the original metal tenors of the Vaara deposit.

  14. Hydrologic testing methodology and results from deep basalt boreholes

    International Nuclear Information System (INIS)

    Strait, S.R.; Spane, F.A.; Jackson, R.L.; Pidcoe, W.W.

    1982-05-01

    The objective of the hydrologic field-testing program is to provide data for characterization of the groundwater systems wihin the Pasco Basin that are significant to understanding waste isolation. The effort is directed toward characterizing the areal and vertical distributions of hydraulic head, hydraulic properties, and hydrochemistry. Data obtained from these studies provide input for numerical modeling of groundwater flow and solute transport. These models are then used for evaluating potential waste migration as a function of space and time. The groundwater system beneath the Hanford Site and surrounding area consists of a thick, accordantly layered sequence of basalt flows and associated sedimentary interbed that primarily occur in the upper part of the Columbia River basalt. Permeable horizons of the sequence are associated with the interbeds and the interflow zones within the basalt. The columnar interiors of a flow act as low-permeability aquitards, separating the more-permeable interflows or interbeds. This paper discusses the hydrologic field-gathering activities, specifically, field-testing methodology and test results from deep basalt boreholes

  15. 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.

  16. Pb isotopes of Gorgona Island (Colombia): Isotopic variations correlated with magma type

    International Nuclear Information System (INIS)

    Dupre, B.; Echeverria, L.M.

    1984-01-01

    Lead isotopic results obtained on komatiites and basalts from Gorgona Island provide evidence of large isotopic variations within a restricted area (8x2.5 km). The variations are correlated with differences in volcanic rock type. The highest isotopic ratios ( 206 Pb/ 204 Pbproportional19.75) correspond to tholeiites which make up most of the island. The lowest ratios (18.3) correspond to the komatiites of the west coast of the island. Other rock types (komatiites of the east coast, K-tholeiites, picrites and tuffs) have isotopic characteristics intermediate between these two extreme values. These results are explained by the existence of two distinct mantle sourbe regions, and by mixing or contamination between them. (orig.)

  17. Pb isotopes of Gorgona Island (Colombia): isotopic variations correlated with magma type

    Science.gov (United States)

    Dupré, B.; Echeverría, L. M.

    1984-02-01

    Lead isotopic results obtained on komatiites and basalts from Gorgona Island provide evidence of large isotopic variations within a restricted area (8 × 2.5 km). The variations are correlated with differences in volcanic rock type. The highest isotopic ratios ( 206Pb/ 204Pb˜ 19.75 ) correspond to tholeiites which make up most of the island. The lowest ratios (18.3) correspond to the komatiites of the west coast of the island. Other rock types (komatiites of the east coast, K-tholeiites, picrites and tuffs) have isotopic characteristics intermediate between these two extreme values. These results are explained by the existence of two distinct mantle source regions, and by mixing or contamination between them.

  18. Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Busby-Spera, C.J.

    1987-09-01

    Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed and have thick flow units with mega-pillows. Basalts on distal parts of the apron (about 15 to 20 km down paleo-current) are dominated by pillow fragment breccias (flow foot rubble), and individual lava flows are generally thin, with small pillows, suggesting that the distal ends of lava flows, erupted upslope, are represented. These distal flow fronts, however, are interstratified with features that typically form close to a vent, including thick massive to mega-pillowed lavas and lava tubes up to 8 m in diameter. It is inferred that a fissure (or system of fissures) extended from the arc into the backarc basin, erupting basalt lavas onto both proximal and distal parts of the volcaniclastic apron. Such intraplate volcanism may be common on the hot frontal arc side of backarc basins. 26 references.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ward, A.W. Jr.

    1976-11-01

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

  20. 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.

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

    International Nuclear Information System (INIS)

    Zorla, Eyüp; Ipbüker, Cagatay; Biland, Alex; Kiisk, Madis; Kovaljov, Sergei; Tkaczyk, Alan H.; Gulik, Volodymyr

    2017-01-01

    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.

  2. Crustal thickness controlled by plate tectonics

    DEFF Research Database (Denmark)

    Artemieva, Irina M.; Meissner, Rolf

    2012-01-01

    /gabbro–eclogite phase transition in crustal evolution and the links between lithosphere recycling, mafic magmatism, and crustal underplating. We advocate that plate tectonics processes, togetherwith basalt/gabbro–eclogite transition, limit crustal thickness worldwide by providing effective mechanisms of crustal...

  3. The System Forsterite-Diopside-Enstatite up to 70 kbar and its Significance to the Genesis of Komatiites

    Science.gov (United States)

    Dasgupta, S.; Gupta, A. K.

    2011-12-01

    Liquidus phase relations in the system forsterite-diopside-enstatite has been made at 70 kbar under anhydrous conditions using a Walker-type multi-anvil high pressure apparatus. Positions of the pseudoeutectic/ invariant, minimum points and amount of solid solutions of appearing phases are summarized in table 1. Comparison of these phase relations with those conducted by previous investigators at lower pressures and temperatures shows that the fosterite-pyroxene liquidus boundary shifts toward forsterite and away from the diopside apex with increasing pressure. Microprobe analyses indicate that the maximum amount of MgSiO3 that can be incorporated in diopside increases with pressure, and at the solidus (70 kbar, 2010°C), it is about 82%. On the basis of EPMA analyses of coexisting liquid and crystalline phases, three-phase triangles have been constructed. It is observed that at 70 kbar, the early partial melt generated from a model peridotite does not precipitate orthopyroxene. If such a melt instead of crystallizing in-situ, ascend to the surface, then the polybaric-polythermal crystallization path should never intersect the liquidus phase field of orthopyroxene, enstatitess may then appear in the solidus as an exsolution product. Our calculation shows that at 31% partial melting of a model mantle, orthopyroxene should appear as a liquidus phase. With further increase in the degree of partial melting (42-60%), proportion of orthopyroxene crystallizing from the melt progressively increases. With reference to the above discussion we propose that the Gorgona komatiites which are primarily orthopyroxene-deficient komatiites, are an outcome of low degree of partial melting, whereas the orthopyroxene-bearing Commondale komatiites of the southern Kaapvaal Craton, South Africa, are the outcome of a larger degree of partial melting, both generated from melting of an anhydrous mantle.

  4. The fluid dynamics of a basaltic magma chamber replenished by influx of hot, dense ultrabasic magma

    Science.gov (United States)

    Huppert, Herbert E.; Sparks, R. Stephen J.

    1981-09-01

    This paper describes a fluid dynamical investigation of the influx of hot, dense ultrabasic magma into a reservoir containing lighter, fractionated basaltic magma. This situation is compared with that which develops when hot salty water is introduced under cold fresh water. Theoretical and empirical models for salt/water systems are adapted to develop a model for magmatic systems. A feature of the model is that the ultrabasic melt does not immediately mix with the basalt, but spreads out over the floor of the chamber, forming an independent layer. A non-turbulent interface forms between this layer and the overlying magma layer across which heat and mass are transferred by the process of molecular diffusion. Both layers convect vigorously as heat is transferred to the upper layer at a rate which greatly exceeds the heat lost to the surrounding country rock. The convection continues until the two layers have almost the same temperature. The compositions of the layers remain distinct due to the low diffusivity of mass compared to heat. The temperatures of the layers as functions of time and their cooling rate depend on their viscosities, their thermal properties, the density difference between the layers and their thicknesses. For a layer of ultrabasic melt (18% MgO) a few tens of metres thick at the base of a basaltic (10% MgO) magma chamber a few kilometres thick, the temperature of the layers will become nearly identical over a period of between a few months and a few years. During this time the turbulent convective velocities in the ultrabasic layer are far larger than the settling velocity of olivines which crystallise within the layer during cooling. Olivines only settle after the two layers have nearly reached thermal equilibrium. At this stage residual basaltic melt segregates as the olivines sediment in the lower layer. Depending on its density, the released basalt can either mix convectively with the overlying basalt layer, or can continue as a separate

  5. Effect of chromate action on morphology of basalt-inhabiting bacteria

    International Nuclear Information System (INIS)

    Lin Zhang; Zhu Ying; Kalabegishvili, Tamaz L.; Tsibakhashvili, Nelly Y.; Holman, Hoi-Ying

    2006-01-01

    Basalt-inhabiting bacteria isolated from polluted basalts have been demonstrated to be able to tolerate moderate to high concentrations of chromium oxyanions such as chromate. Previous results have shown that macromolecules outside the cell wall of bacteria may play an important role in this survival ability. In this paper, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were applied to study the chromate-induced morphological changes in chromate-resistant basalt-inhabiting Arthrobacter K-2 and K-4, which were isolated from the Republic of Georgia. The surfaces of both strains changed in the presence of chromate. TEM thin sections show that chromate stimulates the appearance of bacteria capsular polysaccharide outside the cell wall, although the chromate concentration does not have a strong effect on the capsular thickness. These results, in conjunction with those reported earlier, provide direct evidence to show that capsular polysaccharides of the bacteria play very important role for the reduction and localization of chromate

  6. Preliminary feasibility study on storage of radioactive wastes in Columbia River basalts. Volume I

    International Nuclear Information System (INIS)

    1976-11-01

    Geologic, hydrologic, heat transfer and rock-waste compatibility studies conducted by the Atlantic Richfield Hanford Company to evaluate the feasibility of storing nuclear wastes in caverns mined out into the Columbia River basalts are discussed. The succession of Columbia River Plateau flood basalts was sampled at various outcrops and in core holes and the samples were analyzed to develop a stratigraphic correlation of the various basalt units and sedimentary interbeds. Hydrologic tests were made in one bore hole to assess the degree of isolation in the various deep aquifers separated by thick basalt accumulations. Earthquake and tectonic studies were conducted to assess the tectonic stability of the Columbia River Plateau. Studies were made to evaluate the extent of heat dissipation from stored radioactive wastes. Geochemical studies were aimed at evaluating the compatibility between the radioactive wastes and the basalt host rocks. Data obtained to-date have allowed development of a hydrostratigraphic framework for the Columbia River Plateau and a preliminary understanding of the deep aquifer systems. Finally, the compilation of this information has served as a basis for planning the studies necessary to define the effectiveness of the Columbia River basalts for permanently isolating nuclear wastes from the biosphere

  7. Experimental research on continuous basalt fiber and basalt-fibers-reinforced polymers

    Science.gov (United States)

    Zhang, Xueyi; Zou, Guangping; Shen, Zhiqiang

    2008-11-01

    The interest for continuous basalt fibers and reinforced polymers has recently grown because of its low price and rich natural resource. Basalt fiber was one type of high performance inorganic fibers which were made from natural basalt by the method of melt extraction. This paper discusses basic mechanical properties of basalt fiber. The other work in this paper was to conduct tensile testing of continuous basalt fiber-reinforced polymer rod. Tensile strength and stress-strain curve were obtained in this testing. The strength of rod was fairly equal to rod of E-glass fibers and weaker than rod of carbon fibers. Surface of crack of rod was studied. An investigation of fracture mechanism between matrix and fiber was analyzed by SEM (Scanning electron microscopy) method. A poor adhesion between the matrix and fibers was also shown for composites analyzing SEM photos. The promising tensile properties of the presented basalt fibers composites have shown their great potential as alternative classical composites.

  8. Basic rocks in Finland

    International Nuclear Information System (INIS)

    Piirainen, T.; Gehoer, S.; Iljina, M.; Kaerki, A.; Paakkola, J.; Vuollo, J.

    1992-10-01

    Basic igneous rocks, containing less than 52% SiO 2 , constitute an important part of the Finnish Archaean and Proterozoic crust. In the Archaean crust exist two units which contain the majority of the basic rocks. The Arcaean basic rocks are metavolcanics and situated in the Greenstone Belts of Eastern Finland. They are divided into two units. The greenstones of the lower one are tholeiites, komatiites and basaltic komatiites. The upper consists of bimodal series of volcanics and the basic rocks of which are Fe-tholeiites, basaltic komatiites and komatiites. Proterozoic basic rocks are divided into seven groups according to their ages. The Proterozoic igneous activity started by the volominous basic magmatism 2.44 Ga ago. During this stage formed the layered intrusions and related dykes in the Northern Finland. 2.2 Ga old basic rocks are situated at the margins of Karelian formations. 2.1 Ga aged Fe-tholeiitic magmatic activity is widespread in Eastern and Northern Finland. The basic rocks of 1.97 Ga age group are met within the Karelian Schist Belts as obducted ophiolite complexes but they occur also as tholeiitic diabase dykes cutting the Karelian schists and Archean basement. The intrusions and the volcanics of the 1.9 Ga old basic igneous activity are mostly encountered around the Granitoid Complex of Central Finland. Subjotnian, 1.6 Ga aged tholeiitic diabases are situated around the Rapakivi massifs of Southern Finland, and postjotnian, 1.2 Ga diabases in Western Finland where they form dykes cutting Svecofennian rocks

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Changes of freshwater-lens thickness in basaltic island aquifers overlain by thick coastal sediments

    Science.gov (United States)

    Rotzoll, Kolja; Oki, Delwyn S.; El-Kadi, Aly I.

    2010-01-01

    Freshwater-lens thickness and long-term changes in freshwater volume in coastal aquifers are commonly assessed through repeated measurement of salinity profiles from monitor wells that penetrate into underlying salt water. In Hawaii, the thickest measured freshwater lens is currently 262 m in dike-free, volcanic-rock aquifers that are overlain by thick coastal sediments. The midpoint depth (depth where salinity is 50% salt water) between freshwater and salt water can serve as an indicator for freshwater thickness. Most measured midpoints have risen over the past 40 years, indicating a shrinking lens. The mean rate of rise of the midpoint from 1999–2009 varied locally, with faster rates in highly developed areas (1.0 m/year) and slower rates in less developed areas (0.5 m/year). The thinning of the freshwater lenses is the result of long-term groundwater withdrawal and reduced recharge. Freshwater/salt-water interface locations predicted from measured water levels and the Ghyben-Herzberg principle may be deeper than measured midpoints during some periods and shallower during other periods, although depths may differ up to 100 m in some cases. Moreover, changes in the midpoint are slower than changes in water level. Thus, water levels may not be a reliable indicator of the amount of freshwater in a coastal aquifer.

  14. Constraining the potential temperature of the Archaean mantle: A review of the evidence from komatiites

    Science.gov (United States)

    Nisbet, E. G.; Cheadle, M. J.; Arndt, N. T.; Bickle, M. J.

    1993-09-01

    The maximum potential temperature of the Archaean mantle is poorly known, and is best constrained by the MgO contents of komatiitic liquids, which are directly related to eruptive temperatures. However, most Archaean komatiites are significantly altered and it is difficult to assess the composition of the erupted liquid. Relatively fresh lavas from the SASKMAR suite, Belingwe Greenstone Belt, Zimbabwe (2.7 Ga) include chills of 25.6 wt.% MgO, and olivines ranging to Fo 93.6, implying eruption at around 1520°C. A chill sample from Alexo Township, Ontario (also 2.7 Ga) is 28 wt.% MgO, and associated olivines range to Fo 94.1, implying eruption at 1560°C. However, inferences of erupted liquids containing 32-33 wt.% MgO, from lavas in the Barberton Greenstone Belt, South Africa (3.45 Ga) and from the Perseverance Complex, Western Australia (2.7 Ga) may be challenged on the grounds that they contain excess (cumulate) olivine, or were enriched in Mg during alteration or metamorphism. Re-interpretation of olivine compositions from these rocks shows that they most likely contained a maximum of 29 wt.% MgO corresponding to an eruption temperature of 1580°C. This composition is the highest liquid MgO content of an erupted lava that can be supported with any confidence. The hottest modern magma, on Gorgona Island (0.155 Ga) contained 18-20% MgO and erupted at circa 1400°C. If 1580°C is taken as the temperature of the most magnesian known eruption, then the source mantle from which the liquids rose would have been at up to 2200°C at pressures of 18 GPa corresponding to a mantle potential temperature of 1900°C. These temperatures are in excess of the mantle temperatures predicted by secular cooling models, and thus komatiites can only be formed in hot rising convective jets in the mantle. This result requires that Archaean mantle jets may have been 300°C hotter than the Archaean ambient mantle temperature. This temperature difference is similar to the 200-300

  15. 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

  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. Thickness of surficial sediment at and near the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Anderson, S.R.; Liszewski, M.J.; Ackerman, D.J.

    1996-06-01

    Thickness of surficial sediment was determined from natural-gamma logs in 333 wells at and near the Idaho National Engineering Laboratory in eastern Idaho to provide reconnaissance data for future site-characterization studies. Surficial sediment, which is defined as the unconsolidated clay, silt, sand, and gravel that overlie the uppermost basalt flow at each well, ranges in thickness from 0 feet in seven wells drilled through basalt outcrops east of the Idaho Chemical Processing Plant to 313 feet in well Site 14 southeast of the Big Lost River sinks. Surficial sediment includes alluvial, lacustrine, eolian, and colluvial deposits that generally accumulated during the past 200 thousand years. Additional thickness data, not included in this report, are available from numerous auger holes and foundation borings at and near most facilities

  18. Near-UV Transmittance of Basalt Dust as an Analog of the Martian Regolith: Implications for Sensor Calibration and Astrobiology

    Directory of Open Access Journals (Sweden)

    J. Martínez-Frías

    2006-06-01

    Full Text Available The Martian regolith is exposed to solar irradiation in the near-UV (200-390 nm.Basalt is one of the main components of the dust on Mars surface. The near-UV irradiationof basalt dust on Mars is simulated experimentally in order to determine the transmittance asa function of the mass and thickness of the dust. This data can serve to quantify theabsorption of dust deposited on sensors aiming to measure the UV intensity on Marssurface. The minimum thickness of the dust that corresponds to near-zero-transmittance inthe near-UV is measured. Hypothetical Martian microorganisms living on the dusty regolithat deeper layers would be preserved from the damaging solar UV irradiation.

  19. Did the formation of D″ cause the Archaean-Proterozoic transition?

    Science.gov (United States)

    Campbell, Ian H.; Griffiths, Ross W.

    2014-02-01

    The MgO content of the highest MgO plume-related komatiites and picrites remained constant at 32±2.5% between 3.5 and 2.7 Ga, then fell to 21±3% by ca. 2.0 Ga, a value similar to the present day value. Because there is a linear relationship between the liquidus temperature of dry magmas and their MgO content this observation implies that the temperature of mantle plumes changed little between 3.5 and 2.7 Ga, and then fell by 200-250 °C between 2.7 and 2.0 Ga to a temperature similar to that of present plumes. We suggest that Archaean plumes originate from the core-mantle boundary and that their temperature remained constant because the temperature of the outer core was buffered by solidification of the Fe-Ni inner core. At about 2.7 Ga dense former basaltic crust began to accumulate at the core and eventually covered it to produce an insulating layer that reduced the heat flux out of the core and lowered the temperature of mantle plumes. The temperature of mantle plumes fell as the dense layer above the core thickened until it exceeded the critical thickness required for convection. Because heat is transferred rapidly across the convecting part of the insulating layer, any further increase in its thickness by the addition more basaltic material has no influence on the temperature at the top of the layer, which is the source of Post-Archaean mantle plumes. We equate the dense layer above the core with the seismically identified layer D″. Our analyses suggest the drop in plume temperatures produced by a dense insulating layer above the core will be about 40% once it starts to convect, which is consistent with the observed drop inferred from the decrease in the MgO content of komatiites and picrites at that time.

  20. High renewable content sandwich structures based on flax-basalt hybrids and biobased epoxy polymers

    Science.gov (United States)

    Colomina, S.; Boronat, T.; Fenollar, O.; Sánchez-Nacher, L.; Balart, R.

    2014-05-01

    In the last years, a growing interest in the development of high environmental efficiency materials has been detected and this situation is more accentuated in the field of polymers and polymer composites. In this work, green composite sandwich structures with high renewable content have been developed with core cork materials. The base resin for composites was a biobased epoxy resin derived from epoxidized vegetable oils. Hybrid basalt-flax fabrics have been used as reinforcements for composites and the influence of the stacking sequence has been evaluated in order to optimize the appropriate laminate structure for the sandwich bases. Core cork materials with different thickness have been used to evaluate performance of sandwich structures thus leading to high renewable content composite sandwich structures. Results show that position of basalt fabrics plays a key role in flexural fracture of sandwich structures due to differences in stiffness between flax and basalt fibers.

  1. Asthenosphere versus lithosphere as possible sources for basaltic magmas erupted during formation of the Red Sea

    International Nuclear Information System (INIS)

    Altherr, R.; Henjes-Kunst, F.; Baumann, A.

    1990-01-01

    Representative basalts from the axial trough of the Red Sea and from volcanic fields of the Arabian Peninsula ranging in composition from N-type MORB to basanite and in age from Early Miocene to Recent show a limited variation in their isotopic compositions: 87 Sr/ 86 Sr = 0.70240-0.70361, 206 Pb/ 204 Pb = 18.040-19.634, 207 Pb/ 204 Pb = 15.496-15.666, 208 Pb/ 204 Pb = 37.808-39.710, 143 Nd/ 144 Nd = 0.513194-0.512670. There is a poorly constrained correlation between chemical composition and isotope ratios: with increasing alkalinity, Sr and Pb isotope ratios increase and the Nd isotope ratio tends to decrease. In Pb isotope variation diagrams most of the basalts plot significantly above the NHRLs, irrespective of tectonic setting, i.e. thickness of underlying crust and/or lithosphere. MORBs from the axial trough of the Red Sea have higher Pb isotope ratios for a given 87 Sr/ 86 Sr than MORBs from the Indian Ocean ridges, including the Carlsberg Ridge. It is therefore suggested that both spreading ridges tap different convective systems in the asthenosphere. The tectonic setting of the basalts is reflected in their Nd-Sr isotope characteristics. Basalts from areas where the continental lithosphere is drastically thinned or absent (i.e. Red Sea axial trough and coastal plain, Afar) plot along a reference line defined by N-type MORB and Tristan da Cunha. Basalts erupted in areas with Pan-African crust of normal thickness and moderately thinned lithospheric mantle (i.e. rift shoulder) are characterized by relative low 143 Nd/ 144 Nd ratios and plot below the reference line towards an EM I component which is also found in the subcontinental lithospheric mantle. These differences in the Nd-Sr isotopic compositions of the basalts are independent of bulk-rock chemistry and are therefore controlled by tectonic setting alone. (orig./WL)

  2. 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.

  3. 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.

  4. Petrophysical characteristics of basalt in the vadose zone, Idaho National Engineering Laboratory, Eastern Snake River Plain, Idaho

    International Nuclear Information System (INIS)

    Knutson, C.F.; Harrison, W.E.; Smith, R.P.

    1989-01-01

    We have used a core characterization system to measure bulk densities, porosities, and permeabilities of basalt lavas from the vadose zone at the Idaho National Engineering Laboratory (INEL). At the INEL, basalt lava flows with intercalated alluvial, aeolian, and lacustrine sediments extend to depths of one kilometer or more. Individual lava flows are generally less than 15 meters thick and commonly have vesicular tops and bottoms with massive basalt in their interiors. Petrophysical characterization is essential to an understanding of fluid movement in the vadose zone and in the saturated zone. Many hundreds of closely spaced permeability/porosity/bulk density measurements have defined the variability of these parameters within and between individual basalt flows. Based on geological logging and porosity/permeability measurements made on many hundred feet of core, we feel that a rather sophisticated and rigorous logging program is necessary to characterize these complex and highly variable basaltic flow units. This paper endeavors to provide a petrophysical/geological conceptual model of the Snake River Plain basalts from the vadose zone under the Radioactive Waste Management Complex area at the INEL. We hope that this model will aid in subsequent geotechnical logging in this portion of the Eastern Snake River Plain. 8 refs., 14 figs., 2 tabs

  5. 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.

  6. 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)

  7. 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)

  8. 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

  9. 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

  10. Hf-Nd isotope constraints on the origin of the Cretaceous Caribbean plateau and its relationship to the Galápagos plume

    Science.gov (United States)

    Thompson, P. M. E.; Kempton, P. D.; White, R. V.; Kerr, A. C.; Tarney, J.; Saunders, A. D.; Fitton, J. G.; McBirney, A.

    2004-01-01

    Formation of the Cretaceous Caribbean plateau, including the komatiites of Gorgona, has been linked to the currently active Galápagos hotspot. We use Hf-Nd isotopes and trace element data to characterise both the Caribbean plateau and the Galápagos hotspot, and to investigate the relationship between them. Four geochemical components are identified in the Galápagos mantle plume: two 'enriched' components with ɛHf and ɛNd similar to enriched components observed in other mantle plumes, one moderately enriched component with high Nb/Y, and a fourth component which most likely represents depleted MORB source mantle. The Caribbean plateau basalt data form a linear array in Hf-Nd isotope space, consistent with mixing between two mantle components. Combined Hf-Nd-Pb-Sr-He isotope and trace element data from this study and the literature suggest that the more enriched Caribbean end member corresponds to one or both of the enriched components identified on Galápagos. Likewise, the depleted end member of the array is geochemically indistinguishable from MORB and corresponds to the depleted component of the Galápagos system. Enriched basalts from Gorgona partially overlap with the Caribbean plateau array in ɛHf vs. ɛNd, whereas depleted basalts, picrites and komatiites from Gorgona have a high ɛHf for a given ɛNd, defining a high- ɛHf depleted end member that is not observed elsewhere within the Caribbean plateau sequences. This component is similar, however, in terms of Hf-Nd-Pb-He isotopes and trace elements to the depleted plume component recognised in basalts from Iceland and along the Reykjanes Ridge. We suggest that the Caribbean plateau represents the initial outpourings of the ancestral Galápagos plume. Absence of a moderately enriched, high Nb/Y component in the older Caribbean plateau (but found today on the island of Floreana) is either due to changing source compositions of the plume over its 90 Ma history, or is an artifact of limited sampling. The

  11. Neoarchean granite-greenstone belts and related ore mineralization in the North China Craton: An overview

    Directory of Open Access Journals (Sweden)

    Li Tang

    2018-05-01

    Full Text Available Tectonic processes involving amalgamations of microblocks along zones of ocean closure represented by granite-greenstone belts (GGB were fundamental in building the Earth's early continents. The crustal growth and cratonization of the North China Craton (NCC are correlated to the amalgamation of microblocks welded by 2.75–2.6 Ga and ∼2.5 Ga GGBs. The lithological assemblages in the GGBs are broadly represented by volcano-sedimentary sequences, subduction-collision related granitoids and bimodal volcanic rocks (basalt and dacite interlayered with minor komatiites and calc-alkalic volcanic rocks (basalt, andesite and felsic rock. The geochemical features of meta-basalts in the major GGBs of the NCC display affinity with N-MORB, E-MORB, OIB and calc-alkaline basalt, suggesting that the microblocks were separated by oceanic realm. The granitoid rocks display arc signature with enrichment of LILE (K, Rb, Sr, Ba and LREE, and depletion of HFSE (Nb, Ta, Th, U, Ti and HREE, and fall in the VAG field. The major mineralization includes Neoarchean BIF-type iron and VMS-type Cu-Zb deposits and these, together with the associated supracrustal rocks possibly formed in back-arc basins or arc-related oceanic slab subduction setting with or without input from mantle plumes. The 2.75–2.60 Ga TTG rocks, komatiites, meta-basalts and metasedimentary rocks in the Yanlingguan GGB are correlated to the upwelling mantle plume with eruption close to the continental margin within an ocean basin. The volcano-sedimentary rocks and granitoid rocks in the late Neoarchean GGBs display formation ages of 2.60–2.48 Ga, followed by metamorphism at 2.52–2.47 Ga, corresponding to a typical modern-style subduction-collision system operating at the dawn of Proterozoic. The late Neoarchean komatiite (Dongwufenzi GGB, sanukitoid (Dongwufenzi GGB and Western Shandong GGB, BIF (Zunhua GGB and VMS deposit (Hongtoushan-Qingyuan-Helong GGB have closer connection to a combined

  12. Osmium Isotopic Evolution of the Mantle Sources of Precambrian Ultramafic Rocks

    Science.gov (United States)

    Gangopadhyay, A.; Walker, R. J.

    2006-12-01

    The Os isotopic composition of the modern mantle, as recorded collectively by ocean island basalts, mid- oceanic ridge basalts (MORB) and abyssal peridotites, is evidently highly heterogeneous (γ Os(I) ranging from +25). One important question, therefore, is how and when the Earth's mantle developed such large-scale Os isotopic heterogeneities. Previous Os isotopic studies of ancient ultramafic systems, including komatiites and picrites, have shown that the Os isotopic heterogeneity of the terrestrial mantle can be traced as far back as the late-Archean (~ 2.7-2.8 Ga). This observation is based on the initial Os isotopic ratios obtained for the mantle sources of some of the ancient ultramafic rocks determined through analyses of numerous Os-rich whole-rock and/or mineral samples. In some cases, the closed-system behavior of these ancient ultramafic rocks was demonstrated via the generation of isochrons of precise ages, consistent with those obtained from other radiogenic isotopic systems. Thus, a compilation of the published initial ^{187}Os/^{188}Os ratios reported for the mantle sources of komatiitic and picritic rocks is now possible that covers a large range of geologic time spanning from the Mesozoic (ca. 89 Ma Gorgona komatiites) to the Mid-Archean (e.g., ca. 3.3 Ga Commondale komatiites), which provides a comprehensive picture of the Os isotopic evolution of their mantle sources through geologic time. Several Precambrian komatiite/picrite systems are characterized by suprachondritic initial ^{187}Os/^{188}Os ratios (e.g., Belingwe, Kostomuksha, Pechenga). Such long-term enrichments in ^{187}Os of the mantle sources for these rocks may be explained via recycling of old mafic oceanic crust or incorporation of putative suprachondritic outer core materials entrained into their mantle sources. The relative importance of the two processes for some modern mantle-derived systems (e.g., Hawaiian picrites) is an issue of substantial debate. Importantly, however, the

  13. Miocene Basaltic Lava Flows and Dikes of the Intervening Area Between Picture Gorge and Steens Basalt of the CRBG, Eastern Oregon

    Science.gov (United States)

    Cahoon, E. B.; Streck, M. J.

    2016-12-01

    Mid-Miocene basaltic lavas and dikes are exposed in the area between the southern extent of the Picture Gorge Basalt (PGB) and the northern extent of Steens Basalt in a wide corridor of the Malheur National Forest, eastern Oregon. An approximate mid-Miocene age of sampled basaltic units is indicated by stratigraphic relationships to the 16 Ma Dinner Creek Tuff. Lavas provide an opportunity to extend and/or revise distribution areas of either CRBG unit and explore the petrologic transition between them. The PGB and the Steens Basalt largely represent geochemically distinct tholeiitic units of the CRBG; although each unit displays internal complexity. Lavas of PGB are relatively primitive (MgO 5-9 wt.%) while Steens Basalt ranges in MgO from >9 to 3 wt.% but both units are commonly coarsely porphyritic. Conversely, Steens Basalt compositions are on average more enriched in highly incompatible elements (e.g. Rb, Th) and relatively enriched in the lesser incompatible elements (e.g. Y, Yb) compared to the Picture Gorge basalts. These compositional signatures produce inclined and flat patterns on mantle-normalized incompatible trace element plots but with similar troughs and spikes, respectively. New compositional data from our study area indicate basaltic lavas can be assigned as PGB lava flows and dikes, and also to a compositional group chemically distinct between Steens Basalt and PGB. Distribution of lava flows with PGB composition extend this CRBG unit significantly south/southeast closing the exposure gap between PGB and Steens Basalt. We await data that match Steens Basalt compositions but basaltic lavas with petrographic features akin to Steens Basalt have been identified in the study area. Lavas of the transitional unit share characteristics with Upper Steens and Picture Gorge basalt types, but identify a new seemingly unique composition. This composition is slightly more depleted in the lesser incompatible elements (i.e. steeper pattern) on mantle normalized

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

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

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

  15. Komatiites and nickel sulfide ores of the Black Swan area, Yilgarn Craton, Western Australia. 4. Platinum group element distribution in the ores, and genetic implications

    Science.gov (United States)

    Barnes, Stephen J.

    2004-11-01

    The Black Swan komatiite sequence, in the Eastern Goldfields province of the Archaean Yilgarn Craton in Western Australia, is a body of dominantly olivine-rich cumulates with lesser volumes of spinifex textured rocks, interpreted as a section through an extensive komatiite lava flow field. The sequence hosts a number of nickel sulfide orebodies, including the Silver Swan massive shoot and the Cygnet and Black Swan disseminated orebodies. The massive sulfide orebodies of the Black Swan Succession are pervasively depleted in all platinum group elements (PGEs), particularly Pt and Pd, despite very high Ni contents. This depletion cannot be explained by R-factor variations, which would also require relatively low Ni tenors. The PGE depletion could be explained in part if the ores are enriched in a monosulfide solid solution (MSS) cumulate component, but requires some additional fractional segregation of sulfide melt upstream from the site of deposition. The Silver Swan orebody shows a remarkably consistent vertical zonation in PGE contents, particularly in Ir, Ru, Rh, Os, which increase systematically from very low levels at the stratigraphic base of the sulfide body to maxima corresponding roughly with the top of a lower layer of the orebody rich in silicate inclusions. Platinum shows the opposite trend, but is somewhat modified by remobilisation during talc carbonate alteration. A similar pattern is also observed in the adjacent White Swan orebody. This zonation is interpreted and modelled as the result of fractional crystallisation of MSS from the molten sulfide pool. The strong IPGE depletion towards the base of the orebody may be a consequence of sulfide liquid crystallisation in an inverted thermal gradient, between a thin rapidly cooling upper rind of komatiite lava and a hot substrate.

  16. Basalts of the Khodzhirbulak Suite and Assessment their Feasibility for Basalt Fiber (Surkhantau Mountains, Southwestern Shoots of the Hissar Ridge

    Directory of Open Access Journals (Sweden)

    N. M. Khakberdyev

    2017-06-01

    Full Text Available The results of preliminary assessment of basalt of the Khodzhirbulakskoy Suite of Surkhantau Mountains for the basalt fiber production are presented. According to petrographic study, the rocks are described as basalts of amygdaloidal structure. On the base of content of the amount of glassy form and nodular calcite, three groups of basalts were identified. The inverse relationship between the bulk content of the volcanic rock and the content of calcite: the greater volume of volcanic rocks, the less content of calcite, and vice versa. The basalt material demonstrates average pH module of 3.52.

  17. 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

  18. Preliminary uncertainty analysis of pre-waste-emplacement groundwater travel times for a proposed repository in basalt

    International Nuclear Information System (INIS)

    Clifton, P.M.; Arnett, R.C.

    1984-01-01

    Preliminary uncertainty analyses of pre-waste-emplacement groundwater travel times are presented for a potential high-level nuclear waste repository in the deep basalts beneath the Hanford Site, Washington State. The uncertainty analyses are carried out by means of a Monte Carlo technique, which requires the uncertain inputs to be described as either random variables or spatial stochastic processes. Pre-waste-emplacement groundwater travel times are modeled in a continuous, flat-lying basalt flow top that is assumed to overlie the repository horizon. Two-dimensional, steady state groundwater flow is assumed, and transmissivity, effective thickness, and regional hydraulic gradient are considered as uncertain inputs. Groundwater travel time distributions corresponding to three groundwater models are presented and compared. Limitations of these preliminary simulation results are discussed in detail

  19. 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.

  20. Quickly erupted volcanic sections of the Steens Basalt, Columbia River Basalt Group: Secular variation, tectonic rotation, and the Steens Mountain reversal

    Science.gov (United States)

    Jarboe, Nicholas A.; Coe, Robert S.; Renne, Paul R.; Glen, Jonathan M. G.; Mankinen, Edward A.

    2008-01-01

    The Steens Basalt, now considered part of the Columbia River Basalt Group (CRBG), contains the earliest eruptions of this magmatic episode. Lava flows of the Steens Basalt cover about 50,000 km2 of the Oregon Plateau in sections up to 1000 m thick. The large number of continuously exposed, quickly erupted lava flows (some sections contain over 200 flows) allows for small loops in the magnetic field direction paths to be detected. For volcanic rocks, this detail and fidelity are rarely found outside of the Holocene and yield estimates of eruption durations at our four sections of ∼2.5 ka for 260 m at Pueblo Mountains, 0.5 to 1.5 ka for 190 m at Summit Springs, 1–3 ka for 170 m at North Mickey, and ∼3 ka for 160 m at Guano Rim. That only one reversal of the geomagnetic field occurred during the eruption of the Steens Basalt (the Steens reversal at approximately 16.6 Ma) is supported by comparing 40Ar/39Ar ages and magnetic polarities to the geomagnetic polarity timescale. At Summit Springs two 40Ar/39Ar ages from normal polarity flows (16.72 ± ± 0.29 Ma (16.61) and 16.92 ± ± 0.52 Ma (16.82); ± ± equals 2σ error) place their eruptions after the Steens reversal, while at Pueblo Mountains an 40Ar/39Ar age of 16.72 ± ± 0.21 Ma (16.61) from a reverse polarity flow places its eruption before the Steens reversal. Paleomagnetic field directions yielded 50 nontransitional directional-group poles which, combined with 26 from Steens Mountain, provide a paleomagnetic pole for the Oregon Plateau of 85.7°N, 318.4°E, K = 15.1, A95 = 4.3. Comparison of this new pole with a reference pole derived from CRBG flows from eastern Washington and a synthetic reference pole for North America derived from global data implies relative clockwise rotation of the Oregon Plateau of 7.4 ± 5.0° or 14.5 ± 5.4°, respectively, probably due to northward decreasing extension of the basin and range.

  1. Life and Death of a Flood Basalt: Evolution of a Magma Plumbing System in the Ethiopian Low-Ti Flood Basalt Province

    Science.gov (United States)

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

    2017-12-01

    Continental flood basalt provinces (CFBPs), which are thought to preserve the magmatic record of an impinging mantle plume head, offer spatial and temporal insight into melt generation processes in Large Igneous Provinces (LIPs). Despite the utility of CFBPs in probing the composition of mantle plumes, these basalts typically erupt fractionated compositions, suggestive of significant residence time in the continental lithosphere. The location and duration of this residence within the continental lithosphere provides additional insights into the flux of plume-related magmas. The NW Ethiopian plateau offers a well preserved stratigraphic section from flood basalt initiation to termination, and is thus an important target for study of CFBPs. We examine petrographic and whole rock geochemical variation within a stratigraphic framework and place these observations within the context of the magmatic evolution of the Ethiopian CFBP. We observe multiple pulses of magma recharge punctuated by brief shut-down events and an overall shallowing of the magmatic plumbing system over time. Initial flows are fed by magmas that have experienced deeper fractionation (clinopyroxene dominated and lower CaO/Al2O3 for a given MgO value), likely near the crust-mantle boundary. Subsequent flows are fed by magmas that have experienced shallower fractionation (plagioclase dominated and higher CaO/Al2O3 for a given MgO value) in addition to deeper fractionated magmas. Broad changes in flow thickness and modal mineralogy are consistent with fluctuating changes in magmatic flux through a complex plumbing system and indicate pulsed magma flux and an overall shallowing of the magmatic plumbing system over time. Pulses of less differentiated magmas (MgO > 8 wt%) and high-An composition of plagioclase megacrysts (labradorite to bytownite) suggest a constant replenishing of new primitive magma recharging the shallow plumbing system during the main phase of flood volcanism, though the magnitude of

  2. Origin of major element chemical trends in DSDP Leg 37 basalts, Mid-Atlantic Ridge

    Science.gov (United States)

    Byerly, G.R.; Wright, T.L.

    1978-01-01

    In this paper we summarize the major element chemical variation for basalts from the Deep Sea Drilling Project Leg 37 and relate it to stratigraphic position in each of five drilling sites. Least-squares techniques are successfully used to quantify the nature and extent of alteration in these basalts, and to correct the major element analysis back to a magmatic, or alteration-free, composition on the assumption that alteration takes place in two ways: (1) secondary minerals are introduced into veins and vesicles, and (2) CO2 and H2O react with components in the rock to form a simple alteration assemblage. A chemical stratigraphy is defined for these basalts by grouping lavas whose chemistries are related by low-pressure phenocryst-liquid differentiation as identified by least-squares calculation. Major chemical-stratigraphic units are as much as 200 m thick; correlations of these units can be made between the holes at site 332 (about 100 m apart), but not between the other sites. Compositions of parental magmas are calculated by extrapolating low-pressure variations to a constant value of 9% MgO. The differences in these extrapolated compositions reflect high-pressure processes, and suggest that clinopyroxene may be an important phase in either intermediate-level fractionation of basaltic liquids, or as a residual phase during the partial melting which produces these basaltic liquids. Several of the basaltic liquids calculated as parental to the Leg 37 basalts have CaO contents greater than 14% and indicate that the oceanic mantle is richer in CaO and Al2O3 than values used in pyrolite models for the upper mantle. A model for magma generation and eruption beneath the Mid-Atlantic Ridge embodies the following characteristics: 1. (1) Separate magma batches are generated in the mantle. 2. (2) Each of these may be erupted directly or stored at shallow depth where significant fractionation takes place. Common fractionation processes are inferred to be gravitative

  3. Melt rock components in KREEPy breccia 15205: Petrography and mineral chemistry of KREEP basalts and quartz-normative mare basalts

    Science.gov (United States)

    Shervais, John W.; Vetter, Scott K.

    1993-05-01

    Many current models for the origin of lunar highland rocks feature as an essential component the assimilation of KREEPy material by primitive magmas parental to the Mg-rich suite and alkali suite plutonic rocks. Similar models have also been proposed for the origin of various mare basalt suites. However, any model which considers assimilation of KREEP an important petrologic process must sooner-or-later deal with the question: what is KREEP? Because pristine KREEP basalts are rare, and most known samples are small (e.g., 15382/15386), the geochemical variability of KREEP basalts is poorly known. Other KREEP compositions which are commonly used in these models include the hypothetical 'high-K KREEP' component of Warren and Wasson, which is derived from Apollo 14 soil data, and the 'superKREEP' quartz-monzodiorite 15405. Lunar breccia 15205 is a polymict regolith breccia that consists of approximately 20% KREEP basalt clasts and 20% quartz-normative basalt clasts in a KREEP-rich matrix. Bulk rock mixing calculations show that this sample comprises about 84% KREEP. The clasts range up to 1 cm in size, but most are considerably smaller. The primary aim is to characterize pristine KREEP basalts petrographically, to establish the range in chemical compositions of KREEP basalts, and to test models that were proposed for their origin. In addition, we may be able to extend the compositional range recognized in the quartz-normative basalt suite and cast some light on its origin as well. Preliminary whole rock geochemical data on the KREEP basalts are presented in a companion paper by M.M. Lindstrom and co-workers. Concentration is on petrography and mineral chemistry of these clasts, and the implications these data have for the origin of the different melt rock suites.

  4. Investigation of Basalt Woven Fabrics for Military Applications

    Science.gov (United States)

    2011-11-01

    investigates the use of basalt fibers in a composite along with SC-15 epoxy resin for ballistic protection. Basalt fibers are not known as a ballistic...material but rather as a structural one. Even though basalt fibers are not expected to outperform some of the higher ballistic performing materials...such as the aramid and polyethylene fibers ; however, due to the lower manufacturing costs, basalt fibers are an interesting alternative. The objective

  5. Back-arc with frontal-arc component origin of Triassic Karmutsen basalt, British Columbia, Canada

    Science.gov (United States)

    Barker, F.; Sutherland, Brown A.; Budahn, J.R.; Plafker, G.

    1989-01-01

    The largely basaltic, ???4.5-6.2-km-thick, Middle to Upper Triassic Karmutsen Formation is a prominent part of the Wrangellian sequence. Twelve analyses of major and minor elements of representative samples of pillowed and massive basalt flows and sills from Queen Charlotte and Vancouver Islands are ferrotholeiites that show a range of 10.2-3.8% MgO (as normalized, H2O- and CO2-free) and related increases in TiO2 (1.0-2.5%), Zr (43-147 ppm) and Nb (5-16 ppm). Other elemental abundances are not related simply to MgO: distinct groupings are evident in Al2O3, Na2O and Cr, but considerable scatter is present in FeO* (FeO + 0.9Fe2O3) and CaO. Some of the variation is attributed to alteration during low-rank metamorphism or by seawater - including variation of Ba, Rb, Sr and Cu, but high-field-strength elements (Sc, Ti, Y, Zr and Nb) as well as Cr, Ni, Cu and rare-earth elements (REE's) were relatively immobile. REE's show chondrite-normalized patterns ranging from light-REE depleted to moderately light-REE enriched. On eleven discriminant plots these analyses fall largely into or across fields of within-plate basalt (WIP), normal or enriched mid-ocean-ridge tholeiite (MORB) and island-arc tholeiite (IAT). Karmutsen basalts are chemically identical to the stratigraphically equivalent Nikolai Greenstone of southern Alaska and Yukon Territory. These data and the fact that the Karmutsen rests on Sicker Group island-arc rocks of Paleozoic age suggest to us that: 1. (1) the basal arc, after minor carbonate-shale deposition, underwent near-axial back-arc rifting (as, e.g., the Mariana arc rifted at different times); 2. (2) the Karmutsen basalts were erupted along this rift or basin as "arc-rift" tholeiitite; and 3. (3) after subsequent deposition of carbonates and other rocks, and Jurassic magmatism, a large fragment of this basalt-sediment-covered island arc was accreted to North America as Wrangellia. The major- and minor-elemental abundances of Karmutsen basalt is modeled

  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. Implications of 187Os isotopic heterogeneities in a mantle plume: evidence from Gorgona Island and Curaçao

    Science.gov (United States)

    Walker, Richard J.; Storey, Michael; Kerr, Andrew C.; Tarney, John; Arndt, Nicholas T.

    1999-03-01

    ocean island basalt sources and could potentially apply to the Gorgona suite. Crustal recycling, however, requires large proportions of very ancient recycled basaltic crust in the sources of the 187Os-enriched ultramafic rocks to explain the magnitude of 187Os enrichments observed. For example, addition of 20% oceanic crust to fertile mantle, and nearly 3 billion years are necessary to generate a reservoir with the Os isotopic composition of the most radiogenic komatiites. If the recycled oceanic crust was added to basalt-depleted mantle, as may be indicated by ɛ Nd values for the komatiites averaging about +10, even larger proportions of older crust are required. Large proportions of oceanic mafic crust in the sources of the 187Os-enriched komatiites, although petrologically conceivable under certain melting conditions, is unlikely here given the limited trace element and lithophile isotope system variations. These results raise questions about the efficacy of using Os isotopes to constrain the proportion of recycled oceanic crust in other plumes. Other possible mechanisms for generating 187Os-enriched mantle include invoking the existence of a 187Os-enriched lower mantle, and minor outer core-lower mantle interactions.

  8. 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

    is proved that in order to reduce a manufacturing time of long-length cylindrical shells from short basalt fibers by liquid filtration it is necessary to use the scheme of their molding from a plane of the cylinder element. Taking into account the thermal characteristics of basalt fibers and highly porous structure of the thermal insulation on the received samples are determined the real porosity, density of material and the thickness of the tubing pipe coatings.

  9. 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.

  10. Geology, geochemistry and petrology of basalts from Paraná Continental Magmatic Province in the Araguari, Uberlândia, Uberaba and Sacramento regions, Minas Gerais state, Brazil

    Directory of Open Access Journals (Sweden)

    Lucia Castanheira de Moraes

    2018-02-01

    Full Text Available Abstract: This study covers the region between the cities of Sacramento and Araguari/Uberlândia (Minas Gerais State, Brazil, where basalt flows from the Paraná Continental Magmatic Province outcrop. The investigated rocks present tholeiitic signature, with high titanium content, and are classified as Pitanga magma-type. The preserved basalt thickness is between 10 and 200 meters and individual flows do not exceed 15 meters thick. Flows were identified as sheet lobes, smaller and thinner flows units - stacked laterally and vertically forming compound lavas -, or frontal, centimetric lobes. The basalt flows show decimetric to metric intercalations of clastic sedimentary rock, with depositional characteristics that can vary from aeolian to lacustrine, and are important markers on prevailing environmental conditions. The plagioclases are dominantly labradorite and pyroxene is augite, whereas olivine can be hyalosiderite or hortonolite/ferrohortonolite. The behavior of the major, minor and trace elements is compatible with the presence of at least two parental magmas, which were subjected to fractional crystallization mainly of plagioclase, clinopyroxene, ilmenite and magnetite. There is a chemistry distinction between basalts from Sacramento to those from Araguari/Uberlândia region, the former one showing more evolved than the last one. The high (La/LuN values are indicative of partial melting of a garnet peridotite, while the Rare Earth Elements (REE values are indicative of fractional crystallization.

  11. New Insights to the Mid Miocene Calc-alkaline Lavas of the Strawberry Volcanics, NE Oregon Surrounded by the Coeval Tholeiitic Columbia River Basalt Province

    Science.gov (United States)

    Steiner, A. R.; Streck, M. J.

    2013-12-01

    The Strawberry Volcanics (SV) of NE Oregon were distributed over 3,400 km2 during the mid-Miocene and comprise a diverse volcanic suite, which span the range of compositions from basalt to rhyolite. The predominant composition of this volcanic suite is calc-alkaline (CA) basaltic andesite and andesite, although tholeiitic (TH) lavas of basalt to andesite occur as well. The coeval flood basalts of the Columbia River province surround the SV. Here we will discuss new ages and geochemical data, and present a new geologic map and stratigraphy of the SV. The SV are emplaced on top of pre-Tertiary accreted terranes of the Blue Mountain Province, Mesozoic plutonic rocks, and older Tertiary volcanic rocks thought to be mostly Oligocene of age. Massive rhyolites (~300 m thick) are exposed mainly along the western flank and underlie the intermediate composition lavas. In the southern portion of this study area, alkali basaltic lavas, thought to be late Miocene to early Pliocene in age, erupted and overlie the SV. In addition, several regional ignimbrites reach into the area. The 9.7 Ma Devine Canyon Tuff and the 7.1 Ma Rattlesnake Tuff also overlie the SV. The 15.9-15.4 Ma Dinner Creek Tuff is mid-Miocene, and clear stratigraphic relationships are found in areas where the tuff is intercalated between thick SV lava flows. All of the basalts of the SV are TH and are dominated by phenocryst-poor (≤2%) lithologies. These basalts have an ophitic texture dominated by plagioclase, clinopyroxene and olivine (often weathered to iddingsite). Basalts and basaltic andesites have olivine Fo #'s ranging from 44 at the rims (where weathered to iddingsite) and as high as 88 at cores. Pyroxene Mg #'s range from 65 to 85. Andesites of the SV are sub-alkaline, and like the basalts, are exceedingly phenocryst-poor (≤3%) with microphenocrysts of plagioclase and lesser pyroxene and olivine, which occasionally occur as crystal clots of ~1-3 mm instead of single crystals. In addition, minimal

  12. 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.

  13. Sub-basalt Imaging of Hydrocarbon-Bearing Mesozoic Sediments Using Ray-Trace Inversion of First-Arrival Seismic Data and Elastic Finite-Difference Full-Wave Modeling Along Sinor-Valod Profile of Deccan Syneclise, India

    Science.gov (United States)

    Talukdar, Karabi; Behera, Laxmidhar

    2018-03-01

    Imaging below the basalt for hydrocarbon exploration is a global problem because of poor penetration and significant loss of seismic energy due to scattering, attenuation, absorption and mode-conversion when the seismic waves encounter a highly heterogeneous and rugose basalt layer. The conventional (short offset) seismic data acquisition, processing and modeling techniques adopted by the oil industry generally fails to image hydrocarbon-bearing sub-trappean Mesozoic sediments hidden below the basalt and is considered as a serious problem for hydrocarbon exploration in the world. To overcome this difficulty of sub-basalt imaging, we have generated dense synthetic seismic data with the help of elastic finite-difference full-wave modeling using staggered-grid scheme for the model derived from ray-trace inversion using sparse wide-angle seismic data acquired along Sinor-Valod profile in the Deccan Volcanic Province of India. The full-wave synthetic seismic data generated have been processed and imaged using conventional seismic data processing technique with Kirchhoff pre-stack time and depth migrations. The seismic image obtained correlates with all the structural features of the model obtained through ray-trace inversion of wide-angle seismic data, validating the effectiveness of robust elastic finite-difference full-wave modeling approach for imaging below thick basalts. Using the full-wave modeling also allows us to decipher small-scale heterogeneities imposed in the model as a measure of the rugose basalt interfaces, which could not be dealt with ray-trace inversion. Furthermore, we were able to accurately image thin low-velocity hydrocarbon-bearing Mesozoic sediments sandwiched between and hidden below two thick sequences of high-velocity basalt layers lying above the basement.

  14. Corrosion resistance of cast irons and titanium alloys as reference engineered metal barriers for use in basalt geologic storage: a literature assessment

    International Nuclear Information System (INIS)

    Charlot, L.A.; Westerman, R.E.

    1981-07-01

    A survey and assessment of the literature on the corrosion resistance of cast irons and low-alloy titanium are presented. Selected engineering properties of cast iron and titanium are briefly described; however, the corrosion resistance of cast iron and titanium in aqueous solutions or in soils and their use in a basalt repository are emphasized. In evaluating the potential use of cast iron and titanium as structural barrier materials for long-lived nuclear waste packages, it is assumed that titanium has the general corrosion resistance to be used in relatively thin cross sections whereas the cost and availability of cast iron allows its use even in very thick cross sections. Based on this assumption, the survey showed that: The uniform corrosion of low-alloy titanium in a basalt environment is expected to be extremely low. A linear extrapolation of general corrosion rates with an added corrosion allowance suggests that a 3.2- to 6.4-mm-thick wall may have a life of 1000 yr. Pitting and crevice corrosion are not likely corrosion modes in basalt ground waters. It is also unlikely that stress corrosion cracking (SCC) will occur in the commercially pure (CP) titanium alloy or in palladiumor molybdenum-alloyed titanium materials. Low-alloy cast irons may be used as barrier metals if the environment surrounding the metal keeps the alloy in the passive range. The solubility of the corrosion product and the semipermeable nature of the oxide film allow significant uniform corrosion over long time periods. A linear extrapolation of high-temperature corrosion rates on carbon steels and corrosion rates of cast irons in soils gives an estimated metal penetration of 51 to 64 mm after 1000 yr. A corrosion allowance of 3 to 5 times that suggests that an acceptable cast iron wall may be from 178 to 305 mm thick. Although they cannot be fully assessed, pitting and crevice corrosion should not affect cast iron due to the ground-water chemistry of basalt

  15. 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.

  16. Rare earth chemistry of gold-bearing sedimentary carbonate horizons from the Abitibi Greenstone Belt, Ontario, Canada

    International Nuclear Information System (INIS)

    Gibson, I.L.; Roberts, R.G.; Reading, D.J.R.

    1984-01-01

    The ankerite, gold ore bodies of the Dome Mine, Timmins, Ontario are interflow units, 1 to 3 m thick in a sequence of tholeiitic basalts. The units consist of discontinuous layers of ferroan dolomite, chert and pyroclastic material, and laminations of iron sulfides, tourmaline, and graphite. They have been interpreted as sediments on the basis of their internal structure. Seven Rare Earth elements (REE) (Ce, Nd, Sm, Eu, Gd, Tb, Tm, Yb) were determined by instrumental neutron activation analysis, on 10 samples of carbonate material from the ankerite units. The chondrite normalized REE plots have relatively flat patterns with, in some cases, positive Europium anomalies. The flat patterns suggest that the fluids from which the carbonate precipitated was in equilibrium with volcanic rocks of tholeiitic and komatiitic composition. The positive Europium anomalies imply that the fluids were reducing at times. Such patterns are characteristic of Archaean sediments and also the precipitates associated with the discharge of hydrothermal solutions from vents on the East Pacific Rise

  17. 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

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

    Science.gov (United States)

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

    2015-08-01

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

  19. Stratigraphy, composition and form of the Deccan Basalts, Western Ghats, India

    Science.gov (United States)

    Beane, J. E.; Turner, C. A.; Hooper, P. R.; Subbarao, K. V.; Walsh, J. N.

    1986-02-01

    In the Western Ghats between latitudes 18° 20' N and 19° 15' N, 7000 km2 of Deccan Basalt have been mapped with the primary objective of establishing a flow stratigraphy as a guide to the volcanic history of the flood basalts. Using over 70 measured vertical sections, major and trace element analyses of nearly 1200 samples, and rare-earth and87Sr/86Sr determinations for over 60 samples, we divide the basalt into three subgroups and ten formations. In this paper we describe the seven principal formations in the area and the most prominent individual flows. The Kalsubai Subgroup is formed by the lower five formations, the Jawhar, Igatpuri, Neral, Thakurvadi, and Bhimashankar formations, from botton to top. In these formations amygdaloidal compound flows predominate and have a typically high MgO content, including picrite basalt (> 10% MgO) and picrite (> 18% MgO) with phenocrysts of olivine and clinopyroxene. These flows are separated by others which contain giant plagioclase phenocrysts and have more evolved chamical compositions. The Lonavala Subgroup overlies the Kalsubai and is composed of two formations, the Khandala and the Bushe. Both are readily recognized in the field and by their chemical compositions. The Wai Subgroup includes the upper three formations, the Poladpur, the Ambenali, and the Mahabaleshwar. The whole subgroup is composed of simple flows with well-developed flow tops, small phenocrysts of plagioclase, pyroxene and olivine, and relatively evolved bulk compositions. Distribution and variation in thickness of the straitigraphic units within the Western Ghats provide a first comprehensive view of the development of the Deccan volcanic edifice. The persistent southerly dip and gentle southerly plunging anticlinal form of the flows, the lensoid shape of many of the formations, and nearly randomly oriented feeder-dike system are together interpreted as evidence of a central volcanic edifice formed as the Indian plate drifted northward over a mantle

  20. The Origin of Noble Gas Isotopic Heterogeneity in Icelandic Basalts

    Science.gov (United States)

    Dixon, E. T.; Honda, M.; McDougall, I.

    2001-01-01

    Two models for generation of heterogeneous He, Ne and Ar isotopic ratios in Icelandic basalts are evaluated using a mixing model and the observed noble gas elemental ratios in Icelandic basalts,Ocean island Basalt (OIBs) and Mid-Ocean Ridge Basalt (MORBs). Additional information is contained in the original extended abstract.

  1. Iron isotopes in ancient and modern komatiites: Evidence in support of an oxidised mantle from Archean to present

    Science.gov (United States)

    Hibbert, K. E. J.; Williams, H. M.; Kerr, A. C.; Puchtel, I. S.

    2012-03-01

    The mantle of the modern Earth is relatively oxidised compared to the initially reducing conditions inferred for core formation. The timing of the oxidation of the mantle is not conclusively resolved but has important implications for the timing of the development of the hydrosphere and atmosphere. In order to examine the timing of this oxidation event, we present iron isotope data from three exceptionally well preserved komatiite localities, Belingwe (2.7 Ga), Vetreny (2.4 Ga) and Gorgona (0.089 Ga). Measurements of Fe isotope compositions of whole-rock samples are complemented by the analysis of olivine, spinel and pyroxene separates. Bulk-rock and olivine Fe isotope compositions (δ57Fe) define clear linear correlations with indicators of magmatic differentiation (Mg#, Cr#). The mean Fe isotope compositions of the 2.7-2.4 Ga and 0.089 Ga samples are statistically distinct and this difference can be explained by greater extent of partial melting represented by the older samples and higher mantle ambient temperatures in the Archean and early Proterozoic relative to the present day. Significantly, samples of all ages define continuous positive linear correlations between bulk rock δ57Fe and V/Sc and δ57Fe and V, and between V/Sc and V with TiO2, providing evidence for the incompatible behaviour of V (relative to Sc) and of isotopically heavy Fe. Partial melting models calculated using partition coefficients for V at oxygen fugacities (fO2s) of 0 and + 1 relative to the fayalite-magnetite-quartz buffer (FMQ) best match the data arrays, which are defined by all samples, from late Archean to Tertiary. These data, therefore, provide evidence for komatiite generation under moderately oxidising conditions since the late Archean, and argue against a change in mantle fO2 concomitant with atmospheric oxygenation at ~ 2.4 Ga.

  2. The Roles of the Yellowstone Hotspot and Crustal Assimilation in Generating Pleistocene-Holocene Basalts on the Eastern Snake River Plain

    Science.gov (United States)

    Mintz, H.; Chadwick, J.

    2017-12-01

    The southwest motion of the North American plate across the Yellowstone hotspot created a chain of age-progressive rhyolitic calderas over the past 16 myr. in southern Idaho, U.S. The focus of Yellowstone activity now resides in northwest Wyoming, but basaltic volcanism has continued in its wake in southern Idaho on the eastern Snake River Plain (ESRP). These younger basaltic lavas are not age progressive and have buried the Yellowstone rhyolites on the ESRP. The ultimate source of the basalts is commonly ascribed to the passage or presence of the hotspot. However, the mechanisms involved, and the relative roles of the hotspot, other mantle sources, and the North American crust in generating the ESRP basalts remain unclear and have been the subject of recent geochemical and isotopic studies. In this study, the role of crustal assimilation is addressed by analyzing the chemical and isotopic characteristics of some of the youngest Pleistocene-Holocene tholeiitic volcanic fields on the ESRP, which were erupted through varying thicknesses of continental crust. Samples were analyzed from the Hell's Half Acre flow (5,200 years old; all dates Kuntz et al., 1986, 1994), Cerro Grande flow (13,380 years), and Black Butte Crater (a.k.a. Shoshone) flow (10,130 years), which were erupted at distances from between about 200 to 300 km from the current location of the hotspot. The crust of the ESRP thins from northeast to southwest, from about 47 km at the Hells Half Acre flow to 40 km at the Black Butte Crater flow, a thickness difference of about 15%. The apparently similar tectonic and magmatic environments of the three sampled flows suggest the crustal thickness variation may be a primary influence on the magnitude of assimilation and therefore the isotopic characteristics of the lavas. The goal of this work is to constrain the relative role of assimilation and to understand the source(s) of the magmas and the Yellowstone hotspot contribution. Major elements, trace elements

  3. Experimental assessment of borehole wall drilling damage in basaltic rocks

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1986-06-01

    Ring tension tests, permeability tests, and microscopic fracture studies have been performed to investigate the borehole damage induced at low confining pressure by three drilling techniques (diamond, percussion and rotary). Specimens are drilled with three hole sizes (38, 76, and 102 mm diameter) in Pomona basalt and Grande basaltic andesite. The damaged zone is characterized in terms of fractures and fracture patterns around the hole, and in terms of tensile strength reduction of the rock around the holes. Experimental results show that the thickness of the damaged zone around the hole ranges from 0.0 to 1.7 mm. A larger drill bit induces more wall damage than does a smaller one. Different drilling techniques show different damage characteristics (intensity and distribution). Damage characteristics are governed not only by drilling parameters (bit size, weight on bit, rotational speed, diamond radius, and energy), but also by properties of the rock. The weaker rock tends to show more intense damage than does the stronger one. Cracks within grains or cleavage fractures are predominant in slightly coarser grained rock (larger than 0.5 mm grain size) while intergranular cracks are predominant in very fine grained rock (smaller than 0.01 mm grain size). The damaged zones play no significant role in the flow path around a borehole plug

  4. 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.

  5. Pressure grouting of fractured basalt flows

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. 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.

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

    Science.gov (United States)

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

    2015-01-01

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

  9. 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

  10. 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

  11. Element mobilization and redistribution under extreme tropical weathering of basalts from the Hainan Island, South China

    Science.gov (United States)

    Jiang, Ke; Qi, Hua-Wen; Hu, Rui-Zhong

    2018-06-01

    Chemical weathering of rocks has substantial influence on the global geochemical cycle. In this paper, the geochemical profile of a well-developed basalt weathering profile (>15 m thick, including soil, saprolite, semi-weathered rock and fresh basalt) on the Island of Hainan (South China) was presented. The soil and saprolite samples from this profile are characterized by high Al2O3 and Fe2O3 concentrations (up to 32.3% and 28.5%, respectively). The mineral assemblage is dominated by kaolinite, Fe-oxides/-hydroxides and gibbsite (or boehmite), indicating extensive desilicate and ferrallitic weathering. The acidic and organic-rich environment in the soil horizon may have promoted elemental remobilization and leaching. The strongest SiO2 depletion and Al2O3 enrichment at about 2.4 m deep indicate that the main kaolinite hydrolysis and gibbsite formation occurred near the soil-saprolite interface. The mild Sr reconcentration at about 3.9 m and 7.1 m deep may be attributed to secondary carbonate precipitation. Mn-oxides/-hydroxides precipitated at 6.1 m deep, accompanied by the strongest enrichment of Ba and Co. Uranium is mildly enriched in the middle part (about 7.1 m and 9.1 m deep) of the weathering profile, and the enrichment may have been caused by the decomposition of uranyl carbonates or the accumulation of zircon. Immobile element (i.e., Zr, Hf, Nb, Ta, Th and Ti) distributions at different depths are mainly controlled by secondary Fe-oxides/-hydroxides, and follow the stability sequence of Nb ≈ Ta ≈ Th > Zr ≈ Hf > Ti. The limited thickness (∼15 cm) of the semi-weathered basalt horizon at the rock-regolith interface (15.28 m deep) suggests that plagioclase and pyroxene are readily altered to kaolinite, smectite and Fe-oxides under tropical climate. The marked enrichment of transitional metals (such as Cu, Zn, Ni, and Sc) along the rock-regolith interface may have associated mainly with increasing pH values, as well as the dissolution of primary apatite

  12. High alkali-resistant basalt fiber for reinforcing concrete

    International Nuclear Information System (INIS)

    Lipatov, Ya.V.; Gutnikov, S.I.; Manylov, M.S.; Zhukovskaya, E.S.; Lazoryak, B.I.

    2015-01-01

    Highlights: • Doping of basalt fiber with ZrSiO 4 increased its alkali resistance. • Alkali treatment results in formation of protective surface layer on fibers. • Morphology and chemical composition of surface layer were investigated. • Mechanical properties of fibers were analyzed by a Weibull distribution. • Zirconia doped basalt fibers demonstrate high performance in concrete. - Abstract: Basalt glasses and fibers with zirconia content in the range from 0 to 7 wt% were obtained using ZrSiO 4 as a zirconium source. Weight loss and tensile strength loss of fibers after refluxing in alkali solution were determined. Basalt fiber with 5.7 wt% ZrO 2 had the best alkali resistance properties. Alkali treatment results in formation of protective surface layer on fibers. Morphology and chemical composition of surface layer were investigated. It was shown that alkali resistance of zirconia doped basalt fibers is caused by insoluble compounds of Zr 4+ , Fe 3+ and Mg 2+ in corrosion layer. Mechanical properties of initial and leached fibers were evaluated by a Weibull distribution. The properties of basalt fibers with ZrSiO 4 were compared with AR-glass fibers. The performance of concrete with obtained fibers was investigated

  13. Paleomagnetic Secular Variation Constraints on the Rapid Eruption of the Emeishan Continental Flood Basalts in Southwestern China and Northern Vietnam

    Science.gov (United States)

    Xu, Yingchao; Yang, Zhenyu; Tong, Ya-Bo; Jing, Xianqing

    2018-04-01

    Estimating the duration of magma eruptions using isotopic dating methods is difficult because of the intrinsic errors of the technique regarding the dated materials (such as zircon). However, the long-term variation of the geomagnetic field recorded by lava flows can be used to estimate the net duration of an eruption sequence. The Emeishan basalts at Dongchuan, with a thickness of 630 m, yielded a reliable characteristic remanent magnetization of normal polarity and which passed the fold test (Tauxe & Watson, 1994, https://doi.org/10.1016/0012-821X(94)90006-X). Stratigraphic and magnetostratigraphic correlations of the Emeishan basalts in the Dongchuan section with other sections indicate that the eruption of the Emeishan basalts at Dongchuan spans the entire normal polarity zone in the early stage of the Emeishan large igneous province. A flow-by-flow analysis of geomagnetic directions of the Emeishan basalts at Dongchuan indicates that four directional groups and fifteen individual lava directions were recorded, with a net duration (excluding quiescent intervals) of no more than 3100 years. The averaged site directions from the Emeishan basalts with normal polarity conforming to a geocentric axial dipole direction indicate that this interval is longer than 104-105 years. In addition, a magnetostratigraphic study indicates that the normal polarity interval recorded by the Emeishan basalts was shorter than 2-20 × 104 years. Thus, the total duration of the normal polarity stage of the Emeishan large igneous province was roughly 105 years. There is a possible relationship between the rapid eruption and the Late Capitanian mass extinction (259.8 ± 0.4 Ma, Henderson et al., 2012).

  14. Study on basalt fiber parameters affecting fiber-reinforced mortar

    Science.gov (United States)

    Orlov, A. A.; Chernykh, T. N.; Sashina, A. V.; Bogusevich, D. V.

    2015-01-01

    This article considers the effect of different dosages and diameters of basalt fibers on tensile strength increase during bending of fiberboard-reinforced mortar samples. The optimal dosages of fiber, providing maximum strength in bending are revealed. The durability of basalt fiber in an environment of cement, by means of microscopic analysis of samples of fibers and fiberboard-reinforced mortar long-term tests is examined. The article also compares the behavior of basalt fiber in the cement stone environment to a glass one and reveals that the basalt fiber is not subject to destruction.

  15. Surface oxidization-reduction reactions in Columbia Plateau basalts

    International Nuclear Information System (INIS)

    White, A.F.; Yee, A.

    1984-01-01

    Results are presented which define principal oxidation-reduction reactions expected between ground water and iron in the Umtanum and Cohassett basalt flows of south central Washington. Data include kinetics of aqueous iron speciation, rates of O 2 uptake and nature of oxyhydroxide precipitates. Such data are important in predicting behavior of radionuclides in basalt aquifers including determination of valence states, speciation, solubility, sorption, and coprecipitation on iron oxyhydroxide substrates and colloids. Analyses of the basalt by XPS indicates that ferrous iron is oxidized to ferric iron on the surface and that the total iron decreases as a function of pH during experimental weathering. Iron oxyhydroxide phases did not form surface coating on basalt surfaces but rather nucleated as separate plases in solution. No significant increases in Cs or Sr sorption were observed with increased weathering of the basalt. Concurrent increases in Fe(II) and decreases in Fe(III) in slightly to moderately acid solutions indicated continued oxidization of ferrous iron in the basalt. At neutral to basic pH, Fe(II) was strongly sorbed onto the basalt surface (Kd = 6.5 x 10 -3 1 x m 2 ) resulting in low dissolved concentrations even under anoxic conditions. The rate of O 2 uptake increased with decreasing pH. Diffusion rates (-- 10 -14 cm 2 x s -1 ), calculated using a one-dimensional analytical model, indicate grain boundary diffusion. Comparisons of Eh values calculated by Pt electrode, dissolved O 2 and Fe(II)/Fe(III) measurements showed considerable divergence, with the ferric-ferrous couple being the preferred method of estimating Eh

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

    International Nuclear Information System (INIS)

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

    1987-12-01

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

  17. Geochemical and Fluid Dynamic Investigations into the Nature of Chemical Heterogeneity in the Earth’s Mantle

    Science.gov (United States)

    1992-09-01

    Table 2 and plotted in Figs. 1 and 2. Also plotted in Figure 1 are Re and Os concentration data for basalts and komatiites from Gorgona Island (Walker...tholeiites from Gorgona Island (Walker et al., 1991). Some of the lowest Re concentrations are probably due to dilution of the melt with phenocrysts (ex. MGA-B...M. Echeverria, S. B. Shirey and M. F. [Horan (1991) Re-Os isotopic constraints on the origin of volcanic rocks, Gorgona Island, Columbia: Os

  18. 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....

  19. Evaluation of residual strength in the basalt fiber reinforced composites under impact damage

    Science.gov (United States)

    Kim, Yun-Hae; Lee, Jin-Woo; Moon, Kyung-Man; Yoon, Sung-Won; Baek, Tae-Sil; Hwang, Kwang-Il

    2015-03-01

    Composites are vulnerable to the impact damage by the collision as to the thickness direction, because composites are being manufactured by laminating the fiber. The understanding about the retained strength after the impact damage of the material is essential in order to secure the reliability of the structure design using the composites. In this paper, we have tried to evaluate the motion of the material according to the kinetic energy and potential energy and the retained strength after impact damage by testing the free fall test of the basalt fiber reinforced composite in the limelight as the environment friendly characteristic.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. Extended correlation of the Paleogene Faroe Islands and East Greenland plateau basalts

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin

    2008-01-01

    on the Faroe Islands but with a lot lower intensity than on the other side of the rift. This demonstrates that large parts of the km-thick volcanic successions of the North Atlantic LIP developed in parallel on the juxtaposed rifted continental margins during break-up, although the centre of eruptions moved......New analytical data are presented for 13 enriched high-Ti tholeiitic basalts from the top of the Faroese lava pile that was formed by the time of break-up of the North Atlantic  56-55  Ma ago and are located on the eastern continental margin of the Atlantic Ocean. The samples fall in three groups...

  5. 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.

  6. 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.

  7. The 89 Ma Tortugal komatiitic suite, Costa Rica: Implications for a common geological origin of the Caribbean and Eastern Pacific region from a mantle plume

    Science.gov (United States)

    Alvarado, Guillermo E.; Denyer, Percy; Sinton, Christopher W.

    1997-05-01

    Komatiites are reported for the first time in the northern part of the Gulf of Nicoya, Costa Rica. These rocks, dated at 89.7 ± 1.4 Ma (Turonian) by 40Ar/39Ar methods, occur as a large, elongated (14 km long, 1.5 km wide) N60°W striking body in the ophiolitic Nicoya Complex. These lavas have high MgO (26% 29%), Ni, and Cr, have high CaO/Al2O3 (0.98 1.08) and moderate Al2O3/TiO2 (5.55 8.44) ratios, and are depleted in Al2O3 (4% 5.5%), K2O (0.02% 0.37%), and TiO2 (0.59% 0.9%). Although these lavas are cumulates, their geochemical composition indicates an origin from a primary komatiitic magma, with a melting temperature of 1700 °C at a depth of 150 km. Similarities in the petrology and age (88 90 Ma) of Gorgona, Curaìao, and Nicoya-Tortugal mafic and ultramafic volcanic rocks suggest that these rocks had a common origin. These occurrences suggest a single hotspot center over a large area of the Caribbean and Eastern Pacific Mesozoic region due to a major thermal anomaly in the mantle, such as a hot, rising, convective plume.

  8. 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.

  9. 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

  10. 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

  11. Numerical simulations of hydrothermal circulation resulting from basalt intrusions in a buried spreading center

    Science.gov (United States)

    Fisher, A.T.; Narasimhan, T.N.

    1991-01-01

    A two-dimensional, one by two-kilometer section through the seafloor was simulated with a numerical model to investigate coupled fluid and heat flow resulting from basalt intrusions in a buried spreading center. Boundary and initial conditions and physical properties of both sediments and basalt were constrained by field surveys and drilling in the Guaymas Basin, central Gulf of California. Parametric variations in these studies included sediment and basalt permeability, anisotropy in sediment permeability, and the size of heat sources. Faults were introduced through new intrusions both before and after cooling.Background heat input caused fluid convection at velocities ≤ 3 cm a−1 through shallow sediments. Eighty to ninety percent of the heat introduced at the base of the simulations exited through the upper, horizontal surface, even when the vertical boundaries were made permeable to fluid flow. The simulated injection of a 25–50 m thick basalt intrusion at a depth of 250 m resulted in about 10 yr of pore-fluid expulsion through the sea-floor in all cases, leaving the sediments above the intrusions strongly underpressured. A longer period of fluid recharge followed, sometimes accompanied by reductions in total seafloor heat output of 10% in comparison to pre-intrusion values. Additional discharge-recharge events were dispersed chaotically through the duration of the cooling period. These cycles in heat and fluid flow resulted from the response of the simulated system to a thermodynamic shock, the sudden emplacement of a large heat source, and not from mechanical displacement of sediments and pore fluids, which was not simulated.Water/rock mass ratios calculated from numerical simulations are in good agreement with geochemical estimates from materials recovered from the Guaymas Basin, assuming a bulk basalt permeability value of at least 10−17 m2/(10−2 mD). The addition of faults through intrusions and sediments in these simulations did not facilitate

  12. 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

  13. Sulfur degassing due to contact metamorphism during flood basalt eruptions

    Science.gov (United States)

    Yallup, Christine; Edmonds, Marie; Turchyn, Alexandra V.

    2013-11-01

    We present a study aimed at quantifying the potential for generating sulfur-rich gas emissions from the devolatilization of sediments accompanying sill emplacement during flood basalt eruptions. The potential contribution of sulfur-rich gases from sediments might augment substantially the magma-derived sulfur gases and hence impact regional and global climate. We demonstrate, from a detailed outcrop-scale study, that sulfur and total organic carbon have been devolatilized from shales immediately surrounding a 3-m thick dolerite sill on the Isle of Skye, Scotland. Localized partial melting occurred within a few centimetres of the contact in the shale, generating melt-filled cracks. Pyrite decomposed on heating within 80 cm of the contact, generating sulfur-rich gases (a mixture of H2S and SO2) and pyrrhotite. The pyrrhotite shows 32S enrichment, due to loss of 34S-enriched SO2. Further decomposition and oxidation of pyrrhotite resulted in hematite and/or magnetite within a few cm of the contact. Iron sulfates were produced during retrogressive cooling and oxidation within 20 cm of the contact. Decarbonation of the sediments due to heating is also observed, particularly along the upper contact of the sill, where increasing δ13C is consistent with loss of methane gas. The geochemical and mineralogical features observed in the shales are consistent with a short-lived intrusion, emplaced in desulfurization, as well as decarbonation, of shales adjacent to an igneous intrusion. The liberated fluids, rich in sulfur and carbon, are likely to be focused along regions of low pore fluid pressure along the margins of the sill. The sulfur gases liberated from the sediments would have augmented the sulfur dioxide (and hydrogen sulfide) yield of the eruption substantially, had they reached the surface. This enhancement of the magmatic sulfur budget has important implications for the climate impact of large flood basalt eruptions that erupt through thick, volatile-rich sedimentary

  14. Basalt fiber reinforced polymer composites: Processing and properties

    Science.gov (United States)

    Liu, Qiang

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

  15. [Comparative carcinogenic properties of basalt fiber and chrysotile-asbestos].

    Science.gov (United States)

    Nikitina, O V; Kogan, F M; Vanchugova, N N; Frash, V N

    1989-01-01

    In order to eliminate asbestos adverse effect on workers' health it was necessary to use mineral rayon, primarily basalt fibre, instead of asbestos. During a chronic experiment on animals the oncogenicity of 2 kinds of basalt fibre was studied compared to chrysotile asbestos. The dust dose of 25 mg was twice administered by intraperitonial route. All types of dust induced the onset of intraperitonial mesotheliomas but neoplasm rates were significantly lower in the groups exposed to basalt fibre. There was no credible data on the differences between the groups exposed to various types of basalt fibre. Since the latter produced some oncogenic effect, it was necessary to develop a complex of antidust measures, fully corresponding to the measures adopted for carcinogenic dusts.

  16. Magnetostratigraphy of the Grande Ronde Basalt Pasco Basin, Washington

    International Nuclear Information System (INIS)

    Packer, D.R.; Petty, M.H.

    1979-01-01

    The paleomagnetic measurements of samples from the holes sampled have shown that there are four magnetic correlation lines, between adjacent flows in holes that have distinctly different mean stratigraphic inclinations, and two magnetic polarity boundaries that can be used for magnetic correlation in the Grande Ronde Basalt in the Pasco Basin. The results of paleomagnetic measurements of samples from the Wanapum Basalt and Saddle Mountains Basalt indicate that the potential for magnetostratigraphic correlation in these sequences is also good

  17. Similar microbial communities found on two distant seafloor basalts

    Directory of Open Access Journals (Sweden)

    Esther eSinger

    2015-12-01

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

  18. 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

  19. Technetium and neptunium reactions in basalt/groundwater systems

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.

    1985-01-01

    Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/l Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to 10 -6 mol/l and 8 x 10 -7 mol/l under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 references, 6 figures

  20. Technetium and neptunium reactions in basalt/groundwater systems

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Kelmers, A.D.; Kessler, J.H.; Clark, R.J.; Johnson, J.S. Jr.; Young, G.C.; Case, F.I.; Westmoreland, C.G.; Florida State Univ., Tallahassee)

    1984-01-01

    Sorption isotherms and apparent concentration limits for Tc(VII) and Np(V) for a variety of groundwater/basalt systems were determined using Grande Ronde basalt samples representative of the Hanford Site candidate high-level waste repository. Under oxic redox conditions (air present), little or no sorption of technetium was observed; neptunium exhibited low to moderate sorption ratios. Under anoxic redox conditions (oxygen-free), low to moderate sorption of technetium was often observed, but the extent of sorption was highly dependent upon the groundwater composition and the method of pretreatment (if any) of the basalt. Sorption isotherms for technetium under reducing redox conditions (hydrazine added) indicate an apparent concentration limit of approximately 10 -6 mol/L Tc. No apparent concentration limit was found for neptunium for concentrations in groundwater up to approx. 10 -6 mol/L and 8 x 10 -7 mol/L under oxic and reducing (hydrazine added) redox conditions, respectively. Valence control and valence analysis experiments suggest that the sorption or precipitation of Tc and Np from groundwater in the presence of basalt may result from a heterogeneous reaction occurring on the surface of the basalt. One of the critical factors of this reduction reaction appears to be the accessibility of the reactive ferrous iron component of the basalt. The laboratory simulation of groundwater redox conditions representative of the repository environment through the use of solution phase redox reagents is of questionable validity, and information obtained by such experimental methods may not be defensible for site performance assessment calculations. Anoxic experiments conducted in an argon-filled glove box appear better suited for the laboratory simulation of in situ redox conditions. 15 refs., 6 tabs

  1. 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.

  2. Basaltic volcanic episodes of the Yucca Mountain region

    International Nuclear Information System (INIS)

    Crowe, B.M.

    1990-01-01

    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

  3. Basalts and picrites from a plume-type ophiolite in the South Qilian Accretionary Belt, Qilian Orogen: Accretion of a Cambrian Oceanic Plateau?

    Science.gov (United States)

    Zhang, Yuqi; Song, Shuguang; Yang, Liming; Su, Li; Niu, Yaoling; Allen, Mark B.; Xu, Xin

    2017-05-01

    Oceanic plateaus with high-Mg rocks in the present-day oceanic crust have attracted much attention for their proposed mantle-plume origins and abnormally high mantle potential temperatures (Tp). However, equivalent rocks in ancient oceanic environments are usually poorly preserved because of deformation and metamorphism. Here we present petrological, geochronological and geochemical data for pillow lavas from Cambrian ophiolites in the Lajishan and Yongjing regions of the South Qilian Accretionary Belt (SQAB), from the southern part of the Qilian Orogen, northern China. Three rock groups can be identified geochemically: (1) sub-alkaline basalts with enriched mid- ocean ridge basalt (E-MORB) affinity; (2) alkaline basalts with oceanic island basalt (OIB) features, probably derived from partial melting of an enriched mantle source; and (3) picrites with MgO (18-22 wt%). Cr-numbers [Cr# = Cr/(Cr + Al)] of spinels from the picrites suggest 18-21% degree of partial melting at the estimated mantle potential temperature (Tp) of 1489-1600 °C, equivalent to values of Cenozoic Hawaiian picrites (1500-1600 °C). Zircons from one gabbro sample yielded a U-Pb Concordia age of 525 ± 3 Ma, suggesting the oceanic crust formed in the Cambrian. Available evidence suggests that Cambrian mantle plume activity is preserved in the South Qilian Accretionary Belt, and influenced the regional tectonics: "jamming" of the trench by thick oceanic crust explains the emplacement and preservation of the oceanic plateau, and gave rise to the generation of concomitant Ordovician inner-oceanic island arc basalts via re-organisation of the subduction zones in the region.

  4. Diffusion of hydrous species in model basaltic melt

    Science.gov (United States)

    Zhang, Li; Guo, Xuan; Wang, Qinxia; Ding, Jiale; Ni, Huaiwei

    2017-10-01

    Water diffusion in Fe-free model basaltic melt with up to 2 wt% H2O was investigated at 1658-1846 K and 1 GPa in piston-cylinder apparatus using both hydration and diffusion couple techniques. Diffusion profiles measured by FTIR are consistent with a model in which both molecular H2O (H2Om) and hydroxyl (OH) contribute to water diffusion. OH diffusivity is roughly 13% of H2Om diffusivity, showing little dependence on temperature or water concentration. Water diffusion is dominated by the motion of OH until total H2O (H2Ot) concentration reaches 1 wt%. The dependence of apparent H2Ot diffusivity on H2Ot concentration appears to be overestimated by a previous study on MORB melt, but H2Ot diffusivity at 1 wt% H2Ot in basaltic melt is still greater than those in rhyolitic to andesitic melts. The appreciable contribution of OH to water diffusion in basaltic melt can be explained by enhanced mobility of OH, probably associated with the development of free hydroxyl bonded with network-modifying cations, as well as higher OH concentration. Calculation based on the Nernst-Einstein equation demonstrates that OH may serve as an effective charge carrier in hydrous basaltic melt, which could partly account for the previously observed strong influence of water on electrical conductivity of basaltic melt.

  5. 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. ...

  6. 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...

  7. High water content in primitive continental flood basalts.

    Science.gov (United States)

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

    2016-05-04

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  8. A Brillouin scattering study of hydrous basaltic glasses: the effect of H2O on their elastic behavior and implications for the densities of basaltic melts

    Science.gov (United States)

    Wu, Lei; Yang, De-Bin; Liu, Jun-Xiu; Hu, Bo; Xie, Hong-Sen; Li, Fang-Fei; Yu, Yang; Xu, Wen-Liang; Gao, Chun-Xiao

    2017-06-01

    Hydrous basalt glasses with water contents of 0-6.82% were synthesized using a multi-anvil press at 1.0-2.0 GPa and 1200-1400 °C. The starting materials were natural Mesozoic basalts from the eastern North China Craton (NCC). Their sound velocities and elastic properties were measured by Brillouin scattering spectroscopy. The longitudinal ( V P) and shear ( V S) wave velocities decreased with increasing water content. Increasing the synthesis pressure resulted in the glass becoming denser, and finally led to an increase in V P. As the degree of depolymerization increased, the V P, V S, and shear and bulk moduli of the hydrous basalt glasses decreased, whereas the adiabatic compressibility increased. The partial molar volumes of water (ν) under ambient conditions were independent of composition, having values of 11.6 ± 0.8, 10.9 ± 0.6 and 11.5 ± 0.5 cm3/mol for the FX (Feixian), FW (Fuxin), and SHT (Sihetun) basalt glasses, respectively. However, the {{V}_{{{{H}}_{{2}}}{O}}} values measured at elevated temperatures and pressures are increasing with increasing temperature or decreasing pressure. The contrasting densities of these hydrous basalt melts with those previously reported for mid-ocean ridge basalt and preliminary reference Earth model data indicate that hydrous basalt melts may not maintain gravitational stability at the base of the upper mantle.

  9. Iron isotopic systematics of oceanic basalts

    Science.gov (United States)

    Teng, Fang-Zhen; Dauphas, Nicolas; Huang, Shichun; Marty, Bernard

    2013-04-01

    The iron isotopic compositions of 93 well-characterized basalts from geochemically and geologically diverse mid-ocean ridge segments, oceanic islands and back arc basins were measured. Forty-three MORBs have homogeneous Fe isotopic composition, with δ56Fe ranging from +0.07‰ to +0.14‰ and an average of +0.105 ± 0.006‰ (2SD/√n, n = 43, MSWD = 1.9). Three back arc basin basalts have similar δ56Fe to MORBs. By contrast, OIBs are slightly heterogeneous with δ56Fe ranging from +0.05‰ to +0.14‰ in samples from Koolau and Loihi, Hawaii, and from +0.09‰ to +0.18‰ in samples from the Society Islands and Cook-Austral chain, French Polynesia. Overall, oceanic basalts are isotopically heavier than mantle peridotite and pyroxenite xenoliths, reflecting Fe isotope fractionation during partial melting of the mantle. Iron isotopic variations in OIBs mainly reflect Fe isotope fractionation during fractional crystallization of olivine and pyroxene, enhanced by source heterogeneity in Koolau samples.

  10. Making rhyolite in a basalt crucible

    Science.gov (United States)

    Eichelberger, John

    2016-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Jeong-Il Choi

    2015-09-01

    Full Text Available The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber’s suitability as a reinforcing fiber. Single fiber pullout tests were performed and then the tensile strength of fiber was measured according to fiber orientation. The test results showed that basalt fiber has a strong chemical bond with the cementitious matrix, 1.88 times higher than that of polyvinyl alcohol fibers with it. However, other properties of basalt fiber such as slip-hardening coefficient and strength reduction coefficient were worse than PVA and polyethylene fibers in terms of fiber bridging capacity. Theoretical fiber-bridging curves showed that the basalt fiber reinforcing system has a higher cracking strength than the PVA fiber reinforcing system, but the reinforcing system showed softening behavior after cracking.

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

    Science.gov (United States)

    Choi, Jeong-Il; Lee, Bang Yeon

    2015-09-30

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber's suitability as a reinforcing fiber. Single fiber pullout tests were performed and then the tensile strength of fiber was measured according to fiber orientation. The test results showed that basalt fiber has a strong chemical bond with the cementitious matrix, 1.88 times higher than that of polyvinyl alcohol fibers with it. However, other properties of basalt fiber such as slip-hardening coefficient and strength reduction coefficient were worse than PVA and polyethylene fibers in terms of fiber bridging capacity. Theoretical fiber-bridging curves showed that the basalt fiber reinforcing system has a higher cracking strength than the PVA fiber reinforcing system, but the reinforcing system showed softening behavior after cracking.

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

    OpenAIRE

    URKHANOVA Larisa Alekseevna; LKHASARANOV Solbon Aleksandrovich; ROZINA Victoria Yevgenievna; BUYANTUEV Sergey Lubsanovich; BARDAKHANOV Sergey Prokopievich

    2014-01-01

    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 ba...

  14. Dust coatings on basaltic rocks and implications for thermal infrared spectroscopy of Mars

    Science.gov (United States)

    Johnson, J. R.; Christensen, P.R.; Lucey, P.G.

    2002-01-01

    Thin coatings of atmospherically deposited dust can mask the spectral characteristics of underlying surfaces on Mars from the visible to thermal infrared wavelengths, making identification of substrate and coating mineralogy difficult from lander and orbiter spectrometer data. To study the spectral effects of dust coatings, we acquired thermal emission and hemispherical reflectance spectra (5-25 μm; 2000-400 cm-1) of basaltic andesite coated with different thicknesses of air fall-deposited palagonitic soils, fine-grained ceramic clay powders, and terrestrial loess. The results show that thin coatings (10-20 μm) reduce the spectral contrast of the rock substrate substantially, consistent with previous work. This contrast reduction continues linearly with increasing coating thickness until a "saturation thickness" is reached, after which little further change is observed. The saturation thickness of the spectrally flat palagonite coatings is ~100-120 μm, whereas that for coatings with higher spectral contrast is only ~50-75 μm. Spectral differences among coated and uncoated samples correlate with measured coating thicknesses in a quadratic manner, whereas correlations with estimated surface area coverage are better fit by linear functions. Linear mixture modeling of coated samples using the rock substrate and coating materials as end-members is also consistent with their measured coating thicknesses and areal coverage. A comparison of ratios of Thermal Emission Spectrometer (TES) spectra of dark and bright intracrater and windstreak deposits associated with Radau crater suggests that the dark windstreak material may be coated with as much as 90% areal coverage of palagonitic dust. The data presented here also will help improve interpretations of upcoming mini-TES and Thermal Emission Imaging System (THEMIS) observations of coated Mars surface materials.

  15. Growing magma chambers control the distribution of small-scale flood basalts.

    Science.gov (United States)

    Yu, Xun; Chen, Li-Hui; Zeng, Gang

    2015-11-19

    Small-scale continental flood basalts are a global phenomenon characterized by regular spatio-temporal distributions. However, no genetic mechanism has been proposed to explain the visible but overlooked distribution patterns of these continental basaltic volcanism. Here we present a case study from eastern China, combining major and trace element analyses with Ar-Ar and K-Ar dating to show that the spatio-temporal distribution of small-scale flood basalts is controlled by the growth of long-lived magma chambers. Evolved basalts (SiO2 > 47.5 wt.%) from Xinchang-Shengzhou, a small-scale Cenozoic flood basalt field in Zhejiang province, eastern China, show a northward younging trend over the period 9.4-3.0 Ma. With northward migration, the magmas evolved only slightly ((Na2O + K2O)/MgO = 0.40-0.66; TiO2/MgO = 0.23-0.35) during about 6 Myr (9.4-3.3 Ma). When the flood basalts reached the northern end of the province, the magmas evolved rapidly (3.3-3.0 Ma) through a broad range of compositions ((Na2O + K2O)/MgO = 0.60-1.28; TiO2/MgO = 0.30-0.57). The distribution and two-stage compositional evolution of the migrating flood basalts record continuous magma replenishment that buffered against magmatic evolution and induced magma chamber growth. Our results demonstrate that the magma replenishment-magma chamber growth model explains the spatio-temporal distribution of small-scale flood basalts.

  16. Isotopic signature of Madeira basaltic magmatism

    International Nuclear Information System (INIS)

    Kogarko, L.N.; Karpenko, S.F.; Bibikova, E.V.; Mato, Zh.

    2000-01-01

    Chemical composition of the basalts of Madeira Island is studied. To assess the isotopic sources of magmatism the Pb-Sr, Sm-Nd, U-Th-Pb systems were investigated in a number of basalts. It is shown that the island's rocks are characterized by the mostly deplet sources in relation to Pb-Sr and Sm-Nd systems ( 87 Sr/ 86 Sr - 0.70282-0.70292, 143 Nd/ 144 Nd - 0.52303-0.51314). Isotopic composition of lead testifies that the magmatism reservoir is some enriched. It is concluded that the magmatism of Madeira Island is a new example of world ocean island's volcanism [ru

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-01

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

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

    International Nuclear Information System (INIS)

    Ipbüker, Cagatay; Nulk, Helena; Gulik, Volodymyr; Biland, Alex; Tkaczyk, Alan Henry

    2015-01-01

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

  19. Petrology of basalts from Loihi Seamount, Hawaii

    Science.gov (United States)

    Hawkins, James; Melchior, John

    1983-12-01

    Loihi Seamount is the southeasternmost active volcano of the Emperor-Hawaii linear volcanic chain. It comprises a spectrum of basalt compositional varieties including basanite, alkali basalt, transitional basalt and tholeiite. Samples from four dredge collections made on Scripps Institution of Oceanography Benthic Expedition in October 1982 are tholeiite. The samples include highly vesicular, olivine-rich basalt and dense glass-rich pillow fragments containing olivine and augite phenocrysts. Both quartz-normative and olivine-normative tholeiites are present. Minor and trace element data indicate relatively high abundances of low partition coefficient elements (e.g., Ti, K, P. Rb, Ba, Zr) and suggest that the samples were derived by relatively small to moderate extent of partial melting, of an undepleted mantle source. Olivine composition, MgO, Cr and Ni abundances, and Mg/(Mg+Fe), are typical of moderately fractionated to relatively unfractionated "primary" magmas. The variations in chemistry between samples cannot be adequately explained by low-pressure fractional crystallization but can be satisfied by minor variations in extent of melting if a homogeneous source is postulated. Alternatively, a heterogeneous source with variable abundances of certain trace elements, or mixing of liquids, may have been involved. Data for 3He/ 4He, presented in a separate paper, implies a mantle plume origin for the helium composition of the Loihi samples. There is little variation in the helium isotope ratio for samples having different compositions and textures. The helium data are not distinctive enough to unequivocally separate the magma sources for the tholeiitic rocks from the other rock types such as Loihi alkalic basalts and the whole source region for Loihi may have a nearly uniform helium compositions even though other element abundances may be variable. Complex petrologic processes including variable melting, fractional crystallization and magma mixing may have blurred

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

    OpenAIRE

    Choi, Jeong-Il; Lee, Bang

    2015-01-01

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

  1. UTILIZATION OF BASALT FIBERS AS A RAW MATERIAL FOR CLAY CERAMIC PRODUCTION

    Directory of Open Access Journals (Sweden)

    Supawan Vichaphund

    2016-03-01

    Full Text Available This research aimed to investigate the possibility of utilization basalt fibers as a raw material for ceramic production. Both quartz and feldspar were replaced partially or entirely by basalt fiber in the range of 10-25 wt%. The mixture of ceramic powders and basalt fibers were uniaxially pressed and sintered at temperatures between 1000 and 1200°C for 1 h. The substitution of basalt fibers in ceramic compositions demonstrated the positive effect on the physical and mechanical properties. The addition of basalt fibers in an appropriate amount enhance the densification and reduce sintering temperature of clay-based ceramics (CB-0 from 1200 to 1150°C. The highest density and strength were 2.40 g/cm³ and 116 MPa, respectively, when replacing feldspar and quartz with basalt up to 20 wt% (CB-20 and sintering at 1150°C.

  2. Radionuclide sorption kinetics and column sorption studies with Columbia River basalts

    International Nuclear Information System (INIS)

    Barney, G.S.

    1983-09-01

    The kinetics of radionuclide sorption and desorption reactions in basalt-groundwater systems were evaluated at 60 degrees C using a batch equilibration method. It was found that many sorption reactions on surfaces of fresh (unaltered) basalt from the Umtanum and Cohassett flows are slow. Some reactions require more than 50 days to reach a steady state. Sorption of neptunium and uranium in oxidizing (air saturated) groundwater appears to be controlled by slow reduction of these elements by the basalt surfaces. The resulting lower oxidation states are more strongly sorbed. Technetium and selenium, which are anionic under oxidizing conditions, are not measurably sorbed on fresh basalt surfaces, but are slightly sorbed on the altered surfaces of flow top basalt. Under reducing conditions, where the groundwater contains dilute hydrazine, sorption is faster for neptunium, uranium, technetium, selenium, and lead. Plutonium sorption rates were not affected by the groundwater Eh. It was shown that radium was precipitated rather than sorbed under the conditions of these experiments. Umtanum flow top material sorbed radionuclides much faster than fresh basalt surfaces due to its greater surface area and cation exchange capacity. Desorption rates for plutonium, uranium, neptunium, technetium, and selenium were generally much less than sorption rates (especially for reducing conditions). These radionuclides are irreversibly sorbed on the basalts. 25 refs., 20 figs., 19 tabs

  3. 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

  4. 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.

  5. 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

  6. The compatibility of basalt and MgO with liquid sodium

    International Nuclear Information System (INIS)

    Jung, J.; Runge, H.

    1984-01-01

    The interaction of commercially available basalt and MgO-ceramics with liquid sodium has been investigated up to 900 0 C. The two basalt qualities even reacted with sodium at low temperatures and short exposure times. Some inserted MgO-ceramics exhibited the expected good sodium compatibility even at 900 0 C for 100 hours. The reaction mechanisms, the volume changes and the mass balance are discussed. In the thermal shock experiments, the basaltic materials were totally disintegrated while the MgO-qualities remained compact. (author)

  7. 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

  8. Antifriction basalt-plastics based on polypropylene

    Science.gov (United States)

    Bashtannik, P. I.; Ovcharenko, V. G.

    1997-05-01

    A study is made of the dependence of the mechanical and friction-engineering properties of polypropylene reinforced with basalt fibers on the viscosity of the polymer matrix. It is established that the main factors that determine the mechanical properties of the plastics are the quality of impregnation of the fibers by the binder and the residual length of the reinforcing filler in the composite after extrusion and injection molding. The material that was developed has a low friction coefficient and low rate of wear within a relatively brood range of friction conditions. The basalt-plastics can be used in the rubbing parts of machines and mechanisms subjected to dry friction.

  9. 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.

  10. Scientific results from the deepened Lopra-1 borehole, Faroe Islands: Wire-line log-based stratigraphy of flood basalts from the Lopra-1/1A well, Faroe Islands

    Directory of Open Access Journals (Sweden)

    Boldreel, Lars O.

    2006-07-01

    Full Text Available The present study shows that it is possible to use conventional borehole logs to perform a detailed lithological/stratigraphical division of a column of subaerially extruded basalt. A stratigraphical division of the subaerial flood basalts penetrated by the Lopra-1/1A well has been carried out using new wire-line logging data measured in 1996 in the interval 200–2489 m depth. Resistivity data acquired in the interval 200–2178 m depth during 1981 after the initial drilling of the Lopra-1 well have also been incorporated. Eighty-six individual flow units, 18 compound flows and two dolerite dykes have been identified by combining the NPHI porosity, RHOB density, P-, S- and Stonely-sonic transit time, calliper and resistivity logs. Fifty-two sedimentary/tuffaceous layers have also been identified using the CGR and SGR gamma ray and potassium logs in combination with the aforementioned logs. Within the flow units, sonic velocity, density and resistivity are highest in the core where porosity is lowest. This relation is reversed in the uppermost and basal zones of the flow units. The sonic velocity in the core seems to be independent of the thickness of the flow unit. Porous zones seem abundant in some cores and the total section of cores containing porous zones constitutes more than 70% of the thickness of its flow unit, but where porous zones are absent the core makes up only roughly 50% of the thickness of the flow. It is suggested that the flow units with porous cores represent aa flows (88% of the flow units and the others pahoehoe flows (12% of the flow units.The log pattern of the flow units (crust, core and basal zone is similar to log patterns reported from other basalt plateaux. However the patterns in Lopra-1/1A show a larger variation than elsewhere,suggesting that the flow units are more complex vertically than previously thought. Statistical analysis of P-, S- and Stonely-waves, RHOB, NPHI, resistivity, gamma and calliper logs has

  11. Stratigraphy of Oceanus Procellarum basalts - Sources and styles of emplacement

    Science.gov (United States)

    Whitford-Stark, J. L.; Head, J. W., III

    1980-01-01

    The basaltic fill of Oceanus Procellarum has been formally subdivided into four lithostratigraphic formations: The Repsold Formation, the Telemann Formation, the Hermann Formation, and the Sharp Formation. The Repsold Formation is composed of high-Ti basalts and pyroclastic deposits with an estimated age of 3.75 + or - 0.05 b.y. and an estimated volume of about 2.1 x 10 to the 5th cu km. This is overlain by the Telemann Formation composed of very low-Ti basalts and pyroclastic deposits with an estimated age of 3.6 + or - 0.2 b.y. and a volume of 4.2 x 10 to the 5th cu km. The Hermann Formation, composed of intermediate basalts with an estimated age of 3.3 + or - 0.3 b.y., represents the next youngest unit with an estimated volume of 2.2 x 10 to the 5th cu km. The youngest materials in Procellarum are the medium-to-high-Ti basalts comprising the Sharp Formation with an estimated age of 2.7 + or - 0.7 b.y. and a volume of 1.8 x 10 to the 4th cu km.

  12. The Acampamento Velho Formation is a succession of rhyolitic basaltic belong to the lower Paleozoic.: Geochemical characterization of the trace elements and strange lands

    International Nuclear Information System (INIS)

    De Almeida, M.; Zerfass, H.; De Lima, L.

    1998-01-01

    During at the end of Brazilian orogeny cycle (lower Paleozoic), the Camaqua basin was filled by a thick vulcanic series, named Acampamento Velho Formation , which consists of a recurrence of basaltic episodes (at the base) and the alternance of pyroclastic rocks with a rhyolitic composition TBr and Igr) in the intermediate portion and rhyolitic flows (Dr) at the top. Based on the geochemical results, especially on the trace elements such as Zr, Ti, Nb, Y, YB,Th. Ta and the REE., it is confirmed the stratigraphical succession and the depositation chronological order observed in the field. All the volcanic succession presents a behavior pattern typical of post- collisional orogenic, rocks, originated from the crustal contamination of basaltic magmas generated in an environment of the active continental margin. (author)

  13. On causal links between flood basalts and continental breakup

    Science.gov (United States)

    Courtillot, V.; Jaupart, C.; Manighetti, I.; Tapponnier, P.; Besse, J.

    1999-03-01

    Temporal coincidence between continental flood basalts and breakup has been noted for almost three decades. Eight major continental flood basalts have been produced over the last 300 Ma. The most recent, the Ethiopian traps, erupted in about 1 Myr at 30 Ma. Rifting in the Red Sea and Gulf of Aden, and possibly East African rift started at about the same time. A second trap-like episode occurred around 2 Ma and formation of true oceanic crust is due in the next few Myr. We find similar relationships for the 60 Ma Greenland traps and opening of the North Atlantic, 65 Ma Deccan traps and opening of the NW Indian Ocean, 132 Ma Parana traps and South Atlantic, 184 Ma Karoo traps and SW Indian Ocean, and 200 Ma Central Atlantic Margin flood basalts and opening of the Central Atlantic Ocean. The 250 Ma Siberian and 258 Ma Emeishan traps seem to correlate with major, if aborted, phases of rifting. Rifting asymmetry, apparent triple junctions and rift propagation (towards the flood basalt area) are common features that may, together with the relative timings of flood basalt, seaward dipping reflector and oceanic crust production, depend on a number of plume- and lithosphere- related factors. We propose a mixed scenario of `active/passive' rifting to account for these observations. In all cases, an active component (a plume and resulting flood basalt) is a pre-requisite for the breakup of a major oceanic basin. But rifting must be allowed by plate-boundary forces and is influenced by pre-existing heterogeneities in lithospheric structure. The best example is the Atlantic Ocean, whose large-scale geometry with three large basins was imposed by the impact points of three mantle plumes.

  14. Basalt stratigraphy - Pasco Basin

    International Nuclear Information System (INIS)

    Waters, A.C.; Myers, C.W.; Brown, D.J.; Ledgerwood, R.K.

    1979-10-01

    The geologic history of the Pasco Basin is sketched. Study of the stratigraphy of the area involved a number of techniques including major-element chemistry, paleomagnetic investigations, borehole logging, and other geophysical survey methods. Grande Ronde basalt accumulation in the Pasco Basin is described. An illustrative log response is shown. 1 figure

  15. Hf Isotope Evidence for Subducted Basalt and Sediment Contributions to the Eastern Trans-Mexican Volcanic Belt

    Science.gov (United States)

    Cai, Y.; Tuena, A. G.; Capra, L.; Straub, S. M.; Goldstein, S. L.; Langmuir, C. H.

    2005-12-01

    Magmas generated at thick crust continental arcs often have enriched continental crust-like trace element patterns and Pb-Sr-Nd isotope ratios that are intermediate to both upper mantle and crustal compositions. Thus it is difficult to distinguish between contributions from (a) the subducted basalt and the upper mantle wedge, and (b) subducted sediment and the continental crust. These issues have been the focus of major controversy. Here we show evidence for subduction contributions to lavas in a classic thick crust environment. In Eastern Trans-Mexican Volcanic Belt, the upper continental crust is 30 km to 45 km thick. However, primitive mafic lavas erupt on many sites across the arc. We have analyzed the subducting sediments as represented by DSDP 487, located seaward of the trench, where the lower third of the sediment column has strongly hydrothermal pelagic features and the upper two-thirds is composed of terrigenous sediments. The pelagic sediments have distinctive features that could be used to identify a subduction component in the volcanics, including high REE/Hf, negative Ce anomalies, and Nd-Hf isotopes that lie on the "seawater array" and offset from the "mantle-crust" array. We have focused on a unique series of lavas from volcano Nevado de Toluca, located southwest of Mexico City. These lavas show negative Ce anomalies coupled with low REE/Hf and Zr/Nd ratios. Hf-Nd isotope ratios show a shallow trend compared to the mantle-crust array, consistent with a pelagic component. In addition, Hf isotopes show a striking positive correlation with Ce anomalies that trend toward the pelagic sediment compositions. These and other observations provide clear evidence for a component from subducted sediment in the lavas. In addition, there is a negative correlation of Lu/Hf and Hf isotopes that requires a mixing endmember with MORB-like Hf isotope ratios but with lower than MORB Lu/Hf. This indicates a melt from eclogitic subducted basalt. Compared to other

  16. 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

  17. 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.

  18. Influence of surface modified basalt fiber on strength of cinder lightweight aggregate concrete

    Science.gov (United States)

    Xiao, Liguang; Li, Jiheng; Liu, Qingshun

    2017-12-01

    In order to improve the bonding and bridging effect between volcanic slag lightweight aggregate concrete cement and basalt fiber, The basalt fiber was subjected to etching and roughening treatment by NaOH solution, and the surface of the basalt fiber was treated with a mixture of sodium silicate and micro-silica powder. The influence of modified basalt fiber on the strength of volcanic slag lightweight aggregate concrete was systematically studied. The experimental results show that the modified basalt fiber volcanic slag lightweight aggregate concrete has a flexural strength increased by 47%, the compressive strength is improved by 16% and the toughness is increased by 27% compared with that of the non-fiber.

  19. AEGIS methodology demonstration: case example in basalt

    International Nuclear Information System (INIS)

    Dove, F.H.

    1982-01-01

    The AEGIS technology has been successfully demonstrated. For the same data, similar unpublished results have been obtained by RHO and INTERA Environmental Consultants, Inc. for contaminant transport. In addition to establishing the utility of computer codes and assessment methodology, the AEGIS technology demonstration in basalt has also produced some practical guidance for future field data gathering programs. The results of this basalt demonstration indicate that the geohydrologic systems separating the nuclear waste from the natural biosphere discharge site mitigate the consequences of the postulated fault intersection event. This analysis suggests that the basalt system satisfies the 1000- and 10,000-yr proposed standards for release to the accessible environment (limited release of 129 I and 14 C). The reader should be cautioned, however, that the results are valid only for one particular set of parameters and one postulated release scenario. A complete sensitivity analysis must be performed to evaluate the range of effects that might be observed under different release conditions and for the different range in parameters

  20. Characterization and utilization potential of basalt rock from East-Lampung district

    Science.gov (United States)

    Isnugroho, K.; Hendronursito, Y.; Birawidha, D. C.

    2018-01-01

    The aim of this research was to study the petrography and chemical properties of basalt rock from East Lampung district, Lampung province. Petrography analysis was performed using a polarization microscope, and analysis of chemical composition using X-RF method. From the analysis of basalt rock samples, the mineral composition consists of pyroxene, plagioclase, olivine, and opaque minerals. Basic mass of basalt rock samples is, composed of plagioclase and pyroxene with subhedral-anhedral shape, forming intergranular texture, and uniform distribution. Mineral plagioclase is colorless and blade shape, transformed into opaque minerals with a size of basalt rock samples, consisting of 37.76-59.64 SiO2; 10.10-20.93 Fe2O3; 11.77-14.32 Al2O3; 5.57-14.75 CaO; 5.37-9.15 MgO; 1.40-3.34 Na2O. From the calculation, obtained the value of acidity ratio (Ma) = 3.81. With these values, indicate that the basalt rock from East Lampung district has the potential to be utilized as stone wool fiber.

  1. 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.

  2. 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

  3. Basalt fiber manufacturing technology and the possibility of its use in dentistry

    International Nuclear Information System (INIS)

    Karavaeva, E; Rogozhnikov, A; Nikitin, V; Cherepennikov, Yu; Lysakov, A

    2015-01-01

    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. (paper)

  4. 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.

  5. 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

  6. Petrochemistry of a xenolith-bearing Neogene alkali olivine basalt from northeastern Iran

    Science.gov (United States)

    Saadat, Saeed; Stern, Charles R.

    2012-05-01

    A small isolated Neogene, possibly Quaternary, monogenetic alkali olivine basalt cone in northeastern Iran contains both mantle peridotite and crustal gabbroic xenoliths, as well as plagioclase megacrysts. The basaltic magma rose to the surface along pathways associated with local extension at the junction between the N-S right-lateral and E-W left-lateral strike slip faults that form the northeastern boundary of the Lut microcontinental block. This basalt is enriched in LREE relative to HREE, and has trace-element ratios similar to that of oceanic island basalts (OIB). Its 87Sr/86Sr (0.705013 to 0.705252), 143Nd/144Nd (0.512735 to 0.512738), and Pb isotopic compositions all fall in the field of OIB derived from enriched (EM-2) mantle. It formed by mixing of small melt fractions from both garnet-bearing asthenospheric and spinel-facies lithospheric mantle. Plagioclase (An26-32) megacrysts, up to 4 cm in length, have euhedral crystal faces and show no evidence of reaction with the host basalt. Their trace-element concentrations suggest that these megacrysts are co-genetic with the basalt host, although their 87Sr/86Sr (0.704796) and 143Nd/144Nd (0.512687) ratios are different than this basalt. Round to angular, medium-grained granoblastic meta-igneous gabbroic xenoliths, ranging from ~ 1 to 6 cm in dimension, are derived from the lower continental crust. Spinel-peridotite xenoliths equilibrated in the subcontinental lithosphere at depths of 30 to 60 km and temperatures of 965 °C to 1065 °C. These xenoliths do not preserve evidence of extensive metasomatic enrichment as has been inferred for the mantle below the Damavand volcano further to the west in north-central Iran, and clinopyroxenes separated from two different mantle xenoliths have 87Sr/86Sr (0.704309 and 0.704593) and 143Nd/144Nd (0.512798) ratios which are less radiogenic than either their host alkali basalt or Damavand basalts, implying significant regional variations in the composition and extent of

  7. 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.

    Petrographical features of the Central Indian Basin (CIOB) basalts were studied to understand their genetic significance. The fresh basaltic pillows show three textural zones from the top glassy (zone A) through the intermediate (zone B...

  8. Subseafloor basalts as fungal habitats

    Science.gov (United States)

    Ivarsson, M.; Bengtson, S.

    2013-12-01

    The oceanic crust makes up the largest potential habitat for life on Earth, yet next to nothing is known about the abundance, diversity and ecology of its biosphere. Our understanding of the deep biosphere of subseafloor crust is, with a few exceptions, based on a fossil record. Surprisingly, a majority of the fossilized microorganisms have been interpreted or recently re-interpreted as remnants of fungi rather than prokaryotes. Even though this might be due to a bias in fossilization the presence of fungi in these settings can not be neglected. We have examined fossilized microorganisms in drilled basalt samples collected at the Emperor Seamounts in the Pacific Ocean. Synchrotron-radiation X-ray tomography microscopy (SRXTM) studies has revealed a complex morphology and internal structure that corresponds to characteristic fungal morphology. Chitin was detected in the fossilized hyphae, which is another strong argument in favour of a fungal interpretation. Chitin is absent in prokaryotes but a substantial constituent in fungal cell walls. The fungal colonies consist of both hyphae and yeast-like growth states as well as resting structures and possible fruit bodies, thus, the fungi exist in vital colonies in subseafloor basalts. The fungi have also been involved in extensive weathering of secondary mineralisations. In terrestrial environments fungi are known as an important geobiological agent that promotes mineral weathering and decomposition of organic matter, and they occur in vital symbiosis with other microorganisms. It is probable to assume that fungi would play a similar role in subseafloor basalts and have great impact on the ecology and on biogeochemical cycles in such environments.

  9. 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.

  10. Simulating the structure of gypsum composites using pulverized basalt waste

    Directory of Open Access Journals (Sweden)

    Buryanov Аleksandr

    2017-01-01

    Full Text Available This paper examines the possibility of simulating the structure of gypsum composite modified with basalt dust waste to make materials and products based on it. Structural simulating of the topological space in gypsum modified composite by optimizing its grain-size composition highly improves its physical and mechanical properties. Strength and density tests have confirmed the results of the simulation. The properties of modified gypsum materials are improved by obtaining of denser particle packing in the presence of hemihydrate of finely dispersed basalt and plasticizer particles in the system, and by engaging basalt waste in the structuring process of modified gypsum stone.

  11. 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.

  12. Basalt alteration and basalt-waste interaction in the Pasco Basin of Washington State. Final report

    International Nuclear Information System (INIS)

    Benson, L.V.; Carnahan, C.L.; Apps, J.A.; Mouton, C.A.; Corrigan, D.J.; Frisch, C.J.; Shomura, L.K.

    1978-09-01

    A study was conducted to determine the nature of the minerals which coat vesicle and fracture surfaces in the Grande Ronde Basalt Formation, simulate the mass transfer which led to their precipitation, and predict the mass transfer associated with the dissolution of spent unreprocessed fuel (SURF). Scanning electron microscopy (SEM), petrographic, x-ray diffraction (XRD), and electron microprobe (EMP) analyses have been made on a series of samples taken from 1100 ft (335.3 m) of core from core hole DC2. Preliminary simulations of the mass transfer associated with basalt dissolution in a thermodynamically closed system have been accomplished. In addition two mass transfer codes have been modified to facilitate data base changes. Thermochemical data for uranium and plutonium have been collected and converted to standard state conditions. These data will be critically evaluated and input to the mass transfer data base in the near future

  13. Behavior of 99Tc in doped-glass/basalt hydrothermal interaction tests

    International Nuclear Information System (INIS)

    Coles, D.G.; Apted, M.J.

    1984-01-01

    The release of polyvalent radionuclides from a nuclear waste repository located in basalt may be sensitively related to the redox potential (Eh) imposed by the basalt. A series of tests are reported here, evaluating the effect of basalt on the concentrations of 99 Tc released into solution from a borosilicate glass waste form. Crushed PNL 76-68 glass, doped with 0.7 mg 99 Tc/g glass, was reacted with reference basalt groundwater under oxic hydrothermal conditions in a sampling autoclave, both alone and in the presence of crushed basalt. The steady state fluid concentrations of 99 Tc and various table species were determined from samples obtained at the test conditions of 200 0 C, 30 MPa, and a initial solution to solid mass ratio of 10 for both tests. In the glass + groundwater test, the 99 Tc concentration rose rapidly to about 50 mg/L after only 200 hr of run time and remained at a value between 50 and 60 mg/L throughout the duration of the test. For the basalt + glass + groundwater test, the 99 Tc concentration rose to an initial value of about 2.5 mg/L. At about 700 hr, the 99 Tc concentration began to drop rapidly until a value near the analytical detection limit (approximately 0.005 mg/L) was reached after a test duration of 1400 hr. It is concluded that the presence of basalt in these hydrothermal experiments reduces the concentration of 99 Tc in solution by nearly four orders of magnitude, probably by control of solution Eh and subsequent precipitation of a solid containing a reduced form of technetium. Reaction mechanisms are discussed that can account for these observations. 17 references, 1 figure

  14. Back-arc basalts from the Loncopue graben (Province of Neuquen, Argentina)

    Science.gov (United States)

    Varekamp, J. C.; Hesse, A.; Mandeville, C. W.

    2010-11-01

    Young basaltic back-arc volcanoes occur east of the main Andes chain at about 37.5°-39°S in the Loncopue graben, Province of Neuquen, Argentina. These olivine-rich basalts and trachybasalts have up to 8% MgO, with high Ni and Cr contents, but highly variable incompatible element concentrations. Mafic lava flows and cinder cones at the southern end of the graben lack phenocrystic plagioclase. The northern samples have relative Ta-Nb depletions and K, Pb and LREE enrichment. These samples strongly resemble rocks of the nearby arc volcanoes Copahue and Caviahue, including their Fe-Ti enrichment relative to the main Andes arc rocks. The Sr, Nd and Pb isotope ratios show that the source regions of these back-arc basalts are enriched in subducted components that were depleted in the aqueous mobile elements such as Cs, Sr and Ba as a result of prior extractions from the subducted complex below the main arc. Some mafic flows show slightly low 206Pb/ 204Pb and 143Nd/ 144Nd values as well as incompatible trace element ratios similar to southern Patagonia plateau back-arc basalts, suggesting contributions from an EM1 mantle source. Geothermometry and barometry suggest that the basalts crystallized and fractionated small amounts of olivine and spinel at ˜ 35 km depth at temperatures of 1170-1220 °C, at about QFM + 0.5 to QFM + 1 with 1-2% H 2O, and then rose rapidly to the surface. The Loncopue graben back-arc basalts are transitional in composition between the South Patagonia back-arc plateau basalts and the Caviahue and Copahue arc volcanoes to the northwest. The EM1 source endmember is possibly the subcontinental lithospheric mantle. Strong variations in incompatible element enrichment and isotopic compositions between closely spaced cinder cones and lava flows suggest a heterogeneous mantle source for the Loncopue graben volcanics.

  15. Testing Predictions of Continental Insulation using Oceanic Crustal Thicknesses

    Science.gov (United States)

    Hoggard, Mark; Shorttle, Oliver; White, Nicky

    2016-04-01

    The thermal blanketing effect of continental crust has been predicted to lead to elevated temperatures within the upper mantle beneath supercontinents. Initial break-up is associated with increased magmatism and the generation of flood basalts. Continued rifting and sea-floor spreading lead to a steady reduction of this thermal anomaly. Recently, evidence in support of this behaviour has come from the major element geochemistry of mid-ocean ridge basalts, which suggest excess rifting temperatures of ˜ 150 °C that decay over ˜ 100 Ma. We have collated a global inventory of ˜ 1000 seismic reflection profiles and ˜ 500 wide-angle refraction experiments from the oceanic realm. Data are predominantly located along passive margins, but there are also multiple surveys in the centres of the major oceanic basins. Oceanic crustal thickness has been mapped, taking care to avoid areas of secondary magmatic thickening near seamounts or later thinning such as across transform faults. These crustal thicknesses are a proxy for mantle potential temperature at the time of melt formation beneath a mid-ocean ridge system, allowing us to quantify the amplitude and duration of thermal anomalies generated beneath supercontinents. The Jurassic break-up of the Central Atlantic and the Cretaceous rifting that formed the South Atlantic Ocean are both associated with excess temperatures of ˜ 50 °C that have e-folding times of ˜ 50 Ma. In addition to this background trend, excess temperatures reach > 150 °C around the region of the Rio Grande Rise, associated with the present-day Tristan hotspot. The e-folding time of this more local event is ˜ 10 Ma, which mirrors results obtained for the North Atlantic Ocean south of Iceland. In contrast, crustal thicknesses from the Pacific Ocean reveal approximately constant potential temperature through time. This observation is in agreement with predictions, as the western Pacific was formed by rifting of an oceanic plate. In summary

  16. Properties of composite laminates based on basalt fibers with epoxidized vegetable oils

    International Nuclear Information System (INIS)

    Samper, M.D.; Petrucci, R.; Sanchez-Nacher, L.; Balart, R.; Kenny, J.M.

    2015-01-01

    Highlights: • New environmentally friendly composites from biobased epoxies and basalt fibers. • Improved performance with conventional silane treatment on basalt fabrics. • Composites with excellent appearance due to basalt shiny brown color. • Potential applications as substitute of glass fiber reinforced composites in engineering design. • Processing with conventional resin transfer molding (RTM) techniques. - Abstract: This paper deals with the development of polymeric materials derived from epoxidized vegetable oils which have been used in the manufacture of laminated composite materials with basalt fabrics. Epoxidized linseed oil (ELO) and epoxidized soybean oil (ESBO) were used as biobased matrices. The basalt fabrics were modified with amino-silane and glycidyl-silane to increase fiber–matrix interactions. The curing behavior of both resins was evaluated by differential scanning calorimetry (DSC) and oscillatory rheometry (OR). The evaluation of mechanical properties was made by tensile, flexural and Charpy tests. The extent of the fiber–matrix interactions among interface was evaluated by scanning electron microscopy (SEM). The obtained results revealed that surface modification of basalt fibers with glycidyl-silane clearly improves the mechanical properties of the composites. The use of the ELO resin as matrix for composite laminates improved substantially the mechanical performance compared to composites made with ESBO

  17. 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

  18. 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.

  19. 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

  20. Use of solar power for the production of basalt-based mineral fibers

    International Nuclear Information System (INIS)

    Gulamova, D. D.; Shevchenko, V. P.; Tokunov, S. G.; Kim, R. B.

    2012-01-01

    The possibility of obtaining basalt mineral fibers using concentrating solar power and melt-quench technique is shown. The microstructure and physicochemical properties of basalt fibers are analyzed. (author)

  1. 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.

  2. 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.

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

    Science.gov (United States)

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

    2012-01-01

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

  4. 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.

  5. 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

  6. La Isla de Gorgona, Colombia: A petrological enigma?

    Science.gov (United States)

    Kerr, Andrew C.

    2005-09-01

    A wide range of intrusive (wehrlite, dunite, gabbro and olivine gabbro) and extrusive (komatiites picrites and basalts) igneous rocks are found on the small pacific island of Gorgona. The island is best known for its ˜90 Ma spinifex-textured komatiites: the only true Phanerozoic komatiites yet discovered. Early work led to suggestions that the rocks of the island formed at a mid-ocean ridge, however more recent research supports an origin as part of a hot mantle plume-derived oceanic plateau. One of the main lines of evidence for this origin stems from the inferred high mantle source temperatures required to form the high-MgO (> 15 wt.%) komatiites and picrites. Another remarkable feature of the island, considering its small size (8 × 2.5 km), is the degree of chemical and radiogenic isotopic heterogeneity shown by the rocks. This heterogeneity requires a mantle source region with at least three isotopically distinctive source regions (two depleted and one enriched). Although these mantle source regions appear to be derived in significant part from recycled oceanic crust and lithosphere, enrichments in 187Os, 186Os and 3He in Gorgona lavas and intrusive rocks, suggest some degree of transfer of material from the outer core to the plume source region at D″. Modelling reveals that the komatiites probably formed by dynamic melting at an average pressure of 3-4 GPa leaving residual harzburgite. Trace element depletion in Gorgona ultramafic rocks appears to be the result of earlier, deeper melting which produced high-MgO trace element-enriched magmas. The discovery of a trace-element enriched picrite on the island has confirmed this model. Gorgona accreted onto the palaeocontinental margin of northwestern South America in the Eocene and palaeomagnetic work reveals that it was formed at ˜26 °S. It has been proposed that Gorgona is a part of the Caribbean-Colombian Oceanic Plateau (CCOP), however, the CCOP accreted in the Late Cretaceous and was derived from a more

  7. Regional basalt hydrology of the Columbia Plateau in Washington

    International Nuclear Information System (INIS)

    Tanaka, H.; Barrett, G.; Wildrick, L.

    1979-10-01

    This study is part of the Basalt Waste Isolation Project, operated for the US Department of Energy by Rockwell Hanford Operations. The overall purpose of the study is to assess locations within the Columbia River Basalt Group beneath the Hanford Site in south-central Washington suitable for a geologic repository for radioactive waste. This hydrologic study was made to describe the hydrologic characteristics of the basalt units of the Columbia Plateau. This was done by comprehensive data compilation, data interpretation and analysis. Data are presented in the form of maps and tables suitable as input information about the regional hydrology for possible future analysis by computer models. The report includes: an introduction; basic data; interpretation which covers stratigraphic trend surface, water levels, transmissivity and storage of aquifers, recharge, discharge, flow, subbasins, cross sections, references and appendix of record of wells

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Copuroglu, Oguzhan, E-mail: O.Copuroglu@CiTG.TUDelft.NL [Delft University of Technology, Faculty of CiTG, Materials and Environment, Stevinweg 1, 2628CN, Delft (Netherlands); Andic-Cakir, Ozge [Ege University, Civil Engineering Dept., 35100 Bornova, Izmir (Turkey); Broekmans, Maarten A.T.M. [Geological Survey of Norway, Dept. of Mineral Characterization, N-7491 Trondheim (Norway); Kuehnel, Radko [Burgemeester Merkusstraat 5, 2645 NJ, Delfgauw (Netherlands)

    2009-07-15

    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{sub 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.

  10. Friction Joint Between Basalt-Reinforced Composite and Aluminum

    DEFF Research Database (Denmark)

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

    2015-01-01

    The purpose of this study was to anchor basalt-reinforced polymers in an aluminum grip using dry friction. Dry friction clamping is considered the optimal solution for post-mounting of load-bearing terminations on composite structures. A new test method is presented for characterizing the frictio......The purpose of this study was to anchor basalt-reinforced polymers in an aluminum grip using dry friction. Dry friction clamping is considered the optimal solution for post-mounting of load-bearing terminations on composite structures. A new test method is presented for characterizing...

  11. Hydrologic test results for the Rattlesnake Ridge interbed and Pomona basalt flow top at Borehole DB-15

    International Nuclear Information System (INIS)

    Strait, S.R.; Brown, W.R.

    1983-07-01

    This report presents results and description of hydrologic test activities for the Rattlesnake Ridge interbed and Pomona basalt flow top at Borehole DB-15. Hydrologic tests conducted include constant discharge air-lift and constant discharge submersible pumping tests. An observed hydraulic head for the test interval was 409 ± 1 feet above mean sea level. Transmissivity values determined from hydrologic tests performed, ranged between 493 and 469 ft 2 /day. The best estimate of transmissivity is 480 ft 2 /day. The best estimate of equivalent hydraulic conductivity, based on an effective test thickness of 56 feet is 8.6 ft/day. 4 refs., 7 figs., 2 tabs

  12. Chemical differences between small subsamples of Apollo 15 olivine-normative basalts

    Science.gov (United States)

    Shervais, J. W.; Vetter, S. K.; Lindstrom, M. M.

    1990-01-01

    Results are presented on the chemical and petrological characterization of nine samples of an Apollo 15 mare basalt suite. The results show that all nine samples are low-silica olivine normative basalts (ONBs) similar to those described earlier for low-silica ONBs from Apollo 15 site. The samples were found to vary in texture and grain size, from fine-grained intergranular or subophitic basalts to coarse-grained granular 'microgabbros'. Several displayed macroscopic heterogeneity. Variation diagrams show that the overall trend of the data is consistent with the fractionation of olivine (plus minor Cr-spinel) from a high-MgO parent magma.

  13. Experimental Study on Unconfined Compressive Strength of Basalt Fiber Reinforced Clay Soil

    Directory of Open Access Journals (Sweden)

    Lei Gao

    2015-01-01

    Full Text Available In order to study the mechanism and effect of basalt fiber reinforced clay soil, a series of unconfined compressive strength tests conducted on clay soil reinforced with basalt fiber have been performed under the condition of optimum water content and maximum dry density. Both the content and length of basalt fiber are considered in this paper. When the effect of content is studied, the 12 mm long fibers are dispersed into clay soil at different contents of 0.05%, 0.1%, 0.15%, 0.20%, 0.25%, 0.30%, and 0.35%. When the effect of length is researched, different lengths of basalt fibers with 4 mm, 8 mm, 12 mm, and 15 mm are put into soil at the same content of 0.05%. Experimental results show that basalt fiber can effectively improve the UCS of clay soil. And the best content and length are 0.25% and 12 mm, respectively. The results also show that the basalt fiber reinforced clay soil has the “poststrong” characteristic. About the reinforcement mechanism, the fiber and soil column-net model is proposed in this paper. Based on this model and SEM images, the effect of fiber content and length is related to the change of fiber-soil column and formation of effective fiber-soil net.

  14. 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.

  15. Autogenous Tumbling Media Assessment to Clean Weathered Surfaces of Waste-Rock Particles from a Basalt Quarry

    Directory of Open Access Journals (Sweden)

    Baran Tufan

    2015-06-01

    Full Text Available In this study, the optimum feed composition in autogenous tumbling of basalt waste-rock particles to clean their weathered surface was determined. The weathered surfaces of basalt are generally cut out consequent to extraction of basalt columns in quarry operations. The inefficiently cut out portions of basalt cause formation of huge quarry waste dumps causing visual pollution on roadsides. Mixtures of different particle size fractions of basalt waste-rock particles were experimented to achieve the optimum feed material composition. The minimum loss of commercially available basalt particles and maximum clear surface was intended. The results were compared with respect to weight loss (% and reflectance values of used and generated samples.

  16. Basalt woven fiber reinforced vinylester composites: Flexural and electrical properties

    International Nuclear Information System (INIS)

    Carmisciano, Salvatore; Rosa, Igor Maria De; Sarasini, Fabrizio; Tamburrano, Alessio; Valente, Marco

    2011-01-01

    A preliminary comparative study of basalt and E-glass woven fabric reinforced composites was performed. The fabrics were characterized by the same weave pattern and the laminates tested by the same fiber volume fraction. Results of the flexural and interlaminar characterization are reported. Basalt fiber composites showed higher flexural modulus and apparent interlaminar shear strength (ILSS) in comparison with E-glass ones but also a lower flexural strength and similar electrical properties. With this fiber volume fraction, scanning electron microscopy (SEM) analysis of the fractured surfaces enabled a better understanding both of the failure modes involved and of points of concern. Nevertheless, the results of this study seem promising in view of a full exploitation of basalt fibers as reinforcement in polymer matrix composites (PMCs).

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

    Science.gov (United States)

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

    2010-01-01

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

  18. Using ESEM to analyze the microscopic property of basalt fiber reinforced asphalt concrete

    Directory of Open Access Journals (Sweden)

    Chunmei Gao

    2018-07-01

    Full Text Available The basalt fiber staggered distribution in the asphalt concrete matrix and the bonding situation between asphalt are analyzed by images collected using field emission environmental scanning electron microscope (ESEM test equipment. The results show that bonding of the fiber and the asphalt binder is very good and there is a strong binding force of chemical bonding connections between the two; the lipophilicity of basalt fiber is very good, the wrapped cover ability of asphalt for fiber is very strong; basalt fiber forms the local space network structure in the asphalt concrete matrix, effectively overcome the relative slip between the particles, connect the damaged parts into a whole; basalt fiber across internal micropores, and the internal defects in material can be remedied. At the same time, crack resistance mechanism of the fiber to internal micro cracks is qualitatively explained according to the magnitude of the stress intensity factor Kf. Keywords: Road engineering, Asphalt concrete, Basalt fiber, Microscopic analysis

  19. Single and Multi-Date Landsat Classifications of Basalt to Support Soil Survey Efforts

    Directory of Open Access Journals (Sweden)

    Jessica J. Mitchell

    2013-10-01

    Full Text Available Basalt outcrops are significant features in the Western United States and consistently present challenges to Natural Resources Conservation Service (NRCS soil mapping efforts. Current soil survey methods to estimate basalt outcrops involve field transects and are impractical for mapping regionally extensive areas. The purpose of this research was to investigate remote sensing methods to effectively determine the presence of basalt rock outcrops. Five Landsat 5 TM scenes (path 39, row 29 over the year 2007 growing season were processed and analyzed to detect and quantify basalt outcrops across the Clark Area Soil Survey, ID, USA (4,570 km2. The Robust Classification Method (RCM using the Spectral Angle Mapper (SAM method and Random Forest (RF classifications was applied to individual scenes and to a multitemporal stack of the five images. The highest performing RCM basalt classification was obtained using the 18 July scene, which yielded an overall accuracy of 60.45%. The RF classifications applied to the same datasets yielded slightly better overall classification rates when using the multitemporal stack (72.35% than when using the 18 July scene (71.13% and the same rate of successfully predicting basalt (61.76% using out-of-bag sampling. For optimal RCM and RF classifications, uncertainty tended to be lowest in irrigated areas; however, the RCM uncertainty map included more extensive areas of low uncertainty that also encompassed forested hillslopes and riparian areas. RCM uncertainty was sensitive to the influence of bright soil reflectance, while RF uncertainty was sensitive to the influence of shadows. Quantification of basalt requires continued investigation to reduce the influence of vegetation, lichen and loess on basalt detection. With further development, remote sensing tools have the potential to support soil survey mapping of lava fields covering expansive areas in the Western United States and other regions of the world with similar

  20. Rock mass deformation properties of closely jointed basalt

    International Nuclear Information System (INIS)

    Kim, K.; Cramer, M.L.

    1982-12-01

    The deformational behavior of the Columbia River basalt is being investigated as part of a comprehensive site characterization program intended to determine the feasibility of constructing a nuclear waste repository in basalt at Hanford, Washington. Direct field measurements were conducted in a 2-m cube of basalt to obtain truly representative rock mass deformation properties. Load was applied to the test block in three orthogonal directions through the use of flat jacks in two perpendicular planes and a cable anchor system in the third. This configuration allowed the block to be placed in a simulated triaxial stress state at stress levels up to 12.5 MPa. The deformation at the center of the test block was monitored through the use of an optical measurement system developed for this project. The results indicate that the vertically oriented columnar joints have a significant influence on the deformation behavior of the basalt. The modulus in the direction parallel to the column axis was approx. 30 GPa, while the modulus value perpendicular to the columns was approx. 20 GPa. Laboratory measurements of intact specimens taken from this area yielded a value of 80 GPa with no indication of anisotropy. Hysteresis was observed in all loading cycles, but was distinctly more pronounced perpendicular to the column axis, indicative of significant joint displacement in this direction. The results of this test represent the first true rock mass modulus data obtained in closely jointed rock on a large scale. These measurement methods have eliminated many of the ambiguities associated with borehole jacking and surface measurement techniques

  1. 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

  2. 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)

  3. Geochemistry of cenozoic basaltic rocks from Shandong province and its implication for mantle process in North China

    International Nuclear Information System (INIS)

    Lee Yungtan; Chen Juchin; Huang Shaowei; Shih Jyhyi; Lin Menglung; Juang Wenshing; Yang Huaijen

    2006-01-01

    Cenozoic (Miocene to Pleistocene) basaltic rocks found in Shandong province of northern China include tholeiite, olivine tholeiite and alkali basalt. We present major, trace and rare earth elements data of these basalts and together with Sr-Nd isotopic data in the literatures to discuss the petrogenesis of these basalts. The basalts from Penglai area have higher K, Na and P and incompatible elements, but lower Ca, Mg and compatible elements contents than those from Changle area of Shandong province. Spidergrams indicate that Cenozoic basalts from Shandong province have geochemical characteristics similar to those of ocean island basalts (OIB) with slight positive Nb anomaly. The negative Ba, Rb and K anomalies found in the alkali basalts suggest the presence of residual phlogopite in the mantle source, indicating a metasomatic event occurred before the partial melting. The 143 Nd/ 144 Nd vs. 87 Sr/ 86 Sr plot suggested that basalts from Shandong province can be produced by MORB and EM-I components mixing. We propose that the EM-I type lithospheric mantle may have been produced by the recent H 2 O-CO 2 -fluids metasomatism and the fluids may be derived from dehydration of the subducted slab. Based on Shaw's equation, the basalts from eastern and central Shandong province have undergone different degrees of particle melting from the mantle source. Degrees of partial melting and chemical composition of basalts from Shandong province suggest that the lithosphere has thickened progressively since the Miocene. On the basis of Ar-Ar ages of this study and the fractional crystallization model proposed by Brooks and Nielsen (1982), we suggest that basalts from Changle and Penglai areas belong to different magmatic systems which have undergone fractional crystallization and evolved progressively to produce other types of basalts. (author)

  4. 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

  5. The durability of fired brick incorporating textile factory waste ash and basaltic pumice

    Energy Technology Data Exchange (ETDEWEB)

    Binici, Hanifi [Kahramanmaras Sutcu Imam Univ., Kahramanmaras (Turkey). Dept. of Civil Engineering; Yardim, Yavuz [Epoka Univ., Tirana (Albania). Dept. of Civil Engineering

    2012-07-15

    This study investigates the durability of fired brick produced with additives of textile factories' waste ash and basaltic pumice. The effects of incorporating waste ash and basaltic pumice on durability and mechanical properties of the clay bricks were studied. Samples were produced with different ratios of the textile factories' waste ash and basaltic pumice added and at different fire temperatures of 700, 900, and 1 050 C for 8 h. The bricks with additives were produced by adding equal amounts of textile factories' waste ash and basaltic pumice, separately and together, with rates of 5, 10 and 20 wt.%. The produced samples were kept one year in sodium sulphate and sodium nitrate and tested under freezing - unfreezing and drying - wetting conditions. Then compression strength and mass loss of the samples with and without additives were investigated. The test results were compared with standards and results obtained from control specimens. The results showed that incorporations up to 10 wt.% of textile factories' waste ash and basaltic pumice is beneficial to the fired brick. Both textile factories' waste ash and basaltic pumice were suitable additives and could be used for more durable clay brick production at 900 C fire temperature. (orig.)

  6. Degradation of basalt fibre and glass fibre/epoxy resin composites in seawater

    International Nuclear Information System (INIS)

    Wei Bin; Cao Hailin; Song Shenhua

    2011-01-01

    Research highlights: → BFRP degradation process in seawater environment was first investigated. → The mass gain change includes two effects: absorption and extraction. → The interfacial adhesion of BFRP is bigger than GFRP. → After treated, the bending strength of BFRP is lower than GFRP. → Reducing the Fe 2+ in the basalt fibre could lead to a higher stability of BFRP. - Abstract: Epoxy resins reinforced, respectively, by basalt fibres and glass fibres were treated with a seawater solution for different periods of time. Both the mass gain ratio and the strength maintenance ratio of the composites were examined after the treatment. The fracture surfaces were characterized using scanning electron microscopy. The tensile and bending strengths of the seawater treated samples showed a decreasing trend with treating time. In general, the anti-seawater corrosion property of the basalt fibre reinforced composites was almost the same as that of the glass fibre reinforced ones. Based on the experimental results, possible corrosion mechanisms were explored, indicating that an effective lowering of the Fe 2+ content in the basalt fibre could lead to a higher stability for the basalt fibre reinforced composites in a seawater environment.

  7. Re-Os isotope systematics of the Radio Hill Ni-Cu-PGE complex, West Pilbara Craton, Western Australia

    International Nuclear Information System (INIS)

    Frick, L.R.; McBride, J.S.

    1999-01-01

    Full text: The Radio Hill Complex is one of several layered mafic-ultramafic intrusions that were emplaced into the west Pilbara Craton at ca. 2.9 Ga. It is believed to be genetically related to other similar intrusions in the area which include the Munni Munni, Andover, Dingo and Maitland Complexes (Hoatson et al. 1999). The Radio Hill Complex is the only one of these intrusions to contain economic quantities of Ni and Cu at the present time. This relatively small intrusion (∼1200 m stratigraphic thickness) is divided into two zones, an upper gabbroic zone and a lower ultramafic zone, the base of which possesses massive magmatic sulfide mineralisation (pyrrhotite, pentlandite, chalcopyrite, magnetite). Re-Os isotopic data have been obtained for a suite of samples from underground, outcrop (gabbroic zone samples) and drill core. Os concentrations in the mineralised zone are very high, ranging from 19 to 191 ppb Os, with low Re/Os ratios ( 10,000), where R-factor is defined as the mass ratio of silicate magma to sulfide magma that it has equilibrated with. However, modelling of the Radio Hill ore system using Re, Os and PGE (Hoatson et al. 1992) concentrations suggest that the R-factor in the Radio Hill ore was low (100-900). Therefore, the initial Os isotopic composition of the ore should be radiogenic (high gOs >+500) if local crustal contamination triggered sulfide saturation. The slightly radiogenic initial Os isotopic composition suggests that the bulk parental magma was a crustally-contaminated magma. R-factor modelling further suggests that the parental magma to this intrusion was neither a basalt nor a pure komatiite, but more likely a contaminated komatiite (with a relatively high Os concentration). This agrees with the previous findings of Hoatson et al. (1992) who proposed a parental magma of siliceous high-magnesium basalt (SHMB) composition. Our Re-Os isotope modelling agrees with the trace elements, Nd and Sr isotope modelling of Hoatson et al. (1992

  8. Selective environmental stress from sulphur emitted by continental flood basalt eruptions

    Science.gov (United States)

    Schmidt, Anja; Skeffington, Richard; Thordarson, Thorvaldur; Self, Stephen; Forster, Piers; Rap, Alexandru; Ridgwell, Andy; Fowler, David; Wilson, Marjorie; Mann, Graham; Wignall, Paul; Carslaw, Ken

    2016-04-01

    Several biotic crises during the past 300 million years have been linked to episodes of continental flood basalt volcanism, and in particular to the release of massive quantities of magmatic sulphur gas species. Flood basalt provinces were typically formed by numerous individual eruptions, each lasting years to decades. However, the environmental impact of these eruptions may have been limited by the occurrence of quiescent periods that lasted hundreds to thousands of years. Here we use a global aerosol model to quantify the sulphur-induced environmental effects of individual, decade-long flood basalt eruptions representative of the Columbia River Basalt Group, 16.5-14.5 million years ago, and the Deccan Traps, 65 million years ago. For a decade-long eruption of Deccan scale, we calculate a decadal-mean reduction in global surface temperature of 4.5 K, which would recover within 50 years after an eruption ceased unless climate feedbacks were very different in deep-time climates. Acid mists and fogs could have caused immediate damage to vegetation in some regions, but acid-sensitive land and marine ecosystems were well-buffered against volcanic sulphur deposition effects even during century-long eruptions. We conclude that magmatic sulphur from flood basalt eruptions would have caused a biotic crisis only if eruption frequencies and lava discharge rates had been high and sustained for several centuries at a time.

  9. Experimental Study on Unconfined Compressive Strength of Basalt Fiber Reinforced Clay Soil

    OpenAIRE

    Gao, Lei; Hu, Guohui; Xu, Nan; Fu, Junyi; Xiang, Chao; Yang, Chen

    2015-01-01

    In order to study the mechanism and effect of basalt fiber reinforced clay soil, a series of unconfined compressive strength tests conducted on clay soil reinforced with basalt fiber have been performed under the condition of optimum water content and maximum dry density. Both the content and length of basalt fiber are considered in this paper. When the effect of content is studied, the 12 mm long fibers are dispersed into clay soil at different contents of 0.05%, 0.1%, 0.15%, 0.20%, 0.25%, 0...

  10. Effect of basalt, silica sand and fly ash on the mechanical properties ...

    Indian Academy of Sciences (India)

    2018-05-17

    May 17, 2018 ... For this, we first manufactured binary PCs of epoxy/basalt ... Keywords. Polymer concrete; mechanical strength; mixture design; fly ash; silica sand; basalt. 1. .... To reduce the production cost of PCs, it is necessary to minimize ...

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-05-23

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

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

    International Nuclear Information System (INIS)

    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

  14. Elevation of surficial sediment/basalt contact in the Subsurface Disposal Area, Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Hubbell, J.M.

    1993-01-01

    The elevation of the surficial sediment/basalt contact at the Subsurface Disposal Area (SDA), within the Radioactive Waste Management Complex (RWMC) is presented to provide a data base for future remedial actions at this site. About 1,300 elevation data from published and unpublished reports, maps, and surveyors notes were compiled to generate maps and cross-sections of the surficial sediment/basalt contact. In general, an east to west trending depression exists in the south central portion of the SDA with basalt closer to land surface on the northern and southern boundaries of the SDA. The lowest elevation of the surficial sediment/basalt contact is 4,979 ft and the greatest is land surface at 5,012 ft. The median elevation of the sediment/basalt interface is 4,994 ft. The median depth to basalt in the SDA is 16 ft if land surface elevation is assumed to be 5,010 ft. The depth from land surface to the sediment/basalt interface ranges from 24 ft in the southeast corner of the SDA to less than 3 ft at the north-central boundary of the SDA

  15. Prokaryotic diversity, distribution, and insights into their role in biogeochemical cycling in marine basalts and gabbros

    Science.gov (United States)

    Mason, O. U.; di Meo-Savoie, C. A.; Nakagawa, T.; van Nostrand, J. D.; Rosner, M.; Maruyama, A.; Zhou, J.; Fisk, M. R.; Giovannoni, S. J.

    2008-12-01

    Oceanic crust covers nearly 70% of the Earth's surface, of which, the upper, sediment layer is estimated to harbor substantial microbial biomass. Marine crust, however, extends several kilometers beyond this surficial layer, and includes the basalt and gabbro layers. The microbial diversity in basalts is well characterized, yet metabolic diversity is unknown. To date, the microflora associated with gabbros, including microbial and metabolic diversity has not been reported. In our analyses basaltic and gabbroic endoliths were analyzed using terminal restriction fragment length polymorphism, cloning and sequencing, and microarray analysis of functional genes. Our results suggest that despite nearly identical chemical compositions of basalt and gabbro the associated microflora did not overlap. Basalt samples harbor a surprising diversity of seemingly cosmopolitan microorganisms, some of which appear to be basalt specialists. Conversely, gabbros have a low diversity of endoliths, none of which appear to be specifically adapted to the gabbroic environment. Microarray analysis (GeoChip) was used to assay for functional gene diversity in basalts and gabbros. In basalt genes coding for previously unreported processes such as carbon fixation, methane-oxidation, methanogenesis, and nitrogen fixation were present, suggesting that basalts harbor previously unrecognized metabolic diversity. Similar processes were observed in gabbroic samples, yet metabolic inference from phylogenetic relationships of gabbroic endoliths with other microorganisms, suggests that hydrocarbon oxidation is the prevailing metabolism in this environment. Our analyses revealed that the basalt and gabbro layers harbor microorganisms with the genetic potential to significantly impact biogeochemical cycling in the lithosphere and overlying hydrosphere.

  16. Petrology of dune sand derived from basalt on the Ka'u Desert, Hawaii

    Science.gov (United States)

    Gooding, J. L.

    1982-01-01

    Dune sand from the Ka'u Desert, southwest flank of Kilauea volcano, Hawaii, is moderately well-sorted (median = 1.60 Phi, deviation = 0.60, skewness = 0.25, kurtosis = 0.68) and composed mostly of frosted subangular particles of basalt glass ('unfractionated' olivine-normative tholeitte), olivine, lithic fragments (subophitic and intersertal basalts; magnetite-ilmenite-rich basalts), reticular basalt glass, magnetite, ilmenite, and plagioclase, in approximately that order of abundance. Quantitative lithological comparison of the dune sand with sand-sized ash from the Keanakakoi Formation supports suggestions that the dune sand was derived largely from Keanakakoi ash. The dune sand is too well sorted to have been emplaced in its present form by base-surge but could have evolved by post-eruption reworking of the ash.

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

    Directory of Open Access Journals (Sweden)

    Guojun LU

    2014-12-01

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

  18. 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.

  19. 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

  20. 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)

  1. Heat resistance study of basalt fiber material via mechanical tests

    Science.gov (United States)

    Gao, Y. Q.; Jia, C.; Meng, L.; Li, X. H.

    2017-12-01

    This paper focuses on the study of the relationship between the fracture strength of basalt rovings and temperature. Strong stretching performance of the rovings has been tested after the treatment at fixed temperatures but different heating time and then the fracture strength of the rovings exposed to the heating at different temperatures and cooled in different modes investigated. Finally, the fracture strength of the basalt material after the heat treatment was studied. The results showed that the room-temperature strength tends to decrease with an increase of the heat treatment time at 250 °C, but it has the local maximum after 2h heating. And the basalt rovings strength increased after the heat treatment up to 200 °C. It was 16.7 percent higher than the original strength. The strength depends not only on the temperature and duration of the heating, but also on the cooling mode. The value of the strength measured after cold water cooling was less by 6.3% compared with an ambient air cooling mode. The room-temperature breaking strength of the rovings heated at 200 °C and 100 °C for 2 hours each increased by about 14.6% with respect to unpretreated basalt rovings.

  2. 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

  3. Seeking a paleontological signature for mass extinctions caused by flood basalt eruptions

    Science.gov (United States)

    Payne, J.; Bush, A. M.; Chang, E. T.; Heim, N. A.; Knope, M. L.; Pruss, S. B.

    2016-12-01

    Flood basalt eruptions coincide with numerous extinction events in the fossil record. Increasingly precise absolute age determinations for both the timing of eruption and of species extinctions have strengthened the case for flood basalt eruptions as the single most important trigger for major mass extinction events in the fossil record. However, the extent to which flood basalt eruptions cause a pattern of biotic loss distinctive from extinctions triggered by other geological or biological processes remains an open question. In the absence of diagnostic mapping between geological triggers and biological losses, establishing the identities of causal agents for mass extinctions will continue to depend primarily on evidence for temporal coincidence. Here we use a synoptic database of marine animal genera spanning the Phanerozoic, including times of first and last occurrence, body size, motility, life position, feeding mode, and respiratory physiology to assess whether extinction events temporally associated with flood basalt eruptions exhibit a diagnostic pattern of extinction selectivity. We further ask whether any events not associated with known large igneous provinces nevertheless display extinction patterns suggestive of such a cause. Finally, we ask whether extinction events associated with other primary causes, such as glaciation or bolide impact, are distinguishable from events apparently triggered by flood basalt eruptions on the basis of extinction selectivity patterns

  4. Corrosion and tribological properties of basalt fiber reinforced composite materials

    Science.gov (United States)

    Ha, Jin Cheol; Kim, Yun-Hae; Lee, Myeong-Hoon; Moon, Kyung-Man; Park, Se-Ho

    2015-03-01

    This experiment has examined the corrosion and tribological properties of basalt fiber reinforced composite materials. There were slight changes of weight after the occurring of corrosion based on time and H2SO4 concentration, but in general, the weight increased. It is assumed that this happens due to the basalt fiber precipitate. Prior to the corrosion, friction-wear behavior showed irregular patterns compared to metallic materials, and when it was compared with the behavior after the corrosion, the coefficient of friction was 2 to 3 times greater. The coefficient of friction of all test specimen ranged from 0.1 to 0.2. Such a result has proven that the basalt fiber, similar to the resin rubber, shows regular patterns regardless of time and H2SO4 concentration because of the space made between resins and reinforced materials.

  5. Preparation of basalt-based glass ceramics

    Directory of Open Access Journals (Sweden)

    MIHOVIL LOGAR

    2003-06-01

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

  6. Commercial nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Hardy, M.P.; Patricio, J.G.; Heley, W.H.

    1980-06-01

    The Basalt Waste Isolation Project (BWIP) is an ongoing research and engineering effort being conducted by Rockwell Hanford Operations (Rockwell), which is under contract to the US Department of Energy. The objectives of this program are to assess the feasibility of and to provide the technology needed to design and construct a licensed commercial nuclear waste repository in the deep basalt formations underlying the Hanford Site. An extensive preconceptual design effort was undertaken during 1979 to develop a feasible concept that could serve as a reference design for both surface and underground facilities. The preconceptual design utilized existing technology to the greatest extent possible to offer a system design that could be utilized in establishing schedule and cost baseline data, recommend alternatives that require additional study, and develop basic design requirements that would allow evolution of the design process prior to the existence of legislated criteria. This paper provides a description of the concept developed for the subsurface aspects of this nuclear waste repository

  7. 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

    by Irvine and Baragar (1971) or MacDonald and. Katsura (1964) were not included here because of the considerable uncertainty that exists in such a classification scheme (see Sheth et al 2002 for more explanation). The Andaman ophiolite samples are mainly basalts (20 samples), with some basaltic andesites.

  8. Basaltic material in the main belt: a tale of two (or more) parent bodies?

    Science.gov (United States)

    Ieva, S.; Dotto, E.; Lazzaro, D.; Fulvio, D.; Perna, D.; Epifani, E. Mazzotta; Medeiros, H.; Fulchignoni, M.

    2018-06-01

    The majority of basaltic objects in the main belt are dynamically connected to Vesta, the largest differentiated asteroid known. Others, due to their current orbital parameters, cannot be easily dynamically linked to Vesta. This is particularly true for all the basaltic asteroids located beyond 2.5 au, where lies the 3:1 mean motion resonance with Jupiter. In order to investigate the presence of other V-type asteroids in the middle and outer main belt (MOVs) we started an observational campaign to spectroscopically characterize in the visible range MOV candidates. We observed 18 basaltic candidates from TNG and ESO - NTT between 2015 and 2016. We derived spectral parameters using the same approach adopted in our recent statistical analysis and we compared our data with orbital parameters to look for possible clusters of MOVs in the main belt, symptomatic for a new basaltic family. Our analysis seemed to point out that MOVs show different spectral parameters respect to other basaltic bodies in the main belt, which could account for a diverse mineralogy than Vesta; moreover, some of them belong to the Eos family, suggesting the possibility of another basaltic progenitor. This could have strong repercussions on the temperature gradient present in the early Solar System, and on our current understanding of differentiation processes.

  9. 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.

  10. 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

  11. Stress Corrosion Cracking of Basalt/Epoxy Composites under Bending Loading

    Science.gov (United States)

    Shokrieh, Mahmood M.; Memar, Mahdi

    2010-04-01

    The purpose of this research is to study the stress corrosion behavior of basalt/epoxy composites under bending loading and submerged in 5% sulfuric acid corrosive medium. There are limited numbers of research in durability of fiber reinforced polymer composites. Moreover, studies on basalt fibers and its composites are very limited. In this research, mechanical property degradation of basalt/epoxy composites under bending loading and submerged in acidic corrosive medium is investigated. Three states of stress, equal to 30%, 50% and 70% of the ultimate strength of composites, are applied on samples. High stress states are applied to the samples to accelerate the testing procedure. Mechanical properties degradation consists of bending strength, bending modulus of elasticity and fracture energy of samples are examined. Also, a normalized strength degradation model for stress corrosion condition is presented. Finally, microscopic images of broken cross sections of samples are examined.

  12. 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...

  13. Feldspar basalts in lunar soil and the nature of the lunar continents

    Science.gov (United States)

    Reid, A. M.; Ridley, W. I.; Harmon, R. S.; Warner, J.; Brett, R.; Jakes, P.; Brown, R. W.

    1974-01-01

    It is found that 25% on the Apollo-14 glasses have the same composition as the glasses in two samples taken from the Luna-16 column. The compositions are equivalent to feldspar basalt and anorthosite gabbro, and are similar to the feldspar basalts identified from Surveyor-7 analysis for lunar continents.

  14. Non-destructive XRF analyses of fine-grained basalts from Eiao, Marquesas Islands

    International Nuclear Information System (INIS)

    Charleux, M.; McAlister, A.; Mills, P.R.; Lundblad, S.P.

    2014-01-01

    The Marquesan island of Eiao was an important source of fine-grained basalt in Central East Polynesia, with examples being identified in archaeological assemblages throughout the region. However, compared to many other large-scale Polynesian basalt sources, little has been published about the physical extent and geochemical variability of tool-quality basalt on Eiao; prior to our study, only a single site with evidence of stone extraction had been identified and geochemical information was limited to less than two dozen samples. In this paper we report geochemical data for 225 additional basalt specimens collected on Eiao. Our analyses were conducted non-destructively using three EDXRF instruments: one lab-based unit and two portable analysers. The majority of our sample, identified here as Group 1, possesses geochemical and physical characteristics similar to those reported in previous studies. Group 1 samples were collected from various locations on Eiao suggesting that, rather than being limited to a single quarry site, fine-grained basalt was extracted from multiple sources throughout the island. In addition, we identified a second group (Group 2), which possesses a distinct geochemistry, a coarser grain and often an unusual reddish colour. Evidence from Eiao indicates that Group 2 stone was regularly utilised and our analysis of an adze collected on Hiva Oa Island suggests that this material was distributed at least as far as the southern Marquesas. (author)

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

    Science.gov (United States)

    Chen, Xi; Li, Yan; Gu, Ning

    2010-08-01

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

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

    International Nuclear Information System (INIS)

    Chen Xi; Li Yan; Gu Ning

    2010-01-01

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

  17. Strontium isotopic and trace element geochemistry of the saddle mountains and Grande Ronde Basalts of the Columbia River Basalt Group

    International Nuclear Information System (INIS)

    Nelson, D.O.

    1980-01-01

    The Columbia River Basalt (CRB) group displays significant variations in major and trace element and Sr isotopic compositions. These compositions reflect complex and variable origins for the CRB magmas. Among the most varied is the Saddle Mountains Basalt (SMB) in which Sr ratios vary from 0.7078 to 0.7147 +- 0.002. The higher ratios reflect contamination through consistent correlations with major element compositions. Modeling suggests contamination by assimilation of 4.4 to 9.4 wt % of radiogenic crustal rocks. High delta 18 O values (up to +7.68 per mil) support the model. Age and field relations suggest that the contamination flowrocks are not the result of progressive contamination of a single magma, but rather reflect the contamination of independent magmas during this ascent

  18. NEW GEOCHEMICAL DATA OF BASALTS IN THE TSOROIDOG AREA, CENTRAL MONGOLIA

    Directory of Open Access Journals (Sweden)

    T. Oyunchimeg

    2017-01-01

    Full Text Available At present, geochemical data are widely used for reconstructing geodynamic settings, especially, volcanic rocks of mafic composition, i.e., basalts, because they are widespread in many orogenic belts and are indicative of different geodynamic environments. In general, we propose the reconstruction of the tectonic settings of basalts according to their relationships with associated ocean plate stratigraphy (OPS sediments, their petrogenesis and their geochemical features.

  19. 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.

  20. Feasibility of storing radioactive wastes in Columbia River basalts

    International Nuclear Information System (INIS)

    Deju, R.A.

    1976-01-01

    In 1968 Atlantic Richfield Hanford Company initiated a study to assess the feasibility of final geologic storage of Hanford defense, radioactive waste in deep caverns constructed in the Columbia River flood basalts. The project, which included geologic studies, hydrologic tests, heat flow analysis, compatibility analysis, and tectonic studies, was suspended in 1972 before completion of interpretive work. In 1976 the interpretation and documentation were completed. These data may be valuable in qualifying the Columbia River flood basalts as a viable medium for final geologic storage of commercial radioactive waste. The findings to date are summarized, and the proposed future work is presented

  1. Mechanical Characterization of Basalt and Glass Fiber Epoxy Composite Tube

    OpenAIRE

    Lapena, Mauro Henrique; Marinucci, Gerson

    2017-01-01

    The application of basalt fibers are possible in many areas thanks to its multiple and good properties. It exhibits excellent resistance to alkalis, similar to glass fiber, at a much lower cost than carbon and aramid fibers. In the present paper, a comparative study on mechanical properties of basalt and E-glass fiber composites was performed. Results of apparent hoop tensile strength test of ring specimens cut from tubes and the interlaminar shear stress (ILSS) test are presented. Tensile te...

  2. Magnetic property zonation in a thick lava flow

    Science.gov (United States)

    Audunsson, Haraldur; Levi, Shaul; Hodges, Floyd

    1992-04-01

    Intraflow structures and magmatic evolution in an extensive and thick (30-60 m) basaltic lava flow are examined on the basis of grain size and composition-dependent magnetic properties of titanomagnetite materials. Microprobe data indicate that the intraflow oxidation state Fe(3+)/Fe(2+) of the initially precipitated primary titanomagnetites increases with falling equilibrium temperature from the flow margins to a maximum near the center, the position of lowest equilibrium temperature. In contrast, Curie temperature measurements indicate that titanomagnetite oxidation increases with height in the flow. Modification of the initially symmetric equilibrium titanomagnetite compositions was caused by subsolidus high-temperature oxidation possibly due to hydrogen loss produced by dissociation of magmatic water, as well as unknown contributions of circulating air and percolating water from above. The titanomagnetites of the basal layer of the flow remain essentially unaltered.

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

    International Nuclear Information System (INIS)

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

    Directory of Open Access Journals (Sweden)

    Phisit Limtrakun

    2013-08-01

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

  5. Geochemistry contribution of Pb isotopes on basalts origin study from Parana basin, Brazil

    International Nuclear Information System (INIS)

    Marques, L.S.; Dupre, B.; Allegre, C.J.

    1990-01-01

    This paper presents thirty new Pb-isotope and concentration data for low- and high-tiO sub(2) continental flood basalts of the Parana Basin. The results obtained from representative samples show significant differences with respect to type and location of these basic rocks. The low- and high-TiO sub(2) basalts from the northern region of the Parana Basin exhibit very similar Pb-isotope compositions. On the other hand, the low-TiO sub(2) basalts of central and southern areas, which exhibit low Sr initial isotope ratios (less than 0,7060), show very small variation in Pb isotope compositions which are highly enriched in radiogenic Pb in comparison with the analogues of northern region. The high-TiO sub(2) basic rocks analysed from northern and central regions have the same values for Pb isotope ratios, which are slightly more radiogenic compared with high-TiO sub(2) basalts from southern region. The data obtained, combined with other geochemical (major and trace elements, including rare earths) and isotope (Sr and Nd) results support the view that the basalts from northern and southern areas of the Parana Basin originated in lithospheric mantle reservoirs with different geochemical characteristics. (author)

  6. Preliminary results of hydrologic testing: The composite Umtanum basalt flow top at borehole RRL-2 (3,568 - 3,781 feet)

    International Nuclear Information System (INIS)

    Strait, S.R.; Spane, F.A. Jr.

    1982-11-01

    This report presents preliminary results and description of hydrologic test activities for the composite Umtanum basalt flow top (3,568--3,781 feet) at Borehole RRL-2. Hydrologic tests conducted include two constant discharge air-lift and four slug tests. Preliminary results indicate an observed hydraulic head for the test interval of 405.7 feet above mean sea level. Transmissivity values determined from hydrologic tests performed, range between 244 to 481 ft 2 /day, with an assigned best estimate of 480 ft 2 /day. The best estimate of equivalent hydraulic conductivity, based on an effective test thickness of 157 feet, is 3.1 ft/day. 7 refs., 9 figs., 3 tabs

  7. 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

  8. 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

  9. Petrogeochemistry of Mesozoic basaltic volcanics in Daqingshan area

    International Nuclear Information System (INIS)

    Li Xiaoguang; Li Ziying; Wei Sanyuan; Qi Da'neng

    2009-01-01

    Through the discussion on petrogeochemistry of Later Mesozoic basaltic volcanics in Daqingshan Basin in Manzhouli area, combined with field observation and the predecessors' study, its magma evolution,genesis and diagenetic structural environment are discussed, and some suggestion are provided for the further work. Basaltic magma in this area is believed to be derived from mantle with incompatible elements which were later participated by some crustal materials. It is a partially melting product of mantle by early metasomatized fluid under lithosphere extension. Through petrogeochemical analysis of the volcanics and the contrast to the adjacent uranium-producing volcanics, it is concluded that this region has structural environment to form magma evolution series which are more favorable for volcanic hydrothermal-type uranium and polymetallic mineralization. (authors)

  10. 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

  11. 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...

  12. Geologic structure of shallow maria. [topography of lunar maria

    Science.gov (United States)

    Dehon, R. A.; Waskom, J. A.

    1975-01-01

    Isopach maps and structural contour maps of the eastern mare basins (30 deg N to 30 deg S; 0 deg to 100 deg E), constructed from measurements of partially buried craters, are presented and discussed. The data, which are sufficiently scattered to yield gross thickness variations, are restricted to shallow maria with less than 1500-2000 m of mare basalts. The average thickness of basalt in the irregular maria is between 200 and 400 m. Correlations between surface topography, basalt thickness, and basin floor structure are apparent in most of the basins that were studied. The mare surface is commonly depressed in regions of thick mare basalts; mare ridges are typically located in regions of pronounced thickness changes; and arcuate mare rilles are confined to thin mare basalts. Most surface structures are attributed to shallow stresses developed within the mare basalts during consolidation and volume reduction.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

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

    1983-03-01

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

  15. Comparison of mechanical and tribotechnical properties of UHMWPE reinforced with basalt fibers and particles

    Science.gov (United States)

    Panin, S. V.; Kornienko, L. A.; Alexenko, V. O.; Qitao, Huang; Ivanova, L. R.

    2016-11-01

    Mechanical and tribotechnical properties of UHMWPE composites reinforced with basalt fibers and particles under dry sliding friction and abrasion were investigated. It is shown that adding of the basalt particles provides higher wear resistance under the dry sliding friction while at abrasion filling by the basalt fibers is more efficient since the wear resistance of the reinforced UHMWPE composites is by 3.7 times higher in contrast with the neat polymer. Wear mechanisms of the polymeric UHMWPE composites under various types of wear are discussed.

  16. Hydrothermal waste package interactions with methane-containing basalt groundwater

    International Nuclear Information System (INIS)

    McGrail, B.P.

    1984-01-01

    Hydrothermal waste package interaction tests were conducted with a mixture of crushed glass, basalt, and steel in methane-containing synthetic basalt groundwater. In the absence of gamma radiolysis, methane was found to have little influence on the corrosion behavior of the waste package constituents. Under gamma radiolysis, methane was found to significantly lower the solution oxidation potential when compared to identical tests without methane. In addition, colloidal hydrocarbon polymers that have been produced under the irradiation conditions of these experiments were not formed. The presence of the waste package constituents apparently inhibited the formation of the polymers. However, the mechanism which prevented their formation was not determined

  17. 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)

  18. Role of syn-eruptive plagioclase disequilibrium crystallization in basaltic magma ascent dynamics.

    Science.gov (United States)

    La Spina, G; Burton, M; De' Michieli Vitturi, M; Arzilli, F

    2016-12-12

    Timescales of magma ascent in conduit models are typically assumed to be much longer than crystallization 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 crystallization and exsolution processes are fundamental to our understanding of such disequilibria and ascent dynamics. Here we use observations from Mount Etna's 2001 eruption and a magma ascent model to constrain timescales for crystallization and exsolution processes. Our results show that plagioclase reaches equilibrium in 1-2 h, whereas ascent times were magma ascent rate and disequilibrium crystallization and exsolution plays a key role in controlling eruption dynamics in basaltic volcanism.

  19. 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.

  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. A LREE-depleted component in the Afar plume: Further evidence from Quaternary Djibouti basalts

    Science.gov (United States)

    Daoud, Mohamed A.; Maury, René C.; Barrat, Jean-Alix; Taylor, Rex N.; Le Gall, Bernard; Guillou, Hervé; Cotten, Joseph; Rolet, Joël

    2010-02-01

    Major, trace element and isotopic (Sr, Nd, Pb) data and unspiked K-Ar ages are presented for Quaternary (0.90-0.95 Ma old) basalts from the Hayyabley volcano, Djibouti. These basalts are LREE-depleted (La n/Sm n = 0.76-0.83), with 87Sr/ 86Sr ratios ranging from 0.70369 to 0.70376, and rather homogeneous 143Nd/ 144Nd ( ɛNd = + 5.9-+ 7.3) and Pb isotopic compositions ( 206Pb/ 204Pb = 18.47-18.55, 207Pb/ 204Pb = 15.52-15.57, 208Pb/ 204Pb = 38.62-38.77). They are very different from the underlying enriched Tadjoura Gulf basalts, and from the N-MORB erupted from the nascent oceanic ridges of the Red Sea and Gulf of Aden. Their compositions closely resemble those of (1) depleted Quaternary Manda Hararo basalts from the Afar depression in Ethiopia and (2) one Oligocene basalt from the Ethiopian Plateau trap series. Their trace element and Sr, Nd, Pb isotope systematics suggest the involvement of a discrete but minor LREE-depleted component, which is probably an intrinsic part of the Afar plume.

  2. Alteration of Basaltic Glass to Mg/Fe-Smectite under Acidic Conditions: A Potential Smectite Formation Mechanism on Mars

    Science.gov (United States)

    Peretyazhko, Tanya; Sutter, Brad; Ming, Douglas W.

    2014-01-01

    Phyllosilicates of the smectite group including Mg- and Fe-saponite and Fe(III)-rich nontronite have been identified on Mars. Smectites are believed to be formed under neutral to alkaline conditions that prevailed on early Mars. This hypothesis is supported by the observation of smectite and carbonate deposits in Noachian terrain on Mars. However, smectite may have formed under mildly acidic conditions. Abundant smectite formations have been detected as layered deposits hundreds of meters thick in intracrater depositional fans and plains sediments, while no large deposits of carbonates are found. Development of mildly acidic conditions at early Mars might allow formation of smectite but inhibit widespread carbonate precipitation. Little is known regarding the mechanisms of smectite formation from basaltic glass under acidic conditions. The objective of this study was to test a hypothesis that Mars-analogue basaltic glass alters to smectite minerals under acidic conditions (pH 4). The effects of Mg and Fe concentrations and temperature on smectite formation from basaltic glass were evaluated. Phyllosilicate synthesis was performed in batch reactors (Parr acid digestion vessel) under reducing hydrothermal conditions at 200 C and 100 C. Synthetic basaltic glass with a composition similar to that of the Gusev crater rock Adirondack (Ground surface APXS measurement) was used in these experiments. Basaltic glass was prepared by melting and quenching procedures. X-ray diffraction (XRD) analysis indicated that the synthesized glass was composed of olivine, magnetite and X-ray amorphous phase. Samples were prepared by mixing 250 mg Adirondack with 0.1 M acetic acid (final pH 4). In order to study influence of Mg concentration on smectite formation, experiments were performed with addition of 0, 1 and 10 mM MgCl2. After 1, 7 and 14 day incubations the solution composition was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the altered glass and formed

  3. Sorption of uranium and cesium by Hanford basalts and associated secondary smectite

    International Nuclear Information System (INIS)

    Ames, L.L.; McGarrah, J.E.; Walker, B.A.; Salter, P.F.

    1982-01-01

    Three characterized basalts and an associated secondary smectite were used in comparative uranium and cesium sorption studies. Experiments utilizing two synthetic characteristic basalt groundwaters at 23 and 60 0 C allowed comparison of increased temperature and carbonate concentration effects on Cs and U sorption. The sorption data were fitted to the Dubinin-Radushkevich (D-R) isotherm, and loading maxima and energetics derived. An increase in temperature caused a decrease in Cs sorption maxima on all solids from all groundwaters studied and an increase in U sorption maxima, especially from the higher-carbonate-content groundwater. Sorption energies were characteristic of ion exchange for both Cs and U sorption processes. Basalt U sorption maxima were relatively insignificant, but smectite U sorption maxima surpassed Cs sorption maxima in both groundwaters at 60 0 C. The uranyl carbonate complexes thus may be relatively temperature-sensitive. Upon removal of excess Fe-oxides from the secondary smectite, U sorption decreased and the D-R isotherm reverted to a normal Freundlich sorption isotherm. Removal of excess Fe-oxides from the basalts and secondary smectite would probably result in Freundlich sorption isotherms for both Cs and U. (Auth.)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  5. Characterization and Distribution of Lunar Mare Basalt Types Using Remote Sensing Techniques. Ph.D. Thesis

    Science.gov (United States)

    Pieters, C.

    1977-01-01

    The types of basal to be found on the moon were identified using reflectance spectra from a variety of lunar mare surfaces and craters as well as geochemical interpretations of laboratory measurements of reflectance from lunar, terrestrial, and meteoritic samples. Findings indicate that major basaltic units are not represented in lunar sample collections. The existence of late stage high titanium basalts is confirmed. All maria contain lateral variations of compositionally heterogenous basalts; some are vertically inhomogenous with distinctly different subsurface composition. Some basalt types are spectrally gradational, suggesting minor variations in composition. Mineral components of unsampled units can be defined if spectra are obtained with sufficient spectral coverage (.3 to 2.5 micron m) and spatial resolution (approximating .5 km).

  6. Komatiites and nickel sulfide ores of the Black Swan area, Yilgarn Craton, Western Australia. 2: Geology and genesis of the orebodies

    Science.gov (United States)

    Dowling, S. E.; Barnes, S. J.; Hill, R. E. T.; Hicks, J. D.

    2004-11-01

    The Black Swan Ultramafic Succession hosts a number of magmatic Fe Ni Cu PGE sulfide ore shoots, ranging from high grade massive ore to low grade disseminated sulfides. Of these, the most economically significant is the Silver Swan massive sulfide orebody, associated with the basal contact of the succession. The deposit varies in thickness between 5 and 20 m, reaches a N S strike length of 75 m, extends for at least 1.2 km of vertical plunge and is open at depth. Overlying matrix (net-textured) ore is rare. Inclusions of dacite are abundant within the lower 5 m of the massive sulfide. They range from angular fragments through smooth sinuous and plumose morphologies to fine lace-like intergrowths with the sulfide matrix, and comprise variable proportions of cores of porphyritic dacite and carapaces with skeletal plagioclase phenocrysts. Dynamic crystallisation and kinetic melting textures in the carapaces indicate that the inclusions have been heated to various temperatures, some well above their liquidus temperature. The composition of the inclusions ranges from a perfect match with the immediate footwall dacites to mixtures of dacite with up to 30% komatiite. The consistent thickness of the inclusion-bearing basal layer within the massive sulphide is interpreted as the extent of 3-D physical connectivity between the inclusions and a partially molten underlying hybrid layer. Primary contacts between the Silver Swan massive sulfide orebody and overlying ultramafic rocks are marked by thin rinds containing coarse-grained chevron-textured chromites with skeletal textures. Compositions of these chromites match those from Kambalda, Perseverance and other localities, and are inconsistent with a metamorphic origin. They are interpreted as markers of primary magmatic contacts. The combination of this feature with the general paucity of matrix ore implies that the massive ore accumulated and solidified before the accumulation of the overlying thick sequence of olivine

  7. 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.

  8. 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

  9. Understanding heat and groundwater flow through continental flood basalt provinces: insights gained from alternative models of permeability/depth relationships for the Columbia Plateau, USA

    Science.gov (United States)

    Burns, Erick R.; Williams, Colin F.; Ingebritsen, Steven E.; Voss, Clifford I.; Spane, Frank A.; DeAngelo, Jacob

    2015-01-01

    Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. Limited in situ permeability (k) data from the CRBG are compatible with a steep permeability decrease (approximately 3.5 orders of magnitude) at 600–900 m depth and approximately 40°C. Numerical simulations incorporating this permeability decrease demonstrate that regional groundwater flow can explain lower-than-expected heat flow in these highly anisotropic (kx/kz ~ 104) continental flood basalts. Simulation results indicate that the abrupt reduction in permeability at approximately 600 m depth results in an equivalently abrupt transition from a shallow region where heat flow is affected by groundwater flow to a deeper region of conduction-dominated heat flow. Most existing heat-flow measurements within the CRBG are from shallower than 600 m depth or near regional groundwater discharge zones, so that heat-flow maps generated using these data are likely influenced by groundwater flow. Substantial k decreases at similar temperatures have also been observed in the volcanic rocks of the adjacent Cascade Range volcanic arc and at Kilauea Volcano, Hawaii, where they result from low-temperature hydrothermal alteration.

  10. Preliminary results of hydrologic testing of the Umtanum Basalt Fracture Zone at borehole RRL-2 (3,781 to 3,827 ft)

    International Nuclear Information System (INIS)

    Strait, S.R.; Spane, F.A. Jr.

    1983-02-01

    This report presents preliminary results and description of hydrologic test activities for the Umtanum Basalt Fracture Zone at Borehole RRL-2, within the test interval 3,781 to 3,827 feet. Hydrologic tests conducted include two short-term, constant discharge pumping tests and two slug tests. Preliminary results indicate an observed hydraulic head for the test interval of 406.7 feet above mean sea level. Transmissivity values determined from hydrologic tests performed range between 205 and 881 ft 2 /day. The best estimate of equivalent hydraulic conductivity, based on an effective test thickness of 6 feet, is 147 ft/day. 8 refs., 6 figs., 3 tabs

  11. Basalt generation at the Apollo 12 site. Part 2: Source heterogeneity, multiple melts, and crustal contamination

    Science.gov (United States)

    Neal, Clive R.; Hacker, Matthew D.; Snyder, Gregory A.; Taylor, Lawrence A.; Liu, Yun-Gang; Schmitt, Roman A.

    1994-01-01

    The petrogenesis of Apollo 12 mare basalts has been examined with emphasis on trace-element ratios and abundances. Vitrophyric basalts were used as parental compositions for the modeling, and proportions of fractionating phases were determined using the MAGFOX prograqm of Longhi (1991). Crystal fractionation processes within crustal and sub-crustal magma chambers are evaluated as a function of pressure. Knowledge of the fractionating phases allows trace-element variations to be considered as either source related or as a product of post-magma-generation processes. For the ilmenite and olivine basalts, trace-element variations are inherited from the source, but the pigeonite basalt data have been interpreted with open-system evolution processes through crustal assimilation. Three groups of basalts have been examined: (1) Pigeonite basalts-produced by the assimilation of lunar crustal material by a parental melt (up to 3% assimilation and 10% crystal fractionation, with an 'r' value of 0.3). (2) Ilmenite basalts-produced by variable degrees of partial melting (4-8%) of a source of olivine, pigeonite, augite, and plagioclase, brought together by overturn of the Lunar Magma Ocean (LMO) cumulate pile. After generation, which did not exhaust any of the minerals in the source, these melts experienced closed-system crystal fractionation/accumulation. (3) Olivine basalts-produced by variable degrees of partial melting (5-10%) of a source of olivine, pigeonite, and augite. After generation, again without exhausting any of the minerals in the source, these melts evolved through crystal accumulation. The evolved liquid counterparts of these cumulates have not been sampled. The source compositions for the ilmenite and olivine basalts were calculated by assuming that the vitrophyric compositions were primary and the magmas were produced by non-modal batch melting. Although the magnitude is unclear, evaluation of these source regions indicates that both be composed of early- and

  12. Microseismic monitoring of columnar jointed basalt fracture activity: a trial at the Baihetan Hydropower Station, China

    Science.gov (United States)

    Chen, Bing-Rui; Li, Qing-Peng; Feng, Xia-Ting; Xiao, Ya-Xun; Feng, Guang-Liang; Hu, Lian-Xing

    2014-10-01

    Severe stress release has occurred to the surrounding rocks of the typically columnar jointed basalt after excavation at the Baihetan Hydropower Station, Jinsha River, China, where cracking, collapse, and other types of failure may take place occasionally due to relaxation fracture. In order to understand the relaxation fracture characteristics of the columnar jointed basalt in the entire excavation process at the diversion tunnel of the Baihetan Hydropower Station, real-time microseismic monitoring tests were performed. First, the applicability of a geophone and accelerometer was analyzed in the columnar jointed basalt tunnel, and the results show that the accelerometer was more applicable to the cracking monitoring of the columnar jointed basalt. Next, the waveform characteristics of the microseismic signals were analyzed, and the microseismic signals were identified as follows: rock fracture signal, drilling signal, electrical signal, heavy vehicle passing signal, and blast signal. Then, the attenuation characteristics of the microseismic signals in the columnar jointed basalt tunnel were studied, as well as the types and characteristics of the columnar jointed basalt fracture. Finally, location analysis was conducted on the strong rock fracture events, in which four or more sensors were triggered, to obtain the temporal and spatial evolution characteristics and laws of the columnar jointed basalt relaxation fracture after excavation. The test results are not only of important reference value to the excavation and support of diversion tunnel at the Baihetan Hydropower Station, but also of great referential significance and value to the conduction of similar tests.

  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. Laboratory Study on Properties of Diatomite and Basalt Fiber Compound Modified Asphalt Mastic

    Directory of Open Access Journals (Sweden)

    Yongchun Cheng

    2017-01-01

    Full Text Available In order to improve the performance of asphalt mastic, some researchers have added diatomite or basalt fiber as a modifier to the asphalt mastic, and the results show that some properties of the asphalt mastic were improved. For the simultaneous addition of diatomite and basalt fiber, two kinds of modifier, compound modified asphalt mastic had not been reported; in this paper, thirteen groups of diatomite and basalt fiber (DBFCMAM compound modified asphalt mastic with different content were prepared to study the performance. Softening point, cone penetration, viscosity, and DSR tests were conducted, for the high temperature performance evaluation of DBFCMAM, whereas force ductility and BBR tests were used in the low temperature performance study of the DBFCMAM. The results demonstrated that the high temperature performance of DBFCMAM was increased; moreover, the low temperature performance of DBFCMAM improved by diatomite and basalt fiber according to the results of the force ductility test; however, the conclusion of the BBR test data was inconsistent with the force ductility test. In summary, the high temperature and low temperature properties of DBFCMAM had been improved.

  15. 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.

  16. Low velocity impact properties of intra-ply hybrid composites based on basalt and nylon woven fabrics

    International Nuclear Information System (INIS)

    Dehkordi, Majid Tehrani; Nosraty, Hooshang; Shokrieh, Mahmood Mehrdad; Minak, Giangiacomo; Ghelli, Daniele

    2010-01-01

    In this paper, the low velocity impact behavior of homogenous and hybrid composite laminates reinforced by basalt-nylon intra-ply fabrics was experimentally investigated. Epoxy resin was used as matrix material. The purpose of using this hybrid composite is to combine the good mechanical properties of basalt fiber with the excellent impact resistant of nylon fiber. Five different types of woven fabrics were used as reinforcement with different volume percentages of nylon (0%, 25%, 33.3%, 50% and 100%). The effect of nylon/basalt fiber content on maximum force, maximum deflection, residual deflection, total absorbed energy, elastic energy, size and type of damage were studied at several low velocity impact nominal energy levels (16, 30 and 40 J). The results indicate that impact performance of these composites is significantly affected by the nylon/basalt fiber content. The visual inspection and ultrasonic C-scan of the impact damaged specimens reveals that content of nylon/basalt fiber controls the type and size of damage.

  17. 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

  18. 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

  19. 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.

  20. Trace element and isotopic compositions of Vietnamese basalts: implications for mantle dynamics in the southeast Asian region

    International Nuclear Information System (INIS)

    Nguyen, H.; Fower, M.; Nguyen, H.; Nguyen, X.B.; Nguyen, T.Y.

    1996-01-01

    Cenozoic basalts in Indo-China are part of a regional melting episode along the rifted Eurasian margin. Trace element and isotopic compositions of Vietnamese basalts are used to place constraints on the extent of lithospheric and asthenosphere contributions to the melts and possible mantle dynamic implications. The 87 Sr/ 86 Sr, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb isotopic ratios of the basalts reflect minimal crustal wall rock reaction, and variable enrichment in EM1 and EM2 of a 208 Pb-rich MORB-like source. Some, but not all, of this variation corresponds to the age of lithospheric sector penetrated. Basalts erupted through a cratonic, central sector (e.g. at Quang Ngai, Pleiku, Song Cau, Kong Plong, and Buon Ma Thuot) and off-cratonic, southwest sector (e.g. Phuoc Long) resemble those of EM2-rich basalts from southern and southeaster China and the South China Sea. Basalts from an off-cratonic, southeast sector (e.g. from Dalat, Xuan Loc, and the offshore Ile des Cendres-Phu Cuy complex) reflect mixing between a low- 206 Pb/ 204 Pb, high- 208 Pb/ 204 Pb, EM1-like component, and resemble basalts from northwest Taiwan, eastern and northeastern China, and parts of the Japan Sea. While EM2 tends to characterise lithospheric sectors, presence of EM1 in off-cratonic rather than cratonic basalts implies an asthenosphere rather than lithospheric source. Pervasive presence of EM1 in southeast Asian and marginal basin asthenosphere corresponds with thermally-anomalous mantle and may involve delaminated cratonic substrate entrained by mobile, extruded asthenosphere. (authors)

  1. Technological characterization of basaltic rocks of Canoas I Hydroelectric Power Plant, Paranapanema river, Sao Paulo - Parana states, Brazil; Caracterizacao tecnologica das rochas basalticas da Usina Hidroeletrica Canoas I, Rio Paranapanema, SP/PR

    Energy Technology Data Exchange (ETDEWEB)

    Marrano, Antonio

    1997-07-01

    Basaltic litotypes from the rock mass foundation of Canoas I Hydroelectric Power Plant were submitted to technological characterization tests, in order to verify their suitability as construction material. Physical and mechanical properties (density, porosity, water absorption, ultrasonic velocity, compressive and splitting tensile strength, among others) were determined, besides petrographic analyses. Weather ability tests were also performed, not only through wetting-drying cycles and by immersion in ethylene glycol but by outdoor exposure as well, using crushed and core drilled specimens. Detailed procedures for the weather ability test using core specimens from rotary drilling are given. It is analyzed the influence of a geological feature (fault zone, about 10 meters thick and 20 degrees dip), that occurs in the rock mass foundation, on the technological properties of these rocks. Basaltic litotypes selected as construction material are then pointed out. (author)

  2. Trace element and isotopic compositions of Vietnamese basalts: implications for mantle dynamics in the southeast Asian region; Compositions isotopiques et en elements en trace des basaltes vietnamiens: implications pour la dynamique du manteau en Asie du Sud-Est

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, H.; Fower, M. [Illinois Univ., Chicago, IL (United States); Nguyen, H. [Tokyo Univ. (Japan); Nguyen, X.B.; Nguyen, T.Y. [Institute of Nuclear Science and Technology, Hanoi (Viet Nam)

    1996-12-31

    Cenozoic basalts in Indo-China are part of a regional melting episode along the rifted Eurasian margin. Trace element and isotopic compositions of Vietnamese basalts are used to place constraints on the extent of lithospheric and asthenosphere contributions to the melts and possible mantle dynamic implications. The {sup 87}Sr/{sup 86}Sr, {sup 207}Pb/{sup 204}Pb, and {sup 208}Pb/{sup 204}Pb isotopic ratios of the basalts reflect minimal crustal wall rock reaction, and variable enrichment in EM1 and EM2 of a {sup 208}Pb-rich MORB-like source. Some, but not all, of this variation corresponds to the age of lithospheric sector penetrated. Basalts erupted through a cratonic, central sector (e.g. at Quang Ngai, Pleiku, Song Cau, Kong Plong, and Buon Ma Thuot) and off-cratonic, southwest sector (e.g. Phuoc Long) resemble those of EM2-rich basalts from southern and southeaster China and the South China Sea. Basalts from an off-cratonic, southeast sector (e.g. from Dalat, Xuan Loc, and the offshore Ile des Cendres-Phu Cuy complex) reflect mixing between a low- {sup 206}Pb/{sup 204}Pb, high-{sup 208}Pb/{sup 204}Pb, EM1-like component, and resemble basalts from northwest Taiwan, eastern and northeastern China, and parts of the Japan Sea. While EM2 tends to characterise lithospheric sectors, presence of EM1 in off-cratonic rather than cratonic basalts implies an asthenosphere rather than lithospheric source. Pervasive presence of EM1 in southeast Asian and marginal basin asthenosphere corresponds with thermally-anomalous mantle and may involve delaminated cratonic substrate entrained by mobile, extruded asthenosphere. (authors) 85 refs.

  3. Evolution of depleted mantle: The lead perspective

    Science.gov (United States)

    Tilton, George R.

    1983-07-01

    Isotopic data have established that, compared to estimated bulk earth abundances, the sources of oceanic basaltic lavas have been depleted in large ion lithophile elements for at least several billions of years. Various data on the Tertiary-Mesozoic Gorgona komatiite and Cretaceous Oka carbonatite show that those rocks also sample depleted mantle sources. This information is used by analogy to compare Pb isotopic data from 2.6 billion year old komatiite and carbonatite from the Suomussalmi belt of eastern Finland and Munro Township, Ontario that are with associated granitic rocks and ores that should contain marked crustal components. Within experimental error no differences are detected in the isotopic composition of initial Pb in either of the rock suites. These observations agree closely with Sr and Nd data from other laboratories showing that depleted mantle could not have originated in those areas more than a few tenths of billions of years before the rocks were emplaced. On a world-wide basis the Pb isotope data are consistent with production of depleted mantle by continuous differentiation processes acting over approximately the past 3 billion years. The data show that Pb evolution is more complex than the simpler models derived from the Rb-Sr and Sm-Nd systems. The nature of the complexity is still poorly understood.

  4. Genetic interpretation of lead-isotopic data from the Columbia River basalt group, Oregon, Washington, and Idaho.

    Science.gov (United States)

    Church, S.E.

    1985-01-01

    Lead-isotopic data for the high-alumina olivine plateau basalts and most of the Colombia River basalt group plot within the Cascade Range mixing array. The data for several of the formations form small, tight clusters and the Nd and Sr isotopic data show discrete variation between these basalt groups. The observed isotopic and trace-element data from most of the Columbia River basalt group can be accounted for by a model which calls for partial melting of the convecting oceanic-type mantle and contamination by fluids derived from continental sediments which were subducted along the trench. These sediments were transported in the low-velocity zone at least 400 km behind the active arc into a back-arc environment represented by the Columbia Plateau province. With time, the zone of melting moved up, resulting in the formation of the Saddle Mt basalt by partial melting of a 2600 m.y.-old sub-continental lithosphere characterized by high Th/U, Th/Pb, Rb/Sr and Nd/Sm ratios and LREE enrichment. Partial melting of old sub-continental lithosphere beneath the continental crust may be an important process in the formation of continental tholeiite flood basalt sequences world-wide. -L.di H.

  5. New absolute paleointensity determinations for the Permian-Triassic boundary from the Kuznetsk Trap Basalts.

    Science.gov (United States)

    Kulakov, E.; Metelkin, D. V.; Kazansky, A.

    2015-12-01

    We report the results of a pilot absolute paleointensity study of the ~250 Ma basalts of Kuznetsk traps (Kuznetsk Basin, Altai-Sayan folded area). Studied samples are characterized by a reversed polarity of natural remanent magnetization that corresponds to the lower part of Siberian Trap basalts sequence. Geochemical similarity of Kuznets basalts with those from Norilsk region supports this interpretation. Primary origin of thermal remanence in our sample is confirmed by a positive backed contact test. Rock magnetic analyses indicate that the ChRM is carried by single-domain titanomagnetite. The Coe-version of the Thellier-Therllier double-heating method was utilized for the paleointensity determinations. In contrast to the previous studies of the Permian-Triassic Siberian trap basalts, our data indicate that by the P-T boundary the paleofield intensity was relatively high and comparable with geomagnetic field strength for the last 10 millions of years. New results question the duration of the "Mesozoic dipole-low".

  6. Permanent groundwater storage in basaltic dyke fractures and termite mound viability

    Science.gov (United States)

    Mège, Daniel; Rango, Tewodros

    2010-04-01

    Many basaltic dykes of the Ethiopian flood basalt province are observed in the northwestern Ethiopian lowlands. In this area, the termites preferentially build their epigeous mounds on the top of dolerite dykes. The relationship between termite mounds and dykes is investigated from the analysis of their distribution along one of these dykes, of thickness 2-5 m, that we could follow over 2000 m. Termite mounds are periodically spaced (mean distance 63 m, R2 = 0.995), and located exclusively where the topographic relief of the dyke is not more than 2 m above the surrounding area. From these observations and from the geological context, a hydrological circuit model is proposed in which (1) dykes are preferential conduits for groundwater drainage during the rainy season due to pervasive jointing, (2) during the dry season, the portion of the dyke forming a local topographic relief area dries up more quickly than the surroundings, the elevation difference between the dyke summit and the surroundings being a factor restricting termite mound development. For dyke topographic relief >2 m, drying is an obstacle for maintaining the appropriate humidity for the termite colony life. Periodic termite mound spacing is unlikely to be related to dyke or other geological properties. It is more likely related to termite population behaviour, perhaps to clay shortage, which restricts termite population growth by limiting the quantity of building material available for mound extension, and triggers exploration for a new colonization site that will be located along the dyke at a distance from the former colony that may be controlled by the extent of the zone covered by its trail pheromones. This work brings out the importance of dykes in channelling and storing groundwater in semiarid regions, and shows that dykes can store groundwater permanently in such settings even though the dry season is half the year long. It contributes also to shedding light on water supply conditions

  7. 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.

  8. Melting relations of model lherzolite in the system CaO-MgO-Al2O3-SiO2 at 2.4-3.4 GPa and the generation of komatiites

    Science.gov (United States)

    Gudfinnsson, Gudmundur H.; Presnall, Dean C.

    1996-12-01

    Isobarically invariant phase relations in the CaO-MgO-Al2O3-SiO2 system (CMAS) involving the lherzolite phase assemblage in equilibrium with liquid have been determined at 2.4-3.4 GPa. These phase relations form the solidus of model lherzolite in the CMAS system. Our data, which include determinations of all phase compositions, are in excellent agreement with the 3.0 and 4.0 GPa points of Milholland and Presnall [1991] and Davis and Schairer [1965], respectively. The invariant transition on the P-T solidus curve from spinel- to garnet-lherzolite at 3.0 GPa, 1575°C [Milholland and Presnall, 1991], is confirmed, but we observe that the theoretically required temperature depression on the solidus curve at this point is not experimentally detectable. Composition trends along the solidus take a sharp turn at the transition. In the spinel-lherzolite stability field, melt compositions become increasingly Fo-normative and less En-normative with increasing pressure, but become less Fo-normative and more pyroxenitic as pressure increases in the garnet-lherzolite stability field. Calculated melting reactions indicate that forsterite is in reaction relationship with the melt up to 3.0 GPa. Orthopyroxene is also in reaction relationship at pressures higher than just over 2.8 GPa and is the only phase in reaction relationship with the melt in the garnet-lherzolite stability field. Comparison of the normative compositions and the CaO/Al2O3 values of the komatiites of Gorgona Island and of the Reliance Formation in Zimbabwe with the compositions of liquids along the solidus of model lherzolite in the CMAS system indicates that the former komatiites were generated at pressures close to 3.7 GPa and the latter at close to 4.5 GPa, assuming that the melt generation occurred in the presence of the complete garnet-lherzolite assemblage.

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

    Science.gov (United States)

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

    2016-10-01

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

  10. Influence of length-to-diameter ratio on shrinkage of basalt fiber concrete

    Science.gov (United States)

    Ruijie, MA; Yang, Jiansen; Liu, Yuan; Zheng, Xiaojun

    2017-09-01

    In order to study the shrinkage performance of basalt concrete, using the shrinkage rate as index, the work not only studied the influence of different length-to-diameter ratio (LDR) on plastic shrinkage and drying shrinkage of basalt fiber concrete, but also analyzed the action mechanism. The results show that when the fiber content is 0.1%, the LDR of 800 and 1200 take better effects on reducing plastic shrinkage, however the fiber content is 0.3%, that of LDR 600 is better. To improve drying shrinkage, the fiber of LDR 800 takes best effect. In the concrete structure, the adding basalt fibers form a uniform and chaotic supporting system, optimize the pore and the void structure of concrete, make the material further compacted, reduce the water loss, so as to decrease the shrinkage of concrete effectively.

  11. 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

  12. Mobilization of manganese by basalt associated Mn(II)-oxidizing bacteria from the Indian Ridge System

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; Mourya, B.S.; Krishnamurthi, S.; Meena, R.M.; LokaBharathi, P.A.

    The Indian Ridge System basalt bearing Mn-oxide coatings had todorokite as the major and birnesite as the minor mineral. We posit that microorganisms associated with these basalts participate in the oxidation of Mn and contribute to mineral...

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

    International Nuclear Information System (INIS)

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

    1980-09-01

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

  14. 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

  15. Giant Plagioclase Basalts, eruption rate versus time

    Indian Academy of Sciences (India)

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

    I found the GPB lavas to be very interest- ing because in some ... by Venkatesan et al (1993) and thus in a way validates my approach. ... and age calculation of lavas from phenocrysts. Keywords. Deccan Trap; Giant Plagioclase Basalts; eruption duration. Proc. Indian Acad. Sci. (Earth Planet. Sci.), 111, No. 4, December ...

  16. 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...... away from the rift . The low-Ti samples include a large proportion of high-MgO basalts and can be related by a common model of low-pressure fractionation. Fractionation correction to 13 % MgO shows only little variation in their primitive major element contents, suggesting very similar origins...

  17. 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

  18. Crystallization behaviors and seal application of basalt based glass-ceramics

    Science.gov (United States)

    Ateş, A.; Önen, U.; Ercenk, E.; Yılmaz, Ş.

    2017-02-01

    Basalt based glass-ceramics were prepared by conventional melt-quenching technique and subsequently converted to glass-ceramics by a controlled nucleation and crystallization process. Glass materials were obtained by melt at 1500°C and quenched in cold water. The powder materials were made by milling and spin coating. The powders were applied on the 430 stainless steel interconnector material, and heat treatment was carried out. The interface characteristics between the glass-ceramic layer and interconnector were investigated by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The results showed that the basalt base glass-ceramic sealant material exhibited promising properties to use for SOFC.

  19. The 1994-2001 eruptive period at Rabaul, Papua New Guinea: Petrological and geochemical evidence for basalt injections into a shallow dacite magma reservoir, and significant SO2 flux

    Science.gov (United States)

    Patia, H.; Eggins, S. M.; Arculus, R. J.; McKee, C. O.; Johnson, R. W.; Bradney, A.

    2017-10-01

    The eruptions that began at Rabaul Caldera on 19 September 1994 had two focal points, the vents Tavurvur and Vulcan, located 6 km apart on opposing sides of the caldera. Vulcan eruptives define a tight cluster of dacite compositions, whereas Tavurvur eruptives span an array from equivalent dacite compositions to mafic andesites. The eruption of geochemically and mineralogically identical dacites from both vents indicates sourcing from the same magma reservoir. This, together with previously reported H2O-CO2 volatile contents of dacite melt inclusions, a caldera-wide seismic low-velocity zone, and a seismically active caldera ring fault structure are consistent with the presence at 3-6 km depth of an extensive, tabular dacitic magma body having volume of about 15-150 km3. The Tavurvur andesites form a linear compositional array and have strongly bimodal phenocryst assemblages that reflect dacite hybridisation with a mafic basalt. The moderately large volume SO2 flux documented in the Tavurvur volcanic plume (and negligible SO2 flux in the Vulcan plume) combined with high dissolved S contents of basaltic melt inclusions trapped in olivine of Tavurvur eruptives, indicate that the amount of degassed basaltic magma was 0.1 km3 and suggest that the injection of this magma was confined to the Tavurvur-side (eastern to northeastern sector) of the caldera. Circumstantial evidence suggests that the eruption was triggered and evolved in response to a series of basaltic magma injections that may have commenced in 1971 and continued up until at least the start of the 1994 eruptions. The presence of zoned plagioclase phenocrysts reflecting older basalt-dacite interaction events (i.e. anorthite cores overgrown with thick andesine rims), evaluation of limited available data for the products of previous eruptions in 1878 and 1937-1943, and the episodic occurrence of major intra-caldera seismo-deformational events indicates that the shallow magma system at Rabaul Caldera is

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-01

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

  1. Impact behavior of basalt/epoxy composite: Comparison between flat and twill fabric

    Science.gov (United States)

    Papa, I.; Ricciardi, M. R.; Antonucci, V.; Langella, A.; Lopresto, V.

    2018-05-01

    Two types of basalt fibre reinforced epoxy laminates were realized by overlapping flat and twill woven basalt fabrics by resin infusion. Rectangular specimens, cut from the panels were impacted at penetration and at increasing energy values, to investigate the damage onset and propagation. A non-destructive technique, Ultrasound testing (UT), was adopted to investigate the internal damage. Despite the difficulties to obtain information by UT method due to the high amount of signal absorbed, the technique, properly calibrated, proved to be very useful in providing information about the presence, the shape and the extent of the delaminations. The results were compared at the aim to investigate the effect of the fiber architecture (textile). The experimental results indicate a similar impact behavior between basalt flat and twill composites but in the case of the twill a minor delaminated area was detected, even if a higher absorbed energy was recorded

  2. Pb, Nd and Sr isotopes in oceanic ferromanganese deposits and ocean floor basalts

    International Nuclear Information System (INIS)

    O'Nions, R.K.; Carter, S.R.; Cohen, R.S.; Evensen, N.M.; Hamilton, P.J.

    1978-01-01

    The Pb-, Nd-, and Sr-isotope compositions of oceanic ferromanganese deposits, together with the Nd- and Sr-isotope compositions of altered ocean-floor basalts, are here reported. These data are used to evaluate these metals as sources in both the oceans and ocean ferromanganese deposits and the extent to which ocean-floor basalts may be a source of, or a sink for, these metals. (author)

  3. ´Áā lava flows in the Deccan Volcanic Province, India, and their significance for the nature of continental flood basalt eruptions

    Science.gov (United States)

    Brown, Richard J.; Blake, S.; Bondre, N. R.; Phadnis, V. M.; Self, S.

    2011-08-01

    Newly identified ´áā lava flows outcrop intermittently over an area of ~110 km2 in the western Deccan Volcanic Province (DVP), India. They occur in the upper Thakurvadi Formation in the region south of Sangamner. The flows, one of which is compound, are 15-25 m thick, and exhibit well-developed basal and flow-top breccias. The lavas have microcrystalline groundmasses and are porphyritic or glomerocrystic and contain phenocrysts of olivine, clinopyroxene or plagioclase feldspar. They are chemically similar to compound pāhoehoe flows at a similar stratigraphic horizon along the Western Ghats. Petrographic and geochemical differences between ´áā flows at widely spaced outcrops at the same stratigraphic horizon suggest that they are the product of several eruptions, potentially from different sources. Their presence in the DVP could suggest relative proximity to vents. This discovery is significant because ´áā lavas are generally scarce in large continental flood basalt provinces, which typically consist of numerous inflated compound pāhoehoe lobes and sheet lobes. Their scarcity is intriguing, and may relate to either their occurrence only in poorly preserved or exposed proximal areas or to the flat plateau-like topography of flood basalt provinces that may inhibit channelization and ´áā formation, or both. In this context, the ´áā flow fields described here are inferred to be the products of eruptions that produced unusually high-effusion-rate lavas compared to typical flood basalt eruptions. Whether these phases were transitional to lower intensity, sustained eruptions that fed extensive low effusion rate pāhoehoe flow fields remains unclear.

  4. 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.

  5. 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

  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. 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

  8. 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.

  9. 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

  10. Age relationships and tectonic implications of late Cenozoic basaltic volcanism in Northland, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Smith, I E.M. [Department of Geology, Auckland University, Auckland (New Zealand); Okada, T [Okayama University of Science, Hiruzen Research Institute, Okayama (Japan); Itaya, T [Okayama University of Science, Hiruzen Research Institute, Okayama (Japan); Black, P M [Department of Geology, Auckland University, Auckland (New Zealand)

    1993-07-01

    An episode of late Miocene-Recent essentially basaltic volcanism is the latest in a sequence of magmatic events recognised in the tectonically complex geological development of the Northland Peninsula. New K-Ar dates together with an extensive collection of new major and trace element chemical analyses prompt a reassessment of the significance of these late Cenozoic basalts. The main time/space groupings recognised are Tertiary volcanics in the Kaikohe-Bay of Islands, Puhipuhi, Ti Point, and Stony Batter areas and Quaternary basalts in the Kaikohe-Bay of Islands and Whangarei areas and at Tara. Basalts in the Kaikohe-Bay of Islands area are transitional to alkalic in character, while those in the south are transitional to tholeiitic, with the Ti Point and Stony Batter rocks being geochemically distinct. A consistent model for these observations is that the magmas originate from different levels of a layered mantle source in which the upper part carries a geochemical signature inherited from an earlier subduction event. (author). 27 refs., 7 figs., 1 tab.

  11. Age relationships and tectonic implications of late Cenozoic basaltic volcanism in Northland, New Zealand

    International Nuclear Information System (INIS)

    Smith, I.E.M.; Okada, T.; Itaya, T.; Black, P.M.

    1993-01-01

    An episode of late Miocene-Recent essentially basaltic volcanism is the latest in a sequence of magmatic events recognised in the tectonically complex geological development of the Northland Peninsula. New K-Ar dates together with an extensive collection of new major and trace element chemical analyses prompt a reassessment of the significance of these late Cenozoic basalts. The main time/space groupings recognised are Tertiary volcanics in the Kaikohe-Bay of Islands, Puhipuhi, Ti Point, and Stony Batter areas and Quaternary basalts in the Kaikohe-Bay of Islands and Whangarei areas and at Tara. Basalts in the Kaikohe-Bay of Islands area are transitional to alkalic in character, while those in the south are transitional to tholeiitic, with the Ti Point and Stony Batter rocks being geochemically distinct. A consistent model for these observations is that the magmas originate from different levels of a layered mantle source in which the upper part carries a geochemical signature inherited from an earlier subduction event. (author). 27 refs., 7 figs., 1 tab

  12. Site identification presentation: Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1979-11-01

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

  13. 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

  14. Alteration of basaltic glasses from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

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

  15. Basaltic rocks analyzed by the Spirit rover in Gusev crater

    Science.gov (United States)

    McSween, H.Y.; Arvidson, R. E.; Bell, J.F.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; Clark, B. C.; Crisp, J.A.; Crumpler, L.S.; Des Marias, D.J.; Farmer, J.D.; Gellert, Ralf; Ghosh, A.; Gorevan, S.; Graff, T.; Grant, J.; Haskin, L.A.; Herkenhoff, K. E.; Johnson, J. R.; Jolliff, B.L.; Klingelhoefer, G.; Knudson, A.T.; McLennan, S.; Milam, K.A.; Moersch, J.E.; Morris, R.V.; Rieder, R.; Ruff, S.W.; De Souza, P.A.; Squyres, S. W.; Wanke, H.; Wang, A.; Wyatt, M.B.; Yen, A.; Zipfel, J.

    2004-01-01

    The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain ???25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mo??ssbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.

  16. 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....

  17. Environmental resistance and mechanical performance of basalt and glass fibers

    International Nuclear Information System (INIS)

    Wei Bin; Cao Hailin; Song Shenhua

    2010-01-01

    The treated basalt and glass fibers with sodium hydroxide and hydrochloric acid solutions for different times were analyzed, respectively. This paper summarized the mass loss ratio and the strength maintenance ratios of the fibers after treatment. The fibers' surface corrosion morphologies were characterized using scanning electron microscopy and their compositions were detected using energy dispersive X-ray spectroscopy. The acid resistance was much better than the alkali resistance for the basalt fibers. Nevertheless, for the glass fibers the situation is different: the acid resistance was almost the same as the alkali resistance. Among the two types of aqueous environments evaluated, the alkali solution is the most aggressive to the fibers' surface. The possible corrosion mechanisms are revealed.

  18. Erosion by flowing lava: Geochemical evidence in the Cave Basalt, Mount St. Helens, Washington

    Science.gov (United States)

    Williams, D.A.; Kadel, S.D.; Greeley, R.; Lesher, C.M.; Clynne, M.A.

    2004-01-01

    We sampled basaltic lava flows and underlying dacitic tuff deposits in or near lava tubes of the Cave Basalt, Mount St. Helens, Washington to determine whether the Cave Basalt lavas contain geochemical evidence of substrate contamination by lava erosion. The samples were analyzed using a combination of wavelength-dispersive X-ray fluorescence spectrometry and inductively-coupled plasma mass spectrometry. The results indicate that the oldest, outer lava tube linings in direct contact with the dacitic substrate are contaminated, whereas the younger, inner lava tube linings are uncontaminated and apparently either more evolved or enriched in residual liquid. The most heavily contaminated lavas occur closer to the vent and in steeper parts of the tube system, and the amount of contamination decreases with increasing distance downstream. These results suggest that erosion by lava and contamination were limited to only the initially emplaced flows and that erosion was localized and enhanced by vigorous laminar flow over steeper slopes. After cooling, the initial Cave Basalt lava flows formed an insulating lining within the tubes that prevented further erosion by later flows. This interpretation is consistent with models of lava erosion that predict higher erosion rates closer to sources and over steeper slopes. A greater abundance of xenoliths and xenocrysts relative to xenomelts in hand samples indicates that mechanical erosion rather than thermal erosion was the dominant erosional process in the Cave Basalt, but further sampling and petrographic analyses must be performed to verify this hypothesis. ?? Springer-Verlag 2003.

  19. Sr isotopic evidence on the spilitic degradation of the Deccan basalt

    International Nuclear Information System (INIS)

    Subbarao, K.V.

    2000-01-01

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

  20. Estimation of the geological age of oceanic basalts by track method

    International Nuclear Information System (INIS)

    Komarov, A.N.; Krylov, A.Ya.

    1977-01-01

    The method is described of the determination of the thermostability of tracks applied to oceanic basalts and the comparison is carried out of age values obtained for the same samples by the track method and by the potassium-argon method. The obtained results allow to consider that the track method is quite practicable for the dating of oceanic basalts on the condition that natural annealing of a part of tracks of the spontaneous uranium fission is taken into accout. For glasses of the other origin - tektites - such approach results in the agreement of the obtained values with the results of potassium-argon method

  1. Mars weathering analogs - Secondary mineralization in Antarctic basalts

    Science.gov (United States)

    Berkley, J. L.

    1982-01-01

    Alkalic basalt samples from Ross Island, Antarctica, are evaluated as terrestrial analogs to weathered surface materials on Mars. Secondary alteration in the rocks is limited to pneumatolytic oxidation of igneous minerals and glass, rare groundmass clay and zeolite mineralization, and hydrothermal minerals coating fractures and vesicle surfaces. Hydrothermal mineral assemblages consist mainly of K-feldspar, zeolites (phillipsite and chabazite), calcite, and anhydrite. Low alteration rates are attributed to cold and dry environmental factors common to both Antarctica and Mars. It is noted that mechanical weathering (aeolian abrasion) of Martian equivalents to present Antarctic basalts would yield minor hydrothermal minerals and local surface fines composed of primary igneous minerals and glass but would produce few hydrous products, such as palagonite, clay or micas. It is thought that leaching of hydrothermal vein minerals by migrating fluids and redeposition in duricrust deposits may represent an alternate process for incorporating secondary minerals of volcanic origin into Martian surface fines.

  2. Trace Element Abundances in Eucrite Basalts: Enrichment or Depletion?

    Science.gov (United States)

    Castle, N. R.

    2018-05-01

    It is not clear how incompatible trace element (ITE) variation in eucrite basalts originated. Here, mechanisms for relative ITE enrichment or depletion are experimentally evaluated in an attempt to reconcile the Stannern and main group eucrites.

  3. 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. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, which allows a shape to be formed prior to the cure, and is then 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. Basalt fibers are used for the reinforcement in the composite system. 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. Continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material.

  4. Investigation of novel composite material based on extra-heavy concrete and basalt fiber for gamma radiation protection properties

    International Nuclear Information System (INIS)

    Romanenko, Yi.M.; Nosovs'kij, A.V.; Gulyik, V.Yi.; Golyuk, M.Yi.

    2018-01-01

    The paper presents a new composite material for radiation protection based on extra-heavy concrete reinforced by basalt fiber. Basalt fiber is a new material for concrete reinforcement, which provides improved mechanical characteristics of concrete, reduces the level of microcracks and increases the durability of concrete. Within the scope of present work, the gamma-ray radiation protection properties of concrete reinforced with basalt fiber was modeled. Two types of extra-heavy concrete were used for this paper. The main gamma-ray attenuation coefficients such as mean atomic number, mean atomic mass, mean electron density, effective atomic number, effective electron density, Murty effective atomic number were analyzed with help of WinXCom software. It has been shown that the addition of basalt fiber to concrete does not impair its gamma-ray radiation shielding properties. With increasing the basalt fiber dosage in concrete, the radiation properties against gamma radiation are improved.

  5. Experimental research on the microstructure and compressive and tensile properties of nano-SiO2 concrete containing basalt fibers

    Directory of Open Access Journals (Sweden)

    Qinyong Ma

    2017-09-01

    Full Text Available Urban underground space resources are gaining increasing attention for the sustainable development of cities. Traditional concrete cannot meet the needs of underground construction. High-performance concrete was prepared using varying dosages of nano-SiO2 and basalt fiber, and its compressive and tensile strength was measured. The concrete microstructure was analyzed and used to assess the mechanisms through which the nano-SiO2 and basalt fibers affect the strength of concrete. The cement hydration productions in concrete produced varied with the dosage of nano-SiO2. When the nano-SiO2 dosage was between 0 and 1.8%, the mass of the C-S-H gel and AFt crystals increased gradually with the nano-SiO2 dosage. When the nano-SiO2 dosage was 1.2%, optimum amounts of C-S-H gel and AFt crystals existed, and the compactness of concrete was well, which agreed with the results of the compressive strength tests. When the basalt-fiber dosage was between 3 and 4 kg/m3, the basalt fibers and the cement matrix were closely bonded, and the splitting tensile strength of the concrete markedly improved. When the basalt-fiber dosage exceeded 5 kg/m3, the basalt fibers clustered together, resulting in weak bonding between the basalt fibers and the cement matrix, consequently, the basalt fibers were easily pulled apart from the cement. When the nano-SiO2 and basalt fiber dosages were 1.2% and 3 kg/m3, respectively, the compactness of the concrete microstructure was well and the strength enhancement was the greatest; additionally, the compressive strength and splitting tensile strength were 9.04% and 17.42%, respectively, greater than those of plain concrete. The macroscopic tests on the mechanical properties of the nano-SiO2 concrete containing basalt fibers agreed well with the results of microstructure analysis.

  6. water alteration processes and kinetics of basaltic glasses, natural analogue of nuclear glasses

    International Nuclear Information System (INIS)

    Techer, I.; Advocat, Th.; Vernaz, E.; Lancelot, J.R.; Liotard, J.M.

    1997-01-01

    Dissolution experiments of a basaltic glass were carried out at 90 deg C for different reaction progresses. The initial dissolution rate was compared with values obtained for rhyolitic glass and the R7T7 nuclear glass. The activation energy was also determined by computing literature data. The results provide similar reactional mechanism for basaltic and nuclear glasses. Dissolution rates measured under saturation conditions were compared to theoretical dissolution rates. These ones were calculated using two kinetic models: the first rate equation is the Grambow's law which only takes into account ortho-silica acid activity; the second rate equation was proposed by Daux et al., where silica and aluminum are combined to formulate the affinity. The comparison between experimental and theoretical results point out that these two models are not appropriate to describe the alteration kinetic of basaltic glasses. (authors)

  7. 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%.

  8. 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

  9. Genetic aspects of basalts from the Carlsberg Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

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

  10. 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

  11. Sunset Crater, AZ: Evolution of a highly explosive basaltic eruption as indicated by granulometry and clast componentry

    Science.gov (United States)

    Allison, C. M.; Clarke, A. B.; Pioli, L.; Alfano, F.

    2011-12-01

    Basaltic scoria cone volcanoes are the most abundant volcanic edifice on Earth and occur in all tectonic settings. Basaltic magmas have lower viscosities, higher temperatures, and lower volatile contents than silicic magmas, and therefore generally have a lower potential for explosive activity. However, basaltic eruptions display great variability in eruptive style, from mild lava flows to more energetic explosions with large plumes. The San Francisco Volcanic Field (SFVF) in northern Arizona, active from 6 Ma-present, consists of over 600 volcanoes, mostly alkali basalt scoria cones, and five silicic centers [Wood and Kienle (1990), Cambridge University Press]. The eruption of Sunset Crater in the SFVF during the Holocene was an anomalously large basaltic explosive eruption, consisting of eight tephra-bearing phases and three lava flows [Amos (1986), MS thesis, ASU]. Typical scoria cone-forming eruptions have volumes sorted. Future work will include textural analysis of bubbles and crystals to understand the ascent and cooling history of the different clast types, and also to better interpret differences in abundance as related to variations in eruption or vent dynamics.

  12. 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)

  13. Geochemical characterization of oceanic basalts using artificial neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.

    method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). Artificial Neural Network (ANN) technique as a supervised Learning Vector Quantisation (LVQ) is applied to identify the inherent...

  14. Crystallization of oxidized, moderately hydrous arc basalt at mid-to-lower crustal pressures

    Science.gov (United States)

    Blatter, D. L.; Sisson, T. W.; Hankins, W. B.

    2012-12-01

    Decades of experimental work show that dry, reduced, subalkaline basalts differentiate to produce tholeiitic (high Fe/Mg) daughter liquids, however the influences of H2O and oxidation on differentiation paths are not well established. Accordingly, we performed crystallization experiments on a relatively magnesian basalt (8.7 wt% MgO) typical of mafic lavas erupted in the Cascades magmatic arc near Mount Rainier, Washington. Starting material was synthesized with 3 wt% H2O and run in 2.54 cm piston-cylinder vessels at 900, 700, and 400 MPa and 1200 to 925 degrees C. Samples were contained in Au75Pd25 capsules pre-saturated with Fe by reaction with magnetite at controlled fO2. Oxygen fugacity was controlled during high-pressure syntheses by the double capsule method using Re-ReO2 plus H2O-CO2 vapor in the outer capsule, mixed to match the expected fH2O of the vapor-undersaturated sample. Crystallization was similar at all pressures with a high temperature interval consisting of augite + olivine + orthopyroxene + Cr-spinel (in decreasing abundance). With decreasing temperature, plagioclase crystallizes, FeTi-oxides replace spinel, olivine dissolves, and finally amphibole appears. Liquids at 900 MPa track along Miyashiro's (1974) tholeiitic vs. calc-alkaline boundary, whereas those at 700 and 400 MPa become calc-alkaline by ~57 wt% SiO2 and greater. Although these evolved liquids are similar in most respects to common calc-alkaline andesites, they differ in having low-CaO due to early and abundant crystallization of augite prior to plagioclase, with the result that they become peraluminous (ASI: Al/(Na+K+Ca)>1) by ~55 wt% SiO2, similar to liquids reported in other studies of the high-pressure crystallization of hydrous basalts (Müntener and Ulmer, 2006 and references therein). A compilation of >7000 analyses of volcanic and intrusive rocks from the Cascades and the Sierra Nevada batholith shows that ASI in arc magmas increases continuously and linearly with SiO2 from

  15. 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.

  16. Gamma radiolysis effects on basalt groundwater

    International Nuclear Information System (INIS)

    Gray, W.J.

    1983-10-01

    Gamma radiolysis of basalt groundwater containing 700 ppM methane produces a milky liquid that is a suspension of fine particles of a high molecular weight hydrocarbon somewhat like polyethylene. The ability of these polymers to chelate with, or otherwise sorb, metal ions from aqueous solution was measured using Cu +2 as a representative cation. Values in the range 0.3 to 0.8 millimoles of Cu per liter of solution were found. 5 references, 2 figures, 2 tables

  17. Performance allocation traceable to regulatory criteria as applied to site characterization work at the Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    Deju, R.A.; Babad, H.; Bensky, M.S.; Jacobs, G.K.

    1983-01-01

    The Basalt Waste Isolation Project has developed a method for defining in detail the work required to demonstrate the feasibility of emplacing and providing for the safe isolation of nuclear wastes in a repository in the deep basalts at the Hanford Site near Richland, Washington. Criteria analysis allows the identification of areas of significant technical uncertainty or controversy that can be highlighted as issues. A preliminary analysis has been conducted, which, by identifying key radionuclides and allocating performance among the multiple barriers in a repository constructed in a basalt, allows the design and development testing activities at the Basalt Waste Isolation Project to be put into perspective. Application of sophisticated uncertainty analysis techniques will allow refinements in the analysis to be made and to further guide characterization and testing activities. Preliminary results suggest that a repository constructed in basalt will provide for the safe isolation of nuclear wastes in a cost-effective and reliable manner with a high degree of confidence

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

    DEFF Research Database (Denmark)

    Peate, David; Stecher, Ole

    2003-01-01

    We present new Pb isotope data on 21 samples of break-up-related flood basalts (56–54 Ma) from the Blosseville Kyst region of East Greenland. These samples show a considerable range in isotopic composition (206Pb/204Pb 17.6 to 19.3) that broadly correlates with compositional type. The ‘low-Ti’ type...... in the selected samples. Uncontaminated Palaeogene East Greenland flood basalts appear to have sampled the same broad range in mantle compositions seen in Recent Iceland basalts. In contrast to the peripheral lava suites from the British Isles and Southeast Greenland, where the inferred uncontaminated magmas have...... 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...

  19. Back-arc basin development: Constraints on geochronology and geochemistry of arc-like and OIB-like basalts in the Central Qilian block (Northwest China)

    Science.gov (United States)

    Gao, Zhong; Zhang, Hong-Fei; Yang, He; Pan, Fa-Bin; Luo, Bi-Ji; Guo, Liang; Xu, Wang-Chun; Tao, Lu; Zhang, Li-Qi; Wu, Jing

    2018-06-01

    The Lajishan belt of the Central Qilian block was a back-arc basin during Early Paleozoic. The basaltic magmatism and temporal evolution in this basin provide an opportunity to study the development of back-arc basin in an active continental margin. In this study, we carry out an integrated study of geochronological, geochemical and Sr-Nd isotopic compositions for the Early Paleozoic arc-like and OIB-like basalts. The Lajishan arc-like basalts are enriched in large ion lithophile element (LILE) and show negative Nb and Ta anomalies whereas the OIB-like basalts have high LILE abundances and show positive Nb and Ta anomalies. The arc-like basalts have initial 87Sr/86Sr values of 0.7050-0.7054 and εNd(t) values of +0.51-+2.63, and the OIB-like basalts have initial 87Sr/86Sr values of 0.7049-0.7050 and εNd(t) values of +0.66-+1.57. The geochemical and Sr-Nd isotopic compositions suggest that the arc-like basalts are derived from partial melting of a depleted mantle source metasomatized by slab-derived components at shallow depth levels, and the OIB-like basalts also originated from a metasomatized mantle wedge source. U-Pb zircon dating yielded the ages of 494 ± 4 Ma for the arc-like basalts and 468 ± 6 Ma for the OIB-like basalts. We argue that the arc-like basalts are products of back-arc extension before the back-arc rifting initiated in earlier stage, resulting from the northward subduction of the Qaidam-West Qinling oceanic slab, while the OIB-like basalts represent products of further back-arc spreading in response to rollback of the Qaidam-West Qinling oceanic lithospheric slab. The association of arc-like and OIB-like basalts in the Lajishan belt records the development of back-arc basin from initial rifting to subsequent spreading, offering insight into how basaltic magmatism generates in the formation of back-arc basin in subduction zone setting.

  20. 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

  1. Geology of the saucer-shaped sill near Mahad, western Deccan Traps, India, and its significance to the Flood Basalt Model

    Science.gov (United States)

    Duraiswami, Raymond A.; Shaikh, Tahira N.

    2013-07-01

    An ˜22-m-thick saucer-shaped sill occurs near Mahad and is exposed as a curvilinear, miniature ridge within the Deccan Traps. The sill has variable dips (42-55°). It has a 7.1-km long axis and 5.3 km short axis (aspect ratio of 1.4) and is larger than the MV sill of the Golden Valley sill complex, South Africa and the Panton sill, Australia. The sill has distinct glassy upper and lower chilled margins with a coarse-grained highly jointed core. The samples from the margin are invariably fractured and iron stained because of deuteric alteration. The rock from the sill is plagioclase-phyric basalt. At least three thick sill-like apophyses emanate from the base of the main sill. The apophyses change direction because of bending and thinning from a horizontal concordant sheet at the top to a discordant inclined form that bends again to pass into a lower horizontal concordant sheet. We interpret such features as `nascent saucer-shaped sills' that did not inflate to form nested sills. Geochemically, the sill consists of poorly differentiated tholeiitic basalt that has a restricted geochemical range. Critical trace element ratios and primitive mantle normalised trace and REE patterns indicate that the sills have geochemical affinities to the Poladpur chemical type and that the pahoehoe flow they intrude belongs to the Bushe Formation. Calculated magmatic overpressures during sill emplacement range from 8.4 to 11.3 MPa (for Young's modulus E = 5 GPa) and 16.7 to 22.5 MPa (for E=10 GPa) and depth to magma chamber ranges from 8.5 to 11.5 km ( E = 5 GPa) and 17.1 to 22.9 km ( E = 10 GPa), consistent with petrological and gravity modelling. The volume of the Mahad sill is approximately 276 km3 and is constant irrespective of the variations in the values of host-rock Young's modulus. In 1980, Cox (J Petrol 21:629-650, 1980) proposed a conceptual model of the crust-mantle section beneath the Karoo CFB which is considered as the fundamental model for flood basalt volcanism. Our

  2. 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.

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

    International Nuclear Information System (INIS)

    Smith, D.K.

    1990-01-01

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

  4. Effects of Elevated Temperature Treatment on Compositions and Tensile Properties of Several Kinds of Basalt Fibers

    Directory of Open Access Journals (Sweden)

    CHEN Jing

    2017-06-01

    Full Text Available Five kinds of domestic basalt fibers were studied for the changes of chemical compositions, physical properties and tensile properties of these fibers before and after 200-800℃ treatment in air atmosphere and in nitrogen atmosphere. These works were done mainly by means of X-ray fluorescence spectrometry and fiber monofilament tensile testing methods in order to understand the elevated temperature resistance of basalt fiber. The experimental results show that the surface of basalt fibers becomes smoother with slightly smaller in diameter and mass reduction at the same time, due to the removal of fiber surface treatment agent after elevated temperature treatment in air atmosphere. Mass fractions of SiO2 and Al2O3 decrease while mass fractions of FeO+Fe2O3, CaO and MgO increase, among which the mass fraction of FeO+Fe2O3 increase the most with the maximum increase of 21%. The monofilament tensile strength of basalt fiber is reduced after 200℃ treatment and the maximum strength retention percentage is 98.3%. The monofilament tensile strength reduces evidently after 400℃ treatment and the maximum strength retention percentage is 64.6%. Moreover, the strength retention percentages of five kinds of basalt fibers are all less than 20% after 800℃ treatment. In addition, the fiber elongation at break decreases with the increase of treating temperature and the elastic modulus increases. Compared with that in air atmosphere, strength retention rate of basalt fiber is higher and tensile properties are more stable in nitrogen atmosphere.

  5. Wear Characterization of Aluminium/Basalt Fiber Reinforced Metal Matrix Composites - A Novel Material

    Directory of Open Access Journals (Sweden)

    P. Amuthakkannan

    2017-06-01

    Full Text Available Aluminum alloy based metal matrix composite participate have a wider applications in wear resistance applications. Attempt made in current study is that, basalt fiber reinforced aluminum metal matrix composite have been prepared using stir casting method. Different weight percentage of basalt fiber reinforced with Al (6061 metal matrix composites are used to study the wear resistance of the composites. For wear study, percentage of reinforcement, normal load and sliding velocity are the considered as important parameters. To study the effect of basalt fiber reinforcement on the dry sliding wear of Al6061 alloy composites the Pin On wear tester is used. Initially hardness of the composites was tested, it was found that increasing reinforcement in the composite hardness value of the composites also increased. Based on the Grey relation analysis (GRA the effects of wear resistance of the composites were studied.

  6. Experimental Melting Study of Basalt-Peridotite Hybrid Source: Constrains on Chemistry of Recycled Component

    Science.gov (United States)

    Gao, S.; Takahashi, E.; Matsukage, K. N.; Suzuki, T.; Kimura, J. I.

    2015-12-01

    It is believed that magma genesis of OIB is largely influenced by recycled oceanic crust component involved in the mantle plume (e.g., Hauri et al., 1996; Takahashi & Nakajima., 2002; Sobolev et al., 2007). Mallik & Dasgupta (2012) reported that the wall-rock reaction in MORB-eclogite and peridotite layered experiments produced a spectrum of tholeiitic to alkalic melts. However, the proper eclogite source composition is still under dispute. In order to figure out the geochemistry of recycled component as well as their melting process, we conducted a series of high-P, high-T experiments. Melting experiments (1~10hrs) were performed under 2.9GPa with Boyd-England type piston-cylinder (1460~1540°C for dry experiments, 1400~1500°C for hydrous experiments) and 5GPa with Kawai-type multi-anvil (1550~1650°C for dry experiments, 1350~1550°C for hydrous experiments), at the Magma Factory, Tokyo Tech. Spinel lherzolite KLB-1 (Takahashi 1986) was employed as peridotite component. Two basalts were used as recycled component: Fe-enriched Columbia River basalt (CRB72-180, Takahashi et al., 1998) and N-type MORB (NAM-7, Yasuda et al., 1994). In dry experiments below peridotite dry solidus, melt compositions ranged from basaltic andesite to tholeiite. Opx reaction band generated between basalt and peridotite layer hindered chemical reaction. On the other hand, alkali basalt was formed in hydrous run products because H2O promoted melting process in both layers. Compared with melts formed by N-MORB-peridotite runs, those layered experiments with CRB are enriched in FeO, TiO2, K2O and light REE at given MgO. In other words, melts produced by CRB-peridotite layered experiments are close to alkali basalts in OIB and tholeiite in Hawaii, while those by layered experiments with N-MORB are poor in above elements. Thus we propose that Fe-rich Archean or Proterozoic tholeiite (BVSP 1980) would be a possible candidate for recycled component in OIB source.

  7. Emplacement of Columbia River flood basalt

    Science.gov (United States)

    Reidel, Stephen P.

    1998-11-01

    Evidence is examined for the emplacement of the Umatilla, Wilbur Creek, and the Asotin Members of Columbia River Basalt Group. These flows erupted in the eastern part of the Columbia Plateau during the waning phases of volcanism. The Umatilla Member consists of two flows in the Lewiston basin area and southwestern Columbia Plateau. These flows mixed to form one flow in the central Columbia Plateau. The composition of the younger flow is preserved in the center and the composition of the older flow is at the top and bottom. There is a complete gradation between the two. Flows of the Wilbur Creek and Asotin Members erupted individually in the eastern Columbia Plateau and also mixed together in the central Columbia Plateau. Comparison of the emplacement patterns to intraflow structures and textures of the flows suggests that very little time elapsed between eruptions. In addition, the amount of crust that formed on the earlier flows prior to mixing also suggests rapid emplacement. Calculations of volumetric flow rates through constrictions in channels suggest emplacement times of weeks to months under fast laminar flow for all three members. A new model for the emplacement of Columbia River Basalt Group flows is proposed that suggests rapid eruption and emplacement for the main part of the flow and slower emplacement along the margins as the of the flow margin expands.

  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. 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.

    -88)), diopside (Wo sub(45-51), En sub(25-37), Fs sub14-24)), and titanomagnetite (FeO sub(t) approx. 63.5 wt% and Ti0 sub(2) approx. 22.69 wt%). The whole-rock composition of these basalts has similar Mg [mole Mg/mole(Mg+Fe sup(2+))] (VT basalt: approx. 0...

  10. 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

  11. High-Mg basalts as a Signal of Magma System Replenishment at Lopevi Island, Vanuatu

    Science.gov (United States)

    Stewart, R. B.; Smith, I. E.; Turner, M. B.; Cronin, S. J.

    2007-05-01

    Lopevi is is a basalt to basaltic andesite island stratovolcano in central Vanuatu and is part of a long-lived, mature Island Arc chain. Central Vanuatu is tectonically influenced by the subduction of the D'Entrecasteaux zone. Primitive rock types that have been identified from the arc include picrites, ankaramites and high MgO basalts. High MgO rocks are generally considered to be a relatively rare component of arc-type magma suites but as detailed sequence sampling of individual volcanoes occurs, they have been identified more often. Here we report on the occurrence of high-Mg basalts in a sequence of lavas erupted in the last 100 years from Lopevi volcano. Activity at Lopevi is characteristically intermittent with eruptive sequences occurring over a c. 6 year period, separated by longer periods of repose. A major eruptive episode in 1939 caused evacuation of the island and the next eruptive episode in the 1960's also led to evacuation. The 1960's cycle of activity ended in 1982. The most recent phase of activity commenced in 1998 with a return to eruption of more siliceous, high alumina basaltic andesite. Geochemical data show that the 1960's lavas were different from those erupted earlier and later. They are olivine basalts with up to 9 wt percent MgO, 70 ppm Ni and 300 ppm Cr; Al2O3 content is about 12 wt percent. The 2003 lavas and pre-1960's lavas, in contrast, are basaltic andesites with c. 4 wt percent MgO, less than 25 ppm Ni, less than 100 ppm Cr and c. 20 wt percent Al2O3. The 1960's Lopevi sequence of eruptions represents an injection of a more primitive, high MgO magma at the end of a 21 year quiescent period after the major eruptions of 1939. Injection of small batches of more primitive magmas over decadal time periods at Lopevi marks the initiation of a new magmatic cycle. The occurrence of high MgO magmas as part of a cycle that includes typically low MgO arc type rocks demonstrates a consanguineous relationship and shows that high MgO arc type

  12. 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.

    was run through a computer programme of the least square and mass balance calculations for understanding the evolutionary path by differentiating minerals present in these basalts. The results indicate that the basalts under study represent a set...

  13. Enhancement of interfacial properties of basalt fiber reinforced nylon 6 matrix composites with silane coupling agents

    Directory of Open Access Journals (Sweden)

    2010-10-01

    Full Text Available In this work solution surface treatment was applied for producing basalt fiber reinforced PA6 matrix composites. Beyond scanning electron microscopy, static and dynamic mechanical tests, dynamic mechanical analysis of composites was used for qualifying the interfacial adhesion in a wide temperature range. The loss factor peak height of loss factor is particularly important, because it is in close relationship with the mobility of polymer molecular chain segments and side groups, hence it correlates with the number and strength of primary or secondary bondings established between the matrix and the basalt fibers. It was proven, that the interfacial adhesion between basalt fibers and polyamide can be largely improved by the application of silane coupling agents in the entire usage temperature range of composites. The presence of coupling agents on the surface of basalt fibers was proven by Fourier transform infrared spectroscopy. The best results were obtained by 3-glycidoxypropyltrimethoxysilane coupling agent.

  14. Low Velocity Impact Behavior of Basalt Fiber-Reinforced Polymer Composites

    Science.gov (United States)

    Shishevan, Farzin Azimpour; Akbulut, Hamid; Mohtadi-Bonab, M. A.

    2017-06-01

    In this research, we studied low velocity impact response of homogenous basalt fiber-reinforced polymer (BFRP) composites and then compared the impact key parameters with carbon fiber-reinforced polymer (CFRP) homogenous composites. BFRPs and CFRPs were fabricated by vacuum-assisted resin transfer molding (VARTM) method. Fabricated composites included 60% fiber and 40% epoxy matrix. Basalt and carbon fibers used as reinforcement materials were weaved in 2/2 twill textile tip in the structures of BFRP and CFRP composites. We also utilized the energy profile method to determine penetration and perforation threshold energies. The low velocity impact tests were carried out in 30, 60, 80, 100, 120 and 160 J energy magnitudes, and impact response of BFRPs was investigated by related force-deflection, force-time, deflection-time and absorbed energy-time graphics. The related impact key parameters such as maximum contact force, absorbed energy, deflection and duration time were compared with CFRPs for various impact energy levels. As a result, due to the higher toughness of basalt fibers, a better low velocity impact performance of BFRP than that of CFRP was observed. The effects of fabrication parameters, such as curing process, were studied on the low velocity impact behavior of BFRP. The results of tested new fabricated materials show that the change of fabrication process and curing conditions improves the impact behavior of BFRPs up to 13%.

  15. Release of Volatiles During North Atlantic Flood Basalt Volcanism and Correlation to the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Pedersen, J. M.; Tegner, C.; Kent, A. J.; Ulrich, T.

    2017-12-01

    The opening of the North Atlantic Ocean between Greenland and Norway during the lower Tertiary led to intense flood basalt volcanism and the emplacement of the North Atlantic Igneous Province (NAIP). The volcanism is temporally overlapping with the Paleocene-Eocene Thermal Maximum (PETM), but ash stratigraphy and geochronology suggests that the main flood basalt sequence in East Greenland postdates the PETM. Significant environmental changes during the PETM have been attributed to the release of CO2 or methane gas due to either extensive melting of hydrates at the ocean floor or as a consequence of the interaction of mantle derived magmas with carbon rich sediments.Estimates suggest that a minimum of 1.8x106 km3 of basaltic lava erupted during North Atlantic flood basalt volcanism. Based on measurements of melt inclusions from the flood basalts our preliminary calculations suggest that approximately 2300 Gt of SO2 and 600 Gt of HCl were released into the atmosphere. Calculated yearly fluxes approach 23 Mt/y SO2 and 6 Mt/y HCl. These estimates are regarded as conservative.The S released into to the atmosphere during flood basalt volcanism can form acid aerosols that absorb and reflect solar radiation, causing an effective cooling effect. The climatic effects of the release of Cl into the atmosphere are not well constrained, but may be an important factor for extinction scenarios due to destruction of the ozone layer.The climatic changes due to the release of S and Cl in these amounts, and for periods extending for hundred thousand of years, although not yet fully constrained are likely to be significant. One consequence of the North Atlantic flood basalt volcanism may have been the initiation of global cooling to end the PETM.

  16. The Cameroon line, West Africa, and its bearing on the origin of oceanic and continental alkali basalt

    International Nuclear Information System (INIS)

    Fitton, J.G.

    1985-01-01

    The Cameroon line is a unique within-plate volcanic province which straddles a continental margin. It consists of a chain of Tertiary to Recent, generally alkaline volcanoes stretching from the Atlantic island of Pagalu to the interior of the African continent. It provides, therefore, an ideal area in which to compare the sub-oceanic and sub-continental mantle sources for alkali basalt. Basaltic rocks in the oceanic and continental sectors are geochemically and isotopically indistinguishable which suggests that they have identical mantle sources. This conclusion rules out substantial lithosphere involvement in the generation of alkali basalts and therefore weakens the case for mantle metasomatism as a necessary precursor to alkaline magmatism. The convecting upper mantle is a much more likely source as it will be well-stirred and unlikely to show any ocean-continent differences. The long history of Cameroon line magmatism (65 Ma) and lack of evidence for migration of volcanism with time makes a deeper mantle source unlikely. Mid-ocean ridge basalts (MORB) also originate within the convecting upper mantle and so must share a common source with the Cameroon line alkali basalts (and, by implication, ocean island and continental rift basalts). A grossly homogeneous mantle with a bulk composition depleted in large-ion lithophile elements (LILE), but containing streaks of old, LILE-enriched material, provides a plausible common source. Large degree, near-surface melting of such a source would produce MORB. Smaller degree melts produced at deeper levels would percolate upwards along grain boundaries and become enriched in LILE by leaching LILE-rich grain boundary films. The mixing of these liquids with melts from the LILE-rich streaks will produce magmas with the geochemical and isotopic features of ocean island basalts. (orig.)

  17. 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.

  18. THE INFLUENCE OF THE FILLER GRAIN COMPOSITION ON THE PROPERTIES OF THE HEAT-RESISTANT BASALTIC CONCRETE

    Directory of Open Access Journals (Sweden)

    A. M. Gadzhiev

    2017-01-01

    Full Text Available Objectives. The optimal granulometric composition of filler compound ensures the production of concrete having improved  physical and mechanical characteristics, as well as minimal binder  consumption. The properties of heat-resistant concrete largely  depend on the type and the ratio of its components. Taking this into  account, the aim of the study is to determine the optimal grain composition of heat-resistant concrete.Methods. Methods for optimising the properties of heatresistant basaltic concrete with a composite binder and  mechanochemical activation of the filler grains were used during the  course of the research.A simplex-centroid experiment design is  applied for this purpose. The composite binder was subjected to  mechanochemical activation. Samples were made by vibration-pressing from a concrete mix with a cone draught of 2 cm.Results. The grain composition of heat-resistant concrete is proved  to be the most important variable factor, regulating which the  properties of concrete can be varied. The compositions of heat- resistant basaltic concrete with activated composite binder having a  maximum application temperature of 700 ºС are developed. The  influence of the grain composition of the basaltic filler on the  properties of basaltic concrete using mathematical experiment planning methods is determined. The regression equations for the ultimate tensile strength and bending stress of basaltic concrete are  obtained for heating temperature of 700ºC.Conclusion. The granulometric composition of heat-resistant basaltic concrete based on the activated binder is optimised for basic physical and technical properties. The optimal granulometric  design of the composition of heat-resistant concrete indicates that as the coarse fraction (particles greater than 0.63 mm in the filler  composition increases, the ultimate tensile strength and bending  stress of heatresistant basaltic concrete is increased

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

    DEFF Research Database (Denmark)

    Søager, Nina

    primitive basalts and trachybasalts but also more evolved samples from the retroarc region and the larger volcanoes Payún Matrú and Payún Liso are presented. The samples cover a broad range of compositions from intraplate lavas similar to ocean island basalts to arc andesites. A common feature found...... 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...... the lithosphere is thinnest and possibly in areas of elevated mantle temperatures. The pyroxenite melts formed at deeper levels react with the surrounding peridotite and thereby changes composition leading to eruption of melts which experienced variable degrees of melt-peridotite interaction. This can presumably...

  20. Nano-scale observations of interface between lichen and basaltic rock: Pseudomorphic growth of amorphous silica on augite

    Science.gov (United States)

    Tamura, T.; Kyono, A.; Kebukawa, Y.; Takagi, S.

    2017-12-01

    Recently, lichens as the earliest colonizers of terrestrial habitats are recognized to accelerate the mineral degradation at the interface between lichens and surface rocks. Much interest has been therefore devoted in recent years to the weathering induced by the lichen colonization. Here, we report nano-scale observations of the interface between lichens and basaltic rock by TEM and STXM techniques. Some samples of basaltic rocks totally covered by lichens were collected from the 1986 lava flows on the northwest part of Izu-Oshima volcano, Japan. To prepare specimens for the nano-scale observation, we utilized the focused ion beam (FIB) system. The microstructure and local chemistry of the specimens were thoroughly investigated by TEM equipped with energy-dispersive X-ray spectroscopy (EDX). Chemical components and chemical heterogeneity at the interface were observed by scanning transmission X-ray microscopy (STXM) at Advanced Light Source branch line 5.3.2.2. The collected rocks were classified into the augite-pigeonite-bronzite basalt including 6 to 8% plagioclase phenocrysts. The lichens adhering to the rocks were mainly Stereocaulon vesuvianum, fruticose lichen, which are widespread over the study area. The metabolites of the Stereocaulon vesuvianum exhibited a mean pH of 4.5 and dominance by acids. The STEM-EDX observations revealed that the interface between augite and the lichen was completely covered with amorphous silica multilayer with a thickness of less than 1 µm. Ca L-edge XANES spectra of the augite showed that the energy profile of the absorption edge at 349 eV was varied with the depth from the surface, indicating that the M2 site coordination accommodating Ca2+ undergoes significant change in shape as a function of distance from the surface. This behavior results from the fact that the M2 site is more distorted and more flexible in the C2/c clinopyroxene phase. Taking into consideration that the S. vesuvianum can produce acidic organic compounds

  1. Review on effect of chemical, thermal, additive treatment on mechanical properties of basalt fiber and their composites

    Science.gov (United States)

    Jain, Naman; Singh, Vinay Kumar; Chauhan, Sakshi

    2017-12-01

    Basalt fiber is emerging out the new reinforcing material for composites. To overcome some of the disadvantages of fibers such as poor bonding to polymers, low thermal stability and high moisture absorption fiber characteristics are modified with chemical, thermal and additive treatments. Chemical treatment corrosive resistance to alkali and acid were investigated which were used to clean and modify the surface of fiber for higher bonding with resins. To improve the thermal stability and reduce moisture uptake thermal treatment such as plasma and non thermal plasma were used which increased the surface roughness and change the chemical composition of surface of basalt fiber. Additive treatment is used to improve the mechanical properties of fibers, in basalt fiber additive treatment was done with SiO2 additive because of its chemical composition which contains major content of SiO2. In present investigation review on the effect of different treatment such as chemical, thermal and additive were studied. Effect of these treatment on chemical composition of the surface of basalt fiber and corrosion to acidic and alkali solution were studied with their effect on mechanical properties of basalt fiber and their composite.

  2. Material toughness, internal structure, and caldera-collapse frequencies in basaltic and composite edifices

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, Agust [Department of Earth Sciences, Queen' s Building, Royal Holloway University of London, Egham TW20 OEX (United Kingdom)], E-mail: a.gudmundsson@es.rhul.ac.uk

    2008-10-01

    Formation of, and slip on existing, collapse calderas is much more common in basaltic edifices than in composite edifices. I suggest that this difference is partly due to the composite edifices being tougher and more resistant to ring-fault formation than a basaltic edifices. The high matieral toughness of composite edifices is related to their being composed of rock layers with widely different elastic properties, the elastic mismatch promoting deflection and/or arrest of potential ring faults at layer contacts.

  3. 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.

  4. Effect of γ irradiation on the properties of basalt fiber reinforced epoxy resin matrix composite

    International Nuclear Information System (INIS)

    Li, Ran; Gu, Yizhuo; Yang, Zhongjia; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2015-01-01

    Gamma-ray (γ-ray) irradiation is a crucial reason for the aging in materials used for nuclear industry. Due to high specific strength and stiffness, light weight and good corrosion resistance, fiber reinforced composites are regarded as an alternative of traditional materials used on nuclear facilities. In this study, basalt fiber (BF)/AG80 epoxy composite laminates were fabricated by autoclave process and treated with "6"0Co gamma irradiation dose up to 2.0 MGy. Irradiation induced polymer chain scission and oxidation of AG80 resin were detected from physical and chemical analysis. The experimental results show that the tensile and flexural performances of irradiated BF/AG80 composite maintain stable and have a low amplitude attenuation respectively, and the interlaminar shear strength has increased from irradiation dose of 0–1.5 MGy. Furthermore, the comparison between the studied BF composite and reported polymer and composite materials was done for evaluating the γ resistance property of BF composite. - Highlights: • The properties of basalt fiber reinforced epoxy resin matrix composite under "6"0Co γ irradiation up to 2.0 MGy were studied. • Basalt fiber can weaken the aging effects of γ irradiation on the resin matrix. • Tensile property of basalt fiber composite remains stable and flexural property has a low degree of attenuation. • Basalt fiber composite is an ideal candidate of structural material for nuclear industry.

  5. 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

  6. 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.

  7. Contemporaneous alkaline and calc-alkaline series in Central Anatolia (Turkey): Spatio-temporal evolution of a post-collisional Quaternary basaltic volcanism

    Science.gov (United States)

    Dogan-Kulahci, Gullu Deniz; Temel, Abidin; Gourgaud, Alain; Varol, Elif; Guillou, Hervé; Deniel, Catherine

    2018-05-01

    This study focuses on spatio-temporal evolution of basaltic volcanism in the Central Anatolian post-collisional Quaternary magmatic province which developed along a NE-SW orientation in Turkey. This magmatic province consists of the stratovolcanoes Erciyes (ES) and Hasandag (HS), and the basaltic volcanic fields of Obruk-Zengen (OZ) and Karapınar (KA). The investigated samples range between basic to intermediate in composition (48-56 wt% SiO2), and exhibit calc-alkaline affinity at ES whereas HS, OZ and KA are alkaline in composition. Based on new Ksbnd Ar ages and major element data, the oldest basaltic rock of ES is 1700 ± 40 ka old and exhibits alkaline character, whereas the youngest basaltic trachyandesite is 12 ± 5 ka old and calc-alkaline in composition. Most ES basaltic rocks are younger than 350 ka. All samples dated from HS are alkaline basalts, ranging from 543 ± 12 ka to 2 ± 7 ka old. With the exception of one basalt, all HS basalts are 100 ka or younger in age. Ksbnd Ar ages range from 797 ± 20 ka to 66 ± 7 ka from OZ. All the basalt samples are alkaline in character and are older than the HS alkaline basalts, with the exception of the youngest samples. The oldest and youngest basaltic samples from KA are 280 ± 7 ka and 163 ± 10 ka, respectively, and are calc-alkaline in character. Based on thermobarometric estimates samples from OZ exhibit the highest cpx-liqidus temperature and pressure. For all centers the calculated crystallization depths are between 11 and 28 km and increase from NE to SW. Multistage crystallization in magma chamber(s) located at different depths can explain this range in pressure. Harker variation diagrams coupled with least-squares mass balance calculations support fractional crystallization for ES and, to lesser extend for HS, OZ and KA. All basaltic volcanic rocks of this study are enriched in large-ion lithophile elements (LILE) and light rare earth elements (LREE). The lack of negative anomalies for high field

  8. Near field chemical speciation: the reaction of uranium and thorium with Hanford basalt and elevated pH

    International Nuclear Information System (INIS)

    Perry, D.L.

    1984-01-01

    The hydrolysis of radionuclides such as thorium and uranium and their subsequent chemisorption on Hanford basalt have been studied using a variety of techniques, including x-ray photoelectron and infrared spectroscopy. Data obtained to date indicate mixed complexes of uranium and thorium to be on the basalt surface, the complexes being radionuclide oxides, hydrated oxides (hydroxides), and carbonates. These findings are discussed with respect to their importance for input for models describing speciation and dissolution processes involving nuclear waste repository materials such as Hanford basalt. 5 figures, 2 tables

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

    International Nuclear Information System (INIS)

    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

  10. High water contents in basaltic melt inclusions from Arenal volcano, Costa Rica

    Science.gov (United States)

    Wade, J. A.; Plank, T.; Hauri, E. H.; Melson, W. G.; Soto, G. J.

    2004-12-01

    Despite the importance of water to arc magma genesis, fractionation and eruption, few quantitative constraints exist on the water content of Arenal magmas. Early estimates, by electron microprobe sum deficit, suggested up to 4 wt% H2O in olivine-hosted basaltic andesite melt inclusions (MI) from pre-historic ET-6 tephra (Melson, 1982), and up to 7 wt% H2O in plagioclase and orthopyroxene-hosted dacitic MI from 1968 lapilli (Anderson, 1979). These high water contents are consistent with abundant hornblende phenocrysts in Arenal volcanics, but inconsistent with geochemical tracers such as 10Be and Ba/La that suggest a low flux of recycled material (and presumably water) from the subduction zone. In order to test these ideas, and provide the first direct measurements of water in mafic Arenal magmas, we have studied olivine-hosted MI from the prehistoric (900 yBP; Soto et al., 1998) ET3 tephra layer. MI range from andesitic (> 58% SiO2) to basaltic compositions ( 4 wt%) found here for Arenal basaltic MI support the semi-quantitative data from earlier studies, but are somewhat unexpected given predictions from slab tracers. Arenal water contents (4%) approach those of the 1995 eruption of Cerro Negro in Nicaragua (4-5 wt% in basaltic MI; Roggensack et al., 1997), despite the fact that the latter has Ba/La of > 100, while Arenal has Ba/La Journal of Geology; Melson, William G. (1982) Boletin de Volcanologia; Roggensack et al. (1997) Science; Soto et al. (1998) OSIVAM; Williams-Jones et al. (2001) Journal of Volc. and Geoth. Res.

  11. Mechanical and thermal properties of basalt fiber reinforced poly(butylene succinate) composites

    International Nuclear Information System (INIS)

    Zhang Yihe; Yu Chunxiao; Chu, Paul K.; Lv Fengzhu; Zhang Changan; Ji Junhui; Zhang Rui; Wang Heli

    2012-01-01

    Highlights: ► Novel basalt fiber-reinforced biodegradable poly(butylene succinate) composites have been successfully fabricated with various fiber loadings. ► The tensile and flexural properties of the PBS matrix resin are improved significantly by increasing the fiber loading in the composites. ► The impact strength of the BF/PBS composite decreases with the addition fibers primarily and increases with increasing fiber loading due to energy dissipation when the fibers are pulled out. ► Heat deflection temperature tests clearly show that the HDT of the basalt fiber reinforced PBS composites is significantly higher than the HDT of the PBS resin. - Abstract: Basalt fiber (BF) reinforced poly(butylene succinate) (PBS) composites have been fabricated with different fiber contents by a injection molding method and their tensile, flexural and impact properties, as well as thermal stability have been investigated. The tensile and flexural properties of the PBS matrix resin are improved markedly by increasing the fiber contents in the composites. The values are relatively higher than the natural fiber/PP systems reported earlier by other research groups. The heat deflection temperature (HDT) and Vicat softening temperature (VST) of the composites are significantly higher than those of the neat PBS resin. Scanning electron microscopy (SEM) conducted on the fracture surfaces of the composites reveals superior interfacial linkage between the basalt fibers and PBS matrix. The results suggest that the BF/PBS composites may be a potential candidate of PP or PP composites to manufacturing some daily commodities to solve the “white pollution” in environmental management.

  12. 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

  13. 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.

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

    Science.gov (United States)

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

    2001-03-09

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

  15. Markers of the pyroxenite contribution in the major-element compositions of oceanic basalts: Review of the experimental constraints

    Science.gov (United States)

    Lambart, Sarah; Laporte, Didier; Schiano, Pierre

    2013-02-01

    Based on previous and new results on partial melting experiments of pyroxenites at high pressure, we attempt to identify the major element signature of pyroxenite partial melts and to evaluate to what extent this signature can be transmitted to the basalts erupted at oceanic islands and mid-ocean ridges. Although peridotite is the dominant source lithology in the Earth's upper mantle, the ubiquity of pyroxenites in mantle xenoliths and in ultramafic massifs, and the isotopic and trace elements variability of oceanic basalts suggest that these lithologies could significantly contribute to the generation of basaltic magmas. The question is how and to what degree the melting of pyroxenites can impact the major-element composition of oceanic basalts. The review of experimental phase equilibria of pyroxenites shows that the thermal divide, defined by the aluminous pyroxene plane, separates silica-excess pyroxenites (SE pyroxenites) on the right side and silica-deficient pyroxenites (SD pyroxenites) on the left side. It therefore controls the melting phase relations of pyroxenites at high pressure but, the pressure at which the thermal divide becomes effective, depends on the bulk composition; partial melt compositions of pyroxenites are strongly influenced by non-CMAS elements (especially FeO, TiO2, Na2O and K2O) and show a progressive transition from the liquids derived from the most silica-deficient compositions to those derived from the most silica-excess compositions. Another important aspect for the identification of source lithology is that, at identical pressure and temperature conditions, many pyroxenites produce melts that are quite similar to peridotite-derived melts, making the determination of the presence of pyroxenite in the source regions of oceanic basalts difficult; only pyroxenites able to produce melts with low SiO2 and high FeO contents can be identified on the basis of the major-element compositions of basalts. In the case of oceanic island basalts

  16. Evaluation of basalt flows as a waste isolation media

    International Nuclear Information System (INIS)

    Deju, R.A.

    1978-01-01

    Activities in basalt waste isolation programs in the Columbia River basin are reported. Work during the period is summarized for the overall program which is divided into systems integration, geology, hydrology, engineered barriers studies, engineering testing, and the construction of a near-surface test facility

  17. Petrography and chemistry of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    interior through a variolitic zone. The silica-alkalies relation show these basalts to be of sub-alkaline nature. Variable normative compositions and Mg number, increase in alkali index, differences in Al2O3/CaO and FeO/MgO ratios, variable trace element...

  18. 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

  19. 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

  20. 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.

  1. Geochemistry of the earth mantle: distribution of trace elements in the basaltic magma Pt. 1

    International Nuclear Information System (INIS)

    Joron, J.-L.; Jaffrezic, H.; Treuil, M.

    1982-01-01

    A method for the study of petrogenetic processes by geochemical reasoning based on the chemical analysis of ''hygromagmaphil'' elements in rock suites has recently been applied in our laboratory to suites of oceanic basalts sampled during the I.P.O.P. (International Program for Ocean Drilling) program and several French missions in the North Atlantic (FAMOUS-VEMA-MAPCO). The main conclusions derived from this extensive data are as follows. We confirm that magma sources for the oceanic basalts are to be found in two distinctive mantle domains. To the large scale heterogeneity a smaller scale complex one is superimposed. Intermediate mantle source characteristics may also be found. Mantle source zonation is, at least in part, an old feature as borne out by off ridge metamorphosed basalts. (author)

  2. 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.

  3. 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.

  4. 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.

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

    Science.gov (United States)

    Nerilli, Francesca; Vairo, Giuseppe

    2016-06-01

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

  6. The Archaen volcanic facies in the Migori segment, Nyanza greenstone belt, Kenya: stratigraphy, geochemistry and mineralisation

    Science.gov (United States)

    Ichang'l, D. W.; MacLean, W. H.

    The Migori segment is an 80 by 20 km portion of the Nyanza greenstone belt which forms the northern part of the Archean Tanzanian Craton in western Kenya, northern Tanzania and southeastern Uganda. It consists of two volcanic centres, each with central, proximal and distal volcanic facies, comprising the Migori Group, the Macalder and Lolgorien Subgroups, and eleven volcano-sedimentary formations. The centres are separated by a basin of tuffs and greywacke turbidites. The volcanics are bimodal mafic basalt and dolerite ( Zr/Y = 3.8 - 6.5, La N/Yb N = 1.0 - 2.4) , and felsic calc-alkaline dacite-rhyolite ( Zr/Y = 10 - 21, La N/Yb N = 19 - 42 ) and high-K dacite ( Zr/Y = 9 - 16, La N/Yb N = 21 - 22 ). Felsic units form approximately three-fourths of the volcanic stratigraphy. Basalts, calc-alkaline dacites and rhyolites were deposited in a submarine environment, but the voluminous high-K dacites were erupted subaerially. The turbidites contain units of iron-formations. Granitic intrusions are chemically continuous with the high-K dacites. The felsic volcanics are anologous to those found at modern volcanic arc subduction settings involving continental crust. The Macalder ZnCuAuAg volcanogenic massive sulphide deposits is in central facies basalts-greywacke-rhyolite. Gold mineralisation occurs in proximal facies tuffs and iron formation, and in oblique and semi-conformable quartz veins. Greenstones in the Nyanza belt are dominated by calc-alkaline felsic volcanics in constrast to the komatiite-tholeiitic basalt volcanism in the Kaapvaal Craton of South Africa, and a mixture of the two types in the Zimbabwe Craton.

  7. 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

  8. 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.

  9. Effect of Elevated Temperature on the Residual Properties of Quartzite, Granite and Basalt Aggregate Concrete

    Science.gov (United States)

    Masood, A.; Shariq, M.; Alam, M. Masroor; Ahmad, T.; Beg, A.

    2018-05-01

    In the present study, experimental investigations have been carried out to determine the effect of elevated temperature on the residual properties of quartzite, granite and basalt aggregate concrete mixes. Ultrasonic pulse velocity and unstressed residual compressive strength tests on cube specimens have been conducted at ambient and after single heating-cooling cycle of elevated temperature ranging from 200 to 600 °C. The relationship between ultrasonic pulse velocity and residual compressive strength of all concrete mixes have been developed. Scanning electron microscopy was also carried out to study micro structure of quartzite, granite and basalt aggregate concrete subjected to single heating-cooling cycle of elevated temperature. The results show that the residual compressive strength of quartzite aggregate concrete has been found higher than granite and basalt aggregate concrete at ambient and at all temperatures. It has also been found that the loss of strength in concrete is due to the development of micro-cracks result in failure of cement matrix and coarse aggregate bond. Further, the basalt aggregate concrete has been observed lower strength due to low affinity with Portland cements ascribed to its ferro-magnesium rich mineral composition.

  10. 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.

  11. Mantle and crustal contribution in the genesis of Recent basalts from off-rift zones in Iceland: Constraints from Th, Sr and O isotopes

    Science.gov (United States)

    Sigmarsson, Olgeir; Condomines, Michel; Fourcade, Serge

    1992-05-01

    Along the two volcanic off-rift zones in Iceland, the Sn˦fellsnes volcanic zone (SNVZ) and the South Iceland volcanic zone (SIVZ), geochemical parameters vary regularly along the strike towards the centre of the island. Recent basalts from the SNVZ change from alkali basalts to tholeiites where the volcanic zone reaches the active rift axis, and their 87Sr/ 86Sr and Th/U ratios decrease in the same direction. These variations are interpreted as the result of mixing between mantle melts from two distinct reservoirs below Sn˦fellsnes. The mantle melt would be more depleted in incompatible elements, but with a higher 3He/ 4He ratio ( R/Ra≈ 20) beneath the centre of Iceland than at the tip of the Sn˦fellsnes volcanic zone ( R/Ra≈ 7.5). From southwest to northeast along the SIVZ, the basalts change from alkali basalts to FeTi basalts and quartz-normative tholeiites. The Th/U ratio of the Recent basalts increases and both ( 230Th/ 232Th ) and δ 18O values decrease in the same direction. This reflects an important crustal contamination of the FeTi-rich basalts and the quartz tholeiites. The two types of basalts could be produced through assimilation and fractional crystallization in which primary alkali basaltic and olivine tholeiitic melts 'erode' and assimilate the base of the crust. The increasingly tholeiitic character of the basalts towards the centre of Iceland, which reflects a higher degree of partial melting, is qualitatively consistent with increasing geothermal gradient and negative gravity anomaly. The highest Sr isotope ratio in Recent basalts from Iceland is observed inÖr˦fajökull volcano, which has a 3He/ 4He ratio ( R/Ra≈ 7.8) close to the MORB value, and this might represent a mantle source similar to that of Mauna Loa in Hawaii.

  12. 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)

  13. 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.

  14. Studying the ability to use basalt in preparing radiation shielding concrete and the properties of the resulted concrete

    International Nuclear Information System (INIS)

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

    2010-12-01

    Basalt is widespread rocks in the lands of Syria. This kind of rocks has high density relatively, high insulation properties and, mechanical and heat resistance. In this work several kinds of basalt rocks, which were collected from several sites, were studied. The analyses which were done, shows that the basalt rocks collected from Shahba, Nba'a Al-Sakhr and Almana'a mountain are suitable for high efficient gamma radiation shielding, but with low efficiency for neutron shielding, especially for thermal and epithermal neutrons. (author)

  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. Technical program plan, Basalt Waste Isolation Project

    International Nuclear Information System (INIS)

    1979-12-01

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

  17. 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...

  18. 40Ar-39Ar age determinations on the Owyhee basalt of the Columbia plateau

    International Nuclear Information System (INIS)

    Bottomley, R.J.; York, D.

    1976-01-01

    40 Ar/ 39 Ar step-heating analyses have been performed on 11 samples of basalt from sites near Owyhee Reservoir of southeastern Oregon, U.S.A. These rocks were extruded during the great flood basalt episode of the Pacific Northwest. The whole-rock points are highly correlated on a plot of 40 Ar/ 36 Ar versus 39 Ar/ 36 Ar, corresponding to a common age of the samples of 14.3+-0.3 m.y. Inspite of this, individual 'plateau' plots of the age versus fraction of 39 Ar released do not give good plateaux. These age spectra exhibit to varying degrees a common structure in which lower age values are found at higher temperatures. This pattern may result from a closed-system redistribution of the argon isotopes. The usefulness of grinding the basalts in removing a loosely held atmospheric argon component is confirmed. (Auth.)

  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. 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.

  2. Migration of Amphitheater-Headed Valleys in Kauai Basalts: Wailua Falls as a Case Example

    Science.gov (United States)

    Pederson, D. T.; Blay, C.

    2006-12-01

    Amphitheater-headed valleys in Kauai basalts migrate upstream primarily because of weathering processes. Basalt weathering rates are enhanced by the presence of water and/or vegetation. When both weathering process are present, weathering rates are greater than the sum of the two processes. Because waterfalls can create an environment where vegetation growth is greatly inhibited by the impact of falling water, weathering rates may be much greater on each side of the falls where vegetation can grow. Sources of water for weathering include groundwater discharge, waterfall spray, and condensation of atmospheric water. Because basalts weather rapidly in tropical environments, streams require only the capability to transport smaller particle sizes to sustain amphitheater migration. It should be noted that most waterfalls occupy only a small fraction of the amphitheater head which further supports weathering as the principal agent in amphitheater development and migration. Lava flows building shield volcanos are usually episodic with crystallization and possible weathering occurring before the next flow. The rate of cooling of a flow determines the crystal size of minerals and in combination with the magma chemistry the susceptibility of a flow to weathering process as well as the strength of the rock. With time, soils and topography will develop on the now crystallized flow. Because clays are a product of basalt weathering, soils when buried by later flows, represent low permeability layers. Additionally, new flows may follow (and bury) surface drainage systems resulting in localized thicker flows that cool more slowly and have different properties then the adjacent thinner flows. Consequently, most amphitheater heads have significant heterogenieties, especially in a vertical section representing multiple basalt flows. Wailua Falls on Kauai will be used as a field example of amphitheater weathering processes and migration.

  3. Impact of urbanization coupled with drought situations on groundwater quality in shallow (basalt) and deeper (granite) aquifers with special reference to fluoride in Nanded-Waghala Municipal Corporation, Nanded District, Maharashtra (India).

    Science.gov (United States)

    Pandith, Madhnure; Kaplay, R D; Potdar, S S; Sangnor, H; Rao, A D

    2017-09-01

    Rapid expansion in urbanization and industrialization coupled with recent drought conditions has triggered unplanned groundwater development leading to severe stress on groundwater resources in many urban cities of India, particularly cities like Nanded, Maharashtra. In the quest of tapping drinking water requirement, due to recent drought conditions, people from the city are piercing through entire thickness of shallow basalt aquifers to reach productive deeper granite aquifers. Earlier reports from Nanded and surrounding districts suggest that deeper granite aquifer is contaminated with fluoride (geogenic). The study aimed to find out variations in fluoride concentration in shallow basalt (10-167 m) and deeper granite aquifers (below 167 m) and to find out the relationship between fluoride and other ions. Study suggests that concentration of fluoride in shallow basalt aquifer is within maximum permissible limits of Bureau of Indian Standards and deeper granite aquifer contains as high as 4.9 mg/l of fluoride and all samples from granite aquifers are unfit for human consumption. The groundwater from basalt aquifer is mainly Ca-HCO 3- Cl type, and from granite aquifer, it is Ca-Na-Cl type. The correlation plot between F - vs. pH, Na + and HCO 3 - shows a positive correlation and an inverse relationship with Ca 2+ in both aquifers. As recommendations, it is suggested that granite aquifers should not be tapped for drinking purposes; however, in drought situations, water from this aquifer should be blended with treated surface water before supplying for drinking purposes. Efforts may be made to utilize 1.35 MCM of rainwater from available rooftop, which is sufficient to cater for the needs of ~40,800 people annually. Most effective defluoridation techniques like electrolytic de-fluoridation (EDF), ion exchange and reverse osmosis may be adopted along with integrated fluorosis mitigation measures.

  4. Identification of Columbia River basalt flows from deep cores in the Pasco Basin based on trace element abundances

    International Nuclear Information System (INIS)

    Fruchter, J.S.; Rancitelli, L.A.

    1976-01-01

    Samples of basalt from three deep core holes drilled in the Pasco Basin, Washington (DDH-3, DH-4, DH-5) were analyzed by instrumental neutron activation (INAA) for up to fifteen trace and major elements. These analyses were used to assign each basalt flow to one of a series of previously defined chemical types of the Columbia River Basalt Group. All of the flows except the two flows at the bottom of well DDH-3 were clearly assignable to one of the defined chemical types. These two flows apparently represent new, as yet undefined chemical types. Average values and standard deviations for compositions of each of the chemical types found in the three wells are presented along with two-element variation diagrams for the geochemically important pair La-Cr, La-Fe, La-Th and La-Sc. The assignment of the flows to known chemical types accomplished in this study was very helpful in relating the basalts in the core holes to stratigraphically defined basalt flows in surface sections. A correlation diagram relating the flows in the core holes to one another on the basis of chemical type is presented

  5. 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

  6. 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.

    Rocks dredged in the vicinity of the 79 degrees E fracture zone, in the Central Indian Basin, are sub-alkaline basalts, which are regarded as precursors to spilites. The minerals identified are mainly albitic plagioclase, augite, olivine, and less...

  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. 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

  9. One-year follow-up of the phagocytic activity of leukocytes after exposure of rats to asbestos and basalt fibers.

    Science.gov (United States)

    Hurbánková, M

    1994-01-01

    The phagocytic activity of leukocytes in peripheral blood was investigated after 2, 24, and 48 hr; 1, 2, 4, and 8 weeks; and 6 and 12 months following intraperitoneal administration of asbestos and basalt fibers to Wistar rats. Asbestos and basalt fibers differed in their effects on the parameters studied. Both granulocyte count and phagocytic activity of leukocytes during the 1-year dynamic follow-up in both dust-exposed groups of animals changed in two phases, characterized by the initial stimulation of the acute phase I, followed by the suppression of the parameters in the chronic phase II. Exposure to asbestos and basalt fibers led, in phase II, to impairment of the phagocytic activity of granulocytes. Asbestos fibers also significantly decreased phagocytic activity of monocytes. Exposure to basalt fibers did not affect the phagocytic activity of monocytes in phase II. Results suggest that the monocytic component of leukocytes plays an important role in the development of diseases caused by exposure to fibrous dusts, but basalt fibers have lesser biological effects than asbestos fibers. PMID:7882931

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

    African Journals Online (AJOL)

    Al2O3), and Al-rich spinel occur in alkali basalts from Liri, South of the ... these spinel lherzolite xenoliths are reported, along with the analyses of ...... erupted in the Liri region. .... and temperatures with controlled activities of water, carbon.

  11. A study of the thermostimulated evolution of labelled hydrogen sulfide from the leached basalt fibers

    International Nuclear Information System (INIS)

    Zheleznov, A.V.; Zyuzin, A.Yu.; Bekman, I.N.

    1991-01-01

    Thermostimulated separation of labelled hydrogen sulfide from basalt fibers leached by hydrochloric acid is investigated by the method of radioactive tracers. It is shown that the type of H 2 35 S thermosorption spectrum depends on the presence of water traces in a fibrous adsrobent. Formal order and activation energy of thermodesorption of labelled hydrogen sulfide as well as inhomogeneity of porous structure of adsorbents based on basalt fibers are established

  12. 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.)

  13. Effect of Thermal Cycling on the Tensile Behavior of Polymer Composites Reinforced by Basalt and Carbon Fibers

    Science.gov (United States)

    Khalili, S. Mohammad Reza; Najafi, Moslem; Eslami-Farsani, Reza

    2017-01-01

    The aim of the present work was to investigate the effect of thermal cycling on the tensile behavior of three types of polymer-matrix composites — a phenolic resin reinforced with woven basalt fibers, woven carbon fibers, and hybrid basalt and carbon fibers — in an ambient environment. For this purpose, tensile tests were performed on specimens previously subjected to a certain number of thermal cycles. The ultimate tensile strength of the specimen reinforced with woven basalt fibers had by 5% after thermal cycling, but the strength of the specimen with woven carbon fibers had reduced to a value by 11% higher than that before thermal cycling.

  14. Petrogenesis of Neogene basaltic volcanism associated with the Lut block, eastern Iran: Implication for tectonic and metallogenic evolution

    Science.gov (United States)

    Saadat, Saeed

    This dissertation presents petrochemical data concerning Neogene olivine basalts erupted both along the margins and within the micro-continental Lut block, eastern Iran, which is a part of the active Alpine-Himalayan orogenic belt. These data demonstrate the following: (1) Basalts that erupted from small monogenetic parasitic cones around the Bazman stratovolcano, Makran arc area, in the southern Lut block, are low-Ti sub-alkaline olivine basalts. Enrichments of LILE relative to LREE, and depletions in Nb and Ta relatively to LILE, are similar to those observed for other convergent plate boundary arc magmas around the world and suggest that these basalts formed by melting of subcontinental mantle modified by dehydration of the subducted Oman Sea oceanic lithosphere. (2) Northeast of Iran, an isolated outcrop of Neogene/Quaternary alkali olivine basalt, containing mantle and crustal xenoliths, formed by mixing of small melt fractions from both garnet and spinel-facies mantle. These melts rose to the surface along localized pathways associated with extension at the junction between the N-S right-lateral strike-slip faults and E-W left-lateral strike slip faults. The spinel-peridotite mantle xenoliths contained in the basalts, which equilibrated in the subcontinental lithosphere at depths of 30 to 60 km and temperatures of 965°C to 1065°C, do not preserve evidence of extensive metasomatic enrichment as has been inferred for the mantle below the Damavand volcano further to the west in north-central Iran. (3) Neogene mafic rocks within the central Lut block represent the last manifestation of a much more extensive mid-Tertiary magmatic event. These basalts formed from both OIB-like asthenosphere and subcontinental lithosphere which preserved chemical characteristics inherited from mid-Tertiary subduction associated with the collision of the Arabian with the Eurasian plate and closing of the Neotethys Ocean. Neogene/Quternary alkali olivine basalts erupted mainly along

  15. Isotopic composition of strontium in three basalt-andesite centers along the Lesser Antilles arc

    Science.gov (United States)

    Hedge, C.E.; Lewis, J.F.

    1971-01-01

    Si87/Sr86 ratios have been determined for lavas and py lastic rocks from three basalt-andesite centers along the Lesser Antilles arc-Mt. Misery on the island of St. Kitts, Soufriere on the island of St. Vincent, and Carriacou, an island of The Grenadines. The average Si87/Sr86 content of these rocks is 0.7038 for Mt. Misery, 0.7041 for Soufriere, and 0.7053 for Carriacou. All the Sr87/Sr86 values from each center are the same within analytical uncertainty (??0.0002). The constancy of strontium isotopic data within each center supports the hypothesis that basalts and andesites for each specific center investigated are generated from the same source - in agreement with petrographic and major- and minor-element data. Strontium isotopic compositions and elemental concentrations, particularly of strontium and nickel, indicate that this source was mantle peridotite and that the relationship between the respective basalts and andesites is probably fractional crystallization. ?? 1971 Springer-Verlag.

  16. 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.

  17. 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.

  18. In-situ observations of bubble growth in basaltic, andesitic and rhyodacitic melts

    Science.gov (United States)

    Masotta, M.; Ni, H.; Keppler, H.

    2013-12-01

    Bubble growth strongly affects the physical properties of degassing magmas and their eruption dynamics. Natural samples and products from quench experiments provide only a snapshot of the final state of volatile exsolution, leaving the processes occurring during its early stages unconstrained. In order to fill this gap, we present in-situ high-temperature observations of bubble growth in magmas of different compositions (basalt, andesite and rhyodacite) at 1100 to 1240 °C and 1 bar, obtained using a moissanite cell apparatus. The data show that nucleation occurs at very small degrees of supersaturaturation (bubbles occurring simultaneously with the nucleation of crystals. During the early stages of exsolution, melt degassing is the driving mechanism of bubble growth, with coalescence becoming increasingly important as exsolution progresses. Ostwald ripening occurs only at the end of the process and only in basaltic melt. The average bubble growth rate (GR) ranges from 3.4*10-6 to 5.2*10-7 mm/s, with basalt and andesite showing faster growth rates than rhyodacite. The bubble number density (NB) at nucleation ranges from 1.8*108 to 7.9*107 cm-3 and decreases exponentially over time. While the rhyodacite melt maintained a well-sorted bubble-size distribution (BSD) through time, the BSD's of basalt and andesite are much more inhomogeneous. Our experimental observations demonstrate that bubble growth cannot be ascribed to a single mechanism but is rather a combination of many processes, which depend on the physical properties of the melt. Depending on coalescence rate, annealing of bubbles following a single nucleation event can produce complex bubble size distributions. In natural samples, such BSD's may be misinterpreted as resulting from several separate nucleation events. Incipient crystallization upon cooling of a magma may allow bubble nucleation already at very small degrees of supersaturation and could therefore be an important trigger for volatile release and

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

    Science.gov (United States)

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

    2017-01-01

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

  20. Network topology of olivine-basalt partial melts

    Science.gov (United States)

    Skemer, Philip; Chaney, Molly M.; Emmerich, Adrienne L.; Miller, Kevin J.; Zhu, Wen-lu

    2017-07-01

    The microstructural relationship between melt and solid grains in partially molten rocks influences many physical properties, including permeability, rheology, electrical conductivity and seismic wave speeds. In this study, the connectivity of melt networks in the olivine-basalt system is explored using a systematic survey of 3-D X-ray microtomographic data. Experimentally synthesized samples with 2 and 5 vol.% melt are analysed as a series of melt tubules intersecting at nodes. Each node is characterized by a coordination number (CN), which is the number of melt tubules that intersect at that location. Statistically representative volumes are described by coordination number distributions (CND). Polyhedral grains can be packed in many configurations yielding different CNDs, however widely accepted theory predicts that systems with small dihedral angles, such as olivine-basalt, should exhibit a predominant CN of four. In this study, melt objects are identified with CN = 2-8, however more than 50 per cent are CN = 4, providing experimental verification of this theoretical prediction. A conceptual model that considers the role of heterogeneity in local grain size and melt fraction is proposed to explain the formation of nodes with CN ≠ 4. Correctly identifying the melt network topology is essential to understanding the relationship between permeability and porosity, and hence the transport properties of partial molten mantle rocks.

  1. Pb, Sr, Nd, and Hf isotopic constraints on the origin of Hawaiian basalts and evidence for a unique mantle source

    International Nuclear Information System (INIS)

    Stille, P.

    1986-01-01

    Pb, Sr, Nd, and Hf isotopic relationships among basalts from the Hawaiian Islands suggest that these basalts were derived from three sources; the oceanic lithosphere (Kea end member), the depleted asthenosphere (posterosional end member) and a deep-mantle plume (Koolau end member). Hawaiian tholeiites are derived within the lithosphere and the isotopic trends collectively defined by the tholeiite data are interpreted as a plume-lithosphere mixing trend. The isotopic characteristics of late-stage basalts are derived from the tholeiite source (lithosphere + plume) with additional input from the lithosphere, asthenosphere, or both. These basalts probably originate from near the asthenosphere-lithosphere boundary. Posterosional basalts are derived from the depleted asthenosphere, but their isotopic characteristics have been slightly modified by either the plume or the source of previously erupted volcanics. The isotopic data require little or no mixing of asthenospheric material into the plume during tholeiite production and thus are consistent with the concept of a rapidly ascending, fluid-rich plume. In addition to providing a source of heat, the plume may supply volatiles to both the sources of tholeiites and posterosional basalts. The isotopic characteristics of the Koolau (plume) component are unique among OIB sources. If undifferentiated or 'primitive' mantle material still exists, then the radiogenic-isotope data for Koolau in combination with rare gas data for Hawaiian basalts in general suggest that the Hawaiian plume may be derived from such material. In any case, the Hawaiian Islands data, when compared to those of other OIB, serve to illustrate the isotopically diverse nature of mantle sources. (author)

  2. Estimate of long-term dissolution rate of basaltic glass. A case study on Mt. Fuji area

    International Nuclear Information System (INIS)

    Shikazono, Naotatsu; Takino, Akitsugu

    2002-01-01

    Bulk compositional, mineralogical and physical properties of weathered basaltic ash soil ('Andisol') derived mainly from Mt. Fuji were studied. Mineralogical studies revealed that the dominant primary material and weathering products are volcanic glass, allophane and halloysite and the sequence of weathering is volcanic glass → allophane → 10A halloysite → 7A halloysite. X-ray fluorescence analysis indicates that the relative elemental mobilities during the weathering is Na, Ca>K>Mg>P>Si>Ti, Fe>Al>Mn. The trends of soilwater chemistry (H 4 SiO 4 concentration) with depth were calculated based on dissolution - precipitation kinetics - fluid flow coupling model. In order to calculate the trends, the data on present-day annual rainfall, solubility of basalt glass, porosity and specific weight of soil, deposition rate of volcanic ash and grain size of volcanic glass were used. The calculated results were compared with analytical trends of soilwater chemistry. From this comparison the dissolution rate constant of basalt glass was estimated to be 10 -9.4 - 10 -9.2 (mole Si m -2 s -1 ). This value is consistent with previous experimental dissolution rate constant of basalt glass reported in the literature. (author)

  3. 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

  4. 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.

  5. 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

  6. The geochemical characteristics of basaltic and acidic volcanics around the Myojin depression in the Izu arc, Japan

    Science.gov (United States)

    Haraguchi, S.; Tamaki, K.; Kato, Y.; Machida, S.

    2012-12-01

    Around the Myojin Depression, westside of the Myojin-sho caldera in the Izu arc, seamounts are circular distributed and hydrothermal activity with sulfide deposition are found from the Baiyonneise Caldera, one of seamounts at the northern side. Some knoll chains distribute in the eastside of the Myojin Depression, and connect between these knolls. This circulator distribution of seamounts and connected knoll chains considered to the dykes are similar to the geographical features of the Kuroko Depositions in the Hokuroku Region, Northwest Japan (Tanahashi et al., 2008). Hydrothermal activities are also found from the other rifts (Urabe and Kusakabe 1990). Based on these observations, the cruise KT09-12 by R/V Tansei-Maru, Ocean Research Institute (ORI), University of Tokyo, investigated in the Myojin Rift. During the cruise, basaltic to dacitic volcanic rocks and some acidic plutonic rocks were recovered by dredge system. Herein, we present petrographical and chemical analyses of these rock samples with sample dredged by the cruise MW9507 by R/V MOANA WAVE, and consider the association with hydrothermal activities and depositions. Dredges during the cruise KT09-12 were obtained at the Daini-Beiyonneise Knoll at the northern side, Daisan-Beiyonneise Knoll at the southern side, and the Dragonborn Hill, small knoll chains, at the southeastern side of the depression. Many volcanic rocks are basalt, and recovered mainly from the Dragonborn Hill. Andesite and dacite was recovered from the Daini- and the Daini-Bayonneise Knoll. Tonalites were recovered from the Daisan-Bayonneise Knoll. Basalts from the Dragonborn Hill show less than 50% of SiO2 and more than 6 wt% and 0.88 wt% of MgO and TiO2 content. Basalts from the rift zone show depleted in the volcanic front (VF) side and enriched in the reararc (RA) side. The Dragonborn Hill is distributed near the VF, and basalts show depleted geochemical characteristics. However, these characteristics are different from the basalts

  7. 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

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

    Science.gov (United States)

    Barker, C.; Torkelson, B. E.

    1975-01-01

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

  9. Geochemical variability in the green stone belts of Goias (Brazil): the Hidrolina and Crixas sequences

    International Nuclear Information System (INIS)

    Rivalenti, G.; Mazzucchelli, M.; Finatti, C.; Girardi, V.A.V.; Candia, M.A.F.; Correia, C.T.; Coltorti, M.; Siena, F.

    1990-01-01

    The greenstone belts of Crixas and Hidrolina of Goias, Brazil are dismembered components of the same body or of originally adjacent belts. Their tectono-metamorphic history and stratigraphy is similar, as well as their igneous components (meta-komatiites, meta-basalts and felsic meta-volcanics). Chemically, they differ for the CaO and Al 2 O 3 versus MgO trends and for the behaviour of many incompatible and compatible trace elements (Cr, Ni, Ti, Sc, Y, Zr, P). The difference in the trace element behaviour has been mainly attributed to a compositional and modal heterogeneity of the mantle source, which was probably spinel-richer at Crixas than at Hidrolina. The X-ray fluorescence analytical methods employed for major and trace elements determinations on the 120 Crixas samples were the same as used at Hidrolina. (author)

  10. 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

  11. Optical and mechanical excitation thermography for impact response in basalt-carbon hybrid fiber-reinforced composite laminates

    OpenAIRE

    Zhang, Hai; Sfarra, Stefano; Sarasini, Fabrizio; Ibarra-Castanedo, Clemente; Perilli, Stefano; Fernandes, Henrique; Duan, Yuxia; Peeters, Jeroen; Avelidis, Nicholas P; Maldague, Xavier

    2017-01-01

    Abstract: In this paper, optical and mechanical excitation thermography were used to investigate basalt fiber reinforced polymer (BFRP), carbon fiber reinforced polymer (CFRP) and basalt-carbon fiber hybrid specimens subjected to impact loading. Interestingly, two different hybrid structures including sandwich-like and intercalated stacking sequence were used. Pulsed phase thermography (PPT), principal component thermography (PCT) and partial least squares thermography (PLST) were used to pro...

  12. 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.

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

    Indian Academy of Sciences (India)

    Several volcanic episodes occurred during Early- to Late-. Cretaceous are ... produce a new scene that has the best of orig- ... developed from an olivine basalt parent magma, ..... Marcelino E, Formaggio A and Maeda E 2009 Landslide.

  14. Evidence for intense hydrothermal alteration associated with flood basalt volcanism during the birth of the Azores Plateau

    Science.gov (United States)

    Bach, W.; Busch, A.; Genske, F. S.; Beier, C.; Krumm, S.

    2017-12-01

    initial stages of flood basalt activity. The extreme hydrothermal alteration may hence be directly linked to the prolonged magmatic period during which excess melting produced a 13-km thick igneous crust. Our results indicate that marine plateau-forming events may cause transient highs in hydrothermal flux rates.

  15. 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...

  16. 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...

  17. Effect of silane coupling agents on basalt fiber-epoxidized vegetable oil matrix composite materials analyzed by the single fiber fragmentation technique

    OpenAIRE

    Samper Madrigal, María Dolores; Petrucci, R.; Sánchez Nacher, Lourdes; Balart Gimeno, Rafael Antonio; Kenny, J. M.

    2015-01-01

    The fiber-matrix interfacial shear strength (IFSS) of biobased epoxy composites reinforced with basalt fiber was investigated by the fragmentation method. Basalt fibers were modified with four different silanes, (3-aminopropyl)trimethoxysilane, [3-(2-aminoethylamino)propyl]-trimethoxysilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane and (3-glycidyloxypropyl)trimethoxysilane to improve the adhesion between the basalt fiber and the resin. The analysis of the fiber tensile strength...

  18. The Impact of Space Flight on Survival and Interaction of Cupriavidus metallidurans CH34 with Basalt, a Volcanic Moon Analog Rock

    Directory of Open Access Journals (Sweden)

    Natalie Leys

    2017-04-01

    Full Text Available Microbe-mineral interactions have become of interest for space exploration as microorganisms could be used to biomine from extra-terrestrial material and extract elements useful as micronutrients in life support systems. This research aimed to identify the impact of space flight on the long-term survival of Cupriavidus metallidurans CH34 in mineral water and the interaction with basalt, a lunar-type rock in preparation for the ESA spaceflight experiment, BIOROCK. Therefore, C. metallidurans CH34 cells were suspended in mineral water supplemented with or without crushed basalt and send for 3 months on board the Russian FOTON-M4 capsule. Long-term storage had a significant impact on cell physiology and energy status (by flow cytometry analysis, plate count and intracellular ATP measurements as 60% of cells stored on ground lost their cell membrane potential, only 17% were still active, average ATP levels per cell were significantly lower and cultivability dropped to 1%. The cells stored in the presence of basalt and exposed to space flight conditions during storage however showed less dramatic changes in physiology, with only 16% of the cells lost their cell membrane potential and 24% were still active, leading to a higher cultivability (50% and indicating a general positive effect of basalt and space flight on survival. Microbe-mineral interactions and biofilm formation was altered by spaceflight as less biofilm was formed on the basalt during flight conditions. Leaching from basalt also changed (measured with ICP-OES, showing that cells release more copper from basalt and the presence of cells also impacted iron and magnesium concentration irrespective of the presence of basalt. The flight conditions thus could counteract some of the detrimental effects observed after the 3 month storage conditions.